gcc/ada/exp_ch6.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              E X P _ C H 6                               --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2014, 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 --  Expand routines for chapter 6 constructs
  27
  28 with Types; use Types;
  29
  30 package Exp_Ch6 is
  31
  32    procedure Expand_N_Extended_Return_Statement (N : Node_Id);
  33    procedure Expand_N_Function_Call             (N : Node_Id);
  34    procedure Expand_N_Procedure_Call_Statement  (N : Node_Id);
  35    procedure Expand_N_Simple_Return_Statement   (N : Node_Id);
  36    procedure Expand_N_Subprogram_Body           (N : Node_Id);
  37    procedure Expand_N_Subprogram_Body_Stub      (N : Node_Id);
  38    procedure Expand_N_Subprogram_Declaration    (N : Node_Id);
  39
  40    procedure Expand_Call (N : Node_Id);
  41    --  This procedure contains common processing for Expand_N_Function_Call,
  42    --  Expand_N_Procedure_Statement, and Expand_N_Entry_Call.
  43
  44    procedure Expand_Subprogram_Contract
  45      (N       : Node_Id;
  46       Spec_Id : Entity_Id;
  47       Body_Id : Entity_Id);
  48    --  Expand the contracts of a subprogram body and its correspoding spec (if
  49    --  any). This routine processes all [refined] pre- and postconditions as
  50    --  well as Contract_Cases, invariants and predicates. N is the body of the
  51    --  subprogram. Spec_Id denotes the entity of its specification. Body_Id
  52    --  denotes the entity of the subprogram body. This routine is not a "pure"
  53    --  expansion mechanism as it is invoked during analysis and may perform
  54    --  actions for generic subprograms or set up contract assertions for ASIS.
  55
  56    procedure Freeze_Subprogram (N : Node_Id);
  57    --  generate the appropriate expansions related to Subprogram freeze
  58    --  nodes (e.g. the filling of the corresponding Dispatch Table for
  59    --  Primitive Operations)
  60
  61    --  The following type defines the various forms of allocation used for the
  62    --  results of build-in-place function calls.
  63
  64    type BIP_Allocation_Form is
  65      (Unspecified,
  66       Caller_Allocation,
  67       Secondary_Stack,
  68       Global_Heap,
  69       User_Storage_Pool);
  70
  71    type BIP_Formal_Kind is
  72    --  Ada 2005 (AI-318-02): This type defines the kinds of implicit extra
  73    --  formals created for build-in-place functions. The order of these
  74    --  enumeration literals matches the order in which the formals are
  75    --  declared. See Sem_Ch6.Create_Extra_Formals.
  76
  77      (BIP_Alloc_Form,
  78       --  Present if result subtype is unconstrained or tagged. Indicates
  79       --  whether the return object is allocated by the caller or callee, and
  80       --  if the callee, whether to use the secondary stack or the heap. See
  81       --  Create_Extra_Formals.
  82
  83       BIP_Storage_Pool,
  84       --  Present if result subtype is unconstrained or tagged. If
  85       --  BIP_Alloc_Form = User_Storage_Pool, this is a pointer to the pool
  86       --  (of type access to Root_Storage_Pool'Class). Otherwise null.
  87
  88       BIP_Finalization_Master,
  89       --  Present if result type needs finalization. Pointer to caller's
  90       --  finalization master.
  91
  92       BIP_Task_Master,
  93       --  Present if result type contains tasks. Master associated with
  94       --  calling context.
  95
  96       BIP_Activation_Chain,
  97       --  Present if result type contains tasks. Caller's activation chain
  98
  99       BIP_Object_Access);
 100       --  Present for all build-in-place functions. Address at which to place
 101       --  the return object, or null if BIP_Alloc_Form indicates allocated by
 102       --  callee.
 103       --
 104       --  ??? We might also need to be able to pass in a constrained flag.
 105
 106    function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String;
 107    --  Ada 2005 (AI-318-02): Returns a string to be used as the suffix of names
 108    --  for build-in-place formal parameters of the given kind.
 109
 110    function Build_In_Place_Formal
 111      (Func : Entity_Id;
 112       Kind : BIP_Formal_Kind) return Entity_Id;
 113    --  Ada 2005 (AI-318-02): Locates and returns the entity for the implicit
 114    --  build-in-place formal parameter of the given kind associated with the
 115    --  function Func, and returns its Entity_Id. It is a bug if not found; the
 116    --  caller should ensure this is called only when the extra formal exists.
 117
 118    function Is_Build_In_Place_Function (E : Entity_Id) return Boolean;
 119    --  Ada 2005 (AI-318-02): Returns True if E denotes a function, generic
 120    --  function, or access-to-function type whose result must be built in
 121    --  place; otherwise returns False. For Ada 2005, this is currently
 122    --  restricted to the set of functions whose result subtype is an inherently
 123    --  limited type. In Ada 95, this must be False for inherently limited
 124    --  result types (but currently returns False for all Ada 95 functions).
