-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2008, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- been any other errors, we just ignore it, otherwise it is
-- a real internal error which we complain about.
+ -- We must also consider the case of call to a runtime function
+ -- that is not available in the configurable runtime.
+
when N_Empty =>
- pragma Assert (Serious_Errors_Detected /= 0);
+ pragma Assert (Serious_Errors_Detected /= 0
+ or else Configurable_Run_Time_Violations /= 0);
null;
-- A call to analyze the error node is simply ignored, to avoid
-- values for these variables, and also that such calls do not
-- disturb the settings for units being analyzed at a higher level.
+ S_Current_Sem_Unit : constant Unit_Number_Type := Current_Sem_Unit;
S_Full_Analysis : constant Boolean := Full_Analysis;
- S_In_Default_Expr : constant Boolean := In_Default_Expression;
+ S_GNAT_Mode : constant Boolean := GNAT_Mode;
+ S_Global_Dis_Names : constant Boolean := Global_Discard_Names;
+ S_In_Spec_Expr : constant Boolean := In_Spec_Expression;
S_Inside_A_Generic : constant Boolean := Inside_A_Generic;
S_New_Nodes_OK : constant Int := New_Nodes_OK;
S_Outer_Gen_Scope : constant Entity_Id := Outer_Generic_Scope;
- S_Sem_Unit : constant Unit_Number_Type := Current_Sem_Unit;
- S_GNAT_Mode : constant Boolean := GNAT_Mode;
- S_Discard_Names : constant Boolean := Global_Discard_Names;
Generic_Main : constant Boolean :=
Nkind (Unit (Cunit (Main_Unit)))
(Operating_Mode = Generate_Code or Debug_Flag_X);
end if;
- Full_Analysis := True;
- Inside_A_Generic := False;
- In_Default_Expression := False;
+ Full_Analysis := True;
+ Inside_A_Generic := False;
+ In_Spec_Expression := False;
Set_Comes_From_Source_Default (False);
Save_Opt_Config_Switches (Save_Config_Switches);
-- Restore settings of saved switches to entry values
- Current_Sem_Unit := S_Sem_Unit;
- Full_Analysis := S_Full_Analysis;
- In_Default_Expression := S_In_Default_Expr;
- Inside_A_Generic := S_Inside_A_Generic;
- New_Nodes_OK := S_New_Nodes_OK;
- Outer_Generic_Scope := S_Outer_Gen_Scope;
- GNAT_Mode := S_GNAT_Mode;
- Global_Discard_Names := S_Discard_Names;
+ Current_Sem_Unit := S_Current_Sem_Unit;
+ Full_Analysis := S_Full_Analysis;
+ Global_Discard_Names := S_Global_Dis_Names;
+ GNAT_Mode := S_GNAT_Mode;
+ In_Spec_Expression := S_In_Spec_Expr;
+ Inside_A_Generic := S_Inside_A_Generic;
+ New_Nodes_OK := S_New_Nodes_OK;
+ Outer_Generic_Scope := S_Outer_Gen_Scope;
Restore_Opt_Config_Switches (Save_Config_Switches);
Expander_Mode_Restore;
-
end Semantics;
end Sem;
-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2008, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- Analysis-Resolution-Expansion model for expressions. The most prominent
-- examples are the handling of default expressions and aggregates.
-----------------------------------------------------
--- Handling of Default and Per-Object Expressions --
-----------------------------------------------------
+-----------------------------------------------------------------------
+-- Handling of Default and Per-Object Expressions (Spec-Expressions) --
+-----------------------------------------------------------------------
-- The default expressions in component declarations and in procedure
--- specifications (but not the ones in object declarations) are quite
--- tricky to handle. The problem is that some processing is required
--- at the point where the expression appears:
+-- specifications (but not the ones in object declarations) are quite tricky
+-- to handle. The problem is that some processing is required at the point
+-- where the expression appears:
-- visibility analysis (including user defined operators)
-- freezing of static expressions
--- but other processing must be deferred until the enclosing entity
--- (record or procedure specification) is frozen:
+-- but other processing must be deferred until the enclosing entity (record or
+-- procedure specification) is frozen:
--- freezing of any other types in the expression
--- expansion
+-- freezing of any other types in the expression expansion
+-- generation of code
-- A similar situation occurs with the argument of priority and interrupt
-- priority pragmas that appear in task and protected definition specs and
-- other cases of per-object expressions (see RM 3.8(18)).
