forked from illumos/gcc
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except.c
3426 lines (2884 loc) · 92.9 KB
/
except.c
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/* Implements exception handling.
Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
Contributed by Mike Stump <mrs@cygnus.com>.
This file is part of GCC.
GCC 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 3, or (at your option) any later
version.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* An exception is an event that can be "thrown" from within a
function. This event can then be "caught" by the callers of
the function.
The representation of exceptions changes several times during
the compilation process:
In the beginning, in the front end, we have the GENERIC trees
TRY_CATCH_EXPR, TRY_FINALLY_EXPR, WITH_CLEANUP_EXPR,
CLEANUP_POINT_EXPR, CATCH_EXPR, and EH_FILTER_EXPR.
During initial gimplification (gimplify.c) these are lowered
to the GIMPLE_TRY, GIMPLE_CATCH, and GIMPLE_EH_FILTER nodes.
The WITH_CLEANUP_EXPR and CLEANUP_POINT_EXPR nodes are converted
into GIMPLE_TRY_FINALLY nodes; the others are a more direct 1-1
conversion.
During pass_lower_eh (tree-eh.c) we record the nested structure
of the TRY nodes in EH_REGION nodes in CFUN->EH->REGION_TREE.
We expand the eh_protect_cleanup_actions langhook into MUST_NOT_THROW
regions at this time. We can then flatten the statements within
the TRY nodes to straight-line code. Statements that had been within
TRY nodes that can throw are recorded within CFUN->EH->THROW_STMT_TABLE,
so that we may remember what action is supposed to be taken if
a given statement does throw. During this lowering process,
we create an EH_LANDING_PAD node for each EH_REGION that has
some code within the function that needs to be executed if a
throw does happen. We also create RESX statements that are
used to transfer control from an inner EH_REGION to an outer
EH_REGION. We also create EH_DISPATCH statements as placeholders
for a runtime type comparison that should be made in order to
select the action to perform among different CATCH and EH_FILTER
regions.
During pass_lower_eh_dispatch (tree-eh.c), which is run after
all inlining is complete, we are able to run assign_filter_values,
which allows us to map the set of types manipulated by all of the
CATCH and EH_FILTER regions to a set of integers. This set of integers
will be how the exception runtime communicates with the code generated
within the function. We then expand the GIMPLE_EH_DISPATCH statements
to a switch or conditional branches that use the argument provided by
the runtime (__builtin_eh_filter) and the set of integers we computed
in assign_filter_values.
During pass_lower_resx (tree-eh.c), which is run near the end
of optimization, we expand RESX statements. If the eh region
that is outer to the RESX statement is a MUST_NOT_THROW, then
the RESX expands to some form of abort statement. If the eh
region that is outer to the RESX statement is within the current
function, then the RESX expands to a bookkeeping call
(__builtin_eh_copy_values) and a goto. Otherwise, the next
handler for the exception must be within a function somewhere
up the call chain, so we call back into the exception runtime
(__builtin_unwind_resume).
During pass_expand (cfgexpand.c), we generate REG_EH_REGION notes
that create an rtl to eh_region mapping that corresponds to the
gimple to eh_region mapping that had been recorded in the
THROW_STMT_TABLE.
During pass_rtl_eh (except.c), we generate the real landing pads
to which the runtime will actually transfer control. These new
landing pads perform whatever bookkeeping is needed by the target
backend in order to resume execution within the current function.
Each of these new landing pads falls through into the post_landing_pad
label which had been used within the CFG up to this point. All
exception edges within the CFG are redirected to the new landing pads.
If the target uses setjmp to implement exceptions, the various extra
calls into the runtime to register and unregister the current stack
frame are emitted at this time.
During pass_convert_to_eh_region_ranges (except.c), we transform
the REG_EH_REGION notes attached to individual insns into
non-overlapping ranges of insns bounded by NOTE_INSN_EH_REGION_BEG
and NOTE_INSN_EH_REGION_END. Each insn within such ranges has the
same associated action within the exception region tree, meaning
that (1) the exception is caught by the same landing pad within the
current function, (2) the exception is blocked by the runtime with
a MUST_NOT_THROW region, or (3) the exception is not handled at all
within the current function.
