/* Exception Handling interface routines.
- Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
+ Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
+ 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 2, 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. */
-
-#if !defined(NULL_RTX) && !defined(rtx)
-typedef struct rtx_def *_except_rtx;
-#define rtx _except_rtx
+along with GCC; see the file COPYING. If not, write to the Free
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
+
+
+struct function;
+
+/* Per-function EH data. Used only in except.c, but GC and others
+ manipulate pointers to the opaque type. */
+struct eh_status;
+
+/* Internal structure describing a region. */
+struct eh_region;
+
+/* 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 *);
+extern void note_current_region_may_contain_throw (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));
+
+/* 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_1 (int, bool);
+extern bool can_throw_internal (rtx);
+extern bool can_throw_external_1 (int, bool);
+extern bool can_throw_external (rtx);
+
+/* Set TREE_NOTHROW and cfun->all_throwers_are_sibcalls. */
+extern unsigned int set_nothrow_function_flags (void);
+
+/* After initial rtl generation, call back to finish generating
+ exception support code. */
+extern void finish_eh_generation (void);
+
+extern void init_eh (void);
+extern void init_eh_for_function (void);
+
+extern rtx reachable_handlers (rtx);
+extern void maybe_remove_eh_handler (rtx);
+
+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 (void);
+
+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 (struct function *);
+extern rtx get_exception_filter (struct function *);
+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_tree_label (struct eh_region *);
+extern void set_eh_region_tree_label (struct eh_region *, tree);
+
+extern void foreach_reachable_handler (int, 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 *);
+extern bool eh_region_outer_p (struct function *, int, int);
+extern int eh_region_outermost (struct function *, int, int);
+
+/* tree-eh.c */
+extern void add_stmt_to_eh_region_fn (struct function *, tree, int);
+extern bool remove_stmt_from_eh_region_fn (struct function *, tree);
+extern int lookup_stmt_eh_region_fn (struct function *, tree);
+extern int lookup_stmt_eh_region (tree);
+extern bool verify_eh_edges (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 tree (*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 1
+# else
+# define MUST_USE_SJLJ_EXCEPTIONS 0
+# endif
#endif
-#ifdef TREE_CODE
-
-/* A stack of labels. CHAIN points to the next entry in the stack. */
-
-struct label_node {
- union {
- rtx rlabel;
- tree tlabel;
- } u;
- struct label_node *chain;
-};
-
-/* An eh_entry is used to describe one exception handling region.
-
- OUTER_CONTEXT is the label used for rethrowing into the outer context.
-
- EXCEPTION_HANDLER_LABEL is the label corresponding to the handler
- for this region.
-
- LABEL_USED indicates whether a CATCH block has already used this
- label or not. New ones are needed for additional catch blocks if
- it has.
-
- FALSE_LABEL is used when either setjmp/longjmp exceptions are in
- use, or old style table exceptions. It contains the label for
- branching to the next runtime type check as handlers are processed.
-
- FINALIZATION is the tree codes for the handler, or is NULL_TREE if
- one hasn't been generated yet, or is integer_zero_node to mark the
- end of a group of try blocks. */
-
-struct eh_entry {
- rtx outer_context;
- rtx exception_handler_label;
- tree finalization;
- int label_used;
- rtx false_label;
- rtx rethrow_label;
- /* If non-zero, this entry is for a handler created when we left an
- exception-region via goto. */
- unsigned goto_entry_p : 1;
-};
+#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
+# ifndef EH_RETURN_DATA_REGNO
+ #error "EH_RETURN_DATA_REGNO required"
+# endif
+# if !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(TARGET_UNWIND_INFO)
+ #error "{DWARF2,TARGET}_UNWIND_INFO required"
+# endif
+# endif
#else
-struct label_node;
-struct eh_entry;
+# define USING_SJLJ_EXCEPTIONS MUST_USE_SJLJ_EXCEPTIONS
#endif
-/* A list of EH_ENTRYs. ENTRY is the entry; CHAIN points to the next
- entry in the list, or is NULL if this is the last entry. */
-
-struct eh_node {
- struct eh_entry *entry;
- struct eh_node *chain;
-};
-
-/* A stack of EH_ENTRYs. TOP is the topmost entry on the stack. TOP is
- NULL if the stack is empty. */
-
-struct eh_stack {
- struct eh_node *top;
-};
-
-/* A queue of EH_ENTRYs. HEAD is the front of the queue; TAIL is the
- end (the latest entry). HEAD and TAIL are NULL if the queue is
- empty. */
-
-struct eh_queue {
- struct eh_node *head;
- struct eh_node *tail;
-};
-
-/* Used to save exception handling status for each function. */
-struct eh_status
+struct throw_stmt_node GTY(())
{
- /* A stack used for keeping track of the currently active exception
- handling region. As each exception region is started, an entry
- describing the region is pushed onto this stack. The current
- region can be found by looking at the top of the stack, and as we
- exit regions, the corresponding entries are popped.
