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authorjason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>2001-04-25 00:23:10 +0000
committerjason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>2001-04-25 00:23:10 +0000
commit1639c6dbf222cbbe0010e5036ab6ec4bc2fe96e9 (patch)
treed82d77b522a5b8ca49b1c63739dd140b9d6f38dc /gcc/except.c
parenta846710f988f4a7ff983323a22958d58aec6168a (diff)
downloadgcc-1639c6dbf222cbbe0010e5036ab6ec4bc2fe96e9.tar.gz
* except.c (reachable_handlers): Step out one level from a RESX.
* except.c (struct eh_region): Rename 'last' to 'resume'. (mark_eh_region, duplicate_eh_region_1): Adjust. (expand_eh_region_end_cleanup): Remember the jump, not the barrier. (build_post_landing_pads): Likewise. (expand_end_catch, expand_eh_region_end_allowed): Don't set it. (expand_eh_region_end_must_not_throw): Likewise. (connect_post_landing_pads): Thread (only) regions with non-deleted resume insns. * except.c (expand_eh_region_end_cleanup): Save the EH return data registers around the cleanup. (get_exception_filter): New fn. (finish_eh_generation): Use it. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@41528 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/except.c')
-rw-r--r--gcc/except.c130
1 files changed, 72 insertions, 58 deletions
diff --git a/gcc/except.c b/gcc/except.c
index 5404f4989e7..790f2ce4ec5 100644
--- a/gcc/except.c
+++ b/gcc/except.c
@@ -181,14 +181,18 @@ struct eh_region
} fixup;
} u;
- /* The region of code generated, or contained within, the region. */
- rtx label, last;
+ /* Entry point for this region's handler before landing pads are built. */
+ rtx label;
- /* Entry point for this region from the runtime eh library. */
+ /* Entry point for this region's handler from the runtime eh library. */
rtx landing_pad;
- /* Entry point for this region from an inner region. */
+ /* Entry point for this region's handler from an inner region. */
rtx post_landing_pad;
+
+ /* The RESX insn for handing off control to the next outermost handler,
+ if appropriate. */
+ rtx resume;
};
/* Used to save exception status for each function. */
@@ -251,6 +255,8 @@ static tree lookup_type_for_runtime PARAMS ((tree));
static struct eh_region *expand_eh_region_end PARAMS ((void));
+static rtx get_exception_filter PARAMS ((void));
+
static void collect_eh_region_array PARAMS ((void));
static void resolve_fixup_regions PARAMS ((void));
static void remove_fixup_regions PARAMS ((void));
@@ -497,7 +503,7 @@ mark_eh_region (region)
}
ggc_mark_rtx (region->label);
- ggc_mark_rtx (region->last);
+ ggc_mark_rtx (region->resume);
ggc_mark_rtx (region->landing_pad);
ggc_mark_rtx (region->post_landing_pad);
}
@@ -711,6 +717,7 @@ expand_eh_region_end_cleanup (handler)
{
struct eh_region *region;
rtx around_label;
+ rtx data_save[2];
if (! doing_eh (0))
return;
@@ -728,19 +735,28 @@ expand_eh_region_end_cleanup (handler)
if (protect_cleanup_actions)
expand_eh_region_start ();
+ /* In case this cleanup involves an inline destructor with a try block in
+ it, we need to save the EH return data registers around it. */
+ data_save[0] = gen_reg_rtx (Pmode);
+ emit_move_insn (data_save[0], get_exception_pointer ());
+ data_save[1] = gen_reg_rtx (Pmode);
+ emit_move_insn (data_save[1], get_exception_filter ());
+
expand_expr (handler, const0_rtx, VOIDmode, 0);
+ emit_move_insn (cfun->eh->exc_ptr, data_save[0]);
+ emit_move_insn (cfun->eh->filter, data_save[1]);
+
if (protect_cleanup_actions)
expand_eh_region_end_must_not_throw (protect_cleanup_actions);
/* We delay the generation of the _Unwind_Resume until we generate
landing pads. We emit a marker here so as to get good control
flow data in the meantime. */
- emit_jump_insn (gen_rtx_RESX (VOIDmode, region->region_number));
+ region->resume
+ = emit_jump_insn (gen_rtx_RESX (VOIDmode, region->region_number));
emit_barrier ();
- region->last = get_last_insn ();
-
emit_label (around_label);
}
@@ -812,8 +828,6 @@ expand_end_catch ()
try_region = cfun->eh->try_region;
emit_jump (try_region->u.try.continue_label);
-
- catch_region->last = get_last_insn ();
}
/* End a sequence of catch handlers for a try block. */
@@ -864,8 +878,6 @@ expand_eh_region_end_allowed (allowed, failure)
emit_label (region->label);
expand_expr (failure, const0_rtx, VOIDmode, EXPAND_NORMAL);
- region->last = get_last_insn ();
-
emit_label (around_label);
}
@@ -901,8 +913,6 @@ expand_eh_region_end_must_not_throw (failure)
