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/* Exception Handling interface routines.
Copyright (C) 1996, 1997 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. */
#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.
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.
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;
};
/* 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. */
extern void init_eh PROTO((void));
/* Initialization for the per-function EH data. */
extern void init_eh_for_function 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));
/* 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));
/* 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;
/* 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
/* Various hooks for the DWARF 2 __throw routine. */
void expand_builtin_unwind_init PROTO((void));
rtx expand_builtin_dwarf_fp_regnum PROTO((void));
rtx expand_builtin_eh_stub PROTO((void));
#ifdef TREE_CODE
rtx expand_builtin_frob_return_addr PROTO((tree));
rtx expand_builtin_extract_return_addr PROTO((tree));
void expand_builtin_set_return_addr_reg PROTO((tree));
void expand_builtin_set_eh_regs PROTO((tree, tree));
rtx expand_builtin_dwarf_reg_size PROTO((tree, rtx));
#endif
/* 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));
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