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 unsigned int 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 unsigned int 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, 86 void *, int, int); 87 88 extern void sjlj_emit_function_exit_after (rtx); 89 extern void default_init_unwind_resume_libfunc (void); 90 91 extern struct eh_region *gen_eh_region_cleanup (struct eh_region *, 92 struct eh_region *); 93 extern struct eh_region *gen_eh_region_try (struct eh_region *); 94 extern struct eh_region *gen_eh_region_catch (struct eh_region *, tree); 95 extern struct eh_region *gen_eh_region_allowed (struct eh_region *, tree); 96 extern struct eh_region *gen_eh_region_must_not_throw (struct eh_region *); 97 extern int get_eh_region_number (struct eh_region *); 98 extern bool get_eh_region_may_contain_throw (struct eh_region *); 99 extern tree get_eh_region_tree_label (struct eh_region *); 100 extern void set_eh_region_tree_label (struct eh_region *, tree); 101 102 extern void foreach_reachable_handler (int, bool, 103 void (*) (struct eh_region *, void *), 104 void *); 105 106 extern void collect_eh_region_array (void); 107 extern void expand_resx_expr (tree); 108 extern void verify_eh_tree (struct function *); 109 extern void dump_eh_tree (FILE *, struct function *); 110 extern bool eh_region_outer_p (struct function *, int, int); 111 extern int eh_region_outermost (struct function *, int, int); 112 113 /* tree-eh.c */ 114 extern void add_stmt_to_eh_region_fn (struct function *, tree, int); 115 extern bool remove_stmt_from_eh_region_fn (struct function *, tree); 116 extern int lookup_stmt_eh_region_fn (struct function *, tree); 117 extern int lookup_stmt_eh_region (tree); 118 extern bool verify_eh_edges (tree); 119 120 /* If non-NULL, this is a function that returns an expression to be 121 executed if an unhandled exception is propagated out of a cleanup 122 region. For example, in C++, an exception thrown by a destructor 123 during stack unwinding is required to result in a call to 124 `std::terminate', so the C++ version of this function returns a 125 CALL_EXPR for `std::terminate'. */ 126 extern tree (*lang_protect_cleanup_actions) (void); 127 128 /* Return true if type A catches type B. */ 129 extern int (*lang_eh_type_covers) (tree a, tree b); 130 131 /* Map a type to a runtime object to match type. */ 132 extern tree (*lang_eh_runtime_type) (tree); 133 134 135 /* Just because the user configured --with-sjlj-exceptions=no doesn't 136 mean that we can use call frame exceptions. Detect that the target 137 has appropriate support. */ 138 139 #ifndef MUST_USE_SJLJ_EXCEPTIONS 140 # if !(defined (EH_RETURN_DATA_REGNO) \ 141 && (defined (TARGET_UNWIND_INFO) \ 142 || (DWARF2_UNWIND_INFO \ 143 && (defined (EH_RETURN_HANDLER_RTX) \ 144 || defined (HAVE_eh_return))))) 145 # define MUST_USE_SJLJ_EXCEPTIONS 1 146 # else 147 # define MUST_USE_SJLJ_EXCEPTIONS 0 148 # endif 149 #endif 150 151 #ifdef CONFIG_SJLJ_EXCEPTIONS 152 # if CONFIG_SJLJ_EXCEPTIONS == 1 153 # define USING_SJLJ_EXCEPTIONS 1 154 # endif 155 # if CONFIG_SJLJ_EXCEPTIONS == 0 156 # define USING_SJLJ_EXCEPTIONS 0 157 # ifndef EH_RETURN_DATA_REGNO 158 #error "EH_RETURN_DATA_REGNO required" 159 # endif 160 # if !defined(EH_RETURN_HANDLER_RTX) && !defined(HAVE_eh_return) 161 #error "EH_RETURN_HANDLER_RTX or eh_return required" 162 # endif 163 # if !defined(DWARF2_UNWIND_INFO) && !defined(TARGET_UNWIND_INFO) 164 #error "{DWARF2,TARGET}_UNWIND_INFO required" 165 # endif 166 # endif 167 #else 168 # define USING_SJLJ_EXCEPTIONS MUST_USE_SJLJ_EXCEPTIONS 169 #endif 170 171 struct throw_stmt_node GTY(()) 172 { 173 tree stmt; 174 int region_nr; 175 }; 176 177 extern struct htab *get_eh_throw_stmt_table (struct function *); 178 extern void set_eh_throw_stmt_table (struct function *, struct htab *); 179 180 #ifdef ENABLE_CHECKING 181 extern void verify_eh_throw_table_statements (void); 182 #endif 183