/* Exception handling semantics and decomposition for trees.
- Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
This file is part of GCC.
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
-#include "rtl.h"
-#include "tm_p.h"
#include "flags.h"
#include "function.h"
#include "except.h"
+#include "pointer-set.h"
#include "tree-flow.h"
-#include "tree-dump.h"
#include "tree-inline.h"
-#include "tree-iterator.h"
#include "tree-pass.h"
-#include "timevar.h"
#include "langhooks.h"
#include "ggc.h"
-#include "toplev.h"
+#include "diagnostic-core.h"
#include "gimple.h"
+#include "target.h"
+#include "cfgloop.h"
/* In some instances a tree and a gimple need to be stored in a same table,
i.e. in hash tables. This is a structure to do this. */
/* Misc functions used in this file. */
-/* Compare and hash for any structure which begins with a canonical
- pointer. Assumes all pointers are interchangeable, which is sort
- of already assumed by gcc elsewhere IIRC. */
-
-static int
-struct_ptr_eq (const void *a, const void *b)
-{
- const void * const * x = (const void * const *) a;
- const void * const * y = (const void * const *) b;
- return *x == *y;
-}
-
-static hashval_t
-struct_ptr_hash (const void *a)
-{
- const void * const * x = (const void * const *) a;
- return (size_t)*x >> 4;
-}
-
-
-/* Remember and lookup EH region data for arbitrary statements.
+/* Remember and lookup EH landing pad data for arbitrary statements.
Really this means any statement that could_throw_p. We could
stuff this information into the stmt_ann data structure, but:
compared to those that can. We should be saving some amount
of space by only allocating memory for those that can throw. */
-static void
-record_stmt_eh_region (struct eh_region_d *region, gimple t)
-{
- if (!region)
- return;
-
- add_stmt_to_eh_region (t, get_eh_region_number (region));
-}
-
-
-/* Add statement T in function IFUN to EH region NUM. */
+/* Add statement T in function IFUN to landing pad NUM. */
void
-add_stmt_to_eh_region_fn (struct function *ifun, gimple t, int num)
+add_stmt_to_eh_lp_fn (struct function *ifun, gimple t, int num)
{
struct throw_stmt_node *n;
void **slot;
- gcc_assert (num >= 0);
- gcc_assert (gimple_code (t) != GIMPLE_RESX);
+ gcc_assert (num != 0);
- n = GGC_NEW (struct throw_stmt_node);
+ n = ggc_alloc_throw_stmt_node ();
n->stmt = t;
- n->region_nr = num;
+ n->lp_nr = num;
if (!get_eh_throw_stmt_table (ifun))
set_eh_throw_stmt_table (ifun, htab_create_ggc (31, struct_ptr_hash,
*slot = n;
}
-
-/* Add statement T in the current function (cfun) to EH region number
- NUM. */
+/* Add statement T in the current function (cfun) to EH landing pad NUM. */
void
-add_stmt_to_eh_region (gimple t, int num)
+add_stmt_to_eh_lp (gimple t, int num)
+{
+ add_stmt_to_eh_lp_fn (cfun, t, num);
+}
+
+/* Add statement T to the single EH landing pad in REGION. */
+
+static void
+record_stmt_eh_region (eh_region region, gimple t)
{
- add_stmt_to_eh_region_fn (cfun, t, num);
+ if (region == NULL)
+ return;
+ if (region->type == ERT_MUST_NOT_THROW)
+ add_stmt_to_eh_lp_fn (cfun, t, -region->index);
+ else
+ {
+ eh_landing_pad lp = region->landing_pads;
+ if (lp == NULL)
+ lp = gen_eh_landing_pad (region);
+ else
+ gcc_assert (lp->next_lp == NULL);
+ add_stmt_to_eh_lp_fn (cfun, t, lp->index);
+ }
}
-/* Remove statement T in function IFUN from the EH region holding it. */
+/* Remove statement T in function IFUN from its EH landing pad. */
bool
-remove_stmt_from_eh_region_fn (struct function *ifun, gimple t)
+remove_stmt_from_eh_lp_fn (struct function *ifun, gimple t)
{
struct throw_stmt_node dummy;
void **slot;
}
-/* Remove statement T in the current function (cfun) from the EH
- region holding it. */
+/* Remove statement T in the current function (cfun) from its
+ EH landing pad. */
bool
-remove_stmt_from_eh_region (gimple t)
+remove_stmt_from_eh_lp (gimple t)
{
- return remove_stmt_from_eh_region_fn (cfun, t);
+ return remove_stmt_from_eh_lp_fn (cfun, t);
}
/* Determine if statement T is inside an EH region in function IFUN.
- Return the EH region number if found, return -2 if IFUN does not
- have an EH table and -1 if T could not be found in IFUN's EH region
- table. */
+ Positive numbers indicate a landing pad index; negative numbers
+ indicate a MUST_NOT_THROW region index; zero indicates that the
+ statement is not recorded in the region table. */
int
-lookup_stmt_eh_region_fn (struct function *ifun, gimple t)
+lookup_stmt_eh_lp_fn (struct function *ifun, gimple t)
{
struct throw_stmt_node *p, n;
- if (!get_eh_throw_stmt_table (ifun))
- return -2;
+ if (ifun->eh->throw_stmt_table == NULL)
+ return 0;
n.stmt = t;
- p = (struct throw_stmt_node *) htab_find (get_eh_throw_stmt_table (ifun), &n);
- return (p ? p->region_nr : -1);
-}
-
-
-/* Determine if statement T is inside an EH region in the current
- function (cfun). Return the EH region number if found, return -2
- if cfun does not have an EH table and -1 if T could not be found in
- cfun's EH region table. */
-
-int
-lookup_stmt_eh_region (gimple t)
-{
- /* We can get called from initialized data when -fnon-call-exceptions
- is on; prevent crash. */
- if (!cfun)
- return -1;
-
- return lookup_stmt_eh_region_fn (cfun, t);
+ p = (struct throw_stmt_node *) htab_find (ifun->eh->throw_stmt_table, &n);
+ return p ? p->lp_nr : 0;
}
-
-/* Determine if expression T is inside an EH region in the current
- function (cfun). Return the EH region number if found, return -2
- if IFUN does not have an EH table and -1 if T could not be found in
- IFUN's EH region table. */
+/* Likewise, but always use the current function. */
int
-lookup_expr_eh_region (tree t)
+lookup_stmt_eh_lp (gimple t)
{
/* We can get called from initialized data when -fnon-call-exceptions
is on; prevent crash. */
if (!cfun)
- return -1;
-
- if (!get_eh_throw_stmt_table (cfun))
- return -2;
-
- if (t && EXPR_P (t))
- {
- tree_ann_common_t ann = tree_common_ann (t);
- if (ann)
- return (int) ann->rn;
- }
-
- return -1;
+ return 0;
+ return lookup_stmt_eh_lp_fn (cfun, t);
}
-
/* First pass of EH node decomposition. Build up a tree of GIMPLE_TRY_FINALLY
nodes and LABEL_DECL nodes. We will use this during the second phase to
determine if a goto leaves the body of a TRY_FINALLY_EXPR node. */
when deciding whether a GOTO to a certain LABEL_DECL (which is a
tree) leaves the TRY block, its necessary to record a tree in
this field. Thus a treemple is used. */
- treemple child;
+ treemple child;
gimple parent;
};
static void
collect_finally_tree (gimple stmt, gimple region);
-/* Go through the gimple sequence. Works with collect_finally_tree to
+/* Go through the gimple sequence. Works with collect_finally_tree to
record all GIMPLE_LABEL and GIMPLE_TRY statements. */
static void
collect_finally_tree_1 (gimple_eh_filter_failure (stmt), region);
break;
+ case GIMPLE_EH_ELSE:
+ collect_finally_tree_1 (gimple_eh_else_n_body (stmt), region);
+ collect_finally_tree_1 (gimple_eh_else_e_body (stmt), region);
+ break;
+
default:
/* A type, a decl, or some kind of statement that we're not
interested in. Don't walk them. */
The eh region creation is straight-forward, but frobbing all the gotos
and such into shape isn't. */
+/* The sequence into which we record all EH stuff. This will be
+ placed at the end of the function when we're all done. */
+static gimple_seq eh_seq;
+
+/* Record whether an EH region contains something that can throw,
+ indexed by EH region number. */
+static bitmap eh_region_may_contain_throw_map;
+
/* The GOTO_QUEUE is is an array of GIMPLE_GOTO and GIMPLE_RETURN
statements that are seen to escape this GIMPLE_TRY_FINALLY node.
The idea is to record a gimple statement for everything except for
/* What's "current" while constructing the eh region tree. These
correspond to variables of the same name in cfun->eh, which we
don't have easy access to. */
- struct eh_region_d *cur_region;
+ eh_region cur_region;
+
+ /* What's "current" for the purposes of __builtin_eh_pointer. For
+ a CATCH, this is the associated TRY. For an EH_FILTER, this is
+ the associated ALLOWED_EXCEPTIONS, etc. */
+ eh_region ehp_region;
/* Processing of TRY_FINALLY requires a bit more state. This is
split out into a separate structure so that we don't have to
in the collect_finally_tree data structures. */
gimple try_finally_expr;
gimple top_p;
+
/* While lowering a top_p usually it is expanded into multiple statements,
thus we need the following field to store them. */
gimple_seq top_p_seq;
struct leh_state *outer;
/* The exception region created for it. */
- struct eh_region_d *region;
+ eh_region region;
/* The goto queue. */
struct goto_queue_node *goto_queue;
though subsequent transformations may have cleared that flag. */
tree fallthru_label;
- /* A label that has been registered with except.c to be the
- landing pad for this try block. */
- tree eh_label;
-
/* True if it is possible to fall out the bottom of the try block.
Cleared if the fallthru is converted to a goto. */
bool may_fallthru;
bool may_throw;
};
-static gimple_seq lower_eh_filter (struct leh_state *, gimple);
+static gimple_seq lower_eh_must_not_throw (struct leh_state *, gimple);
/* Search for STMT in the goto queue. Return the replacement,
or null if the statement isn't in the queue. */
#define LARGE_GOTO_QUEUE 20
-static void lower_eh_constructs_1 (struct leh_state *state, gimple_seq seq);
+static void lower_eh_constructs_1 (struct leh_state *state, gimple_seq *seq);
static gimple_seq
find_goto_replacement (struct leh_tf_state *tf, treemple stmt)
/* The real work of replace_goto_queue. Returns with TSI updated to
point to the next statement. */
-static void replace_goto_queue_stmt_list (gimple_seq, struct leh_tf_state *);
+static void replace_goto_queue_stmt_list (gimple_seq *, struct leh_tf_state *);
static void
replace_goto_queue_1 (gimple stmt, struct leh_tf_state *tf,
break;
case GIMPLE_TRY:
- replace_goto_queue_stmt_list (gimple_try_eval (stmt), tf);
- replace_goto_queue_stmt_list (gimple_try_cleanup (stmt), tf);
+ replace_goto_queue_stmt_list (gimple_try_eval_ptr (stmt), tf);
+ replace_goto_queue_stmt_list (gimple_try_cleanup_ptr (stmt), tf);
break;
case GIMPLE_CATCH:
- replace_goto_queue_stmt_list (gimple_catch_handler (stmt), tf);
+ replace_goto_queue_stmt_list (gimple_catch_handler_ptr (stmt), tf);
break;
case GIMPLE_EH_FILTER:
- replace_goto_queue_stmt_list (gimple_eh_filter_failure (stmt), tf);
+ replace_goto_queue_stmt_list (gimple_eh_filter_failure_ptr (stmt), tf);
+ break;
+ case GIMPLE_EH_ELSE:
+ replace_goto_queue_stmt_list (gimple_eh_else_n_body_ptr (stmt), tf);
+ replace_goto_queue_stmt_list (gimple_eh_else_e_body_ptr (stmt), tf);
break;
default:
/* A subroutine of replace_goto_queue. Handles GIMPLE_SEQ. */
static void
-replace_goto_queue_stmt_list (gimple_seq seq, struct leh_tf_state *tf)
+replace_goto_queue_stmt_list (gimple_seq *seq, struct leh_tf_state *tf)
{
- gimple_stmt_iterator gsi = gsi_start (seq);
+ gimple_stmt_iterator gsi = gsi_start (*seq);
while (!gsi_end_p (gsi))
replace_goto_queue_1 (gsi_stmt (gsi), tf, &gsi);
{
if (tf->goto_queue_active == 0)
return;
- replace_goto_queue_stmt_list (tf->top_p_seq, tf);
+ replace_goto_queue_stmt_list (&tf->top_p_seq, tf);
+ replace_goto_queue_stmt_list (&eh_seq, tf);
}
/* Add a new record to the goto queue contained in TF. NEW_STMT is the
labels. */
new_stmt = stmt;
record_in_goto_queue (tf, new_stmt, index, true);
-
}
/* For any GIMPLE_GOTO or GIMPLE_RETURN, decide whether it leaves a try_finally
#define verify_norecord_switch_expr(state, switch_expr)
#endif
-/* Redirect a RETURN_EXPR pointed to by STMT_P to FINLAB. Place in CONT_P
- whatever is needed to finish the return. If MOD is non-null, insert it
- before the new branch. RETURN_VALUE_P is a cache containing a temporary
- variable to be used in manipulating the value returned from the function. */
+/* Redirect a RETURN_EXPR pointed to by Q to FINLAB. If MOD is
+ non-null, insert it before the new branch. */
static void
-do_return_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod,
- tree *return_value_p)
+do_return_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod)
{
- tree ret_expr;
gimple x;
- /* In the case of a return, the queue node must be a gimple statement. */
+ /* In the case of a return, the queue node must be a gimple statement. */
gcc_assert (!q->is_label);
- ret_expr = gimple_return_retval (q->stmt.g);
+ /* Note that the return value may have already been computed, e.g.,
- if (ret_expr)
- {
- if (!*return_value_p)
- *return_value_p = ret_expr;
- else
- gcc_assert (*return_value_p == ret_expr);
- q->cont_stmt = q->stmt.g;
- /* The nasty part about redirecting the return value is that the
- return value itself is to be computed before the FINALLY block
- is executed. e.g.
-
- int x;
- int foo (void)
- {
- x = 0;
- try {
- return x;
- } finally {
- x++;
- }
- }
-
- should return 0, not 1. Arrange for this to happen by copying
- computed the return value into a local temporary. This also
- allows us to redirect multiple return statements through the
- same destination block; whether this is a net win or not really
- depends, I guess, but it does make generation of the switch in
- lower_try_finally_switch easier. */
-
- if (TREE_CODE (ret_expr) == RESULT_DECL)
+ int x;
+ int foo (void)
{
- if (!*return_value_p)
- *return_value_p = ret_expr;
- else
- gcc_assert (*return_value_p == ret_expr);
- q->cont_stmt = q->stmt.g;
+ x = 0;
+ try {
+ return x;
+ } finally {
+ x++;
+ }
}
- else
- gcc_unreachable ();
- }
- else
- /* If we don't return a value, all return statements are the same. */
- q->cont_stmt = q->stmt.g;
- if (!q->repl_stmt)
- q->repl_stmt = gimple_seq_alloc ();
+ should return 0, not 1. We don't have to do anything to make
+ this happens because the return value has been placed in the
+ RESULT_DECL already. */
+
+ q->cont_stmt = q->stmt.g;
if (mod)
gimple_seq_add_seq (&q->repl_stmt, mod);
gimple x;
gcc_assert (q->is_label);
- if (!q->repl_stmt)
- q->repl_stmt = gimple_seq_alloc ();
- q->cont_stmt = gimple_build_goto (VEC_index (tree, tf->dest_array,q->index));
+ q->cont_stmt = gimple_build_goto (VEC_index (tree, tf->dest_array, q->index));
if (mod)
gimple_seq_add_seq (&q->repl_stmt, mod);
gimple_seq_add_stmt (&q->repl_stmt, x);
}
+/* Emit a standard landing pad sequence into SEQ for REGION. */
+
+static void
+emit_post_landing_pad (gimple_seq *seq, eh_region region)
+{
+ eh_landing_pad lp = region->landing_pads;
+ gimple x;
+
+ if (lp == NULL)
+ lp = gen_eh_landing_pad (region);
+
+ lp->post_landing_pad = create_artificial_label (UNKNOWN_LOCATION);
+ EH_LANDING_PAD_NR (lp->post_landing_pad) = lp->index;
+
+ x = gimple_build_label (lp->post_landing_pad);
+ gimple_seq_add_stmt (seq, x);
+}
+
+/* Emit a RESX statement into SEQ for REGION. */
+
+static void
+emit_resx (gimple_seq *seq, eh_region region)
+{
+ gimple x = gimple_build_resx (region->index);
+ gimple_seq_add_stmt (seq, x);
+ if (region->outer)
+ record_stmt_eh_region (region->outer, x);
+}
+
+/* Emit an EH_DISPATCH statement into SEQ for REGION. */
+
+static void
+emit_eh_dispatch (gimple_seq *seq, eh_region region)
+{
+ gimple x = gimple_build_eh_dispatch (region->index);
+ gimple_seq_add_stmt (seq, x);
+}
+
+/* Note that the current EH region may contain a throw, or a
+ call to a function which itself may contain a throw. */
+
+static void
+note_eh_region_may_contain_throw (eh_region region)
+{
+ while (bitmap_set_bit (eh_region_may_contain_throw_map, region->index))
+ {
+ if (region->type == ERT_MUST_NOT_THROW)
+ break;
+ region = region->outer;
+ if (region == NULL)
+ break;
+ }
+}
+
+/* Check if REGION has been marked as containing a throw. If REGION is
+ NULL, this predicate is false. */
+
+static inline bool
+eh_region_may_contain_throw (eh_region r)
+{
+ return r && bitmap_bit_p (eh_region_may_contain_throw_map, r->index);
+}
+
/* We want to transform
try { body; } catch { stuff; }
to
- body; goto over; lab: stuff; over:
-
- TP is a GIMPLE_TRY node. LAB is the label that
+ normal_seqence:
+ body;
+ over:
+ eh_seqence:
+ landing_pad:
+ stuff;
+ goto over;
+
+ TP is a GIMPLE_TRY node. REGION is the region whose post_landing_pad
should be placed before the second operand, or NULL. OVER is
an existing label that should be put at the exit, or NULL. */
static gimple_seq
-frob_into_branch_around (gimple tp, tree lab, tree over)
+frob_into_branch_around (gimple tp, eh_region region, tree over)
{
gimple x;
gimple_seq cleanup, result;
cleanup = gimple_try_cleanup (tp);
result = gimple_try_eval (tp);
- if (gimple_seq_may_fallthru (result))
+ if (region)
+ emit_post_landing_pad (&eh_seq, region);
+
+ if (gimple_seq_may_fallthru (cleanup))
{
if (!over)
over = create_artificial_label (loc);
x = gimple_build_goto (over);
- gimple_seq_add_stmt (&result, x);
- }
-
- if (lab)
- {
- x = gimple_build_label (lab);
- gimple_seq_add_stmt (&result, x);
+ gimple_seq_add_stmt (&cleanup, x);
}
-
- gimple_seq_add_seq (&result, cleanup);
+ gimple_seq_add_seq (&eh_seq, cleanup);
if (over)
{
return label;
}
-/* A subroutine of lower_try_finally. If lang_protect_cleanup_actions
- returns non-null, then the language requires that the exception path out
- of a try_finally be treated specially. To wit: the code within the
- finally block may not itself throw an exception. We have two choices here.