--- Expansion has to be deferred since you can't generate code for
--- expressions that refernce types that have not been frozen yet. As an
--- example, consider the following:
+-- Another similar case is the conditions in precondition and postcondition
+-- pragmas that appear with subprogram specifications rather than in the body.
+
+-- Collectively we call these Spec_Expressions. The routine that performs the
+-- special analysis is called Analyze_Spec_Expression.
+
+-- Expansion has to be deferred since you can't generate code for expressions
+-- that reference types that have not been frozen yet. As an example, consider
+-- the following:
-- type x is delta 0.5 range -10.0 .. +10.0;
-- ...
-- for x'small use 0.25
--- The expander is in charge of dealing with fixed-point, and of course
--- the small declaration, which is not too late, since the declaration of
--- type q does *not* freeze type x, definitely affects the expanded code.
+-- The expander is in charge of dealing with fixed-point, and of course the
+-- small declaration, which is not too late, since the declaration of type q
+-- does *not* freeze type x, definitely affects the expanded code.
-- Another reason that we cannot expand early is that expansion can generate
-- range checks. These range checks need to be inserted not at the point of
-- this is the one case where this model falls down. Here is how we patch
-- it up without causing too much distortion to our basic model.
--- A switch (sede below) is set to indicate that we are in the initial
+-- A switch (In_Spec_Expression) is set to show that we are in the initial
-- occurence of a default expression. The analyzer is then called on this
--- expression with the switch set true. Analysis and resolution proceed
--- almost as usual, except that Freeze_Expression will not freeze
--- non-static expressions if this switch is set, and the call to Expand at
--- the end of resolution is skipped. This also skips the code that normally
--- sets the Analyzed flag to True). The result is that when we are done the
--- tree is still marked as unanalyzed, but all types for static expressions
--- are frozen as required, and all entities of variables have been
--- recorded. We then turn off the switch, and later on reanalyze the
--- expression with the switch off. The effect is that this second analysis
--- freezes the rest of the types as required, and generates code but
--- visibility analysis is not repeated since all the entities are marked.
+-- expression with the switch set true. Analysis and resolution proceed almost
+-- as usual, except that Freeze_Expression will not freeze non-static
+-- expressions if this switch is set, and the call to Expand at the end of
+-- resolution is skipped. This also skips the code that normally sets the
+-- Analyzed flag to True. The result is that when we are done the tree is
+-- still marked as unanalyzed, but all types for static expressions are frozen
+-- as required, and all entities of variables have been recorded. We then turn
+-- off the switch, and later on reanalyze the expression with the switch off.
+-- The effect is that this second analysis freezes the rest of the types as
+-- required, and generates code but visibility analysis is not repeated since
+-- all the entities are marked.
-- The second analysis (the one that generates code) is in the context
--- where the code is required. For a record field default, this is in
--- the initialization procedure for the record and for a subprogram
--- default parameter, it is at the point the subprogram is frozen.
--- For a priority or storage size pragma it is in the context of the
--- Init_Proc for the task or protected object.
+-- where the code is required. For a record field default, this is in the
+-- initialization procedure for the record and for a subprogram default
+-- parameter, it is at the point the subprogram is frozen. For a priority or
+-- storage size pragma it is in the context of the Init_Proc for the task or
+-- protected object. For a pre/postcondition pragma it is in the body when
+-- code for the pragma is generated.
------------------
-- Pre-Analysis --
--
-- (1 .. 100 => new Thing (Function_Call))
--
--- The normal Analysis-Resolution-Expansion mechanism where expansion
--- of the children is performed before expansion of the parent does not
--- work if the code generated for the children by the expander needs
--- to be evaluated repeatdly (for instance in the above aggregate
--- "new Thing (Function_Call)" needs to be called 100 times.)
--- The reason why this mecanism does not work is that, the expanded code
--- for the children is typically inserted above the parent and thus
--- when the father gets expanded no re-evaluation takes place. For instance
--- in the case of aggregates if "new Thing (Function_Call)" is expanded
--- before of the aggregate the expanded code will be placed outside
--- of the aggregate and when expanding the aggregate the loop from 1 to 100
--- will not surround the expanded code for "new Thing (Function_Call)".
