------------------------------------------------------------------------------
with Atree; use Atree;
+with Checks; use Checks;
with Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Exp_Ch11; use Exp_Ch11;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
+with Expander; use Expander;
with Lib; use Lib;
with Lib.Load; use Lib.Load;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
+with Output; use Output;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
+with Sem_Cat; use Sem_Cat;
with Sem_Ch7; use Sem_Ch7;
with Sem_Ch8; use Sem_Ch8;
with Sem_Prag; use Sem_Prag;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
+with Sinput; use Sinput;
with Snames; use Snames;
with Stand; use Stand;
with Table;
-- * Depending on the elaboration model in effect, perform the following
-- actions:
--
- -- - Dynamic model - Diagnose guaranteed ABEs and install run-time
- -- conditional ABE checks.
+ -- - Dynamic model - Install run-time conditional ABE checks.
--
-- - SPARK model - Enforce the SPARK elaboration rules
--
- -- - Static model - Diagnose conditional/guaranteed ABEs, install
- -- run-time conditional ABE checks, and guarantee the elaboration
- -- of external units.
+ -- - Static model - Diagnose conditional ABEs, install run-time
+ -- conditional ABE checks, and guarantee the elaboration of
+ -- external units.
--
-- * Examine nested scenarios
--
-- The following switches may be used to control the behavior of the ABE
-- mechanism.
--
+ -- -gnatd_a stop elaboration checks on accept or select statement
+ --
+ -- The ABE mechanism stops the traversal of a task body when it
+ -- encounters an accept or a select statement. This behavior is
+ -- equivalent to restriction No_Entry_Calls_In_Elaboration_Code,
+ -- but without penalizing actual entry calls during elaboration.
+ --
+ -- -gnatd_e ignore entry calls and requeue statements for elaboration
+ --
+ -- The ABE mechanism does not generate N_Call_Marker nodes for
+ -- protected or task entry calls as well as requeue statements.
+ -- As a result, the calls and requeues are not recorded or
+ -- processed.
+ --
-- -gnatdE elaboration checks on predefined units
--
-- The ABE mechanism considers scenarios which appear in internal
-- actual subprograms through generic formal subprograms. As a
-- result, the calls are not recorded or processed.
--
- -- If switches -gnatd.G and -gnatdL are used together, then the
- -- ABE mechanism effectively ignores all calls which cause the
- -- elaboration flow to "leave" the instance.
- --
- -- -gnatdL ignore external calls from instances for elaboration
- --
- -- The ABE mechanism does not generate N_Call_Marker nodes for
- -- calls which occur in expanded instances, do not invoke generic
- -- actual subprograms through formal subprograms, and the target
- -- is external to the instance. As a result, the calls are not
- -- recorded or processed.
+ -- -gnatdL ignore activations and calls to instances for elaboration
--
- -- If switches -gnatd.G and -gnatdL are used together, then the
- -- ABE mechanism effectively ignores all calls which cause the
- -- elaboration flow to "leave" the instance.
+ -- The ABE mechanism ignores calls and task activations when they
+ -- target a subprogram or task type defined an external instance.
+ -- As a result, the calls and task activations are not processed.
--
-- -gnatd.o conservative elaboration order for indirect calls
--
-- target. As a result, it performs ABE checks and diagnostics on
-- the immediate call.
--
+ -- -gnatd_p ignore assertion pragmas for elaboration
+ --
+ -- The ABE mechanism does not generate N_Call_Marker nodes for
+ -- calls to subprograms which verify the run-time semantics of
+ -- the following assertion pragmas:
+ --
+ -- Invariant
+ -- Invariant'Class
+ -- Post
+ -- Post'Class
+ -- Postcondition
+ -- Type_Invariant
+ -- Type_Invariant_Class
+ --
+ -- As a result, the assertion expressions of the pragmas will not
+ -- be processed.
+ --
-- -gnatd.U ignore indirect calls for static elaboration
--
-- The ABE mechanism does not consider '[Unrestricted_]Access of
--
-- The complementary switch for -gnatel.
--
+ -- -gnatH legacy elaboration checking mode enabled
+ --
+ -- When this switch is in effect, the pre-18.x ABE model becomes
+ -- the defacto ABE model. This ammounts to cutting off all entry
+ -- points into the new ABE mechanism, and giving full control to
+ -- the old ABE mechanism.
+ --
+ -- -gnatJ permissive elaboration checking mode enabled
+ --
+ -- This switch activates the following switches:
+ --
+ -- -gnatd_a
+ -- -gnatd_e
+ -- -gnatd.G
+ -- -gnatdL
+ -- -gnatd_p
+ -- -gnatd.U
+ -- -gnatd.y
+ --
+ -- IMPORTANT: The behavior of the ABE mechanism becomes more
+ -- permissive at the cost of accurate diagnostics and runtime
+ -- ABE checks.
+ --
-- -gnatw.f turn on warnings for suspicious Subp'Access
--
-- The ABE mechanism treats '[Unrestricted_]Access of an entry,
--
-- 1) Add predicate Is_xxx.
--
- -- 2) Update predicates Is_Ada_Semantic_Target, Is_Bridge_Target, or
- -- Is_SPARK_Semantic_Target. If necessary, create a new category.
+ -- 2) Update the following predicates
+ --
+ -- Is_Ada_Semantic_Target
+ -- Is_Assertion_Pragma_Target
+ -- Is_Bridge_Target
+ -- Is_SPARK_Semantic_Target
+ --
+ -- If necessary, create a new category.
--
-- 3) Update the appropriate Info_xxx routine.
--
-- to pragma SPARK_Mode with value On, or starts one such region.
end record;
+ -- The following type captures relevant attributes which pertain to the
+ -- state of the Processing phase.
+
+ type Processing_Attributes is record
+ Suppress_Implicit_Pragmas : Boolean;
+ -- This flag is set when the Processing phase must not generate any
+ -- implicit Elaborate[_All] pragmas.
+
+ Within_Initial_Condition : Boolean;
+ -- This flag is set when the Processing phase is currently examining a
+ -- scenario which was reached from an initial condition procedure.
+
+ Within_Instance : Boolean;
+ -- This flag is set when the Processing phase is currently examining a
+ -- scenario which was reached from a scenario defined in an instance.
+
+ Within_Partial_Finalization : Boolean;
+ -- This flag is set when the Processing phase is currently examining a
+ -- scenario which was reached from a partial finalization procedure.
+
+ Within_Task_Body : Boolean;
+ -- This flag is set when the Processing phase is currently examining a
+ -- scenario which was reached from a task body.
+ end record;
+
+ Initial_State : constant Processing_Attributes :=
+ (Suppress_Implicit_Pragmas => False,
+ Within_Initial_Condition => False,
+ Within_Instance => False,
+ Within_Partial_Finalization => False,
+ Within_Task_Body => False);
+
-- The following type captures relevant attributes which pertain to a
-- target.
-- Return the set of elaboration attributes associated with unit Unit_Id
procedure Ensure_Prior_Elaboration
- (N : Node_Id;
- Unit_Id : Entity_Id;
- Prag_Nam : Name_Id;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (N : Node_Id;
+ Unit_Id : Entity_Id;
+ Prag_Nam : Name_Id;
+ State : Processing_Attributes);
-- Guarantee the elaboration of unit Unit_Id with respect to the main unit
-- by installing pragma Elaborate or Elaborate_All denoted by Prag_Nam. N
- -- denotes the related scenario. The flags should be set when the need for
- -- elaboration was initiated as follows:
- --
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- denotes the related scenario. State denotes the current state of the
+ -- Processing phase.
procedure Ensure_Prior_Elaboration_Dynamic
(N : Node_Id;
function Is_Ada_Semantic_Target (Id : Entity_Id) return Boolean;
pragma Inline (Is_Ada_Semantic_Target);
- -- Determine whether arbitrary entity Id nodes a source or internally
+ -- Determine whether arbitrary entity Id denodes a source or internally
-- generated subprogram which emulates Ada semantics.
+ function Is_Assertion_Pragma_Target (Id : Entity_Id) return Boolean;
+ pragma Inline (Is_Assertion_Pragma_Target);
+ -- Determine whether arbitrary entity Id denotes a procedure which varifies
+ -- the run-time semantics of an assertion pragma.
+
function Is_Bodiless_Subprogram (Subp_Id : Entity_Id) return Boolean;
pragma Inline (Is_Bodiless_Subprogram);
-- Determine whether subprogram Subp_Id will never have a body
generic
with procedure Process_Single_Activation
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- Obj_Id : Entity_Id;
- Task_Attrs : Task_Attributes;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ Obj_Id : Entity_Id;
+ Task_Attrs : Task_Attributes;
+ State : Processing_Attributes);
-- Perform ABE checks and diagnostics for task activation call Call
-- which activates task Obj_Id. Call_Attrs are the attributes of the
-- activation call. Task_Attrs are the attributes of the task type.
- -- The flags should be set when the processing was initiated as follows:
- --
- -- In_Init_Cond - initial condition procedure
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- State is the current state of the Processing phase.
procedure Process_Activation_Generic
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ State : Processing_Attributes);
-- Perform ABE checks and diagnostics for activation call Call by invoking
-- routine Process_Single_Activation on each task object being activated.
- -- Call_Attrs are the attributes of the activation call. The flags should
- -- be set when the processing was initiated as follows:
- --
- -- In_Init_Cond - initial condition procedure
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- Call_Attrs are the attributes of the activation call. State is the
+ -- current state of the Processing phase.
procedure Process_Conditional_ABE
- (N : Node_Id;
- In_Init_Cond : Boolean := False;
- In_Partial_Fin : Boolean := False;
- In_Task_Body : Boolean := False);
+ (N : Node_Id;
+ State : Processing_Attributes := Initial_State);
-- Top-level dispatcher for processing of various elaboration scenarios.
- -- Perform conditional ABE checks and diagnostics for scenario N. The flags
- -- should be set when the processing was initiated as follows:
- --
- -- In_Init_Cond - initial condition procedure
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- Perform conditional ABE checks and diagnostics for scenario N. State
+ -- is the current state of the Processing phase.
procedure Process_Conditional_ABE_Access
- (Attr : Node_Id;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Attr : Node_Id;
+ State : Processing_Attributes);
-- Perform ABE checks and diagnostics for 'Access to entry, operator, or
- -- subprogram denoted by Attr. The flags should be set when the processing
- -- was initiated as follows:
- --
- -- In_Init_Cond - initial condition procedure
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- subprogram denoted by Attr. State is the current state of the Processing
+ -- phase.
procedure Process_Conditional_ABE_Activation_Impl
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- Obj_Id : Entity_Id;
- Task_Attrs : Task_Attributes;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ Obj_Id : Entity_Id;
+ Task_Attrs : Task_Attributes;
+ State : Processing_Attributes);
-- Perform common conditional ABE checks and diagnostics for call Call
-- which activates task Obj_Id ignoring the Ada or SPARK rules. Call_Attrs
-- are the attributes of the activation call. Task_Attrs are the attributes
- -- of the task type. The flags should be set when the processing was
- -- initiated as follows:
- --
- -- In_Init_Cond - initial condition procedure
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- of the task type. State is the current state of the Processing phase.
procedure Process_Conditional_ABE_Call
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- Target_Id : Entity_Id;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ Target_Id : Entity_Id;
+ State : Processing_Attributes);
-- Top-level dispatcher for processing of calls. Perform ABE checks and
-- diagnostics for call Call which invokes target Target_Id. Call_Attrs
- -- are the attributes of the call. The flags should be set when the
- -- processing was initiated as follows:
- --
- -- In_Init_Cond - initial condition procedure
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- are the attributes of the call. State is the current state of the
+ -- Processing phase.
procedure Process_Conditional_ABE_Call_Ada
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- Target_Id : Entity_Id;
- Target_Attrs : Target_Attributes;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ Target_Id : Entity_Id;
+ Target_Attrs : Target_Attributes;
+ State : Processing_Attributes);
-- Perform ABE checks and diagnostics for call Call which invokes target
-- Target_Id using the Ada rules. Call_Attrs are the attributes of the
- -- call. Target_Attrs are attributes of the target. The flags should be
- -- set when the processing was initiated as follows:
- --
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- call. Target_Attrs are attributes of the target. State is the current
+ -- state of the Processing phase.
procedure Process_Conditional_ABE_Call_SPARK
- (Call : Node_Id;
- Target_Id : Entity_Id;
- Target_Attrs : Target_Attributes;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Call : Node_Id;
+ Target_Id : Entity_Id;
+ Target_Attrs : Target_Attributes;
+ State : Processing_Attributes);
-- Perform ABE checks and diagnostics for call Call which invokes target
-- Target_Id using the SPARK rules. Target_Attrs denotes the attributes of
- -- the target. The flags should be set when the processing was initiated as
- -- follows:
- --
- -- In_Init_Cond - initial condition procedure
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- the target. State is the current state of the Processing phase.
procedure Process_Conditional_ABE_Instantiation
- (Exp_Inst : Node_Id;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Exp_Inst : Node_Id;
+ State : Processing_Attributes);
-- Top-level dispatcher for processing of instantiations. Perform ABE
- -- checks and diagnostics for expanded instantiation Exp_Inst. The flags
- -- should be set when the processing was initiated as follows:
- --
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- checks and diagnostics for expanded instantiation Exp_Inst. State is
+ -- the current state of the Processing phase.
procedure Process_Conditional_ABE_Instantiation_Ada
- (Exp_Inst : Node_Id;
- Inst : Node_Id;
- Inst_Attrs : Instantiation_Attributes;
- Gen_Id : Entity_Id;
- Gen_Attrs : Target_Attributes;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Exp_Inst : Node_Id;
+ Inst : Node_Id;
+ Inst_Attrs : Instantiation_Attributes;
+ Gen_Id : Entity_Id;
+ Gen_Attrs : Target_Attributes;
+ State : Processing_Attributes);
-- Perform ABE checks and diagnostics for expanded instantiation Exp_Inst
-- of generic Gen_Id using the Ada rules. Inst is the instantiation node.
-- Inst_Attrs are the attributes of the instance. Gen_Attrs denotes the
- -- attributes of the generic. The flags should be set when the processing
- -- was initiated as follows:
- --
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- attributes of the generic. State is the current state of the Processing
+ -- phase.
procedure Process_Conditional_ABE_Instantiation_SPARK
- (Inst : Node_Id;
- Gen_Id : Entity_Id;
- Gen_Attrs : Target_Attributes;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Inst : Node_Id;
+ Gen_Id : Entity_Id;
+ Gen_Attrs : Target_Attributes;
+ State : Processing_Attributes);
-- Perform ABE checks and diagnostics for instantiation Inst of generic
-- Gen_Id using the SPARK rules. Gen_Attrs denotes the attributes of the
- -- generic. The flags should be set when the processing was initiated as
- -- follows:
- --
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ -- generic. State is the current state of the Processing phase.
procedure Process_Conditional_ABE_Variable_Assignment (Asmt : Node_Id);
-- Top-level dispatcher for processing of variable assignments. Perform ABE
-- guaranteed ABE.
procedure Process_Guaranteed_ABE_Activation_Impl
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- Obj_Id : Entity_Id;
- Task_Attrs : Task_Attributes;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ Obj_Id : Entity_Id;
+ Task_Attrs : Task_Attributes;
+ State : Processing_Attributes);
-- Perform common guaranteed ABE checks and diagnostics for call Call which
-- activates task Obj_Id ignoring the Ada or SPARK rules. Call_Attrs are
-- the attributes of the activation call. Task_Attrs are the attributes of
- -- the task type. The following parameters are provided for compatibility
- -- and are not used.
- --
- -- In_Init_Cond
- -- In_Partial_Fin
- -- In_Task_Body
+ -- the task type. State is provided for compatibility and is not used.
procedure Process_Guaranteed_ABE_Call
(Call : Node_Id;
pragma Inline (Static_Elaboration_Checks);
-- Determine whether the static model is in effect
- procedure Traverse_Body
- (N : Node_Id;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean);
- -- Inspect the declarations and statements of subprogram body N for
- -- suitable elaboration scenarios and process them. The flags should
- -- be set when the processing was initiated as follows:
- --
- -- In_Init_Cond - initial condition procedure
- -- In_Partial_Fin - partial finalization procedure
- -- In_Task_Body - task body
+ procedure Traverse_Body (N : Node_Id; State : Processing_Attributes);
+ -- Inspect the declarative and statement lists of subprogram body N for
+ -- suitable elaboration scenarios and process them. State is the current
+ -- state of the Processing phase.
procedure Update_Elaboration_Scenario (New_N : Node_Id; Old_N : Node_Id);
pragma Inline (Update_Elaboration_Scenario);
-----------------------
procedure Build_Call_Marker (N : Node_Id) is
- function In_External_Context
- (Call : Node_Id;
- Target_Id : Entity_Id) return Boolean;
- pragma Inline (In_External_Context);
- -- Determine whether target Target_Id is external to call N which must
- -- reside within an instance.
-
function In_Premature_Context (Call : Node_Id) return Boolean;
-- Determine whether call Call appears within a premature context
-- Determine whether subprogram Subp_Id denotes a generic formal
-- subprogram which appears in the "prologue" of an instantiation.
- -------------------------
- -- In_External_Context --
- -------------------------
-
- function In_External_Context
- (Call : Node_Id;
- Target_Id : Entity_Id) return Boolean
- is
- Target_Decl : constant Node_Id := Unit_Declaration_Node (Target_Id);
-
- Inst : Node_Id;
- Inst_Body : Node_Id;
- Inst_Decl : Node_Id;
-
- begin
- -- Performance note: parent traversal
-
- Inst := Find_Enclosing_Instance (Call);
-
- -- The call appears within an instance
-
- if Present (Inst) then
-
- -- The call comes from the main unit and the target does not
-
- if In_Extended_Main_Code_Unit (Call)
- and then not In_Extended_Main_Code_Unit (Target_Decl)
- then
- return True;
-
- -- Otherwise the target declaration must not appear within the
- -- instance spec or body.
-
- else
- Extract_Instance_Attributes
- (Exp_Inst => Inst,
- Inst_Decl => Inst_Decl,
- Inst_Body => Inst_Body);
-
- -- Performance note: parent traversal
-
- return not In_Subtree
- (N => Target_Decl,
- Root1 => Inst_Decl,
- Root2 => Inst_Body);
- end if;
- end if;
-
- return False;
- end In_External_Context;
-
--------------------------
-- In_Premature_Context --
--------------------------
-- Local variables
- Call_Attrs : Call_Attributes;
- Call_Nam : Node_Id;
- Marker : Node_Id;
- Target_Id : Entity_Id;
+ Call_Attrs : Call_Attributes;
+ Call_Nam : Node_Id;
+ Marker : Node_Id;
+ Target_Attrs : Target_Attributes;
+ Target_Id : Entity_Id;
-- Start of processing for Build_Call_Marker
begin
+ -- Nothing to do when switch -gnatH (legacy elaboration checking mode
+ -- enabled) is in effect because the legacy ABE mechanism does not need
+ -- to carry out this action.
+
+ if Legacy_Elaboration_Checks then
+ return;
+
-- Nothing to do for ASIS. As a result, ABE checks and diagnostics are
-- not performed in this mode.
- if ASIS_Mode then
+ elsif ASIS_Mode then
return;
-- Nothing to do when the call is being preanalyzed as the marker will
then
return;
- -- Nothing to do when the call is analyzed/resolved too early within an
- -- intermediate context.
-
- -- Performance note: parent traversal
+ -- Nothing to do when the input denotes entry call or requeue statement,
+ -- and switch -gnatd_e (ignore entry calls and requeue statements for
+ -- elaboration) is in effect.
- elsif In_Premature_Context (N) then
+ elsif Debug_Flag_Underscore_E
+ and then Nkind_In (N, N_Entry_Call_Statement, N_Requeue_Statement)
+ then
return;
end if;
and then Is_Generic_Formal_Subp (Entity (Call_Nam))
then
return;
+
+ -- Nothing to do when the call is analyzed/resolved too early within an
+ -- intermediate context. This check is saved for last because it incurs
+ -- a performance penalty.
+
+ -- Performance note: parent traversal
+
+ elsif In_Premature_Context (N) then
+ return;
end if;
Extract_Call_Attributes
Target_Id => Target_Id,
Attrs => Call_Attrs);
- -- Nothing to do when the call appears within the expanded spec or
- -- body of an instantiated generic, the call does not invoke a generic
- -- formal subprogram, the target is external to the instance, and switch
- -- -gnatdL (ignore external calls from instances for elaboration) is in
- -- effect. This behaviour approximates that of the old ABE mechanism.
-
- if Debug_Flag_LL
- and then not Is_Generic_Formal_Subp (Entity (Call_Nam))
+ Extract_Target_Attributes
+ (Target_Id => Target_Id,
+ Attrs => Target_Attrs);
- -- Performance note: parent traversal
+ -- Nothing to do when the call invokes an assertion pragma procedure
+ -- and switch -gnatd_p (ignore assertion pragmas for elaboration) is
+ -- in effect.
- and then In_External_Context
- (Call => N,
- Target_Id => Target_Id)
+ if Debug_Flag_Underscore_P
+ and then Is_Assertion_Pragma_Target (Target_Id)
then
return;
-- Source calls to source targets are always considered because they
-- reflect the original call graph.
- elsif Comes_From_Source (Target_Id) and then Call_Attrs.From_Source then
+ elsif Target_Attrs.From_Source and then Call_Attrs.From_Source then
null;
-- A call to a source function which acts as the default expression in
-- another call requires special detection.
- elsif Comes_From_Source (Target_Id)
+ elsif Target_Attrs.From_Source
and then Nkind (N) = N_Function_Call
and then Is_Default_Expression (N)
then
-- Start of processing for Build_Variable_Reference_Marker
begin
+ -- Nothing to do when switch -gnatH (legacy elaboration checking mode
+ -- enabled) is in effect because the legacy ABE mechanism does not need
+ -- to carry out this action.
+
+ if Legacy_Elaboration_Checks then
+ return;
+
-- Nothing to do for ASIS. As a result, ABE checks and diagnostics are
-- not performed in this mode.
- if ASIS_Mode then
+ elsif ASIS_Mode then
return;
-- Nothing to do when the reference is being preanalyzed as the marker
procedure Check_Elaboration_Scenarios is
begin
+ -- Nothing to do when switch -gnatH (legacy elaboration checking mode
+ -- enabled) is in effect because the legacy ABE mechanism does not need
+ -- to carry out this action.
+
+ if Legacy_Elaboration_Checks then
+ return;
+
-- Nothing to do for ASIS. As a result, no ABE checks and diagnostics
-- are performed in this mode.
- if ASIS_Mode then
+ elsif ASIS_Mode then
return;
end if;
else
Ensure_Prior_Elaboration
- (N => N,
- Unit_Id => Find_Top_Unit (Constit_Id),
- Prag_Nam => Name_Elaborate,
- In_Partial_Fin => False,
- In_Task_Body => False);
+ (N => N,
+ Unit_Id => Find_Top_Unit (Constit_Id),
+ Prag_Nam => Name_Elaborate,
+ State => Initial_State);
end if;
end if;
end Check_SPARK_Constituent;
------------------------------
procedure Ensure_Prior_Elaboration
- (N : Node_Id;
- Unit_Id : Entity_Id;
- Prag_Nam : Name_Id;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (N : Node_Id;
+ Unit_Id : Entity_Id;
+ Prag_Nam : Name_Id;
+ State : Processing_Attributes)
is
begin
pragma Assert (Nam_In (Prag_Nam, Name_Elaborate, Name_Elaborate_All));
+ -- Nothing to do when the caller has suppressed the generation of
+ -- implicit Elaborate[_All] pragmas.