- First we can duplicate the finally block and wrap it in a must_not_throw
- region. Second, we can generate code like
+/* A subroutine of lower_try_finally. If FINALLY consits of a
+ GIMPLE_EH_ELSE node, return it. */
+
+static inline gimple
+get_eh_else (gimple_seq finally)
+{
+ gimple x = gimple_seq_first_stmt (finally);
+ if (gimple_code (x) == GIMPLE_EH_ELSE)
+ {
+ gcc_assert (gimple_seq_singleton_p (finally));
+ return x;
+ }
+ return NULL;
+}
+
+/* A subroutine of lower_try_finally. If the eh_protect_cleanup_actions
+ langhook returns non-null, then the language requires that the exception
+ path out of a try_finally be treated specially. To wit: the code within
+ the finally block may not itself throw an exception. We have two choices
+ here. First we can duplicate the finally block and wrap it in a
+ must_not_throw region. Second, we can generate code like
try {
finally_block;
struct leh_state *this_state,
struct leh_tf_state *tf)
{
- gimple protect_cleanup_actions;
+ tree protect_cleanup_actions;
gimple_stmt_iterator gsi;
bool finally_may_fallthru;
gimple_seq finally;
- gimple x;
+ gimple x, eh_else;
/* First check for nothing to do. */
- if (lang_protect_cleanup_actions)
- protect_cleanup_actions = lang_protect_cleanup_actions ();
- else
- protect_cleanup_actions = NULL;
+ if (lang_hooks.eh_protect_cleanup_actions == NULL)
+ return;
+ protect_cleanup_actions = lang_hooks.eh_protect_cleanup_actions ();
+ if (protect_cleanup_actions == NULL)
+ return;
finally = gimple_try_cleanup (tf->top_p);
-
- /* If the EH case of the finally block can fall through, this may be a
- structure of the form
- try {
- try {
- throw ...;
- } cleanup {
- try {
- throw ...;
- } catch (...) {
- }
- }
- } catch (...) {
- yyy;
- }
- E.g. with an inline destructor with an embedded try block. In this
- case we must save the runtime EH data around the nested exception.
-
- This complication means that any time the previous runtime data might
- be used (via fallthru from the finally) we handle the eh case here,
- whether or not protect_cleanup_actions is active. */
-
- finally_may_fallthru = gimple_seq_may_fallthru (finally);
- if (!finally_may_fallthru && !protect_cleanup_actions)
- return;
+ eh_else = get_eh_else (finally);
/* Duplicate the FINALLY block. Only need to do this for try-finally,
- and not for cleanups. */
- if (this_state)
+ and not for cleanups. If we've got an EH_ELSE, extract it now. */
+ if (eh_else)
+ {
+ finally = gimple_eh_else_e_body (eh_else);
+ gimple_try_set_cleanup (tf->top_p, gimple_eh_else_n_body (eh_else));
+ }
+ else if (this_state)
finally = lower_try_finally_dup_block (finally, outer_state);
+ finally_may_fallthru = gimple_seq_may_fallthru (finally);
/* If this cleanup consists of a TRY_CATCH_EXPR with TRY_CATCH_IS_CLEANUP
set, the handler of the TRY_CATCH_EXPR is another cleanup which ought
MUST_NOT_THROW filter. */
gsi = gsi_start (finally);
x = gsi_stmt (gsi);
- if (protect_cleanup_actions
- && gimple_code (x) == GIMPLE_TRY
+ if (gimple_code (x) == GIMPLE_TRY
&& gimple_try_kind (x) == GIMPLE_TRY_CATCH
&& gimple_try_catch_is_cleanup (x))
{
gsi_remove (&gsi, false);
}
- /* Resume execution after the exception. Adding this now lets
- lower_eh_filter not add unnecessary gotos, as it is clear that
- we never fallthru from this copy of the finally block. */
- if (finally_may_fallthru)
- {
- tree save_eptr, save_filt;
- tree tmp;
-
- save_eptr = create_tmp_var (ptr_type_node, "save_eptr");
- save_filt = create_tmp_var (integer_type_node, "save_filt");
-
- gsi = gsi_start (finally);
- tmp = build0 (EXC_PTR_EXPR, ptr_type_node);
- x = gimple_build_assign (save_eptr, tmp);
- gsi_insert_before (&gsi, x, GSI_CONTINUE_LINKING);
-
- tmp = build0 (FILTER_EXPR, integer_type_node);
- x = gimple_build_assign (save_filt, tmp);
- gsi_insert_before (&gsi, x, GSI_CONTINUE_LINKING);
-
- gsi = gsi_last (finally);
- tmp = build0 (EXC_PTR_EXPR, ptr_type_node);
- x = gimple_build_assign (tmp, save_eptr);
- gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
-
- tmp = build0 (FILTER_EXPR, integer_type_node);
- x = gimple_build_assign (tmp, save_filt);
- gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
-
- x = gimple_build_resx (get_eh_region_number (tf->region));
- gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
- }
-
/* Wrap the block with protect_cleanup_actions as the action. */
- if (protect_cleanup_actions)
- {
- gimple_seq seq = NULL, failure = NULL;
-
- gimple_seq_add_stmt (&failure, protect_cleanup_actions);
- x = gimple_build_eh_filter (NULL, failure);
- gimple_eh_filter_set_must_not_throw (x, 1);
-
- gimple_seq_add_stmt (&seq, x);
- x = gimple_build_try (finally, seq, GIMPLE_TRY_CATCH);
- finally = lower_eh_filter (outer_state, x);
- }
- else
- lower_eh_constructs_1 (outer_state, finally);
-
- /* Hook this up to the end of the existing try block. If we
- previously fell through the end, we'll have to branch around.
- This means adding a new goto, and adding it to the queue. */
-
- gsi = gsi_last (gimple_try_eval (tf->top_p));
-
- if (tf->may_fallthru)
- {
- tree tmp;
- tmp = lower_try_finally_fallthru_label (tf);
- x = gimple_build_goto (tmp);
- gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
-
- if (this_state)
- maybe_record_in_goto_queue (this_state, x);
-
- tf->may_fallthru = false;
- }
-
- x = gimple_build_label (tf->eh_label);
- gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
- gsi_insert_seq_after (&gsi, finally, GSI_CONTINUE_LINKING);
+ x = gimple_build_eh_must_not_throw (protect_cleanup_actions);
+ x = gimple_build_try (finally, gimple_seq_alloc_with_stmt (x),
+ GIMPLE_TRY_CATCH);
+ finally = lower_eh_must_not_throw (outer_state, x);
+
+ /* Drop all of this into the exception sequence. */
+ emit_post_landing_pad (&eh_seq, tf->region);
+ gimple_seq_add_seq (&eh_seq, finally);
+ if (finally_may_fallthru)
+ emit_resx (&eh_seq, tf->region);
/* Having now been handled, EH isn't to be considered with
the rest of the outgoing edges. */
lower_try_finally_nofallthru (struct leh_state *state,
struct leh_tf_state *tf)
{
- tree lab, return_val;
- gimple x;
+ tree lab;
+ gimple x, eh_else;
gimple_seq finally;
struct goto_queue_node *q, *qe;
- if (tf->may_throw)
- lab = tf->eh_label;
- else
- lab = create_artificial_label (gimple_location (tf->try_finally_expr));
+ lab = create_artificial_label (gimple_location (tf->try_finally_expr));
/* We expect that tf->top_p is a GIMPLE_TRY. */
finally = gimple_try_cleanup (tf->top_p);
x = gimple_build_label (lab);
gimple_seq_add_stmt (&tf->top_p_seq, x);
- return_val = NULL;
q = tf->goto_queue;
qe = q + tf->goto_queue_active;
for (; q < qe; ++q)
if (q->index < 0)
- do_return_redirection (q, lab, NULL, &return_val);
+ do_return_redirection (q, lab, NULL);
else
do_goto_redirection (q, lab, NULL, tf);
replace_goto_queue (tf);
- lower_eh_constructs_1 (state, finally);
- gimple_seq_add_seq (&tf->top_p_seq, finally);
+ /* Emit the finally block into the stream. Lower EH_ELSE at this time. */
+ eh_else = get_eh_else (finally);
+ if (eh_else)
+ {
+ finally = gimple_eh_else_n_body (eh_else);
+ lower_eh_constructs_1 (state, &finally);
+ gimple_seq_add_seq (&tf->top_p_seq, finally);
+
+ if (tf->may_throw)
+ {
+ finally = gimple_eh_else_e_body (eh_else);
+ lower_eh_constructs_1 (state, &finally);
+
+ emit_post_landing_pad (&eh_seq, tf->region);
+ gimple_seq_add_seq (&eh_seq, finally);
+ }
+ }
+ else
+ {
+ lower_eh_constructs_1 (state, &finally);
+ gimple_seq_add_seq (&tf->top_p_seq, finally);
+
+ if (tf->may_throw)
+ {
+ emit_post_landing_pad (&eh_seq, tf->region);
+
+ x = gimple_build_goto (lab);
+ gimple_seq_add_stmt (&eh_seq, x);
+ }
+ }
}
/* A subroutine of lower_try_finally. We have determined that there is
finally = gimple_try_cleanup (tf->top_p);
tf->top_p_seq = gimple_try_eval (tf->top_p);
- lower_eh_constructs_1 (state, finally);
+ /* Since there's only one destination, and the destination edge can only
+ either be EH or non-EH, that implies that all of our incoming edges
+ are of the same type. Therefore we can lower EH_ELSE immediately. */
+ x = get_eh_else (finally);
+ if (x)
+ {
+ if (tf->may_throw)
+ finally = gimple_eh_else_e_body (x);
+ else
+ finally = gimple_eh_else_n_body (x);
+ }
+
+ lower_eh_constructs_1 (state, &finally);
if (tf->may_throw)
{
/* Only reachable via the exception edge. Add the given label to
the head of the FINALLY block. Append a RESX at the end. */
-
- x = gimple_build_label (tf->eh_label);
- gimple_seq_add_stmt (&tf->top_p_seq, x);
-
- gimple_seq_add_seq (&tf->top_p_seq, finally);
-
- x = gimple_build_resx (get_eh_region_number (tf->region));
-
- gimple_seq_add_stmt (&tf->top_p_seq, x);
-
+ emit_post_landing_pad (&eh_seq, tf->region);
+ gimple_seq_add_seq (&eh_seq, finally);
+ emit_resx (&eh_seq, tf->region);
return;
}
if (tf->may_return)
{
/* Reachable by return expressions only. Redirect them. */
- tree return_val = NULL;
for (; q < qe; ++q)
- do_return_redirection (q, finally_label, NULL, &return_val);
+ do_return_redirection (q, finally_label, NULL);
replace_goto_queue (tf);
}
else
gimple_seq finally;
gimple_seq new_stmt;
gimple_seq seq;
- gimple x;
+ gimple x, eh_else;
tree tmp;
location_t tf_loc = gimple_location (tf->try_finally_expr);
finally = gimple_try_cleanup (tf->top_p);
+
+ /* Notice EH_ELSE, and simplify some of the remaining code
+ by considering FINALLY to be the normal return path only. */
+ eh_else = get_eh_else (finally);
+ if (eh_else)
+ finally = gimple_eh_else_n_body (eh_else);
+
tf->top_p_seq = gimple_try_eval (tf->top_p);
new_stmt = NULL;
if (tf->may_fallthru)
{
seq = lower_try_finally_dup_block (finally, state);
- lower_eh_constructs_1 (state, seq);
+ lower_eh_constructs_1 (state, &seq);
gimple_seq_add_seq (&new_stmt, seq);
tmp = lower_try_finally_fallthru_label (tf);
if (tf->may_throw)
{
- x = gimple_build_label (tf->eh_label);
- gimple_seq_add_stmt (&new_stmt, x);
-
- seq = lower_try_finally_dup_block (finally, state);
- lower_eh_constructs_1 (state, seq);
- gimple_seq_add_seq (&new_stmt, seq);
+ /* We don't need to copy the EH path of EH_ELSE,
+ since it is only emitted once. */
+ if (eh_else)
+ seq = gimple_eh_else_e_body (eh_else);
+ else
+ seq = lower_try_finally_dup_block (finally, state);
+ lower_eh_constructs_1 (state, &seq);
- x = gimple_build_resx (get_eh_region_number (tf->region));
- gimple_seq_add_stmt (&new_stmt, x);
+ emit_post_landing_pad (&eh_seq, tf->region);
+ gimple_seq_add_seq (&eh_seq, seq);
+ emit_resx (&eh_seq, tf->region);
}
if (tf->goto_queue)
{
struct goto_queue_node *q, *qe;
- tree return_val = NULL;
int return_index, index;
struct labels_s
{
= create_artificial_label (tf_loc);
if (index == return_index)
- do_return_redirection (q, lab, NULL, &return_val);
+ do_return_redirection (q, lab, NULL);
else
do_goto_redirection (q, lab, NULL, tf);
gimple_seq_add_stmt (&new_stmt, x);
seq = lower_try_finally_dup_block (finally, state);
- lower_eh_constructs_1 (state, seq);
+ lower_eh_constructs_1 (state, &seq);
gimple_seq_add_seq (&new_stmt, seq);
gimple_seq_add_stmt (&new_stmt, q->cont_stmt);
lab = labels[index].label;
if (index == return_index)
- do_return_redirection (q, lab, NULL, &return_val);
+ do_return_redirection (q, lab, NULL);
else
do_goto_redirection (q, lab, NULL, tf);
}
-
+
replace_goto_queue (tf);
free (labels);
}
lower_try_finally_switch (struct leh_state *state, struct leh_tf_state *tf)
{
struct goto_queue_node *q, *qe;
- tree return_val = NULL;
tree finally_tmp, finally_label;
int return_index, eh_index, fallthru_index;
int nlabels, ndests, j, last_case_index;
tree last_case;
VEC (tree,heap) *case_label_vec;
- gimple_seq switch_body;
- gimple x;
+ gimple_seq switch_body = NULL;
+ gimple x, eh_else;
tree tmp;
gimple switch_stmt;
gimple_seq finally;
/* The location of the finally block. */
location_t finally_loc;
- switch_body = gimple_seq_alloc ();
+ finally = gimple_try_cleanup (tf->top_p);
+ eh_else = get_eh_else (finally);
/* Mash the TRY block to the head of the chain. */
- finally = gimple_try_cleanup (tf->top_p);
tf->top_p_seq = gimple_try_eval (tf->top_p);
/* The location of the finally is either the last stmt in the finally
block or the location of the TRY_FINALLY itself. */
- finally_loc = gimple_seq_last_stmt (tf->top_p_seq) != NULL ?
