| /* 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 |