On 8/3/21 1:17 AM, Jakub Jelinek wrote:
Hi!
The following testcase ICEs, because nelts is NOP_EXPR around INTEGER_CST
- it is a VLA whose extent folds into a constant - and get_parm_array_spec
has specific INTEGER_CST handling and otherwise strips nops from nelts
and stores it into a TREE_LIST that is later asserted to be a DECL_P
or EXPR_P, where the INTEGER_CST is neither of that.
So, either we can strip nops earlier (needs moving the integral type
check first as STRIP_NOPS can alter that e.g. to pointer or from
pointer to integer) and thus handle as INTEGER_CST even the case
of INTEGER_CST wrapped into casts as this patch does, or we need
to change handle_argspec_attribute's assertion to allow INTEGER_CSTs
as well there.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Or do you prefer to change handle_argspec_attribute ?
I think the bug is in the bound being treated as variable but then
in determining its value to be constant. I expect the following
to be diagnosed again, the same way as in GCC 11:
double foo (double x[!__builtin_copysignf (~2, 3)]);
double foo (double x[]);
Your fix prevents it. So I think the right fix would treat
the bound as constant in this case.
Martin
2021-08-03 Jakub Jelinek <ja...@redhat.com>
PR c/101702
* c-decl.c (get_parm_array_spec): Check for non-integral
type first, then STRIP_NOPS and only afterwards check for
INTEGER_CST.
* gcc.dg/pr101702.c: New test.
--- gcc/c/c-decl.c.jj 2021-07-15 18:50:52.000000000 +0200
+++ gcc/c/c-decl.c 2021-08-02 18:56:35.532045128 +0200
@@ -5842,6 +5842,11 @@ get_parm_array_spec (const struct c_parm
if (pd->u.array.static_p)
spec += 's';
+ if (!INTEGRAL_TYPE_P (TREE_TYPE (nelts)))
+ /* Avoid invalid NELTS. */
+ return attrs;
+
+ STRIP_NOPS (nelts);
if (TREE_CODE (nelts) == INTEGER_CST)
{
/* Skip all constant bounds except the most significant one.
@@ -5859,13 +5864,9 @@ get_parm_array_spec (const struct c_parm
spec += buf;
break;
}
- else if (!INTEGRAL_TYPE_P (TREE_TYPE (nelts)))
- /* Avoid invalid NELTS. */
- return attrs;
/* Each variable VLA bound is represented by a dollar sign. */
spec += "$";
- STRIP_NOPS (nelts);
vbchain = tree_cons (NULL_TREE, nelts, vbchain);
}
--- gcc/testsuite/gcc.dg/pr101702.c.jj 2021-08-02 18:58:24.614534975 +0200
+++ gcc/testsuite/gcc.dg/pr101702.c 2021-08-02 18:57:52.611978024 +0200
@@ -0,0 +1,11 @@
+/* PR c/101702 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+double foo (double x[!__builtin_copysignf (~2, 3)]);
+
+double
+bar (double *x)
+{
+ return foo (x);
+}
Jakub