- gimple_location (gimple_seq_last_stmt (tf->top_p_seq))
- : tf_loc;
+ x = gimple_seq_last_stmt (finally);
+ finally_loc = x ? gimple_location (x) : tf_loc;
/* Lower the finally block itself. */
- lower_eh_constructs_1 (state, finally);
+ lower_eh_constructs_1 (state, &finally);
/* Prepare for switch statement generation. */
nlabels = VEC_length (tree, tf->dest_array);
return_index = nlabels;
eh_index = return_index + tf->may_return;
- fallthru_index = eh_index + tf->may_throw;
+ fallthru_index = eh_index + (tf->may_throw && !eh_else);
ndests = fallthru_index + tf->may_fallthru;
finally_tmp = create_tmp_var (integer_type_node, "finally_tmp");
/* Begin inserting code for getting to the finally block. Things
are done in this order to correspond to the sequence the code is
- layed out. */
+ laid out. */
if (tf->may_fallthru)
{
- x = gimple_build_assign (finally_tmp, build_int_cst (integer_type_node,
- fallthru_index));
+ x = gimple_build_assign (finally_tmp,
+ build_int_cst (integer_type_node,
+ fallthru_index));
gimple_seq_add_stmt (&tf->top_p_seq, x);
- if (tf->may_throw)
- {
- x = gimple_build_goto (finally_label);
- gimple_seq_add_stmt (&tf->top_p_seq, x);
- }
-
-
- last_case = build3 (CASE_LABEL_EXPR, void_type_node,
- build_int_cst (NULL_TREE, fallthru_index), NULL,
- create_artificial_label (tf_loc));
+ tmp = build_int_cst (integer_type_node, fallthru_index);
+ last_case = build_case_label (tmp, NULL,
+ create_artificial_label (tf_loc));
VEC_quick_push (tree, case_label_vec, last_case);
last_case_index++;
gimple_seq_add_stmt (&switch_body, x);
}
- if (tf->may_throw)
+ /* For EH_ELSE, emit the exception path (plus resx) now, then
+ subsequently we only need consider the normal path. */
+ if (eh_else)
{
- x = gimple_build_label (tf->eh_label);
- gimple_seq_add_stmt (&tf->top_p_seq, x);
+ if (tf->may_throw)
+ {
+ finally = gimple_eh_else_e_body (eh_else);
+ lower_eh_constructs_1 (state, &finally);
- x = gimple_build_assign (finally_tmp, build_int_cst (integer_type_node,
- eh_index));
- gimple_seq_add_stmt (&tf->top_p_seq, x);
+ emit_post_landing_pad (&eh_seq, tf->region);
+ gimple_seq_add_seq (&eh_seq, finally);
+ emit_resx (&eh_seq, tf->region);
+ }
+
+ finally = gimple_eh_else_n_body (eh_else);
+ }
+ else if (tf->may_throw)
+ {
+ emit_post_landing_pad (&eh_seq, tf->region);
+
+ x = gimple_build_assign (finally_tmp,
+ build_int_cst (integer_type_node, eh_index));
+ gimple_seq_add_stmt (&eh_seq, x);
- last_case = build3 (CASE_LABEL_EXPR, void_type_node,
- build_int_cst (NULL_TREE, eh_index), NULL,
- create_artificial_label (tf_loc));
+ x = gimple_build_goto (finally_label);
+ gimple_seq_add_stmt (&eh_seq, x);
+
+ tmp = build_int_cst (integer_type_node, eh_index);
+ last_case = build_case_label (tmp, NULL,
+ create_artificial_label (tf_loc));
VEC_quick_push (tree, case_label_vec, last_case);
last_case_index++;
x = gimple_build_label (CASE_LABEL (last_case));
- gimple_seq_add_stmt (&switch_body, x);
- x = gimple_build_resx (get_eh_region_number (tf->region));
- gimple_seq_add_stmt (&switch_body, x);
+ gimple_seq_add_stmt (&eh_seq, x);
+ emit_resx (&eh_seq, tf->region);
}
x = gimple_build_label (finally_label);
entrance through a particular edge. */
for (; q < qe; ++q)
{
- gimple_seq mod;
+ gimple_seq mod = NULL;
int switch_id;
unsigned int case_index;
- mod = gimple_seq_alloc ();
-
if (q->index < 0)
{
x = gimple_build_assign (finally_tmp,
build_int_cst (integer_type_node,
return_index));
gimple_seq_add_stmt (&mod, x);
- do_return_redirection (q, finally_label, mod, &return_val);
+ do_return_redirection (q, finally_label, mod);
switch_id = return_index;
}
else
{
tree case_lab;
void **slot;
- case_lab = build3 (CASE_LABEL_EXPR, void_type_node,
- build_int_cst (NULL_TREE, switch_id), NULL,
- NULL);
+ tmp = build_int_cst (integer_type_node, switch_id);
+ case_lab = build_case_label (tmp, NULL,
+ create_artificial_label (tf_loc));
/* We store the cont_stmt in the pointer map, so that we can recover
- it in the loop below. We don't create the new label while
- walking the goto_queue because pointers don't offer a stable
- order. */
+ it in the loop below. */
if (!cont_map)
cont_map = pointer_map_create ();
slot = pointer_map_insert (cont_map, case_lab);
}
for (j = last_case_index; j < last_case_index + nlabels; j++)
{
- tree label;
gimple cont_stmt;
void **slot;
gcc_assert (cont_map);
slot = pointer_map_contains (cont_map, last_case);
- /* As the comment above suggests, CASE_LABEL (last_case) was just a
- placeholder, it does not store an actual label, yet. */
gcc_assert (slot);
cont_stmt = *(gimple *) slot;
- label = create_artificial_label (tf_loc);
- CASE_LABEL (last_case) = label;
-
- x = gimple_build_label (label);
+ x = gimple_build_label (CASE_LABEL (last_case));
gimple_seq_add_stmt (&switch_body, x);
gimple_seq_add_stmt (&switch_body, cont_stmt);
maybe_record_in_goto_queue (state, cont_stmt);
/* Build the switch statement, setting last_case to be the default
label. */
- switch_stmt = gimple_build_switch_vec (finally_tmp, last_case,
- case_label_vec);
+ switch_stmt = gimple_build_switch (finally_tmp, last_case,
+ case_label_vec);
gimple_set_location (switch_stmt, finally_loc);
/* Need to link SWITCH_STMT after running replace_goto_queue
the estimate of the size of the switch machinery we'd have to add. */
static bool
-decide_copy_try_finally (int ndests, gimple_seq finally)
+decide_copy_try_finally (int ndests, bool may_throw, gimple_seq finally)
{
int f_estimate, sw_estimate;
+ gimple eh_else;
+
+ /* If there's an EH_ELSE involved, the exception path is separate
+ and really doesn't come into play for this computation. */
+ eh_else = get_eh_else (finally);
+ if (eh_else)
+ {
+ ndests -= may_throw;
+ finally = gimple_eh_else_n_body (eh_else);
+ }
if (!optimize)
- return false;
+ {
+ gimple_stmt_iterator gsi;
+
+ if (ndests == 1)
+ return true;
+
+ for (gsi = gsi_start (finally); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ if (!is_gimple_debug (stmt) && !gimple_clobber_p (stmt))
+ return false;
+ }
+ return true;
+ }
/* Finally estimate N times, plus N gotos. */
f_estimate = count_insns_seq (finally, &eni_size_weights);
return f_estimate < 40 || f_estimate * 2 < sw_estimate * 3;
}
+/* REG is the enclosing region for a possible cleanup region, or the region
+ itself. Returns TRUE if such a region would be unreachable.
+
+ Cleanup regions within a must-not-throw region aren't actually reachable
+ even if there are throwing stmts within them, because the personality
+ routine will call terminate before unwinding. */
+
+static bool
+cleanup_is_dead_in (eh_region reg)
+{
+ while (reg && reg->type == ERT_CLEANUP)
+ reg = reg->outer;
+ return (reg && reg->type == ERT_MUST_NOT_THROW);
+}
/* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_FINALLY nodes
to a sequence of labels and blocks, plus the exception region trees
struct leh_tf_state this_tf;
struct leh_state this_state;
int ndests;
- location_t tf_loc = gimple_location (tp);
+ gimple_seq old_eh_seq;
/* Process the try block. */
this_tf.try_finally_expr = tp;
this_tf.top_p = tp;
this_tf.outer = state;
- if (using_eh_for_cleanups_p)
- this_tf.region
- = gen_eh_region_cleanup (state->cur_region);
+ if (using_eh_for_cleanups_p && !cleanup_is_dead_in (state->cur_region))
+ {
+ this_tf.region = gen_eh_region_cleanup (state->cur_region);
+ this_state.cur_region = this_tf.region;
+ }
else
- this_tf.region = NULL;
+ {
+ this_tf.region = NULL;
+ this_state.cur_region = state->cur_region;
+ }
- this_state.cur_region = this_tf.region;
+ this_state.ehp_region = state->ehp_region;
this_state.tf = &this_tf;
- lower_eh_constructs_1 (&this_state, gimple_try_eval(tp));
+ old_eh_seq = eh_seq;
+ eh_seq = NULL;
+
+ lower_eh_constructs_1 (&this_state, gimple_try_eval_ptr (tp));
/* Determine if the try block is escaped through the bottom. */
this_tf.may_fallthru = gimple_seq_may_fallthru (gimple_try_eval (tp));
/* Determine if any exceptions are possible within the try block. */
- if (using_eh_for_cleanups_p)
- this_tf.may_throw = get_eh_region_may_contain_throw (this_tf.region);
+ if (this_tf.region)
+ this_tf.may_throw = eh_region_may_contain_throw (this_tf.region);
if (this_tf.may_throw)
- {
- this_tf.eh_label = create_artificial_label (tf_loc);
- set_eh_region_tree_label (this_tf.region, this_tf.eh_label);
- honor_protect_cleanup_actions (state, &this_state, &this_tf);
- }
+ honor_protect_cleanup_actions (state, &this_state, &this_tf);
/* Determine how many edges (still) reach the finally block. Or rather,
how many destinations are reached by the finally block. Use this to
/* We can easily special-case redirection to a single destination. */
else if (ndests == 1)
lower_try_finally_onedest (state, &this_tf);
- else if (decide_copy_try_finally (ndests, gimple_try_cleanup (tp)))
+ else if (decide_copy_try_finally (ndests, this_tf.may_throw,
+ gimple_try_cleanup (tp)))
lower_try_finally_copy (state, &this_tf);
else
lower_try_finally_switch (state, &this_tf);
}
VEC_free (tree, heap, this_tf.dest_array);
- if (this_tf.goto_queue)
- free (this_tf.goto_queue);
+ free (this_tf.goto_queue);
if (this_tf.goto_queue_map)
pointer_map_destroy (this_tf.goto_queue_map);
- return this_tf.top_p_seq;
+ /* If there was an old (aka outer) eh_seq, append the current eh_seq.
+ If there was no old eh_seq, then the append is trivially already done. */
+ if (old_eh_seq)
+ {
+ if (eh_seq == NULL)
+ eh_seq = old_eh_seq;
+ else
+ {
+ gimple_seq new_eh_seq = eh_seq;
+ eh_seq = old_eh_seq;
+ gimple_seq_add_seq(&eh_seq, new_eh_seq);
+ }
+ }
+
+ return this_tf.top_p_seq;
}
/* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_CATCH with a
static gimple_seq
lower_catch (struct leh_state *state, gimple tp)
{
- struct eh_region_d *try_region;
- struct leh_state this_state;
+ eh_region try_region = NULL;
+ struct leh_state this_state = *state;
gimple_stmt_iterator gsi;
tree out_label;
+ gimple_seq new_seq, cleanup;
+ gimple x;
location_t try_catch_loc = gimple_location (tp);
- try_region = gen_eh_region_try (state->cur_region);
- this_state.cur_region = try_region;
- this_state.tf = state->tf;
-
- lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
-
- if (!get_eh_region_may_contain_throw (try_region))
+ if (flag_exceptions)
{
- return gimple_try_eval (tp);
+ try_region = gen_eh_region_try (state->cur_region);
+ this_state.cur_region = try_region;
}
+ lower_eh_constructs_1 (&this_state, gimple_try_eval_ptr (tp));
+
+ if (!eh_region_may_contain_throw (try_region))
+ return gimple_try_eval (tp);
+
+ new_seq = NULL;
+ emit_eh_dispatch (&new_seq, try_region);
+ emit_resx (&new_seq, try_region);
+
+ this_state.cur_region = state->cur_region;
+ this_state.ehp_region = try_region;
+
out_label = NULL;
- for (gsi = gsi_start (gimple_try_cleanup (tp)); !gsi_end_p (gsi); )
+ cleanup = gimple_try_cleanup (tp);
+ for (gsi = gsi_start (cleanup);
+ !gsi_end_p (gsi);
+ gsi_next (&gsi))
{
- struct eh_region_d *catch_region;
- tree eh_label;
- gimple x, gcatch;
+ eh_catch c;
+ gimple gcatch;
+ gimple_seq handler;
gcatch = gsi_stmt (gsi);
- catch_region = gen_eh_region_catch (try_region,
- gimple_catch_types (gcatch));
+ c = gen_eh_region_catch (try_region, gimple_catch_types (gcatch));
- this_state.cur_region = catch_region;
- lower_eh_constructs_1 (&this_state, gimple_catch_handler (gcatch));
+ handler = gimple_catch_handler (gcatch);
+ lower_eh_constructs_1 (&this_state, &handler);
- eh_label = create_artificial_label (try_catch_loc);
- set_eh_region_tree_label (catch_region, eh_label);
+ c->label = create_artificial_label (UNKNOWN_LOCATION);
+ x = gimple_build_label (c->label);
+ gimple_seq_add_stmt (&new_seq, x);
- x = gimple_build_label (eh_label);
- gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+ gimple_seq_add_seq (&new_seq, handler);
- if (gimple_seq_may_fallthru (gimple_catch_handler (gcatch)))
+ if (gimple_seq_may_fallthru (new_seq))
{
if (!out_label)
out_label = create_artificial_label (try_catch_loc);
x = gimple_build_goto (out_label);
- gimple_seq_add_stmt (gimple_catch_handler_ptr (gcatch), x);
+ gimple_seq_add_stmt (&new_seq, x);
}
-
- gsi_insert_seq_before (&gsi, gimple_catch_handler (gcatch),
- GSI_SAME_STMT);
- gsi_remove (&gsi, false);
+ if (!c->type_list)
+ break;
}
- return frob_into_branch_around (tp, NULL, out_label);
+ gimple_try_set_cleanup (tp, new_seq);
+
+ return frob_into_branch_around (tp, try_region, out_label);
}
/* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with a
static gimple_seq
lower_eh_filter (struct leh_state *state, gimple tp)
{
- struct leh_state this_state;
- struct eh_region_d *this_region;
- gimple inner;
- tree eh_label;
+ struct leh_state this_state = *state;
+ eh_region this_region = NULL;
+ gimple inner, x;
+ gimple_seq new_seq;
inner = gimple_seq_first_stmt (gimple_try_cleanup (tp));
- if (gimple_eh_filter_must_not_throw (inner))
- this_region = gen_eh_region_must_not_throw (state->cur_region);
- else
- this_region = gen_eh_region_allowed (state->cur_region,
- gimple_eh_filter_types (inner));
- this_state = *state;
- this_state.cur_region = this_region;
+ if (flag_exceptions)
+ {
+ this_region = gen_eh_region_allowed (state->cur_region,
+ gimple_eh_filter_types (inner));
+ this_state.cur_region = this_region;
+ }
+
+ lower_eh_constructs_1 (&this_state, gimple_try_eval_ptr (tp));
+
+ if (!eh_region_may_contain_throw (this_region))
+ return gimple_try_eval (tp);
+
+ new_seq = NULL;
+ this_state.cur_region = state->cur_region;
+ this_state.ehp_region = this_region;
+
+ emit_eh_dispatch (&new_seq, this_region);
+ emit_resx (&new_seq, this_region);
+
+ this_region->u.allowed.label = create_artificial_label (UNKNOWN_LOCATION);
+ x = gimple_build_label (this_region->u.allowed.label);
+ gimple_seq_add_stmt (&new_seq, x);
+
+ lower_eh_constructs_1 (&this_state, gimple_eh_filter_failure_ptr (inner));
+ gimple_seq_add_seq (&new_seq, gimple_eh_filter_failure (inner));
- lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
+ gimple_try_set_cleanup (tp, new_seq);
- if (!get_eh_region_may_contain_throw (this_region))
+ return frob_into_branch_around (tp, this_region, NULL);
+}
+
+/* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with
+ an GIMPLE_EH_MUST_NOT_THROW to a sequence of labels and blocks,
+ plus the exception region trees that record all the magic. */
+
+static gimple_seq
+lower_eh_must_not_throw (struct leh_state *state, gimple tp)
+{
+ struct leh_state this_state = *state;
+
+ if (flag_exceptions)
{
- return gimple_try_eval (tp);
- }
+ gimple inner = gimple_seq_first_stmt (gimple_try_cleanup (tp));
+ eh_region this_region;
+
+ this_region = gen_eh_region_must_not_throw (state->cur_region);
+ this_region->u.must_not_throw.failure_decl
+ = gimple_eh_must_not_throw_fndecl (inner);
+ this_region->u.must_not_throw.failure_loc = gimple_location (tp);
- lower_eh_constructs_1 (state, gimple_eh_filter_failure (inner));
- gimple_try_set_cleanup (tp, gimple_eh_filter_failure (inner));
+ /* In order to get mangling applied to this decl, we must mark it
+ used now. Otherwise, pass_ipa_free_lang_data won't think it
+ needs to happen. */
+ TREE_USED (this_region->u.must_not_throw.failure_decl) = 1;
- eh_label = create_artificial_label (gimple_location (inner));
- set_eh_region_tree_label (this_region, eh_label);
+ this_state.cur_region = this_region;
+ }
+
+ lower_eh_constructs_1 (&this_state, gimple_try_eval_ptr (tp));
- return frob_into_branch_around (tp, eh_label, NULL);
+ return gimple_try_eval (tp);
}
/* Implement a cleanup expression. This is similar to try-finally,
static gimple_seq
lower_cleanup (struct leh_state *state, gimple tp)
{
- struct leh_state this_state;
- struct eh_region_d *this_region;
+ struct leh_state this_state = *state;
+ eh_region this_region = NULL;