Finally, during assembly generation, we call
output_function_exception_table (except.c) to emit the tables with
which the exception runtime can determine if a given stack frame
handles a given exception, and if so what filter value to provide
to the function when the non-local control transfer is effected.
If the target uses dwarf2 unwinding to implement exceptions, then
output_call_frame_info (dwarf2out.c) emits the required unwind data. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "tree.h"
#include "flags.h"
#include "function.h"
#include "expr.h"
#include "libfuncs.h"
#include "insn-config.h"
#include "except.h"
#include "integrate.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "output.h"
#include "dwarf2asm.h"
#include "dwarf2out.h"
#include "dwarf2.h"
#include "toplev.h"
#include "hashtab.h"
#include "intl.h"
#include "ggc.h"
#include "tm_p.h"
#include "target.h"
#include "langhooks.h"
#include "cgraph.h"
#include "diagnostic.h"
#include "tree-pretty-print.h"
#include "tree-pass.h"
#include "timevar.h"
#include "tree-flow.h"
/* Provide defaults for stuff that may not be defined when using
sjlj exceptions. */
#ifndef EH_RETURN_DATA_REGNO
#define EH_RETURN_DATA_REGNO(N) INVALID_REGNUM
#endif
static GTY(()) int call_site_base;
static GTY ((param_is (union tree_node)))
htab_t type_to_runtime_map;
/* Describe the SjLj_Function_Context structure. */
static GTY(()) tree sjlj_fc_type_node;
static int sjlj_fc_call_site_ofs;
static int sjlj_fc_data_ofs;
static int sjlj_fc_personality_ofs;
static int sjlj_fc_lsda_ofs;
static int sjlj_fc_jbuf_ofs;
struct GTY(()) call_site_record_d
{
rtx landing_pad;
int action;
};
static bool get_eh_region_and_lp_from_rtx (const_rtx, eh_region *,
eh_landing_pad *);
static int t2r_eq (const void *, const void *);
static hashval_t t2r_hash (const void *);
static int ttypes_filter_eq (const void *, const void *);
static hashval_t ttypes_filter_hash (const void *);
static int ehspec_filter_eq (const void *, const void *);
static hashval_t ehspec_filter_hash (const void *);
static int add_ttypes_entry (htab_t, tree);
static int add_ehspec_entry (htab_t, htab_t, tree);
static void dw2_build_landing_pads (void);
static int action_record_eq (const void *, const void *);
static hashval_t action_record_hash (const void *);
static int add_action_record (htab_t, int, int);
static int collect_one_action_chain (htab_t, eh_region);
static int add_call_site (rtx, int, int);
static void push_uleb128 (VEC (uchar, gc) **, unsigned int);
static void push_sleb128 (VEC (uchar, gc) **, int);
#ifndef HAVE_AS_LEB128
static int dw2_size_of_call_site_table (int);
static int sjlj_size_of_call_site_table (void);
#endif
static void dw2_output_call_site_table (int, int);
static void sjlj_output_call_site_table (void);
void
init_eh (void)
{
if (! flag_exceptions)
return;
type_to_runtime_map = htab_create_ggc (31, t2r_hash, t2r_eq, NULL);
/* Create the SjLj_Function_Context structure. This should match
the definition in unwind-sjlj.c. */
if (targetm.except_unwind_info (&global_options) == UI_SJLJ)
{
tree f_jbuf, f_per, f_lsda, f_prev, f_cs, f_data, tmp;
sjlj_fc_type_node = lang_hooks.types.make_type (RECORD_TYPE);
