Hi!
On VLAs with register only constraints we ICE, because during gimplification
we try to create temporaries for them and force_constant_size aborts in that
case.
The following patch diagnoses those early, like we diagnose already C++
non-PODs.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2019-11-05 Jakub Jelinek <ja...@redhat.com>
PR inline-asm/92352
* gimplify.c (gimplify_asm_expr): Reject VLA in output or input
operands with non-memory constraints.
* c-c++-common/pr92352.c: New test.
--- gcc/gimplify.c.jj 2019-11-02 10:00:59.595253274 +0100
+++ gcc/gimplify.c 2019-11-05 00:21:01.585958514 +0100
@@ -6235,8 +6235,14 @@ gimplify_asm_expr (tree *expr_p, gimple_
is_inout = false;
}
- /* If we can't make copies, we can only accept memory. */
- if (TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (link))))
+ /* If we can't make copies, we can only accept memory.
+ Similarly for VLAs. */
+ tree outtype = TREE_TYPE (TREE_VALUE (link));
+ if (outtype != error_mark_node
+ && (TREE_ADDRESSABLE (outtype)
+ || !COMPLETE_TYPE_P (outtype)
+ || (!tree_fits_poly_uint64_p (TYPE_SIZE_UNIT (outtype))
+ && max_int_size_in_bytes (outtype))))
{
if (allows_mem)
allows_reg = 0;
@@ -6392,7 +6398,12 @@ gimplify_asm_expr (tree *expr_p, gimple_
oconstraints, &allows_mem, &allows_reg);
/* If we can't make copies, we can only accept memory. */
- if (TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (link))))
+ tree intype = TREE_TYPE (TREE_VALUE (link));
+ if (intype != error_mark_node
+ && (TREE_ADDRESSABLE (intype)
+ || !COMPLETE_TYPE_P (intype)
+ || (!tree_fits_poly_uint64_p (TYPE_SIZE_UNIT (intype))
+ && max_int_size_in_bytes (intype))))
{
if (allows_mem)
allows_reg = 0;
--- gcc/testsuite/c-c++-common/pr92352.c.jj 2019-11-04 14:03:18.725275255
+0100
+++ gcc/testsuite/c-c++-common/pr92352.c 2019-11-04 14:02:55.211629675
+0100
@@ -0,0 +1,15 @@
+/* PR inline-asm/92352 */
+
+void
+foo (int x)
+{
+ int var[x];
+ asm volatile ("" : "+r" (var)); /* { dg-error "impossible constraint in
'asm'" } */
+} /* { dg-error "non-memory output 0 must
stay in memory" "" { target *-*-* } .-1 } */
+
+void
+bar (int x)
+{
+ int var[x];
+ asm volatile ("" : "+m" (var));
+}
Jakub
