/* Exception Handling interface routines.
- Copyright (C) 1996 Free Software Foundation, Inc.
+ Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
Contributed by Mike Stump <mrs@cygnus.com>.
This file is part of GNU CC.
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
-
-#ifndef GET_CODE
-#define rtx int *
+#if !defined(NULL_RTX) && !defined(rtx)
+typedef struct rtx_def *_except_rtx;
+#define rtx _except_rtx
#endif
#ifdef TREE_CODE
+/* A stack of labels. CHAIN points to the next entry in the stack. */
+
struct label_node {
union {
rtx rlabel;
struct label_node *chain;
};
-/* A entry for the exception handling stack EHSTACK or the exception
- handling queue EHQUEUE. */
+/* 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 start_label;
- rtx end_label;
+ 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;
};
+#else
+struct label_node;
+struct eh_entry;
+#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;
+ struct eh_queue *next;
};
+/* Used to save exception handling status for each function. */
+struct eh_status
+{
+ /* 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;
+ /* End of exception handler insn sequence. */
+ rtx x_catch_clauses_last;
+ /* 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;
+};
+
+#define ehstack (cfun->eh->x_ehstack)
+#define catchstack (cfun->eh->x_catchstack)
+#define ehqueue (cfun->eh->x_ehqueue)
+#define catch_clauses (cfun->eh->x_catch_clauses)
+#define catch_clauses_last (cfun->eh->x_catch_clauses_last)
+#define false_label_stack (cfun->eh->x_false_label_stack)
+#define caught_return_label_stack (cfun->eh->x_caught_return_label_stack)
+#define protect_list (cfun->eh->x_protect_list)
+#define current_function_ehc (cfun->eh->ehc)
+#define eh_return_stub_label (cfun->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 PARAMS ((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 PARAMS ((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 PARAMS ((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 PARAMS ((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 PARAMS ((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 PARAMS ((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 PARAMS ((struct label_node **labelstack));
+
+#endif
+
+/* Test: is exception handling turned on? */
+
+extern int doing_eh PARAMS ((int));
+
+/* Toplevel initialization for EH. */
+
+void set_exception_lang_code PARAMS ((int));
+void set_exception_version_code PARAMS ((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 PARAMS ((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 PARAMS ((rtx));
+
+/* Create a new handler structure initialized with the handler label and
+ typeinfo fields passed in. */
+
+struct handler_info *get_new_handler PARAMS ((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 PARAMS ((int, int, rtx (*)(rtx)));
+
+/* map symbol refs for rethrow */
+
+rtx rethrow_symbol_map PARAMS ((rtx, rtx (*)(rtx)));
+
+/* Is the rethrow label for a region used? */
+
+int rethrow_used PARAMS ((int));
+
+/* Update the rethrow references to reflect rethrows which have been
+ optimized away. */
+
+void update_rethrow_references PARAMS ((void));
+
+/* Get a pointer to the first handler in an exception region's list. */
+
+struct handler_info *get_first_handler PARAMS ((int));
+
+/* Find all the runtime handlers type matches currently referenced */
+
+int find_all_handler_type_matches PARAMS ((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 PARAMS ((void));
+
+/* Get a list of handlers reachable from a an exception region/insn. */
+
+int reachable_handlers PARAMS ((int, eh_nesting_info *, rtx,
+ handler_info ***handlers));
+
+/* Free the eh_nesting_info structure. */
+
+void free_eh_nesting_info PARAMS ((eh_nesting_info *));
+
+extern void init_eh PARAMS ((void));
+
+/* Initialization for the per-function EH data. */
+
+extern void init_eh_for_function PARAMS ((void));
-extern void push_label_entry PROTO((struct label_node **labelstack, rtx rlabel, tree tlabel));
-extern rtx pop_label_entry PROTO((struct label_node **labelstack));
-extern tree top_label_entry PROTO((struct label_node **labelstack));
+/* Generate an exception label. Use instead of gen_label_rtx */
-extern struct eh_stack ehstack;
-extern struct eh_queue ehqueue;
-extern rtx catch_clauses;
-extern tree protect_list;
+extern rtx gen_exception_label PARAMS ((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 PARAMS ((int n));
+
+/* Start a catch clause, triggered by runtime value paramter. */
+
+#ifdef TREE_CODE
+extern void start_catch_handler PARAMS ((tree));
+#endif
+
+/* End an individual catch clause. */
+
+extern void end_catch_handler PARAMS ((void));
+
+/* Returns a non-zero value if we need to output an exception table. */
+
+extern int exception_table_p PARAMS ((void));
