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) 1992-2008, 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    --  Conformance type used in conformance checks between specs and bodies,
  32    --  and for overriding. The literals match the RM definitions of the
  33    --  corresponding terms.
  34
  35    procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id);
  36    procedure Analyze_Extended_Return_Statement       (N : Node_Id);
  37    procedure Analyze_Function_Call                   (N : Node_Id);
  38    procedure Analyze_Operator_Symbol                 (N : Node_Id);
  39    procedure Analyze_Parameter_Association           (N : Node_Id);
  40    procedure Analyze_Procedure_Call                  (N : Node_Id);
  41    procedure Analyze_Simple_Return_Statement         (N : Node_Id);
  42    procedure Analyze_Subprogram_Declaration          (N : Node_Id);
  43    procedure Analyze_Subprogram_Body                 (N : Node_Id);
  44
  45    function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id;
  46    --  Analyze subprogram specification in both subprogram declarations
  47    --  and body declarations. Returns the defining entity for the
  48    --  specification N.
  49
  50    procedure Cannot_Inline (Msg : String; N : Node_Id; Subp : Entity_Id);
  51    --  This procedure is called if the node N, an instance of a call to
  52    --  subprogram Subp, cannot be inlined. Msg is the message to be issued,
  53    --  and has a ? as the last character. If Subp has a pragma Always_Inlined,
  54    --  then an error message is issued (by removing the last character of Msg).
  55    --  If Subp is not Always_Inlined, then a warning is issued if the flag
  56    --  Ineffective_Inline_Warnings is set, and if not, the call has no effect.
  57
  58    procedure Check_Conventions (Typ : Entity_Id);
  59    --  Ada 2005 (AI-430): Check that the conventions of all inherited and
  60    --  overridden dispatching operations of type Typ are consistent with their
  61    --  respective counterparts.
  62
  63    procedure Check_Delayed_Subprogram (Designator : Entity_Id);
  64    --  Designator can be a E_Subprogram_Type, E_Procedure or E_Function. If a
  65    --  type in its profile depends on a private type without a full
  66    --  declaration, indicate that the subprogram or type is delayed.
  67
  68    procedure Check_Discriminant_Conformance
  69      (N        : Node_Id;
  70       Prev     : Entity_Id;
  71       Prev_Loc : Node_Id);
  72    --  Check that the discriminants of a full type N fully conform to the
  73    --  discriminants of the corresponding partial view Prev. Prev_Loc indicates
  74    --  the source location of the partial view, which may be different than
  75    --  Prev in the case of private types.
  76
  77    procedure Check_Fully_Conformant
  78      (New_Id  : Entity_Id;
  79       Old_Id  : Entity_Id;
  80       Err_Loc : Node_Id := Empty);
  81    --  Check that two callable entities (subprograms, entries, literals)
  82    --  are fully conformant, post error message if not (RM 6.3.1(17)) with
  83    --  the flag being placed on the Err_Loc node if it is specified, and
  84    --  on the appropriate component of the New_Id construct if not. Note:
  85    --  when checking spec/body conformance, New_Id must be the body entity
  86    --  and Old_Id is the spec entity (the code in the implementation relies
  87    --  on this ordering, and in any case, this makes sense, since if flags
  88    --  are to be placed on the construct, they clearly belong on the body.
  89
  90    procedure Check_Mode_Conformant
  91      (New_Id   : Entity_Id;
  92       Old_Id   : Entity_Id;
  93       Err_Loc  : Node_Id := Empty;
  94       Get_Inst : Boolean := False);
  95    --  Check that two callable entities (subprograms, entries, literals)
  96    --  are mode conformant, post error message if not (RM 6.3.1(15)) with
  97    --  the flag being placed on the Err_Loc node if it is specified, and
  98    --  on the appropriate component of the New_Id construct if not. The
  99    --  argument Get_Inst is set to True when this is a check against a
 100    --  formal access-to-subprogram type, indicating that mapping of types
 101    --  is needed.
 102
 103    procedure Check_Overriding_Indicator
 104      (Subp            : Entity_Id;
 105       Overridden_Subp : Entity_Id;
 106       Is_Primitive    : Boolean);
 107    --  Verify the consistency of an overriding_indicator given for subprogram
 108    --  declaration, body, renaming, or instantiation.  Overridden_Subp is set
 109    --  if the scope where we are introducing the subprogram contains a
 110    --  type-conformant subprogram that becomes hidden by the new subprogram.
 111    --  Is_Primitive indicates whether the subprogram is primitive.
 112
 113    procedure Check_Subtype_Conformant
 114      (New_Id                   : Entity_Id;
 115       Old_Id                   : Entity_Id;
 116       Err_Loc                  : Node_Id := Empty;
 117       Skip_Controlling_Formals : Boolean := False);
 118    --  Check that two callable entities (subprograms, entries, literals)
 119    --  are subtype conformant, post error message if not (RM 6.3.1(16)),
 120    --  the flag being placed on the Err_Loc node if it is specified, and
 121    --  on the appropriate component of the New_Id construct if not.
 122    --  Skip_Controlling_Formals is True when checking the conformance of
 123    --  a subprogram that implements an interface operation. In that case,
 124    --  only the non-controlling formals can (and must) be examined.
 125
 126    procedure Check_Type_Conformant
 127      (New_Id  : Entity_Id;
 128       Old_Id  : Entity_Id;
 129       Err_Loc : Node_Id := Empty);
 130    --  Check that two callable entities (subprograms, entries, literals)
 131    --  are type conformant, post error message if not (RM 6.3.1(14)) with
 132    --  the flag being placed on the Err_Loc node if it is specified, and
 133    --  on the appropriate component of the New_Id construct if not.