+
+ if State.Suppress_Implicit_Pragmas then
+ return;
+
-- Nothing to do when the need for prior elaboration came from a partial
-- finalization routine which occurs in an initialization context. This
-- behaviour parallels that of the old ABE mechanism.
- if In_Partial_Fin then
+ elsif State.Within_Partial_Finalization then
return;
-- Nothing to do when the need for prior elaboration came from a task
-- body and switch -gnatd.y (disable implicit pragma Elaborate_All on
-- task bodies) is in effect.
- elsif Debug_Flag_Dot_Y and then In_Task_Body then
+ elsif Debug_Flag_Dot_Y and then State.Within_Task_Body then
return;
-- Nothing to do when the unit is elaborated prior to the main unit.
Loc : constant Source_Ptr := Sloc (Main_Cunit);
Unit_Cunit : constant Node_Id := Compilation_Unit (Unit_Id);
- Is_Instantiation : constant Boolean :=
- Nkind (N) in N_Generic_Instantiation;
-
Clause : Node_Id;
Elab_Attrs : Elaboration_Attributes;
Items : List_Id;
Append_To (Items, Clause);
end if;
- -- Instantiations require an implicit Elaborate because Elaborate_All is
- -- too conservative and may introduce non-existent elaboration cycles.
+ -- Mark the with clause depending on the pragma required
- if Is_Instantiation then
+ if Prag_Nam = Name_Elaborate then
Set_Elaborate_Desirable (Clause);
-
- -- Otherwise generate an implicit Elaborate_All
-
else
Set_Elaborate_All_Desirable (Clause);
end if;
or else Is_Task_Entry (Id);
end Is_Ada_Semantic_Target;
+ --------------------------------
+ -- Is_Assertion_Pragma_Target --
+ --------------------------------
+
+ function Is_Assertion_Pragma_Target (Id : Entity_Id) return Boolean is
+ begin
+ return
+ Is_Default_Initial_Condition_Proc (Id)
+ or else Is_Initial_Condition_Proc (Id)
+ or else Is_Invariant_Proc (Id)
+ or else Is_Partial_Invariant_Proc (Id)
+ or else Is_Postconditions_Proc (Id);
+ end Is_Assertion_Pragma_Target;
+
----------------------------
-- Is_Bodiless_Subprogram --
----------------------------
-- Start of processing for Kill_Elaboration_Scenario
begin
+ -- Nothing to do when switch -gnatH (legacy elaboration checking mode
+ -- enabled) is in effect because the legacy ABE lechanism does not need
+ -- to carry out this action.
+
+ if Legacy_Elaboration_Checks then
+ return;
+ end if;
+
-- Eliminate a recorded scenario when it appears within dead code
-- because it will not be executed at elaboration time.
--------------------------------
procedure Process_Activation_Generic
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ State : Processing_Attributes)
is
procedure Process_Task_Object (Obj_Id : Entity_Id; Typ : Entity_Id);
-- Perform ABE checks and diagnostics for object Obj_Id with type Typ.
Attrs => Task_Attrs);
Process_Single_Activation
- (Call => Call,
- Call_Attrs => Call_Attrs,
- Obj_Id => Obj_Id,
- Task_Attrs => Task_Attrs,
- In_Init_Cond => In_Init_Cond,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (Call => Call,
+ Call_Attrs => Call_Attrs,
+ Obj_Id => Obj_Id,
+ Task_Attrs => Task_Attrs,
+ State => State);
-- Examine the component type when the object is an array
------------------------------------
procedure Process_Conditional_ABE_Access
- (Attr : Node_Id;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Attr : Node_Id;
+ State : Processing_Attributes)
is
function Build_Access_Marker (Target_Id : Entity_Id) return Node_Id;
pragma Inline (Build_Access_Marker);
if Debug_Flag_Dot_O then
Process_Conditional_ABE
- (N => Build_Access_Marker (Target_Id),
- In_Init_Cond => In_Init_Cond,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (N => Build_Access_Marker (Target_Id),
+ State => State);
-- Otherwise ensure that the unit with the corresponding body is
-- elaborated prior to the main unit.
else
Ensure_Prior_Elaboration
- (N => Attr,
- Unit_Id => Target_Attrs.Unit_Id,
- Prag_Nam => Name_Elaborate_All,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (N => Attr,
+ Unit_Id => Target_Attrs.Unit_Id,
+ Prag_Nam => Name_Elaborate_All,
+ State => State);
end if;
end Process_Conditional_ABE_Access;
---------------------------------------------
procedure Process_Conditional_ABE_Activation_Impl
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- Obj_Id : Entity_Id;
- Task_Attrs : Task_Attributes;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ Obj_Id : Entity_Id;
+ Task_Attrs : Task_Attributes;
+ State : Processing_Attributes)
is
Check_OK : constant Boolean :=
not Is_Ignored_Ghost_Entity (Obj_Id)
Root : constant Node_Id := Root_Scenario;
+ New_State : Processing_Attributes := State;
+ -- Each step of the Processing phase constitutes a new state
+
begin
-- Output relevant information when switch -gnatel (info messages on
-- implicit Elaborate[_All] pragmas) is in effect.
("info: activation of & during elaboration", Call, Obj_Id);
end if;
+ -- Nothing to do when the call activates a task whose type is defined
+ -- within an instance and switch -gnatdL (ignore activations and calls
+ -- to instances for elaboration) is in effect.
+
+ if Debug_Flag_LL
+ and then In_External_Instance
+ (N => Call,
+ Target_Decl => Task_Attrs.Task_Decl)
+ then
+ return;
+
-- Nothing to do when the activation is a guaranteed ABE
- if Is_Known_Guaranteed_ABE (Call) then
+ elsif Is_Known_Guaranteed_ABE (Call) then
return;
-- Nothing to do when the root scenario appears at the declaration
-- level and the task is in the same unit, but outside this context.
-
+ --
-- task type Task_Typ; -- task declaration
-
+ --
-- procedure Proc is
-- function A ... is
-- begin
-- end;
-- ...
-- end A;
-
+ --
-- X : ... := A; -- root scenario
-- ...
-
+ --
-- task body Task_Typ is
-- ...
-- end Task_Typ;
-
+ --
-- In the example above, the context of X is the declarative list of
-- Proc. The "elaboration" of X may reach the activation of T whose body
-- is defined outside of X's context. The task body is relevant only
return;
-- Nothing to do when the activation is ABE-safe
-
+ --
-- generic
-- package Gen is
-- task type Task_Typ;
-- end Gen;
-
+ --
-- package body Gen is
-- task body Task_Typ is
-- begin
-- ...
-- end Task_Typ;
-- end Gen;
-
+ --
-- with Gen;
-- procedure Main is
-- package Nested is
- -- ...
- -- end Nested;
-
- -- package body Nested is
-- package Inst is new Gen;
-- T : Inst.Task_Typ;
- -- [begin]
-- <activation call> -- safe activation
-- end Nested;
-- ...
then
-- If the root scenario appears prior to the task body, then this is
-- a possible ABE with respect to the root scenario.
-
+ --
-- task type Task_Typ;
-
+ --
-- function A ... is
-- begin
-- if Some_Condition then
-- declare
-- package Pack is
- -- ...
- -- end Pack;
-
- -- package body Pack is
-- T : Task_Typ;
- -- [begin]
- -- <activation call> -- activation of T
- -- end Pack;
+ -- end Pack; -- activation of T
-- ...
-- end A;
-
+ --
-- X : ... := A; -- root scenario
-
+ --
-- task body Task_Typ is -- task body
-- ...
-- end Task_Typ;
-
+ --
-- Y : ... := A; -- root scenario
-
+ --
-- IMPORTANT: The activation of T is a possible ABE for X, but
-- not for Y. Intalling an unconditional ABE raise prior to the
-- activation call would be wrong as it will fail for Y as well
-- a partial finalization context because this leads to confusing
-- noise.
- if In_Partial_Fin then
+ if State.Within_Partial_Finalization then
null;
-- ABE diagnostics are emitted only in the static model because
Target_Id => Task_Attrs.Spec_Id,
Target_Decl => Task_Attrs.Task_Decl,
Target_Body => Task_Attrs.Body_Decl);
+
+ -- Update the state of the Processing phase to indicate that
+ -- no implicit Elaborate[_All] pragmas must be generated from
+ -- this point on.
+ --
+ -- task type Task_Typ;
+ --
+ -- function A ... is
+ -- begin
+ -- if Some_Condition then
+ -- declare
+ -- package Pack is
+ -- <ABE check>
+ -- T : Task_Typ;
+ -- end Pack; -- activation of T
+ -- ...
+ -- end A;
+ --
+ -- X : ... := A;
+ --
+ -- task body Task_Typ is
+ -- begin
+ -- External.Subp; -- imparts Elaborate_All
+ -- end Task_Typ;
+ --
+ -- If Some_Condition is True, then the ABE check will fail at
+ -- runtime and the call to External.Subp will never take place,
+ -- rendering the implicit Elaborate_All useless.
+ --
+ -- If Some_Condition is False, then the call to External.Subp
+ -- will never take place, rendering the implicit Elaborate_All
+ -- useless.
+
+ New_State.Suppress_Implicit_Pragmas := True;
end if;
end if;
Id => Task_Attrs.Unit_Id);
end if;
+ -- Update the state of the Processing phase to indicate that any further
+ -- traversal is now within a task body.
+
+ New_State.Within_Task_Body := True;
+
-- Both the activation call and task type are subject to SPARK_Mode
-- On, this triggers the SPARK rules for task activation. Compared to
-- calls and instantiations, task activation in SPARK does not require
else
Ensure_Prior_Elaboration
- (N => Call,
- Unit_Id => Task_Attrs.Unit_Id,
- Prag_Nam => Name_Elaborate_All,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (N => Call,
+ Unit_Id => Task_Attrs.Unit_Id,
+ Prag_Nam => Name_Elaborate_All,
+ State => New_State);
end if;
Traverse_Body
- (N => Task_Attrs.Body_Decl,
- In_Init_Cond => In_Init_Cond,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => True);
+ (N => Task_Attrs.Body_Decl,
+ State => New_State);
end Process_Conditional_ABE_Activation_Impl;
procedure Process_Conditional_ABE_Activation is
----------------------------------
procedure Process_Conditional_ABE_Call
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- Target_Id : Entity_Id;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ Target_Id : Entity_Id;
+ State : Processing_Attributes)
is
function In_Initialization_Context (N : Node_Id) return Boolean;
-- Determine whether arbitrary node N appears within a type init proc,
-- Local variables
- Init_Cond_On : Boolean;
- Partial_Fin_On : Boolean;
SPARK_Rules_On : Boolean;
Target_Attrs : Target_Attributes;
+ New_State : Processing_Attributes := State;
+ -- Each step of the Processing phase constitutes a new state
+
-- Start of processing for Process_Conditional_ABE_Call
begin
(Target_Id => Target_Id,
Attrs => Target_Attrs);
- -- The call occurs in an initial condition context when a prior
- -- scenario is already in that mode, or when the target denotes
- -- an Initial_Condition procedure.
-
- Init_Cond_On :=
- In_Init_Cond or else Is_Initial_Condition_Proc (Target_Id);
-
- -- The call occurs in a partial finalization context when a prior
- -- scenario is already in that mode, or when the target denotes a
- -- [Deep_]Finalize primitive or a finalizer within an initialization
- -- context.
-
- Partial_Fin_On := In_Partial_Fin or else Is_Partial_Finalization_Proc;
-
-- The SPARK rules are in effect when both the call and target are
-- subject to SPARK_Mode On.
return;
end if;
+ -- Nothing to do when the call invokes a target defined within an
+ -- instance and switch -gnatdL (ignore activations and calls to
+ -- instances for elaboration) is in effect.
+
+ if Debug_Flag_LL
+ and then In_External_Instance
+ (N => Call,
+ Target_Decl => Target_Attrs.Spec_Decl)
+ then
+ return;
+
-- Nothing to do when the call is a guaranteed ABE
- if Is_Known_Guaranteed_ABE (Call) then
+ elsif Is_Known_Guaranteed_ABE (Call) then
return;
-- Nothing to do when the root scenario appears at the declaration level
-- and the target is in the same unit, but outside this context.
-
+ --
-- function B ...; -- target declaration
-
+ --
-- procedure Proc is
-- function A ... is
-- begin
-- return B; -- call site
-- ...
-- end A;
-
+ --
-- X : ... := A; -- root scenario
-- ...
-
+ --
-- function B ... is
-- ...
-- end B;
-
+ --
-- In the example above, the context of X is the declarative region of
-- Proc. The "elaboration" of X may eventually reach B which is defined
-- outside of X's context. B is relevant only when Proc is invoked, but
elsif Is_Up_Level_Target (Target_Attrs.Spec_Decl) then
return;
+ end if;
+
+ -- The call occurs in an initial condition context when a prior scenario
+ -- is already in that mode, or when the target is an Initial_Condition
+ -- procedure. Update the state of the Processing phase to reflect this.
+
+ New_State.Within_Initial_Condition :=
+ New_State.Within_Initial_Condition
+ or else Is_Initial_Condition_Proc (Target_Id);
+
+ -- The call occurs in a partial finalization context when a prior
+ -- scenario is already in that mode, or when the target denotes a
+ -- [Deep_]Finalize primitive or a finalizer within an initialization
+ -- context. Update the state of the Processing phase to reflect this.
+
+ New_State.Within_Partial_Finalization :=
+ New_State.Within_Partial_Finalization
+ or else Is_Partial_Finalization_Proc;
-- The SPARK rules are in effect. Note that -gnatd.v (enforce SPARK
-- elaboration rules in SPARK code) is intentionally not taken into
-- account here because Process_Conditional_ABE_Call_SPARK has two
-- separate modes of operation.
- elsif SPARK_Rules_On then
+ if SPARK_Rules_On then
Process_Conditional_ABE_Call_SPARK
- (Call => Call,
- Target_Id => Target_Id,
- Target_Attrs => Target_Attrs,
- In_Init_Cond => Init_Cond_On,
- In_Partial_Fin => Partial_Fin_On,
- In_Task_Body => In_Task_Body);
+ (Call => Call,
+ Target_Id => Target_Id,
+ Target_Attrs => Target_Attrs,
+ State => New_State);
-- Otherwise the Ada rules are in effect
else
Process_Conditional_ABE_Call_Ada
- (Call => Call,
- Call_Attrs => Call_Attrs,
- Target_Id => Target_Id,
- Target_Attrs => Target_Attrs,
- In_Partial_Fin => Partial_Fin_On,
- In_Task_Body => In_Task_Body);
+ (Call => Call,
+ Call_Attrs => Call_Attrs,
+ Target_Id => Target_Id,
+ Target_Attrs => Target_Attrs,
+ State => New_State);
end if;
-- Inspect the target body (and barried function) for other suitable
-- elaboration scenarios.
Traverse_Body
- (N => Target_Attrs.Body_Barf,
- In_Init_Cond => Init_Cond_On,
- In_Partial_Fin => Partial_Fin_On,
- In_Task_Body => In_Task_Body);
+ (N => Target_Attrs.Body_Barf,
+ State => New_State);
Traverse_Body
- (N => Target_Attrs.Body_Decl,
- In_Init_Cond => Init_Cond_On,
- In_Partial_Fin => Partial_Fin_On,
- In_Task_Body => In_Task_Body);
+ (N => Target_Attrs.Body_Decl,
+ State => New_State);
end Process_Conditional_ABE_Call;
--------------------------------------
--------------------------------------
procedure Process_Conditional_ABE_Call_Ada
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- Target_Id : Entity_Id;
- Target_Attrs : Target_Attributes;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ Target_Id : Entity_Id;
+ Target_Attrs : Target_Attributes;
+ State : Processing_Attributes)
is
Check_OK : constant Boolean :=
not Call_Attrs.Ghost_Mode_Ignore
Root : constant Node_Id := Root_Scenario;
+ New_State : Processing_Attributes := State;
+ -- Each step of the Processing phase constitutes a new state
+
begin
-- Nothing to do for an Ada dispatching call because there are no ABE
-- diagnostics for either models. ABE checks for the dynamic model are
return;
-- Nothing to do when the call is ABE-safe
-
+ --
-- generic
-- function Gen ...;
-
+ --
-- function Gen ... is
-- begin
-- ...
-- end Gen;
-
+ --
-- with Gen;
-- procedure Main is
-- function Inst is new Gen;
then
-- If the root scenario appears prior to the target body, then this
-- is a possible ABE with respect to the root scenario.
-
+ --
-- function B ...;
-
+ --
-- function A ... is
-- begin
-- if Some_Condition then
-- return B; -- call site
-- ...
-- end A;
-
+ --
-- X : ... := A; -- root scenario
-
+ --
-- function B ... is -- target body
-- ...
-- end B;
-
+ --
-- Y : ... := A; -- root scenario
-
+ --
-- IMPORTANT: The call to B from A is a possible ABE for X, but not
-- for Y. Installing an unconditional ABE raise prior to the call to
-- B would be wrong as it will fail for Y as well, but in Y's case
-- partial finalization context because this leads to confusing
-- noise.
- if In_Partial_Fin then
+ if State.Within_Partial_Finalization then
null;
-- ABE diagnostics are emitted only in the static model because
Target_Id => Target_Attrs.Spec_Id,
Target_Decl => Target_Attrs.Spec_Decl,
Target_Body => Target_Attrs.Body_Decl);
+
+ -- Update the state of the Processing phase to indicate that
+ -- no implicit Elaborate[_All] pragmas must be generated from
+ -- this point on.
+ --
+ -- function B ...;
+ --
+ -- function A ... is
+ -- begin
+ -- if Some_Condition then
+ -- <ABE check>
+ -- return B;
+ -- ...
+ -- end A;
+ --
+ -- X : ... := A;
+ --
+ -- function B ... is
+ -- External.Subp; -- imparts Elaborate_All
+ -- end B;
+ --
+ -- If Some_Condition is True, then the ABE check will fail at
+ -- runtime and the call to External.Subp will never take place,
+ -- rendering the implicit Elaborate_All useless.
+ --
+ -- If Some_Condition is False, then the call to External.Subp
+ -- will never take place, rendering the implicit Elaborate_All
+ -- useless.
+
+ New_State.Suppress_Implicit_Pragmas := True;
end if;
end if;
if Call_Attrs.Elab_Checks_OK then
Ensure_Prior_Elaboration
- (N => Call,
- Unit_Id => Target_Attrs.Unit_Id,
- Prag_Nam => Name_Elaborate_All,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (N => Call,
+ Unit_Id => Target_Attrs.Unit_Id,
+ Prag_Nam => Name_Elaborate_All,
+ State => New_State);
end if;
end Process_Conditional_ABE_Call_Ada;
----------------------------------------
procedure Process_Conditional_ABE_Call_SPARK
- (Call : Node_Id;
- Target_Id : Entity_Id;
- Target_Attrs : Target_Attributes;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Call : Node_Id;
+ Target_Id : Entity_Id;
+ Target_Attrs : Target_Attributes;
+ State : Processing_Attributes)
is
Region : Node_Id;
then
-- If the call appears prior to the target body, then the call must
-- appear within the early call region of the target body.
-
+ --
-- function B ...;
-
+ --
-- X : ... := B; -- call site
-
+ --
-- <preelaborable construct 1> --+
-- ... | early call region
-- <preelaborable construct N> --+
-
+ --
-- function B ... is -- target body
-- ...
-- end B;
-
+ --
-- When the call to B is not nested within some other scenario, the
-- call is automatically illegal because it can never appear in the
-- early call region of B's body. This is equivalent to a guaranteed
-- ABE.
-
+ --
-- <preelaborable construct 1> --+
-- |
-- function B ...; |
-- end A; |
-- |
-- <preelaborable construct N> --+
-
+ --
-- function B ... is -- target body
-- ...
-- end B;
-
+ --
-- When the call to B is nested within some other scenario, the call
-- is always ABE-safe. It is not immediately obvious why this is the
-- case. The elaboration safety follows from the early call region
-- rule being applied to ALL calls preceding their associated bodies.
-
+ --
-- In the example above, the call to B is safe as long as the call to
-- A is safe. There are several cases to consider:
-
+ --
-- <call 1 to A>
-- function B ...;
-
+ --
-- <call 2 to A>
-- function A ... is
-- begin
-- return B;
-- ...
-- end A;
-
+ --
-- <call 3 to A>
-- function B ... is
-- ...
-- end B;
-
+ --
-- * Call 1 - This call is either nested within some scenario or not,
-- which falls under the two general cases outlined above.
-
+ --
-- * Call 2 - This is the same case as Call 1.
-
+ --
-- * Call 3 - The placement of this call limits the range of B's
-- early call region unto call 3, therefore the call to B is no
-- longer within the early call region of B's body, making it ABE-
-- initial condition context because this leads to incorrect
-- diagnostics.
- if In_Init_Cond then
+ if State.Within_Initial_Condition then
null;
-- Do not emit any ABE diagnostics when the call occurs in a
-- partial finalization context because this leads to confusing
-- noise.
- elsif In_Partial_Fin then
+ elsif State.Within_Partial_Finalization then
null;
-- ABE diagnostics are emitted only in the static model because
else
Ensure_Prior_Elaboration
- (N => Call,
- Unit_Id => Target_Attrs.Unit_Id,
- Prag_Nam => Name_Elaborate_All,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (N => Call,
+ Unit_Id => Target_Attrs.Unit_Id,
+ Prag_Nam => Name_Elaborate_All,
+ State => State);
end if;
end Process_Conditional_ABE_Call_SPARK;
-------------------------------------------
procedure Process_Conditional_ABE_Instantiation
- (Exp_Inst : Node_Id;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Exp_Inst : Node_Id;
+ State : Processing_Attributes)
is
Gen_Attrs : Target_Attributes;
Gen_Id : Entity_Id;
-- Nothing to do when the root scenario appears at the declaration level
-- and the generic is in the same unit, but outside this context.
-
+ --
-- generic
-- procedure Gen is ...; -- generic declaration
-
+ --
-- procedure Proc is
-- function A ... is
-- begin
-- ...
-- ...
-- end A;
-
+ --
-- X : ... := A; -- root scenario
-- ...
-
+ --
-- procedure Gen is
-- ...
