/* 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
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 "timevar.h"
#include "langhooks.h"
#include "ggc.h"
-#include "toplev.h"
+#include "diagnostic-core.h"
#include "gimple.h"
#include "target.h"
gcc_assert (num != 0);
- n = GGC_NEW (struct throw_stmt_node);
+ n = ggc_alloc_throw_stmt_node ();
n->stmt = t;
n->lp_nr = num;
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 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;
gimple x;
/* First check for nothing to do. */
- if (lang_protect_cleanup_actions == NULL)
+ if (lang_hooks.eh_protect_cleanup_actions == NULL)
return;
- protect_cleanup_actions = lang_protect_cleanup_actions ();
+ protect_cleanup_actions = lang_hooks.eh_protect_cleanup_actions ();
if (protect_cleanup_actions == NULL)
return;
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
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;
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)
+ if (this_tf.region)
this_tf.may_throw = eh_region_may_contain_throw (this_tf.region);
if (this_tf.may_throw)
honor_protect_cleanup_actions (state, &this_state, &this_tf);
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 (flag_exceptions)
+ if (flag_exceptions && !cleanup_dead)
{
this_region = gen_eh_region_cleanup (state->cur_region);
this_state.cur_region = this_region;
lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
- if (!eh_region_may_contain_throw (this_region))
+ 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
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 GIMPLE_ASSIGN:
case GIMPLE_COND:
- if (!flag_non_call_exceptions)
+ if (!cfun->can_throw_non_call_exceptions)
return false;
return stmt_could_throw_1_p (stmt);
case GIMPLE_ASM:
- if (!flag_non_call_exceptions)
+ if (!cfun->can_throw_non_call_exceptions)
return false;
return gimple_asm_volatile_p (stmt);
return false;
if (TREE_CODE (t) == MODIFY_EXPR)
{
- if (flag_non_call_exceptions
+ 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;
}
*/
static unsigned int
-execute_cleanup_eh (void)
+execute_cleanup_eh_1 (void)
{
/* Do this first: unsplit_all_eh and cleanup_all_empty_eh can die
looking up unreachable landing pads. */
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)
{
/* Verify that BB containing STMT as the last statement, has precisely the
edge that make_eh_edges would create. */
-bool
+DEBUG_FUNCTION bool
verify_eh_edges (gimple stmt)
{
basic_block bb = gimple_bb (stmt);
/* Similarly, but handle GIMPLE_EH_DISPATCH specifically. */
-bool
+DEBUG_FUNCTION bool
verify_eh_dispatch_edge (gimple stmt)
{
eh_region r;
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