emit_label (region->label);
expand_expr (failure, const0_rtx, VOIDmode, EXPAND_NORMAL);
- region->last = get_last_insn ();
-
emit_label (around_label);
}
@@ -948,7 +958,7 @@ expand_eh_region_end_fixup (handler)
fixup->u.fixup.cleanup_exp = handler;
}
-/* Return a tree expression for a pointer to the exception object
+/* Return an rtl expression for a pointer to the exception object
within a handler. */
rtx
@@ -963,6 +973,20 @@ get_exception_pointer ()
return exc_ptr;
}
+/* Return an rtl expression for the exception dispatch filter
+ within a handler. */
+
+static rtx
+get_exception_filter ()
+{
+ rtx filter = cfun->eh->filter;
+ if (! filter)
+ {
+ filter = gen_reg_rtx (Pmode);
+ cfun->eh->filter = filter;
+ }
+ return filter;
+}
/* Begin a region that will contain entries created with
add_partial_entry. */
@@ -1323,10 +1347,10 @@ duplicate_eh_region_1 (o, map)
if (o->label)
n->label = get_label_from_map (map, CODE_LABEL_NUMBER (o->label));
- if (o->last)
+ if (o->resume)
{
- n->last = map->insn_map[INSN_UID (o->last)];
- if (n->last == NULL)
+ n->resume = map->insn_map[INSN_UID (o->resume)];
+ if (n->resume == NULL)
abort ();
}
@@ -1719,10 +1743,17 @@ build_post_landing_pads ()
}
}
+ /* We delay the generation of the _Unwind_Resume until we generate
+ landing pads. We emit a marker here so as to get good control
+ flow data in the meantime. */
+ region->resume
+ = emit_jump_insn (gen_rtx_RESX (VOIDmode, region->region_number));
+ emit_barrier ();
+
seq = get_insns ();
end_sequence ();
- region->last = emit_insns_before (seq, region->u.try.catch->label);
+ emit_insns_before (seq, region->u.try.catch->label);
break;
case ERT_ALLOWED_EXCEPTIONS:
@@ -1737,10 +1768,17 @@ build_post_landing_pads ()
EQ, NULL_RTX, word_mode, 0, 0,
region->label);
+ /* We delay the generation of the _Unwind_Resume until we generate
+ landing pads. We emit a marker here so as to get good control
+ flow data in the meantime. */
+ region->resume
+ = emit_jump_insn (gen_rtx_RESX (VOIDmode, region->region_number));
+ emit_barrier ();
+
seq = get_insns ();
end_sequence ();
- region->last = emit_insns_before (seq, region->label);
+ emit_insns_before (seq, region->label);
break;
case ERT_CLEANUP:
@@ -1759,6 +1797,9 @@ build_post_landing_pads ()
}
}
+/* Replace RESX patterns with jumps to the next handler if any, or calls to
+ _Unwind_Resume otherwise. */
+
static void
connect_post_landing_pads ()
{
@@ -1768,44 +1809,15 @@ connect_post_landing_pads ()
{
struct eh_region *region = cfun->eh->region_array[i];
struct eh_region *outer;
- rtx before = NULL_RTX, after = NULL_RTX, seq;
+ rtx seq;
/* Mind we don't process a region more than once. */
if (!region || region->region_number != i)
continue;
- switch (region->type)
- {
- case ERT_CLEANUP:
- after = region->last;
- if (GET_CODE (after) == BARRIER
- && GET_CODE (PREV_INSN (after)) == JUMP_INSN
- && GET_CODE (PATTERN (PREV_INSN (after))) == RESX)
- {
- before = PREV_INSN (after);
- after = NULL_RTX;
- }
- break;
-
- case ERT_TRY:
- after = region->last;
- break;
-
- case ERT_ALLOWED_EXCEPTIONS:
- before = region->label;
- break;
-
- case ERT_MUST_NOT_THROW:
- case ERT_CATCH:
- case ERT_THROW:
- continue;
-
- default:
- abort ();
- }
-
- /* If there's no fallthru, no need to add branches. */
- if (after && GET_CODE (after) == BARRIER)
+ /* If there is no RESX, or it has been deleted by flow, there's
+ nothing to fix up. */
+ if (! region->resume || INSN_DELETED_P (region->resume))
continue;
/* Search for another landing pad in this function. */
@@ -1823,10 +1835,9 @@ connect_post_landing_pads ()
seq = get_insns ();
end_sequence ();
- if (before)
- emit_insns_before (seq, before);
- else
- emit_insns_after (seq, after);
+ emit_insns_before (seq, region->resume);
+
+ /* Leave the RESX to be deleted by flow. */
}
}
@@ -2329,7 +2340,7 @@ finish_eh_generation ()
/* These registers are used by the landing pads. Make sure they
have been generated. */
get_exception_pointer ();
- cfun->eh->filter = gen_reg_rtx (word_mode);
+ get_exception_filter ();
/* Construct the landing pads. */
@@ -2709,6 +2720,9 @@ reachable_handlers (insn)
type_thrown = region->u.throw.type;
region = region->outer;
}
+ else if (GET_CODE (insn) == JUMP_INSN
+ && GET_CODE (PATTERN (insn)) == RESX)
+ region = region->outer;
for (; region; region = region->outer)
if (reachable_next_level (region, type_thrown, &info) >= RNL_CAUGHT)
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