f_prev = build_decl (BUILTINS_LOCATION,
FIELD_DECL, get_identifier ("__prev"),
build_pointer_type (sjlj_fc_type_node));
DECL_FIELD_CONTEXT (f_prev) = sjlj_fc_type_node;
f_cs = build_decl (BUILTINS_LOCATION,
FIELD_DECL, get_identifier ("__call_site"),
integer_type_node);
DECL_FIELD_CONTEXT (f_cs) = sjlj_fc_type_node;
tmp = build_index_type (build_int_cst (NULL_TREE, 4 - 1));
tmp = build_array_type (lang_hooks.types.type_for_mode
(targetm.unwind_word_mode (), 1),
tmp);
f_data = build_decl (BUILTINS_LOCATION,
FIELD_DECL, get_identifier ("__data"), tmp);
DECL_FIELD_CONTEXT (f_data) = sjlj_fc_type_node;
f_per = build_decl (BUILTINS_LOCATION,
FIELD_DECL, get_identifier ("__personality"),
ptr_type_node);
DECL_FIELD_CONTEXT (f_per) = sjlj_fc_type_node;
f_lsda = build_decl (BUILTINS_LOCATION,
FIELD_DECL, get_identifier ("__lsda"),
ptr_type_node);
DECL_FIELD_CONTEXT (f_lsda) = sjlj_fc_type_node;
#ifdef DONT_USE_BUILTIN_SETJMP
#ifdef JMP_BUF_SIZE
tmp = build_int_cst (NULL_TREE, JMP_BUF_SIZE - 1);
#else
/* Should be large enough for most systems, if it is not,
JMP_BUF_SIZE should be defined with the proper value. It will
also tend to be larger than necessary for most systems, a more
optimal port will define JMP_BUF_SIZE. */
tmp = build_int_cst (NULL_TREE, FIRST_PSEUDO_REGISTER + 2 - 1);
#endif
#else
/* builtin_setjmp takes a pointer to 5 words. */
tmp = build_int_cst (NULL_TREE, 5 * BITS_PER_WORD / POINTER_SIZE - 1);
#endif
tmp = build_index_type (tmp);
tmp = build_array_type (ptr_type_node, tmp);
f_jbuf = build_decl (BUILTINS_LOCATION,
FIELD_DECL, get_identifier ("__jbuf"), tmp);
#ifdef DONT_USE_BUILTIN_SETJMP
/* We don't know what the alignment requirements of the
runtime's jmp_buf has. Overestimate. */
DECL_ALIGN (f_jbuf) = BIGGEST_ALIGNMENT;
DECL_USER_ALIGN (f_jbuf) = 1;
#endif
DECL_FIELD_CONTEXT (f_jbuf) = sjlj_fc_type_node;
TYPE_FIELDS (sjlj_fc_type_node) = f_prev;
TREE_CHAIN (f_prev) = f_cs;
TREE_CHAIN (f_cs) = f_data;
TREE_CHAIN (f_data) = f_per;
TREE_CHAIN (f_per) = f_lsda;
TREE_CHAIN (f_lsda) = f_jbuf;
layout_type (sjlj_fc_type_node);
/* Cache the interesting field offsets so that we have
easy access from rtl. */
sjlj_fc_call_site_ofs
= (tree_low_cst (DECL_FIELD_OFFSET (f_cs), 1)
+ tree_low_cst (DECL_FIELD_BIT_OFFSET (f_cs), 1) / BITS_PER_UNIT);
sjlj_fc_data_ofs
= (tree_low_cst (DECL_FIELD_OFFSET (f_data), 1)
+ tree_low_cst (DECL_FIELD_BIT_OFFSET (f_data), 1) / BITS_PER_UNIT);
sjlj_fc_personality_ofs
= (tree_low_cst (DECL_FIELD_OFFSET (f_per), 1)
+ tree_low_cst (DECL_FIELD_BIT_OFFSET (f_per), 1) / BITS_PER_UNIT);
sjlj_fc_lsda_ofs
= (tree_low_cst (DECL_FIELD_OFFSET (f_lsda), 1)
+ tree_low_cst (DECL_FIELD_BIT_OFFSET (f_lsda), 1) / BITS_PER_UNIT);
sjlj_fc_jbuf_ofs
= (tree_low_cst (DECL_FIELD_OFFSET (f_jbuf), 1)
+ tree_low_cst (DECL_FIELD_BIT_OFFSET (f_jbuf), 1) / BITS_PER_UNIT);
}
}
void
init_eh_for_function (void)
{
cfun->eh = ggc_alloc_cleared_eh_status ();
/* Make sure zero'th entries are used. */
VEC_safe_push (eh_region, gc, cfun->eh->region_array, NULL);
VEC_safe_push (eh_landing_pad, gc, cfun->eh->lp_array, NULL);
}
/* Routines to generate the exception tree somewhat directly.
