/* Exception Handling interface routines. Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009 Free Software Foundation, Inc. Contributed by Mike Stump . This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see . */ #include "sbitmap.h" #include "vecprim.h" struct function; /* The type of an exception region. */ enum eh_region_type { ERT_UNKNOWN = 0, ERT_CLEANUP, ERT_TRY, ERT_CATCH, ERT_ALLOWED_EXCEPTIONS, ERT_MUST_NOT_THROW, ERT_THROW }; /* Describes one exception region. */ struct GTY(()) eh_region_d { /* The immediately surrounding region. */ struct eh_region_d *outer; /* The list of immediately contained regions. */ struct eh_region_d *inner; struct eh_region_d *next_peer; /* List of regions sharing label. */ struct eh_region_d *next_region_sharing_label; /* An identifier for this region. */ int region_number; /* When a region is deleted, its parents inherit the REG_EH_REGION numbers already assigned. */ bitmap aka; /* Each region does exactly one thing. */ enum eh_region_type type; /* Holds the action to perform based on the preceding type. */ union eh_region_u { /* A list of catch blocks, a surrounding try block, and the label for continuing after a catch. */ struct eh_region_u_try { struct eh_region_d *eh_catch; struct eh_region_d *last_catch; } GTY ((tag ("ERT_TRY"))) eh_try; /* The list through the catch handlers, the list of type objects matched, and the list of associated filters. */ struct eh_region_u_catch { struct eh_region_d *next_catch; struct eh_region_d *prev_catch; tree type_list; tree filter_list; } GTY ((tag ("ERT_CATCH"))) eh_catch; /* A tree_list of allowed types. */ struct eh_region_u_allowed { tree type_list; int filter; } GTY ((tag ("ERT_ALLOWED_EXCEPTIONS"))) allowed; /* The type given by a call to "throw foo();", or discovered for a throw. */ struct eh_region_u_throw { tree type; } GTY ((tag ("ERT_THROW"))) eh_throw; } GTY ((desc ("%0.type"))) u; /* Entry point for this region's handler before landing pads are built. */ rtx label; tree tree_label; /* Entry point for this region's handler from the runtime eh library. */ rtx landing_pad; /* Entry point for this region's handler from an inner region. */ rtx post_landing_pad; /* The RESX insn for handing off control to the next outermost handler, if appropriate. */ rtx resume; /* True if something in this region may throw. */ unsigned may_contain_throw : 1; }; typedef struct eh_region_d *eh_region; DEF_VEC_P(eh_region); DEF_VEC_ALLOC_P(eh_region, gc); DEF_VEC_ALLOC_P(eh_region, heap); /* Per-function EH data. Used to save exception status for each function. */ struct GTY(()) eh_status { /* The tree of all regions for this function. */ struct eh_region_d *region_tree; /* The same information as an indexable array. */ VEC(eh_region,gc) *region_array; int last_region_number; htab_t GTY((param_is (struct throw_stmt_node))) throw_stmt_table; }; /* Test: is exception handling turned on? */ extern int doing_eh (int); /* Note that the current EH region (if any) may contain a throw, or a call to a function which itself may contain a throw. */ extern void note_eh_region_may_contain_throw (struct eh_region_d *); /* Invokes CALLBACK for every exception handler label. Only used by old loop hackery; should not be used by new code. */ extern void for_each_eh_label (void (*) (rtx)); /* Invokes CALLBACK for every exception region in the current function. */ extern void for_each_eh_region (void (*) (struct eh_region_d *)); /* Determine if the given INSN can throw an exception. */ extern bool can_throw_internal_1 (int, bool, bool); extern bool can_throw_internal (const_rtx); extern bool can_throw_external_1 (int, bool, bool); extern bool can_throw_external (const_rtx); /* Set TREE_NOTHROW and cfun->all_throwers_are_sibcalls. */ extern unsigned int set_nothrow_function_flags (void); extern void init_eh (void); extern void init_eh_for_function (void); extern rtx reachable_handlers (rtx); extern void remove_eh_region (int); extern void remove_eh_region_and_replace_by_outer_of (int, int); extern void convert_from_eh_region_ranges (void); extern unsigned int convert_to_eh_region_ranges (void); extern void find_exception_handler_labels (void); extern bool current_function_has_exception_handlers (void); extern void output_function_exception_table (const char *); extern void expand_builtin_unwind_init (void); extern rtx expand_builtin_eh_return_data_regno (tree); extern rtx expand_builtin_extract_return_addr (tree); extern void expand_builtin_init_dwarf_reg_sizes (tree); extern rtx expand_builtin_frob_return_addr (tree); extern rtx expand_builtin_dwarf_sp_column (void); extern void expand_builtin_eh_return (tree, tree); extern void expand_eh_return (void); extern rtx expand_builtin_extend_pointer (tree); extern rtx get_exception_pointer (void); extern rtx get_exception_filter (void); typedef tree (*duplicate_eh_regions_map) (tree, void *); extern int duplicate_eh_regions (struct function *, duplicate_eh_regions_map, void *, int, int); extern void sjlj_emit_function_exit_after (rtx); extern void default_init_unwind_resume_libfunc (void); extern struct eh_region_d *gen_eh_region_cleanup (struct eh_region_d *); extern struct eh_region_d *gen_eh_region_try (struct eh_region_d *); extern struct eh_region_d *gen_eh_region_catch (struct eh_region_d *, tree); extern struct eh_region_d *gen_eh_region_allowed (struct eh_region_d *, tree); extern struct eh_region_d *gen_eh_region_must_not_throw (struct eh_region_d *); extern int get_eh_region_number (struct eh_region_d *); extern bool get_eh_region_may_contain_throw (struct eh_region_d *); extern tree get_eh_region_no_tree_label (int); extern tree get_eh_region_tree_label (struct eh_region_d *); extern void set_eh_region_tree_label (struct eh_region_d *, tree); extern void foreach_reachable_handler (int, bool, bool, void (*) (struct eh_region_d *, void *), void *); extern void collect_eh_region_array (void); extern void expand_resx_stmt (gimple); extern void verify_eh_tree (struct function *); extern void dump_eh_tree (FILE *, struct function *); void debug_eh_tree (struct function *); extern int eh_region_outermost (struct function *, int, int); extern void add_type_for_runtime (tree); extern tree lookup_type_for_runtime (tree); /* If non-NULL, this is a function that returns an expression to be executed if an unhandled exception is propagated out of a cleanup region. For example, in C++, an exception thrown by a destructor during stack unwinding is required to result in a call to `std::terminate', so the C++ version of this function returns a CALL_EXPR for `std::terminate'. */ extern gimple (*lang_protect_cleanup_actions) (void); /* Return true if type A catches type B. */ extern int (*lang_eh_type_covers) (tree a, tree b); /* Map a type to a runtime object to match type. */ extern tree (*lang_eh_runtime_type) (tree); /* Just because the user configured --with-sjlj-exceptions=no doesn't mean that we can use call frame exceptions. Detect that the target has appropriate support. */ #ifndef MUST_USE_SJLJ_EXCEPTIONS # if defined (EH_RETURN_DATA_REGNO) \ && (defined (TARGET_UNWIND_INFO) \ || (DWARF2_UNWIND_INFO \ && (defined (EH_RETURN_HANDLER_RTX) \ || defined (HAVE_eh_return)))) # define MUST_USE_SJLJ_EXCEPTIONS 0 # else # define MUST_USE_SJLJ_EXCEPTIONS 1 # endif #endif #ifdef CONFIG_SJLJ_EXCEPTIONS # if CONFIG_SJLJ_EXCEPTIONS == 1 # define USING_SJLJ_EXCEPTIONS 1 # endif # if CONFIG_SJLJ_EXCEPTIONS == 0 # define USING_SJLJ_EXCEPTIONS 0 # if !defined(EH_RETURN_DATA_REGNO) #error "EH_RETURN_DATA_REGNO required" # endif # if ! (defined(TARGET_UNWIND_INFO) || DWARF2_UNWIND_INFO) #error "{DWARF2,TARGET}_UNWIND_INFO required" # endif # if !defined(TARGET_UNWIND_INFO) \ && !(defined(EH_RETURN_HANDLER_RTX) || defined(HAVE_eh_return)) #error "EH_RETURN_HANDLER_RTX or eh_return required" # endif /* Usually the above error checks will have already triggered an error, but backends may set MUST_USE_SJLJ_EXCEPTIONS for their own reasons. */ # if MUST_USE_SJLJ_EXCEPTIONS #error "Must use SJLJ exceptions but configured not to" # endif # endif #else # define USING_SJLJ_EXCEPTIONS MUST_USE_SJLJ_EXCEPTIONS #endif struct GTY(()) throw_stmt_node { gimple stmt; int region_nr; }; extern struct htab *get_eh_throw_stmt_table (struct function *); extern void set_eh_throw_stmt_table (struct function *, struct htab *); extern void remove_unreachable_regions (sbitmap, sbitmap); extern VEC(int,heap) * label_to_region_map (void); extern int num_eh_regions (void); extern bitmap must_not_throw_labels (void); extern struct eh_region_d *redirect_eh_edge_to_label (struct edge_def *, tree, bool, bool, int); extern int get_next_region_sharing_label (int);