-- end Gen;
-
+ --
-- In the example above, the context of X is the declarative region of
-- Proc. The "elaboration" of X may eventually reach Gen which appears
-- outside of X's context. Gen is relevant only when Proc is invoked,
elsif SPARK_Rules_On then
Process_Conditional_ABE_Instantiation_SPARK
- (Inst => Inst,
- Gen_Id => Gen_Id,
- Gen_Attrs => Gen_Attrs,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (Inst => Inst,
+ Gen_Id => Gen_Id,
+ Gen_Attrs => Gen_Attrs,
+ State => State);
-- Otherwise the Ada rules are in effect, or SPARK code is allowed to
-- violate the SPARK rules.
else
Process_Conditional_ABE_Instantiation_Ada
- (Exp_Inst => Exp_Inst,
- Inst => Inst,
- Inst_Attrs => Inst_Attrs,
- Gen_Id => Gen_Id,
- Gen_Attrs => Gen_Attrs,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (Exp_Inst => Exp_Inst,
+ Inst => Inst,
+ Inst_Attrs => Inst_Attrs,
+ Gen_Id => Gen_Id,
+ Gen_Attrs => Gen_Attrs,
+ State => State);
end if;
end Process_Conditional_ABE_Instantiation;
-----------------------------------------------
procedure Process_Conditional_ABE_Instantiation_Ada
- (Exp_Inst : Node_Id;
- Inst : Node_Id;
- Inst_Attrs : Instantiation_Attributes;
- Gen_Id : Entity_Id;
- Gen_Attrs : Target_Attributes;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Exp_Inst : Node_Id;
+ Inst : Node_Id;
+ Inst_Attrs : Instantiation_Attributes;
+ Gen_Id : Entity_Id;
+ Gen_Attrs : Target_Attributes;
+ State : Processing_Attributes)
is
Check_OK : constant Boolean :=
not Inst_Attrs.Ghost_Mode_Ignore
-- the generic have active elaboration checks and both are not ignored
-- Ghost constructs.
+ New_State : Processing_Attributes := State;
+ -- Each step of the Processing phase constitutes a new state
+
Root : constant Node_Id := Root_Scenario;
begin
-- Nothing to do when the instantiation is ABE-safe
-
+ --
-- generic
-- package Gen is
-- ...
-- end Gen;
-
+ --
-- package body Gen is
-- ...
-- end Gen;
-
+ --
-- with Gen;
-- procedure Main is
-- package Inst is new Gen (ABE); -- safe instantiation
then
-- If the root scenario appears prior to the generic body, then this
-- is a possible ABE with respect to the root scenario.
-
+ --
-- generic
-- package Gen is
-- ...
-- end Gen;
-
+ --
-- function A ... is
-- begin
-- if Some_Condition then
-- package Inst is new Gen; -- instantiation site
-- ...
-- end A;
-
+ --
-- X : ... := A; -- root scenario
-
+ --
-- package body Gen is -- generic body
-- ...
-- end Gen;
-
+ --
-- Y : ... := A; -- root scenario
-
+ --
-- IMPORTANT: The instantiation of Gen is a possible ABE for X, but
-- not for Y. Installing an unconditional ABE raise prior to the
-- instance site would be wrong as it will fail for Y as well, but in
-- in partial finalization context because this leads to unwanted
-- noise.
- if In_Partial_Fin then
+ if State.Within_Partial_Finalization then
null;
-- ABE diagnostics are emitted only in the static model because
Target_Id => Gen_Attrs.Spec_Id,
Target_Decl => Gen_Attrs.Spec_Decl,
Target_Body => Gen_Attrs.Body_Decl);
+
+ -- Update the state of the Processing phase to indicate that
+ -- no implicit Elaborate[_All] pragmas must be generated from
+ -- this point on.
+ --
+ -- generic
+ -- package Gen is
+ -- ...
+ -- end Gen;
+ --
+ -- function A ... is
+ -- begin
+ -- if Some_Condition then
+ -- <ABE check>
+ -- declare Inst is new Gen;
+ -- ...
+ -- end A;
+ --
+ -- X : ... := A;
+ --
+ -- package body Gen is
+ -- begin
+ -- External.Subp; -- imparts Elaborate_All
+ -- end Gen;
+ --
+ -- If Some_Condition is True, then the ABE check will fail at
+ -- runtime and the call to External.Subp will never take place,
+ -- rendering the implicit Elaborate_All useless.
+ --
+ -- If Some_Condition is False, then the call to External.Subp
+ -- will never take place, rendering the implicit Elaborate_All
+ -- useless.
+
+ New_State.Suppress_Implicit_Pragmas := True;
end if;
end if;
end if;
-- Ensure that the unit with the generic body is elaborated prior to
- -- the main unit. No implicit pragma Elaborate is generated if the
- -- instantiation has elaboration checks suppressed. This behaviour
- -- parallels that of the old ABE mechanism.
+ -- the main unit. No implicit pragma is generated if the instantiation
+ -- has elaboration checks suppressed. This behaviour parallels that of
+ -- the old ABE mechanism.
if Inst_Attrs.Elab_Checks_OK then
Ensure_Prior_Elaboration
- (N => Inst,
- Unit_Id => Gen_Attrs.Unit_Id,
- Prag_Nam => Name_Elaborate,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (N => Inst,
+ Unit_Id => Gen_Attrs.Unit_Id,
+ Prag_Nam => Name_Elaborate,
+ State => New_State);
end if;
end Process_Conditional_ABE_Instantiation_Ada;
-------------------------------------------------
procedure Process_Conditional_ABE_Instantiation_SPARK
- (Inst : Node_Id;
- Gen_Id : Entity_Id;
- Gen_Attrs : Target_Attributes;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Inst : Node_Id;
+ Gen_Id : Entity_Id;
+ Gen_Attrs : Target_Attributes;
+ State : Processing_Attributes)
is
Req_Nam : Name_Id;
else
Ensure_Prior_Elaboration
- (N => Inst,
- Unit_Id => Gen_Attrs.Unit_Id,
- Prag_Nam => Name_Elaborate,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (N => Inst,
+ Unit_Id => Gen_Attrs.Unit_Id,
+ Prag_Nam => Name_Elaborate,
+ State => State);
end if;
end Process_Conditional_ABE_Instantiation_SPARK;
-- Placing the body in alphabetical order will result in a guaranteed ABE.
procedure Process_Conditional_ABE
- (N : Node_Id;
- In_Init_Cond : Boolean := False;
- In_Partial_Fin : Boolean := False;
- In_Task_Body : Boolean := False)
+ (N : Node_Id;
+ State : Processing_Attributes := Initial_State)
is
Call_Attrs : Call_Attributes;
Target_Id : Entity_Id;
if Is_Suitable_Access (N) then
Process_Conditional_ABE_Access
- (Attr => N,
- In_Init_Cond => In_Init_Cond,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (Attr => N,
+ State => State);
- -- Calls
+ -- Activations and calls
elsif Is_Suitable_Call (N) then
if Is_Activation_Proc (Target_Id) then
Process_Conditional_ABE_Activation
- (Call => N,
- Call_Attrs => Call_Attrs,
- In_Init_Cond => In_Init_Cond,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (Call => N,
+ Call_Attrs => Call_Attrs,
+ State => State);
else
Process_Conditional_ABE_Call
- (Call => N,
- Call_Attrs => Call_Attrs,
- Target_Id => Target_Id,
- In_Init_Cond => In_Init_Cond,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (Call => N,
+ Call_Attrs => Call_Attrs,
+ Target_Id => Target_Id,
+ State => State);
end if;
end if;
elsif Is_Suitable_Instantiation (N) then
Process_Conditional_ABE_Instantiation
- (Exp_Inst => N,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (Exp_Inst => N,
+ State => State);
-- Variable assignments
--------------------------------------------
procedure Process_Guaranteed_ABE_Activation_Impl
- (Call : Node_Id;
- Call_Attrs : Call_Attributes;
- Obj_Id : Entity_Id;
- Task_Attrs : Task_Attributes;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
+ (Call : Node_Id;
+ Call_Attrs : Call_Attributes;
+ Obj_Id : Entity_Id;
+ Task_Attrs : Task_Attributes;
+ State : Processing_Attributes)
is
- pragma Unreferenced (In_Init_Cond);
- pragma Unreferenced (In_Partial_Fin);
- pragma Unreferenced (In_Task_Body);
+ pragma Unreferenced (State);
Check_OK : constant Boolean :=
not Is_Ignored_Ghost_Entity (Obj_Id)
begin
-- Nothing to do when the root scenario appears at the declaration
-- level and the task is in the same unit, but outside this context.
-
+ --
-- task type Task_Typ; -- task declaration
-
+ --
-- procedure Proc is
-- function A ... is
-- begin
-- end;
-- ...
-- end A;
-
+ --
-- X : ... := A; -- root scenario
-- ...
-
+ --
-- task body Task_Typ is
-- ...
-- end Task_Typ;
-
+ --
-- In the example above, the context of X is the declarative list of
-- Proc. The "elaboration" of X may reach the activation of T whose body
-- is defined outside of X's context. The task body is relevant only
return;
-- Nothing to do when the activation is ABE-safe
-
+ --
-- generic
-- package Gen is
-- task type Task_Typ;
-- end Gen;
-
+ --
-- package body Gen is
-- task body Task_Typ is
-- begin
-- ...
-- end Task_Typ;
-- end Gen;
-
+ --
-- with Gen;
-- procedure Main is
-- package Nested is
- -- ...
- -- end Nested;
-
- -- package body Nested is
-- package Inst is new Gen;
-- T : Inst.Task_Typ;
- -- [begin]
- -- <activation call> -- safe activation
- -- end Nested;
+ -- end Nested; -- safe activation
-- ...
elsif Is_Safe_Activation (Call, Task_Attrs.Task_Decl) then
-- call and the task appear within the same context ignoring library
-- levels, and the body of the task has not been seen yet or appears
-- after the activation call.
-
+ --
-- procedure Guaranteed_ABE is
-- task type Task_Typ;
-
+ --
-- package Nested is
- -- ...
- -- end Nested;
-
- -- package body Nested is
-- T : Task_Typ;
- -- [begin]
-- <activation call> -- guaranteed ABE
-- end Nested;
-
+ --
-- task body Task_Typ is
-- ...
-- end Task_Typ;
-- Nothing to do when the root scenario appears at the declaration level
-- and the target is in the same unit, but outside this context.
-
+ --
-- function B ...; -- target declaration
-
+ --
-- procedure Proc is
-- function A ... is
-- begin
-- return B; -- call site
-- ...
-- end A;
-
+ --
-- X : ... := A; -- root scenario
-- ...
-
+ --
-- function B ... is
-- ...
-- end B;
-
+ --
-- In the example above, the context of X is the declarative region of
-- Proc. The "elaboration" of X may eventually reach B which is defined
-- outside of X's context. B is relevant only when Proc is invoked, but
return;
-- Nothing to do when the call is ABE-safe
-
+ --
-- generic
-- function Gen ...;
-
+ --
-- function Gen ... is
-- begin
-- ...
-- end Gen;
-
+ --
-- with Gen;
-- procedure Main is
-- function Inst is new Gen;
-- A call leads to a guaranteed ABE when the call and the target appear
-- within the same context ignoring library levels, and the body of the
-- target has not been seen yet or appears after the call.
-
+ --
-- procedure Guaranteed_ABE is
-- function Func ...;
-
+ --
-- package Nested is
-- Obj : ... := Func; -- guaranteed ABE
-- end Nested;
-
+ --
-- function Func ... is
-- ...
-- end Func;
-- Nothing to do when the root scenario appears at the declaration level
-- and the generic is in the same unit, but outside this context.
-
+ --
-- generic
-- procedure Gen is ...; -- generic declaration
-
+ --
-- procedure Proc is
-- function A ... is
-- begin
-- ...
-- ...
-- end A;
-
+ --
-- X : ... := A; -- root scenario
-- ...
-
+ --
-- procedure Gen is
-- ...
-- end Gen;
-
+ --
-- In the example above, the context of X is the declarative region of
-- Proc. The "elaboration" of X may eventually reach Gen which appears
-- outside of X's context. Gen is relevant only when Proc is invoked,
return;
-- Nothing to do when the instantiation is ABE-safe
-
+ --
-- generic
-- package Gen is
-- ...
-- end Gen;
-
+ --
-- package body Gen is
-- ...
-- end Gen;
-
+ --
-- with Gen;
-- procedure Main is
-- package Inst is new Gen (ABE); -- safe instantiation
-- the generic appear within the same context ignoring library levels,
-- and the body of the generic has not been seen yet or appears after
-- the instantiation.
-
+ --
-- procedure Guaranteed_ABE is
-- generic
-- procedure Gen;
-
+ --
-- package Nested is
-- procedure Inst is new Gen; -- guaranteed ABE
-- end Nested;
-
+ --
-- procedure Gen is
-- ...
-- end Gen;
if Is_Activation_Proc (Target_Id) then
Process_Guaranteed_ABE_Activation
- (Call => N,
- Call_Attrs => Call_Attrs,
- In_Init_Cond => False,
- In_Partial_Fin => False,
- In_Task_Body => False);
+ (Call => N,
+ Call_Attrs => Call_Attrs,
+ State => Initial_State);
else
Process_Guaranteed_ABE_Call
Declaration_Level_OK := False;
Library_Level_OK := False;
+ -- Nothing to do when switch -gnatH (legacy elaboration checking mode
+ -- enabled) is in effect because the legacy ABE mechanism does not need
+ -- to carry out this action.
+
+ if Legacy_Elaboration_Checks then
+ return;
+
-- Nothing to do for ASIS. As a result, no ABE checks and diagnostics
-- are performed in this mode.
- if ASIS_Mode then
+ elsif ASIS_Mode then
return;
-- Nothing to do when the scenario is being preanalyzed
if Declaration_Level_OK and then Level = Declaration_Level then
null;
- -- Library-level scenario
+ -- Library-level or instantiation scenario
elsif Library_Level_OK
and then Level in Library_Or_Instantiation_Level
-- Traverse_Body --
-------------------
- procedure Traverse_Body
- (N : Node_Id;
- In_Init_Cond : Boolean;
- In_Partial_Fin : Boolean;
- In_Task_Body : Boolean)
- is
+ procedure Traverse_Body (N : Node_Id; State : Processing_Attributes) is
procedure Find_And_Process_Nested_Scenarios;
pragma Inline (Find_And_Process_Nested_Scenarios);
-- Examine the declarations and statements of subprogram body N for
elsif Nkind_In (Original_Node (Nod), N_Accept_Statement,
N_Selective_Accept)
- and then Restriction_Active (No_Entry_Calls_In_Elaboration_Code)
then
- return Abandon;
+ if Restriction_Active (No_Entry_Calls_In_Elaboration_Code) then
+ return Abandon;
+
+ -- The same behavior is achieved when switch -gnatd_a (stop
+ -- elabortion checks on accept or select statement) is in
+ -- effect.
+
+ elsif Debug_Flag_Underscore_A then
+ return Abandon;
+ end if;
-- Certain nodes carry semantic lists which act as repositories
-- until expansion transforms the node and relocates the contents.
Save_Scenario (Nod);
Process_Conditional_ABE
- (N => Nod,
- In_Init_Cond => In_Init_Cond,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (N => Nod,
+ State => State);
end if;
return OK;
Nested_Elmt := First_Elmt (Nested);
while Present (Nested_Elmt) loop
Process_Conditional_ABE
- (N => Node (Nested_Elmt),
- In_Init_Cond => In_Init_Cond,
- In_Partial_Fin => In_Partial_Fin,
- In_Task_Body => In_Task_Body);
+ (N => Node (Nested_Elmt),
+ State => State);
Next_Elmt (Nested_Elmt);
end loop;
return Visited_Bodies_Index (Key mod Visited_Bodies_Max);
end Visited_Bodies_Hash;
+ ---------------------------------------------------------------------------
+ -- --
+ -- L E G A C Y A C C E S S B E F O R E E L A B O R A T I O N --
+ -- --
+ -- M E C H A N I S M --
+ -- --
+ ---------------------------------------------------------------------------
+
+ -- This section contains the implementation of the pre-18.x legacy ABE
+ -- mechanism. The mechanism can be activated using switch -gnatH (legacy
+ -- elaboration checking mode enabled).
+
+ -----------------------------
+ -- Description of Approach --
+ -----------------------------
+
+ -- Every non-static call that is encountered by Sem_Res results in a call
+ -- to Check_Elab_Call, with N being the call node, and Outer set to its
+ -- default value of True. In addition X'Access is treated like a call
+ -- for the access-to-procedure case, and in SPARK mode only we also
+ -- check variable references.
+
+ -- The goal of Check_Elab_Call is to determine whether or not the reference
+ -- in question can generate an access before elaboration error (raising
+ -- Program_Error) either by directly calling a subprogram whose body
+ -- has not yet been elaborated, or indirectly, by calling a subprogram
+ -- whose body has been elaborated, but which contains a call to such a
+ -- subprogram.
+
+ -- In addition, in SPARK mode, we are checking for a variable reference in
+ -- another package, which requires an explicit Elaborate_All pragma.
+
+ -- The only references that we need to look at the outer level are
+ -- references that occur in elaboration code. There are two cases. The
+ -- reference can be at the outer level of elaboration code, or it can
+ -- be within another unit, e.g. the elaboration code of a subprogram.
+
+ -- In the case of an elaboration call at the outer level, we must trace
+ -- all calls to outer level routines either within the current unit or to
+ -- other units that are with'ed. For calls within the current unit, we can
+ -- determine if the body has been elaborated or not, and if it has not,
+ -- then a warning is generated.
+
+ -- Note that there are two subcases. If the original call directly calls a
+ -- subprogram whose body has not been elaborated, then we know that an ABE
+ -- will take place, and we replace the call by a raise of Program_Error.
+ -- If the call is indirect, then we don't know that the PE will be raised,
+ -- since the call might be guarded by a conditional. In this case we set
+ -- Do_Elab_Check on the call so that a dynamic check is generated, and
+ -- output a warning.
+
+ -- For calls to a subprogram in a with'ed unit or a 'Access or variable
+ -- reference (SPARK mode case), we require that a pragma Elaborate_All
+ -- or pragma Elaborate be present, or that the referenced unit have a
+ -- pragma Preelaborate, pragma Pure, or pragma Elaborate_Body. If none
+ -- of these conditions is met, then a warning is generated that a pragma
+ -- Elaborate_All may be needed (error in the SPARK case), or an implicit
+ -- pragma is generated.
+
+ -- For the case of an elaboration call at some inner level, we are
+ -- interested in tracing only calls to subprograms at the same level, i.e.
+ -- those that can be called during elaboration. Any calls to outer level
+ -- routines cannot cause ABE's as a result of the original call (there
+ -- might be an outer level call to the subprogram from outside that causes
+ -- the ABE, but that gets analyzed separately).
+
+ -- Note that we never trace calls to inner level subprograms, since these
+ -- cannot result in ABE's unless there is an elaboration problem at a lower
+ -- level, which will be separately detected.
+
+ -- Note on pragma Elaborate. The checking here assumes that a pragma
+ -- Elaborate on a with'ed unit guarantees that subprograms within the unit
+ -- can be called without causing an ABE. This is not in fact the case since
+ -- pragma Elaborate does not guarantee the transitive coverage guaranteed
+ -- by Elaborate_All. However, we decide to trust the user in this case.
+
+ --------------------------------------
+ -- Instantiation Elaboration Errors --
+ --------------------------------------
+
+ -- A special case arises when an instantiation appears in a context that is
+ -- known to be before the body is elaborated, e.g.
+
+ -- generic package x is ...
+ -- ...
+ -- package xx is new x;
+ -- ...
+ -- package body x is ...
+
+ -- In this situation it is certain that an elaboration error will occur,
+ -- and an unconditional raise Program_Error statement is inserted before
+ -- the instantiation, and a warning generated.
+
+ -- The problem is that in this case we have no place to put the body of
+ -- the instantiation. We can't put it in the normal place, because it is
+ -- too early, and will cause errors to occur as a result of referencing
+ -- entities before they are declared.
+
+ -- Our approach in this case is simply to avoid creating the body of the
+ -- instantiation in such a case. The instantiation spec is modified to
+ -- include dummy bodies for all subprograms, so that the resulting code
+ -- does not contain subprogram specs with no corresponding bodies.
+
+ -- The following table records the recursive call chain for output in the
+ -- Output routine. Each entry records the call node and the entity of the
+ -- called routine. The number of entries in the table (i.e. the value of
+ -- Elab_Call.Last) indicates the current depth of recursion and is used to
+ -- identify the outer level.
+
+ type Elab_Call_Element is record
+ Cloc : Source_Ptr;
+ Ent : Entity_Id;
+ end record;
+
+ package Elab_Call is new Table.Table
+ (Table_Component_Type => Elab_Call_Element,
+ Table_Index_Type => Int,
+ Table_Low_Bound => 1,
+ Table_Initial => 50,
+ Table_Increment => 100,
+ Table_Name => "Elab_Call");
+
+ -- The following table records all calls that have been processed starting
+ -- from an outer level call. The table prevents both infinite recursion and
+ -- useless reanalysis of calls within the same context. The use of context
+ -- is important because it allows for proper checks in more complex code:
+
+ -- if ... then
+ -- Call; -- requires a check
+ -- Call; -- does not need a check thanks to the table
+ -- elsif ... then
+ -- Call; -- requires a check, different context
+ -- end if;
+
+ -- Call; -- requires a check, different context
+
+ type Visited_Element is record
+ Subp_Id : Entity_Id;
+ -- The entity of the subprogram being called
+
+ Context : Node_Id;
+ -- The context where the call to the subprogram occurs
+ end record;
+
+ package Elab_Visited is new Table.Table
+ (Table_Component_Type => Visited_Element,
+ Table_Index_Type => Int,
+ Table_Low_Bound => 1,
+ Table_Initial => 200,
+ Table_Increment => 100,
+ Table_Name => "Elab_Visited");
+
+ -- The following table records delayed calls which must be examined after
+ -- all generic bodies have been instantiated.
+
+ type Delay_Element is record
+ N : Node_Id;
+ -- The parameter N from the call to Check_Internal_Call. Note that this
+ -- node may get rewritten over the delay period by expansion in the call
+ -- case (but not in the instantiation case).
+
+ E : Entity_Id;
+ -- The parameter E from the call to Check_Internal_Call
+
+ Orig_Ent : Entity_Id;
+ -- The parameter Orig_Ent from the call to Check_Internal_Call
+
+ Curscop : Entity_Id;
+ -- The current scope of the call. This is restored when we complete the
+ -- delayed call, so that we do this in the right scope.
+
+ Outer_Scope : Entity_Id;
+ -- Save scope of outer level call
+
+ From_Elab_Code : Boolean;
+ -- Save indication of whether this call is from elaboration code
+
+ In_Task_Activation : Boolean;
+ -- Save indication of whether this call is from a task body. Tasks are
+ -- activated at the "begin", which is after all local procedure bodies,
+ -- so calls to those procedures can't fail, even if they occur after the
+ -- task body.
+
+ From_SPARK_Code : Boolean;
+ -- Save indication of whether this call is under SPARK_Mode => On
+ end record;
+
+ package Delay_Check is new Table.Table
+ (Table_Component_Type => Delay_Element,
+ Table_Index_Type => Int,
+ Table_Low_Bound => 1,
+ Table_Initial => 1000,
+ Table_Increment => 100,
+ Table_Name => "Delay_Check");
+
+ C_Scope : Entity_Id;
+ -- Top-level scope of current scope. Compute this only once at the outer
+ -- level, i.e. for a call to Check_Elab_Call from outside this unit.
+
+ Outer_Level_Sloc : Source_Ptr;
+ -- Save Sloc value for outer level call node for comparisons of source
+ -- locations. A body is too late if it appears after the *outer* level
+ -- call, not the particular call that is being analyzed.