struct leh_tf_state fake_tf;
gimple_seq result;
+ bool cleanup_dead = cleanup_is_dead_in (state->cur_region);
- /* If not using eh, then exception-only cleanups are no-ops. */
- if (!flag_exceptions)
+ if (flag_exceptions && !cleanup_dead)
{
- result = gimple_try_eval (tp);
- lower_eh_constructs_1 (state, result);
- return result;
+ this_region = gen_eh_region_cleanup (state->cur_region);
+ this_state.cur_region = this_region;
}
- this_region = gen_eh_region_cleanup (state->cur_region);
- this_state = *state;
- this_state.cur_region = this_region;
-
- lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
+ lower_eh_constructs_1 (&this_state, gimple_try_eval_ptr (tp));
- if (!get_eh_region_may_contain_throw (this_region))
- {
- return gimple_try_eval (tp);
- }
+ if (cleanup_dead || !eh_region_may_contain_throw (this_region))
+ return gimple_try_eval (tp);
/* Build enough of a try-finally state so that we can reuse
honor_protect_cleanup_actions. */
fake_tf.may_fallthru = gimple_seq_may_fallthru (gimple_try_eval (tp));
fake_tf.may_throw = true;
- fake_tf.eh_label = create_artificial_label (gimple_location (tp));
- set_eh_region_tree_label (this_region, fake_tf.eh_label);
-
honor_protect_cleanup_actions (state, NULL, &fake_tf);
if (fake_tf.may_throw)
{
/* In this case honor_protect_cleanup_actions had nothing to do,
and we should process this normally. */
- lower_eh_constructs_1 (state, gimple_try_cleanup (tp));
- result = frob_into_branch_around (tp, fake_tf.eh_label,
- fake_tf.fallthru_label);
+ lower_eh_constructs_1 (state, gimple_try_cleanup_ptr (tp));
+ result = frob_into_branch_around (tp, this_region,
+ fake_tf.fallthru_label);
}
else
{
return result;
}
-
-
-/* Main loop for lowering eh constructs. Also moves gsi to the next
+/* Main loop for lowering eh constructs. Also moves gsi to the next
statement. */
static void
switch (gimple_code (stmt))
{
case GIMPLE_CALL:
+ {
+ tree fndecl = gimple_call_fndecl (stmt);
+ tree rhs, lhs;
+
+ if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+ switch (DECL_FUNCTION_CODE (fndecl))
+ {
+ case BUILT_IN_EH_POINTER:
+ /* The front end may have generated a call to
+ __builtin_eh_pointer (0) within a catch region. Replace
+ this zero argument with the current catch region number. */
+ if (state->ehp_region)
+ {
+ tree nr = build_int_cst (integer_type_node,
+ state->ehp_region->index);
+ gimple_call_set_arg (stmt, 0, nr);
+ }
+ else
+ {
+ /* The user has dome something silly. Remove it. */
+ rhs = null_pointer_node;
+ goto do_replace;
+ }
+ break;
+
+ case BUILT_IN_EH_FILTER:
+ /* ??? This should never appear, but since it's a builtin it
+ is accessible to abuse by users. Just remove it and
+ replace the use with the arbitrary value zero. */
+ rhs = build_int_cst (TREE_TYPE (TREE_TYPE (fndecl)), 0);
+ do_replace:
+ lhs = gimple_call_lhs (stmt);
+ x = gimple_build_assign (lhs, rhs);
+ gsi_insert_before (gsi, x, GSI_SAME_STMT);
+ /* FALLTHRU */
+
+ case BUILT_IN_EH_COPY_VALUES:
+ /* Likewise this should not appear. Remove it. */
+ gsi_remove (gsi, true);
+ return;
+
+ default:
+ break;
+ }
+ }
+ /* FALLTHRU */
+
case GIMPLE_ASSIGN:
/* If the stmt can throw use a new temporary for the assignment
to a LHS. This makes sure the old value of the LHS is
- available on the EH edge. */
+ available on the EH edge. Only do so for statements that
+ potentially fall through (no noreturn calls e.g.), otherwise
+ this new assignment might create fake fallthru regions. */
if (stmt_could_throw_p (stmt)
&& gimple_has_lhs (stmt)
+ && gimple_stmt_may_fallthru (stmt)
&& !tree_could_throw_p (gimple_get_lhs (stmt))
&& is_gimple_reg_type (TREE_TYPE (gimple_get_lhs (stmt))))
{
else
{
x = gimple_seq_first_stmt (gimple_try_cleanup (stmt));
- switch (gimple_code (x))
+ if (!x)
{
- case GIMPLE_CATCH:
- replace = lower_catch (state, stmt);
- break;
- case GIMPLE_EH_FILTER:
- replace = lower_eh_filter (state, stmt);
- break;
- default:
- replace = lower_cleanup (state, stmt);
- break;
+ replace = gimple_try_eval (stmt);
+ lower_eh_constructs_1 (state, &replace);
}
+ else
+ switch (gimple_code (x))
+ {
+ case GIMPLE_CATCH:
+ replace = lower_catch (state, stmt);
+ break;
+ case GIMPLE_EH_FILTER:
+ replace = lower_eh_filter (state, stmt);
+ break;
+ case GIMPLE_EH_MUST_NOT_THROW:
+ replace = lower_eh_must_not_throw (state, stmt);
+ break;
+ case GIMPLE_EH_ELSE:
+ /* This code is only valid with GIMPLE_TRY_FINALLY. */
+ gcc_unreachable ();
+ default:
+ replace = lower_cleanup (state, stmt);
+ break;
+ }
}
/* Remove the old stmt and insert the transformed sequence
/* Return since we don't want gsi_next () */
return;
+ case GIMPLE_EH_ELSE:
+ /* We should be eliminating this in lower_try_finally et al. */
+ gcc_unreachable ();
+
default:
/* A type, a decl, or some kind of statement that we're not
interested in. Don't walk them. */
/* A helper to unwrap a gimple_seq and feed stmts to lower_eh_constructs_2. */
static void
-lower_eh_constructs_1 (struct leh_state *state, gimple_seq seq)
+lower_eh_constructs_1 (struct leh_state *state, gimple_seq *pseq)
{
gimple_stmt_iterator gsi;
- for (gsi = gsi_start (seq); !gsi_end_p (gsi);)
+ for (gsi = gsi_start (*pseq); !gsi_end_p (gsi);)
lower_eh_constructs_2 (state, &gsi);
}
lower_eh_constructs (void)
{
struct leh_state null_state;
+ gimple_seq bodyp;
- gimple_seq bodyp = gimple_body (current_function_decl);
+ bodyp = gimple_body (current_function_decl);
+ if (bodyp == NULL)
+ return 0;
finally_tree = htab_create (31, struct_ptr_hash, struct_ptr_eq, free);
+ eh_region_may_contain_throw_map = BITMAP_ALLOC (NULL);
+ memset (&null_state, 0, sizeof (null_state));
collect_finally_tree_1 (bodyp, NULL);
+ lower_eh_constructs_1 (&null_state, &bodyp);
+ gimple_set_body (current_function_decl, bodyp);
- memset (&null_state, 0, sizeof (null_state));
- lower_eh_constructs_1 (&null_state, bodyp);
+ /* We assume there's a return statement, or something, at the end of
+ the function, and thus ploping the EH sequence afterward won't
+ change anything. */
+ gcc_assert (!gimple_seq_may_fallthru (bodyp));
+ gimple_seq_add_seq (&bodyp, eh_seq);
+
+ /* We assume that since BODYP already existed, adding EH_SEQ to it
+ didn't change its value, and we don't have to re-set the function. */
+ gcc_assert (bodyp == gimple_body (current_function_decl));
htab_delete (finally_tree);
+ BITMAP_FREE (eh_region_may_contain_throw_map);
+ eh_seq = NULL;
+
+ /* If this function needs a language specific EH personality routine
+ and the frontend didn't already set one do so now. */
+ if (function_needs_eh_personality (cfun) == eh_personality_lang
+ && !DECL_FUNCTION_PERSONALITY (current_function_decl))
+ DECL_FUNCTION_PERSONALITY (current_function_decl)
+ = lang_hooks.eh_personality ();
- collect_eh_region_array ();
return 0;
}
PROP_gimple_leh, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_dump_func /* todo_flags_finish */
+ 0 /* todo_flags_finish */
}
};
-
\f
-/* Construct EH edges for STMT. */
+/* Create the multiple edges from an EH_DISPATCH statement to all of
+ the possible handlers for its EH region. Return true if there's
+ no fallthru edge; false if there is. */
-static void
-make_eh_edge (struct eh_region_d *region, void *data)
+bool
+make_eh_dispatch_edges (gimple stmt)
{
- gimple stmt;
- tree lab;
+ eh_region r;
+ eh_catch c;
basic_block src, dst;
- stmt = (gimple) data;
- lab = get_eh_region_tree_label (region);
-
+ r = get_eh_region_from_number (gimple_eh_dispatch_region (stmt));
src = gimple_bb (stmt);
- dst = label_to_block (lab);
-
- make_edge (src, dst, EDGE_EH);
-}
-/* See if STMT is call that might be inlined. */
+ switch (r->type)
+ {
+ case ERT_TRY:
+ for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
+ {
+ dst = label_to_block (c->label);
+ make_edge (src, dst, 0);
-static bool
-inlinable_call_p (gimple stmt)
-{
- tree decl;
- if (gimple_code (stmt) != GIMPLE_CALL)
- return false;
- if (cfun->after_inlining)
- return false;
- /* Indirect calls can be propagated to direct call
- and inlined. */
- decl = gimple_call_fndecl (stmt);
- if (!decl)
- return true;
- if (cgraph_function_flags_ready
- && cgraph_function_body_availability (cgraph_node (decl))
- < AVAIL_OVERWRITABLE)
- return false;
- return !DECL_UNINLINABLE (decl);
-}
+ /* A catch-all handler doesn't have a fallthru. */
+ if (c->type_list == NULL)
+ return false;
+ }
+ break;
-void
-make_eh_edges (gimple stmt)
-{
- int region_nr;
- bool is_resx;
- bool inlinable = false;
- basic_block bb;
+ case ERT_ALLOWED_EXCEPTIONS:
+ dst = label_to_block (r->u.allowed.label);
+ make_edge (src, dst, 0);
+ break;
- if (gimple_code (stmt) == GIMPLE_RESX)
- {
- region_nr = gimple_resx_region (stmt);
- is_resx = true;
- }
- else
- {
- region_nr = lookup_stmt_eh_region (stmt);
- if (region_nr < 0)
- return;
- is_resx = false;
- inlinable = inlinable_call_p (stmt);
+ default:
+ gcc_unreachable ();
}
- foreach_reachable_handler (region_nr, is_resx, inlinable, make_eh_edge, stmt);
-
- /* Make CFG profile more consistent assuming that exception will resume to first
- available EH handler. In practice this makes little difference, but we get
- fewer consistency errors in the dumps. */
- bb = gimple_bb (stmt);
- if (is_resx && EDGE_COUNT (bb->succs))
- EDGE_SUCC (bb, 0)->probability = REG_BR_PROB_BASE;
+ return true;
}
-/* Redirect EH edge E to NEW_BB. */
+/* Create the single EH edge from STMT to its nearest landing pad,
+ if there is such a landing pad within the current function. */
-edge
-redirect_eh_edge (edge e, basic_block new_bb)
+void
+make_eh_edges (gimple stmt)
{
- gimple stmt = gsi_stmt (gsi_last_bb (e->src));
- int region_nr, new_region_nr;
- bool is_resx;
- bool inlinable = false;
- tree label = gimple_block_label (new_bb);
- struct eh_region_d *r;
+ basic_block src, dst;
+ eh_landing_pad lp;
+ int lp_nr;
- if (gimple_code (stmt) == GIMPLE_RESX)
- {
- region_nr = gimple_resx_region (stmt);
- is_resx = true;
- }
- else
- {
- region_nr = lookup_stmt_eh_region (stmt);
- gcc_assert (region_nr >= 0);
- is_resx = false;
- inlinable = inlinable_call_p (stmt);
- }
+ lp_nr = lookup_stmt_eh_lp (stmt);
+ if (lp_nr <= 0)
+ return;
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Redirecting EH edge %i->%i to %i, region %i, resx %i\n",
- e->src->index, e->dest->index, new_bb->index, region_nr, is_resx);
- r = redirect_eh_edge_to_label (e, label, is_resx, inlinable, region_nr);
- new_region_nr = get_eh_region_number (r);
- if (new_region_nr != region_nr)
- {
- if (is_resx)
- gimple_resx_set_region (stmt, new_region_nr);
- else
- {
- remove_stmt_from_eh_region (stmt);
- add_stmt_to_eh_region (stmt, new_region_nr);
- }
- }
- e = ssa_redirect_edge (e, new_bb);
- return e;
+ lp = get_eh_landing_pad_from_number (lp_nr);
+ gcc_assert (lp != NULL);
+
+ src = gimple_bb (stmt);
+ dst = label_to_block (lp->post_landing_pad);
+ make_edge (src, dst, EDGE_EH);
}
-static bool mark_eh_edge_found_error;
+/* Do the work in redirecting EDGE_IN to NEW_BB within the EH region tree;
+ do not actually perform the final edge redirection.
-/* Mark edge make_eh_edge would create for given region by setting it aux
- field, output error if something goes wrong. */
+ CHANGE_REGION is true when we're being called from cleanup_empty_eh and
+ we intend to change the destination EH region as well; this means
+ EH_LANDING_PAD_NR must already be set on the destination block label.
+ If false, we're being called from generic cfg manipulation code and we
+ should preserve our place within the region tree. */
static void
-mark_eh_edge (struct eh_region_d *region, void *data)
+redirect_eh_edge_1 (edge edge_in, basic_block new_bb, bool change_region)
{
- gimple stmt;
- tree lab;
- basic_block src, dst;
+ eh_landing_pad old_lp, new_lp;
+ basic_block old_bb;
+ gimple throw_stmt;
+ int old_lp_nr, new_lp_nr;
+ tree old_label, new_label;
+ edge_iterator ei;
edge e;
- stmt = (gimple) data;
- lab = get_eh_region_tree_label (region);
+ old_bb = edge_in->dest;
+ old_label = gimple_block_label (old_bb);
+ old_lp_nr = EH_LANDING_PAD_NR (old_label);
+ gcc_assert (old_lp_nr > 0);
+ old_lp = get_eh_landing_pad_from_number (old_lp_nr);
- src = gimple_bb (stmt);
- dst = label_to_block (lab);
+ throw_stmt = last_stmt (edge_in->src);
+ gcc_assert (lookup_stmt_eh_lp (throw_stmt) == old_lp_nr);
- e = find_edge (src, dst);
- if (!e)
- {
- error ("EH edge %i->%i is missing", src->index, dst->index);
- mark_eh_edge_found_error = true;
- }
- else if (!(e->flags & EDGE_EH))
+ new_label = gimple_block_label (new_bb);
+
+ /* Look for an existing region that might be using NEW_BB already. */
+ new_lp_nr = EH_LANDING_PAD_NR (new_label);
+ if (new_lp_nr)
{
- error ("EH edge %i->%i miss EH flag", src->index, dst->index);
- mark_eh_edge_found_error = true;
+ new_lp = get_eh_landing_pad_from_number (new_lp_nr);
+ gcc_assert (new_lp);
+
+ /* Unless CHANGE_REGION is true, the new and old landing pad
+ had better be associated with the same EH region. */
+ gcc_assert (change_region || new_lp->region == old_lp->region);
}
- else if (e->aux)
+ else
{
- /* ??? might not be mistake. */
- error ("EH edge %i->%i has duplicated regions", src->index, dst->index);
- mark_eh_edge_found_error = true;
+ new_lp = NULL;
+ gcc_assert (!change_region);
}
- else
- e->aux = (void *)1;
-}
-/* Verify that BB containing STMT as the last statement, has precisely the
- edges that make_eh_edges would create. */
-
-bool
-verify_eh_edges (gimple stmt)
-{
- int region_nr;
- bool is_resx;
- basic_block bb = gimple_bb (stmt);
- edge_iterator ei;
- edge e;
- bool inlinable = false;
+ /* Notice when we redirect the last EH edge away from OLD_BB. */
+ FOR_EACH_EDGE (e, ei, old_bb->preds)
+ if (e != edge_in && (e->flags & EDGE_EH))
+ break;
- FOR_EACH_EDGE (e, ei, bb->succs)
- gcc_assert (!e->aux);
- mark_eh_edge_found_error = false;
- if (gimple_code (stmt) == GIMPLE_RESX)
+ if (new_lp)
{
- region_nr = gimple_resx_region (stmt);
- is_resx = true;
+ /* NEW_LP already exists. If there are still edges into OLD_LP,
+ there's nothing to do with the EH tree. If there are no more
+ edges into OLD_LP, then we want to remove OLD_LP as it is unused.
+ If CHANGE_REGION is true, then our caller is expecting to remove
+ the landing pad. */
+ if (e == NULL && !change_region)
+ remove_eh_landing_pad (old_lp);
}
else
{
- region_nr = lookup_stmt_eh_region (stmt);
- if (region_nr < 0)
- {
- FOR_EACH_EDGE (e, ei, bb->succs)
- if (e->flags & EDGE_EH)
- {
- error ("BB %i can not throw but has EH edges", bb->index);
- return true;
- }
- return false;
- }
- if (!stmt_could_throw_p (stmt))
+ /* No correct landing pad exists. If there are no more edges
+ into OLD_LP, then we can simply re-use the existing landing pad.
+ Otherwise, we have to create a new landing pad. */
+ if (e == NULL)
{
- error ("BB %i last statement has incorrectly set region", bb->index);
- return true;
+ EH_LANDING_PAD_NR (old_lp->post_landing_pad) = 0;
+ new_lp = old_lp;
}
- inlinable = inlinable_call_p (stmt);
- is_resx = false;
+ else
+ new_lp = gen_eh_landing_pad (old_lp->region);
+ new_lp->post_landing_pad = new_label;
+ EH_LANDING_PAD_NR (new_label) = new_lp->index;
}
- foreach_reachable_handler (region_nr, is_resx, inlinable, mark_eh_edge, stmt);
- FOR_EACH_EDGE (e, ei, bb->succs)
+ /* Maybe move the throwing statement to the new region. */
+ if (old_lp != new_lp)
+ {
+ remove_stmt_from_eh_lp (throw_stmt);
+ add_stmt_to_eh_lp (throw_stmt, new_lp->index);
+ }
+}
+
+/* Redirect EH edge E to NEW_BB. */
+
+edge
+redirect_eh_edge (edge edge_in, basic_block new_bb)
+{
+ redirect_eh_edge_1 (edge_in, new_bb, false);
+ return ssa_redirect_edge (edge_in, new_bb);
+}
+
+/* This is a subroutine of gimple_redirect_edge_and_branch. Update the
+ labels for redirecting a non-fallthru EH_DISPATCH edge E to NEW_BB.
