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) 1992-2015, 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 (N : Node_Id);
  45    --  Expand the contracts of a subprogram body and its correspoding spec (if
  46    --  any). This routine processes all [refined] pre- and postconditions as
  47    --  well as Contract_Cases, invariants and predicates. N denotes the body of
  48    --  the subprogram.
  49
  50    procedure Freeze_Subprogram (N : Node_Id);
  51    --  generate the appropriate expansions related to Subprogram freeze
  52    --  nodes (e.g. the filling of the corresponding Dispatch Table for
  53    --  Primitive Operations)
  54
  55    --  The following type defines the various forms of allocation used for the
  56    --  results of build-in-place function calls.
  57
  58    type BIP_Allocation_Form is
  59      (Unspecified,
  60       Caller_Allocation,
  61       Secondary_Stack,
  62       Global_Heap,
  63       User_Storage_Pool);
  64
  65    type BIP_Formal_Kind is
  66    --  Ada 2005 (AI-318-02): This type defines the kinds of implicit extra
  67    --  formals created for build-in-place functions. The order of these
  68    --  enumeration literals matches the order in which the formals are
  69    --  declared. See Sem_Ch6.Create_Extra_Formals.
  70
  71      (BIP_Alloc_Form,
  72       --  Present if result subtype is unconstrained or tagged. Indicates
  73       --  whether the return object is allocated by the caller or callee, and
  74       --  if the callee, whether to use the secondary stack or the heap. See
  75       --  Create_Extra_Formals.
  76
  77       BIP_Storage_Pool,
  78       --  Present if result subtype is unconstrained or tagged. If
  79       --  BIP_Alloc_Form = User_Storage_Pool, this is a pointer to the pool
  80       --  (of type access to Root_Storage_Pool'Class). Otherwise null.
  81
  82       BIP_Finalization_Master,
  83       --  Present if result type needs finalization. Pointer to caller's
  84       --  finalization master.
  85
  86       BIP_Task_Master,
  87       --  Present if result type contains tasks. Master associated with
  88       --  calling context.
  89
  90       BIP_Activation_Chain,
  91       --  Present if result type contains tasks. Caller's activation chain
  92
  93       BIP_Object_Access);
  94       --  Present for all build-in-place functions. Address at which to place
  95       --  the return object, or null if BIP_Alloc_Form indicates allocated by
  96       --  callee.
  97       --
  98       --  ??? We might also need to be able to pass in a constrained flag.
  99
 100    procedure Add_Extra_Actual_To_Call
 101      (Subprogram_Call : Node_Id;
 102       Extra_Formal    : Entity_Id;
 103       Extra_Actual    : Node_Id);
 104    --  Adds Extra_Actual as a named parameter association for the formal
 105    --  Extra_Formal in Subprogram_Call.
 106
 107    function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String;
 108    --  Ada 2005 (AI-318-02): Returns a string to be used as the suffix of names
 109    --  for build-in-place formal parameters of the given kind.
 110
 111    function Build_In_Place_Formal
 112      (Func : Entity_Id;
 113       Kind : BIP_Formal_Kind) return Entity_Id;
 114    --  Ada 2005 (AI-318-02): Locates and returns the entity for the implicit
 115    --  build-in-place formal parameter of the given kind associated with the
 116    --  function Func, and returns its Entity_Id. It is a bug if not found; the
 117    --  caller should ensure this is called only when the extra formal exists.
 118
 119    procedure Initialize;
 120    --  Initialize internal tables
 121
 122    function Is_Build_In_Place_Function (E : Entity_Id) return Boolean;
 123    --  Ada 2005 (AI-318-02): Returns True if E denotes a function, generic
 124    --  function, or access-to-function type whose result must be built in
 125    --  place; otherwise returns False. For Ada 2005, this is currently
 126    --  restricted to the set of functions whose result subtype is an inherently
 127    --  limited type. In Ada 95, this must be False for inherently limited
 128    --  result types (but currently returns False for all Ada 95 functions).
 129    --  Eventually we plan to support build-in-place for nonlimited types.
 130    --  Build-in-place is usually more efficient for large things, and less
 131    --  efficient for small things. However, we never use build-in-place if the
 132    --  convention is other than Ada, because that would disturb mixed-language
 133    --  programs. Note that for the non-inherently-limited cases, we must make
 134    --  the same decision for Ada 95 and 2005, so that mixed-dialect programs
 135    --  will work.