+
+ From_Elab_Code : Boolean;
+ -- This flag shows whether the outer level call currently being examined
+ -- is or is not in elaboration code. We are only interested in calls to
+ -- routines in other units if this flag is True.
+
+ In_Task_Activation : Boolean := False;
+ -- This flag indicates whether we are performing elaboration checks on task
+ -- bodies, at the point of activation. If true, we do not raise
+ -- Program_Error for calls to local procedures, because all local bodies
+ -- are known to be elaborated. However, we still need to trace such calls,
+ -- because a local procedure could call a procedure in another package,
+ -- so we might need an implicit Elaborate_All.
+
+ Delaying_Elab_Checks : Boolean := True;
+ -- This is set True till the compilation is complete, including the
+ -- insertion of all instance bodies. Then when Check_Elab_Calls is called,
+ -- the delay table is used to make the delayed calls and this flag is reset
+ -- to False, so that the calls are processed.
+
+ -----------------------
+ -- Local Subprograms --
+ -----------------------
+
+ -- Note: Outer_Scope in all following specs represents the scope of
+ -- interest of the outer level call. If it is set to Standard_Standard,
+ -- then it means the outer level call was at elaboration level, and that
+ -- thus all calls are of interest. If it was set to some other scope,
+ -- then the original call was an inner call, and we are not interested
+ -- in calls that go outside this scope.
+
+ procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id);
+ -- Analysis of construct N shows that we should set Elaborate_All_Desirable
+ -- for the WITH clause for unit U (which will always be present). A special
+ -- case is when N is a function or procedure instantiation, in which case
+ -- it is sufficient to set Elaborate_Desirable, since in this case there is
+ -- no possibility of transitive elaboration issues.
+
+ procedure Check_A_Call
+ (N : Node_Id;
+ E : Entity_Id;
+ Outer_Scope : Entity_Id;
+ Inter_Unit_Only : Boolean;
+ Generate_Warnings : Boolean := True;
+ In_Init_Proc : Boolean := False);
+ -- This is the internal recursive routine that is called to check for
+ -- possible elaboration error. The argument N is a subprogram call or
+ -- generic instantiation, or 'Access attribute reference to be checked, and
+ -- E is the entity of the called subprogram, or instantiated generic unit,
+ -- or subprogram referenced by 'Access.
+ --
+ -- In SPARK mode, N can also be a variable reference, since in SPARK this
+ -- also triggers a requirement for Elaborate_All, and in this case E is the
+ -- entity being referenced.
+ --
+ -- Outer_Scope is the outer level scope for the original reference.
+ -- Inter_Unit_Only is set if the call is only to be checked in the
+ -- case where it is to another unit (and skipped if within a unit).
+ -- Generate_Warnings is set to False to suppress warning messages about
+ -- missing pragma Elaborate_All's. These messages are not wanted for
+ -- inner calls in the dynamic model. Note that an instance of the Access
+ -- attribute applied to a subprogram also generates a call to this
+ -- procedure (since the referenced subprogram may be called later
+ -- indirectly). Flag In_Init_Proc should be set whenever the current
+ -- context is a type init proc.
+ --
+ -- Note: this might better be called Check_A_Reference to recognize the
+ -- variable case for SPARK, but we prefer to retain the historical name
+ -- since in practice this is mostly about checking calls for the possible
+ -- occurrence of an access-before-elaboration exception.
+
+ procedure Check_Bad_Instantiation (N : Node_Id);
+ -- N is a node for an instantiation (if called with any other node kind,
+ -- Check_Bad_Instantiation ignores the call). This subprogram checks for
+ -- the special case of a generic instantiation of a generic spec in the
+ -- same declarative part as the instantiation where a body is present and
+ -- has not yet been seen. This is an obvious error, but needs to be checked
+ -- specially at the time of the instantiation, since it is a case where we
+ -- cannot insert the body anywhere. If this case is detected, warnings are
+ -- generated, and a raise of Program_Error is inserted. In addition any
+ -- subprograms in the generic spec are stubbed, and the Bad_Instantiation
+ -- flag is set on the instantiation node. The caller in Sem_Ch12 uses this
+ -- flag as an indication that no attempt should be made to insert an
+ -- instance body.
+
+ procedure Check_Internal_Call
+ (N : Node_Id;
+ E : Entity_Id;
+ Outer_Scope : Entity_Id;
+ Orig_Ent : Entity_Id);
+ -- N is a function call or procedure statement call node and E is the
+ -- entity of the called function, which is within the current compilation
+ -- unit (where subunits count as part of the parent). This call checks if
+ -- this call, or any call within any accessed body could cause an ABE, and
+ -- if so, outputs a warning. Orig_Ent differs from E only in the case of
+ -- renamings, and points to the original name of the entity. This is used
+ -- for error messages. Outer_Scope is the outer level scope for the
+ -- original call.
+
+ procedure Check_Internal_Call_Continue
+ (N : Node_Id;
+ E : Entity_Id;
+ Outer_Scope : Entity_Id;
+ Orig_Ent : Entity_Id);
+ -- The processing for Check_Internal_Call is divided up into two phases,
+ -- and this represents the second phase. The second phase is delayed if
+ -- Delaying_Elab_Checks is set to True. In this delayed case, the first
+ -- phase makes an entry in the Delay_Check table, which is processed when
+ -- Check_Elab_Calls is called. N, E and Orig_Ent are as for the call to
+ -- Check_Internal_Call. Outer_Scope is the outer level scope for the
+ -- original call.
+
+ function Get_Referenced_Ent (N : Node_Id) return Entity_Id;
+ -- N is either a function or procedure call or an access attribute that
+ -- references a subprogram. This call retrieves the relevant entity. If
+ -- this is a call to a protected subprogram, the entity is a selected
+ -- component. The callable entity may be absent, in which case Empty is
+ -- returned. This happens with non-analyzed calls in nested generics.
+ --
+ -- If SPARK_Mode is On, then N can also be a reference to an E_Variable
+ -- entity, in which case, the value returned is simply this entity.
+
+ function Has_Generic_Body (N : Node_Id) return Boolean;
+ -- N is a generic package instantiation node, and this routine determines
+ -- if this package spec does in fact have a generic body. If so, then
+ -- True is returned, otherwise False. Note that this is not at all the
+ -- same as checking if the unit requires a body, since it deals with
+ -- the case of optional bodies accurately (i.e. if a body is optional,
+ -- then it looks to see if a body is actually present). Note: this
+ -- function can only do a fully correct job if in generating code mode
+ -- where all bodies have to be present. If we are operating in semantics
+ -- check only mode, then in some cases of optional bodies, a result of
+ -- False may incorrectly be given. In practice this simply means that
+ -- some cases of warnings for incorrect order of elaboration will only
+ -- be given when generating code, which is not a big problem (and is
+ -- inevitable, given the optional body semantics of Ada).
+
+ procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty);
+ -- Given code for an elaboration check (or unconditional raise if the check
+ -- is not needed), inserts the code in the appropriate place. N is the call
+ -- or instantiation node for which the check code is required. C is the
+ -- test whose failure triggers the raise.
+
+ function Is_Call_Of_Generic_Formal (N : Node_Id) return Boolean;
+ -- Returns True if node N is a call to a generic formal subprogram
+
+ function Is_Finalization_Procedure (Id : Entity_Id) return Boolean;
+ -- Determine whether entity Id denotes a [Deep_]Finalize procedure
+
+ procedure Output_Calls
+ (N : Node_Id;
+ Check_Elab_Flag : Boolean);
+ -- Outputs chain of calls stored in the Elab_Call table. The caller has
+ -- already generated the main warning message, so the warnings generated
+ -- are all continuation messages. The argument is the call node at which
+ -- the messages are to be placed. When Check_Elab_Flag is set, calls are
+ -- enumerated only when flag Elab_Warning is set for the dynamic case or
+ -- when flag Elab_Info_Messages is set for the static case.
+
+ function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean;
+ -- Given two scopes, determine whether they are the same scope from an
+ -- elaboration point of view, i.e. packages and blocks are ignored.
+
+ procedure Set_C_Scope;
+ -- On entry C_Scope is set to some scope. On return, C_Scope is reset
+ -- to be the enclosing compilation unit of this scope.
+
+ procedure Set_Elaboration_Constraint
+ (Call : Node_Id;
+ Subp : Entity_Id;
+ Scop : Entity_Id);
+ -- The current unit U may depend semantically on some unit P that is not
+ -- in the current context. If there is an elaboration call that reaches P,
+ -- we need to indicate that P requires an Elaborate_All, but this is not
+ -- effective in U's ali file, if there is no with_clause for P. In this
+ -- case we add the Elaborate_All on the unit Q that directly or indirectly
+ -- makes P available. This can happen in two cases:
+ --
+ -- a) Q declares a subtype of a type declared in P, and the call is an
+ -- initialization call for an object of that subtype.
+ --
+ -- b) Q declares an object of some tagged type whose root type is
+ -- declared in P, and the initialization call uses object notation on
+ -- that object to reach a primitive operation or a classwide operation
+ -- declared in P.
+ --
+ -- If P appears in the context of U, the current processing is correct.
+ -- Otherwise we must identify these two cases to retrieve Q and place the
+ -- Elaborate_All_Desirable on it.
+
+ function Spec_Entity (E : Entity_Id) return Entity_Id;
+ -- Given a compilation unit entity, if it is a spec entity, it is returned
+ -- unchanged. If it is a body entity, then the spec for the corresponding
+ -- spec is returned
+
+ function Within (E1, E2 : Entity_Id) return Boolean;
+ -- Given two scopes E1 and E2, returns True if E1 is equal to E2, or is one
+ -- of its contained scopes, False otherwise.
+
+ function Within_Elaborate_All
+ (Unit : Unit_Number_Type;
+ E : Entity_Id) return Boolean;
+ -- Return True if we are within the scope of an Elaborate_All for E, or if
+ -- we are within the scope of an Elaborate_All for some other unit U, and U
+ -- with's E. This prevents spurious warnings when the called entity is
+ -- renamed within U, or in case of generic instances.
+
+ --------------------------------------
+ -- Activate_Elaborate_All_Desirable --
+ --------------------------------------
+
+ procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id) is
+ UN : constant Unit_Number_Type := Get_Code_Unit (N);
+ CU : constant Node_Id := Cunit (UN);
+ UE : constant Entity_Id := Cunit_Entity (UN);
+ Unm : constant Unit_Name_Type := Unit_Name (UN);
+ CI : constant List_Id := Context_Items (CU);
+ Itm : Node_Id;
+ Ent : Entity_Id;
+
+ procedure Add_To_Context_And_Mark (Itm : Node_Id);
+ -- This procedure is called when the elaborate indication must be
+ -- applied to a unit not in the context of the referencing unit. The
+ -- unit gets added to the context as an implicit with.
+
+ function In_Withs_Of (UEs : Entity_Id) return Boolean;
+ -- UEs is the spec entity of a unit. If the unit to be marked is
+ -- in the context item list of this unit spec, then the call returns
+ -- True and Itm is left set to point to the relevant N_With_Clause node.
+
+ procedure Set_Elab_Flag (Itm : Node_Id);
+ -- Sets Elaborate_[All_]Desirable as appropriate on Itm
+
+ -----------------------------
+ -- Add_To_Context_And_Mark --
+ -----------------------------
+
+ procedure Add_To_Context_And_Mark (Itm : Node_Id) is
+ CW : constant Node_Id :=
+ Make_With_Clause (Sloc (Itm),
+ Name => Name (Itm));
+
+ begin
+ Set_Library_Unit (CW, Library_Unit (Itm));
+ Set_Implicit_With (CW, True);
+
+ -- Set elaborate all desirable on copy and then append the copy to
+ -- the list of body with's and we are done.
+
+ Set_Elab_Flag (CW);
+ Append_To (CI, CW);
+ end Add_To_Context_And_Mark;
+
+ -----------------
+ -- In_Withs_Of --
+ -----------------
+
+ function In_Withs_Of (UEs : Entity_Id) return Boolean is
+ UNs : constant Unit_Number_Type := Get_Source_Unit (UEs);
+ CUs : constant Node_Id := Cunit (UNs);
+ CIs : constant List_Id := Context_Items (CUs);
+
+ begin
+ Itm := First (CIs);
+ while Present (Itm) loop
+ if Nkind (Itm) = N_With_Clause then
+ Ent :=
+ Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm)));
+
+ if U = Ent then
+ return True;
+ end if;
+ end if;
+
+ Next (Itm);
+ end loop;
+
+ return False;
+ end In_Withs_Of;
+
+ -------------------
+ -- Set_Elab_Flag --
+ -------------------
+
+ procedure Set_Elab_Flag (Itm : Node_Id) is
+ begin
+ if Nkind (N) in N_Subprogram_Instantiation then
+ Set_Elaborate_Desirable (Itm);
+ else
+ Set_Elaborate_All_Desirable (Itm);
+ end if;
+ end Set_Elab_Flag;
+
+ -- Start of processing for Activate_Elaborate_All_Desirable
+
+ begin
+ -- Do not set binder indication if expansion is disabled, as when
+ -- compiling a generic unit.
+
+ if not Expander_Active then
+ return;
+ end if;
+
+ -- If an instance of a generic package contains a controlled object (so
+ -- we're calling Initialize at elaboration time), and the instance is in
+ -- a package body P that says "with P;", then we need to return without
+ -- adding "pragma Elaborate_All (P);" to P.
+
+ if U = Main_Unit_Entity then
+ return;
+ end if;
+
+ Itm := First (CI);
+ while Present (Itm) loop
+ if Nkind (Itm) = N_With_Clause then
+ Ent := Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm)));
+
+ -- If we find it, then mark elaborate all desirable and return
+
+ if U = Ent then
+ Set_Elab_Flag (Itm);
+ return;
+ end if;
+ end if;
+
+ Next (Itm);
+ end loop;
+
+ -- If we fall through then the with clause is not present in the
+ -- current unit. One legitimate possibility is that the with clause
+ -- is present in the spec when we are a body.
+
+ if Is_Body_Name (Unm)
+ and then In_Withs_Of (Spec_Entity (UE))
+ then
+ Add_To_Context_And_Mark (Itm);
+ return;
+ end if;
+
+ -- Similarly, we may be in the spec or body of a child unit, where
+ -- the unit in question is with'ed by some ancestor of the child unit.
+
+ if Is_Child_Name (Unm) then
+ declare
+ Pkg : Entity_Id;
+
+ begin
+ Pkg := UE;
+ loop
+ Pkg := Scope (Pkg);
+ exit when Pkg = Standard_Standard;
+
+ if In_Withs_Of (Pkg) then
+ Add_To_Context_And_Mark (Itm);
+ return;
+ end if;
+ end loop;
+ end;
+ end if;
+
+ -- Here if we do not find with clause on spec or body. We just ignore
+ -- this case; it means that the elaboration involves some other unit
+ -- than the unit being compiled, and will be caught elsewhere.
+ end Activate_Elaborate_All_Desirable;
+
+ ------------------
+ -- Check_A_Call --
+ ------------------
+
+ procedure Check_A_Call
+ (N : Node_Id;
+ E : Entity_Id;
+ Outer_Scope : Entity_Id;
+ Inter_Unit_Only : Boolean;
+ Generate_Warnings : Boolean := True;
+ In_Init_Proc : Boolean := False)
+ is
+ Access_Case : constant Boolean := Nkind (N) = N_Attribute_Reference;
+ -- Indicates if we have Access attribute case
+
+ function Call_To_Instance_From_Outside (Id : Entity_Id) return Boolean;
+ -- True if we're calling an instance of a generic subprogram, or a
+ -- subprogram in an instance of a generic package, and the call is
+ -- outside that instance.
+
+ procedure Elab_Warning
+ (Msg_D : String;
+ Msg_S : String;
+ Ent : Node_Or_Entity_Id);
+ -- Generate a call to Error_Msg_NE with parameters Msg_D or Msg_S (for
+ -- dynamic or static elaboration model), N and Ent. Msg_D is a real
+ -- warning (output if Msg_D is non-null and Elab_Warnings is set),
+ -- Msg_S is an info message (output if Elab_Info_Messages is set).
+
+ function Find_W_Scope return Entity_Id;
+ -- Find top-level scope for called entity (not following renamings
+ -- or derivations). This is where the Elaborate_All will go if it is
+ -- needed. We start with the called entity, except in the case of an
+ -- initialization procedure outside the current package, where the init
+ -- proc is in the root package, and we start from the entity of the name
+ -- in the call.
+
+ -----------------------------------
+ -- Call_To_Instance_From_Outside --
+ -----------------------------------
+
+ function Call_To_Instance_From_Outside (Id : Entity_Id) return Boolean is
+ Scop : Entity_Id := Id;
+
+ begin
+ loop
+ if Scop = Standard_Standard then
+ return False;
+ end if;
+
+ if Is_Generic_Instance (Scop) then
+ return not In_Open_Scopes (Scop);
+ end if;
+
+ Scop := Scope (Scop);
+ end loop;
+ end Call_To_Instance_From_Outside;
+
+ ------------------
+ -- Elab_Warning --
+ ------------------
+
+ procedure Elab_Warning
+ (Msg_D : String;
+ Msg_S : String;
+ Ent : Node_Or_Entity_Id)
+ is
+ begin
+ -- Dynamic elaboration checks, real warning
+
+ if Dynamic_Elaboration_Checks then
+ if not Access_Case then
+ if Msg_D /= "" and then Elab_Warnings then
+ Error_Msg_NE (Msg_D, N, Ent);
+ end if;
+
+ -- In the access case emit first warning message as well,
+ -- otherwise list of calls will appear as errors.
+
+ elsif Elab_Warnings then
+ Error_Msg_NE (Msg_S, N, Ent);
+ end if;
+
+ -- Static elaboration checks, info message
+
+ else
+ if Elab_Info_Messages then
+ Error_Msg_NE (Msg_S, N, Ent);
+ end if;
+ end if;
+ end Elab_Warning;
+
+ ------------------
+ -- Find_W_Scope --
+ ------------------
+
+ function Find_W_Scope return Entity_Id is
+ Refed_Ent : constant Entity_Id := Get_Referenced_Ent (N);
+ W_Scope : Entity_Id;
+
+ begin
+ if Is_Init_Proc (Refed_Ent)
+ and then not In_Same_Extended_Unit (N, Refed_Ent)
+ then
+ W_Scope := Scope (Refed_Ent);
+ else
+ W_Scope := E;
+ end if;
+
+ -- Now loop through scopes to get to the enclosing compilation unit
+
+ while not Is_Compilation_Unit (W_Scope) loop
+ W_Scope := Scope (W_Scope);
+ end loop;
+
+ return W_Scope;
+ end Find_W_Scope;
+
+ -- Local variables
+
+ Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation;
+ -- Indicates if we have instantiation case
+
+ Loc : constant Source_Ptr := Sloc (N);
+
+ Variable_Case : constant Boolean :=
+ Nkind (N) in N_Has_Entity
+ and then Present (Entity (N))
+ and then Ekind (Entity (N)) = E_Variable;
+ -- Indicates if we have variable reference case
+
+ W_Scope : constant Entity_Id := Find_W_Scope;
+ -- Top-level scope of directly called entity for subprogram. This
+ -- differs from E_Scope in the case where renamings or derivations
+ -- are involved, since it does not follow these links. W_Scope is
+ -- generally in a visible unit, and it is this scope that may require
+ -- an Elaborate_All. However, there are some cases (initialization
+ -- calls and calls involving object notation) where W_Scope might not
+ -- be in the context of the current unit, and there is an intermediate
+ -- package that is, in which case the Elaborate_All has to be placed
+ -- on this intermediate package. These special cases are handled in
+ -- Set_Elaboration_Constraint.
+
+ Ent : Entity_Id;
+ Callee_Unit_Internal : Boolean;
+ Caller_Unit_Internal : Boolean;
+ Decl : Node_Id;
+ Inst_Callee : Source_Ptr;
+ Inst_Caller : Source_Ptr;
+ Unit_Callee : Unit_Number_Type;
+ Unit_Caller : Unit_Number_Type;
+
+ Body_Acts_As_Spec : Boolean;
+ -- Set to true if call is to body acting as spec (no separate spec)
+
+ Cunit_SC : Boolean := False;
+ -- Set to suppress dynamic elaboration checks where one of the
+ -- enclosing scopes has Elaboration_Checks_Suppressed set, or else
+ -- if a pragma Elaborate[_All] applies to that scope, in which case
+ -- warnings on the scope are also suppressed. For the internal case,
+ -- we ignore this flag.
+
+ E_Scope : Entity_Id;
+ -- Top-level scope of entity for called subprogram. This value includes
+ -- following renamings and derivations, so this scope can be in a
+ -- non-visible unit. This is the scope that is to be investigated to
+ -- see whether an elaboration check is required.
+
+ Is_DIC : Boolean;
+ -- Flag set when the subprogram being invoked is the procedure generated
+ -- for pragma Default_Initial_Condition.
+
+ SPARK_Elab_Errors : Boolean;
+ -- Flag set when an entity is called or a variable is read during SPARK
+ -- dynamic elaboration.
+
+ -- Start of processing for Check_A_Call
+
+ begin
+ -- If the call is known to be within a local Suppress Elaboration
+ -- pragma, nothing to check. This can happen in task bodies. But
+ -- we ignore this for a call to a generic formal.
+
+ if Nkind (N) in N_Subprogram_Call
+ and then No_Elaboration_Check (N)
+ and then not Is_Call_Of_Generic_Formal (N)
+ then
+ return;
+
+ -- If this is a rewrite of a Valid_Scalars attribute, then nothing to
+ -- check, we don't mind in this case if the call occurs before the body
+ -- since this is all generated code.
+
+ elsif Nkind (Original_Node (N)) = N_Attribute_Reference
+ and then Attribute_Name (Original_Node (N)) = Name_Valid_Scalars
+ then
+ return;
+
+ -- Intrinsics such as instances of Unchecked_Deallocation do not have
+ -- any body, so elaboration checking is not needed, and would be wrong.
+
+ elsif Is_Intrinsic_Subprogram (E) then
+ return;
+
+ -- Do not consider references to internal variables for SPARK semantics
+
+ elsif Variable_Case and then not Comes_From_Source (E) then
+ return;
+ end if;
+
+ -- Proceed with check
+
+ Ent := E;
+
+ -- For a variable reference, just set Body_Acts_As_Spec to False
+
+ if Variable_Case then
+ Body_Acts_As_Spec := False;
+
+ -- Additional checks for all other cases
+
+ else
+ -- Go to parent for derived subprogram, or to original subprogram in
+ -- the case of a renaming (Alias covers both these cases).
+
+ loop
+ if (Suppress_Elaboration_Warnings (Ent)
+ or else Elaboration_Checks_Suppressed (Ent))
+ and then (Inst_Case or else No (Alias (Ent)))
+ then
+ return;
+ end if;
+
+ -- Nothing to do for imported entities
+
+ if Is_Imported (Ent) then
+ return;
+ end if;
+
+ exit when Inst_Case or else No (Alias (Ent));
+ Ent := Alias (Ent);
+ end loop;
+
+ Decl := Unit_Declaration_Node (Ent);
+
+ if Nkind (Decl) = N_Subprogram_Body then
+ Body_Acts_As_Spec := True;
+
+ elsif Nkind_In (Decl, N_Subprogram_Declaration,
+ N_Subprogram_Body_Stub)
+ or else Inst_Case
+ then
+ Body_Acts_As_Spec := False;
+
+ -- If we have none of an instantiation, subprogram body or subprogram
+ -- declaration, or in the SPARK case, a variable reference, then
+ -- it is not a case that we want to check. (One case is a call to a
+ -- generic formal subprogram, where we do not want the check in the
+ -- template).
