/* Exception Handling interface routines.
- Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
+ Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
+ 2007, 2008 Free Software Foundation, Inc.
Contributed by Mike Stump <mrs@cygnus.com>.
-This file is part of GNU CC.
+This file is part of GCC.
-GNU CC 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 2, or (at your option)
-any later version.
+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.
-GNU CC 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.
+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 GNU CC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+#include "sbitmap.h"
+#include "vecprim.h"
-#ifndef TREE_CODE
-union tree_node;
-#define tree union tree_node *
-#endif
-
-#ifndef RTX_CODE
-struct rtx_def;
-#define rtx struct rtx_def *
-#endif
-
-#ifndef _VARRAY_H_
-struct varray_head_tag;
-#define varray_type struct varray_head_tag *
-#endif
-
+struct function;
-/* Per-function EH data. Used only in except.c, but GC and others
- manipulate pointers to the opaque type. */
-struct eh_status;
+/* Describes one exception region. */
+struct GTY(()) eh_region
+{
+ /* The immediately surrounding region. */
+ struct eh_region *outer;
+
+ /* The list of immediately contained regions. */
+ struct eh_region *inner;
+ struct eh_region *next_peer;
+
+ /* List of regions sharing label. */
+ struct eh_region *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
+ {
+ ERT_UNKNOWN = 0,
+ ERT_CLEANUP,
+ ERT_TRY,
+ ERT_CATCH,
+ ERT_ALLOWED_EXCEPTIONS,
+ ERT_MUST_NOT_THROW,
+ ERT_THROW
+ } 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 *eh_catch;
+ struct eh_region *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 *next_catch;
+ struct eh_region *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;
+
+ /* Retain the cleanup expression even after expansion so that
+ we can match up fixup regions. */
+ struct eh_region_u_cleanup {
+ struct eh_region *prev_try;
+ } GTY ((tag ("ERT_CLEANUP"))) cleanup;
+ } 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 *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 *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;
+};
-/* Internal structure describing a region. */
-struct eh_region;
/* Test: is exception handling turned on? */
-extern int doing_eh PARAMS ((int));
-
-/* Start an exception handling region. All instructions emitted after
- this point are considered to be part of the region until an
- expand_eh_region_end variant is invoked. */
-extern void expand_eh_region_start PARAMS ((void));
-
-/* End an exception handling region for a cleanup. HANDLER is an
- expression to expand for the cleanup. */
-extern void expand_eh_region_end_cleanup PARAMS ((tree));
-
-/* End an exception handling region for a try block, and prepares
- for subsequent calls to expand_start_catch. */
-extern void expand_start_all_catch PARAMS ((void));
+extern int doing_eh (int);
-/* Begin a catch clause. TYPE is an object to be matched by the
- runtime, or null if this is a catch-all clause. */
-extern void expand_start_catch PARAMS ((tree));
+/* 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 *);
-/* End a catch clause. Control will resume after the try/catch block. */
-extern void expand_end_catch PARAMS ((void));
+/* 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));
-/* End a sequence of catch handlers for a try block. */
-extern void expand_end_all_catch PARAMS ((void));
-
-/* End an exception region for an exception type filter. ALLOWED is a
- TREE_LIST of TREE_VALUE objects to be matched by the runtime.
- FAILURE is a function to invoke if a mismatch ocurrs. */
-extern void expand_eh_region_end_allowed PARAMS ((tree, tree));
-
-/* End an exception region for a must-not-throw filter. FAILURE is a
- function to invoke if an uncaught exception propagates this far. */
-extern void expand_eh_region_end_must_not_throw PARAMS ((tree));
-
-/* End an exception region for a throw. No handling goes on here,
- but it's the easiest way for the front-end to indicate what type
- is being thrown. */
-extern void expand_eh_region_end_throw PARAMS ((tree));
-
-/* End a fixup region. Within this region the cleanups for the immediately
- enclosing region are _not_ run. This is used for goto cleanup to avoid
- destroying an object twice. */
-extern void expand_eh_region_end_fixup PARAMS ((tree));
-
-/* Begin a region that will contain entries created with
- add_partial_entry. */
-extern void begin_protect_partials PARAMS ((void));
-
-/* Create a new exception region and add the handler for the region
- onto a list. These regions will be ended (and their handlers emitted)