+ The actual edge update will happen in the caller. */
+
+void
+redirect_eh_dispatch_edge (gimple stmt, edge e, basic_block new_bb)
+{
+ tree new_lab = gimple_block_label (new_bb);
+ bool any_changed = false;
+ basic_block old_bb;
+ eh_region r;
+ eh_catch c;
+
+ r = get_eh_region_from_number (gimple_eh_dispatch_region (stmt));
+ switch (r->type)
{
- if ((e->flags & EDGE_EH) && !e->aux)
+ case ERT_TRY:
+ for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
{
- error ("unnecessary EH edge %i->%i", bb->index, e->dest->index);
- mark_eh_edge_found_error = true;
- return true;
+ old_bb = label_to_block (c->label);
+ if (old_bb == e->dest)
+ {
+ c->label = new_lab;
+ any_changed = true;
+ }
}
- e->aux = NULL;
+ break;
+
+ case ERT_ALLOWED_EXCEPTIONS:
+ old_bb = label_to_block (r->u.allowed.label);
+ gcc_assert (old_bb == e->dest);
+ r->u.allowed.label = new_lab;
+ any_changed = true;
+ break;
+
+ default:
+ gcc_unreachable ();
}
- return mark_eh_edge_found_error;
+ gcc_assert (any_changed);
}
-
\f
/* Helper function for operation_could_trap_p and stmt_could_throw_p. */
return true;
return false;
+ case COMPLEX_EXPR:
+ case CONSTRUCTOR:
+ /* Constructing an object cannot trap. */
+ return false;
+
default:
/* Any floating arithmetic may trap. */
if (fp_operation && flag_trapping_math)
if (!expr)
return false;
-
+
code = TREE_CODE (expr);
t = TREE_TYPE (expr);
switch (code)
{
case TARGET_MEM_REF:
- /* For TARGET_MEM_REFs use the information based on the original
- reference. */
- expr = TMR_ORIGINAL (expr);
- code = TREE_CODE (expr);
- goto restart;
+ if (TREE_CODE (TMR_BASE (expr)) == ADDR_EXPR
+ && !TMR_INDEX (expr) && !TMR_INDEX2 (expr))
+ return false;
+ return !TREE_THIS_NOTRAP (expr);
case COMPONENT_REF:
case REALPART_EXPR:
base = TREE_OPERAND (expr, 0);
if (tree_could_trap_p (base))
return true;
-
if (TREE_THIS_NOTRAP (expr))
return false;
-
return !range_in_array_bounds_p (expr);
case ARRAY_REF:
base = TREE_OPERAND (expr, 0);
if (tree_could_trap_p (base))
return true;
-
if (TREE_THIS_NOTRAP (expr))
return false;
-
return !in_array_bounds_p (expr);
+ case MEM_REF:
+ if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR)
+ return false;
+ /* Fallthru. */
case INDIRECT_REF:
- case ALIGN_INDIRECT_REF:
- case MISALIGNED_INDIRECT_REF:
return !TREE_THIS_NOTRAP (expr);
case ASM_EXPR:
return TREE_THIS_VOLATILE (expr);
-
case CALL_EXPR:
t = get_callee_fndecl (expr);
/* Assume that calls to weak functions may trap. */
- if (!t || !DECL_P (t) || DECL_WEAK (t))
+ if (!t || !DECL_P (t))
return true;
+ if (DECL_WEAK (t))
+ return tree_could_trap_p (t);
+ return false;
+
+ case FUNCTION_DECL:
+ /* Assume that accesses to weak functions may trap, unless we know
+ they are certainly defined in current TU or in some other
+ LTO partition. */
+ if (DECL_WEAK (expr))
+ {
+ struct cgraph_node *node;
+ if (!DECL_EXTERNAL (expr))
+ return false;
+ node = cgraph_function_node (cgraph_get_node (expr), NULL);
+ if (node && node->symbol.in_other_partition)
+ return false;
+ return true;
+ }
+ return false;
+
+ case VAR_DECL:
+ /* Assume that accesses to weak vars may trap, unless we know
+ they are certainly defined in current TU or in some other
+ LTO partition. */
+ if (DECL_WEAK (expr))
+ {
+ struct varpool_node *node;
+ if (!DECL_EXTERNAL (expr))
+ return false;
+ node = varpool_variable_node (varpool_get_node (expr), NULL);
+ if (node && node->symbol.in_other_partition)
+ return false;
+ return true;
+ }
return false;
default:
|| TREE_CODE_CLASS (code) == tcc_unary
|| TREE_CODE_CLASS (code) == tcc_binary)
{
- t = gimple_expr_type (stmt);
+ if (is_gimple_assign (stmt)
+ && TREE_CODE_CLASS (code) == tcc_comparison)
+ t = TREE_TYPE (gimple_assign_rhs1 (stmt));
+ else if (gimple_code (stmt) == GIMPLE_COND)
+ t = TREE_TYPE (gimple_cond_lhs (stmt));
+ else
+ t = gimple_expr_type (stmt);
fp_operation = FLOAT_TYPE_P (t);
if (fp_operation)
{
bool
stmt_could_throw_p (gimple stmt)
{
- enum gimple_code code;
-
if (!flag_exceptions)
return false;
/* The only statements that can throw an exception are assignments,
- conditionals, calls and asms. */
- code = gimple_code (stmt);
- if (code != GIMPLE_ASSIGN
- && code != GIMPLE_COND
- && code != GIMPLE_CALL
- && code != GIMPLE_ASM)
- return false;
+ conditionals, calls, resx, and asms. */
+ switch (gimple_code (stmt))
+ {
+ case GIMPLE_RESX:
+ return true;
- /* If exceptions can only be thrown by function calls and STMT is not a
- GIMPLE_CALL, the statement cannot throw. */
- if (!flag_non_call_exceptions && code != GIMPLE_CALL)
- return false;
+ case GIMPLE_CALL:
+ return !gimple_call_nothrow_p (stmt);
- if (code == GIMPLE_ASSIGN || code == GIMPLE_COND)
- return stmt_could_throw_1_p (stmt);
- else if (is_gimple_call (stmt))
- return (gimple_call_flags (stmt) & ECF_NOTHROW) == 0;
- else if (gimple_code (stmt) == GIMPLE_ASM)
- return (gimple_asm_volatile_p (stmt));
- else
- gcc_unreachable ();
+ case GIMPLE_ASSIGN:
+ case GIMPLE_COND:
+ if (!cfun->can_throw_non_call_exceptions)
+ return false;
+ return stmt_could_throw_1_p (stmt);
- return false;
+ case GIMPLE_ASM:
+ if (!cfun->can_throw_non_call_exceptions)
+ return false;
+ return gimple_asm_volatile_p (stmt);
+
+ default:
+ return false;
+ }
}
return false;
if (TREE_CODE (t) == MODIFY_EXPR)
{
- if (flag_non_call_exceptions
- && tree_could_trap_p (TREE_OPERAND (t, 0)))
- return true;
+ if (cfun->can_throw_non_call_exceptions
+ && tree_could_trap_p (TREE_OPERAND (t, 0)))
+ return true;
t = TREE_OPERAND (t, 1);
}
t = TREE_OPERAND (t, 0);
if (TREE_CODE (t) == CALL_EXPR)
return (call_expr_flags (t) & ECF_NOTHROW) == 0;
- if (flag_non_call_exceptions)
+ if (cfun->can_throw_non_call_exceptions)
return tree_could_trap_p (t);
return false;
}
bool
stmt_can_throw_external (gimple stmt)
{
- int region_nr;
- bool is_resx = false;
- bool inlinable_call = false;
+ int lp_nr;
if (!stmt_could_throw_p (stmt))
return false;
- if (gimple_code (stmt) == GIMPLE_RESX)
- {
- region_nr = gimple_resx_region (stmt);
- is_resx = true;
- }
- else
- region_nr = lookup_stmt_eh_region (stmt);
-
- if (region_nr < 0)
- return true;
-
- return can_throw_external_1 (region_nr, is_resx, inlinable_call);
+ lp_nr = lookup_stmt_eh_lp (stmt);
+ return lp_nr == 0;
}
/* Return true if STMT can throw an exception that is caught within
bool
stmt_can_throw_internal (gimple stmt)
{
- int region_nr;
- bool is_resx = false;
- bool inlinable_call = false;
-
- if (gimple_code (stmt) == GIMPLE_RESX)
- {
- region_nr = gimple_resx_region (stmt);
- is_resx = true;
- }
- else
- {
- region_nr = lookup_stmt_eh_region (stmt);
- inlinable_call = inlinable_call_p (stmt);
- }
+ int lp_nr;
- if (region_nr < 0)
+ if (!stmt_could_throw_p (stmt))
return false;
- return can_throw_internal_1 (region_nr, is_resx, inlinable_call);
+ lp_nr = lookup_stmt_eh_lp (stmt);
+ return lp_nr > 0;
+}
+
+/* Given a statement STMT in IFUN, if STMT can no longer throw, then
+ remove any entry it might have from the EH table. Return true if
+ any change was made. */
+
+bool
+maybe_clean_eh_stmt_fn (struct function *ifun, gimple stmt)
+{
+ if (stmt_could_throw_p (stmt))
+ return false;
+ return remove_stmt_from_eh_lp_fn (ifun, stmt);
}
+/* Likewise, but always use the current function. */
+
+bool
+maybe_clean_eh_stmt (gimple stmt)
+{
+ return maybe_clean_eh_stmt_fn (cfun, stmt);
+}
/* Given a statement OLD_STMT and a new statement NEW_STMT that has replaced
OLD_STMT in the function, remove OLD_STMT from the EH table and put NEW_STMT
in the table if it should be in there. Return TRUE if a replacement was
done that my require an EH edge purge. */
-bool
-maybe_clean_or_replace_eh_stmt (gimple old_stmt, gimple new_stmt)
+bool
+maybe_clean_or_replace_eh_stmt (gimple old_stmt, gimple new_stmt)
{
- int region_nr = lookup_stmt_eh_region (old_stmt);
+ int lp_nr = lookup_stmt_eh_lp (old_stmt);
- if (region_nr >= 0)
+ if (lp_nr != 0)
{
bool new_stmt_could_throw = stmt_could_throw_p (new_stmt);
if (new_stmt == old_stmt && new_stmt_could_throw)
return false;
- remove_stmt_from_eh_region (old_stmt);
+ remove_stmt_from_eh_lp (old_stmt);
if (new_stmt_could_throw)
{
- add_stmt_to_eh_region (new_stmt, region_nr);
+ add_stmt_to_eh_lp (new_stmt, lp_nr);
return false;
}
else
return false;
}
-\f
+
+/* Given a statement OLD_STMT in OLD_FUN and a duplicate statement NEW_STMT
+ in NEW_FUN, copy the EH table data from OLD_STMT to NEW_STMT. The MAP
+ operand is the return value of duplicate_eh_regions. */
+
+bool
+maybe_duplicate_eh_stmt_fn (struct function *new_fun, gimple new_stmt,
+ struct function *old_fun, gimple old_stmt,
+ struct pointer_map_t *map, int default_lp_nr)
+{
+ int old_lp_nr, new_lp_nr;
+ void **slot;
+
+ if (!stmt_could_throw_p (new_stmt))
+ return false;
+
+ old_lp_nr = lookup_stmt_eh_lp_fn (old_fun, old_stmt);
+ if (old_lp_nr == 0)
+ {
+ if (default_lp_nr == 0)
+ return false;
+ new_lp_nr = default_lp_nr;
+ }
+ else if (old_lp_nr > 0)
+ {
+ eh_landing_pad old_lp, new_lp;
+
+ old_lp = VEC_index (eh_landing_pad, old_fun->eh->lp_array, old_lp_nr);
+ slot = pointer_map_contains (map, old_lp);
+ new_lp = (eh_landing_pad) *slot;
+ new_lp_nr = new_lp->index;
+ }
+ else
+ {
+ eh_region old_r, new_r;
+
+ old_r = VEC_index (eh_region, old_fun->eh->region_array, -old_lp_nr);
+ slot = pointer_map_contains (map, old_r);
+ new_r = (eh_region) *slot;
+ new_lp_nr = -new_r->index;
+ }
+
+ add_stmt_to_eh_lp_fn (new_fun, new_stmt, new_lp_nr);
+ return true;
+}
+
+/* Similar, but both OLD_STMT and NEW_STMT are within the current function,
+ and thus no remapping is required. */
+
+bool
+maybe_duplicate_eh_stmt (gimple new_stmt, gimple old_stmt)
+{
+ int lp_nr;
+
+ if (!stmt_could_throw_p (new_stmt))
+ return false;
+
+ lp_nr = lookup_stmt_eh_lp (old_stmt);
+ if (lp_nr == 0)
+ return false;
+
+ add_stmt_to_eh_lp (new_stmt, lp_nr);
+ return true;
+}
+\f
/* Returns TRUE if oneh and twoh are exception handlers (gimple_try_cleanup of
GIMPLE_TRY) that are similar enough to be considered the same. Currently
this only handles handlers consisting of a single call, as that's the
|| gimple_call_lhs (twos)
|| gimple_call_chain (ones)
|| gimple_call_chain (twos)
- || !operand_equal_p (gimple_call_fn (ones), gimple_call_fn (twos), 0)
+ || !gimple_call_same_target_p (ones, twos)
|| gimple_call_num_args (ones) != gimple_call_num_args (twos))
return false;
for (ai = 0; ai < gimple_call_num_args (ones); ++ai)
if (!operand_equal_p (gimple_call_arg (ones, ai),
- gimple_call_arg (twos, ai), 0))
+ gimple_call_arg (twos, ai), 0))
return false;
return true;
{
gimple oneh;
gimple_stmt_iterator gsi;
+ gimple_seq cleanup;
- gsi = gsi_start (gimple_try_cleanup (one));
+ cleanup = gimple_try_cleanup (one);
+ gsi = gsi_start (cleanup);
if (!gsi_one_before_end_p (gsi))
return;
case GIMPLE_EH_FILTER:
refactor_eh_r (gimple_eh_filter_failure (one));
break;
+ case GIMPLE_EH_ELSE:
+ refactor_eh_r (gimple_eh_else_n_body (one));
+ refactor_eh_r (gimple_eh_else_e_body (one));
+ break;
default:
break;
}
return 0;
}
+static bool
+gate_refactor_eh (void)
+{
+ return flag_exceptions != 0;
+}
+
struct gimple_opt_pass pass_refactor_eh =
{
{
GIMPLE_PASS,
"ehopt", /* name */
- NULL, /* gate */
+ gate_refactor_eh, /* gate */
refactor_eh, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_dump_func /* todo_flags_finish */
+ 0 /* todo_flags_finish */
}
};
+\f
+/* At the end of gimple optimization, we can lower RESX. */
-/* Walk statements, see what regions are really references and remove unreachable ones. */
-
-static void
-tree_remove_unreachable_handlers (void)
+static bool
+lower_resx (basic_block bb, gimple stmt, struct pointer_map_t *mnt_map)
{
- sbitmap reachable, contains_stmt;
- VEC(int,heap) * label_to_region;
- basic_block bb;
+ int lp_nr;
+ eh_region src_r, dst_r;
+ gimple_stmt_iterator gsi;
+ gimple x;
+ tree fn, src_nr;
+ bool ret = false;
- label_to_region = label_to_region_map ();
- reachable = sbitmap_alloc (num_eh_regions ());
- sbitmap_zero (reachable);
- contains_stmt = sbitmap_alloc (num_eh_regions ());
- sbitmap_zero (contains_stmt);
+ lp_nr = lookup_stmt_eh_lp (stmt);
+ if (lp_nr != 0)
+ dst_r = get_eh_region_from_lp_number (lp_nr);
+ else
+ dst_r = NULL;
- FOR_EACH_BB (bb)
- {
- gimple_stmt_iterator gsi;
- int region;
- bool has_eh_preds = bb_has_eh_pred (bb);
+ src_r = get_eh_region_from_number (gimple_resx_region (stmt));
+ gsi = gsi_last_bb (bb);
- for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
- {
- gimple stmt = gsi_stmt (gsi);
+ if (src_r == NULL)
+ {
+ /* We can wind up with no source region when pass_cleanup_eh shows
+ that there are no entries into an eh region and deletes it, but
+ then the block that contains the resx isn't removed. This can
+ happen without optimization when the switch statement created by
+ lower_try_finally_switch isn't simplified to remove the eh case.
- if (gimple_code (stmt) == GIMPLE_LABEL && has_eh_preds)
- {
- int uid = LABEL_DECL_UID (gimple_label_label (stmt));
- int region;
+ Resolve this by expanding the resx node to an abort. */
- for (region = VEC_index (int, label_to_region, uid);
- region; region = get_next_region_sharing_label (region))
- SET_BIT (reachable, region);
- }
- if (gimple_code (stmt) == GIMPLE_RESX)
- SET_BIT (reachable,
- VEC_index (eh_region, cfun->eh->region_array,
- gimple_resx_region (stmt))->region_number);
- if ((region = lookup_stmt_eh_region (stmt)) >= 0)
- SET_BIT (contains_stmt, region);
- }
- }
+ fn = builtin_decl_implicit (BUILT_IN_TRAP);
+ x = gimple_build_call (fn, 0);
+ gsi_insert_before (&gsi, x, GSI_SAME_STMT);
- if (dump_file)
- {
- fprintf (dump_file, "Before removal of unreachable regions:\n");
- dump_eh_tree (dump_file, cfun);
- fprintf (dump_file, "Reachable regions: ");
- dump_sbitmap_file (dump_file, reachable);
- fprintf (dump_file, "Regions containing insns: ");
- dump_sbitmap_file (dump_file, contains_stmt);
+ while (EDGE_COUNT (bb->succs) > 0)
+ remove_edge (EDGE_SUCC (bb, 0));
}
-
- remove_unreachable_regions (reachable, contains_stmt);
- sbitmap_free (reachable);
- sbitmap_free (contains_stmt);
- VEC_free (int, heap, label_to_region);
- if (dump_file)
+ else if (dst_r)
{
- fprintf (dump_file, "\n\nAfter removal of unreachable regions:\n");
- dump_eh_tree (dump_file, cfun);
- fprintf (dump_file, "\n\n");
- }
-}
+ /* When we have a destination region, we resolve this by copying
+ the excptr and filter values into place, and changing the edge
+ to immediately after the landing pad. */
+ edge e;
-/* Pattern match emtpy EH receiver looking like:
-
- save_filt.6352_662 = [filter_expr] <<<filter object>>>;
- save_eptr.6351_663 = [exc_ptr_expr] <<<exception object>>>;
- <<<exception object>>> = save_eptr.6351_663;
- <<<filter object>>> = save_filt.6352_662;
- resx 1
+ if (lp_nr < 0)
+ {
+ basic_block new_bb;
+ void **slot;
+ tree lab;
- And various minor variants after DCE or copy propagation.
