gcc/ada/sem_ch6.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              S E M _ C H 6                               --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2010, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
  19 -- http://www.gnu.org/licenses for a complete copy of the license.          --
  20 --                                                                          --
  21 -- GNAT was originally developed  by the GNAT team at  New York University. --
  22 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  23 --                                                                          --
  24 ------------------------------------------------------------------------------
  25
  26 with Types; use Types;
  27 package Sem_Ch6 is
  28
  29    type Conformance_Type is
  30      (Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant);
  31    pragma Ordered (Conformance_Type);
  32    --  Conformance type used in conformance checks between specs and bodies,
  33    --  and for overriding. The literals match the RM definitions of the
  34    --  corresponding terms. This is an ordered type, since each conformance
  35    --  type is stronger than the ones preceding it.
  36
  37    procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id);
  38    procedure Analyze_Extended_Return_Statement       (N : Node_Id);
  39    procedure Analyze_Function_Call                   (N : Node_Id);
  40    procedure Analyze_Operator_Symbol                 (N : Node_Id);
  41    procedure Analyze_Parameter_Association           (N : Node_Id);
  42    procedure Analyze_Parameterized_Expression        (N : Node_Id);
  43    procedure Analyze_Procedure_Call                  (N : Node_Id);
  44    procedure Analyze_Simple_Return_Statement         (N : Node_Id);
  45    procedure Analyze_Subprogram_Declaration          (N : Node_Id);
  46    procedure Analyze_Subprogram_Body                 (N : Node_Id);
  47
  48    function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id;
  49    --  Analyze subprogram specification in both subprogram declarations
  50    --  and body declarations. Returns the defining entity for the
  51    --  specification N.
  52
  53    procedure Cannot_Inline (Msg : String; N : Node_Id; Subp : Entity_Id);
  54    --  This procedure is called if the node N, an instance of a call to
  55    --  subprogram Subp, cannot be inlined. Msg is the message to be issued,
  56    --  and has a ? as the last character. If Subp has a pragma Always_Inlined,
  57    --  then an error message is issued (by removing the last character of Msg).
  58    --  If Subp is not Always_Inlined, then a warning is issued if the flag
  59    --  Ineffective_Inline_Warnings is set, and if not, the call has no effect.
  60
  61    procedure Check_Conventions (Typ : Entity_Id);
  62    --  Ada 2005 (AI-430): Check that the conventions of all inherited and
  63    --  overridden dispatching operations of type Typ are consistent with their
  64    --  respective counterparts.
  65
  66    procedure Check_Delayed_Subprogram (Designator : Entity_Id);
  67    --  Designator can be a E_Subprogram_Type, E_Procedure or E_Function. If a
  68    --  type in its profile depends on a private type without a full
  69    --  declaration, indicate that the subprogram or type is delayed.
  70
  71    procedure Check_Discriminant_Conformance
  72      (N        : Node_Id;
  73       Prev     : Entity_Id;
  74       Prev_Loc : Node_Id);
  75    --  Check that the discriminants of a full type N fully conform to the
  76    --  discriminants of the corresponding partial view Prev. Prev_Loc indicates
  77    --  the source location of the partial view, which may be different than
  78    --  Prev in the case of private types.
  79
  80    procedure Check_Fully_Conformant
  81      (New_Id  : Entity_Id;
  82       Old_Id  : Entity_Id;
  83       Err_Loc : Node_Id := Empty);
  84    --  Check that two callable entities (subprograms, entries, literals)
  85    --  are fully conformant, post error message if not (RM 6.3.1(17)) with
  86    --  the flag being placed on the Err_Loc node if it is specified, and
  87    --  on the appropriate component of the New_Id construct if not. Note:
  88    --  when checking spec/body conformance, New_Id must be the body entity
  89    --  and Old_Id is the spec entity (the code in the implementation relies
  90    --  on this ordering, and in any case, this makes sense, since if flags
  91    --  are to be placed on the construct, they clearly belong on the body.