+
+ else
+ return;
+ end if;
+ end if;
+
+ E_Scope := Ent;
+ loop
+ if Elaboration_Checks_Suppressed (E_Scope)
+ or else Suppress_Elaboration_Warnings (E_Scope)
+ then
+ Cunit_SC := True;
+ end if;
+
+ -- Exit when we get to compilation unit, not counting subunits
+
+ exit when Is_Compilation_Unit (E_Scope)
+ and then (Is_Child_Unit (E_Scope)
+ or else Scope (E_Scope) = Standard_Standard);
+
+ pragma Assert (E_Scope /= Standard_Standard);
+
+ -- Move up a scope looking for compilation unit
+
+ E_Scope := Scope (E_Scope);
+ end loop;
+
+ -- No checks needed for pure or preelaborated compilation units
+
+ if Is_Pure (E_Scope) or else Is_Preelaborated (E_Scope) then
+ return;
+ end if;
+
+ -- If the generic entity is within a deeper instance than we are, then
+ -- either the instantiation to which we refer itself caused an ABE, in
+ -- which case that will be handled separately, or else we know that the
+ -- body we need appears as needed at the point of the instantiation.
+ -- However, this assumption is only valid if we are in static mode.
+
+ if not Dynamic_Elaboration_Checks
+ and then
+ Instantiation_Depth (Sloc (Ent)) > Instantiation_Depth (Sloc (N))
+ then
+ return;
+ end if;
+
+ -- Do not give a warning for a package with no body
+
+ if Ekind (Ent) = E_Generic_Package and then not Has_Generic_Body (N) then
+ return;
+ end if;
+
+ -- Case of entity is in same unit as call or instantiation. In the
+ -- instantiation case, W_Scope may be different from E_Scope; we want
+ -- the unit in which the instantiation occurs, since we're analyzing
+ -- based on the expansion.
+
+ if W_Scope = C_Scope then
+ if not Inter_Unit_Only then
+ Check_Internal_Call (N, Ent, Outer_Scope, E);
+ end if;
+
+ return;
+ end if;
+
+ -- Case of entity is not in current unit (i.e. with'ed unit case)
+
+ -- We are only interested in such calls if the outer call was from
+ -- elaboration code, or if we are in Dynamic_Elaboration_Checks mode.
+
+ if not From_Elab_Code and then not Dynamic_Elaboration_Checks then
+ return;
+ end if;
+
+ -- Nothing to do if some scope said that no checks were required
+
+ if Cunit_SC then
+ return;
+ end if;
+
+ -- Nothing to do for a generic instance, because a call to an instance
+ -- cannot fail the elaboration check, because the body of the instance
+ -- is always elaborated immediately after the spec.
+
+ if Call_To_Instance_From_Outside (Ent) then
+ return;
+ end if;
+
+ -- Nothing to do if subprogram with no separate spec. However, a call
+ -- to Deep_Initialize may result in a call to a user-defined Initialize
+ -- procedure, which imposes a body dependency. This happens only if the
+ -- type is controlled and the Initialize procedure is not inherited.
+
+ if Body_Acts_As_Spec then
+ if Is_TSS (Ent, TSS_Deep_Initialize) then
+ declare
+ Typ : constant Entity_Id := Etype (First_Formal (Ent));
+ Init : Entity_Id;
+
+ begin
+ if not Is_Controlled (Typ) then
+ return;
+ else
+ Init := Find_Prim_Op (Typ, Name_Initialize);
+
+ if Comes_From_Source (Init) then
+ Ent := Init;
+ else
+ return;
+ end if;
+ end if;
+ end;
+
+ else
+ return;
+ end if;
+ end if;
+
+ -- Check cases of internal units
+
+ Callee_Unit_Internal := In_Internal_Unit (E_Scope);
+
+ -- Do not give a warning if the with'ed unit is internal and this is
+ -- the generic instantiation case (this saves a lot of hassle dealing
+ -- with the Text_IO special child units)
+
+ if Callee_Unit_Internal and Inst_Case then
+ return;
+ end if;
+
+ if C_Scope = Standard_Standard then
+ Caller_Unit_Internal := False;
+ else
+ Caller_Unit_Internal := In_Internal_Unit (C_Scope);
+ end if;
+
+ -- Do not give a warning if the with'ed unit is internal and the caller
+ -- is not internal (since the binder always elaborates internal units
+ -- first).
+
+ if Callee_Unit_Internal and not Caller_Unit_Internal then
+ return;
+ end if;
+
+ -- For now, if debug flag -gnatdE is not set, do no checking for one
+ -- internal unit withing another. This fixes the problem with the sgi
+ -- build and storage errors. To be resolved later ???
+
+ if (Callee_Unit_Internal and Caller_Unit_Internal)
+ and not Debug_Flag_EE
+ then
+ return;
+ end if;
+
+ if Is_TSS (E, TSS_Deep_Initialize) then
+ Ent := E;
+ end if;
+
+ -- If the call is in an instance, and the called entity is not
+ -- defined in the same instance, then the elaboration issue focuses
+ -- around the unit containing the template, it is this unit that
+ -- requires an Elaborate_All.
+
+ -- However, if we are doing dynamic elaboration, we need to chase the
+ -- call in the usual manner.
+
+ -- We also need to chase the call in the usual manner if it is a call
+ -- to a generic formal parameter, since that case was not handled as
+ -- part of the processing of the template.
+
+ Inst_Caller := Instantiation (Get_Source_File_Index (Sloc (N)));
+ Inst_Callee := Instantiation (Get_Source_File_Index (Sloc (Ent)));
+
+ if Inst_Caller = No_Location then
+ Unit_Caller := No_Unit;
+ else
+ Unit_Caller := Get_Source_Unit (N);
+ end if;
+
+ if Inst_Callee = No_Location then
+ Unit_Callee := No_Unit;
+ else
+ Unit_Callee := Get_Source_Unit (Ent);
+ end if;
+
+ if Unit_Caller /= No_Unit
+ and then Unit_Callee /= Unit_Caller
+ and then not Dynamic_Elaboration_Checks
+ and then not Is_Call_Of_Generic_Formal (N)
+ then
+ E_Scope := Spec_Entity (Cunit_Entity (Unit_Caller));
+
+ -- If we don't get a spec entity, just ignore call. Not quite
+ -- clear why this check is necessary. ???
+
+ if No (E_Scope) then
+ return;
+ end if;
+
+ -- Otherwise step to enclosing compilation unit
+
+ while not Is_Compilation_Unit (E_Scope) loop
+ E_Scope := Scope (E_Scope);
+ end loop;
+
+ -- For the case where N is not an instance, and is not a call within
+ -- instance to other than a generic formal, we recompute E_Scope
+ -- for the error message, since we do NOT want to go to the unit
+ -- that has the ultimate declaration in the case of renaming and
+ -- derivation and we also want to go to the generic unit in the
+ -- case of an instance, and no further.
+
+ else
+ -- Loop to carefully follow renamings and derivations one step
+ -- outside the current unit, but not further.
+
+ if not (Inst_Case or Variable_Case)
+ and then Present (Alias (Ent))
+ then
+ E_Scope := Alias (Ent);
+ else
+ E_Scope := Ent;
+ end if;
+
+ loop
+ while not Is_Compilation_Unit (E_Scope) loop
+ E_Scope := Scope (E_Scope);
+ end loop;
+
+ -- If E_Scope is the same as C_Scope, it means that there
+ -- definitely was a local renaming or derivation, and we
+ -- are not yet out of the current unit.
+
+ exit when E_Scope /= C_Scope;
+ Ent := Alias (Ent);
+ E_Scope := Ent;
+
+ -- If no alias, there could be a previous error, but not if we've
+ -- already reached the outermost level (Standard).
+
+ if No (Ent) then
+ return;
+ end if;
+ end loop;
+ end if;
+
+ if Within_Elaborate_All (Current_Sem_Unit, E_Scope) then
+ return;
+ end if;
+
+ -- Determine whether the Default_Initial_Condition procedure of some
+ -- type is being invoked.
+
+ Is_DIC := Ekind (Ent) = E_Procedure and then Is_DIC_Procedure (Ent);
+
+ -- Checks related to Default_Initial_Condition fall under the SPARK
+ -- umbrella because this is a SPARK-specific annotation.
+
+ SPARK_Elab_Errors :=
+ SPARK_Mode = On and (Is_DIC or Dynamic_Elaboration_Checks);
+
+ -- Now check if an Elaborate_All (or dynamic check) is needed
+
+ if (Elab_Info_Messages or Elab_Warnings or SPARK_Elab_Errors)
+ and then Generate_Warnings
+ and then not Suppress_Elaboration_Warnings (Ent)
+ and then not Elaboration_Checks_Suppressed (Ent)
+ and then not Suppress_Elaboration_Warnings (E_Scope)
+ and then not Elaboration_Checks_Suppressed (E_Scope)
+ then
+ -- Instantiation case
+
+ if Inst_Case then
+ if Comes_From_Source (Ent) and then SPARK_Elab_Errors then
+ Error_Msg_NE
+ ("instantiation of & during elaboration in SPARK", N, Ent);
+ else
+ Elab_Warning
+ ("instantiation of & may raise Program_Error?l?",
+ "info: instantiation of & during elaboration?$?", Ent);
+ end if;
+
+ -- Indirect call case, info message only in static elaboration
+ -- case, because the attribute reference itself cannot raise an
+ -- exception. Note that SPARK does not permit indirect calls.
+
+ elsif Access_Case then
+ Elab_Warning ("", "info: access to & during elaboration?$?", Ent);
+
+ -- Variable reference in SPARK mode
+
+ elsif Variable_Case then
+ if Comes_From_Source (Ent) and then SPARK_Elab_Errors then
+ Error_Msg_NE
+ ("reference to & during elaboration in SPARK", N, Ent);
+ end if;
+
+ -- Subprogram call case
+
+ else
+ if Nkind (Name (N)) in N_Has_Entity
+ and then Is_Init_Proc (Entity (Name (N)))
+ and then Comes_From_Source (Ent)
+ then
+ Elab_Warning
+ ("implicit call to & may raise Program_Error?l?",
+ "info: implicit call to & during elaboration?$?",
+ Ent);
+
+ elsif SPARK_Elab_Errors then
+
+ -- Emit a specialized error message when the elaboration of an
+ -- object of a private type evaluates the expression of pragma
+ -- Default_Initial_Condition. This prevents the internal name
+ -- of the procedure from appearing in the error message.
+
+ if Is_DIC then
+ Error_Msg_N
+ ("call to Default_Initial_Condition during elaboration in "
+ & "SPARK", N);
+ else
+ Error_Msg_NE
+ ("call to & during elaboration in SPARK", N, Ent);
+ end if;
+
+ else
+ Elab_Warning
+ ("call to & may raise Program_Error?l?",
+ "info: call to & during elaboration?$?",
+ Ent);
+ end if;
+ end if;
+
+ Error_Msg_Qual_Level := Nat'Last;
+
+ -- Case of Elaborate_All not present and required, for SPARK this
+ -- is an error, so give an error message.
+
+ if SPARK_Elab_Errors then
+ Error_Msg_NE -- CODEFIX
+ ("\Elaborate_All pragma required for&", N, W_Scope);
+
+ -- Otherwise we generate an implicit pragma. For a subprogram
+ -- instantiation, Elaborate is good enough, since no transitive
+ -- call is possible at elaboration time in this case.
+
+ elsif Nkind (N) in N_Subprogram_Instantiation then
+ Elab_Warning
+ ("\missing pragma Elaborate for&?l?",
+ "\implicit pragma Elaborate for& generated?$?",
+ W_Scope);
+
+ -- For all other cases, we need an implicit Elaborate_All
+
+ else
+ Elab_Warning
+ ("\missing pragma Elaborate_All for&?l?",
+ "\implicit pragma Elaborate_All for & generated?$?",
+ W_Scope);
+ end if;
+
+ Error_Msg_Qual_Level := 0;
+
+ -- Take into account the flags related to elaboration warning
+ -- messages when enumerating the various calls involved. This
+ -- ensures the proper pairing of the main warning and the
+ -- clarification messages generated by Output_Calls.
+
+ Output_Calls (N, Check_Elab_Flag => True);
+
+ -- Set flag to prevent further warnings for same unit unless in
+ -- All_Errors_Mode.
+
+ if not All_Errors_Mode and not Dynamic_Elaboration_Checks then
+ Set_Suppress_Elaboration_Warnings (W_Scope);
+ end if;
+ end if;
+
+ -- Check for runtime elaboration check required
+
+ if Dynamic_Elaboration_Checks then
+ if not Elaboration_Checks_Suppressed (Ent)
+ and then not Elaboration_Checks_Suppressed (W_Scope)
+ and then not Elaboration_Checks_Suppressed (E_Scope)
+ and then not Cunit_SC
+ then
+ -- Runtime elaboration check required. Generate check of the
+ -- elaboration Boolean for the unit containing the entity.
+
+ -- Note that for this case, we do check the real unit (the one
+ -- from following renamings, since that is the issue).
+
+ -- Could this possibly miss a useless but required PE???
+
+ Insert_Elab_Check (N,
+ Make_Attribute_Reference (Loc,
+ Attribute_Name => Name_Elaborated,
+ Prefix =>
+ New_Occurrence_Of (Spec_Entity (E_Scope), Loc)));
+
+ -- Prevent duplicate elaboration checks on the same call, which
+ -- can happen if the body enclosing the call appears itself in a
+ -- call whose elaboration check is delayed.
+
+ if Nkind (N) in N_Subprogram_Call then
+ Set_No_Elaboration_Check (N);
+ end if;
+ end if;
+
+ -- Case of static elaboration model
+
+ else
+ -- Do not do anything if elaboration checks suppressed. Note that
+ -- we check Ent here, not E, since we want the real entity for the
+ -- body to see if checks are suppressed for it, not the dummy
+ -- entry for renamings or derivations.
+
+ if Elaboration_Checks_Suppressed (Ent)
+ or else Elaboration_Checks_Suppressed (E_Scope)
+ or else Elaboration_Checks_Suppressed (W_Scope)
+ then
+ null;
+
+ -- Do not generate an Elaborate_All for finalization routines
+ -- that perform partial clean up as part of initialization.
+
+ elsif In_Init_Proc and then Is_Finalization_Procedure (Ent) then
+ null;
+
+ -- Here we need to generate an implicit elaborate all
+
+ else
+ -- Generate Elaborate_All warning unless suppressed
+
+ if (Elab_Info_Messages and Generate_Warnings and not Inst_Case)
+ and then not Suppress_Elaboration_Warnings (Ent)
+ and then not Suppress_Elaboration_Warnings (E_Scope)
+ and then not Suppress_Elaboration_Warnings (W_Scope)
+ then
+ Error_Msg_Node_2 := W_Scope;
+ Error_Msg_NE
+ ("info: call to& in elaboration code requires pragma "
+ & "Elaborate_All on&?$?", N, E);
+ end if;
+
+ -- Set indication for binder to generate Elaborate_All
+
+ Set_Elaboration_Constraint (N, E, W_Scope);
+ end if;
+ end if;
+ end Check_A_Call;
+
+ -----------------------------
+ -- Check_Bad_Instantiation --
+ -----------------------------
+
+ procedure Check_Bad_Instantiation (N : Node_Id) is
+ Ent : Entity_Id;
+
+ begin
+ -- Nothing to do if we do not have an instantiation (happens in some
+ -- error cases, and also in the formal package declaration case)
+
+ if Nkind (N) not in N_Generic_Instantiation then
+ return;
+
+ -- Nothing to do if serious errors detected (avoid cascaded errors)
+
+ elsif Serious_Errors_Detected /= 0 then
+ return;
+
+ -- Nothing to do if not in full analysis mode
+
+ elsif not Full_Analysis then
+ return;
+
+ -- Nothing to do if inside a generic template
+
+ elsif Inside_A_Generic then
+ return;
+
+ -- Nothing to do if a library level instantiation
+
+ elsif Nkind (Parent (N)) = N_Compilation_Unit then
+ return;
+
+ -- Nothing to do if we are compiling a proper body for semantic
+ -- purposes only. The generic body may be in another proper body.
+
+ elsif
+ Nkind (Parent (Unit_Declaration_Node (Main_Unit_Entity))) = N_Subunit
+ then
+ return;
+ end if;
+
+ Ent := Get_Generic_Entity (N);
+
+ -- The case we are interested in is when the generic spec is in the
+ -- current declarative part
+
+ if not Same_Elaboration_Scope (Current_Scope, Scope (Ent))
+ or else not In_Same_Extended_Unit (N, Ent)
+ then
+ return;
+ end if;
+
+ -- If the generic entity is within a deeper instance than we are, then
+ -- either the instantiation to which we refer itself caused an ABE, in
+ -- which case that will be handled separately. Otherwise, we know that
+ -- the body we need appears as needed at the point of the instantiation.
+ -- If they are both at the same level but not within the same instance
+ -- then the body of the generic will be in the earlier instance.
+
+ declare
+ D1 : constant Nat := Instantiation_Depth (Sloc (Ent));
+ D2 : constant Nat := Instantiation_Depth (Sloc (N));
+
+ begin
+ if D1 > D2 then
+ return;
+
+ elsif D1 = D2
+ and then Is_Generic_Instance (Scope (Ent))
+ and then not In_Open_Scopes (Scope (Ent))
+ then
+ return;
+ end if;
+ end;
+
+ -- Now we can proceed, if the entity being called has a completion,
+ -- then we are definitely OK, since we have already seen the body.
+
+ if Has_Completion (Ent) then
+ return;
+ end if;
+
+ -- If there is no body, then nothing to do
+
+ if not Has_Generic_Body (N) then
+ return;
+ end if;
+
+ -- Here we definitely have a bad instantiation
+
+ Error_Msg_Warn := SPARK_Mode /= On;
+ Error_Msg_NE ("cannot instantiate& before body seen<<", N, Ent);
+ Error_Msg_N ("\Program_Error [<<", N);
+
+ Insert_Elab_Check (N);
+ Set_Is_Known_Guaranteed_ABE (N);
+ end Check_Bad_Instantiation;
+
+ ---------------------
+ -- Check_Elab_Call --
+ ---------------------
+
+ procedure Check_Elab_Call
+ (N : Node_Id;
+ Outer_Scope : Entity_Id := Empty;
+ In_Init_Proc : Boolean := False)
+ is
+ Ent : Entity_Id;
+ P : Node_Id;
+
+ begin
+ pragma Assert (Legacy_Elaboration_Checks);
+
+ -- If the reference is not in the main unit, there is nothing to check.
+ -- Elaboration call from units in the context of the main unit will lead
+ -- to semantic dependencies when those units are compiled.
+
+ if not In_Extended_Main_Code_Unit (N) then
+ return;
+ end if;
+
+ -- For an entry call, check relevant restriction
+
+ if Nkind (N) = N_Entry_Call_Statement
+ and then not In_Subprogram_Or_Concurrent_Unit
+ then
+ Check_Restriction (No_Entry_Calls_In_Elaboration_Code, N);
+
+ -- Nothing to do if this is not an expected type of reference (happens
+ -- in some error conditions, and in some cases where rewriting occurs).
+
+ elsif Nkind (N) not in N_Subprogram_Call
+ and then Nkind (N) /= N_Attribute_Reference
+ and then (SPARK_Mode /= On
+ or else Nkind (N) not in N_Has_Entity
+ or else No (Entity (N))
+ or else Ekind (Entity (N)) /= E_Variable)
+ then
+ return;
+
+ -- Nothing to do if this is a call already rewritten for elab checking.
+ -- Such calls appear as the targets of If_Expressions.
+
+ -- This check MUST be wrong, it catches far too much
+
+ elsif Nkind (Parent (N)) = N_If_Expression then
+ return;
+
+ -- Nothing to do if inside a generic template
+
+ elsif Inside_A_Generic
+ and then No (Enclosing_Generic_Body (N))
+ then
+ return;
+
+ -- Nothing to do if call is being pre-analyzed, as when within a
+ -- pre/postcondition, a predicate, or an invariant.
+
+ elsif In_Spec_Expression then
+ return;
+ end if;
+
+ -- Nothing to do if this is a call to a postcondition, which is always
+ -- within a subprogram body, even though the current scope may be the
+ -- enclosing scope of the subprogram.
+
+ if Nkind (N) = N_Procedure_Call_Statement
+ and then Is_Entity_Name (Name (N))
+ and then Chars (Entity (Name (N))) = Name_uPostconditions
+ then
+ return;
+ end if;
+
+ -- Here we have a reference at elaboration time that must be checked
+
+ if Debug_Flag_Underscore_LL then
+ Write_Str (" Check_Elab_Ref: ");
+
+ if Nkind (N) = N_Attribute_Reference then
+ if not Is_Entity_Name (Prefix (N)) then
+ Write_Str ("<<not entity name>>");
+ else
+ Write_Name (Chars (Entity (Prefix (N))));
+ end if;
+
+ Write_Str ("'Access");
+
+ elsif No (Name (N)) or else not Is_Entity_Name (Name (N)) then
+ Write_Str ("<<not entity name>> ");
+
+ else
+ Write_Name (Chars (Entity (Name (N))));
+ end if;
+
+ Write_Str (" reference at ");
+ Write_Location (Sloc (N));
+ Write_Eol;
+ end if;
+
+ -- Climb up the tree to make sure we are not inside default expression
+ -- of a parameter specification or a record component, since in both
+ -- these cases, we will be doing the actual reference later, not now,
+ -- and it is at the time of the actual reference (statically speaking)
+ -- that we must do our static check, not at the time of its initial
+ -- analysis).
+
+ -- However, we have to check references within component definitions
+ -- (e.g. a function call that determines an array component bound),
+ -- so we terminate the loop in that case.
+
+ P := Parent (N);
+ while Present (P) loop
+ if Nkind_In (P, N_Parameter_Specification,
+ N_Component_Declaration)
+ then
+ return;
+
+ -- The reference occurs within the constraint of a component,
+ -- so it must be checked.
+
+ elsif Nkind (P) = N_Component_Definition then
+ exit;
+
+ else
+ P := Parent (P);
+ end if;
+ end loop;
+
+ -- Stuff that happens only at the outer level
+
+ if No (Outer_Scope) then
+ Elab_Visited.Set_Last (0);
+
+ -- Nothing to do if current scope is Standard (this is a bit odd, but
+ -- it happens in the case of generic instantiations).
+
+ C_Scope := Current_Scope;
+
+ if C_Scope = Standard_Standard then
+ return;
+ end if;
+
+ -- First case, we are in elaboration code
+
+ From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit;
+
+ if From_Elab_Code then
+
+ -- Complain if ref that comes from source in preelaborated unit
+ -- and we are not inside a subprogram (i.e. we are in elab code).