- */
+ /* We are resuming into a MUST_NOT_CALL region. Expand a call to
+ the failure decl into a new block, if needed. */
+ gcc_assert (dst_r->type == ERT_MUST_NOT_THROW);
-static int
-tree_empty_eh_handler_p (basic_block bb)
-{
- gimple_stmt_iterator gsi;
- int region;
- edge_iterator ei;
- edge e;
- use_operand_p imm_use;
- gimple use_stmt;
- bool found = false;
+ slot = pointer_map_contains (mnt_map, dst_r);
+ if (slot == NULL)
+ {
+ gimple_stmt_iterator gsi2;
- gsi = gsi_last_bb (bb);
+ new_bb = create_empty_bb (bb);
+ if (current_loops)
+ add_bb_to_loop (new_bb, bb->loop_father);
+ lab = gimple_block_label (new_bb);
+ gsi2 = gsi_start_bb (new_bb);
- /* RESX */
- if (gsi_end_p (gsi))
- return 0;
- if (gimple_code (gsi_stmt (gsi)) != GIMPLE_RESX)
- return 0;
- region = gimple_resx_region (gsi_stmt (gsi));
+ fn = dst_r->u.must_not_throw.failure_decl;
+ x = gimple_build_call (fn, 0);
+ gimple_set_location (x, dst_r->u.must_not_throw.failure_loc);
+ gsi_insert_after (&gsi2, x, GSI_CONTINUE_LINKING);
- /* filter_object set. */
- gsi_prev (&gsi);
- if (gsi_end_p (gsi))
- return 0;
- if (gimple_code (gsi_stmt (gsi)) == GIMPLE_ASSIGN)
- {
- tree filter_tmp;
- tree exc_ptr_tmp;
+ slot = pointer_map_insert (mnt_map, dst_r);
+ *slot = lab;
+ }
+ else
+ {
+ lab = (tree) *slot;
+ new_bb = label_to_block (lab);
+ }
- if (TREE_CODE (gimple_assign_lhs (gsi_stmt (gsi))) != FILTER_EXPR)
- return 0;
- filter_tmp = gimple_assign_rhs1 (gsi_stmt (gsi));
+ gcc_assert (EDGE_COUNT (bb->succs) == 0);
+ e = make_edge (bb, new_bb, EDGE_FALLTHRU);
+ e->count = bb->count;
+ e->probability = REG_BR_PROB_BASE;
+ }
+ else
+ {
+ edge_iterator ei;
+ tree dst_nr = build_int_cst (integer_type_node, dst_r->index);
- /* filter_object set. */
- gsi_prev (&gsi);
- if (gsi_end_p (gsi))
- return 0;
- if (gimple_code (gsi_stmt (gsi)) != GIMPLE_ASSIGN)
- return 0;
- if (TREE_CODE (gimple_assign_lhs (gsi_stmt (gsi))) != EXC_PTR_EXPR)
- return 0;
- exc_ptr_tmp = gimple_assign_rhs1 (gsi_stmt (gsi));
+ fn = builtin_decl_implicit (BUILT_IN_EH_COPY_VALUES);
+ src_nr = build_int_cst (integer_type_node, src_r->index);
+ x = gimple_build_call (fn, 2, dst_nr, src_nr);
+ gsi_insert_before (&gsi, x, GSI_SAME_STMT);
- /* exc_ptr get. */
- if (TREE_CODE (exc_ptr_tmp) != EXC_PTR_EXPR)
- {
- gsi_prev (&gsi);
- if (gsi_end_p (gsi))
- return 0;
- if (gimple_code (gsi_stmt (gsi)) != GIMPLE_ASSIGN)
- return 0;
- if (TREE_CODE (gimple_assign_rhs1 (gsi_stmt (gsi))) != EXC_PTR_EXPR)
- return 0;
- if (exc_ptr_tmp != gimple_assign_lhs (gsi_stmt (gsi)))
- return 0;
- if (!single_imm_use (exc_ptr_tmp, &imm_use, &use_stmt))
- return 0;
+ /* Update the flags for the outgoing edge. */
+ e = single_succ_edge (bb);
+ gcc_assert (e->flags & EDGE_EH);
+ e->flags = (e->flags & ~EDGE_EH) | EDGE_FALLTHRU;
+
+ /* If there are no more EH users of the landing pad, delete it. */
+ FOR_EACH_EDGE (e, ei, e->dest->preds)
+ if (e->flags & EDGE_EH)
+ break;
+ if (e == NULL)
+ {
+ eh_landing_pad lp = get_eh_landing_pad_from_number (lp_nr);
+ remove_eh_landing_pad (lp);
+ }
}
- /* filter_object get. */
- if (TREE_CODE (filter_tmp) != FILTER_EXPR)
+ ret = true;
+ }
+ else
+ {
+ tree var;
+
+ /* When we don't have a destination region, this exception escapes
+ up the call chain. We resolve this by generating a call to the
+ _Unwind_Resume library function. */
+
+ /* The ARM EABI redefines _Unwind_Resume as __cxa_end_cleanup
+ with no arguments for C++ and Java. Check for that. */
+ if (src_r->use_cxa_end_cleanup)
+ {
+ fn = builtin_decl_implicit (BUILT_IN_CXA_END_CLEANUP);
+ x = gimple_build_call (fn, 0);
+ gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+ }
+ else
{
- gsi_prev (&gsi);
- if (gsi_end_p (gsi))
- return 0;
- if (gimple_code (gsi_stmt (gsi)) != GIMPLE_ASSIGN)
- return 0;
- if (TREE_CODE (gimple_assign_rhs1 (gsi_stmt (gsi))) != FILTER_EXPR)
- return 0;
- if (filter_tmp != gimple_assign_lhs (gsi_stmt (gsi)))
- return 0;
- if (!single_imm_use (filter_tmp, &imm_use, &use_stmt))
- return 0;
+ fn = builtin_decl_implicit (BUILT_IN_EH_POINTER);
+ src_nr = build_int_cst (integer_type_node, src_r->index);
+ x = gimple_build_call (fn, 1, src_nr);
+ var = create_tmp_var (ptr_type_node, NULL);
+ var = make_ssa_name (var, x);
+ gimple_call_set_lhs (x, var);
+ gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+ fn = builtin_decl_implicit (BUILT_IN_UNWIND_RESUME);
+ x = gimple_build_call (fn, 1, var);
+ gsi_insert_before (&gsi, x, GSI_SAME_STMT);
}
- /* label. */
- gsi_prev (&gsi);
- if (gsi_end_p (gsi))
- return 0;
+ gcc_assert (EDGE_COUNT (bb->succs) == 0);
}
- if (gimple_code (gsi_stmt (gsi)) != GIMPLE_LABEL)
- return 0;
-
- /* Be sure that there is at least on EH region reaching the block directly.
- After EH edge redirection, it is possible that block is reached by one handler
- but resumed by different. */
- FOR_EACH_EDGE (e, ei, bb->preds)
- if ((e->flags & EDGE_EH))
- found = true;
- if (found)
- return region;
- return 0;
-}
-/* Return true if it is possible to remove basic block BB and propagate
- through PHIs.
+ gsi_remove (&gsi, true);
- This means that every PHI in BB has all uses such that they are PHIs
- of basic blocks reachable througt BB and they appears only in use
- reachable by the edge from BB to the block contianing the use.
-
- This is same as in merge-phi code, but in slightly more general setting
- because BB can have multiple successors. */
+ return ret;
+}
-static bool
-all_phis_safe_to_merge (basic_block bb)
+static unsigned
+execute_lower_resx (void)
{
- gimple_stmt_iterator si;
- bool ok = true;
+ basic_block bb;
+ struct pointer_map_t *mnt_map;
+ bool dominance_invalidated = false;
+ bool any_rewritten = false;
+
+ mnt_map = pointer_map_create ();
- for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
+ FOR_EACH_BB (bb)
{
- gimple phi = gsi_stmt (si);
- tree result = gimple_phi_result (phi);
- gimple stmt;
- use_operand_p imm_use;
- imm_use_iterator imm_iter;
+ gimple last = last_stmt (bb);
+ if (last && is_gimple_resx (last))
+ {
+ dominance_invalidated |= lower_resx (bb, last, mnt_map);
+ any_rewritten = true;
+ }
+ }
- /* If the PHI's result is never used, then we can just
- ignore it. */
- if (has_zero_uses (result))
- continue;
- /* We can always rebuild virtuals if needed. */
- if (!is_gimple_reg (result))
- continue;
- FOR_EACH_IMM_USE_STMT (stmt, imm_iter, result)
- {
- if (gimple_code (stmt) != GIMPLE_PHI)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file,
- "PHI result has use in non-PHI statement.\n");
- ok = false;
- BREAK_FROM_IMM_USE_STMT (imm_iter);
- }
- else
- FOR_EACH_IMM_USE_ON_STMT (imm_use, imm_iter)
- {
- edge e;
- e = gimple_phi_arg_edge (stmt, PHI_ARG_INDEX_FROM_USE (imm_use));
- if (e->src != bb)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "PHI has use in PHI not reached from"
- "empty cleanup itself.\n");
- ok = false;
- break;
- }
- }
- if (!ok)
- BREAK_FROM_IMM_USE_STMT (imm_iter);
- }
- if (!ok)
- return false;
+ pointer_map_destroy (mnt_map);
+
+ if (dominance_invalidated)
+ {
+ free_dominance_info (CDI_DOMINATORS);
+ free_dominance_info (CDI_POST_DOMINATORS);
}
- return ok;
-}
-static bool dominance_info_invalidated;
+ return any_rewritten ? TODO_update_ssa_only_virtuals : 0;
+}
-/* Information to pass into make_eh_edge_and_update_phi. */
+static bool
+gate_lower_resx (void)
+{
+ return flag_exceptions != 0;
+}
-struct update_info
+struct gimple_opt_pass pass_lower_resx =
{
- basic_block bb_to_remove, bb;
- edge edge_to_remove;
+ {
+ GIMPLE_PASS,
+ "resx", /* name */
+ gate_lower_resx, /* gate */
+ execute_lower_resx, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_TREE_EH, /* tv_id */
+ PROP_gimple_lcf, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_verify_flow /* todo_flags_finish */
+ }
};
-/* DATA points to update-info structure.
- Like make_eh_edge create EH edge from DATA->bb to basic block containing
- handler of REGION. In addition also update PHI operands by copying
- operands from DATA->bb_to_remove. */
+/* Try to optimize var = {v} {CLOBBER} stmts followed just by
+ external throw. */
static void
-make_eh_edge_and_update_phi (struct eh_region_d *region, void *data)
+optimize_clobbers (basic_block bb)
{
- struct update_info *info = (struct update_info *) data;
- edge e, e2;
- tree lab;
- basic_block src, dst;
- gimple_stmt_iterator si;
-
- lab = get_eh_region_tree_label (region);
-
- src = info->bb;
- dst = label_to_block (lab);
-
- e = find_edge (src, dst);
- if (e)
+ gimple_stmt_iterator gsi = gsi_last_bb (bb);
+ for (gsi_prev (&gsi); !gsi_end_p (gsi); gsi_prev (&gsi))
{
- gcc_assert (e->flags & EDGE_EH);
- e->aux = e;
- return;
- }
- dominance_info_invalidated = true;
- e2 = find_edge (info->bb_to_remove, dst);
- e = make_edge (src, dst, EDGE_EH);
- e->aux = e;
- gcc_assert (e2);
- for (si = gsi_start_phis (dst); !gsi_end_p (si); gsi_next (&si))
- {
- gimple phi = gsi_stmt (si);
- tree use = USE_FROM_PTR (PHI_ARG_DEF_PTR_FROM_EDGE (phi, e2));
- gimple def = (TREE_CODE (use) == SSA_NAME
- ? SSA_NAME_DEF_STMT (use) : NULL);
-
- if (def && gimple_bb (def) == info->bb_to_remove)
- {
- use = USE_FROM_PTR (PHI_ARG_DEF_PTR_FROM_EDGE (def,
- info->edge_to_remove));
- gcc_assert (info->bb_to_remove == info->edge_to_remove->dest);
- def = TREE_CODE (use) == SSA_NAME ? SSA_NAME_DEF_STMT (use) : NULL;
- gcc_assert (!def
- || gimple_bb (def) != info->bb_to_remove
- || !is_gimple_reg (use));
- }
- SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (phi, e), use);
+ gimple stmt = gsi_stmt (gsi);
+ if (is_gimple_debug (stmt))
+ continue;
+ if (!gimple_clobber_p (stmt)
+ || TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME)
+ return;
+ unlink_stmt_vdef (stmt);
+ gsi_remove (&gsi, true);
+ release_defs (stmt);
}
}
-/* Make EH edges corresponding to STMT while updating PHI nodes after removal
- empty cleanup BB_TO_REMOVE joined to BB containing STMT
- by EDGE_TO_REMOVE.
+/* Try to sink var = {v} {CLOBBER} stmts followed just by
+ internal throw to successor BB. */
- Return if EDGE_TO_REMOVE was really removed. It might stay reachable when
- not all EH regions are cleaned up. */
-
-static bool
-update_eh_edges (gimple stmt, basic_block bb_to_remove, edge edge_to_remove)
+static int
+sink_clobbers (basic_block bb)
{
- int region_nr;
- bool is_resx;
- bool inlinable = false;
- struct update_info info;
- edge_iterator ei;
edge e;
- int probability_sum = 0;
- bool removed = false;
-
- info.bb_to_remove = bb_to_remove;
- info.bb = gimple_bb (stmt);
- info.edge_to_remove = edge_to_remove;
+ edge_iterator ei;
+ gimple_stmt_iterator gsi, dgsi;
+ basic_block succbb;
+ bool any_clobbers = false;
+
+ /* Only optimize if BB has a single EH successor and
+ all predecessor edges are EH too. */
+ if (!single_succ_p (bb)
+ || (single_succ_edge (bb)->flags & EDGE_EH) == 0)
+ return 0;
- if (gimple_code (stmt) == GIMPLE_RESX)
+ FOR_EACH_EDGE (e, ei, bb->preds)
{
- region_nr = gimple_resx_region (stmt);
- is_resx = true;
+ if ((e->flags & EDGE_EH) == 0)
+ return 0;
}
- else
+
+ /* And BB contains only CLOBBER stmts before the final
+ RESX. */
+ gsi = gsi_last_bb (bb);
+ for (gsi_prev (&gsi); !gsi_end_p (gsi); gsi_prev (&gsi))
{
- region_nr = lookup_stmt_eh_region (stmt);
- is_resx = false;
- inlinable = inlinable_call_p (stmt);
+ gimple stmt = gsi_stmt (gsi);
+ if (is_gimple_debug (stmt))
+ continue;
+ if (gimple_code (stmt) == GIMPLE_LABEL)
+ break;
+ if (!gimple_clobber_p (stmt)
+ || TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME)
+ return 0;
+ any_clobbers = true;
}
+ if (!any_clobbers)
+ return 0;
- /* First add new edges as neccesary. */
- foreach_reachable_handler (region_nr, is_resx, inlinable,
- make_eh_edge_and_update_phi, &info);
-
- /* And remove edges we didn't marked. */
- for (ei = ei_start (info.bb->succs); (e = ei_safe_edge (ei)); )
+ succbb = single_succ (bb);
+ dgsi = gsi_after_labels (succbb);
+ gsi = gsi_last_bb (bb);
+ for (gsi_prev (&gsi); !gsi_end_p (gsi); gsi_prev (&gsi))
{
- if ((e->flags & EDGE_EH) && !e->aux)
- {
- dominance_info_invalidated = true;
- if (e == edge_to_remove)
- removed = true;
- remove_edge (e);
- }
- else
- {
- e->aux = NULL;
- probability_sum += e->probability;
- ei_next (&ei);
- }
+ gimple stmt = gsi_stmt (gsi);
+ if (is_gimple_debug (stmt))
+ continue;
+ if (gimple_code (stmt) == GIMPLE_LABEL)
+ break;
+ unlink_stmt_vdef (stmt);
+ gsi_remove (&gsi, false);
+ /* Trigger the operand scanner to cause renaming for virtual
+ operands for this statement.
+ ??? Given the simple structure of this code manually
+ figuring out the reaching definition should not be too hard. */
+ if (gimple_vuse (stmt))
+ gimple_set_vuse (stmt, NULL_TREE);
+ gsi_insert_before (&dgsi, stmt, GSI_SAME_STMT);
}
- /* Make CFG profile more consistent assuming that exception will resume to
- first available EH handler. In practice this makes little difference, but
- we get fewer consistency errors in the dumps. */
- if (is_resx && EDGE_COUNT (info.bb->succs) && !probability_sum)
- EDGE_SUCC (info.bb, 0)->probability = REG_BR_PROB_BASE;
- return removed;
+ return TODO_update_ssa_only_virtuals;
}
-/* Look for basic blocks containing empty exception handler and remove them.
- This is similar to jump forwarding, just across EH edges. */
+/* At the end of inlining, we can lower EH_DISPATCH. Return true when
+ we have found some duplicate labels and removed some edges. */
static bool
-cleanup_empty_eh (basic_block bb, VEC(int,heap) * label_to_region)
+lower_eh_dispatch (basic_block src, gimple stmt)
{
- int region;
- gimple_stmt_iterator si;
- edge_iterator ei;
+ gimple_stmt_iterator gsi;
+ int region_nr;
+ eh_region r;
+ tree filter, fn;
+ gimple x;
+ bool redirected = false;
- /* When handler of EH region winds up to be empty, we can safely
- remove it. This leads to inner EH regions to be redirected
- to outer one, if present in function. So we need to rebuild
- EH edges in all sources. */
- if ((region = tree_empty_eh_handler_p (bb))
- && all_phis_safe_to_merge (bb))
- {
- edge e;
- bool found = false, removed_some = false, has_non_eh_preds = false;
- gimple_stmt_iterator gsi;
+ region_nr = gimple_eh_dispatch_region (stmt);
+ r = get_eh_region_from_number (region_nr);
- /* Look for all EH regions sharing label of this block.
- If they are not same as REGION, remove them and replace them
- by outer region of REGION. Also note if REGION itself is one
- of them. */
+ gsi = gsi_last_bb (src);
- for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
- if (gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL)
+ switch (r->type)
+ {
+ case ERT_TRY:
+ {
+ VEC (tree, heap) *labels = NULL;
+ tree default_label = NULL;
+ eh_catch c;
+ edge_iterator ei;
+ edge e;
+ struct pointer_set_t *seen_values = pointer_set_create ();
+
+ /* Collect the labels for a switch. Zero the post_landing_pad
+ field becase we'll no longer have anything keeping these labels
+ in existence and the optimizer will be free to merge these
+ blocks at will. */
+ for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
{
- int uid = LABEL_DECL_UID (gimple_label_label (gsi_stmt (gsi)));
- int r = VEC_index (int, label_to_region, uid);
- int next;
+ tree tp_node, flt_node, lab = c->label;
+ bool have_label = false;
- while (r)
+ c->label = NULL;
+ tp_node = c->type_list;
+ flt_node = c->filter_list;
+
+ if (tp_node == NULL)
+ {
+ default_label = lab;
+ break;
+ }
+ do
{
- next = get_next_region_sharing_label (r);
- if (r == region)
- found = true;
- else
+ /* Filter out duplicate labels that arise when this handler
+ is shadowed by an earlier one. When no labels are
+ attached to the handler anymore, we remove
+ the corresponding edge and then we delete unreachable
+ blocks at the end of this pass. */
+ if (! pointer_set_contains (seen_values, TREE_VALUE (flt_node)))
{
- removed_some = true;
- remove_eh_region_and_replace_by_outer_of (r, region);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Empty EH handler %i removed and "
- "replaced by %i\n", r, region);
+ tree t = build_case_label (TREE_VALUE (flt_node),
+ NULL, lab);
+ VEC_safe_push (tree, heap, labels, t);
+ pointer_set_insert (seen_values, TREE_VALUE (flt_node));
+ have_label = true;
}
- r = next;
+
+ tp_node = TREE_CHAIN (tp_node);
+ flt_node = TREE_CHAIN (flt_node);
+ }
+ while (tp_node);
+ if (! have_label)
+ {
+ remove_edge (find_edge (src, label_to_block (lab)));
+ redirected = true;
}
}
+
+ /* Clean up the edge flags. */
+ FOR_EACH_EDGE (e, ei, src->succs)
+ {
+ if (e->flags & EDGE_FALLTHRU)
+ {
+ /* If there was no catch-all, use the fallthru edge. */
+ if (default_label == NULL)
+ default_label = gimple_block_label (e->dest);
+ e->flags &= ~EDGE_FALLTHRU;
+ }
+ }
+ gcc_assert (default_label != NULL);
+
+ /* Don't generate a switch if there's only a default case.