These are used from tree-eh.c when processing exception related
nodes during tree optimization. */
static eh_region
gen_eh_region (enum eh_region_type type, eh_region outer)
{
eh_region new_eh;
/* Insert a new blank region as a leaf in the tree. */
new_eh = ggc_alloc_cleared_eh_region_d ();
new_eh->type = type;
new_eh->outer = outer;
if (outer)
{
new_eh->next_peer = outer->inner;
outer->inner = new_eh;
}
else
{
new_eh->next_peer = cfun->eh->region_tree;
cfun->eh->region_tree = new_eh;
}
new_eh->index = VEC_length (eh_region, cfun->eh->region_array);
VEC_safe_push (eh_region, gc, cfun->eh->region_array, new_eh);
/* Copy the language's notion of whether to use __cxa_end_cleanup. */
if (targetm.arm_eabi_unwinder && lang_hooks.eh_use_cxa_end_cleanup)
new_eh->use_cxa_end_cleanup = true;
return new_eh;
}
eh_region
gen_eh_region_cleanup (eh_region outer)
{
return gen_eh_region (ERT_CLEANUP, outer);
}
eh_region
gen_eh_region_try (eh_region outer)
{
return gen_eh_region (ERT_TRY, outer);
}
eh_catch
gen_eh_region_catch (eh_region t, tree type_or_list)
{
eh_catch c, l;
tree type_list, type_node;
gcc_assert (t->type == ERT_TRY);
/* Ensure to always end up with a type list to normalize further
processing, then register each type against the runtime types map. */
type_list = type_or_list;
if (type_or_list)
{
if (TREE_CODE (type_or_list) != TREE_LIST)
type_list = tree_cons (NULL_TREE, type_or_list, NULL_TREE);
type_node = type_list;
for (; type_node; type_node = TREE_CHAIN (type_node))
add_type_for_runtime (TREE_VALUE (type_node));
}
c = ggc_alloc_cleared_eh_catch_d ();
c->type_list = type_list;
l = t->u.eh_try.last_catch;
c->prev_catch = l;
if (l)
l->next_catch = c;
else
t->u.eh_try.first_catch = c;
t->u.eh_try.last_catch = c;
return c;
}
eh_region
gen_eh_region_allowed (eh_region outer, tree allowed)
{
eh_region region = gen_eh_region (ERT_ALLOWED_EXCEPTIONS, outer);
region->u.allowed.type_list = allowed;
for (; allowed ; allowed = TREE_CHAIN (allowed))
add_type_for_runtime (TREE_VALUE (allowed));
return region;
}
eh_region
gen_eh_region_must_not_throw (eh_region outer)
{
return gen_eh_region (ERT_MUST_NOT_THROW, outer);
}
eh_landing_pad
gen_eh_landing_pad (eh_region region)
{
eh_landing_pad lp = ggc_alloc_cleared_eh_landing_pad_d ();
lp->next_lp = region->landing_pads;
lp->region = region;
lp->index = VEC_length (eh_landing_pad, cfun->eh->lp_array);
region->landing_pads = lp;
VEC_safe_push (eh_landing_pad, gc, cfun->eh->lp_array, lp);
return lp;
}
eh_region
get_eh_region_from_number_fn (struct function *ifun, int i)
{
return VEC_index (eh_region, ifun->eh->region_array, i);
}
eh_region
get_eh_region_from_number (int i)
{
return get_eh_region_from_number_fn (cfun, i);
}
eh_landing_pad
get_eh_landing_pad_from_number_fn (struct function *ifun, int i)
{
return VEC_index (eh_landing_pad, ifun->eh->lp_array, i);
}
eh_landing_pad
get_eh_landing_pad_from_number (int i)
{
return get_eh_landing_pad_from_number_fn (cfun, i);
}
eh_region
get_eh_region_from_lp_number_fn (struct function *ifun, int i)
{
if (i < 0)
return VEC_index (eh_region, ifun->eh->region_array, -i);
else if (i == 0)
return NULL;
else
{
eh_landing_pad lp;
lp = VEC_index (eh_landing_pad, ifun->eh->lp_array, i);
return lp->region;
}
}
eh_region
get_eh_region_from_lp_number (int i)
{
return get_eh_region_from_lp_number_fn (cfun, i);
}
/* Returns true if the current function has exception handling regions. */
bool
current_function_has_exception_handlers (void)
{
return cfun->eh->region_tree != NULL;
}
/* A subroutine of duplicate_eh_regions. Copy the eh_region tree at OLD.