-
- Entries cannot overlap; they can be nested. So there is only one
- entry at most that corresponds to the current instruction, and that
- is the entry on the top of the stack. */
- struct eh_stack x_ehstack;
- /* This stack is used to represent what the current eh region is
- for the catch blocks beings processed */
- struct eh_stack x_catchstack;
- /* A queue used for tracking which exception regions have closed.
- As we exit a region, we enqueue a new entry. The entries are then
- dequeued during expand_leftover_cleanups and
- expand_start_all_catch. */
- struct eh_queue x_ehqueue;
- /* Insns for all of the exception handlers for the current function.
- They are currently emitted by the frontend code. */
- rtx x_catch_clauses;
- /* A random data area for the front end's own use. */
- struct label_node *x_false_label_stack;
- /* Keeps track of the label to resume to should one want to resume
- normal control flow out of a handler (instead of, say, returning to
- the caller of the current function or exiting the program). */
- struct label_node *x_caught_return_label_stack;
- /* A stack (TREE_LIST) of lists of handlers. The TREE_VALUE of each
- node is itself a TREE_CHAINed list of handlers for regions that
- are not yet closed. The TREE_VALUE of each entry contains the
- handler for the corresponding entry on the ehstack. */
- union tree_node *x_protect_list;
- /* The EH context. Nonzero if the function has already
- fetched a pointer to the EH context for exception handling. */
- rtx ehc;
- /* The label generated by expand_builtin_eh_return. */
- rtx x_eh_return_stub_label;
+ tree stmt;
+ int region_nr;
};
-#define ehstack (current_function->eh->x_ehstack)
-#define catchstack (current_function->eh->x_catchstack)
-#define ehqueue (current_function->eh->x_ehqueue)
-#define catch_clauses (current_function->eh->x_catch_clauses)
-#define false_label_stack (current_function->eh->x_false_label_stack)
-#define caught_return_label_stack (current_function->eh->x_caught_return_label_stack)
-#define protect_list (current_function->eh->x_protect_list)
-#define current_function_ehc (current_function->eh->ehc)
-#define eh_return_stub_label (current_function->eh->x_eh_return_stub_label)
-
-#ifdef TREE_CODE
-/* Start an exception handling region. All instructions emitted after
- this point are considered to be part of the region until
- expand_eh_region_end () is invoked. */
-
-extern void expand_eh_region_start PROTO((void));
-
-/* Just like expand_eh_region_start, except if a cleanup action is
- entered on the cleanup chain, the TREE_PURPOSE of the element put
- on the chain is DECL. DECL should be the associated VAR_DECL, if
- any, otherwise it should be NULL_TREE. */
-
-extern void expand_eh_region_start_for_decl PROTO((tree));
-
-/* Start an exception handling region for the given cleanup action.
- All instructions emitted after this point are considered to be part
- of the region until expand_eh_region_end () is invoked. CLEANUP is
- the cleanup action to perform. The return value is true if the
- exception region was optimized away. If that case,
- expand_eh_region_end does not need to be called for this cleanup,
- nor should it be.
-
- This routine notices one particular common case in C++ code
- generation, and optimizes it so as to not need the exception
- region. */
-
-extern int expand_eh_region_start_tree PROTO((tree, tree));
-
-/* End an exception handling region. The information about the region
- is found on the top of ehstack.
-
- HANDLER is either the cleanup for the exception region, or if we're
- marking the end of a try block, HANDLER is integer_zero_node.
-
- HANDLER will be transformed to rtl when expand_leftover_cleanups ()
- is invoked. */
-
-extern void expand_eh_region_end PROTO((tree));
-
-/* Push RLABEL or TLABEL onto LABELSTACK. Only one of RLABEL or TLABEL
- should be set; the other must be NULL. */
-
-extern void push_label_entry PROTO((struct label_node **labelstack, rtx rlabel, tree tlabel));
-
-/* Pop the topmost entry from LABELSTACK and return its value as an
- rtx node. If LABELSTACK is empty, return NULL. */
-
-extern rtx pop_label_entry PROTO((struct label_node **labelstack));
-
-/* Return the topmost entry of LABELSTACK as a tree node, or return
- NULL_TREE if LABELSTACK is empty. */
-
-extern tree top_label_entry PROTO((struct label_node **labelstack));
-
-#endif
-
-/* Test: is exception handling turned on? */
-
-extern int doing_eh PROTO ((int));
-
-/* Toplevel initialization for EH. */
-
-void set_exception_lang_code PROTO((int));
-void set_exception_version_code PROTO((int));
-
-/* A list of handlers asocciated with an exception region. HANDLER_LABEL
- is the the label that control should be transfered to if the data
- in TYPE_INFO matches an exception. a value of NULL_TREE for TYPE_INFO
- means This is a cleanup, and must always be called. A value of
- CATCH_ALL_TYPE works like a cleanup, but a call to the runtime matcher
- is still performed to avoid being caught by a different language
- exception. NEXT is a pointer to the next handler for this region.