 125    --  Eventually we plan to support build-in-place for nonlimited types.
 126    --  Build-in-place is usually more efficient for large things, and less
 127    --  efficient for small things. However, we never use build-in-place if the
 128    --  convention is other than Ada, because that would disturb mixed-language
 129    --  programs. Note that for the non-inherently-limited cases, we must make
 130    --  the same decision for Ada 95 and 2005, so that mixed-dialect programs
 131    --  will work.
 132
 133    function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean;
 134    --  Ada 2005 (AI-318-02): Returns True if N denotes a call to a function
 135    --  that requires handling as a build-in-place call or is a qualified
 136    --  expression applied to such a call; otherwise returns False.
 137
 138    function Is_Null_Procedure (Subp : Entity_Id) return Boolean;
 139    --  Predicate to recognize stubbed procedures and null procedures, which
 140    --  can be inlined unconditionally in all cases.
 141
 142    procedure Make_Build_In_Place_Call_In_Allocator
 143      (Allocator     : Node_Id;
 144       Function_Call : Node_Id);
 145    --  Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
 146    --  occurs as the expression initializing an allocator, by passing access
 147    --  to the allocated object as an additional parameter of the function call.
 148    --  A new access object is declared that is initialized to the result of the
 149    --  allocator, passed to the function, and the allocator is rewritten to
 150    --  refer to that access object. Function_Call must denote either an
 151    --  N_Function_Call node for which Is_Build_In_Place_Call is True, or else
 152    --  an N_Qualified_Expression node applied to such a function call.
 153
 154    procedure Make_Build_In_Place_Call_In_Anonymous_Context
 155      (Function_Call : Node_Id);
 156    --  Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
 157    --  occurs in a context that does not provide a separate object. A temporary
 158    --  object is created to act as the return object and an access to the
 159    --  temporary is passed as an additional parameter of the call. This occurs
 160    --  in contexts such as subprogram call actuals and object renamings.
 161    --  Function_Call must denote either an N_Function_Call node for which
 162    --  Is_Build_In_Place_Call is True, or else an N_Qualified_Expression node
 163    --  applied to such a function call.
 164
 165    procedure Make_Build_In_Place_Call_In_Assignment
 166      (Assign        : Node_Id;
 167       Function_Call : Node_Id);
 168    --  Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
 169    --  occurs as the right-hand side of an assignment statement by passing
 170    --  access to the left-hand side as an additional parameter of the function
 171    --  call. Assign must denote a N_Assignment_Statement. Function_Call must
 172    --  denote either an N_Function_Call node for which Is_Build_In_Place_Call
 173    --  is True, or an N_Qualified_Expression node applied to such a function
 174    --  call.
 175
 176    procedure Make_Build_In_Place_Call_In_Object_Declaration
 177      (Object_Decl   : Node_Id;
 178       Function_Call : Node_Id);
 179    --  Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
 180    --  occurs as the expression initializing an object declaration by
 181    --  passing access to the declared object as an additional parameter of the
 182    --  function call. Function_Call must denote either an N_Function_Call node
 183    --  for which Is_Build_In_Place_Call is True, or an N_Qualified_Expression
 184    --  node applied to such a function call.
 185
 186    procedure Make_CPP_Constructor_Call_In_Allocator
 187      (Allocator     : Node_Id;
 188       Function_Call : Node_Id);
 189    --  Handle a call to a CPP constructor that occurs as the expression that
 190    --  initializes an allocator, by passing access to the allocated object as
 191    --  an additional parameter of the constructor call. A new access object is
 192    --  declared that is initialized to the result of the allocator, passed to
 193    --  the constructor, and the allocator is rewritten to refer to that access
 194    --  object. Function_Call must denote a call to a CPP_Constructor function.
 195
 196    function Needs_BIP_Alloc_Form (Func_Id : Entity_Id) return Boolean;
 197    --  Ada 2005 (AI-318-02): Return True if the function needs an implicit
 198    --  BIP_Alloc_Form parameter (see type BIP_Formal_Kind).
 199
 200    function Needs_BIP_Finalization_Master (Func_Id : Entity_Id) return Boolean;
 201    --  Ada 2005 (AI-318-02): Return True if the result subtype of function
 202    --  Func_Id needs finalization actions.
 203
 204    function Needs_Result_Accessibility_Level
 205      (Func_Id : Entity_Id) return Boolean;
 206    --  Ada 2012 (AI05-0234): Return True if the function needs an implicit
 207    --  parameter to identify the accessibility level of the function result
 208    --  "determined by the point of call".
 209
 210    procedure Add_Extra_Actual_To_Call
 211      (Subprogram_Call : Node_Id;
 212       Extra_Formal    : Entity_Id;
 213       Extra_Actual    : Node_Id);
 214    --  Adds Extra_Actual as a named parameter association for the formal
 215    --  Extra_Formal in Subprogram_Call.
 216
 217 end Exp_Ch6;