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) 2014-2021, 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 Check_Ghost_Completion
  35      (Prev_Id  : Entity_Id;
  36       Compl_Id : Entity_Id);
  37    --  Verify that the Ghost policy of initial entity Prev_Id is compatible
  38    --  with the Ghost policy of completing entity Compl_Id. Emit an error if
  39    --  this is not the case.
  40
  41    procedure Check_Ghost_Context
  42      (Ghost_Id  : Entity_Id;
  43       Ghost_Ref : Node_Id);
  44    --  Determine whether node Ghost_Ref appears within a Ghost-friendly context
  45    --  where Ghost entity Ghost_Id can safely reside.
  46
  47    procedure Check_Ghost_Overriding
  48      (Subp            : Entity_Id;
  49       Overridden_Subp : Entity_Id);
  50    --  Verify that the Ghost policy of parent subprogram Overridden_Subp is
  51    --  compatible with the Ghost policy of overriding subprogram Subp. Emit
  52    --  an error if this is not the case.
  53
  54    procedure Check_Ghost_Primitive (Prim : Entity_Id; Typ : Entity_Id);
  55    --  Verify that the Ghost policy of primitive operation Prim is the same as
  56    --  the Ghost policy of tagged type Typ. Emit an error if this is not the
  57    --  case.
  58
  59    procedure Check_Ghost_Refinement
  60      (State      : Node_Id;
  61       State_Id   : Entity_Id;
  62       Constit    : Node_Id;
  63       Constit_Id : Entity_Id);
  64    --  Verify that the Ghost policy of constituent Constit_Id is compatible
  65    --  with the Ghost policy of abstract state State_I.
  66
  67    procedure Check_Ghost_Type (Typ : Entity_Id);
  68    --  Verify that Ghost type Typ is neither concurrent, nor effectively
  69    --  volatile.
  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_Region (Mode : Ghost_Mode_Type; N : Node_Id);
  78    pragma Inline (Install_Ghost_Region);
  79    --  Install a Ghost region described by mode Mode and ignored region start
  80    --  node N.
  81
  82    function Is_Ghost_Assignment (N : Node_Id) return Boolean;
  83    --  Determine whether arbitrary node N denotes an assignment statement whose
  84    --  target is a Ghost entity.
  85
  86    function Is_Ghost_Declaration (N : Node_Id) return Boolean;
  87    --  Determine whether arbitrary node N denotes a declaration which defines
  88    --  a Ghost entity.
  89
  90    function Is_Ghost_Pragma (N : Node_Id) return Boolean;
  91    --  Determine whether arbitrary node N denotes a pragma which encloses a
  92    --  Ghost entity or is associated with a Ghost entity.
  93
  94    function Is_Ghost_Procedure_Call (N : Node_Id) return Boolean;
  95    --  Determine whether arbitrary node N denotes a procedure call invoking a
  96    --  Ghost procedure.
  97
  98    function Is_Ignored_Ghost_Unit (N : Node_Id) return Boolean;
  99    --  Determine whether compilation unit N is subject to pragma Ghost with
 100    --  policy Ignore.
 101
 102    procedure Lock;
 103    --  Lock internal tables before calling backend
 104
 105    procedure Mark_And_Set_Ghost_Assignment (N : Node_Id);
 106    --  Mark assignment statement N as Ghost when:
 107    --
 108    --    * The left hand side denotes a Ghost entity
 109    --
 110    --  Install the Ghost mode of the assignment statement. This routine starts
 111    --  a Ghost region and must be used with routine Restore_Ghost_Region.
 112
 113    procedure Mark_And_Set_Ghost_Body
 114      (N       : Node_Id;
 115       Spec_Id : Entity_Id);
 116    --  Mark package or subprogram body N as Ghost when:
 117    --
 118    --    * The body is subject to pragma Ghost
 119    --
 120    --    * The body completes a previous declaration whose spec denoted by
 121    --      Spec_Id is a Ghost entity.
 122    --
 123    --    * The body appears within a Ghost region
 124    --
 125    --  Install the Ghost mode of the body. This routine starts a Ghost region
 126    --  and must be used with routine Restore_Ghost_Region.