Root it at OUTER, and apply LP_OFFSET to the lp numbers. */
struct duplicate_eh_regions_data
{
duplicate_eh_regions_map label_map;
void *label_map_data;
struct pointer_map_t *eh_map;
};
static void
duplicate_eh_regions_1 (struct duplicate_eh_regions_data *data,
eh_region old_r, eh_region outer)
{
eh_landing_pad old_lp, new_lp;
eh_region new_r;
void **slot;
new_r = gen_eh_region (old_r->type, outer);
slot = pointer_map_insert (data->eh_map, (void *)old_r);
gcc_assert (*slot == NULL);
*slot = (void *)new_r;
switch (old_r->type)
{
case ERT_CLEANUP:
break;
case ERT_TRY:
{
eh_catch oc, nc;
for (oc = old_r->u.eh_try.first_catch; oc ; oc = oc->next_catch)
{
/* We should be doing all our region duplication before and
during inlining, which is before filter lists are created. */
gcc_assert (oc->filter_list == NULL);
nc = gen_eh_region_catch (new_r, oc->type_list);
nc->label = data->label_map (oc->label, data->label_map_data);
}
}
break;
case ERT_ALLOWED_EXCEPTIONS:
new_r->u.allowed.type_list = old_r->u.allowed.type_list;
if (old_r->u.allowed.label)
new_r->u.allowed.label
= data->label_map (old_r->u.allowed.label, data->label_map_data);
else
new_r->u.allowed.label = NULL_TREE;
break;
case ERT_MUST_NOT_THROW:
new_r->u.must_not_throw = old_r->u.must_not_throw;
break;
}
for (old_lp = old_r->landing_pads; old_lp ; old_lp = old_lp->next_lp)
{
/* Don't bother copying unused landing pads. */
if (old_lp->post_landing_pad == NULL)
continue;
new_lp = gen_eh_landing_pad (new_r);
slot = pointer_map_insert (data->eh_map, (void *)old_lp);
gcc_assert (*slot == NULL);
*slot = (void *)new_lp;
new_lp->post_landing_pad
= data->label_map (old_lp->post_landing_pad, data->label_map_data);
EH_LANDING_PAD_NR (new_lp->post_landing_pad) = new_lp->index;
}
/* Make sure to preserve the original use of __cxa_end_cleanup. */
new_r->use_cxa_end_cleanup = old_r->use_cxa_end_cleanup;
for (old_r = old_r->inner; old_r ; old_r = old_r->next_peer)
duplicate_eh_regions_1 (data, old_r, new_r);
}
/* Duplicate the EH regions from IFUN rooted at COPY_REGION into
the current function and root the tree below OUTER_REGION.
The special case of COPY_REGION of NULL means all regions.
