Commit 0223e4f5 by Joseph Myers Committed by Joseph Myers

re PR c/17855 (modification of function struct return not diagnosed)

	PR c/17855
	* gimplify.c (gimplify_expr): Create a temporary for lvalue
	COND_EXPR and CALL_EXPR.

testsuite:
	* gcc.c-torture/compile/struct-non-lval-1.c,
	gcc.c-torture/compile/struct-non-lval-2.c,
	gcc.c-torture/compile/struct-non-lval-3.c: New tests.

From-SVN: r97352
parent 96ddf8ef
2005-04-01 Joseph S. Myers <joseph@codesourcery.com>
PR c/17855
* gimplify.c (gimplify_expr): Create a temporary for lvalue
COND_EXPR and CALL_EXPR.
2005-03-31 Vladimir Makarov <vmakarov@redhat.com>
PR target/20632
......
......@@ -3810,10 +3810,28 @@ gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
case COND_EXPR:
ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE,
fallback);
/* C99 code may assign to an array in a structure value of a
conditional expression, and this has undefined behavior
only on execution, so create a temporary if an lvalue is
required. */
if (fallback == fb_lvalue)
{
*expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
lang_hooks.mark_addressable (*expr_p);
}
break;
case CALL_EXPR:
ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
/* C99 code may assign to an array in a structure returned
from a function, and this has undefined behavior only on
execution, so create a temporary if an lvalue is
required. */
if (fallback == fb_lvalue)
{
*expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
lang_hooks.mark_addressable (*expr_p);
}
break;
case TREE_LIST:
......
2005-04-01 Joseph S. Myers <joseph@codesourcery.com>
PR c/17855
* gcc.c-torture/compile/struct-non-lval-1.c,
gcc.c-torture/compile/struct-non-lval-2.c,
gcc.c-torture/compile/struct-non-lval-3.c: New tests.
2005-03-31 Janis Johnson <janis187@us.ibm.com>
* gcc.dg/tls/tls.exp: Remove temporary file.
......
/* Bug c/17855. */
struct foo {char x, y, z[2];};
struct foo f();
void bar(int baz)
{
f().z[baz] = 1;
}
/* Bug c/17855, using conditional expression for non-lvalue. */
struct foo {char x, y, z[2];};
struct foo p, q; int r;
void bar(int baz)
{
(r ? p : q).z[baz] = 1;
}
/* Bug c/17855, using assignment for non-lvalue. */
struct foo {char x, y, z[2];};
struct foo p, q;
void bar(int baz)
{
(p = q).z[baz] = 1;
}
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