 134
 135    function Conforming_Types
 136      (T1       : Entity_Id;
 137       T2       : Entity_Id;
 138       Ctype    : Conformance_Type;
 139       Get_Inst : Boolean := False) return Boolean;
 140    --  Check that the types of two formal parameters are conforming. In most
 141    --  cases this is just a name comparison, but within an instance it involves
 142    --  generic actual types, and in the presence of anonymous access types it
 143    --  must examine the designated types.
 144
 145    procedure Create_Extra_Formals (E : Entity_Id);
 146    --  For each parameter of a subprogram or entry that requires an additional
 147    --  formal (such as for access parameters and indefinite discriminated
 148    --  parameters), creates the appropriate formal and attach it to its
 149    --  associated parameter. Each extra formal will also be appended to
 150    --  the end of Subp's parameter list (with each subsequent extra formal
 151    --  being attached to the preceding extra formal).
 152
 153    function Find_Corresponding_Spec
 154      (N          : Node_Id;
 155       Post_Error : Boolean := True) return Entity_Id;
 156    --  Use the subprogram specification in the body to retrieve the previous
 157    --  subprogram declaration, if any.
 158
 159    function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean;
 160    --  Determine whether two callable entities (subprograms, entries,
 161    --  literals) are fully conformant (RM 6.3.1(17))
 162
 163    function Fully_Conformant_Expressions
 164      (Given_E1 : Node_Id;
 165       Given_E2 : Node_Id) return Boolean;
 166    --  Determines if two (non-empty) expressions are fully conformant
 167    --  as defined by (RM 6.3.1(18-21))
 168
 169    function Fully_Conformant_Discrete_Subtypes
 170       (Given_S1 : Node_Id;
 171        Given_S2 : Node_Id) return Boolean;
 172    --  Determines if two subtype definitions are fully conformant. Used
 173    --  for entry family conformance checks (RM 6.3.1 (24)).
 174
 175    procedure Install_Formals (Id : Entity_Id);
 176    --  On entry to a subprogram body, make the formals visible. Note that
 177    --  simply placing the subprogram on the scope stack is not sufficient:
 178    --  the formals must become the current entities for their names. This
 179    --  procedure is also used to get visibility to the formals when analyzing
 180    --  preconditions and postconditions appearing in the spec.
 181
 182    function Is_Interface_Conformant
 183      (Tagged_Type : Entity_Id;
 184       Iface_Prim  : Entity_Id;
 185       Prim        : Entity_Id) return Boolean;
 186    --  Returns true if both primitives have a matching name and they are also
 187    --  type conformant. Special management is done for functions returning
 188    --  interfaces.
 189
 190    function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean;
 191    --  Determine whether two callable entities (subprograms, entries,
 192    --  literals) are mode conformant (RM 6.3.1(15))
 193
 194    procedure New_Overloaded_Entity
 195      (S            : Entity_Id;
 196       Derived_Type : Entity_Id := Empty);
 197    --  Process new overloaded entity. Overloaded entities are created by
 198    --  enumeration type declarations, subprogram specifications, entry
 199    --  declarations, and (implicitly) by type derivations. Derived_Type non-
 200    --  Empty indicates that this is subprogram derived for that type.
 201
 202    procedure Process_Formals (T : List_Id; Related_Nod : Node_Id);
 203    --  Enter the formals in the scope of the subprogram or entry, and
 204    --  analyze default expressions if any. The implicit types created for
 205    --  access parameter are attached to the Related_Nod which comes from the
 206    --  context.
 207
 208    procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id);
 209    --  If there is a separate spec for a subprogram or generic subprogram, the
 210    --  formals of the body are treated as references to the corresponding
 211    --  formals of the spec. This reference does not count as an actual use of
 212    --  the formal, in order to diagnose formals that are unused in the body.
 213    --  This procedure is also used in renaming_as_body declarations, where
 214    --  the formals of the specification must be treated as body formals that
 215    --  correspond to the previous subprogram declaration, and not as new
 216    --  entities with their defining entry in the cross-reference information.
 217
 218    procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id);
 219    --  If the formals of a subprogram are unconstrained, build a subtype
 220    --  declaration that uses the bounds or discriminants of the actual to
 221    --  construct an actual subtype for them. This is an optimization that
 222    --  is done only in some cases where the actual subtype cannot change
 223    --  during execution of the subprogram. By setting the actual subtype
 224    --  once, we avoid recomputing it unnecessarily.
 225
 226    procedure Set_Formal_Mode (Formal_Id : Entity_Id);
 227    --  Set proper Ekind to reflect formal mode (in, out, in out)
 228
 229    function Subtype_Conformant
 230      (New_Id                   : Entity_Id;
 231       Old_Id                   : Entity_Id;
 232       Skip_Controlling_Formals : Boolean := False) return Boolean;
 233    --  Determine whether two callable entities (subprograms, entries, literals)
 234    --  are subtype conformant (RM6.3.1(16)).  Skip_Controlling_Formals is True
 235    --  when checking the conformance of a subprogram that implements an
 236    --  interface operation. In that case, only the non-controlling formals
 237    --  can (and must) be examined.
 238
 239    function Type_Conformant
 240      (New_Id                   : Entity_Id;
 241       Old_Id                   : Entity_Id;
 242       Skip_Controlling_Formals : Boolean := False) return Boolean;
 243    --  Determine whether two callable entities (subprograms, entries, literals)
 244    --  are type conformant (RM6.3.1(14)). Skip_Controlling_Formals is True when
 245    --  checking the conformance of a subprogram that implements an interface
 246    --  operation. In that case, only the non-controlling formals can (and must)
 247    --  be examined.
 248
 249    procedure Valid_Operator_Definition (Designator : Entity_Id);
 250    --  Verify that an operator definition has the proper number of formals
 251
 252 end Sem_Ch6;