+
+ if Comes_From_Source (N)
+ and then In_Preelaborated_Unit
+ and then not In_Inlined_Body
+ and then Nkind (N) /= N_Attribute_Reference
+ then
+ -- This is a warning in GNAT mode allowing such calls to be
+ -- used in the predefined library with appropriate care.
+
+ Error_Msg_Warn := GNAT_Mode;
+ Error_Msg_N
+ ("<<non-static call not allowed in preelaborated unit", N);
+ return;
+ end if;
+
+ -- Second case, we are inside a subprogram or concurrent unit, which
+ -- means we are not in elaboration code.
+
+ else
+ -- In this case, the issue is whether we are inside the
+ -- declarative part of the unit in which we live, or inside its
+ -- statements. In the latter case, there is no issue of ABE calls
+ -- at this level (a call from outside to the unit in which we live
+ -- might cause an ABE, but that will be detected when we analyze
+ -- that outer level call, as it recurses into the called unit).
+
+ -- Climb up the tree, doing this test, and also testing for being
+ -- inside a default expression, which, as discussed above, is not
+ -- checked at this stage.
+
+ declare
+ P : Node_Id;
+ L : List_Id;
+
+ begin
+ P := N;
+ loop
+ -- If we find a parentless subtree, it seems safe to assume
+ -- that we are not in a declarative part and that no
+ -- checking is required.
+
+ if No (P) then
+ return;
+ end if;
+
+ if Is_List_Member (P) then
+ L := List_Containing (P);
+ P := Parent (L);
+ else
+ L := No_List;
+ P := Parent (P);
+ end if;
+
+ exit when Nkind (P) = N_Subunit;
+
+ -- Filter out case of default expressions, where we do not
+ -- do the check at this stage.
+
+ if Nkind_In (P, N_Parameter_Specification,
+ N_Component_Declaration)
+ then
+ return;
+ end if;
+
+ -- A protected body has no elaboration code and contains
+ -- only other bodies.
+
+ if Nkind (P) = N_Protected_Body then
+ return;
+
+ elsif Nkind_In (P, N_Subprogram_Body,
+ N_Task_Body,
+ N_Block_Statement,
+ N_Entry_Body)
+ then
+ if L = Declarations (P) then
+ exit;
+
+ -- We are not in elaboration code, but we are doing
+ -- dynamic elaboration checks, in this case, we still
+ -- need to do the reference, since the subprogram we are
+ -- in could be called from another unit, also in dynamic
+ -- elaboration check mode, at elaboration time.
+
+ elsif Dynamic_Elaboration_Checks then
+
+ -- We provide a debug flag to disable this check. That
+ -- way we have an easy work around for regressions
+ -- that are caused by this new check. This debug flag
+ -- can be removed later.
+
+ if Debug_Flag_DD then
+ return;
+ end if;
+
+ -- Do the check in this case
+
+ exit;
+
+ elsif Nkind (P) = N_Task_Body then
+
+ -- The check is deferred until Check_Task_Activation
+ -- but we need to capture local suppress pragmas
+ -- that may inhibit checks on this call.
+
+ Ent := Get_Referenced_Ent (N);
+
+ if No (Ent) then
+ return;
+
+ elsif Elaboration_Checks_Suppressed (Current_Scope)
+ or else Elaboration_Checks_Suppressed (Ent)
+ or else Elaboration_Checks_Suppressed (Scope (Ent))
+ then
+ if Nkind (N) in N_Subprogram_Call then
+ Set_No_Elaboration_Check (N);
+ end if;
+ end if;
+
+ return;
+
+ -- Static model, call is not in elaboration code, we
+ -- never need to worry, because in the static model the
+ -- top-level caller always takes care of things.
+
+ else
+ return;
+ end if;
+ end if;
+ end loop;
+ end;
+ end if;
+ end if;
+
+ Ent := Get_Referenced_Ent (N);
+
+ if No (Ent) then
+ return;
+ end if;
+
+ -- Determine whether a prior call to the same subprogram was already
+ -- examined within the same context. If this is the case, then there is
+ -- no need to proceed with the various warnings and checks because the
+ -- work was already done for the previous call.
+
+ declare
+ Self : constant Visited_Element :=
+ (Subp_Id => Ent, Context => Parent (N));
+
+ begin
+ for Index in 1 .. Elab_Visited.Last loop
+ if Self = Elab_Visited.Table (Index) then
+ return;
+ end if;
+ end loop;
+ end;
+
+ -- See if we need to analyze this reference. We analyze it if either of
+ -- the following conditions is met:
+
+ -- It is an inner level call (since in this case it was triggered
+ -- by an outer level call from elaboration code), but only if the
+ -- call is within the scope of the original outer level call.
+
+ -- It is an outer level reference from elaboration code, or a call to
+ -- an entity is in the same elaboration scope.
+
+ -- And in these cases, we will check both inter-unit calls and
+ -- intra-unit (within a single unit) calls.
+
+ C_Scope := Current_Scope;
+
+ -- If not outer level reference, then we follow it if it is within the
+ -- original scope of the outer reference.
+
+ if Present (Outer_Scope)
+ and then Within (Scope (Ent), Outer_Scope)
+ then
+ Set_C_Scope;
+ Check_A_Call
+ (N => N,
+ E => Ent,
+ Outer_Scope => Outer_Scope,
+ Inter_Unit_Only => False,
+ In_Init_Proc => In_Init_Proc);
+
+ -- Nothing to do if elaboration checks suppressed for this scope.
+ -- However, an interesting exception, the fact that elaboration checks
+ -- are suppressed within an instance (because we can trace the body when
+ -- we process the template) does not extend to calls to generic formal
+ -- subprograms.
+
+ elsif Elaboration_Checks_Suppressed (Current_Scope)
+ and then not Is_Call_Of_Generic_Formal (N)
+ then
+ null;
+
+ elsif From_Elab_Code then
+ Set_C_Scope;
+ Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False);
+
+ elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then
+ Set_C_Scope;
+ Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False);
+
+ -- If none of those cases holds, but Dynamic_Elaboration_Checks mode
+ -- is set, then we will do the check, but only in the inter-unit case
+ -- (this is to accommodate unguarded elaboration calls from other units
+ -- in which this same mode is set). We don't want warnings in this case,
+ -- it would generate warnings having nothing to do with elaboration.
+
+ elsif Dynamic_Elaboration_Checks then
+ Set_C_Scope;
+ Check_A_Call
+ (N,
+ Ent,
+ Standard_Standard,
+ Inter_Unit_Only => True,
+ Generate_Warnings => False);
+
+ -- Otherwise nothing to do
+
+ else
+ return;
+ end if;
+
+ -- A call to an Init_Proc in elaboration code may bring additional
+ -- dependencies, if some of the record components thereof have
+ -- initializations that are function calls that come from source. We
+ -- treat the current node as a call to each of these functions, to check
+ -- their elaboration impact.
+
+ if Is_Init_Proc (Ent) and then From_Elab_Code then
+ Process_Init_Proc : declare
+ Unit_Decl : constant Node_Id := Unit_Declaration_Node (Ent);
+
+ function Check_Init_Call (Nod : Node_Id) return Traverse_Result;
+ -- Find subprogram calls within body of Init_Proc for Traverse
+ -- instantiation below.
+
+ procedure Traverse_Body is new Traverse_Proc (Check_Init_Call);
+ -- Traversal procedure to find all calls with body of Init_Proc
+
+ ---------------------
+ -- Check_Init_Call --
+ ---------------------
+
+ function Check_Init_Call (Nod : Node_Id) return Traverse_Result is
+ Func : Entity_Id;
+
+ begin
+ if Nkind (Nod) in N_Subprogram_Call
+ and then Is_Entity_Name (Name (Nod))
+ then
+ Func := Entity (Name (Nod));
+
+ if Comes_From_Source (Func) then
+ Check_A_Call
+ (N, Func, Standard_Standard, Inter_Unit_Only => True);
+ end if;
+
+ return OK;
+
+ else
+ return OK;
+ end if;
+ end Check_Init_Call;
+
+ -- Start of processing for Process_Init_Proc
+
+ begin
+ if Nkind (Unit_Decl) = N_Subprogram_Body then
+ Traverse_Body (Handled_Statement_Sequence (Unit_Decl));
+ end if;
+ end Process_Init_Proc;
+ end if;
+ end Check_Elab_Call;
+
+ -----------------------
+ -- Check_Elab_Assign --
+ -----------------------
+
+ procedure Check_Elab_Assign (N : Node_Id) is
+ Ent : Entity_Id;
+ Scop : Entity_Id;
+
+ Pkg_Spec : Entity_Id;
+ Pkg_Body : Entity_Id;
+
+ begin
+ pragma Assert (Legacy_Elaboration_Checks);
+
+ -- For record or array component, check prefix. If it is an access type,
+ -- then there is nothing to do (we do not know what is being assigned),
+ -- but otherwise this is an assignment to the prefix.
+
+ if Nkind_In (N, N_Indexed_Component,
+ N_Selected_Component,
+ N_Slice)
+ then
+ if not Is_Access_Type (Etype (Prefix (N))) then
+ Check_Elab_Assign (Prefix (N));
+ end if;
+
+ return;
+ end if;
+
+ -- For type conversion, check expression
+
+ if Nkind (N) = N_Type_Conversion then
+ Check_Elab_Assign (Expression (N));
+ return;
+ end if;
+
+ -- Nothing to do if this is not an entity reference otherwise get entity
+
+ if Is_Entity_Name (N) then
+ Ent := Entity (N);
+ else
+ return;
+ end if;
+
+ -- What we are looking for is a reference in the body of a package that
+ -- modifies a variable declared in the visible part of the package spec.
+
+ if Present (Ent)
+ and then Comes_From_Source (N)
+ and then not Suppress_Elaboration_Warnings (Ent)
+ and then Ekind (Ent) = E_Variable
+ and then not In_Private_Part (Ent)
+ and then Is_Library_Level_Entity (Ent)
+ then
+ Scop := Current_Scope;
+ loop
+ if No (Scop) or else Scop = Standard_Standard then
+ return;
+ elsif Ekind (Scop) = E_Package
+ and then Is_Compilation_Unit (Scop)
+ then
+ exit;
+ else
+ Scop := Scope (Scop);
+ end if;
+ end loop;
+
+ -- Here Scop points to the containing library package
+
+ Pkg_Spec := Scop;
+ Pkg_Body := Body_Entity (Pkg_Spec);
+
+ -- All OK if the package has an Elaborate_Body pragma
+
+ if Has_Pragma_Elaborate_Body (Scop) then
+ return;
+ end if;
+
+ -- OK if entity being modified is not in containing package spec
+
+ if not In_Same_Source_Unit (Scop, Ent) then
+ return;
+ end if;
+
+ -- All OK if entity appears in generic package or generic instance.
+ -- We just get too messed up trying to give proper warnings in the
+ -- presence of generics. Better no message than a junk one.
+
+ Scop := Scope (Ent);
+ while Present (Scop) and then Scop /= Pkg_Spec loop
+ if Ekind (Scop) = E_Generic_Package then
+ return;
+ elsif Ekind (Scop) = E_Package
+ and then Is_Generic_Instance (Scop)
+ then
+ return;
+ end if;
+
+ Scop := Scope (Scop);
+ end loop;
+
+ -- All OK if in task, don't issue warnings there
+
+ if In_Task_Activation then
+ return;
+ end if;
+
+ -- OK if no package body
+
+ if No (Pkg_Body) then
+ return;
+ end if;
+
+ -- OK if reference is not in package body
+
+ if not In_Same_Source_Unit (Pkg_Body, N) then
+ return;
+ end if;
+
+ -- OK if package body has no handled statement sequence
+
+ declare
+ HSS : constant Node_Id :=
+ Handled_Statement_Sequence (Declaration_Node (Pkg_Body));
+ begin
+ if No (HSS) or else not Comes_From_Source (HSS) then
+ return;
+ end if;
+ end;
+
+ -- We definitely have a case of a modification of an entity in
+ -- the package spec from the elaboration code of the package body.
+ -- We may not give the warning (because there are some additional
+ -- checks to avoid too many false positives), but it would be a good
+ -- idea for the binder to try to keep the body elaboration close to
+ -- the spec elaboration.
+
+ Set_Elaborate_Body_Desirable (Pkg_Spec);
+
+ -- All OK in gnat mode (we know what we are doing)
+
+ if GNAT_Mode then
+ return;
+ end if;
+
+ -- All OK if all warnings suppressed
+
+ if Warning_Mode = Suppress then
+ return;
+ end if;
+
+ -- All OK if elaboration checks suppressed for entity
+
+ if Checks_May_Be_Suppressed (Ent)
+ and then Is_Check_Suppressed (Ent, Elaboration_Check)
+ then
+ return;
+ end if;
+
+ -- OK if the entity is initialized. Note that the No_Initialization
+ -- flag usually means that the initialization has been rewritten into
+ -- assignments, but that still counts for us.
+
+ declare
+ Decl : constant Node_Id := Declaration_Node (Ent);
+ begin
+ if Nkind (Decl) = N_Object_Declaration
+ and then (Present (Expression (Decl))
+ or else No_Initialization (Decl))
+ then
+ return;
+ end if;
+ end;
+
+ -- Here is where we give the warning
+
+ -- All OK if warnings suppressed on the entity
+
+ if not Has_Warnings_Off (Ent) then
+ Error_Msg_Sloc := Sloc (Ent);
+
+ Error_Msg_NE
+ ("??& can be accessed by clients before this initialization",
+ N, Ent);
+ Error_Msg_NE
+ ("\??add Elaborate_Body to spec to ensure & is initialized",
+ N, Ent);
+ end if;
+
+ if not All_Errors_Mode then
+ Set_Suppress_Elaboration_Warnings (Ent);
+ end if;
+ end if;
+ end Check_Elab_Assign;
+
+ ----------------------
+ -- Check_Elab_Calls --
+ ----------------------
+
+ -- WARNING: This routine manages SPARK regions
+
+ procedure Check_Elab_Calls is
+ Saved_SM : SPARK_Mode_Type;
+ Saved_SMP : Node_Id;
+
+ begin
+ pragma Assert (Legacy_Elaboration_Checks);
+
+ -- If expansion is disabled, do not generate any checks, unless we
+ -- are in GNATprove mode, so that errors are issued in GNATprove for
+ -- violations of static elaboration rules in SPARK code. Also skip
+ -- checks if any subunits are missing because in either case we lack the
+ -- full information that we need, and no object file will be created in
+ -- any case.
+
+ if (not Expander_Active and not GNATprove_Mode)
+ or else Is_Generic_Unit (Cunit_Entity (Main_Unit))
+ or else Subunits_Missing
+ then
+ return;
+ end if;
+
+ -- Skip delayed calls if we had any errors
+
+ if Serious_Errors_Detected = 0 then
+ Delaying_Elab_Checks := False;
+ Expander_Mode_Save_And_Set (True);
+
+ for J in Delay_Check.First .. Delay_Check.Last loop
+ Push_Scope (Delay_Check.Table (J).Curscop);
+ From_Elab_Code := Delay_Check.Table (J).From_Elab_Code;
+ In_Task_Activation := Delay_Check.Table (J).In_Task_Activation;
+
+ Saved_SM := SPARK_Mode;
+ Saved_SMP := SPARK_Mode_Pragma;
+
+ -- Set appropriate value of SPARK_Mode
+
+ if Delay_Check.Table (J).From_SPARK_Code then
+ SPARK_Mode := On;
+ end if;
+
+ Check_Internal_Call_Continue
+ (N => Delay_Check.Table (J).N,
+ E => Delay_Check.Table (J).E,
+ Outer_Scope => Delay_Check.Table (J).Outer_Scope,
+ Orig_Ent => Delay_Check.Table (J).Orig_Ent);
+
+ Restore_SPARK_Mode (Saved_SM, Saved_SMP);
+ Pop_Scope;
+ end loop;
+
+ -- Set Delaying_Elab_Checks back on for next main compilation
+
+ Expander_Mode_Restore;
+ Delaying_Elab_Checks := True;
+ end if;
+ end Check_Elab_Calls;
+
+ ------------------------------
+ -- Check_Elab_Instantiation --
+ ------------------------------
+
+ procedure Check_Elab_Instantiation
+ (N : Node_Id;
+ Outer_Scope : Entity_Id := Empty)
+ is
+ Ent : Entity_Id;
+
+ begin
+ pragma Assert (Legacy_Elaboration_Checks);
+
+ -- Check for and deal with bad instantiation case. There is some
+ -- duplicated code here, but we will worry about this later ???
+
+ Check_Bad_Instantiation (N);
+
+ if Is_Known_Guaranteed_ABE (N) then
+ return;
+ end if;
+
+ -- Nothing to do if we do not have an instantiation (happens in some
+ -- error cases, and also in the formal package declaration case)
+
+ if Nkind (N) not in N_Generic_Instantiation then
+ return;
+ end if;
+
+ -- Nothing to do if inside a generic template
+
+ if Inside_A_Generic then
+ return;
+ end if;
+
+ -- Nothing to do if the instantiation is not in the main unit
+
+ if not In_Extended_Main_Code_Unit (N) then
+ return;
+ end if;
+
+ Ent := Get_Generic_Entity (N);
+ From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit;
+
+ -- See if we need to analyze this instantiation. We analyze it if
+ -- either of the following conditions is met:
+
+ -- It is an inner level instantiation (since in this case it was
+ -- triggered by an outer level call from elaboration code), but
+ -- only if the instantiation is within the scope of the original
+ -- outer level call.
+
+ -- It is an outer level instantiation from elaboration code, or the
+ -- instantiated entity is in the same elaboration scope.
+
+ -- And in these cases, we will check both the inter-unit case and
+ -- the intra-unit (within a single unit) case.
+
+ C_Scope := Current_Scope;
+
+ if Present (Outer_Scope) and then Within (Scope (Ent), Outer_Scope) then
+ Set_C_Scope;
+ Check_A_Call (N, Ent, Outer_Scope, Inter_Unit_Only => False);
+
+ elsif From_Elab_Code then
+ Set_C_Scope;
+ Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False);
+
+ elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then
+ Set_C_Scope;
+ Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False);
+
+ -- If none of those cases holds, but Dynamic_Elaboration_Checks mode is
+ -- set, then we will do the check, but only in the inter-unit case (this
+ -- is to accommodate unguarded elaboration calls from other units in
+ -- which this same mode is set). We inhibit warnings in this case, since
+ -- this instantiation is not occurring in elaboration code.
+
+ elsif Dynamic_Elaboration_Checks then
+ Set_C_Scope;
+ Check_A_Call
+ (N,
+ Ent,
+ Standard_Standard,
+ Inter_Unit_Only => True,
+ Generate_Warnings => False);
+
+ else
+ return;
+ end if;
+ end Check_Elab_Instantiation;
+
+ -------------------------
+ -- Check_Internal_Call --
+ -------------------------
+
+ procedure Check_Internal_Call
+ (N : Node_Id;
+ E : Entity_Id;
+ Outer_Scope : Entity_Id;
+ Orig_Ent : Entity_Id)
+ is
+ function Within_Initial_Condition (Call : Node_Id) return Boolean;
+ -- Determine whether call Call occurs within pragma Initial_Condition or
+ -- pragma Check with check_kind set to Initial_Condition.
+
+ ------------------------------
+ -- Within_Initial_Condition --
+ ------------------------------
+
+ function Within_Initial_Condition (Call : Node_Id) return Boolean is
+ Args : List_Id;
+ Nam : Name_Id;
+ Par : Node_Id;
+
+ begin
+ -- Traverse the parent chain looking for an enclosing pragma
+
+ Par := Call;
+ while Present (Par) loop
+ if Nkind (Par) = N_Pragma then
+ Nam := Pragma_Name (Par);
+
+ -- Pragma Initial_Condition appears in its alternative from as
+ -- Check (Initial_Condition, ...).
+
+ if Nam = Name_Check then
+ Args := Pragma_Argument_Associations (Par);
+
+ -- Pragma Check should have at least two arguments
+
+ pragma Assert (Present (Args));
+
+ return
+ Chars (Expression (First (Args))) = Name_Initial_Condition;
+
+ -- Direct match
+
+ elsif Nam = Name_Initial_Condition then
+ return True;
+
+ -- Since pragmas are never nested within other pragmas, stop
+ -- the traversal.
+
+ else
+ return False;
+ end if;
+
+ -- Prevent the search from going too far
+
+ elsif Is_Body_Or_Package_Declaration (Par) then
+ exit;
+ end if;
+
+ Par := Parent (Par);
+
+ -- If assertions are not enabled, the check pragma is rewritten
+ -- as an if_statement in sem_prag, to generate various warnings
+ -- on boolean expressions. Retrieve the original pragma.
+
+ if Nkind (Original_Node (Par)) = N_Pragma then
+ Par := Original_Node (Par);
+ end if;
+ end loop;
+
+ return False;
+ end Within_Initial_Condition;
+
+ -- Local variables
+
+ Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation;
+
+ -- Start of processing for Check_Internal_Call
+
+ begin
+ -- For P'Access, we want to warn if the -gnatw.f switch is set, and the
+ -- node comes from source.
+
+ if Nkind (N) = N_Attribute_Reference
+ and then ((not Warn_On_Elab_Access and then not Debug_Flag_Dot_O)
+ or else not Comes_From_Source (N))
+ then
+ return;
+
+ -- If not function or procedure call, instantiation, or 'Access, then
+ -- ignore call (this happens in some error cases and rewriting cases).
+
+ elsif not Nkind_In (N, N_Attribute_Reference,
+ N_Function_Call,
+ N_Procedure_Call_Statement)
+ and then not Inst_Case
+ then
+ return;
+
+ -- Nothing to do if this is a call or instantiation that has already
+ -- been found to be a sure ABE.
+
+ elsif Nkind (N) /= N_Attribute_Reference
+ and then Is_Known_Guaranteed_ABE (N)
+ then
+ return;
+
+ -- Nothing to do if errors already detected (avoid cascaded errors)
+
+ elsif Serious_Errors_Detected /= 0 then
+ return;
+
+ -- Nothing to do if not in full analysis mode
+
+ elsif not Full_Analysis then
+ return;
+
+ -- Nothing to do if analyzing in special spec-expression mode, since the
+ -- call is not actually being made at this time.
+
+ elsif In_Spec_Expression then
+ return;
+
+ -- Nothing to do for call to intrinsic subprogram
+
+ elsif Is_Intrinsic_Subprogram (E) then
+ return;
+
+ -- Nothing to do if call is within a generic unit
+
+ elsif Inside_A_Generic then
+ return;
+
+ -- Nothing to do when the call appears within pragma Initial_Condition.
+ -- The pragma is part of the elaboration statements of a package body
+ -- and may only call external subprograms or subprograms whose body is
+ -- already available.