- when end_protect_partials is invoked. */
-extern void add_partial_entry PARAMS ((tree));
-
-/* End all of the pending exception regions that have handlers added with
- add_partial_entry. */
-extern void end_protect_partials PARAMS ((void));
-
-
-/* A list of labels used for exception handlers. */
-extern rtx exception_handler_labels;
+/* Invokes CALLBACK for every exception region in the current function. */
+extern void for_each_eh_region (void (*) (struct eh_region *));
/* Determine if the given INSN can throw an exception. */
-extern bool can_throw_internal PARAMS ((rtx));
-extern bool can_throw_external PARAMS ((rtx));
-
-/* Return nonzero if nothing in this function can throw. */
-extern bool nothrow_function_p PARAMS ((void));
-
-/* After initial rtl generation, call back to finish generating
- exception support code. */
-extern void finish_eh_generation PARAMS ((void));
-
-extern void init_eh PARAMS ((void));
-extern void init_eh_for_function PARAMS ((void));
-
-extern rtx reachable_handlers PARAMS ((rtx));
-extern void maybe_remove_eh_handler PARAMS ((rtx));
-
-extern void convert_from_eh_region_ranges PARAMS ((void));
-extern void convert_to_eh_region_ranges PARAMS ((void));
-extern void find_exception_handler_labels PARAMS ((void));
-extern void output_function_exception_table PARAMS ((void));
-
-extern void expand_builtin_unwind_init PARAMS ((void));
-extern rtx expand_builtin_eh_return_data_regno PARAMS ((tree));
-extern rtx expand_builtin_extract_return_addr PARAMS ((tree));
-extern rtx expand_builtin_frob_return_addr PARAMS ((tree));
-extern rtx expand_builtin_dwarf_fp_regnum PARAMS ((void));
-extern void expand_builtin_eh_return PARAMS ((tree, tree));
-extern void expand_eh_return PARAMS ((void));
-
-extern rtx get_exception_pointer PARAMS ((void));
-
-struct function;
-struct inline_remap;
-extern int duplicate_eh_regions PARAMS ((struct function *,
- struct inline_remap *));
-
-extern void sjlj_emit_function_exit_after PARAMS ((rtx));
-
-
-/* Nonzero to protect cleanup actions with must-not-throw regions. */
-extern tree protect_cleanup_actions;
+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 *gen_eh_region_cleanup (struct eh_region *,
+ struct eh_region *);
+extern struct eh_region *gen_eh_region_try (struct eh_region *);
+extern struct eh_region *gen_eh_region_catch (struct eh_region *, tree);
+extern struct eh_region *gen_eh_region_allowed (struct eh_region *, tree);
+extern struct eh_region *gen_eh_region_must_not_throw (struct eh_region *);
+extern int get_eh_region_number (struct eh_region *);
+extern bool get_eh_region_may_contain_throw (struct eh_region *);
+extern tree get_eh_region_no_tree_label (int);
+extern tree get_eh_region_tree_label (struct eh_region *);
+extern void set_eh_region_tree_label (struct eh_region *, tree);
+
+extern void foreach_reachable_handler (int, bool, bool,
+ void (*) (struct eh_region *, void *),
+ void *);
+
+extern void collect_eh_region_array (void);
+extern void expand_resx_expr (tree);
+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) PARAMS ((tree a, tree 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) PARAMS ((tree));
-
-#ifndef TREE_CODE
-#undef tree
-#endif
-
-#ifndef RTX_CODE
-#undef rtx
-#endif
-
-#ifndef _VARRAY_H_
-#undef varray_type
-#endif
+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. */
-#if !defined (EH_RETURN_DATA_REGNO) \
- || !defined(EH_RETURN_STACKADJ_RTX) \
- || ! (defined(EH_RETURN_HANDLER_RTX) \
- || defined(HAVE_eh_return)) \
- || ! (defined(DWARF2_UNWIND_INFO) \
- || defined(IA64_UNWIND_INFO))
-#define MUST_USE_SJLJ_EXCEPTIONS 1
-#else
-#define MUST_USE_SJLJ_EXCEPTIONS 0
+#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
# endif
# if CONFIG_SJLJ_EXCEPTIONS == 0
# define USING_SJLJ_EXCEPTIONS 0
-# ifndef EH_RETURN_DATA_REGNO
+# if !defined(EH_RETURN_DATA_REGNO)
#error "EH_RETURN_DATA_REGNO required"
# endif
-# ifndef EH_RETURN_STACKADJ_RTX
- #error "EH_RETURN_STACKADJ_RTX required"
+# if ! (defined(TARGET_UNWIND_INFO) || DWARF2_UNWIND_INFO)
+ #error "{DWARF2,TARGET}_UNWIND_INFO required"
# endif
-# if !defined(EH_RETURN_HANDLER_RTX) && !defined(HAVE_eh_return)
+# if !defined(TARGET_UNWIND_INFO) \
+ && !(defined(EH_RETURN_HANDLER_RTX) || defined(HAVE_eh_return))
#error "EH_RETURN_HANDLER_RTX or eh_return required"
# endif
-# if !defined(DWARF2_UNWIND_INFO) && !defined(IA64_UNWIND_INFO)
- #error "{DWARF2,IA64}_UNWIND_INFO required"
+/* 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 struct eh_region *redirect_eh_edge_to_label (struct edge_def *, tree, bool, bool, int);
+extern int get_next_region_sharing_label (int);