gcc/ada/s-stalib.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --              S Y S T E M . S T A N D A R D _ L I B R A R Y               --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                            $Revision: 1.1 $
  10 --                                                                          --
  11 --          Copyright (C) 1992-2001 Free Software Foundation, Inc.          --
  12 --                                                                          --
  13 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  14 -- terms of the  GNU General Public License as published  by the Free Soft- --
  15 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  16 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  17 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  18 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  19 -- for  more details.  You should have  received  a copy of the GNU General --
  20 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  21 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  22 -- MA 02111-1307, USA.                                                      --
  23 --                                                                          --
  24 -- As a special exception,  if other files  instantiate  generics from this --
  25 -- unit, or you link  this unit with other files  to produce an executable, --
  26 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  27 -- covered  by the  GNU  General  Public  License.  This exception does not --
  28 -- however invalidate  any other reasons why  the executable file  might be --
  29 -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
  31 -- GNAT was originally developed  by the GNAT team at  New York University. --
  32 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  33 --                                                                          --
  34 ------------------------------------------------------------------------------
  35
  36 --  This package is included in all programs. It contains declarations that
  37 --  are required to be part of every Ada program. A special mechanism is
  38 --  required to ensure that these are loaded, since it may be the case in
  39 --  some programs that the only references to these required packages are
  40 --  from C code or from code generated directly by Gigi, an in both cases
  41 --  the binder is not aware of such references.
  42
  43 --  System.Standard_Library also includes data that must be present in every
  44 --  program, in particular the definitions of all the standard and also some
  45 --  subprograms that must be present in every program.
  46
  47 --  The binder unconditionally includes s-stalib.ali, which ensures that this
  48 --  package and the packages it references are included in all Ada programs,
  49 --  together with the included data.
  50
  51 pragma Polling (Off);
  52 --  We must turn polling off for this unit, because otherwise we get
  53 --  elaboration circularities with Ada.Exceptions if polling is on.
  54
  55 with System;
  56 with Unchecked_Conversion;
  57
  58 package System.Standard_Library is
  59
  60    pragma Suppress (All_Checks);
  61    --  Suppress explicitly all the checks to work around the Solaris linker
  62    --  bug when using gnatmake -f -a (but without -gnatp). This is not needed
  63    --  with Solaris 2.6, so eventually can be removed ???
  64
  65    type Big_String_Ptr is access all String (Positive);
  66    --  A non-fat pointer type for null terminated strings
  67
  68    function To_Ptr is
  69      new Unchecked_Conversion (System.Address, Big_String_Ptr);
  70
  71    ---------------------------------------------
  72    -- Type For Enumeration Image Index Tables --
  73    ---------------------------------------------
  74
  75    --  Note: these types are declared at the start of this unit, since
  76    --  they must appear before any enumeration types declared in this
  77    --  unit. Note that the spec of system is already elaborated at
  78    --  this point (since we are a child of system), which means that
  79    --  enumeration types in package System cannot use these types.
  80
  81    type Image_Index_Table_8 is
  82      array (Integer range <>) of Short_Short_Integer;
  83    type Image_Index_Table_16 is
  84      array (Integer range <>) of Short_Integer;
  85    type Image_Index_Table_32 is
  86      array (Integer range <>) of Integer;
  87    --  These types are used to generate the index vector used for enumeration
  88    --  type image tables. See spec of Exp_Imgv in the main GNAT sources for a
  89    --  full description of the data structures that are used here.
  90
  91    -------------------------------------
  92    -- Exception Declarations and Data --
  93    -------------------------------------
  94
  95    type Exception_Data;
  96    type Exception_Data_Ptr is access all Exception_Data;
  97    --  An equivalent of Exception_Id that is public
  98
  99    --  The following record defines the underlying representation of exceptions
 100
 101    --  WARNING! Any changes to this may need to be reflectd in the following
 102    --  locations in the compiler and runtime code:
 103
 104    --    1. The Internal_Exception routine in s-exctab.adb
 105    --    2. The processing in gigi that tests Not_Handled_By_Others
 106    --    3. Expand_N_Exception_Declaration in Exp_Ch11
 107    --    4. The construction of the exception type in Cstand
 108
 109    type Exception_Data is record
 110       Not_Handled_By_Others : Boolean;
 111       --  Normally set False, indicating that the exception is handled in the
 112       --  usual way by others (i.e. an others handler handles the exception).
 113       --  Set True to indicate that this exception is not caught by others
 114       --  handlers, but must be explicitly named in a handler. This latter
 115       --  setting is currently used by the Abort_Signal.
 116
 117       Lang : Character;
 118       --  A character indicating the language raising the exception.
 119       --  Set to "A" for exceptions defined by an Ada program.
 120       --  Set to "V" for imported VMS exceptions.
 121
 122       Name_Length : Natural;
 123       --  Length of fully expanded name of exception
 124
 125       Full_Name : Big_String_Ptr;
 126       --  Fully expanded name of exception, null terminated
 127
 128       HTable_Ptr : Exception_Data_Ptr;
 129       --  Hash table pointer used to link entries together in the hash table
 130       --  built (by Register_Exception in s-exctab.adb) for converting between
 131       --  identities and names.
 132
 133       Import_Code : Integer;
 134       --  Value for imported exceptions. Needed only for the handling of
 135       --  Import/Export_Exception for the VMS case, but present in all
 136       --  implementations (we might well extend this mechanism for other
 137       --  systems in the future).