---
--- To remedy this situation we introduce a new flag which signals whether
--- we want a full analysis (ie expansion is enabled) or a pre-analysis
--- which performs Analysis and Resolution but no expansion.
---
--- After the complete pre-analysis of an expression has been carried out
--- we can transform the expression and then carry out the full
--- Analyze-Resolve-Expand cycle on the transformed expression top-down
--- so that the expansion of inner expressions happens inside the newly
--- generated node for the parent expression.
---
+-- The normal Analysis-Resolution-Expansion mechanism where expansion of the
+-- children is performed before expansion of the parent does not work if the
+-- code generated for the children by the expander needs to be evaluated
+-- repeatdly (for instance in the above aggregate "new Thing (Function_Call)"
+-- needs to be called 100 times.)
+
+-- The reason why this mecanism does not work is that, the expanded code for
+-- the children is typically inserted above the parent and thus when the
+-- father gets expanded no re-evaluation takes place. For instance in the case
+-- of aggregates if "new Thing (Function_Call)" is expanded before of the
+-- aggregate the expanded code will be placed outside of the aggregate and
+-- when expanding the aggregate the loop from 1 to 100 will not surround the
+-- expanded code for "new Thing (Function_Call)".
+
+-- To remedy this situation we introduce a new flag which signals whether we
+-- want a full analysis (ie expansion is enabled) or a pre-analysis which
+-- performs Analysis and Resolution but no expansion.
+
+-- After the complete pre-analysis of an expression has been carried out we
+-- can transform the expression and then carry out the full three stage
+-- (Analyze-Resolve-Expand) cycle on the transformed expression top-down so
+-- that the expansion of inner expressions happens inside the newly generated
+-- node for the parent expression.
+
-- Note that the difference between processing of default expressions and
-- pre-analysis of other expressions is that we do carry out freezing in
-- the latter but not in the former (except for static scalar expressions).
--- The routine that performs pre-analysis is called Pre_Analyze_And_Resolve
--- and is in Sem_Res.
+-- The routine that performs preanalysis and corresponding resolution is
+-- called Preanalyze_And_Resolve and is in Sem_Res.
with Alloc;
with Einfo; use Einfo;
-- whether expansion is currently enabled). You should really regard this
-- as a read only flag.
- In_Default_Expression : Boolean := False;
- -- Switch to indicate that we are in a default expression, as described
+ In_Spec_Expression : Boolean := False;
+ -- Switch to indicate that we are in a spec-expression, as described
-- above. Note that this must be recursively saved on a Semantics call
-- since it is possible for the analysis of an expression to result in a
-- recursive call (e.g. to get the entity for System.Address as part of the
-- package Expander). Only the generic processing can modify the
-- status of this flag, any other client should regard it as read-only.
+ Inside_Freezing_Actions : Nat := 0;
+ -- Flag indicating whether we are within a call to Expand_N_Freeze_Actions.
+ -- Non-zero means we are inside (it is actually a level counter to deal
+ -- with nested calls). Used to avoid traversing the tree each time a
+ -- subprogram call is processed to know if we must not clear all constant
+ -- indications from entities in the current scope. Only the expansion of
+ -- freezing nodes can modify the status of this flag, any other client
+ -- should regard it as read-only.
+
Unloaded_Subunits : Boolean := False;
-- This flag is set True if we have subunits that are not loaded. This
-- occurs when the main unit is a subunit, and contains lower level
-- subunits that are not loaded. We use this flag to suppress warnings
-- about unused variables, since these warnings are unreliable in this
-- case. We could perhaps do a more accurate job and retain some of the
- -- warnings, but it is quite a tricky job. See test 4323-002.
- -- Should not reference TN's in the source comments ???
+ -- warnings, but it is quite a tricky job.
-----------------------------------
-- Handling of Check Suppression --
Save_Local_Suppress_Stack_Top : Suppress_Stack_Entry_Ptr;
-- Save contents of Local_Suppress_Stack on entry to restore on exit
+ Save_Check_Policy_List : Node_Id;
+ -- Save contents of Check_Policy_List on entry to restore on exit
+
Is_Transient : Boolean;
-- Marks Transient Scopes (See Exp_Ch7 body for details)
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