- NULL means there are no more. */
-
-typedef struct handler_info
-{
- rtx handler_label;
- int handler_number;
- void *type_info;
- struct handler_info *next;
-} handler_info;
-
-
-/* Add new handler information to an exception range. The first parameter
- specifies the range number (returned from new_eh_entry()). The second
- parameter specifies the handler. By default the handler is inserted at
- the end of the list. A handler list may contain only ONE NULL_TREE
- typeinfo entry. Regardless where it is positioned, a NULL_TREE entry
- is always output as the LAST handler in the exception table for a region. */
-
-void add_new_handler PROTO((int, struct handler_info *));
-
-/* Remove a handler label. The handler label is being deleted, so all
- regions which reference this handler should have it removed from their
- list of possible handlers. Any region which has the final handler
- removed can be deleted. */
-
-void remove_handler PROTO((rtx));
-
-/* Create a new handler structure initialized with the handler label and
- typeinfo fields passed in. */
-
-struct handler_info *get_new_handler PROTO((rtx, void *));
-
-/* Make a duplicate of an exception region by copying all the handlers
- for an exception region. Return the new handler index. */
-
-int duplicate_eh_handlers PROTO((int, int, rtx (*)(rtx)));
-
-/* map symbol refs for rethrow */
-
-rtx rethrow_symbol_map PROTO((rtx, rtx (*)(rtx)));
-
-/* Is the rethrow label for a region used? */
-
-int rethrow_used PROTO((int));
-
-/* Update the rethrow references to reflect rethrows which have been
- optimized away. */
-
-void update_rethrow_references PROTO((void));
-
-/* Get a pointer to the first handler in an exception region's list. */
-
-struct handler_info *get_first_handler PROTO((int));
-
-/* Find all the runtime handlers type matches currently referenced */
-
-int find_all_handler_type_matches PROTO((void ***));
-
-/* The eh_nesting_info structure is used to find a list of valid handlers
- for any arbitrary exception region. When init_eh_nesting_info is called,
- the information is all pre-calculated and entered in this structure.
- REGION_INDEX is a vector over all possible region numbers. Since the
- number of regions is typically much smaller than the range of block
- numbers, this is a sparse vector and the other data structures are
- represented as dense vectors. Indexed with an exception region number, this
- returns the index to use in the other data structures to retreive the
- correct information.
- HANDLERS is an array of vectors which point to handler_info structures.
- when indexed, it gives the list of all possible handlers which can
- be reached by a throw from this exception region.
- NUM_HANDLERS is the equivilent array indicating how many handler
- pointers there are in the HANDLERS vector.
- OUTER_INDEX indicates which index represents the information for the
- outer block. 0 indicates there is no outer context.