+ This is common in the form of try { A; } catch (...) { B; }. */
+ if (labels == NULL)
+ {
+ e = single_succ_edge (src);
+ e->flags |= EDGE_FALLTHRU;
+ }
else
- break;
+ {
+ fn = builtin_decl_implicit (BUILT_IN_EH_FILTER);
+ x = gimple_build_call (fn, 1, build_int_cst (integer_type_node,
+ region_nr));
+ filter = create_tmp_var (TREE_TYPE (TREE_TYPE (fn)), NULL);
+ filter = make_ssa_name (filter, x);
+ gimple_call_set_lhs (x, filter);
+ gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+ /* Turn the default label into a default case. */
+ default_label = build_case_label (NULL, NULL, default_label);
+ sort_case_labels (labels);
+
+ x = gimple_build_switch (filter, default_label, labels);
+ gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+ VEC_free (tree, heap, labels);
+ }
+ pointer_set_destroy (seen_values);
+ }
+ break;
+
+ case ERT_ALLOWED_EXCEPTIONS:
+ {
+ edge b_e = BRANCH_EDGE (src);
+ edge f_e = FALLTHRU_EDGE (src);
+
+ fn = builtin_decl_implicit (BUILT_IN_EH_FILTER);
+ x = gimple_build_call (fn, 1, build_int_cst (integer_type_node,
+ region_nr));
+ filter = create_tmp_var (TREE_TYPE (TREE_TYPE (fn)), NULL);
+ filter = make_ssa_name (filter, x);
+ gimple_call_set_lhs (x, filter);
+ gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+ r->u.allowed.label = NULL;
+ x = gimple_build_cond (EQ_EXPR, filter,
+ build_int_cst (TREE_TYPE (filter),
+ r->u.allowed.filter),
+ NULL_TREE, NULL_TREE);
+ gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+ b_e->flags = b_e->flags | EDGE_TRUE_VALUE;
+ f_e->flags = (f_e->flags & ~EDGE_FALLTHRU) | EDGE_FALSE_VALUE;
+ }
+ break;
- gcc_assert (found || removed_some);
- FOR_EACH_EDGE (e, ei, bb->preds)
- if (!(e->flags & EDGE_EH))
- has_non_eh_preds = true;
+ default:
+ gcc_unreachable ();
+ }
- /* When block is empty EH cleanup, but it is reachable via non-EH code too,
- we can not remove the region it is resumed via, because doing so will
- lead to redirection of its RESX edges.
+ /* Replace the EH_DISPATCH with the SWITCH or COND generated above. */
+ gsi_remove (&gsi, true);
+ return redirected;
+}
- This case will be handled later after edge forwarding if the EH cleanup
- is really dead. */
+static unsigned
+execute_lower_eh_dispatch (void)
+{
+ basic_block bb;
+ int flags = 0;
+ bool redirected = false;
- if (found && !has_non_eh_preds)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Empty EH handler %i removed.\n", region);
- remove_eh_region (region);
- }
- else if (!removed_some)
- return false;
+ assign_filter_values ();
- for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
+ FOR_EACH_BB (bb)
+ {
+ gimple last = last_stmt (bb);
+ if (last == NULL)
+ continue;
+ if (gimple_code (last) == GIMPLE_EH_DISPATCH)
{
- basic_block src = e->src;
- if (!(e->flags & EDGE_EH))
- {
- ei_next (&ei);
- continue;
- }
- if (stmt_can_throw_internal (last_stmt (src)))
- {
- if (!update_eh_edges (last_stmt (src), bb, e))
- ei_next (&ei);
- }
+ redirected |= lower_eh_dispatch (bb, last);
+ flags |= TODO_update_ssa_only_virtuals;
+ }
+ else if (gimple_code (last) == GIMPLE_RESX)
+ {
+ if (stmt_can_throw_external (last))
+ optimize_clobbers (bb);
else
- remove_edge (e);
+ flags |= sink_clobbers (bb);
}
+ }
- /* Verify that we eliminated all uses of PHI we are going to remove.
- If we didn't, rebuild SSA on affected variable (this is allowed only
- for virtuals). */
- for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
- {
- gimple phi = gsi_stmt (si);
- tree result = gimple_phi_result (phi);
- if (!has_zero_uses (result))
- {
- use_operand_p use_p;
- imm_use_iterator iter;
- gimple stmt;
+ if (redirected)
+ delete_unreachable_blocks ();
+ return flags;
+}
- FOR_EACH_IMM_USE_STMT (stmt, iter, result)
- {
- /* We have use, see if it won't disappear after
- removing BB. */
- if (gimple_bb (stmt) == bb)
- continue;
- if (gimple_code (stmt) == GIMPLE_PHI)
- {
- bool bad = false;
-
- FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
- if (gimple_phi_arg_edge (stmt,
- PHI_ARG_INDEX_FROM_USE (use_p))->src != bb)
- {
- bad = true;
- break;
- }
-
- if (!bad)
- continue;
- }
-
- gcc_assert (!is_gimple_reg (result));
- mark_sym_for_renaming (SSA_NAME_VAR (result));
- /* As we are going to delete this block we will release all
- defs which makes the immediate uses on use stmts invalid.
- Avoid that by replacing all uses with the bare variable
- and updating the stmts. */
- FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
- SET_USE (use_p, SSA_NAME_VAR (result));
- update_stmt (stmt);
- }
- }
- }
- if (!ei_safe_edge (ei_start (bb->preds)))
- delete_basic_block (bb);
- return true;
- }
+static bool
+gate_lower_eh_dispatch (void)
+{
+ return cfun->eh->region_tree != NULL;
+}
+
+struct gimple_opt_pass pass_lower_eh_dispatch =
+{
+ {
+ GIMPLE_PASS,
+ "ehdisp", /* name */
+ gate_lower_eh_dispatch, /* gate */
+ execute_lower_eh_dispatch, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_TREE_EH, /* tv_id */
+ PROP_gimple_lcf, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_verify_flow /* todo_flags_finish */
+ }
+};
+\f
+/* Walk statements, see what regions are really referenced and remove
+ those that are unused. */
+
+static void
+remove_unreachable_handlers (void)
+{
+ sbitmap r_reachable, lp_reachable;
+ eh_region region;
+ eh_landing_pad lp;
+ basic_block bb;
+ int lp_nr, r_nr;
+
+ r_reachable = sbitmap_alloc (VEC_length (eh_region, cfun->eh->region_array));
+ lp_reachable
+ = sbitmap_alloc (VEC_length (eh_landing_pad, cfun->eh->lp_array));
+ sbitmap_zero (r_reachable);
+ sbitmap_zero (lp_reachable);
+
+ FOR_EACH_BB (bb)
+ {
+ gimple_stmt_iterator gsi;
+
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ lp_nr = lookup_stmt_eh_lp (stmt);
+
+ /* Negative LP numbers are MUST_NOT_THROW regions which
+ are not considered BB enders. */
+ if (lp_nr < 0)
+ SET_BIT (r_reachable, -lp_nr);
+
+ /* Positive LP numbers are real landing pads, are are BB enders. */
+ else if (lp_nr > 0)
+ {
+ gcc_assert (gsi_one_before_end_p (gsi));
+ region = get_eh_region_from_lp_number (lp_nr);
+ SET_BIT (r_reachable, region->index);
+ SET_BIT (lp_reachable, lp_nr);
+ }
+
+ /* Avoid removing regions referenced from RESX/EH_DISPATCH. */
+ switch (gimple_code (stmt))
+ {
+ case GIMPLE_RESX:
+ SET_BIT (r_reachable, gimple_resx_region (stmt));
+ break;
+ case GIMPLE_EH_DISPATCH:
+ SET_BIT (r_reachable, gimple_eh_dispatch_region (stmt));
+ break;
+ default:
+ break;
+ }
+ }
+ }
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "Before removal of unreachable regions:\n");
+ dump_eh_tree (dump_file, cfun);
+ fprintf (dump_file, "Reachable regions: ");
+ dump_sbitmap_file (dump_file, r_reachable);
+ fprintf (dump_file, "Reachable landing pads: ");
+ dump_sbitmap_file (dump_file, lp_reachable);
+ }
+
+ for (r_nr = 1;
+ VEC_iterate (eh_region, cfun->eh->region_array, r_nr, region); ++r_nr)
+ if (region && !TEST_BIT (r_reachable, r_nr))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Removing unreachable region %d\n", r_nr);
+ remove_eh_handler (region);
+ }
+
+ for (lp_nr = 1;
+ VEC_iterate (eh_landing_pad, cfun->eh->lp_array, lp_nr, lp); ++lp_nr)
+ if (lp && !TEST_BIT (lp_reachable, lp_nr))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Removing unreachable landing pad %d\n", lp_nr);
+ remove_eh_landing_pad (lp);
+ }
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "\n\nAfter removal of unreachable regions:\n");
+ dump_eh_tree (dump_file, cfun);
+ fprintf (dump_file, "\n\n");
+ }
+
+ sbitmap_free (r_reachable);
+ sbitmap_free (lp_reachable);
+
+#ifdef ENABLE_CHECKING
+ verify_eh_tree (cfun);
+#endif
+}
+
+/* Remove unreachable handlers if any landing pads have been removed after
+ last ehcleanup pass (due to gimple_purge_dead_eh_edges). */
+
+void
+maybe_remove_unreachable_handlers (void)
+{
+ eh_landing_pad lp;
+ int i;
+
+ if (cfun->eh == NULL)
+ return;
+
+ for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i)
+ if (lp && lp->post_landing_pad)
+ {
+ if (label_to_block (lp->post_landing_pad) == NULL)
+ {
+ remove_unreachable_handlers ();
+ return;
+ }
+ }
+}
+
+/* Remove regions that do not have landing pads. This assumes
+ that remove_unreachable_handlers has already been run, and
+ that we've just manipulated the landing pads since then. */
+
+static void
+remove_unreachable_handlers_no_lp (void)
+{
+ eh_region r;
+ int i;
+ sbitmap r_reachable;
+ basic_block bb;
+
+ r_reachable = sbitmap_alloc (VEC_length (eh_region, cfun->eh->region_array));
+ sbitmap_zero (r_reachable);
+
+ FOR_EACH_BB (bb)
+ {
+ gimple stmt = last_stmt (bb);
+ if (stmt)
+ /* Avoid removing regions referenced from RESX/EH_DISPATCH. */
+ switch (gimple_code (stmt))
+ {
+ case GIMPLE_RESX:
+ SET_BIT (r_reachable, gimple_resx_region (stmt));
+ break;
+ case GIMPLE_EH_DISPATCH:
+ SET_BIT (r_reachable, gimple_eh_dispatch_region (stmt));
+ break;
+ default:
+ break;
+ }
+ }
+
+ for (i = 1; VEC_iterate (eh_region, cfun->eh->region_array, i, r); ++i)
+ if (r && r->landing_pads == NULL && r->type != ERT_MUST_NOT_THROW
+ && !TEST_BIT (r_reachable, i))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Removing unreachable region %d\n", i);
+ remove_eh_handler (r);
+ }
+
+ sbitmap_free (r_reachable);
+}
+
+/* Undo critical edge splitting on an EH landing pad. Earlier, we
+ optimisticaly split all sorts of edges, including EH edges. The
+ optimization passes in between may not have needed them; if not,
+ we should undo the split.
+
+ Recognize this case by having one EH edge incoming to the BB and
+ one normal edge outgoing; BB should be empty apart from the
+ post_landing_pad label.
+
+ Note that this is slightly different from the empty handler case
+ handled by cleanup_empty_eh, in that the actual handler may yet
+ have actual code but the landing pad has been separated from the
+ handler. As such, cleanup_empty_eh relies on this transformation
+ having been done first. */
+
+static bool
+unsplit_eh (eh_landing_pad lp)
+{
+ basic_block bb = label_to_block (lp->post_landing_pad);
+ gimple_stmt_iterator gsi;
+ edge e_in, e_out;
+
+ /* Quickly check the edge counts on BB for singularity. */
+ if (EDGE_COUNT (bb->preds) != 1 || EDGE_COUNT (bb->succs) != 1)
+ return false;
+ e_in = EDGE_PRED (bb, 0);
+ e_out = EDGE_SUCC (bb, 0);
+
+ /* Input edge must be EH and output edge must be normal. */
+ if ((e_in->flags & EDGE_EH) == 0 || (e_out->flags & EDGE_EH) != 0)
+ return false;
+
+ /* The block must be empty except for the labels and debug insns. */
+ gsi = gsi_after_labels (bb);
+ if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi)))
+ gsi_next_nondebug (&gsi);
+ if (!gsi_end_p (gsi))
+ return false;
+
+ /* The destination block must not already have a landing pad
+ for a different region. */
+ for (gsi = gsi_start_bb (e_out->dest); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ tree lab;
+ int lp_nr;
+
+ if (gimple_code (stmt) != GIMPLE_LABEL)
+ break;
+ lab = gimple_label_label (stmt);
+ lp_nr = EH_LANDING_PAD_NR (lab);
+ if (lp_nr && get_eh_region_from_lp_number (lp_nr) != lp->region)
+ return false;
+ }
+
+ /* The new destination block must not already be a destination of
+ the source block, lest we merge fallthru and eh edges and get
+ all sorts of confused. */
+ if (find_edge (e_in->src, e_out->dest))
+ return false;
+
+ /* ??? We can get degenerate phis due to cfg cleanups. I would have
+ thought this should have been cleaned up by a phicprop pass, but
+ that doesn't appear to handle virtuals. Propagate by hand. */
+ if (!gimple_seq_empty_p (phi_nodes (bb)))
+ {
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
+ {
+ gimple use_stmt, phi = gsi_stmt (gsi);
+ tree lhs = gimple_phi_result (phi);
+ tree rhs = gimple_phi_arg_def (phi, 0);
+ use_operand_p use_p;
+ imm_use_iterator iter;
+
+ FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
+ {
+ FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+ SET_USE (use_p, rhs);
+ }
+
+ if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
+ SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs) = 1;
+
+ remove_phi_node (&gsi, true);
+ }
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Unsplit EH landing pad %d to block %i.\n",
+ lp->index, e_out->dest->index);
+
+ /* Redirect the edge. Since redirect_eh_edge_1 expects to be moving
+ a successor edge, humor it. But do the real CFG change with the
+ predecessor of E_OUT in order to preserve the ordering of arguments
+ to the PHI nodes in E_OUT->DEST. */
+ redirect_eh_edge_1 (e_in, e_out->dest, false);
+ redirect_edge_pred (e_out, e_in->src);
+ e_out->flags = e_in->flags;
+ e_out->probability = e_in->probability;
+ e_out->count = e_in->count;
+ remove_edge (e_in);
+
+ return true;
+}
+
+/* Examine each landing pad block and see if it matches unsplit_eh. */
+
+static bool
+unsplit_all_eh (void)
+{
+ bool changed = false;
+ eh_landing_pad lp;
+ int i;
+
+ for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i)
+ if (lp)
+ changed |= unsplit_eh (lp);
+
+ return changed;
+}
+
+/* A subroutine of cleanup_empty_eh. Redirect all EH edges incoming
+ to OLD_BB to NEW_BB; return true on success, false on failure.
+
+ OLD_BB_OUT is the edge into NEW_BB from OLD_BB, so if we miss any
+ PHI variables from OLD_BB we can pick them up from OLD_BB_OUT.
+ Virtual PHIs may be deleted and marked for renaming. */
+
+static bool
+cleanup_empty_eh_merge_phis (basic_block new_bb, basic_block old_bb,
+ edge old_bb_out, bool change_region)
+{
+ gimple_stmt_iterator ngsi, ogsi;
+ edge_iterator ei;
+ edge e;
+ bitmap rename_virts;
+ bitmap ophi_handled;
+
+ /* The destination block must not be a regular successor for any
+ of the preds of the landing pad. Thus, avoid turning
+ <..>
+ | \ EH
+ | <..>
+ | /
+ <..>
+ into
+ <..>
+ | | EH
+ <..>
+ which CFG verification would choke on. See PR45172 and PR51089. */
+ FOR_EACH_EDGE (e, ei, old_bb->preds)
+ if (find_edge (e->src, new_bb))
+ return false;
+
+ FOR_EACH_EDGE (e, ei, old_bb->preds)
+ redirect_edge_var_map_clear (e);
+
+ ophi_handled = BITMAP_ALLOC (NULL);
+ rename_virts = BITMAP_ALLOC (NULL);
+
+ /* First, iterate through the PHIs on NEW_BB and set up the edge_var_map
+ for the edges we're going to move. */
+ for (ngsi = gsi_start_phis (new_bb); !gsi_end_p (ngsi); gsi_next (&ngsi))
+ {
+ gimple ophi, nphi = gsi_stmt (ngsi);
+ tree nresult, nop;
+
+ nresult = gimple_phi_result (nphi);
+ nop = gimple_phi_arg_def (nphi, old_bb_out->dest_idx);
+
+ /* Find the corresponding PHI in OLD_BB so we can forward-propagate
+ the source ssa_name. */
+ ophi = NULL;
+ for (ogsi = gsi_start_phis (old_bb); !gsi_end_p (ogsi); gsi_next (&ogsi))
+ {
+ ophi = gsi_stmt (ogsi);
+ if (gimple_phi_result (ophi) == nop)
+ break;
+ ophi = NULL;
+ }
+
+ /* If we did find the corresponding PHI, copy those inputs. */
+ if (ophi)
+ {
+ /* If NOP is used somewhere else beyond phis in new_bb, give up. */
+ if (!has_single_use (nop))
+ {
+ imm_use_iterator imm_iter;
+ use_operand_p use_p;
+
+ FOR_EACH_IMM_USE_FAST (use_p, imm_iter, nop)
+ {
+ if (!gimple_debug_bind_p (USE_STMT (use_p))
+ && (gimple_code (USE_STMT (use_p)) != GIMPLE_PHI
+ || gimple_bb (USE_STMT (use_p)) != new_bb))
+ goto fail;
+ }
+ }
+ bitmap_set_bit (ophi_handled, SSA_NAME_VERSION (nop));
+ FOR_EACH_EDGE (e, ei, old_bb->preds)
+ {
+ location_t oloc;
+ tree oop;
+
+ if ((e->flags & EDGE_EH) == 0)
+ continue;
+ oop = gimple_phi_arg_def (ophi, e->dest_idx);
+ oloc = gimple_phi_arg_location (ophi, e->dest_idx);
+ redirect_edge_var_map_add (e, nresult, oop, oloc);
+ }
+ }
+ /* If we didn't find the PHI, but it's a VOP, remember to rename
+ it later, assuming all other tests succeed. */
+ else if (virtual_operand_p (nresult))
+ bitmap_set_bit (rename_virts, SSA_NAME_VERSION (nresult));
+ /* If we didn't find the PHI, and it's a real variable, we know
+ from the fact that OLD_BB is tree_empty_eh_handler_p that the
+ variable is unchanged from input to the block and we can simply
+ re-use the input to NEW_BB from the OLD_BB_OUT edge. */
+ else
+ {
+ location_t nloc
+ = gimple_phi_arg_location (nphi, old_bb_out->dest_idx);
+ FOR_EACH_EDGE (e, ei, old_bb->preds)
+ redirect_edge_var_map_add (e, nresult, nop, nloc);
+ }
+ }
+
+ /* Second, verify that all PHIs from OLD_BB have been handled. If not,
+ we don't know what values from the other edges into NEW_BB to use. */
+ for (ogsi = gsi_start_phis (old_bb); !gsi_end_p (ogsi); gsi_next (&ogsi))
+ {
+ gimple ophi = gsi_stmt (ogsi);
+ tree oresult = gimple_phi_result (ophi);
+ if (!bitmap_bit_p (ophi_handled, SSA_NAME_VERSION (oresult)))
+ goto fail;
+ }
+
+ /* At this point we know that the merge will succeed. Remove the PHI
+ nodes for the virtuals that we want to rename. */
+ if (!bitmap_empty_p (rename_virts))
+ {
+ for (ngsi = gsi_start_phis (new_bb); !gsi_end_p (ngsi); )
+ {
+ gimple nphi = gsi_stmt (ngsi);
+ tree nresult = gimple_phi_result (nphi);
+ if (bitmap_bit_p (rename_virts, SSA_NAME_VERSION (nresult)))
+ {
+ mark_virtual_phi_result_for_renaming (nphi);
+ remove_phi_node (&ngsi, true);
+ }
+ else
+ gsi_next (&ngsi);
+ }
+ }
+
+ /* Finally, move the edges and update the PHIs. */
+ for (ei = ei_start (old_bb->preds); (e = ei_safe_edge (ei)); )
+ if (e->flags & EDGE_EH)
+ {
+ /* ??? CFG manipluation routines do not try to update loop
+ form on edge redirection. Do so manually here for now. */
+ /* If we redirect a loop entry or latch edge that will either create
+ a multiple entry loop or rotate the loop. If the loops merge
+ we may have created a loop with multiple latches.
