gcc/except.h

   1 /* Exception Handling interface routines.
   2    Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
   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, 51 Franklin Street, Fifth Floor, Boston, MA
  21 02110-1301, USA.  */
  22
  23
  24 struct function;
  25
  26 /* Per-function EH data.  Used only in except.c, but GC and others
  27    manipulate pointers to the opaque type.  */
  28 struct eh_status;
  29
  30 /* Internal structure describing a region.  */
  31 struct eh_region;
  32
  33 /* Test: is exception handling turned on?  */
  34 extern int doing_eh (int);
  35
  36 /* Note that the current EH region (if any) may contain a throw, or a
  37    call to a function which itself may contain a throw.  */
  38 extern void note_eh_region_may_contain_throw (struct eh_region *);
  39 extern void note_current_region_may_contain_throw (void);
  40
  41 /* Invokes CALLBACK for every exception handler label.  Only used by old
  42    loop hackery; should not be used by new code.  */
  43 extern void for_each_eh_label (void (*) (rtx));
  44
  45 /* Invokes CALLBACK for every exception region in the current function.  */
  46 extern void for_each_eh_region (void (*) (struct eh_region *));
  47
  48 /* Determine if the given INSN can throw an exception.  */
  49 extern bool can_throw_internal_1 (int, bool);
  50 extern bool can_throw_internal (rtx);
  51 extern bool can_throw_external_1 (int, bool);
  52 extern bool can_throw_external (rtx);
  53
  54 /* Set TREE_NOTHROW and cfun->all_throwers_are_sibcalls.  */
  55 extern void set_nothrow_function_flags (void);
  56
  57 /* After initial rtl generation, call back to finish generating
  58    exception support code.  */
  59 extern void finish_eh_generation (void);
  60
  61 extern void init_eh (void);
  62 extern void init_eh_for_function (void);
  63
  64 extern rtx reachable_handlers (rtx);
  65 extern void maybe_remove_eh_handler (rtx);
  66
  67 extern void convert_from_eh_region_ranges (void);
  68 extern void convert_to_eh_region_ranges (void);
  69 extern void find_exception_handler_labels (void);
  70 extern bool current_function_has_exception_handlers (void);
  71 extern void output_function_exception_table (void);
  72
  73 extern void expand_builtin_unwind_init (void);
  74 extern rtx expand_builtin_eh_return_data_regno (tree);
  75 extern rtx expand_builtin_extract_return_addr (tree);
  76 extern void expand_builtin_init_dwarf_reg_sizes (tree);
  77 extern rtx expand_builtin_frob_return_addr (tree);
  78 extern rtx expand_builtin_dwarf_sp_column (void);
  79 extern void expand_builtin_eh_return (tree, tree);
  80 extern void expand_eh_return (void);
  81 extern rtx expand_builtin_extend_pointer (tree);
  82 extern rtx get_exception_pointer (struct function *);
  83 extern rtx get_exception_filter (struct function *);
  84 typedef tree (*duplicate_eh_regions_map) (tree, void *);
  85 extern int duplicate_eh_regions (struct function *, duplicate_eh_regions_map, void *, int);
  86
  87 extern void sjlj_emit_function_exit_after (rtx);
  88
  89 extern struct eh_region *gen_eh_region_cleanup (struct eh_region *,
  90                                                 struct eh_region *);
  91 extern struct eh_region *gen_eh_region_try (struct eh_region *);
  92 extern struct eh_region *gen_eh_region_catch (struct eh_region *, tree);
  93 extern struct eh_region *gen_eh_region_allowed (struct eh_region *, tree);
  94 extern struct eh_region *gen_eh_region_must_not_throw (struct eh_region *);
  95 extern int get_eh_region_number (struct eh_region *);
  96 extern bool get_eh_region_may_contain_throw (struct eh_region *);
  97 extern tree get_eh_region_tree_label (struct eh_region *);
  98 extern void set_eh_region_tree_label (struct eh_region *, tree);
  99
 100 extern void foreach_reachable_handler (int, bool,
 101                                        void (*) (struct eh_region *, void *),
 102                                        void *);
 103
 104 extern void collect_eh_region_array (void);
 105 extern void expand_resx_expr (tree);
 106 extern void verify_eh_tree (struct function *);
 107 extern void dump_eh_tree (FILE *, struct function *);
 108
 109 /* tree-eh.c */
 110 extern void add_stmt_to_eh_region_fn (struct function *, tree, int);
 111 extern bool remove_stmt_from_eh_region_fn (struct function *, tree);
 112 extern int lookup_stmt_eh_region_fn (struct function *, tree);
 113 extern int lookup_stmt_eh_region (tree);
 114 extern bool verify_eh_edges (tree);
 115
 116 /* If non-NULL, this is a function that returns an expression to be
 117    executed if an unhandled exception is propagated out of a cleanup
 118    region.  For example, in C++, an exception thrown by a destructor
 119    during stack unwinding is required to result in a call to
 120    `std::terminate', so the C++ version of this function returns a
 121    CALL_EXPR for `std::terminate'.  */
 122 extern tree (*lang_protect_cleanup_actions) (void);
 123
 124 /* Return true if type A catches type B.  */
 125 extern int (*lang_eh_type_covers) (tree a, tree b);
 126
 127 /* Map a type to a runtime object to match type.  */
 128 extern tree (*lang_eh_runtime_type) (tree);
 129
 130
 131 /* Just because the user configured --with-sjlj-exceptions=no doesn't
 132    mean that we can use call frame exceptions.  Detect that the target
 133    has appropriate support.  */
 134
 135 #ifndef MUST_USE_SJLJ_EXCEPTIONS
 136 # if !(defined (EH_RETURN_DATA_REGNO)                   \
 137        && (defined (TARGET_UNWIND_INFO)                 \
 138            || (DWARF2_UNWIND_INFO                       \
 139                && (defined (EH_RETURN_HANDLER_RTX)      \
 140                    || defined (HAVE_eh_return)))))
 141 #  define MUST_USE_SJLJ_EXCEPTIONS      1
 142 # else
 143 #  define MUST_USE_SJLJ_EXCEPTIONS      0
 144 # endif
 145 #endif
 146
 147 #ifdef CONFIG_SJLJ_EXCEPTIONS
 148 # if CONFIG_SJLJ_EXCEPTIONS == 1
 149 #  define USING_SJLJ_EXCEPTIONS         1
 150 # endif
 151 # if CONFIG_SJLJ_EXCEPTIONS == 0
 152 #  define USING_SJLJ_EXCEPTIONS         0
 153 #  ifndef EH_RETURN_DATA_REGNO
 154     #error "EH_RETURN_DATA_REGNO required"
 155 #  endif
 156 #  if !defined(EH_RETURN_HANDLER_RTX) && !defined(HAVE_eh_return)
 157     #error "EH_RETURN_HANDLER_RTX or eh_return required"
 158 #  endif
 159 #  if !defined(DWARF2_UNWIND_INFO) && !defined(TARGET_UNWIND_INFO)
 160     #error "{DWARF2,TARGET}_UNWIND_INFO required"
 161 #  endif
 162 # endif
 163 #else
 164 # define USING_SJLJ_EXCEPTIONS          MUST_USE_SJLJ_EXCEPTIONS
 165 #endif
 166
 167 struct throw_stmt_node GTY(())
 168 {
 169   tree stmt;
 170   int region_nr;
 171 };
 172
 173 extern struct htab *get_eh_throw_stmt_table (struct function *);
 174 extern void set_eh_throw_stmt_table (struct function *, struct htab *);