 136
 137    function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean;
 138    --  Ada 2005 (AI-318-02): Returns True if N denotes a call to a function
 139    --  that requires handling as a build-in-place call or is a qualified
 140    --  expression applied to such a call; otherwise returns False.
 141
 142    function Is_Null_Procedure (Subp : Entity_Id) return Boolean;
 143    --  Predicate to recognize stubbed procedures and null procedures, which
 144    --  can be inlined unconditionally in all cases.
 145
 146    procedure Make_Build_In_Place_Call_In_Allocator
 147      (Allocator     : Node_Id;
 148       Function_Call : Node_Id);
 149    --  Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
 150    --  occurs as the expression initializing an allocator, by passing access
 151    --  to the allocated object as an additional parameter of the function call.
 152    --  A new access object is declared that is initialized to the result of the
 153    --  allocator, passed to the function, and the allocator is rewritten to
 154    --  refer to that access object. Function_Call must denote either an
 155    --  N_Function_Call node for which Is_Build_In_Place_Call is True, or else
 156    --  an N_Qualified_Expression node applied to such a function call.
 157
 158    procedure Make_Build_In_Place_Call_In_Anonymous_Context
 159      (Function_Call : Node_Id);
 160    --  Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
 161    --  occurs in a context that does not provide a separate object. A temporary
 162    --  object is created to act as the return object and an access to the
 163    --  temporary is passed as an additional parameter of the call. This occurs
 164    --  in contexts such as subprogram call actuals and object renamings.
 165    --  Function_Call must denote either an N_Function_Call node for which
 166    --  Is_Build_In_Place_Call is True, or else an N_Qualified_Expression node
 167    --  applied to such a function call.
 168
 169    procedure Make_Build_In_Place_Call_In_Assignment
 170      (Assign        : Node_Id;
 171       Function_Call : Node_Id);
 172    --  Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
 173    --  occurs as the right-hand side of an assignment statement by passing
 174    --  access to the left-hand side as an additional parameter of the function
 175    --  call. Assign must denote a N_Assignment_Statement. Function_Call must
 176    --  denote either an N_Function_Call node for which Is_Build_In_Place_Call
 177    --  is True, or an N_Qualified_Expression node applied to such a function
 178    --  call.
 179
 180    procedure Make_Build_In_Place_Call_In_Object_Declaration
 181      (Object_Decl   : Node_Id;
 182       Function_Call : Node_Id);
 183    --  Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
 184    --  occurs as the expression initializing an object declaration by
 185    --  passing access to the declared object as an additional parameter of the
 186    --  function call. Function_Call must denote either an N_Function_Call node
 187    --  for which Is_Build_In_Place_Call is True, or an N_Qualified_Expression
 188    --  node applied to such a function call.
 189
 190    procedure Make_CPP_Constructor_Call_In_Allocator
 191      (Allocator     : Node_Id;
 192       Function_Call : Node_Id);
 193    --  Handle a call to a CPP constructor that occurs as the expression that
 194    --  initializes an allocator, by passing access to the allocated object as
 195    --  an additional parameter of the constructor call. A new access object is
 196    --  declared that is initialized to the result of the allocator, passed to
 197    --  the constructor, and the allocator is rewritten to refer to that access
 198    --  object. Function_Call must denote a call to a CPP_Constructor function.
 199
 200    function Needs_BIP_Alloc_Form (Func_Id : Entity_Id) return Boolean;
 201    --  Ada 2005 (AI-318-02): Return True if the function needs an implicit
 202    --  BIP_Alloc_Form parameter (see type BIP_Formal_Kind).
 203
 204    function Needs_BIP_Finalization_Master (Func_Id : Entity_Id) return Boolean;
 205    --  Ada 2005 (AI-318-02): Return True if the result subtype of function
 206    --  Func_Id needs finalization actions.
 207
 208    function Needs_Result_Accessibility_Level
 209      (Func_Id : Entity_Id) return Boolean;
 210    --  Ada 2012 (AI05-0234): Return True if the function needs an implicit
 211    --  parameter to identify the accessibility level of the function result
 212    --  "determined by the point of call".
 213
 214    procedure Unnest_Subprograms;
 215    --  Called to unnest subprograms. If we are in unnest subprogram mode, and
 216    --  subprograms have been gathered in the Unest_Bodies table, this is the
 217    --  call that causes them to be processed for unnesting.
 218
 219 end Exp_Ch6;