+ All of this isn't easily fixed thus cancel the affected loop
+ and mark the other loop as possibly having multiple latches. */
+ if (current_loops
+ && e->dest == e->dest->loop_father->header)
+ {
+ e->dest->loop_father->header = NULL;
+ e->dest->loop_father->latch = NULL;
+ new_bb->loop_father->latch = NULL;
+ loops_state_set (LOOPS_NEED_FIXUP|LOOPS_MAY_HAVE_MULTIPLE_LATCHES);
+ }
+ redirect_eh_edge_1 (e, new_bb, change_region);
+ redirect_edge_succ (e, new_bb);
+ flush_pending_stmts (e);
+ }
+ else
+ ei_next (&ei);
+
+ BITMAP_FREE (ophi_handled);
+ BITMAP_FREE (rename_virts);
+ return true;
+
+ fail:
+ FOR_EACH_EDGE (e, ei, old_bb->preds)
+ redirect_edge_var_map_clear (e);
+ BITMAP_FREE (ophi_handled);
+ BITMAP_FREE (rename_virts);
return false;
}
+/* A subroutine of cleanup_empty_eh. Move a landing pad LP from its
+ old region to NEW_REGION at BB. */
+
+static void
+cleanup_empty_eh_move_lp (basic_block bb, edge e_out,
+ eh_landing_pad lp, eh_region new_region)
+{
+ gimple_stmt_iterator gsi;
+ eh_landing_pad *pp;
+
+ for (pp = &lp->region->landing_pads; *pp != lp; pp = &(*pp)->next_lp)
+ continue;
+ *pp = lp->next_lp;
+
+ lp->region = new_region;
+ lp->next_lp = new_region->landing_pads;
+ new_region->landing_pads = lp;
+
+ /* Delete the RESX that was matched within the empty handler block. */
+ gsi = gsi_last_bb (bb);
+ unlink_stmt_vdef (gsi_stmt (gsi));
+ gsi_remove (&gsi, true);
+
+ /* Clean up E_OUT for the fallthru. */
+ e_out->flags = (e_out->flags & ~EDGE_EH) | EDGE_FALLTHRU;
+ e_out->probability = REG_BR_PROB_BASE;
+}
+
+/* A subroutine of cleanup_empty_eh. Handle more complex cases of
+ unsplitting than unsplit_eh was prepared to handle, e.g. when
+ multiple incoming edges and phis are involved. */
+
+static bool
+cleanup_empty_eh_unsplit (basic_block bb, edge e_out, eh_landing_pad lp)
+{
+ gimple_stmt_iterator gsi;
+ tree lab;
+
+ /* We really ought not have totally lost everything following
+ a landing pad label. Given that BB is empty, there had better
+ be a successor. */
+ gcc_assert (e_out != NULL);
+
+ /* The destination block must not already have a landing pad
+ for a different region. */
+ lab = NULL;
+ for (gsi = gsi_start_bb (e_out->dest); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ int lp_nr;
+
+ if (gimple_code (stmt) != GIMPLE_LABEL)
+ break;
+ lab = gimple_label_label (stmt);
+ lp_nr = EH_LANDING_PAD_NR (lab);
+ if (lp_nr && get_eh_region_from_lp_number (lp_nr) != lp->region)
+ return false;
+ }
+
+ /* Attempt to move the PHIs into the successor block. */
+ if (cleanup_empty_eh_merge_phis (e_out->dest, bb, e_out, false))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "Unsplit EH landing pad %d to block %i "
+ "(via cleanup_empty_eh).\n",
+ lp->index, e_out->dest->index);
+ return true;
+ }
+
+ return false;
+}
+
+/* Return true if edge E_FIRST is part of an empty infinite loop
+ or leads to such a loop through a series of single successor
+ empty bbs. */
+
+static bool
+infinite_empty_loop_p (edge e_first)
+{
+ bool inf_loop = false;
+ edge e;
+
+ if (e_first->dest == e_first->src)
+ return true;
+
+ e_first->src->aux = (void *) 1;
+ for (e = e_first; single_succ_p (e->dest); e = single_succ_edge (e->dest))
+ {
+ gimple_stmt_iterator gsi;
+ if (e->dest->aux)
+ {
+ inf_loop = true;
+ break;
+ }
+ e->dest->aux = (void *) 1;
+ gsi = gsi_after_labels (e->dest);
+ if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi)))
+ gsi_next_nondebug (&gsi);
+ if (!gsi_end_p (gsi))
+ break;
+ }
+ e_first->src->aux = NULL;
+ for (e = e_first; e->dest->aux; e = single_succ_edge (e->dest))
+ e->dest->aux = NULL;
+
+ return inf_loop;
+}
+
+/* Examine the block associated with LP to determine if it's an empty
+ handler for its EH region. If so, attempt to redirect EH edges to
+ an outer region. Return true the CFG was updated in any way. This
+ is similar to jump forwarding, just across EH edges. */
+
+static bool
+cleanup_empty_eh (eh_landing_pad lp)
+{
+ basic_block bb = label_to_block (lp->post_landing_pad);
+ gimple_stmt_iterator gsi;
+ gimple resx;
+ eh_region new_region;
+ edge_iterator ei;
+ edge e, e_out;
+ bool has_non_eh_pred;
+ bool ret = false;
+ int new_lp_nr;
+
+ /* There can be zero or one edges out of BB. This is the quickest test. */
+ switch (EDGE_COUNT (bb->succs))
+ {
+ case 0:
+ e_out = NULL;
+ break;
+ case 1:
+ e_out = EDGE_SUCC (bb, 0);
+ break;
+ default:
+ return false;
+ }
+
+ resx = last_stmt (bb);
+ if (resx && is_gimple_resx (resx))
+ {
+ if (stmt_can_throw_external (resx))
+ optimize_clobbers (bb);
+ else if (sink_clobbers (bb))
+ ret = true;
+ }
+
+ gsi = gsi_after_labels (bb);
+
+ /* Make sure to skip debug statements. */
+ if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi)))
+ gsi_next_nondebug (&gsi);
+
+ /* If the block is totally empty, look for more unsplitting cases. */
+ if (gsi_end_p (gsi))
+ {
+ /* For the degenerate case of an infinite loop bail out. */
+ if (infinite_empty_loop_p (e_out))
+ return ret;
+
+ return ret | cleanup_empty_eh_unsplit (bb, e_out, lp);
+ }
+
+ /* The block should consist only of a single RESX statement, modulo a
+ preceding call to __builtin_stack_restore if there is no outgoing
+ edge, since the call can be eliminated in this case. */
+ resx = gsi_stmt (gsi);
+ if (!e_out && gimple_call_builtin_p (resx, BUILT_IN_STACK_RESTORE))
+ {
+ gsi_next (&gsi);
+ resx = gsi_stmt (gsi);
+ }
+ if (!is_gimple_resx (resx))
+ return ret;
+ gcc_assert (gsi_one_before_end_p (gsi));
+
+ /* Determine if there are non-EH edges, or resx edges into the handler. */
+ has_non_eh_pred = false;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ if (!(e->flags & EDGE_EH))
+ has_non_eh_pred = true;
+
+ /* Find the handler that's outer of the empty handler by looking at
+ where the RESX instruction was vectored. */
+ new_lp_nr = lookup_stmt_eh_lp (resx);
+ new_region = get_eh_region_from_lp_number (new_lp_nr);
+
+ /* If there's no destination region within the current function,
+ redirection is trivial via removing the throwing statements from
+ the EH region, removing the EH edges, and allowing the block
+ to go unreachable. */
+ if (new_region == NULL)
+ {
+ gcc_assert (e_out == NULL);
+ for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
+ if (e->flags & EDGE_EH)
+ {
+ gimple stmt = last_stmt (e->src);
+ remove_stmt_from_eh_lp (stmt);
+ remove_edge (e);
+ }
+ else
+ ei_next (&ei);
+ goto succeed;
+ }
+
+ /* If the destination region is a MUST_NOT_THROW, allow the runtime
+ to handle the abort and allow the blocks to go unreachable. */
+ if (new_region->type == ERT_MUST_NOT_THROW)
+ {
+ for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
+ if (e->flags & EDGE_EH)
+ {
+ gimple stmt = last_stmt (e->src);
+ remove_stmt_from_eh_lp (stmt);
+ add_stmt_to_eh_lp (stmt, new_lp_nr);
+ remove_edge (e);
+ }
+ else
+ ei_next (&ei);
+ goto succeed;
+ }
+
+ /* Try to redirect the EH edges and merge the PHIs into the destination
+ landing pad block. If the merge succeeds, we'll already have redirected
+ all the EH edges. The handler itself will go unreachable if there were
+ no normal edges. */
+ if (cleanup_empty_eh_merge_phis (e_out->dest, bb, e_out, true))
+ goto succeed;
+
+ /* Finally, if all input edges are EH edges, then we can (potentially)
+ reduce the number of transfers from the runtime by moving the landing
+ pad from the original region to the new region. This is a win when
+ we remove the last CLEANUP region along a particular exception
+ propagation path. Since nothing changes except for the region with
+ which the landing pad is associated, the PHI nodes do not need to be
+ adjusted at all. */
+ if (!has_non_eh_pred)
+ {
+ cleanup_empty_eh_move_lp (bb, e_out, lp, new_region);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Empty EH handler %i moved to EH region %i.\n",
+ lp->index, new_region->index);
+
+ /* ??? The CFG didn't change, but we may have rendered the
+ old EH region unreachable. Trigger a cleanup there. */
+ return true;
+ }
+
+ return ret;
+
+ succeed:
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Empty EH handler %i removed.\n", lp->index);
+ remove_eh_landing_pad (lp);
+ return true;
+}
+
+/* Do a post-order traversal of the EH region tree. Examine each
+ post_landing_pad block and see if we can eliminate it as empty. */
+
+static bool
+cleanup_all_empty_eh (void)
+{
+ bool changed = false;
+ eh_landing_pad lp;
+ int i;
+
+ for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i)
+ if (lp)
+ changed |= cleanup_empty_eh (lp);
+
+ return changed;
+}
/* Perform cleanups and lowering of exception handling
1) cleanups regions with handlers doing nothing are optimized out
3) Info about regions that are containing instructions, and regions
reachable via local EH edges is collected
4) Eh tree is pruned for regions no longer neccesary.
- */
+
+ TODO: Push MUST_NOT_THROW regions to the root of the EH tree.
+ Unify those that have the same failure decl and locus.
+*/
static unsigned int
-cleanup_eh (void)
+execute_cleanup_eh_1 (void)
{
- bool changed = false;
- basic_block bb;
- VEC(int,heap) * label_to_region;
- int i;
+ /* Do this first: unsplit_all_eh and cleanup_all_empty_eh can die
+ looking up unreachable landing pads. */
+ remove_unreachable_handlers ();
- if (!cfun->eh)
- return 0;
- if (dump_file)
+ /* Watch out for the region tree vanishing due to all unreachable. */
+ if (cfun->eh->region_tree && optimize)
{
- fprintf (dump_file, "Before cleanups:\n");
- dump_eh_tree (dump_file, cfun);
- }
+ bool changed = false;
- if (optimize)
- {
- label_to_region = label_to_region_map ();
- dominance_info_invalidated = false;
- /* We cannot use FOR_EACH_BB, since the basic blocks may get removed. */
- for (i = NUM_FIXED_BLOCKS; i < last_basic_block; i++)
- {
- bb = BASIC_BLOCK (i);
- if (bb)
- changed |= cleanup_empty_eh (bb, label_to_region);
- }
- VEC_free (int, heap, label_to_region);
- if (dominance_info_invalidated)
+ changed |= unsplit_all_eh ();
+ changed |= cleanup_all_empty_eh ();
+
+ if (changed)
{
free_dominance_info (CDI_DOMINATORS);
free_dominance_info (CDI_POST_DOMINATORS);
- }
- /* Removing contained cleanup can render MUST_NOT_THROW regions empty. */
- if (changed)
- delete_unreachable_blocks ();
- }
+ /* We delayed all basic block deletion, as we may have performed
+ cleanups on EH edges while non-EH edges were still present. */
+ delete_unreachable_blocks ();
- tree_remove_unreachable_handlers ();
- if (dump_file)
- {
- fprintf (dump_file, "After cleanups:\n");
- dump_eh_tree (dump_file, cfun);
+ /* We manipulated the landing pads. Remove any region that no
+ longer has a landing pad. */
+ remove_unreachable_handlers_no_lp ();
+
+ return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals;
+ }
}
- return (changed ? TODO_cleanup_cfg | TODO_update_ssa : 0);
+ return 0;
+}
+
+static unsigned int
+execute_cleanup_eh (void)
+{
+ int ret = execute_cleanup_eh_1 ();
+
+ /* If the function no longer needs an EH personality routine
+ clear it. This exposes cross-language inlining opportunities
+ and avoids references to a never defined personality routine. */
+ if (DECL_FUNCTION_PERSONALITY (current_function_decl)
+ && function_needs_eh_personality (cfun) != eh_personality_lang)
+ DECL_FUNCTION_PERSONALITY (current_function_decl) = NULL_TREE;
+
+ return ret;
+}
+
+static bool
+gate_cleanup_eh (void)
+{
+ return cfun->eh != NULL && cfun->eh->region_tree != NULL;
}
struct gimple_opt_pass pass_cleanup_eh = {
{
GIMPLE_PASS,
"ehcleanup", /* name */
- NULL, /* gate */
- cleanup_eh, /* execute */
+ gate_cleanup_eh, /* gate */
+ execute_cleanup_eh, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_dump_func /* todo_flags_finish */
+ 0 /* todo_flags_finish */
}
};
+\f
+/* Verify that BB containing STMT as the last statement, has precisely the
+ edge that make_eh_edges would create. */
+
+DEBUG_FUNCTION bool
+verify_eh_edges (gimple stmt)
+{
+ basic_block bb = gimple_bb (stmt);
+ eh_landing_pad lp = NULL;
+ int lp_nr;
+ edge_iterator ei;
+ edge e, eh_edge;
+
+ lp_nr = lookup_stmt_eh_lp (stmt);
+ if (lp_nr > 0)
+ lp = get_eh_landing_pad_from_number (lp_nr);
+
+ eh_edge = NULL;
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ {
+ if (e->flags & EDGE_EH)
+ {
+ if (eh_edge)
+ {
+ error ("BB %i has multiple EH edges", bb->index);
+ return true;
+ }
+ else
+ eh_edge = e;
+ }
+ }
+
+ if (lp == NULL)
+ {
+ if (eh_edge)
+ {
+ error ("BB %i can not throw but has an EH edge", bb->index);
+ return true;
+ }
+ return false;
+ }
+
+ if (!stmt_could_throw_p (stmt))
+ {
+ error ("BB %i last statement has incorrectly set lp", bb->index);
+ return true;
+ }
+
+ if (eh_edge == NULL)
+ {
+ error ("BB %i is missing an EH edge", bb->index);
+ return true;
+ }
+
+ if (eh_edge->dest != label_to_block (lp->post_landing_pad))
+ {
+ error ("Incorrect EH edge %i->%i", bb->index, eh_edge->dest->index);
+ return true;
+ }
+
+ return false;
+}
+
+/* Similarly, but handle GIMPLE_EH_DISPATCH specifically. */
+
+DEBUG_FUNCTION bool
+verify_eh_dispatch_edge (gimple stmt)
+{
+ eh_region r;
+ eh_catch c;
+ basic_block src, dst;
+ bool want_fallthru = true;
+ edge_iterator ei;
+ edge e, fall_edge;
+
+ r = get_eh_region_from_number (gimple_eh_dispatch_region (stmt));
+ src = gimple_bb (stmt);
+
+ FOR_EACH_EDGE (e, ei, src->succs)
+ gcc_assert (e->aux == NULL);
+
+ switch (r->type)
+ {
+ case ERT_TRY:
+ for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
+ {
+ dst = label_to_block (c->label);
+ e = find_edge (src, dst);
+ if (e == NULL)
+ {
+ error ("BB %i is missing an edge", src->index);
+ return true;
+ }
+ e->aux = (void *)e;
+
+ /* A catch-all handler doesn't have a fallthru. */
+ if (c->type_list == NULL)
+ {
+ want_fallthru = false;
+ break;
+ }
+ }
+ break;
+
+ case ERT_ALLOWED_EXCEPTIONS:
+ dst = label_to_block (r->u.allowed.label);
+ e = find_edge (src, dst);
+ if (e == NULL)
+ {
+ error ("BB %i is missing an edge", src->index);
+ return true;
+ }
+ e->aux = (void *)e;
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+
+ fall_edge = NULL;
+ FOR_EACH_EDGE (e, ei, src->succs)
+ {
+ if (e->flags & EDGE_FALLTHRU)
+ {
+ if (fall_edge != NULL)
+ {
+ error ("BB %i too many fallthru edges", src->index);
+ return true;
+ }
+ fall_edge = e;
+ }
+ else if (e->aux)
+ e->aux = NULL;
+ else
+ {
+ error ("BB %i has incorrect edge", src->index);
+ return true;
+ }
+ }
+ if ((fall_edge != NULL) ^ want_fallthru)
+ {
+ error ("BB %i has incorrect fallthru edge", src->index);
+ return true;
+ }
+
+ return false;
+}