+
+/* Outputs the exception table if we have one. */
+
+extern void output_exception_table PARAMS ((void));
+extern void output_exception_table_data PARAMS ((void));
+
+/* Free the exception table. */
+
+extern void free_exception_table PARAMS((void));
+
+/* Used by the ia64 unwind format to output data for an individual
+ function. */
+
+extern void output_function_exception_table PARAMS((void));
+
+/* Given a return address in ADDR, determine the address we should use
+ to find the corresponding EH region. */
+
+extern rtx eh_outer_context PARAMS ((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 PARAMS ((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 PARAMS ((void));
+
+/* Called at the end of a block of catch statements. */
+
+extern void expand_end_all_catch PARAMS ((void));
+
+/* Begin a region that will contain entries created with
+ add_partial_entry. */
+
+extern void begin_protect_partials PARAMS ((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 PARAMS ((tree handler));
#endif
-struct function;
+/* End all of the pending exception regions that have handlers added with
+ push_protect_entry (). */
+
+extern void end_protect_partials PARAMS ((void));
+
+/* An internal throw. */
+
+extern void expand_internal_throw PARAMS ((void));
+
+/* Called from expand_exception_blocks and expand_end_catch_block to
+ expand and pending handlers. */
+
+extern void expand_leftover_cleanups PARAMS ((void));
+
+/* If necessary, emit insns to get EH context for the current
+ function. */
+
+extern void emit_eh_context PARAMS ((void));
+
+/* Builds a list of handler labels and puts them in the global
+ variable exception_handler_labels. */
-extern void init_eh PROTO((void));
-extern void init_eh_for_function PROTO((void));
-extern void save_eh_status PROTO((struct function *p));
-extern void restore_eh_status PROTO((struct function *p));
-extern void add_eh_table_entry PROTO((int));
-extern int exception_table_p PROTO((void));
-extern void output_exception_table PROTO((void));
-extern rtx eh_outer_context PROTO((rtx));
-extern void emit_unwinder PROTO((void));
-extern void end_eh_unwinder PROTO((void));
-extern void find_handler_labels PROTO((void));
-extern void check_handler_labels PROTO((void));
+extern void find_exception_handler_labels PARAMS ((void));
+/* Determine if an arbitrary label is an exception label */
-extern struct label_node *caught_return_label_stack;
-extern struct label_node *false_label_stack;
+extern int is_exception_handler_label PARAMS ((int));
+
+/* Performs sanity checking on the check_exception_handler_labels
+ list. */
+
+extern void check_exception_handler_labels PARAMS ((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;
-/* The rtx for the saved PC value. */
+/* Determine if the given INSN can throw an exception. */
+
+extern int can_throw PARAMS ((rtx));
+
+/* Return nonzero if nothing in this function can throw. */
+
+extern int nothrow_function_p PARAMS ((void));
+
+/* Performs optimizations for exception handling, such as removing
+ unnecessary exception regions. Invoked from jump_optimize (). */
+
+extern void exception_optimize PARAMS ((void));
+
+/* Return EH context (and set it up once per fn). */
+extern rtx get_eh_context PARAMS ((void));
+
+/* Get the dynamic handler chain. */
+extern rtx get_dynamic_handler_chain PARAMS ((void));
+
+/* Get the dynamic cleanup chain. */
+extern rtx get_dynamic_cleanup_chain PARAMS ((void));
+
+/* Throw an exception. */
+
+extern void emit_throw PARAMS ((void));
+
+/* Save away the current ehqueue. */
+extern void push_ehqueue PARAMS ((void));
+
+/* Restore a previously pushed ehqueue. */
+extern void pop_ehqueue PARAMS ((void));
+
+/* One to use setjmp/longjmp method of generating code. */
-extern rtx eh_saved_pc_rtx;
+extern int exceptions_via_longjmp;
-extern void exception_optimize PROTO((void));
+/* 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 PARAMS ((tree));
+#endif
+
+extern void expand_fixup_region_start PARAMS ((void));
+#ifdef TREE_CODE
+extern void expand_fixup_region_end PARAMS ((tree));
+#endif
+
+/* Various hooks for the DWARF 2 __throw routine. */
+
+void expand_builtin_unwind_init PARAMS ((void));
+rtx expand_builtin_dwarf_fp_regnum PARAMS ((void));
+#ifdef TREE_CODE
+rtx expand_builtin_frob_return_addr PARAMS ((tree));
+rtx expand_builtin_extract_return_addr PARAMS ((tree));
+void expand_builtin_init_dwarf_reg_sizes PARAMS ((tree));
+void expand_builtin_eh_return PARAMS ((tree, tree, tree));
+#endif
+void expand_eh_return PARAMS ((void));
+
+
+/* Checking whether 2 instructions are within the same exception region. */
+
+int in_same_eh_region PARAMS ((rtx, rtx));
+void free_insn_eh_region PARAMS ((void));
+void init_insn_eh_region PARAMS ((rtx, int));
+
+#ifdef rtx
+#undef rtx
+#endif