Remap labels using MAP/MAP_DATA callback. Return a pointer map
that allows the caller to remap uses of both EH regions and
EH landing pads. */
struct pointer_map_t *
duplicate_eh_regions (struct function *ifun,
eh_region copy_region, int outer_lp,
duplicate_eh_regions_map map, void *map_data)
{
struct duplicate_eh_regions_data data;
eh_region outer_region;
#ifdef ENABLE_CHECKING
verify_eh_tree (ifun);
#endif
data.label_map = map;
data.label_map_data = map_data;
data.eh_map = pointer_map_create ();
outer_region = get_eh_region_from_lp_number (outer_lp);
/* Copy all the regions in the subtree. */
if (copy_region)
duplicate_eh_regions_1 (&data, copy_region, outer_region);
else
{
eh_region r;
for (r = ifun->eh->region_tree; r ; r = r->next_peer)
duplicate_eh_regions_1 (&data, r, outer_region);
}
#ifdef ENABLE_CHECKING
verify_eh_tree (cfun);
#endif
return data.eh_map;
}
/* Return the region that is outer to both REGION_A and REGION_B in IFUN. */
eh_region
eh_region_outermost (struct function *ifun, eh_region region_a,
eh_region region_b)
{
sbitmap b_outer;
gcc_assert (ifun->eh->region_array);
gcc_assert (ifun->eh->region_tree);
b_outer = sbitmap_alloc (VEC_length (eh_region, ifun->eh->region_array));
sbitmap_zero (b_outer);
do
{
SET_BIT (b_outer, region_b->index);
region_b = region_b->outer;
}
while (region_b);
do
{
if (TEST_BIT (b_outer, region_a->index))
break;
region_a = region_a->outer;
}
while (region_a);
sbitmap_free (b_outer);
return region_a;
}
static int
t2r_eq (const void *pentry, const void *pdata)
{
const_tree const entry = (const_tree) pentry;
const_tree const data = (const_tree) pdata;
return TREE_PURPOSE (entry) == data;
}
static hashval_t
t2r_hash (const void *pentry)
{
const_tree const entry = (const_tree) pentry;
return TREE_HASH (TREE_PURPOSE (entry));
}
void
add_type_for_runtime (tree type)
{
tree *slot;
/* If TYPE is NOP_EXPR, it means that it already is a runtime type. */
if (TREE_CODE (type) == NOP_EXPR)
return;
slot = (tree *) htab_find_slot_with_hash (type_to_runtime_map, type,
TREE_HASH (type), INSERT);
if (*slot == NULL)
{
tree runtime = lang_hooks.eh_runtime_type (type);
*slot = tree_cons (type, runtime, NULL_TREE);
}
}
tree
lookup_type_for_runtime (tree type)
{
tree *slot;
/* If TYPE is NOP_EXPR, it means that it already is a runtime type. */
if (TREE_CODE (type) == NOP_EXPR)
return type;
slot = (tree *) htab_find_slot_with_hash (type_to_runtime_map, type,
TREE_HASH (type), NO_INSERT);
/* We should have always inserted the data earlier. */
return TREE_VALUE (*slot);
}
/* Represent an entry in @TTypes for either catch actions
or exception filter actions. */
struct ttypes_filter {
tree t;
int filter;
};
/* Compare ENTRY (a ttypes_filter entry in the hash table) with DATA
(a tree) for a @TTypes type node we are thinking about adding. */
static int
ttypes_filter_eq (const void *pentry, const void *pdata)
{
const struct ttypes_filter *const entry
= (const struct ttypes_filter *) pentry;
const_tree const data = (const_tree) pdata;
return entry->t == data;
}
static hashval_t
ttypes_filter_hash (const void *pentry)
{
const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry;
return TREE_HASH (entry->t);
}
/* Compare ENTRY with DATA (both struct ttypes_filter) for a @TTypes
exception specification list we are thinking about adding. */
/* ??? Currently we use the type lists in the order given. Someone
should put these in some canonical order. */
static int
