/* Exception Handling interface routines. Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc. Contributed by Mike Stump <mrs@cygnus.com>. This file is part of GNU CC. 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. 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. 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 #endif /* The label generated by expand_builtin_eh_return. */ extern rtx eh_return_stub_label; #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; }; /* 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; }; /* 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)); /* A set of insns for the catch clauses in the current function. They will be emitted at the end of the current function. */ extern rtx catch_clauses; #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)); /* Return the region number a this is the rethrow label for. */ int eh_region_from_symbol PROTO((rtx)); /* 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 ***)); 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)); #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)); /* A stack used to keep track of the label used to resume normal program flow out of the current exception handler region. */ extern struct label_node *caught_return_label_stack; /* 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 random area used for purposes elsewhere. */ extern struct label_node *false_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)); rtx expand_builtin_dwarf_reg_size PROTO((tree, rtx)); 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)); #ifdef rtx #undef rtx #endif