 127
 128    procedure Mark_And_Set_Ghost_Completion
 129      (N       : Node_Id;
 130       Prev_Id : Entity_Id);
 131    --  Mark completion N of a deferred constant or private type [extension]
 132    --  Ghost when:
 133    --
 134    --    * The entity of the previous declaration denoted by Prev_Id is Ghost
 135    --
 136    --    * The completion appears within a Ghost region
 137    --
 138    --  Install the Ghost mode of the completion. This routine starts a Ghost
 139    --  region and must be used with routine Restore_Ghost_Region.
 140
 141    procedure Mark_And_Set_Ghost_Declaration (N : Node_Id);
 142    --  Mark declaration N as Ghost when:
 143    --
 144    --    * The declaration is subject to pragma Ghost
 145    --
 146    --    * The declaration denotes a child package or subprogram and the parent
 147    --      is a Ghost unit.
 148    --
 149    --    * The declaration appears within a Ghost region
 150    --
 151    --  Install the Ghost mode of the declaration. This routine starts a Ghost
 152    --  region and must be used with routine Restore_Ghost_Region.
 153
 154    procedure Mark_And_Set_Ghost_Instantiation
 155      (N      : Node_Id;
 156       Gen_Id : Entity_Id);
 157    --  Mark instantiation N as Ghost when:
 158    --
 159    --    * The instantiation is subject to pragma Ghost
 160    --
 161    --    * The generic template denoted by Gen_Id is Ghost
 162    --
 163    --    * The instantiation appears within a Ghost region
 164    --
 165    --  Install the Ghost mode of the instantiation. This routine starts a Ghost
 166    --  region and must be used with routine Restore_Ghost_Region.
 167
 168    procedure Mark_And_Set_Ghost_Procedure_Call (N : Node_Id);
 169    --  Mark procedure call N as Ghost when:
 170    --
 171    --    * The procedure being invoked is a Ghost entity
 172    --
 173    --  Install the Ghost mode of the procedure call. This routine starts a
 174    --  Ghost region and must be used with routine Restore_Ghost_Region.
 175
 176    procedure Mark_Ghost_Clause (N : Node_Id);
 177    --  Mark use package, use type, or with clause N as Ghost when:
 178    --
 179    --    * The clause mentions a Ghost entity
 180
 181    procedure Mark_Ghost_Pragma
 182      (N  : Node_Id;
 183       Id : Entity_Id);
 184    --  Mark pragma N as Ghost when:
 185    --
 186    --    * The pragma encloses Ghost entity Id
 187    --
 188    --    * The pragma is associated with Ghost entity Id
 189
 190    procedure Mark_Ghost_Renaming
 191      (N  : Node_Id;
 192       Id : Entity_Id);
 193    --  Mark renaming declaration N as Ghost when:
 194    --
 195    --    * Renamed entity Id denotes a Ghost entity
 196
 197    procedure Remove_Ignored_Ghost_Code;
 198    --  Remove all code marked as ignored Ghost from the trees of all qualifying
 199    --  units (SPARK RM 6.9(4)).
 200    --
 201    --  WARNING: this is a separate front end pass, care should be taken to keep
 202    --  it optimized.
 203
 204    procedure Restore_Ghost_Region (Mode : Ghost_Mode_Type; N : Node_Id);
 205    pragma Inline (Restore_Ghost_Region);
 206    --  Restore a Ghost region to a previous state described by mode Mode and
 207    --  ignored region start node N. This routine must be used in conjunction
 208    --  with the following routines:
 209    --
 210    --    Install_Ghost_Region
 211    --    Mark_And_Set_xxx
 212    --    Set_Ghost_Mode
 213
 214    procedure Set_Ghost_Mode (N : Node_Or_Entity_Id);
 215    --  Install the Ghost mode of arbitrary node N. This routine starts a Ghost
 216    --  region and must be used with routine Restore_Ghost_Region.
 217
 218    procedure Set_Is_Ghost_Entity (Id : Entity_Id);
 219    --  Set the relevant Ghost attributes of entity Id depending on the current
 220    --  Ghost assertion policy in effect.
 221
 222 end Ghost;