  92
  93    procedure Check_Mode_Conformant
  94      (New_Id   : Entity_Id;
  95       Old_Id   : Entity_Id;
  96       Err_Loc  : Node_Id := Empty;
  97       Get_Inst : Boolean := False);
  98    --  Check that two callable entities (subprograms, entries, literals)
  99    --  are mode conformant, post error message if not (RM 6.3.1(15)) with
 100    --  the flag being placed on the Err_Loc node if it is specified, and
 101    --  on the appropriate component of the New_Id construct if not. The
 102    --  argument Get_Inst is set to True when this is a check against a
 103    --  formal access-to-subprogram type, indicating that mapping of types
 104    --  is needed.
 105
 106    procedure Check_Overriding_Indicator
 107      (Subp            : Entity_Id;
 108       Overridden_Subp : Entity_Id;
 109       Is_Primitive    : Boolean);
 110    --  Verify the consistency of an overriding_indicator given for subprogram
 111    --  declaration, body, renaming, or instantiation.  Overridden_Subp is set
 112    --  if the scope where we are introducing the subprogram contains a
 113    --  type-conformant subprogram that becomes hidden by the new subprogram.
 114    --  Is_Primitive indicates whether the subprogram is primitive.
 115
 116    procedure Check_Subtype_Conformant
 117      (New_Id                   : Entity_Id;
 118       Old_Id                   : Entity_Id;
 119       Err_Loc                  : Node_Id := Empty;
 120       Skip_Controlling_Formals : Boolean := False);
 121    --  Check that two callable entities (subprograms, entries, literals)
 122    --  are subtype conformant, post error message if not (RM 6.3.1(16)),
 123    --  the flag being placed on the Err_Loc node if it is specified, and
 124    --  on the appropriate component of the New_Id construct if not.
 125    --  Skip_Controlling_Formals is True when checking the conformance of
 126    --  a subprogram that implements an interface operation. In that case,
 127    --  only the non-controlling formals can (and must) be examined.
 128
 129    procedure Check_Type_Conformant
 130      (New_Id  : Entity_Id;
 131       Old_Id  : Entity_Id;
 132       Err_Loc : Node_Id := Empty);
 133    --  Check that two callable entities (subprograms, entries, literals)
 134    --  are type conformant, post error message if not (RM 6.3.1(14)) with
 135    --  the flag being placed on the Err_Loc node if it is specified, and
 136    --  on the appropriate component of the New_Id construct if not.
 137
 138    function Conforming_Types
 139      (T1       : Entity_Id;
 140       T2       : Entity_Id;
 141       Ctype    : Conformance_Type;
 142       Get_Inst : Boolean := False) return Boolean;
 143    --  Check that the types of two formal parameters are conforming. In most
 144    --  cases this is just a name comparison, but within an instance it involves
 145    --  generic actual types, and in the presence of anonymous access types it
 146    --  must examine the designated types.
 147
 148    procedure Create_Extra_Formals (E : Entity_Id);
 149    --  For each parameter of a subprogram or entry that requires an additional
 150    --  formal (such as for access parameters and indefinite discriminated
 151    --  parameters), creates the appropriate formal and attach it to its
 152    --  associated parameter. Each extra formal will also be appended to
 153    --  the end of Subp's parameter list (with each subsequent extra formal
 154    --  being attached to the preceding extra formal).
 155
 156    function Find_Corresponding_Spec
 157      (N          : Node_Id;
 158       Post_Error : Boolean := True) return Entity_Id;
 159    --  Use the subprogram specification in the body to retrieve the previous
 160    --  subprogram declaration, if any.
 161
 162    function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean;
 163    --  Determine whether two callable entities (subprograms, entries,
 164    --  literals) are fully conformant (RM 6.3.1(17))
 165
 166    function Fully_Conformant_Expressions
 167      (Given_E1 : Node_Id;
 168       Given_E2 : Node_Id) return Boolean;
 169    --  Determines if two (non-empty) expressions are fully conformant
 170    --  as defined by (RM 6.3.1(18-21))
 171
 172    function Fully_Conformant_Discrete_Subtypes
 173       (Given_S1 : Node_Id;
 174        Given_S2 : Node_Id) return Boolean;
 175    --  Determines if two subtype definitions are fully conformant. Used
 176    --  for entry family conformance checks (RM 6.3.1 (24)).
