gcc/except.h

   1 /* Exception Handling interface routines.
   2    Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001
   3    Free Software Foundation, Inc.
   4    Contributed by Mike Stump <mrs@cygnus.com>.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 2, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING.  If not, write to the Free
  20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  21 02111-1307, USA.  */
  22
  23
  24 #ifndef TREE_CODE
  25 union tree_node;
  26 #define tree union tree_node *
  27 #endif
  28
  29 #ifndef RTX_CODE
  30 struct rtx_def;
  31 #define rtx struct rtx_def *
  32 #endif
  33
  34 #ifndef GCC_VARRAY_H
  35 struct varray_head_tag;
  36 #define varray_type struct varray_head_tag *
  37 #endif
  38
  39
  40 /* Per-function EH data.  Used only in except.c, but GC and others
  41    manipulate pointers to the opaque type.  */
  42 struct eh_status;
  43
  44 /* Internal structure describing a region.  */
  45 struct eh_region;
  46
  47 /* Test: is exception handling turned on?  */
  48 extern int doing_eh                             PARAMS ((int));
  49
  50 /* Start an exception handling region.  All instructions emitted after
  51    this point are considered to be part of the region until an
  52    expand_eh_region_end variant is invoked.  */
  53 extern void expand_eh_region_start              PARAMS ((void));
  54
  55 /* End an exception handling region for a cleanup.  HANDLER is an
  56    expression to expand for the cleanup.  */
  57 extern void expand_eh_region_end_cleanup        PARAMS ((tree));
  58
  59 /* End an exception handling region for a try block, and prepares
  60    for subsequent calls to expand_start_catch.  */
  61 extern void expand_start_all_catch              PARAMS ((void));
  62
  63 /* Begin a catch clause.  TYPE is an object to be matched by the
  64    runtime, or null if this is a catch-all clause.  */
  65 extern void expand_start_catch                  PARAMS ((tree));
  66
  67 /* End a catch clause.  Control will resume after the try/catch block.  */
  68 extern void expand_end_catch                    PARAMS ((void));
  69
  70 /* End a sequence of catch handlers for a try block.  */
  71 extern void expand_end_all_catch                PARAMS ((void));
  72
  73 /* End an exception region for an exception type filter.  ALLOWED is a
  74    TREE_LIST of TREE_VALUE objects to be matched by the runtime.
  75    FAILURE is a function to invoke if a mismatch ocurrs.  */
  76 extern void expand_eh_region_end_allowed        PARAMS ((tree, tree));
  77
  78 /* End an exception region for a must-not-throw filter.  FAILURE is a
  79    function to invoke if an uncaught exception propagates this far.  */
  80 extern void expand_eh_region_end_must_not_throw PARAMS ((tree));
  81
  82 /* End an exception region for a throw.  No handling goes on here,
  83    but it's the easiest way for the front-end to indicate what type
  84    is being thrown.  */
  85 extern void expand_eh_region_end_throw          PARAMS ((tree));
  86
  87 /* End a fixup region.  Within this region the cleanups for the immediately
  88    enclosing region are _not_ run.  This is used for goto cleanup to avoid
  89    destroying an object twice.  */
  90 extern void expand_eh_region_end_fixup          PARAMS ((tree));
  91
  92 /* Begin a region that will contain entries created with
  93    add_partial_entry.  */
  94 extern void begin_protect_partials              PARAMS ((void));
  95
  96 /* Create a new exception region and add the handler for the region
  97    onto a list. These regions will be ended (and their handlers emitted)
  98    when end_protect_partials is invoked.  */
  99 extern void add_partial_entry                   PARAMS ((tree));
 100
 101 /* End all of the pending exception regions that have handlers added with
 102    add_partial_entry.  */
 103 extern void end_protect_partials                PARAMS ((void));
 104
 105
 106 /* A list of labels used for exception handlers.  */
 107 extern rtx exception_handler_labels;
 108
 109 /* Determine if the given INSN can throw an exception.  */
 110 extern bool can_throw_internal                  PARAMS ((rtx));
 111 extern bool can_throw_external                  PARAMS ((rtx));
