gcc/except.h

   1 /* Exception Handling interface routines.
   2    Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002
   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 GCC_VARRAY_H
  25 struct varray_head_tag;
  26 #define varray_type struct varray_head_tag *
  27 #endif
  28
  29 struct function;
  30
  31 struct inline_remap;
  32
  33 /* Per-function EH data.  Used only in except.c, but GC and others
  34    manipulate pointers to the opaque type.  */
  35 struct eh_status;
  36
  37 /* Internal structure describing a region.  */
  38 struct eh_region;
  39
  40 /* Test: is exception handling turned on?  */
  41 extern int doing_eh                             PARAMS ((int));
  42
  43 /* Start an exception handling region.  All instructions emitted after
  44    this point are considered to be part of the region until an
  45    expand_eh_region_end variant is invoked.  */
  46 extern void expand_eh_region_start              PARAMS ((void));
  47
  48 /* End an exception handling region for a cleanup.  HANDLER is an
  49    expression to expand for the cleanup.  */
  50 extern void expand_eh_region_end_cleanup        PARAMS ((tree));
  51
  52 /* End an exception handling region for a try block, and prepares
  53    for subsequent calls to expand_start_catch.  */
  54 extern void expand_start_all_catch              PARAMS ((void));
  55
  56 /* Begin a catch clause.  TYPE is an object to be matched by the
  57    runtime, or a list of such objects, or null if this is a catch-all
  58    clause.  */
  59 extern void expand_start_catch                  PARAMS ((tree));
  60
  61 /* End a catch clause.  Control will resume after the try/catch block.  */
  62 extern void expand_end_catch                    PARAMS ((void));
  63
  64 /* End a sequence of catch handlers for a try block.  */
  65 extern void expand_end_all_catch                PARAMS ((void));
  66
  67 /* End an exception region for an exception type filter.  ALLOWED is a
  68    TREE_LIST of TREE_VALUE objects to be matched by the runtime.
  69    FAILURE is a function to invoke if a mismatch occurs.  */
  70 extern void expand_eh_region_end_allowed        PARAMS ((tree, tree));
  71
  72 /* End an exception region for a must-not-throw filter.  FAILURE is a
  73    function to invoke if an uncaught exception propagates this far.  */
  74 extern void expand_eh_region_end_must_not_throw PARAMS ((tree));
  75
  76 /* End an exception region for a throw.  No handling goes on here,
  77    but it's the easiest way for the front-end to indicate what type
  78    is being thrown.  */
  79 extern void expand_eh_region_end_throw          PARAMS ((tree));
  80
  81 /* End a fixup region.  Within this region the cleanups for the immediately
  82    enclosing region are _not_ run.  This is used for goto cleanup to avoid
  83    destroying an object twice.  */
  84 extern void expand_eh_region_end_fixup          PARAMS ((tree));
  85
  86 /* Begin a region that will contain entries created with
  87    add_partial_entry.  */
  88 extern void begin_protect_partials              PARAMS ((void));
  89
  90 /* Create a new exception region and add the handler for the region
  91    onto a list. These regions will be ended (and their handlers emitted)
  92    when end_protect_partials is invoked.  */
  93 extern void add_partial_entry                   PARAMS ((tree));
  94
  95 /* End all of the pending exception regions that have handlers added with
  96    add_partial_entry.  */
  97 extern void end_protect_partials                PARAMS ((void));
  98
  99 /* Invokes CALLBACK for every exception handler label.  Only used by old
 100    loop hackery; should not be used by new code.  */
 101 extern void for_each_eh_label                   PARAMS ((void (*) (rtx)));
 102
 103 /* Determine if the given INSN can throw an exception.  */
 104 extern bool can_throw_internal                  PARAMS ((rtx));
 105 extern bool can_throw_external                  PARAMS ((rtx));
 106
 107 /* Return nonzero if nothing in this function can throw.  */
