gcc/ada/sem_prag.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             S E M _ P R A G                              --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2013, 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 --  Pragma handling is isolated in a separate package
  27 --  (logically this processing belongs in chapter 4)
  28
  29 with Namet; use Namet;
  30 with Types; use Types;
  31
  32 package Sem_Prag is
  33
  34    -----------------
  35    -- Subprograms --
  36    -----------------
  37
  38    procedure Analyze_Pragma (N : Node_Id);
  39    --  Analyze procedure for pragma reference node N
  40
  41    procedure Analyze_CTC_In_Decl_Part (N : Node_Id; S : Entity_Id);
  42    --  Special analyze routine for contract-case and test-case pragmas that
  43    --  appears within a declarative part where the pragma is associated with
  44    --  a subprogram specification. N is the pragma node, and S is the entity
  45    --  for the related subprogram. This procedure does a preanalysis of the
  46    --  expressions in the pragma as "spec expressions" (see section in Sem
  47    --  "Handling of Default and Per-Object Expressions...").
  48
  49    procedure Analyze_PPC_In_Decl_Part (N : Node_Id; S : Entity_Id);
  50    --  Special analyze routine for precondition/postcondition pragma that
  51    --  appears within a declarative part where the pragma is associated
  52    --  with a subprogram specification. N is the pragma node, and S is the
  53    --  entity for the related subprogram. This procedure does a preanalysis
  54    --  of the expressions in the pragma as "spec expressions" (see section
  55    --  in Sem "Handling of Default and Per-Object Expressions...").
  56
  57    function Check_Enabled (Nam : Name_Id) return Boolean;
  58    --  This function is used in connection with pragmas Assertion, Check,
  59    --  and assertion aspects and pragmas, to determine if Check pragmas
  60    --  (or corresponding assertion aspects or pragmas) are currently active
  61    --  as determined by the presence of -gnata on the command line (which
  62    --  sets the default), and the appearance of pragmas Check_Policy and
  63    --  Assertion_Policy as configuration pragmas either in a configuration
  64    --  pragma file, or at the start of the current unit, or locally given
  65    --  Check_Policy and Assertion_Policy pragmas that are currently active.
  66    --  True is returned if the specified check is enabled.
  67    --
  68    --  This function knows about all relevant synonyms (e.g. Precondition or
  69    --  Pre can be used to refer to the Pre aspect or Precondition pragma, and
  70    --  Predicate refers to both static and dynamic predicates, and Assertion
  71    --  applies to all assertion aspects and pragmas).
  72    --
  73    --  Note: for assertion kinds Pre'Class, Post'Class, Type_Invariant'Class,
  74    --  the name passed is Name_uPre, Name_uPost, Name_uType_Invariant, which
  75    --  corresponds to _Pre, _Post, _Type_Invariant, which are special names
  76    --  used in identifiers to represent these attribute references.
  77
  78    procedure Check_Applicable_Policy (N : Node_Id);
  79    --  N is either an N_Aspect or an N_Pragma node. There are two cases. If
  80    --  the name of the aspect or pragma is not one of those recognized as a
  81    --  assertion kind by an Assertion_Kind pragma, then the call has no effect.
  82    --  Note that in the case of a pragma derived from an aspect, the name
  83    --  we use for the purpose of this procedure is the aspect name, which may
  84    --  be different from the pragma name (e.g. Precondition for Pre aspect).
  85    --  In addition, 'Class aspects are recognized (and the corresponding
  86    --  special names used in the processing.
  87    --
  88    --  If the name is valid assertion_Kind name, then the Check_Policy pragma
  89    --  chain is checked for a matching entry (or for an Assertion entry which
  90    --  matches all possibilities). If a matching entry is found then the policy
  91    --  is checked. If it is Off, Ignore, or Disable, then the Is_Ignored flag
  92    --  is set in the aspect or pragma node. Additionally for policy Disable,
  93    --  the Is_Disabled flag is set.
