gcc/ada/ghost.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                                G H O S T                                 --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2014-2017, 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 --  This package contains routines that deal with the static and runtime
  27 --  semantics of Ghost entities.
  28
  29 with Opt;   use Opt;
  30 with Types; use Types;
  31
  32 package Ghost is
  33
  34    procedure Add_Ignored_Ghost_Unit (Unit : Node_Id);
  35    --  Add a single ignored Ghost compilation unit to the internal table for
  36    --  post processing.
  37
  38    procedure Check_Ghost_Completion
  39      (Prev_Id  : Entity_Id;
  40       Compl_Id : Entity_Id);
  41    --  Verify that the Ghost policy of initial entity Prev_Id is compatible
  42    --  with the Ghost policy of completing entity Compl_Id. Emit an error if
  43    --  this is not the case.
  44
  45    procedure Check_Ghost_Context
  46      (Ghost_Id  : Entity_Id;
  47       Ghost_Ref : Node_Id);
  48    --  Determine whether node Ghost_Ref appears within a Ghost-friendly context
  49    --  where Ghost entity Ghost_Id can safely reside.
  50
  51    procedure Check_Ghost_Overriding
  52      (Subp            : Entity_Id;
  53       Overridden_Subp : Entity_Id);
  54    --  Verify that the Ghost policy of parent subprogram Overridden_Subp is
  55    --  compatible with the Ghost policy of overriding subprogram Subp. Emit
  56    --  an error if this is not the case.
  57
  58    procedure Check_Ghost_Primitive (Prim : Entity_Id; Typ : Entity_Id);
  59    --  Verify that the Ghost policy of primitive operation Prim is the same as
  60    --  the Ghost policy of tagged type Typ. Emit an error if this is not the
  61    --  case.
  62
  63    procedure Check_Ghost_Refinement
  64      (State      : Node_Id;
  65       State_Id   : Entity_Id;
  66       Constit    : Node_Id;
  67       Constit_Id : Entity_Id);
  68    --  Verify that the Ghost policy of constituent Constit_Id is compatible
  69    --  with the Ghost policy of abstract state State_I.
  70
  71    function Implements_Ghost_Interface (Typ : Entity_Id) return Boolean;
  72    --  Determine whether type Typ implements at least one Ghost interface
  73
  74    procedure Initialize;
  75    --  Initialize internal tables
  76
  77    procedure Install_Ghost_Mode (Mode : Ghost_Mode_Type);
  78    --  Set the value of global variable Ghost_Mode depending on the Ghost
  79    --  policy denoted by Mode.
  80
  81    function Is_Ghost_Assignment (N : Node_Id) return Boolean;
  82    --  Determine whether arbitrary node N denotes an assignment statement whose
  83    --  target is a Ghost entity.
  84
  85    function Is_Ghost_Declaration (N : Node_Id) return Boolean;
  86    --  Determine whether arbitrary node N denotes a declaration which defines
  87    --  a Ghost entity.
  88
  89    function Is_Ghost_Pragma (N : Node_Id) return Boolean;
  90    --  Determine whether arbitrary node N denotes a pragma which encloses a
  91    --  Ghost entity or is associated with a Ghost entity.
  92
  93    function Is_Ghost_Procedure_Call (N : Node_Id) return Boolean;
  94    --  Determine whether arbitrary node N denotes a procedure call invoking a
  95    --  Ghost procedure.
  96
  97    function Is_Ignored_Ghost_Unit (N : Node_Id) return Boolean;
  98    --  Determine whether compilation unit N is subject to pragma Ghost with
  99    --  policy Ignore.
 100
 101    procedure Lock;
 102    --  Lock internal tables before calling backend
 103
 104    procedure Mark_And_Set_Ghost_Assignment (N : Node_Id);
 105    --  Mark assignment statement N as Ghost when:
 106    --
 107    --    * The left hand side denotes a Ghost entity
 108    --
 109    --  Install the Ghost mode of the assignment statement. This routine starts
 110    --  a Ghost region and must be used in conjunction with Restore_Ghost_Mode.
 111
 112    procedure Mark_And_Set_Ghost_Body
 113      (N       : Node_Id;
 114       Spec_Id : Entity_Id);
 115    --  Mark package or subprogram body N as Ghost when:
 116    --
 117    --    * The body is subject to pragma Ghost
 118    --
 119    --    * The body completes a previous declaration whose spec denoted by
 120    --      Spec_Id is a Ghost entity.
