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PR mudflap/19319, c++/19317

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PR mudflap/19319, c++/19317
        * gimplify.c (gimplify_modify_expr_rhs) [CALL_EXPR]: Make return
        slot explicit.

From-SVN: r95150
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Jason Merrill 2005-02-17 00:37:19 -05:00 committed by Jason Merrill
parent beb5f8072a
commit eff9a5d034
2 changed files with 69 additions and 5 deletions
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11
gcc/ChangeLog
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@ -1,3 +1,9 @@
2005-02-17 Jason Merrill <jason@redhat.com>
PR mudflap/19319, c++/19317
* gimplify.c (gimplify_modify_expr_rhs) [CALL_EXPR]: Make return
slot explicit.
2005-02-17 Gerald Pfeifer <gerald@pfeifer.com>
* doc/install.texi (Specific): Update link for Darwin-specific
@ -287,11 +293,6 @@
2005-02-13 Jason Merrill <jason@redhat.com>
[reverted temporarily]
PR mudflap/19319
* gimplify.c (gimplify_modify_expr_rhs) [CALL_EXPR]: Make return
slot explicit.
PR c++/16405
* fold-const.c (fold_indirect_ref_1): Split out from...
(build_fold_indirect_ref): Here.

63
gcc/gimplify.c
View File

@ -2913,6 +2913,69 @@ gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
ret = GS_UNHANDLED;
break;
case CALL_EXPR:
/* For calls that return in memory, give *to_p as the CALL_EXPR's
return slot so that we don't generate a temporary. */
if (aggregate_value_p (*from_p, *from_p))
{
tree init = *from_p;
tree fn = TREE_OPERAND (init, 0);
tree args = TREE_OPERAND (init, 1);
tree rettype = TREE_TYPE (TREE_TYPE (TREE_TYPE (fn)));
tree arg = *to_p;
tree type;
/* Only use the original target if *to_p isn't already
addressable; if its address escapes, and the called function
uses the NRV optimization, a conforming program could see
*to_p change before the called function returns. This is
c++/19317. */
bool use_temp = !is_gimple_non_addressable (*to_p);
/* A CALL_EXPR with an explicit return slot argument should
never appear on the RHS of a MODIFY_EXPR. */
if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (*from_p))
abort ();
if (use_temp)
{
arg = create_tmp_var (rettype, "ret");
*from_p = arg;
}
type = TREE_TYPE (arg);
/* FIXME: Mark the address as not escaping. */
lang_hooks.mark_addressable (arg);
arg = build1 (ADDR_EXPR, build_pointer_type (type), arg);
/* The return type might have different cv-quals from arg. */
arg = convert (build_pointer_type (rettype), arg);
args = tree_cons (NULL_TREE, arg, args);
init = build3 (CALL_EXPR, rettype, fn, args, NULL_TREE);
CALL_EXPR_HAS_RETURN_SLOT_ADDR (init) = 1;
TREE_USED (init) = 1;
if (use_temp)
{
gimplify_and_add (init, pre_p);
ret = GS_OK;
break;
}
else if (want_value)
{
gimplify_and_add (init, pre_p);
*expr_p = *to_p;
return GS_OK;
}
else
{
*expr_p = init;
return GS_OK;
}
}
else
ret = GS_UNHANDLED;
break;
default:
ret = GS_UNHANDLED;
break;