- REGION_COUNT is the number of regions. */
-
-typedef struct eh_nesting
-{
- int *region_index;
- handler_info ***handlers;
- int *num_handlers;
- int *outer_index;
- int region_count;
-} eh_nesting_info;
-
-/* Initialize the eh_nesting_info structure. */
-
-eh_nesting_info *init_eh_nesting_info PROTO((void));
-
-/* Get a list of handlers reachable from a an exception region/insn. */
-
-int reachable_handlers PROTO((int, eh_nesting_info *, rtx,
- handler_info ***handlers));
-
-/* Free the eh_nesting_info structure. */
-
-void free_eh_nesting_info PROTO((eh_nesting_info *));
-
-extern void init_eh PROTO((void));
-
-/* Initialization for the per-function EH data. */
-
-extern void init_eh_for_function PROTO((void));
-
-/* Generate an exception label. Use instead of gen_label_rtx */
-
-extern rtx gen_exception_label PROTO((void));
-
-/* Adds an EH table entry for EH entry number N. Called from
- final_scan_insn for NOTE_INSN_EH_REGION_BEG. */
-
-extern void add_eh_table_entry PROTO((int n));
-
-/* Start a catch clause, triggered by runtime value paramter. */
-
-#ifdef TREE_CODE
-extern void start_catch_handler PROTO((tree));
-#endif
-
-/* End an individual catch clause. */
-
-extern void end_catch_handler PROTO((void));
-
-/* Returns a non-zero value if we need to output an exception table. */
-
-extern int exception_table_p PROTO((void));
-
-/* Outputs the exception table if we have one. */
-
-extern void output_exception_table PROTO((void));
-
-/* Given a return address in ADDR, determine the address we should use
- to find the corresponding EH region. */
-
-extern rtx eh_outer_context PROTO((rtx addr));
-
-/* Called at the start of a block of try statements for which there is
- a supplied catch handler. */
-
-extern void expand_start_try_stmts PROTO((void));
-
-/* Called at the start of a block of catch statements. It terminates the
- previous set of try statements. */
-
-extern void expand_start_all_catch PROTO((void));
-
-/* Called at the end of a block of catch statements. */
-
-extern void expand_end_all_catch PROTO((void));
-
-/* Begin a region that will contain entries created with
- add_partial_entry. */
-
-extern void begin_protect_partials PROTO((void));
-
-#ifdef TREE_CODE
-/* 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 PROTO((tree handler));
-#endif
-
-/* End all of the pending exception regions that have handlers added with
- push_protect_entry (). */
-
-extern void end_protect_partials PROTO((void));
-
-/* An internal throw. */
-
-extern void expand_internal_throw PROTO((void));
-
-/* Called from expand_exception_blocks and expand_end_catch_block to
- expand and pending handlers. */
-
-extern void expand_leftover_cleanups PROTO((void));
-
-/* If necessary, emit insns to get EH context for the current
- function. */
-
-extern void emit_eh_context PROTO((void));
-
-/* Builds a list of handler labels and puts them in the global
- variable exception_handler_labels. */
-
-extern void find_exception_handler_labels PROTO((void));
-
-/* Determine if an arbitrary label is an exception label */
-
-extern int is_exception_handler_label PROTO((int));
-
-/* Performs sanity checking on the check_exception_handler_labels
- list. */
-
-extern void check_exception_handler_labels PROTO((void));
-
-/* Keeps track of the label used as the context of a throw to rethrow an
- exception to the outer exception region. */
-
-extern struct label_node *outer_context_label_stack;
-
-/* A list of labels used for exception handlers. It is created by
- find_exception_handler_labels for the optimization passes. */
-
-extern rtx exception_handler_labels;
-
-/* Performs optimizations for exception handling, such as removing
- unnecessary exception regions. Invoked from jump_optimize (). */
-
-extern void exception_optimize PROTO((void));
-
-/* Return EH context (and set it up once per fn). */
-extern rtx get_eh_context PROTO((void));
-
-/* Get the dynamic handler chain. */
-extern rtx get_dynamic_handler_chain PROTO((void));
-
-/* Get the dynamic cleanup chain. */
-extern rtx get_dynamic_cleanup_chain PROTO((void));
-
-/* Throw an exception. */
-
-extern void emit_throw PROTO((void));
-
-/* One to use setjmp/longjmp method of generating code. */
-
-extern int exceptions_via_longjmp;
-
-/* One to enable asynchronous exception support. */
-
-extern int asynchronous_exceptions;
-
-/* One to protect cleanup actions with a handler that calls
- __terminate, zero otherwise. */
-
-extern int protect_cleanup_actions_with_terminate;
-
-#ifdef TREE_CODE
-extern tree protect_with_terminate PROTO((tree));
-#endif
-
-extern void expand_fixup_region_start PROTO((void));
-#ifdef TREE_CODE
-extern void expand_fixup_region_end PROTO((tree));
-#endif
-
-/* Various hooks for the DWARF 2 __throw routine. */
-
-void expand_builtin_unwind_init PROTO((void));
-rtx expand_builtin_dwarf_fp_regnum PROTO((void));
-#ifdef TREE_CODE
-rtx expand_builtin_frob_return_addr PROTO((tree));
-rtx expand_builtin_extract_return_addr PROTO((tree));
-void expand_builtin_init_dwarf_reg_sizes PROTO((tree));
-void expand_builtin_eh_return PROTO((tree, tree, tree));
-#endif
-void expand_eh_return PROTO((void));
-
-
-/* Checking whether 2 instructions are within the same exception region. */
-
-int in_same_eh_region PROTO((rtx, rtx));
-void free_insn_eh_region PROTO((void));
-void init_insn_eh_region PROTO((rtx, int));
+extern struct htab *get_eh_throw_stmt_table (struct function *);
+extern void set_eh_throw_stmt_table (struct function *, struct htab *);
-#ifdef rtx
-#undef rtx
+#ifdef ENABLE_CHECKING
+extern void verify_eh_throw_table_statements (void);
#endif
OSDN Git Service