  94    --
  95    --  If no matching Check_Policy pragma is found then the effect depends on
  96    --  whether -gnata was used, if so, then the call has no effect, otherwise
  97    --  Is_Ignored (but not Is_Disabled) is set True.
  98
  99    function Delay_Config_Pragma_Analyze (N : Node_Id) return Boolean;
 100    --  N is a pragma appearing in a configuration pragma file. Most such
 101    --  pragmas are analyzed when the file is read, before parsing and analyzing
 102    --  the main unit. However, the analysis of certain pragmas results in
 103    --  adding information to the compiled main unit, and this cannot be done
 104    --  till the main unit is processed. Such pragmas return True from this
 105    --  function and in Frontend pragmas where Delay_Config_Pragma_Analyze is
 106    --  True have their analysis delayed until after the main program is parsed
 107    --  and analyzed.
 108
 109    procedure Initialize;
 110    --  Initializes data structures used for pragma processing. Must be called
 111    --  before analyzing each new main source program.
 112
 113    function Is_Non_Significant_Pragma_Reference (N : Node_Id) return Boolean;
 114    --  The node N is a node for an entity and the issue is whether the
 115    --  occurrence is a reference for the purposes of giving warnings about
 116    --  unreferenced variables. This function returns True if the reference is
 117    --  not a reference from this point of view (e.g. the occurrence in a pragma
 118    --  Pack) and False if it is a real reference (e.g. the occurrence in a
 119    --  pragma Export);
 120
 121    function Is_Pragma_String_Literal (Par : Node_Id) return Boolean;
 122    --  Given an N_Pragma_Argument_Association node, Par, which has the form of
 123    --  an operator symbol, determines whether or not it should be treated as an
 124    --  string literal. This is called by Sem_Ch6.Analyze_Operator_Symbol. If
 125    --  True is returned, the argument is converted to a string literal. If
 126    --  False is returned, then the argument is treated as an entity reference
 127    --  to the operator.
 128
 129    function Is_Config_Static_String (Arg : Node_Id) return Boolean;
 130    --  This is called for a configuration pragma that requires either string
 131    --  literal or a concatenation of string literals. We cannot use normal
 132    --  static string processing because it is too early in the case of the
 133    --  pragma appearing in a configuration pragmas file. If Arg is of an
 134    --  appropriate form, then this call obtains the string (doing any necessary
 135    --  concatenations) and places it in Name_Buffer, setting Name_Len to its
 136    --  length, and then returns True. If it is not of the correct form, then an
 137    --  appropriate error message is posted, and False is returned.
 138
 139    procedure Make_Aspect_For_PPC_In_Gen_Sub_Decl (Decl : Node_Id);
 140    --  This routine makes aspects from precondition or postcondition pragmas
 141    --  that appear within a generic subprogram declaration. Decl is the generic
 142    --  subprogram declaration node. Note that the aspects are attached to the
 143    --  generic copy and also to the orginal tree.
 144
 145    procedure Process_Compilation_Unit_Pragmas (N : Node_Id);
 146    --  Called at the start of processing compilation unit N to deal with any
 147    --  special issues regarding pragmas. In particular, we have to deal with
 148    --  Suppress_All at this stage, since it can appear after the unit instead
 149    --  of before (actually we allow it to appear anywhere).
 150
 151    procedure Set_Encoded_Interface_Name (E : Entity_Id; S : Node_Id);
 152    --  This routine is used to set an encoded interface name. The node S is an
 153    --  N_String_Literal node for the external name to be set, and E is an
 154    --  entity whose Interface_Name field is to be set. In the normal case where
 155    --  S contains a name that is a valid C identifier, then S is simply set as
 156    --  the value of the Interface_Name. Otherwise it is encoded. See the body
 157    --  for details of the encoding. This encoding is only done on VMS systems,
 158    --  since it seems pretty silly, but is needed to pass some dubious tests in
 159    --  the test suite.
 160
 161 end Sem_Prag;