/* Exception Handling interface routines. Copyright (C) 1996 Free Software Foundation, Inc. Contributed by Mike Stump . 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. */ #ifndef GET_CODE #define rtx int * #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. START_LABEL is the label corresponding to the start of the region. END_LABEL is the label corresponding to the end of the region. EXCEPTION_HANDLER_LABEL is the label corresponding to the handler for this region. 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 exception_handler_label; tree finalization; }; /* 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; }; extern void expand_eh_region_start PROTO((void)); 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)); /* The stack used to keep track of the exception region corresponding to the current instruction. */ extern struct eh_stack ehstack; /* A queue used to track closed exception regions whose handlers have not been emitted yet. */ extern struct eh_queue ehqueue; /* 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 struct function; /* Toplevel initialization for EH. */ extern void init_eh PROTO((void)); /* Initialization for the per-function EH data. */ extern void init_eh_for_function PROTO((void)); /* Saves the current per-function EH data into P. */ extern void save_eh_status PROTO((struct function *p)); /* Restores the per-function EH data from P. */ extern void restore_eh_status PROTO((struct function *p)); /* 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)); /* 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 with a direct CONTEXT we want to throw from. CONTEXT must be a label. */ extern void expand_internal_throw PROTO((rtx context)); /* 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 for the start of per-function unwinder for the current function. */ extern void emit_unwinder PROTO((void)); /* If necessary, emit insns for the end of the per-function unwinder for the current function. */ extern void end_eh_unwinder 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)); /* 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; /* 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; /* The rtx for the saved PC value. */ extern rtx eh_saved_pc_rtx; /* Performs optimizations for exception handling, such as removing unnecessary exception regions. Invoked from jump_optimize (). */ extern void exception_optimize PROTO((void));