 121    --
 122    --    * The body appears within a Ghost region
 123    --
 124    --  Install the Ghost mode of the body. This routine starts a Ghost region
 125    --  and must be used in conjunction with Restore_Ghost_Mode.
 126
 127    procedure Mark_And_Set_Ghost_Completion
 128      (N       : Node_Id;
 129       Prev_Id : Entity_Id);
 130    --  Mark completion N of a deferred constant or private type [extension]
 131    --  Ghost when:
 132    --
 133    --    * The entity of the previous declaration denoted by Prev_Id is Ghost
 134    --
 135    --    * The completion appears within a Ghost region
 136    --
 137    --  Install the Ghost mode of the completion. This routine starts a Ghost
 138    --  region and must be used in conjunction with Restore_Ghost_Mode.
 139
 140    procedure Mark_And_Set_Ghost_Declaration (N : Node_Id);
 141    --  Mark declaration N as Ghost when:
 142    --
 143    --    * The declaration is subject to pragma Ghost
 144    --
 145    --    * The declaration denotes a child package or subprogram and the parent
 146    --      is a Ghost unit.
 147    --
 148    --    * The declaration appears within a Ghost region
 149    --
 150    --  Install the Ghost mode of the declaration. This routine starts a Ghost
 151    --  region and must be used in conjunction with Restore_Ghost_Mode.
 152
 153    procedure Mark_And_Set_Ghost_Instantiation
 154      (N      : Node_Id;
 155       Gen_Id : Entity_Id);
 156    --  Mark instantiation N as Ghost when:
 157    --
 158    --    * The instantiation is subject to pragma Ghost
 159    --
 160    --    * The generic template denoted by Gen_Id is Ghost
 161    --
 162    --    * The instantiation appears within a Ghost region
 163    --
 164    --  Install the Ghost mode of the instantiation. This routine starts a Ghost
 165    --  region and must be used in conjunction with Restore_Ghost_Mode.
 166
 167    procedure Mark_And_Set_Ghost_Procedure_Call (N : Node_Id);
 168    --  Mark procedure call N as Ghost when:
 169    --
 170    --    * The procedure being invoked is a Ghost entity
 171    --
 172    --  Install the Ghost mode of the procedure call. This routine starts a
 173    --  Ghost region and must be used in conjunction with Restore_Ghost_Mode.
 174
 175    procedure Mark_Ghost_Clause (N : Node_Id);
 176    --  Mark use package, use type, or with clause N as Ghost when:
 177    --
 178    --    * The clause mentions a Ghost entity
 179
 180    procedure Mark_Ghost_Pragma
 181      (N  : Node_Id;
 182       Id : Entity_Id);
 183    --  Mark pragma N as Ghost when:
 184    --
 185    --    * The pragma encloses Ghost entity Id
 186    --
 187    --    * The pragma is associated with Ghost entity Id
 188
 189    procedure Mark_Ghost_Renaming
 190      (N  : Node_Id;
 191       Id : Entity_Id);
 192    --  Mark renaming declaration N as Ghost when:
 193    --
 194    --    * Renamed entity Id denotes a Ghost entity
 195
 196    procedure Remove_Ignored_Ghost_Code;
 197    --  Remove all code marked as ignored Ghost from the trees of all qualifying
 198    --  units (SPARK RM 6.9(4)).
 199    --
 200    --  WARNING: this is a separate front end pass, care should be taken to keep
 201    --  it optimized.
 202
 203    procedure Restore_Ghost_Mode (Mode : Ghost_Mode_Type);
 204    --  Terminate a Ghost region by restoring the Ghost mode prior to the
 205    --  region denoted by Mode. This routine must be used in conjunction
 206    --  with Mark_And_Set_xxx routines as well as Set_Ghost_Mode.
 207
 208    procedure Set_Ghost_Mode (N : Node_Or_Entity_Id);
 209    --  Install the Ghost mode of arbitrary node N. This routine starts a Ghost
 210    --  region and must be used in conjunction with Restore_Ghost_Mode.
 211
 212    procedure Set_Is_Ghost_Entity (Id : Entity_Id);
 213    --  Set the relevant Ghost attributes of entity Id depending on the current
 214    --  Ghost assertion policy in effect.
 215
 216 end Ghost;