 108 extern bool nothrow_function_p                  PARAMS ((void));
 109
 110 /* After initial rtl generation, call back to finish generating
 111    exception support code.  */
 112 extern void finish_eh_generation                PARAMS ((void));
 113
 114 extern void init_eh                             PARAMS ((void));
 115 extern void init_eh_for_function                PARAMS ((void));
 116
 117 extern rtx reachable_handlers                   PARAMS ((rtx));
 118 extern void maybe_remove_eh_handler             PARAMS ((rtx));
 119
 120 extern void convert_from_eh_region_ranges       PARAMS ((void));
 121 extern void convert_to_eh_region_ranges         PARAMS ((void));
 122 extern void find_exception_handler_labels       PARAMS ((void));
 123 extern bool current_function_has_exception_handlers PARAMS ((void));
 124 extern void output_function_exception_table     PARAMS ((void));
 125
 126 extern void expand_builtin_unwind_init          PARAMS ((void));
 127 extern rtx expand_builtin_eh_return_data_regno  PARAMS ((tree));
 128 extern rtx expand_builtin_extract_return_addr   PARAMS ((tree));
 129 extern void expand_builtin_init_dwarf_reg_sizes PARAMS ((tree));
 130 extern rtx expand_builtin_frob_return_addr      PARAMS ((tree));
 131 extern rtx expand_builtin_dwarf_fp_regnum       PARAMS ((void));
 132 extern void expand_builtin_eh_return            PARAMS ((tree, tree));
 133 extern void expand_eh_return                    PARAMS ((void));
 134 extern rtx get_exception_pointer                PARAMS ((struct function *));
 135 extern int duplicate_eh_regions                 PARAMS ((struct function *,
 136                                                  struct inline_remap *));
 137
 138 extern void sjlj_emit_function_exit_after       PARAMS ((rtx));
 139
 140
 141 /* If non-NULL, this is a function that returns an expression to be
 142    executed if an unhandled exception is propagated out of a cleanup
 143    region.  For example, in C++, an exception thrown by a destructor
 144    during stack unwinding is required to result in a call to
 145    `std::terminate', so the C++ version of this function returns a
 146    CALL_EXPR for `std::terminate'.  */
 147 extern tree (*lang_protect_cleanup_actions) PARAMS ((void));
 148
 149 /* Return true if type A catches type B.  */
 150 extern int (*lang_eh_type_covers) PARAMS ((tree a, tree b));
 151
 152 /* Map a type to a runtime object to match type.  */
 153 extern tree (*lang_eh_runtime_type) PARAMS ((tree));
 154
 155 #ifndef GCC_VARRAY_H
 156 #undef varray_type
 157 #endif
 158
 159
 160 /* Just because the user configured --with-sjlj-exceptions=no doesn't
 161    mean that we can use call frame exceptions.  Detect that the target
 162    has appropriate support.  */
 163
 164 #if ! (defined (EH_RETURN_DATA_REGNO)                   \
 165        && (defined (IA64_UNWIND_INFO)                   \
 166            || (DWARF2_UNWIND_INFO                       \
 167                && defined (EH_RETURN_STACKADJ_RTX)      \
 168                && (defined (EH_RETURN_HANDLER_RTX)      \
 169                    || defined (HAVE_eh_return)))))
 170 #define MUST_USE_SJLJ_EXCEPTIONS        1
 171 #else
 172 #define MUST_USE_SJLJ_EXCEPTIONS        0
 173 #endif
 174
 175 #ifdef CONFIG_SJLJ_EXCEPTIONS
 176 # if CONFIG_SJLJ_EXCEPTIONS == 1
 177 #  define USING_SJLJ_EXCEPTIONS         1
 178 # endif
 179 # if CONFIG_SJLJ_EXCEPTIONS == 0
 180 #  define USING_SJLJ_EXCEPTIONS         0
 181 #  ifndef EH_RETURN_DATA_REGNO
 182     #error "EH_RETURN_DATA_REGNO required"
 183 #  endif
 184 #  ifndef EH_RETURN_STACKADJ_RTX
 185     #error "EH_RETURN_STACKADJ_RTX required"
 186 #  endif
 187 #  if !defined(EH_RETURN_HANDLER_RTX) && !defined(HAVE_eh_return)
 188     #error "EH_RETURN_HANDLER_RTX or eh_return required"
 189 #  endif
 190 #  if !defined(DWARF2_UNWIND_INFO) && !defined(IA64_UNWIND_INFO)
 191     #error "{DWARF2,IA64}_UNWIND_INFO required"
 192 #  endif
 193 # endif
 194 #else
 195 # define USING_SJLJ_EXCEPTIONS          MUST_USE_SJLJ_EXCEPTIONS
 196 #endif