 112
 113 /* Return nonzero if nothing in this function can throw.  */
 114 extern bool nothrow_function_p                  PARAMS ((void));
 115
 116 /* After initial rtl generation, call back to finish generating
 117    exception support code.  */
 118 extern void finish_eh_generation                PARAMS ((void));
 119
 120 extern void init_eh                             PARAMS ((void));
 121 extern void init_eh_for_function                PARAMS ((void));
 122
 123 extern rtx reachable_handlers                   PARAMS ((rtx));
 124 extern void maybe_remove_eh_handler             PARAMS ((rtx));
 125
 126 extern void convert_from_eh_region_ranges       PARAMS ((void));
 127 extern void convert_to_eh_region_ranges         PARAMS ((void));
 128 extern void find_exception_handler_labels       PARAMS ((void));
 129 extern void output_function_exception_table     PARAMS ((void));
 130
 131 extern void expand_builtin_unwind_init          PARAMS ((void));
 132 extern rtx expand_builtin_eh_return_data_regno  PARAMS ((tree));
 133 extern rtx expand_builtin_extract_return_addr   PARAMS ((tree));
 134 extern void expand_builtin_init_dwarf_reg_sizes PARAMS ((tree));
 135 extern rtx expand_builtin_frob_return_addr      PARAMS ((tree));
 136 extern rtx expand_builtin_dwarf_fp_regnum       PARAMS ((void));
 137 extern void expand_builtin_eh_return            PARAMS ((tree, tree));
 138 extern void expand_eh_return                    PARAMS ((void));
 139
 140 extern rtx get_exception_pointer                PARAMS ((struct function *));
 141
 142 struct function;
 143 struct inline_remap;
 144 extern int duplicate_eh_regions         PARAMS ((struct function *,
 145                                                  struct inline_remap *));
 146
 147 extern void sjlj_emit_function_exit_after       PARAMS ((rtx));
 148
 149
 150 /* If non-NULL, this is a function that returns an expression to be
 151    executed if an unhandled exception is propogated out of a cleanup
 152    region.  For example, in C++, an exception thrown by a destructor
 153    during stack unwinding is required to result in a call to
 154    `std::terminate', so the C++ version of this function returns a
 155    CALL_EXPR for `std::terminate'.  */
 156 extern tree (*lang_protect_cleanup_actions) PARAMS ((void));
 157
 158 /* Return true if type A catches type B.  */
 159 extern int (*lang_eh_type_covers) PARAMS ((tree a, tree b));
 160
 161 /* Map a type to a runtime object to match type.  */
 162 extern tree (*lang_eh_runtime_type) PARAMS ((tree));
 163
 164 #ifndef TREE_CODE
 165 #undef tree
 166 #endif
 167
 168 #ifndef RTX_CODE
 169 #undef rtx
 170 #endif
 171
 172 #ifndef GCC_VARRAY_H
 173 #undef varray_type
 174 #endif
 175
 176
 177 /* Just because the user configured --with-sjlj-exceptions=no doesn't
 178    mean that we can use call frame exceptions.  Detect that the target
 179    has appropriate support.  */
 180
 181 #if ! (defined (EH_RETURN_DATA_REGNO)                   \
 182        && (defined (IA64_UNWIND_INFO)                   \
 183            || (DWARF2_UNWIND_INFO                       \
 184                && defined (EH_RETURN_STACKADJ_RTX)      \
 185                && (defined (EH_RETURN_HANDLER_RTX)      \
 186                    || defined (HAVE_eh_return)))))
 187 #define MUST_USE_SJLJ_EXCEPTIONS        1
 188 #else
 189 #define MUST_USE_SJLJ_EXCEPTIONS        0
 190 #endif
 191
 192 #ifdef CONFIG_SJLJ_EXCEPTIONS
 193 # if CONFIG_SJLJ_EXCEPTIONS == 1
 194 #  define USING_SJLJ_EXCEPTIONS         1
 195 # endif
 196 # if CONFIG_SJLJ_EXCEPTIONS == 0
 197 #  define USING_SJLJ_EXCEPTIONS         0
 198 #  ifndef EH_RETURN_DATA_REGNO
 199     #error "EH_RETURN_DATA_REGNO required"
 200 #  endif
 201 #  ifndef EH_RETURN_STACKADJ_RTX
 202     #error "EH_RETURN_STACKADJ_RTX required"
 203 #  endif
 204 #  if !defined(EH_RETURN_HANDLER_RTX) && !defined(HAVE_eh_return)
 205     #error "EH_RETURN_HANDLER_RTX or eh_return required"
 206 #  endif
 207 #  if !defined(DWARF2_UNWIND_INFO) && !defined(IA64_UNWIND_INFO)
 208     #error "{DWARF2,IA64}_UNWIND_INFO required"
 209 #  endif
 210 # endif
 211 #else
 212 # define USING_SJLJ_EXCEPTIONS          MUST_USE_SJLJ_EXCEPTIONS
 213 #endif