+
+ elsif Within_Initial_Condition (N) then
+ return;
+ end if;
+
+ -- Delay this call if we are still delaying calls
+
+ if Delaying_Elab_Checks then
+ Delay_Check.Append
+ ((N => N,
+ E => E,
+ Orig_Ent => Orig_Ent,
+ Curscop => Current_Scope,
+ Outer_Scope => Outer_Scope,
+ From_Elab_Code => From_Elab_Code,
+ In_Task_Activation => In_Task_Activation,
+ From_SPARK_Code => SPARK_Mode = On));
+ return;
+
+ -- Otherwise, call phase 2 continuation right now
+
+ else
+ Check_Internal_Call_Continue (N, E, Outer_Scope, Orig_Ent);
+ end if;
+ end Check_Internal_Call;
+
+ ----------------------------------
+ -- Check_Internal_Call_Continue --
+ ----------------------------------
+
+ procedure Check_Internal_Call_Continue
+ (N : Node_Id;
+ E : Entity_Id;
+ Outer_Scope : Entity_Id;
+ Orig_Ent : Entity_Id)
+ is
+ function Find_Elab_Reference (N : Node_Id) return Traverse_Result;
+ -- Function applied to each node as we traverse the body. Checks for
+ -- call or entity reference that needs checking, and if so checks it.
+ -- Always returns OK, so entire tree is traversed, except that as
+ -- described below subprogram bodies are skipped for now.
+
+ procedure Traverse is new Atree.Traverse_Proc (Find_Elab_Reference);
+ -- Traverse procedure using above Find_Elab_Reference function
+
+ -------------------------
+ -- Find_Elab_Reference --
+ -------------------------
+
+ function Find_Elab_Reference (N : Node_Id) return Traverse_Result is
+ Actual : Node_Id;
+
+ begin
+ -- If user has specified that there are no entry calls in elaboration
+ -- code, do not trace past an accept statement, because the rendez-
+ -- vous will happen after elaboration.
+
+ if Nkind_In (Original_Node (N), N_Accept_Statement,
+ N_Selective_Accept)
+ and then Restriction_Active (No_Entry_Calls_In_Elaboration_Code)
+ then
+ return Abandon;
+
+ -- If we have a function call, check it
+
+ elsif Nkind (N) = N_Function_Call then
+ Check_Elab_Call (N, Outer_Scope);
+ return OK;
+
+ -- If we have a procedure call, check the call, and also check
+ -- arguments that are assignments (OUT or IN OUT mode formals).
+
+ elsif Nkind (N) = N_Procedure_Call_Statement then
+ Check_Elab_Call (N, Outer_Scope, In_Init_Proc => Is_Init_Proc (E));
+
+ Actual := First_Actual (N);
+ while Present (Actual) loop
+ if Known_To_Be_Assigned (Actual) then
+ Check_Elab_Assign (Actual);
+ end if;
+
+ Next_Actual (Actual);
+ end loop;
+
+ return OK;
+
+ -- If we have an access attribute for a subprogram, check it.
+ -- Suppress this behavior under debug flag.
+
+ elsif not Debug_Flag_Dot_UU
+ and then Nkind (N) = N_Attribute_Reference
+ and then Nam_In (Attribute_Name (N), Name_Access,
+ Name_Unrestricted_Access)
+ and then Is_Entity_Name (Prefix (N))
+ and then Is_Subprogram (Entity (Prefix (N)))
+ then
+ Check_Elab_Call (N, Outer_Scope);
+ return OK;
+
+ -- In SPARK mode, if we have an entity reference to a variable, then
+ -- check it. For now we consider any reference.
+
+ elsif SPARK_Mode = On
+ and then Nkind (N) in N_Has_Entity
+ and then Present (Entity (N))
+ and then Ekind (Entity (N)) = E_Variable
+ then
+ Check_Elab_Call (N, Outer_Scope);
+ return OK;
+
+ -- If we have a generic instantiation, check it
+
+ elsif Nkind (N) in N_Generic_Instantiation then
+ Check_Elab_Instantiation (N, Outer_Scope);
+ return OK;
+
+ -- Skip subprogram bodies that come from source (wait for call to
+ -- analyze these). The reason for the come from source test is to
+ -- avoid catching task bodies.
+
+ -- For task bodies, we should really avoid these too, waiting for the
+ -- task activation, but that's too much trouble to catch for now, so
+ -- we go in unconditionally. This is not so terrible, it means the
+ -- error backtrace is not quite complete, and we are too eager to
+ -- scan bodies of tasks that are unused, but this is hardly very
+ -- significant.
+
+ elsif Nkind (N) = N_Subprogram_Body
+ and then Comes_From_Source (N)
+ then
+ return Skip;
+
+ elsif Nkind (N) = N_Assignment_Statement
+ and then Comes_From_Source (N)
+ then
+ Check_Elab_Assign (Name (N));
+ return OK;
+
+ else
+ return OK;
+ end if;
+ end Find_Elab_Reference;
+
+ Inst_Case : constant Boolean := Is_Generic_Unit (E);
+ Loc : constant Source_Ptr := Sloc (N);
+
+ Ebody : Entity_Id;
+ Sbody : Node_Id;
+
+ -- Start of processing for Check_Internal_Call_Continue
+
+ begin
+ -- Save outer level call if at outer level
+
+ if Elab_Call.Last = 0 then
+ Outer_Level_Sloc := Loc;
+ end if;
+
+ -- If the call is to a function that renames a literal, no check needed
+
+ if Ekind (E) = E_Enumeration_Literal then
+ return;
+ end if;
+
+ -- Register the subprogram as examined within this particular context.
+ -- This ensures that calls to the same subprogram but in different
+ -- contexts receive warnings and checks of their own since the calls
+ -- may be reached through different flow paths.
+
+ Elab_Visited.Append ((Subp_Id => E, Context => Parent (N)));
+
+ Sbody := Unit_Declaration_Node (E);
+
+ if not Nkind_In (Sbody, N_Subprogram_Body, N_Package_Body) then
+ Ebody := Corresponding_Body (Sbody);
+
+ if No (Ebody) then
+ return;
+ else
+ Sbody := Unit_Declaration_Node (Ebody);
+ end if;
+ end if;
+
+ -- If the body appears after the outer level call or instantiation then
+ -- we have an error case handled below.
+
+ if Earlier_In_Extended_Unit (Outer_Level_Sloc, Sloc (Sbody))
+ and then not In_Task_Activation
+ then
+ null;
+
+ -- If we have the instantiation case we are done, since we now know that
+ -- the body of the generic appeared earlier.
+
+ elsif Inst_Case then
+ return;
+
+ -- Otherwise we have a call, so we trace through the called body to see
+ -- if it has any problems.
+
+ else
+ pragma Assert (Nkind (Sbody) = N_Subprogram_Body);
+
+ Elab_Call.Append ((Cloc => Loc, Ent => E));
+
+ if Debug_Flag_Underscore_LL then
+ Write_Str ("Elab_Call.Last = ");
+ Write_Int (Int (Elab_Call.Last));
+ Write_Str (" Ent = ");
+ Write_Name (Chars (E));
+ Write_Str (" at ");
+ Write_Location (Sloc (N));
+ Write_Eol;
+ end if;
+
+ -- Now traverse declarations and statements of subprogram body. Note
+ -- that we cannot simply Traverse (Sbody), since traverse does not
+ -- normally visit subprogram bodies.
+
+ declare
+ Decl : Node_Id;
+ begin
+ Decl := First (Declarations (Sbody));
+ while Present (Decl) loop
+ Traverse (Decl);
+ Next (Decl);
+ end loop;
+ end;
+
+ Traverse (Handled_Statement_Sequence (Sbody));
+
+ Elab_Call.Decrement_Last;
+ return;
+ end if;
+
+ -- Here is the case of calling a subprogram where the body has not yet
+ -- been encountered. A warning message is needed, except if this is the
+ -- case of appearing within an aspect specification that results in
+ -- a check call, we do not really have such a situation, so no warning
+ -- is needed (e.g. the case of a precondition, where the call appears
+ -- textually before the body, but in actual fact is moved to the
+ -- appropriate subprogram body and so does not need a check).
+
+ declare
+ P : Node_Id;
+ O : Node_Id;
+
+ begin
+ P := Parent (N);
+ loop
+ -- Keep looking at parents if we are still in the subexpression
+
+ if Nkind (P) in N_Subexpr then
+ P := Parent (P);
+
+ -- Here P is the parent of the expression, check for special case
+
+ else
+ O := Original_Node (P);
+
+ -- Definitely not the special case if orig node is not a pragma
+
+ exit when Nkind (O) /= N_Pragma;
+
+ -- Check we have an If statement or a null statement (happens
+ -- when the If has been expanded to be True).
+
+ exit when not Nkind_In (P, N_If_Statement, N_Null_Statement);
+
+ -- Our special case will be indicated either by the pragma
+ -- coming from an aspect ...
+
+ if Present (Corresponding_Aspect (O)) then
+ return;
+
+ -- Or, in the case of an initial condition, specifically by a
+ -- Check pragma specifying an Initial_Condition check.
+
+ elsif Pragma_Name (O) = Name_Check
+ and then
+ Chars
+ (Expression (First (Pragma_Argument_Associations (O)))) =
+ Name_Initial_Condition
+ then
+ return;
+
+ -- For anything else, we have an error
+
+ else
+ exit;
+ end if;
+ end if;
+ end loop;
+ end;
+
+ -- Not that special case, warning and dynamic check is required
+
+ -- If we have nothing in the call stack, then this is at the outer
+ -- level, and the ABE is bound to occur, unless it's a 'Access, or
+ -- it's a renaming.
+
+ if Elab_Call.Last = 0 then
+ Error_Msg_Warn := SPARK_Mode /= On;
+
+ declare
+ Insert_Check : Boolean := True;
+ -- This flag is set to True if an elaboration check should be
+ -- inserted.
+
+ begin
+ if In_Task_Activation then
+ Insert_Check := False;
+
+ elsif Inst_Case then
+ Error_Msg_NE
+ ("cannot instantiate& before body seen<<", N, Orig_Ent);
+
+ elsif Nkind (N) = N_Attribute_Reference then
+ Error_Msg_NE
+ ("Access attribute of & before body seen<<", N, Orig_Ent);
+ Error_Msg_N ("\possible Program_Error on later references<", N);
+ Insert_Check := False;
+
+ elsif Nkind (Unit_Declaration_Node (Orig_Ent)) /=
+ N_Subprogram_Renaming_Declaration
+ then
+ Error_Msg_NE
+ ("cannot call& before body seen<<", N, Orig_Ent);
+
+ elsif not Is_Generic_Actual_Subprogram (Orig_Ent) then
+ Insert_Check := False;
+ end if;
+
+ if Insert_Check then
+ Error_Msg_N ("\Program_Error [<<", N);
+ Insert_Elab_Check (N);
+ end if;
+ end;
+
+ -- Call is not at outer level
+
+ else
+ -- Do not generate elaboration checks in GNATprove mode because the
+ -- elaboration counter and the check are both forms of expansion.
+
+ if GNATprove_Mode then
+ null;
+
+ -- Generate an elaboration check
+
+ elsif not Elaboration_Checks_Suppressed (E) then
+ Set_Elaboration_Entity_Required (E);
+
+ -- Create a declaration of the elaboration entity, and insert it
+ -- prior to the subprogram or the generic unit, within the same
+ -- scope. Since the subprogram may be overloaded, create a unique
+ -- entity.
+
+ if No (Elaboration_Entity (E)) then
+ declare
+ Loce : constant Source_Ptr := Sloc (E);
+ Ent : constant Entity_Id :=
+ Make_Defining_Identifier (Loc,
+ New_External_Name (Chars (E), 'E', -1));
+
+ begin
+ Set_Elaboration_Entity (E, Ent);
+ Push_Scope (Scope (E));
+
+ Insert_Action (Declaration_Node (E),
+ Make_Object_Declaration (Loce,
+ Defining_Identifier => Ent,
+ Object_Definition =>
+ New_Occurrence_Of (Standard_Short_Integer, Loce),
+ Expression =>
+ Make_Integer_Literal (Loc, Uint_0)));
+
+ -- Set elaboration flag at the point of the body
+
+ Set_Elaboration_Flag (Sbody, E);
+
+ -- Kill current value indication. This is necessary because
+ -- the tests of this flag are inserted out of sequence and
+ -- must not pick up bogus indications of the wrong constant
+ -- value. Also, this is never a true constant, since one way
+ -- or another, it gets reset.
+
+ Set_Current_Value (Ent, Empty);
+ Set_Last_Assignment (Ent, Empty);
+ Set_Is_True_Constant (Ent, False);
+ Pop_Scope;
+ end;
+ end if;
+
+ -- Generate:
+ -- if Enn = 0 then
+ -- raise Program_Error with "access before elaboration";
+ -- end if;
+
+ Insert_Elab_Check (N,
+ Make_Attribute_Reference (Loc,
+ Attribute_Name => Name_Elaborated,
+ Prefix => New_Occurrence_Of (E, Loc)));
+ end if;
+
+ -- Generate the warning
+
+ if not Suppress_Elaboration_Warnings (E)
+ and then not Elaboration_Checks_Suppressed (E)
+
+ -- Suppress this warning if we have a function call that occurred
+ -- within an assertion expression, since we can get false warnings
+ -- in this case, due to the out of order handling in this case.
+
+ and then
+ (Nkind (Original_Node (N)) /= N_Function_Call
+ or else not In_Assertion_Expression_Pragma (Original_Node (N)))
+ then
+ Error_Msg_Warn := SPARK_Mode /= On;
+
+ if Inst_Case then
+ Error_Msg_NE
+ ("instantiation of& may occur before body is seen<l<",
+ N, Orig_Ent);
+ else
+ -- A rather specific check. For Finalize/Adjust/Initialize, if
+ -- the type has Warnings_Off set, suppress the warning.
+
+ if Nam_In (Chars (E), Name_Adjust,
+ Name_Finalize,
+ Name_Initialize)
+ and then Present (First_Formal (E))
+ then
+ declare
+ T : constant Entity_Id := Etype (First_Formal (E));
+ begin
+ if Is_Controlled (T) then
+ if Warnings_Off (T)
+ or else (Ekind (T) = E_Private_Type
+ and then Warnings_Off (Full_View (T)))
+ then
+ goto Output;
+ end if;
+ end if;
+ end;
+ end if;
+
+ -- Go ahead and give warning if not this special case
+
+ Error_Msg_NE
+ ("call to& may occur before body is seen<l<", N, Orig_Ent);
+ end if;
+
+ Error_Msg_N ("\Program_Error ]<l<", N);
+
+ -- There is no need to query the elaboration warning message flags
+ -- because the main message is an error, not a warning, therefore
+ -- all the clarification messages produces by Output_Calls must be
+ -- emitted unconditionally.
+
+ <<Output>>
+
+ Output_Calls (N, Check_Elab_Flag => False);
+ end if;
+ end if;
+ end Check_Internal_Call_Continue;
+
+ ---------------------------
+ -- Check_Task_Activation --
+ ---------------------------
+
+ procedure Check_Task_Activation (N : Node_Id) is
+ Loc : constant Source_Ptr := Sloc (N);
+ Inter_Procs : constant Elist_Id := New_Elmt_List;
+ Intra_Procs : constant Elist_Id := New_Elmt_List;
+ Ent : Entity_Id;
+ P : Entity_Id;
+ Task_Scope : Entity_Id;
+ Cunit_SC : Boolean := False;
+ Decl : Node_Id;
+ Elmt : Elmt_Id;
+ Enclosing : Entity_Id;
+
+ procedure Add_Task_Proc (Typ : Entity_Id);
+ -- Add to Task_Procs the task body procedure(s) of task types in Typ.
+ -- For record types, this procedure recurses over component types.
+
+ procedure Collect_Tasks (Decls : List_Id);
+ -- Collect the types of the tasks that are to be activated in the given
+ -- list of declarations, in order to perform elaboration checks on the
+ -- corresponding task procedures that are called implicitly here.
+
+ function Outer_Unit (E : Entity_Id) return Entity_Id;
+ -- find enclosing compilation unit of Entity, ignoring subunits, or
+ -- else enclosing subprogram. If E is not a package, there is no need
+ -- for inter-unit elaboration checks.
+
+ -------------------
+ -- Add_Task_Proc --
+ -------------------
+
+ procedure Add_Task_Proc (Typ : Entity_Id) is
+ Comp : Entity_Id;
+ Proc : Entity_Id := Empty;
+
+ begin
+ if Is_Task_Type (Typ) then
+ Proc := Get_Task_Body_Procedure (Typ);
+
+ elsif Is_Array_Type (Typ)
+ and then Has_Task (Base_Type (Typ))
+ then
+ Add_Task_Proc (Component_Type (Typ));
+
+ elsif Is_Record_Type (Typ)
+ and then Has_Task (Base_Type (Typ))
+ then
+ Comp := First_Component (Typ);
+ while Present (Comp) loop
+ Add_Task_Proc (Etype (Comp));
+ Comp := Next_Component (Comp);
+ end loop;
+ end if;
+
+ -- If the task type is another unit, we will perform the usual
+ -- elaboration check on its enclosing unit. If the type is in the
+ -- same unit, we can trace the task body as for an internal call,
+ -- but we only need to examine other external calls, because at
+ -- the point the task is activated, internal subprogram bodies
+ -- will have been elaborated already. We keep separate lists for
+ -- each kind of task.
+
+ -- Skip this test if errors have occurred, since in this case
+ -- we can get false indications.
+
+ if Serious_Errors_Detected /= 0 then
+ return;
+ end if;
+
+ if Present (Proc) then
+ if Outer_Unit (Scope (Proc)) = Enclosing then
+
+ if No (Corresponding_Body (Unit_Declaration_Node (Proc)))
+ and then
+ (not Is_Generic_Instance (Scope (Proc))
+ or else Scope (Proc) = Scope (Defining_Identifier (Decl)))
+ then
+ Error_Msg_Warn := SPARK_Mode /= On;
+ Error_Msg_N
+ ("task will be activated before elaboration of its body<<",
+ Decl);
+ Error_Msg_N ("\Program_Error [<<", Decl);
+
+ elsif Present
+ (Corresponding_Body (Unit_Declaration_Node (Proc)))
+ then
+ Append_Elmt (Proc, Intra_Procs);
+ end if;
+
+ else
+ -- No need for multiple entries of the same type
+
+ Elmt := First_Elmt (Inter_Procs);
+ while Present (Elmt) loop
+ if Node (Elmt) = Proc then
+ return;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ Append_Elmt (Proc, Inter_Procs);
+ end if;
+ end if;
+ end Add_Task_Proc;
+
+ -------------------
+ -- Collect_Tasks --
+ -------------------
+
+ procedure Collect_Tasks (Decls : List_Id) is
+ begin
+ if Present (Decls) then
+ Decl := First (Decls);
+ while Present (Decl) loop
+ if Nkind (Decl) = N_Object_Declaration
+ and then Has_Task (Etype (Defining_Identifier (Decl)))
+ then
+ Add_Task_Proc (Etype (Defining_Identifier (Decl)));
+ end if;
+
+ Next (Decl);
+ end loop;
+ end if;
+ end Collect_Tasks;
+
+ ----------------
+ -- Outer_Unit --
+ ----------------
+
+ function Outer_Unit (E : Entity_Id) return Entity_Id is
+ Outer : Entity_Id;
+
+ begin
+ Outer := E;
+ while Present (Outer) loop
+ if Elaboration_Checks_Suppressed (Outer) then
+ Cunit_SC := True;
+ end if;
+
+ exit when Is_Child_Unit (Outer)
+ or else Scope (Outer) = Standard_Standard
+ or else Ekind (Outer) /= E_Package;
+ Outer := Scope (Outer);
+ end loop;
+
+ return Outer;
+ end Outer_Unit;
+
+ -- Start of processing for Check_Task_Activation
+
+ begin
+ pragma Assert (Legacy_Elaboration_Checks);
+
+ Enclosing := Outer_Unit (Current_Scope);
+
+ -- Find all tasks declared in the current unit
+
+ if Nkind (N) = N_Package_Body then
+ P := Unit_Declaration_Node (Corresponding_Spec (N));
+
+ Collect_Tasks (Declarations (N));
+ Collect_Tasks (Visible_Declarations (Specification (P)));
+ Collect_Tasks (Private_Declarations (Specification (P)));
+
+ elsif Nkind (N) = N_Package_Declaration then
+ Collect_Tasks (Visible_Declarations (Specification (N)));
+ Collect_Tasks (Private_Declarations (Specification (N)));
+
+ else
+ Collect_Tasks (Declarations (N));
+ end if;
+
+ -- We only perform detailed checks in all tasks that are library level
+ -- entities. If the master is a subprogram or task, activation will
+ -- depend on the activation of the master itself.
+
+ -- Should dynamic checks be added in the more general case???
+
+ if Ekind (Enclosing) /= E_Package then
+ return;
+ end if;
+
+ -- For task types defined in other units, we want the unit containing
+ -- the task body to be elaborated before the current one.
+
+ Elmt := First_Elmt (Inter_Procs);
+ while Present (Elmt) loop
+ Ent := Node (Elmt);
+ Task_Scope := Outer_Unit (Scope (Ent));
+
+ if not Is_Compilation_Unit (Task_Scope) then
+ null;
+
+ elsif Suppress_Elaboration_Warnings (Task_Scope)
+ or else Elaboration_Checks_Suppressed (Task_Scope)
+ then
+ null;
+
+ elsif Dynamic_Elaboration_Checks then
+ if not Elaboration_Checks_Suppressed (Ent)
+ and then not Cunit_SC
+ and then not Restriction_Active
+ (No_Entry_Calls_In_Elaboration_Code)
+ then
+ -- Runtime elaboration check required. Generate check of the
+ -- elaboration counter for the unit containing the entity.
+
+ Insert_Elab_Check (N,
+ Make_Attribute_Reference (Loc,
+ Prefix =>
+ New_Occurrence_Of (Spec_Entity (Task_Scope), Loc),
+ Attribute_Name => Name_Elaborated));
+ end if;
+
+ else
+ -- Force the binder to elaborate other unit first
+
+ if Elab_Info_Messages
+ and then not Suppress_Elaboration_Warnings (Ent)
+ and then not Elaboration_Checks_Suppressed (Ent)
+ and then not Suppress_Elaboration_Warnings (Task_Scope)
+ and then not Elaboration_Checks_Suppressed (Task_Scope)
+ then
+ Error_Msg_Node_2 := Task_Scope;
+ Error_Msg_NE
+ ("info: activation of an instance of task type & requires "
+ & "pragma Elaborate_All on &?$?", N, Ent);
+ end if;
+
+ Activate_Elaborate_All_Desirable (N, Task_Scope);
+ Set_Suppress_Elaboration_Warnings (Task_Scope);
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ -- For tasks declared in the current unit, trace other calls within the
+ -- task procedure bodies, which are available.