ehspec_filter_eq (const void *pentry, const void *pdata)
{
const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry;
const struct ttypes_filter *data = (const struct ttypes_filter *) pdata;
return type_list_equal (entry->t, data->t);
}
/* Hash function for exception specification lists. */
static hashval_t
ehspec_filter_hash (const void *pentry)
{
const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry;
hashval_t h = 0;
tree list;
for (list = entry->t; list ; list = TREE_CHAIN (list))
h = (h << 5) + (h >> 27) + TREE_HASH (TREE_VALUE (list));
return h;
}
/* Add TYPE (which may be NULL) to cfun->eh->ttype_data, using TYPES_HASH
to speed up the search. Return the filter value to be used. */
static int
add_ttypes_entry (htab_t ttypes_hash, tree type)
{
struct ttypes_filter **slot, *n;
slot = (struct ttypes_filter **)
htab_find_slot_with_hash (ttypes_hash, type, TREE_HASH (type), INSERT);
if ((n = *slot) == NULL)
{
/* Filter value is a 1 based table index. */
n = XNEW (struct ttypes_filter);
n->t = type;
n->filter = VEC_length (tree, cfun->eh->ttype_data) + 1;
*slot = n;
VEC_safe_push (tree, gc, cfun->eh->ttype_data, type);
}
return n->filter;
}
/* Add LIST to cfun->eh->ehspec_data, using EHSPEC_HASH and TYPES_HASH
to speed up the search. Return the filter value to be used. */
static int
add_ehspec_entry (htab_t ehspec_hash, htab_t ttypes_hash, tree list)
{
struct ttypes_filter **slot, *n;
struct ttypes_filter dummy;
dummy.t = list;
slot = (struct ttypes_filter **)
htab_find_slot (ehspec_hash, &dummy, INSERT);
if ((n = *slot) == NULL)
{
int len;
if (targetm.arm_eabi_unwinder)
len = VEC_length (tree, cfun->eh->ehspec_data.arm_eabi);
else
len = VEC_length (uchar, cfun->eh->ehspec_data.other);
/* Filter value is a -1 based byte index into a uleb128 buffer. */
n = XNEW (struct ttypes_filter);
n->t = list;
n->filter = -(len + 1);
*slot = n;
/* Generate a 0 terminated list of filter values. */
for (; list ; list = TREE_CHAIN (list))
{
if (targetm.arm_eabi_unwinder)
VEC_safe_push (tree, gc, cfun->eh->ehspec_data.arm_eabi,
TREE_VALUE (list));
else
{
/* Look up each type in the list and encode its filter
value as a uleb128. */
push_uleb128 (&cfun->eh->ehspec_data.other,
add_ttypes_entry (ttypes_hash, TREE_VALUE (list)));
}
}
if (targetm.arm_eabi_unwinder)
VEC_safe_push (tree, gc, cfun->eh->ehspec_data.arm_eabi, NULL_TREE);
else
VEC_safe_push (uchar, gc, cfun->eh->ehspec_data.other, 0);
}
return n->filter;
}
/* Generate the action filter values to be used for CATCH and
ALLOWED_EXCEPTIONS regions. When using dwarf2 exception regions,
we use lots of landing pads, and so every type or list can share
the same filter value, which saves table space. */
void
assign_filter_values (void)
{
int i;
htab_t ttypes, ehspec;
eh_region r;
eh_catch c;
cfun->eh->ttype_data = VEC_alloc (tree, gc, 16);
if (targetm.arm_eabi_unwinder)
cfun->eh->ehspec_data.arm_eabi = VEC_alloc (tree, gc, 64);
else
cfun->eh->ehspec_data.other = VEC_alloc (uchar, gc, 64);
ttypes = htab_create (31, ttypes_filter_hash, ttypes_filter_eq, free);
ehspec = htab_create (31, ehspec_filter_hash, ehspec_filter_eq, free);
for (i = 1; VEC_iterate (eh_region, cfun->eh->region_array, i, r); ++i)
{
if (r == NULL)
continue;
switch (r->type)
{
case ERT_TRY:
for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
{
/* Whatever type_list is (NULL or true list), we build a list
of filters for the region. */
c->filter_list = NULL_TREE;