 138
 139    end record;
 140
 141    --  Definitions for standard predefined exceptions defined in Standard,
 142
 143    --  Why are the Nul's necessary here, seems like they should not be
 144    --  required, since Gigi is supposed to add a Nul to each name ???
 145
 146    Constraint_Error_Name : constant String := "CONSTRAINT_ERROR" & ASCII.NUL;
 147    Program_Error_Name    : constant String := "PROGRAM_ERROR"    & ASCII.NUL;
 148    Storage_Error_Name    : constant String := "STORAGE_ERROR"    & ASCII.NUL;
 149    Tasking_Error_Name    : constant String := "TASKING_ERROR"    & ASCII.NUL;
 150    Abort_Signal_Name     : constant String := "_ABORT_SIGNAL"    & ASCII.NUL;
 151
 152    Numeric_Error_Name    : constant String := "NUMERIC_ERROR"    & ASCII.NUL;
 153    --  This is used only in the Ada 83 case, but it is not worth having a
 154    --  separate version of s-stalib.ads for use in Ada 83 mode.
 155
 156    Constraint_Error_Def : aliased Exception_Data :=
 157      (Not_Handled_By_Others => False,
 158       Lang                  => 'A',
 159       Name_Length           => Constraint_Error_Name'Length,
 160       Full_Name             => To_Ptr (Constraint_Error_Name'Address),
 161       HTable_Ptr            => null,
 162       Import_Code           => 0);
 163
 164    Numeric_Error_Def : aliased Exception_Data :=
 165      (Not_Handled_By_Others => False,
 166       Lang                  => 'A',
 167       Name_Length           => Numeric_Error_Name'Length,
 168       Full_Name             => To_Ptr (Numeric_Error_Name'Address),
 169       HTable_Ptr            => null,
 170       Import_Code           => 0);
 171
 172    Program_Error_Def : aliased Exception_Data :=
 173      (Not_Handled_By_Others => False,
 174       Lang                  => 'A',
 175       Name_Length           => Program_Error_Name'Length,
 176       Full_Name             => To_Ptr (Program_Error_Name'Address),
 177       HTable_Ptr            => null,
 178       Import_Code           => 0);
 179
 180    Storage_Error_Def : aliased Exception_Data :=
 181      (Not_Handled_By_Others => False,
 182       Lang                  => 'A',
 183       Name_Length           => Storage_Error_Name'Length,
 184       Full_Name             => To_Ptr (Storage_Error_Name'Address),
 185       HTable_Ptr            => null,
 186       Import_Code           => 0);
 187
 188    Tasking_Error_Def : aliased Exception_Data :=
 189      (Not_Handled_By_Others => False,
 190       Lang                  => 'A',
 191       Name_Length           => Tasking_Error_Name'Length,
 192       Full_Name             => To_Ptr (Tasking_Error_Name'Address),
 193       HTable_Ptr            => null,
 194       Import_Code           => 0);
 195
 196    Abort_Signal_Def : aliased Exception_Data :=
 197      (Not_Handled_By_Others => True,
 198       Lang                  => 'A',
 199       Name_Length           => Abort_Signal_Name'Length,
 200       Full_Name             => To_Ptr (Abort_Signal_Name'Address),
 201       HTable_Ptr            => null,
 202       Import_Code           => 0);
 203
 204    pragma Export (C, Constraint_Error_Def, "constraint_error");
 205    pragma Export (C, Numeric_Error_Def,    "numeric_error");
 206    pragma Export (C, Program_Error_Def,    "program_error");
 207    pragma Export (C, Storage_Error_Def,    "storage_error");
 208    pragma Export (C, Tasking_Error_Def,    "tasking_error");
 209    pragma Export (C, Abort_Signal_Def,     "_abort_signal");
 210
 211    Local_Partition_ID : Natural := 0;
 212    --  This variable contains the local Partition_ID that will be used when
 213    --  building exception occurrences. In distributed mode, it will be
 214    --  set by each partition to the correct value during the elaboration.
 215
 216    type Exception_Trace_Kind is
 217      (RM_Convention,
 218       --  No particular trace is requested, only unhandled exceptions
 219       --  in the environment task (following the RM) will be printed.
 220       --  This is the default behavior.
 221
 222       Every_Raise,
 223       --  Denotes every possible raise event, either explicit or due to
 224       --  a specific language rule, within the context of a task or not.
 225
 226       Unhandled_Raise
 227       --  Denotes the raise events corresponding to exceptions for which
 228       --  there is no user defined handler.
 229      );
 230    --  Provide a way to denote different kinds of automatic traces related
 231    --  to exceptions that can be requested.
 232
 233    Exception_Trace : Exception_Trace_Kind := RM_Convention;
 234    pragma Atomic (Exception_Trace);
 235    --  By default, follow the RM convention.
 236
 237    -----------------
 238    -- Subprograms --
 239    -----------------
 240
 241    procedure Abort_Undefer_Direct;
 242    pragma Inline (Abort_Undefer_Direct);
 243    --  A little procedure that just calls Abort_Undefer.all, for use in
 244    --  clean up procedures, which only permit a simple subprogram name.
 245
 246    procedure Adafinal;
 247    --  Performs the Ada Runtime finalization the first time it is invoked.
 248    --  All subsequent calls are ignored.
 249
 250 end System.Standard_Library;