+
+ if not Debug_Flag_Dot_Y then
+ In_Task_Activation := True;
+
+ Elmt := First_Elmt (Intra_Procs);
+ while Present (Elmt) loop
+ Ent := Node (Elmt);
+ Check_Internal_Call_Continue (N, Ent, Enclosing, Ent);
+ Next_Elmt (Elmt);
+ end loop;
+
+ In_Task_Activation := False;
+ end if;
+ end Check_Task_Activation;
+
+ ------------------------
+ -- Get_Referenced_Ent --
+ ------------------------
+
+ function Get_Referenced_Ent (N : Node_Id) return Entity_Id is
+ Nam : Node_Id;
+
+ begin
+ if Nkind (N) in N_Has_Entity
+ and then Present (Entity (N))
+ and then Ekind (Entity (N)) = E_Variable
+ then
+ return Entity (N);
+ end if;
+
+ if Nkind (N) = N_Attribute_Reference then
+ Nam := Prefix (N);
+ else
+ Nam := Name (N);
+ end if;
+
+ if No (Nam) then
+ return Empty;
+ elsif Nkind (Nam) = N_Selected_Component then
+ return Entity (Selector_Name (Nam));
+ elsif not Is_Entity_Name (Nam) then
+ return Empty;
+ else
+ return Entity (Nam);
+ end if;
+ end Get_Referenced_Ent;
+
+ ----------------------
+ -- Has_Generic_Body --
+ ----------------------
+
+ function Has_Generic_Body (N : Node_Id) return Boolean is
+ Ent : constant Entity_Id := Get_Generic_Entity (N);
+ Decl : constant Node_Id := Unit_Declaration_Node (Ent);
+ Scop : Entity_Id;
+
+ function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id;
+ -- Determine if the list of nodes headed by N and linked by Next
+ -- contains a package body for the package spec entity E, and if so
+ -- return the package body. If not, then returns Empty.
+
+ function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id;
+ -- This procedure is called load the unit whose name is given by Nam.
+ -- This unit is being loaded to see whether it contains an optional
+ -- generic body. The returned value is the loaded unit, which is always
+ -- a package body (only package bodies can contain other entities in the
+ -- sense in which Has_Generic_Body is interested). We only attempt to
+ -- load bodies if we are generating code. If we are in semantics check
+ -- only mode, then it would be wrong to load bodies that are not
+ -- required from a semantic point of view, so in this case we return
+ -- Empty. The result is that the caller may incorrectly decide that a
+ -- generic spec does not have a body when in fact it does, but the only
+ -- harm in this is that some warnings on elaboration problems may be
+ -- lost in semantic checks only mode, which is not big loss. We also
+ -- return Empty if we go for a body and it is not there.
+
+ function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id;
+ -- PE is the entity for a package spec. This function locates the
+ -- corresponding package body, returning Empty if none is found. The
+ -- package body returned is fully parsed but may not yet be analyzed,
+ -- so only syntactic fields should be referenced.
+
+ ------------------
+ -- Find_Body_In --
+ ------------------
+
+ function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id is
+ Nod : Node_Id;
+
+ begin
+ Nod := N;
+ while Present (Nod) loop
+
+ -- If we found the package body we are looking for, return it
+
+ if Nkind (Nod) = N_Package_Body
+ and then Chars (Defining_Unit_Name (Nod)) = Chars (E)
+ then
+ return Nod;
+
+ -- If we found the stub for the body, go after the subunit,
+ -- loading it if necessary.
+
+ elsif Nkind (Nod) = N_Package_Body_Stub
+ and then Chars (Defining_Identifier (Nod)) = Chars (E)
+ then
+ if Present (Library_Unit (Nod)) then
+ return Unit (Library_Unit (Nod));
+
+ else
+ return Load_Package_Body (Get_Unit_Name (Nod));
+ end if;
+
+ -- If neither package body nor stub, keep looking on chain
+
+ else
+ Next (Nod);
+ end if;
+ end loop;
+
+ return Empty;
+ end Find_Body_In;
+
+ -----------------------
+ -- Load_Package_Body --
+ -----------------------
+
+ function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id is
+ U : Unit_Number_Type;
+
+ begin
+ if Operating_Mode /= Generate_Code then
+ return Empty;
+ else
+ U :=
+ Load_Unit
+ (Load_Name => Nam,
+ Required => False,
+ Subunit => False,
+ Error_Node => N);
+
+ if U = No_Unit then
+ return Empty;
+ else
+ return Unit (Cunit (U));
+ end if;
+ end if;
+ end Load_Package_Body;
+
+ -------------------------------
+ -- Locate_Corresponding_Body --
+ -------------------------------
+
+ function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id is
+ Spec : constant Node_Id := Declaration_Node (PE);
+ Decl : constant Node_Id := Parent (Spec);
+ Scop : constant Entity_Id := Scope (PE);
+ PBody : Node_Id;
+
+ begin
+ if Is_Library_Level_Entity (PE) then
+
+ -- If package is a library unit that requires a body, we have no
+ -- choice but to go after that body because it might contain an
+ -- optional body for the original generic package.
+
+ if Unit_Requires_Body (PE) then
+
+ -- Load the body. Note that we are a little careful here to use
+ -- Spec to get the unit number, rather than PE or Decl, since
+ -- in the case where the package is itself a library level
+ -- instantiation, Spec will properly reference the generic
+ -- template, which is what we really want.
+
+ return
+ Load_Package_Body
+ (Get_Body_Name (Unit_Name (Get_Source_Unit (Spec))));
+
+ -- But if the package is a library unit that does NOT require
+ -- a body, then no body is permitted, so we are sure that there
+ -- is no body for the original generic package.
+
+ else
+ return Empty;
+ end if;
+
+ -- Otherwise look and see if we are embedded in a further package
+
+ elsif Is_Package_Or_Generic_Package (Scop) then
+
+ -- If so, get the body of the enclosing package, and look in
+ -- its package body for the package body we are looking for.
+
+ PBody := Locate_Corresponding_Body (Scop);
+
+ if No (PBody) then
+ return Empty;
+ else
+ return Find_Body_In (PE, First (Declarations (PBody)));
+ end if;
+
+ -- If we are not embedded in a further package, then the body
+ -- must be in the same declarative part as we are.
+
+ else
+ return Find_Body_In (PE, Next (Decl));
+ end if;
+ end Locate_Corresponding_Body;
+
+ -- Start of processing for Has_Generic_Body
+
+ begin
+ if Present (Corresponding_Body (Decl)) then
+ return True;
+
+ elsif Unit_Requires_Body (Ent) then
+ return True;
+
+ -- Compilation units cannot have optional bodies
+
+ elsif Is_Compilation_Unit (Ent) then
+ return False;
+
+ -- Otherwise look at what scope we are in
+
+ else
+ Scop := Scope (Ent);
+
+ -- Case of entity is in other than a package spec, in this case
+ -- the body, if present, must be in the same declarative part.
+
+ if not Is_Package_Or_Generic_Package (Scop) then
+ declare
+ P : Node_Id;
+
+ begin
+ -- Declaration node may get us a spec, so if so, go to
+ -- the parent declaration.
+
+ P := Declaration_Node (Ent);
+ while not Is_List_Member (P) loop
+ P := Parent (P);
+ end loop;
+
+ return Present (Find_Body_In (Ent, Next (P)));
+ end;
+
+ -- If the entity is in a package spec, then we have to locate
+ -- the corresponding package body, and look there.
+
+ else
+ declare
+ PBody : constant Node_Id := Locate_Corresponding_Body (Scop);
+
+ begin
+ if No (PBody) then
+ return False;
+ else
+ return
+ Present
+ (Find_Body_In (Ent, (First (Declarations (PBody)))));
+ end if;
+ end;
+ end if;
+ end if;
+ end Has_Generic_Body;
+
+ -----------------------
+ -- Insert_Elab_Check --
+ -----------------------
+
+ procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty) is
+ Nod : Node_Id;
+ Loc : constant Source_Ptr := Sloc (N);
+
+ Chk : Node_Id;
+ -- The check (N_Raise_Program_Error) node to be inserted
+
+ begin
+ -- If expansion is disabled, do not generate any checks. Also
+ -- skip checks if any subunits are missing because in either
+ -- case we lack the full information that we need, and no object
+ -- file will be created in any case.
+
+ if not Expander_Active or else Subunits_Missing then
+ return;
+ end if;
+
+ -- If we have a generic instantiation, where Instance_Spec is set,
+ -- then this field points to a generic instance spec that has
+ -- been inserted before the instantiation node itself, so that
+ -- is where we want to insert a check.
+
+ if Nkind (N) in N_Generic_Instantiation
+ and then Present (Instance_Spec (N))
+ then
+ Nod := Instance_Spec (N);
+ else
+ Nod := N;
+ end if;
+
+ -- Build check node, possibly with condition
+
+ Chk :=
+ Make_Raise_Program_Error (Loc, Reason => PE_Access_Before_Elaboration);
+
+ if Present (C) then
+ Set_Condition (Chk, Make_Op_Not (Loc, Right_Opnd => C));
+ end if;
+
+ -- If we are inserting at the top level, insert in Aux_Decls
+
+ if Nkind (Parent (Nod)) = N_Compilation_Unit then
+ declare
+ ADN : constant Node_Id := Aux_Decls_Node (Parent (Nod));
+
+ begin
+ if No (Declarations (ADN)) then
+ Set_Declarations (ADN, New_List (Chk));
+ else
+ Append_To (Declarations (ADN), Chk);
+ end if;
+
+ Analyze (Chk);
+ end;
+
+ -- Otherwise just insert as an action on the node in question
+
+ else
+ Insert_Action (Nod, Chk);
+ end if;
+ end Insert_Elab_Check;
+
+ -------------------------------
+ -- Is_Call_Of_Generic_Formal --
+ -------------------------------
+
+ function Is_Call_Of_Generic_Formal (N : Node_Id) return Boolean is
+ begin
+ return Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement)
+
+ -- Always return False if debug flag -gnatd.G is set
+
+ and then not Debug_Flag_Dot_GG
+
+ -- For now, we detect this by looking for the strange identifier
+ -- node, whose Chars reflect the name of the generic formal, but
+ -- the Chars of the Entity references the generic actual.
+
+ and then Nkind (Name (N)) = N_Identifier
+ and then Chars (Name (N)) /= Chars (Entity (Name (N)));
+ end Is_Call_Of_Generic_Formal;
+
+ -------------------------------
+ -- Is_Finalization_Procedure --
+ -------------------------------
+
+ function Is_Finalization_Procedure (Id : Entity_Id) return Boolean is
+ begin
+ -- Check whether Id is a procedure with at least one parameter
+
+ if Ekind (Id) = E_Procedure and then Present (First_Formal (Id)) then
+ declare
+ Typ : constant Entity_Id := Etype (First_Formal (Id));
+ Deep_Fin : Entity_Id := Empty;
+ Fin : Entity_Id := Empty;
+
+ begin
+ -- If the type of the first formal does not require finalization
+ -- actions, then this is definitely not [Deep_]Finalize.
+
+ if not Needs_Finalization (Typ) then
+ return False;
+ end if;
+
+ -- At this point we have the following scenario:
+
+ -- procedure Name (Param1 : [in] [out] Ctrl[; Param2 : ...]);
+
+ -- Recover the two possible versions of [Deep_]Finalize using the
+ -- type of the first parameter and compare with the input.
+
+ Deep_Fin := TSS (Typ, TSS_Deep_Finalize);
+
+ if Is_Controlled (Typ) then
+ Fin := Find_Prim_Op (Typ, Name_Finalize);
+ end if;
+
+ return (Present (Deep_Fin) and then Id = Deep_Fin)
+ or else (Present (Fin) and then Id = Fin);
+ end;
+ end if;
+
+ return False;
+ end Is_Finalization_Procedure;
+
+ ------------------
+ -- Output_Calls --
+ ------------------
+
+ procedure Output_Calls
+ (N : Node_Id;
+ Check_Elab_Flag : Boolean)
+ is
+ function Emit (Flag : Boolean) return Boolean;
+ -- Determine whether to emit an error message based on the combination
+ -- of flags Check_Elab_Flag and Flag.
+
+ function Is_Printable_Error_Name return Boolean;
+ -- An internal function, used to determine if a name, stored in the
+ -- Name_Buffer, is either a non-internal name, or is an internal name
+ -- that is printable by the error message circuits (i.e. it has a single
+ -- upper case letter at the end).
+
+ ----------
+ -- Emit --
+ ----------
+
+ function Emit (Flag : Boolean) return Boolean is
+ begin
+ if Check_Elab_Flag then
+ return Flag;
+ else
+ return True;
+ end if;
+ end Emit;
+
+ -----------------------------
+ -- Is_Printable_Error_Name --
+ -----------------------------
+
+ function Is_Printable_Error_Name return Boolean is
+ begin
+ if not Is_Internal_Name then
+ return True;
+
+ elsif Name_Len = 1 then
+ return False;
+
+ else
+ Name_Len := Name_Len - 1;
+ return not Is_Internal_Name;
+ end if;
+ end Is_Printable_Error_Name;
+
+ -- Local variables
+
+ Ent : Entity_Id;
+
+ -- Start of processing for Output_Calls
+
+ begin
+ for J in reverse 1 .. Elab_Call.Last loop
+ Error_Msg_Sloc := Elab_Call.Table (J).Cloc;
+
+ Ent := Elab_Call.Table (J).Ent;
+ Get_Name_String (Chars (Ent));
+
+ -- Dynamic elaboration model, warnings controlled by -gnatwl
+
+ if Dynamic_Elaboration_Checks then
+ if Emit (Elab_Warnings) then
+ if Is_Generic_Unit (Ent) then
+ Error_Msg_NE ("\\?l?& instantiated #", N, Ent);
+ elsif Is_Init_Proc (Ent) then
+ Error_Msg_N ("\\?l?initialization procedure called #", N);
+ elsif Is_Printable_Error_Name then
+ Error_Msg_NE ("\\?l?& called #", N, Ent);
+ else
+ Error_Msg_N ("\\?l?called #", N);
+ end if;
+ end if;
+
+ -- Static elaboration model, info messages controlled by -gnatel
+
+ else
+ if Emit (Elab_Info_Messages) then
+ if Is_Generic_Unit (Ent) then
+ Error_Msg_NE ("\\?$?& instantiated #", N, Ent);
+ elsif Is_Init_Proc (Ent) then
+ Error_Msg_N ("\\?$?initialization procedure called #", N);
+ elsif Is_Printable_Error_Name then
+ Error_Msg_NE ("\\?$?& called #", N, Ent);
+ else
+ Error_Msg_N ("\\?$?called #", N);
+ end if;
+ end if;
+ end if;
+ end loop;
+ end Output_Calls;
+
+ ----------------------------
+ -- Same_Elaboration_Scope --
+ ----------------------------
+
+ function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean is
+ S1 : Entity_Id;
+ S2 : Entity_Id;
+
+ begin
+ -- Find elaboration scope for Scop1
+ -- This is either a subprogram or a compilation unit.
+
+ S1 := Scop1;
+ while S1 /= Standard_Standard
+ and then not Is_Compilation_Unit (S1)
+ and then Ekind_In (S1, E_Package, E_Protected_Type, E_Block)
+ loop
+ S1 := Scope (S1);
+ end loop;
+
+ -- Find elaboration scope for Scop2
+
+ S2 := Scop2;
+ while S2 /= Standard_Standard
+ and then not Is_Compilation_Unit (S2)
+ and then Ekind_In (S2, E_Package, E_Protected_Type, E_Block)
+ loop
+ S2 := Scope (S2);
+ end loop;
+
+ return S1 = S2;
+ end Same_Elaboration_Scope;
+
+ -----------------
+ -- Set_C_Scope --
+ -----------------
+
+ procedure Set_C_Scope is
+ begin
+ while not Is_Compilation_Unit (C_Scope) loop
+ C_Scope := Scope (C_Scope);
+ end loop;
+ end Set_C_Scope;
+
+ --------------------------------
+ -- Set_Elaboration_Constraint --
+ --------------------------------
+
+ procedure Set_Elaboration_Constraint
+ (Call : Node_Id;
+ Subp : Entity_Id;
+ Scop : Entity_Id)
+ is
+ Elab_Unit : Entity_Id;
+
+ -- Check whether this is a call to an Initialize subprogram for a
+ -- controlled type. Note that Call can also be a 'Access attribute
+ -- reference, which now generates an elaboration check.
+
+ Init_Call : constant Boolean :=
+ Nkind (Call) = N_Procedure_Call_Statement
+ and then Chars (Subp) = Name_Initialize
+ and then Comes_From_Source (Subp)
+ and then Present (Parameter_Associations (Call))
+ and then Is_Controlled (Etype (First_Actual (Call)));
+
+ begin
+ -- If the unit is mentioned in a with_clause of the current unit, it is
+ -- visible, and we can set the elaboration flag.
+
+ if Is_Immediately_Visible (Scop)
+ or else (Is_Child_Unit (Scop) and then Is_Visible_Lib_Unit (Scop))
+ then
+ Activate_Elaborate_All_Desirable (Call, Scop);
+ Set_Suppress_Elaboration_Warnings (Scop);
+ return;
+ end if;
+
+ -- If this is not an initialization call or a call using object notation
+ -- we know that the unit of the called entity is in the context, and we
+ -- can set the flag as well. The unit need not be visible if the call
+ -- occurs within an instantiation.
+
+ if Is_Init_Proc (Subp)
+ or else Init_Call
+ or else Nkind (Original_Node (Call)) = N_Selected_Component
+ then
+ null; -- detailed processing follows.
+
+ else
+ Activate_Elaborate_All_Desirable (Call, Scop);
+ Set_Suppress_Elaboration_Warnings (Scop);
+ return;
+ end if;
+
+ -- If the unit is not in the context, there must be an intermediate unit
+ -- that is, on which we need to place to elaboration flag. This happens
+ -- with init proc calls.
+
+ if Is_Init_Proc (Subp) or else Init_Call then
+
+ -- The initialization call is on an object whose type is not declared
+ -- in the same scope as the subprogram. The type of the object must
+ -- be a subtype of the type of operation. This object is the first
+ -- actual in the call.
+
+ declare
+ Typ : constant Entity_Id :=
+ Etype (First (Parameter_Associations (Call)));
+ begin
+ Elab_Unit := Scope (Typ);
+ while (Present (Elab_Unit))
+ and then not Is_Compilation_Unit (Elab_Unit)
+ loop
+ Elab_Unit := Scope (Elab_Unit);
+ end loop;
+ end;
+
+ -- If original node uses selected component notation, the prefix is
+ -- visible and determines the scope that must be elaborated. After
+ -- rewriting, the prefix is the first actual in the call.
+
+ elsif Nkind (Original_Node (Call)) = N_Selected_Component then
+ Elab_Unit := Scope (Etype (First (Parameter_Associations (Call))));
+
+ -- Not one of special cases above
+
+ else
+ -- Using previously computed scope. If the elaboration check is
+ -- done after analysis, the scope is not visible any longer, but
+ -- must still be in the context.
+
+ Elab_Unit := Scop;
+ end if;
+
+ Activate_Elaborate_All_Desirable (Call, Elab_Unit);
+ Set_Suppress_Elaboration_Warnings (Elab_Unit);
+ end Set_Elaboration_Constraint;
+
+ -----------------
+ -- Spec_Entity --
+ -----------------
+
+ function Spec_Entity (E : Entity_Id) return Entity_Id is
+ Decl : Node_Id;
+
+ begin
+ -- Check for case of body entity
+ -- Why is the check for E_Void needed???
+
+ if Ekind_In (E, E_Void, E_Subprogram_Body, E_Package_Body) then
+ Decl := E;
+
+ loop
+ Decl := Parent (Decl);
+ exit when Nkind (Decl) in N_Proper_Body;
+ end loop;
+
+ return Corresponding_Spec (Decl);
+
+ else
+ return E;
+ end if;
+ end Spec_Entity;
+
+ ------------
+ -- Within --
+ ------------
+
+ function Within (E1, E2 : Entity_Id) return Boolean is
+ Scop : Entity_Id;
+ begin
+ Scop := E1;
+ loop
+ if Scop = E2 then
+ return True;
+ elsif Scop = Standard_Standard then
+ return False;
+ else
+ Scop := Scope (Scop);
+ end if;
+ end loop;
+ end Within;
+
+ --------------------------
+ -- Within_Elaborate_All --
+ --------------------------
+
+ function Within_Elaborate_All
+ (Unit : Unit_Number_Type;
+ E : Entity_Id) return Boolean
+ is
+ type Unit_Number_Set is array (Main_Unit .. Last_Unit) of Boolean;
+ pragma Pack (Unit_Number_Set);
+
+ Seen : Unit_Number_Set := (others => False);
+ -- Seen (X) is True after we have seen unit X in the walk. This is used
+ -- to prevent processing the same unit more than once.
+
+ Result : Boolean := False;
+
+ procedure Helper (Unit : Unit_Number_Type);
+ -- This helper procedure does all the work for Within_Elaborate_All. It
+ -- walks the dependency graph, and sets Result to True if it finds an
+ -- appropriate Elaborate_All.
+
+ ------------
+ -- Helper --
+ ------------
+
+ procedure Helper (Unit : Unit_Number_Type) is
+ CU : constant Node_Id := Cunit (Unit);
+
+ Item : Node_Id;
+ Item2 : Node_Id;
+ Elab_Id : Entity_Id;
+ Par : Node_Id;
+
+ begin
+ if Seen (Unit) then
+ return;
+ else
+ Seen (Unit) := True;
+ end if;
+
+ -- First, check for Elaborate_Alls on this unit
+
+ Item := First (Context_Items (CU));
+ while Present (Item) loop
+ if Nkind (Item) = N_Pragma
+ and then Pragma_Name (Item) = Name_Elaborate_All
+ then
+ -- Return if some previous error on the pragma itself. The
+ -- pragma may be unanalyzed, because of a previous error, or
+ -- if it is the context of a subunit, inherited by its parent.
+
+ if Error_Posted (Item) or else not Analyzed (Item) then
+ return;
+ end if;
+
+ Elab_Id :=
+ Entity
+ (Expression (First (Pragma_Argument_Associations (Item))));
+
+ if E = Elab_Id then
+ Result := True;
+ return;
+ end if;
+
+ Par := Parent (Unit_Declaration_Node (Elab_Id));
+
+ Item2 := First (Context_Items (Par));
+ while Present (Item2) loop
+ if Nkind (Item2) = N_With_Clause
+ and then Entity (Name (Item2)) = E
+ and then not Limited_Present (Item2)
+ then
+ Result := True;
+ return;
+ end if;
+
+ Next (Item2);
+ end loop;
+ end if;
+
+ Next (Item);
+ end loop;
+
+ -- Second, recurse on with's. We could do this as part of the above
+ -- loop, but it's probably more efficient to have two loops, because
+ -- the relevant Elaborate_All is likely to be on the initial unit. In
+ -- other words, we're walking the with's breadth-first. This part is
+ -- only necessary in the dynamic elaboration model.
+
+ if Dynamic_Elaboration_Checks then
+ Item := First (Context_Items (CU));
+ while Present (Item) loop
+ if Nkind (Item) = N_With_Clause
+ and then not Limited_Present (Item)
+ then
+ -- Note: the following call to Get_Cunit_Unit_Number does a
+ -- linear search, which could be slow, but it's OK because
+ -- we're about to give a warning anyway. Also, there might
+ -- be hundreds of units, but not millions. If it turns out
+ -- to be a problem, we could store the Get_Cunit_Unit_Number
+ -- in each N_Compilation_Unit node, but that would involve
+ -- rearranging N_Compilation_Unit_Aux to make room.
+
+ Helper (Get_Cunit_Unit_Number (Library_Unit (Item)));
+
+ if Result then
+ return;
+ end if;
+ end if;
+
+ Next (Item);
+ end loop;
+ end if;
+ end Helper;
+
+ -- Start of processing for Within_Elaborate_All
+
+ begin
+ Helper (Unit);
+ return Result;
+ end Within_Elaborate_All;
+
end Sem_Elab;
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