if (c->type_list != NULL)
{
/* Get a filter value for each of the types caught and store
them in the region's dedicated list. */
tree tp_node = c->type_list;
for ( ; tp_node; tp_node = TREE_CHAIN (tp_node))
{
int flt = add_ttypes_entry (ttypes, TREE_VALUE (tp_node));
tree flt_node = build_int_cst (NULL_TREE, flt);
c->filter_list
= tree_cons (NULL_TREE, flt_node, c->filter_list);
}
}
else
{
/* Get a filter value for the NULL list also since it
will need an action record anyway. */
int flt = add_ttypes_entry (ttypes, NULL);
tree flt_node = build_int_cst (NULL_TREE, flt);
c->filter_list
= tree_cons (NULL_TREE, flt_node, NULL);
}
}
break;
case ERT_ALLOWED_EXCEPTIONS:
r->u.allowed.filter
= add_ehspec_entry (ehspec, ttypes, r->u.allowed.type_list);
break;
default:
break;
}
}
htab_delete (ttypes);
htab_delete (ehspec);
}
/* Emit SEQ into basic block just before INSN (that is assumed to be
first instruction of some existing BB and return the newly
produced block. */
static basic_block
emit_to_new_bb_before (rtx seq, rtx insn)
{
rtx last;
basic_block bb;
edge e;
edge_iterator ei;
/* If there happens to be a fallthru edge (possibly created by cleanup_cfg
call), we don't want it to go into newly created landing pad or other EH
construct. */
for (ei = ei_start (BLOCK_FOR_INSN (insn)->preds); (e = ei_safe_edge (ei)); )
if (e->flags & EDGE_FALLTHRU)
force_nonfallthru (e);
else
ei_next (&ei);
last = emit_insn_before (seq, insn);
if (BARRIER_P (last))
last = PREV_INSN (last);
bb = create_basic_block (seq, last, BLOCK_FOR_INSN (insn)->prev_bb);
update_bb_for_insn (bb);
bb->flags |= BB_SUPERBLOCK;
return bb;
}
/* Expand the extra code needed at landing pads for dwarf2 unwinding. */
static void
dw2_build_landing_pads (void)
{
int i;
eh_landing_pad lp;
for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i)
{
eh_region region;
basic_block bb;
rtx seq;
edge e;
if (lp == NULL || lp->post_landing_pad == NULL)
continue;
start_sequence ();
lp->landing_pad = gen_label_rtx ();
emit_label (lp->landing_pad);
LABEL_PRESERVE_P (lp->landing_pad) = 1;
#ifdef HAVE_exception_receiver
if (HAVE_exception_receiver)
emit_insn (gen_exception_receiver ());
else
#endif
#ifdef HAVE_nonlocal_goto_receiver
if (HAVE_nonlocal_goto_receiver)
emit_insn (gen_nonlocal_goto_receiver ());
else
#endif
{ /* Nothing */ }
region = lp->region;
if (region->exc_ptr_reg)
emit_move_insn (region->exc_ptr_reg,
gen_rtx_REG (ptr_mode, EH_RETURN_DATA_REGNO (0)));
if (region->filter_reg)
emit_move_insn (region->filter_reg,
gen_rtx_REG (targetm.eh_return_filter_mode (),
EH_RETURN_DATA_REGNO (1)));
seq = get_insns ();
end_sequence ();
bb = emit_to_new_bb_before (seq, label_rtx (lp->post_landing_pad));
e = make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
e->count = bb->count;
e->probability = REG_BR_PROB_BASE;
}
}
static VEC (int, heap) *sjlj_lp_call_site_index;
/* Process all active landing pads. Assign each one a compact dispatch
index, and a call-site index. */
static int
sjlj_assign_call_site_values (void)
{
htab_t ar_hash;
int i, disp_index;
eh_landing_pad lp;
crtl->eh.action_record_data = VEC_alloc (uchar, gc, 64);
ar_hash = htab_create (31, action_record_hash, action_record_eq, free);
disp_index = 0;
call_site_base = 1;
for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i)
if (lp && lp->post_landing_pad)
{
int action, call_site;
/* First: build the action table. */
action = collect_one_action_chain (ar_hash, lp->region);