gcc/ada/sem_ch12.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             S E M _ C H 1 2                              --
   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 Inline; use Inline;
  27 with Types;  use Types;
  28
  29 package Sem_Ch12 is
  30    procedure Analyze_Generic_Package_Declaration        (N : Node_Id);
  31    procedure Analyze_Generic_Subprogram_Declaration     (N : Node_Id);
  32    procedure Analyze_Package_Instantiation              (N : Node_Id);
  33    procedure Analyze_Procedure_Instantiation            (N : Node_Id);
  34    procedure Analyze_Function_Instantiation             (N : Node_Id);
  35    procedure Analyze_Formal_Object_Declaration          (N : Node_Id);
  36    procedure Analyze_Formal_Type_Declaration            (N : Node_Id);
  37    procedure Analyze_Formal_Subprogram                  (N : Node_Id);
  38    procedure Analyze_Formal_Package                     (N : Node_Id);
  39
  40    procedure Start_Generic;
  41    --  Must be invoked before starting to process a generic spec or body
  42
  43    procedure End_Generic;
  44    --  Must be invoked just at the end of the end of the processing of a
  45    --  generic spec or body.
  46
  47    procedure Check_Generic_Child_Unit
  48      (Gen_Id           : Node_Id;
  49       Parent_Installed : in out Boolean);
  50    --  If the name of the generic unit in an instantiation or a renaming
  51    --  is a selected component, then the prefix may be an instance and the
  52    --  selector may  designate a child unit. Retrieve the parent generic
  53    --  and search for the child unit that must be declared within. Similarly,
  54    --  if this is the name of a generic child unit within an instantiation of
  55    --  its own parent, retrieve the parent generic.
  56
  57    function Copy_Generic_Node
  58      (N             : Node_Id;
  59       Parent_Id     : Node_Id;
  60       Instantiating : Boolean) return Node_Id;
  61    --  Copy the tree for a generic unit or its body. The unit is copied
  62    --  repeatedly: once to produce a copy on which semantic analysis of
  63    --  the generic is performed, and once for each instantiation. The tree
  64    --  being copied is not semantically analyzed, except that references to
  65    --  global entities are marked on terminal nodes.
  66
  67    function Get_Instance_Of (A : Entity_Id) return Entity_Id;
  68    --  Retrieve actual associated with given generic parameter.
  69    --  If A is uninstantiated or not a generic parameter, return A.
  70
  71    function Get_Package_Instantiation_Node (A : Entity_Id) return Node_Id;
  72    --  Given the entity of a unit that is an instantiation, retrieve the
  73    --  original instance node. This is used when loading the instantiations
  74    --  of the ancestors of a child generic that is being instantiated.
  75
  76    procedure Instantiate_Package_Body
  77      (Body_Info     : Pending_Body_Info;
  78       Inlined_Body  : Boolean := False;
  79       Body_Optional : Boolean := False);
  80    --  Called after semantic analysis, to complete the instantiation of
  81    --  package instances. The flag Inlined_Body is set if the body is
  82    --  being instantiated on the fly for inlined purposes.
  83    --
  84    --  The flag Body_Optional indicates that the call is for an instance
  85    --  that precedes the current instance in the same declarative part.
  86    --  This call is needed when instantiating a nested generic whose body
  87    --  is to be found in the body of an instance. Normally we instantiate
  88    --  package bodies only when they appear in the main unit, or when their
  89    --  contents are needed for a nested generic G. If unit U contains several
  90    --  instances I1, I2, etc. and I2 contains a nested generic, then when U
  91    --  appears in the context of some other unit P that contains an instance
  92    --  of G, we compile the body of I2, but not that of I1. However, when we
  93    --  compile U as the main unit, we compile both bodies. This will lead to
  94    --  lead to link-time errors if the compilation of I1 generates public
  95    --  symbols, because those in I2 will receive different names in both
  96    --  cases. This forces us to analyze the body of I1 even when U is not the
  97    --  main unit. We don't want this additional mechanism to generate an error
  98    --  when the body of the generic for I1 is not present, and this is the
  99    --  reason for the presence of the flag Body_Optional, which is exchanged
 100    --  between the current procedure and Load_Parent_Of_Generic.
 101
 102    procedure Instantiate_Subprogram_Body
 103      (Body_Info     : Pending_Body_Info;
 104       Body_Optional : Boolean := False);
 105    --  Called after semantic analysis, to complete the instantiation of
 106    --  function and procedure instances. The flag Body_Optional has the
 107    --  same purpose as described for Instantiate_Package_Body.
 108
 109    procedure Save_Global_References (N : Node_Id);
 110    --  Traverse the original generic unit, and capture all references to
 111    --  entities that are defined outside of the generic in the analyzed
 112    --  tree for the template. These references are copied into the original
 113    --  tree, so that they appear automatically in every instantiation.
 114    --  A critical invariant in this approach is that if an id in the generic
 115    --  resolves to a local entity, the corresponding id in the instance
 116    --  will resolve to the homologous entity in the instance, even though
 117    --  the enclosing context for resolution is different, as long as the
 118    --  global references have been captured as described here.
 119
 120    --  Because instantiations can be nested, the environment of the instance,
 121    --  involving the actuals and other data-structures, must be saved and
 122    --  restored in stack-like fashion. Front-end inlining also uses these
 123    --  structures for the management of private/full views.
 124
 125    procedure Set_Copied_Sloc_For_Inlined_Body (N : Node_Id; E : Entity_Id);
 126    --  This procedure is used when a subprogram body is inlined. This process
 127    --  shares the same circuitry as the creation of an instantiated copy of
 128    --  a generic template. The call to this procedure establishes a new source
 129    --  file entry representing the inlined body as an instantiation, marked as
 130    --  an inlined body (so that errout can distinguish cases for generating
 131    --  error messages, otherwise the treatment is identical). In this call
 132    --  N is the subprogram body and E is the defining identifier of the
 133    --  subprogram in question. The resulting Sloc adjustment factor is
 134    --  saved as part of the internal state of the Sem_Ch12 package for use
 135    --  in subsequent calls to copy nodes.
 136
 137    procedure Save_Env
 138      (Gen_Unit : Entity_Id;
 139       Act_Unit : Entity_Id);
 140    --   ??? comment needed
 141
 142    procedure Restore_Env;
 143    --   ??? comment needed
 144
 145    procedure Initialize;
 146    --  Initializes internal data structures
 147
 148    procedure Check_Private_View (N : Node_Id);
 149    --  Check whether the type of a generic entity has a different view between
 150    --  the point of generic analysis and the point of instantiation. If the
 151    --  view has changed, then at the point of instantiation we restore the
 152    --  correct view to perform semantic analysis of the instance, and reset
 153    --  the current view after instantiation. The processing is driven by the
 154    --  current private status of the type of the node, and Has_Private_View,
 155    --  a flag that is set at the point of generic compilation. If view and
 156    --  flag are inconsistent then the type is updated appropriately.
 157    --
 158    --  This subprogram is used in Check_Generic_Actuals and Copy_Generic_Node,
 159    --  and is exported here for the purpose of front-end inlining (see Exp_Ch6.
 160    --  Expand_Inlined_Call.Process_Formals).
 161
 162 end Sem_Ch12;