 177
 178    procedure Install_Formals (Id : Entity_Id);
 179    --  On entry to a subprogram body, make the formals visible. Note that
 180    --  simply placing the subprogram on the scope stack is not sufficient:
 181    --  the formals must become the current entities for their names. This
 182    --  procedure is also used to get visibility to the formals when analyzing
 183    --  preconditions and postconditions appearing in the spec.
 184
 185    function Is_Interface_Conformant
 186      (Tagged_Type : Entity_Id;
 187       Iface_Prim  : Entity_Id;
 188       Prim        : Entity_Id) return Boolean;
 189    --  Returns true if both primitives have a matching name, they are type
 190    --  conformant, and Prim is defined in the scope of Tagged_Type. Special
 191    --  management is done for functions returning interfaces.
 192
 193    procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id);
 194    --  E is the entity for a subprogram or generic subprogram spec. This call
 195    --  lists all inherited Pre/Post aspects if List_Inherited_Pre_Post is True.
 196
 197    function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean;
 198    --  Determine whether two callable entities (subprograms, entries,
 199    --  literals) are mode conformant (RM 6.3.1(15))
 200
 201    procedure New_Overloaded_Entity
 202      (S            : Entity_Id;
 203       Derived_Type : Entity_Id := Empty);
 204    --  Process new overloaded entity. Overloaded entities are created by
 205    --  enumeration type declarations, subprogram specifications, entry
 206    --  declarations, and (implicitly) by type derivations. Derived_Type non-
 207    --  Empty indicates that this is subprogram derived for that type.
 208
 209    procedure Process_Formals (T : List_Id; Related_Nod : Node_Id);
 210    --  Enter the formals in the scope of the subprogram or entry, and
 211    --  analyze default expressions if any. The implicit types created for
 212    --  access parameter are attached to the Related_Nod which comes from the
 213    --  context.
 214
 215    procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id);
 216    --  If there is a separate spec for a subprogram or generic subprogram, the
 217    --  formals of the body are treated as references to the corresponding
 218    --  formals of the spec. This reference does not count as an actual use of
 219    --  the formal, in order to diagnose formals that are unused in the body.
 220    --  This procedure is also used in renaming_as_body declarations, where
 221    --  the formals of the specification must be treated as body formals that
 222    --  correspond to the previous subprogram declaration, and not as new
 223    --  entities with their defining entry in the cross-reference information.
 224
 225    procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id);
 226    --  If the formals of a subprogram are unconstrained, build a subtype
 227    --  declaration that uses the bounds or discriminants of the actual to
 228    --  construct an actual subtype for them. This is an optimization that
 229    --  is done only in some cases where the actual subtype cannot change
 230    --  during execution of the subprogram. By setting the actual subtype
 231    --  once, we avoid recomputing it unnecessarily.
 232
 233    procedure Set_Formal_Mode (Formal_Id : Entity_Id);
 234    --  Set proper Ekind to reflect formal mode (in, out, in out)
 235
 236    function Subtype_Conformant
 237      (New_Id                   : Entity_Id;
 238       Old_Id                   : Entity_Id;
 239       Skip_Controlling_Formals : Boolean := False) return Boolean;
 240    --  Determine whether two callable entities (subprograms, entries, literals)
 241    --  are subtype conformant (RM6.3.1(16)).  Skip_Controlling_Formals is True
 242    --  when checking the conformance of a subprogram that implements an
 243    --  interface operation. In that case, only the non-controlling formals
 244    --  can (and must) be examined.
 245
 246    function Type_Conformant
 247      (New_Id                   : Entity_Id;
 248       Old_Id                   : Entity_Id;
 249       Skip_Controlling_Formals : Boolean := False) return Boolean;
 250    --  Determine whether two callable entities (subprograms, entries, literals)
 251    --  are type conformant (RM6.3.1(14)). Skip_Controlling_Formals is True when
 252    --  checking the conformance of a subprogram that implements an interface
 253    --  operation. In that case, only the non-controlling formals can (and must)
 254    --  be examined.
 255
 256    procedure Valid_Operator_Definition (Designator : Entity_Id);
 257    --  Verify that an operator definition has the proper number of formals
 258
 259 end Sem_Ch6;