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