Hi!
fold_binary_loc verifies that strlen argument is a pointer, but doesn't
verify what the pointee is.
The following patch just always converts it to the right pointer type
(const char *) and dereferences only that.
Another option would be punt if the pointee (TYPE_MAIN_VARIANT) is not
char_type_node, but then e.g. unsigned_char_type_node or
signed_char_type_node (or maybe char8_t) wouldn't be that bad.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2019-02-12 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/89314
* fold-const.c (fold_binary_loc): Cast strlen argument to
const char * before dereferencing it. Formatting fixes.
* gcc.dg/pr89314.c: New test.
--- gcc/fold-const.c.jj 2019-02-11 18:04:18.000000000 +0100
+++ gcc/fold-const.c 2019-02-12 21:11:21.491388038 +0100
@@ -10740,20 +10740,24 @@ fold_binary_loc (location_t loc, enum tr
strlen(ptr) != 0 => *ptr != 0
Other cases should reduce to one of these two (or a constant)
due to the return value of strlen being unsigned. */
- if (TREE_CODE (arg0) == CALL_EXPR
- && integer_zerop (arg1))
+ if (TREE_CODE (arg0) == CALL_EXPR && integer_zerop (arg1))
{
tree fndecl = get_callee_fndecl (arg0);
if (fndecl
&& fndecl_built_in_p (fndecl, BUILT_IN_STRLEN)
&& call_expr_nargs (arg0) == 1
- && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) ==
POINTER_TYPE)
+ && (TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0)))
+ == POINTER_TYPE))
{
- tree iref = build_fold_indirect_ref_loc (loc,
- CALL_EXPR_ARG (arg0, 0));
+ tree ptrtype
+ = build_pointer_type (build_qualified_type (char_type_node,
+ TYPE_QUAL_CONST));
+ tree ptr = fold_convert_loc (loc, ptrtype,
+ CALL_EXPR_ARG (arg0, 0));
+ tree iref = build_fold_indirect_ref_loc (loc, ptr);
return fold_build2_loc (loc, code, type, iref,
- build_int_cst (TREE_TYPE (iref), 0));
+ build_int_cst (TREE_TYPE (iref), 0));
}
}
--- gcc/testsuite/gcc.dg/pr89314.c.jj 2019-02-12 21:15:11.624589045 +0100
+++ gcc/testsuite/gcc.dg/pr89314.c 2019-02-12 21:14:49.138960233 +0100
@@ -0,0 +1,13 @@
+/* PR tree-optimization/89314 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wbuiltin-declaration-mismatch -Wextra" } */
+
+extern __SIZE_TYPE__ strlen (const float *); /* { dg-warning "mismatch in
argument 1 type of built-in function" } */
+void bar (void);
+
+void
+foo (float *s)
+{
+ if (strlen (s) > 0)
+ bar ();
+}
Jakub
