We ICEd on this invalid testcase because build_array_ref was getting
a decl with an incomplete type as an index, and default_conversion
calls require_complete_type on it - and because it's not complete,
it returns error_mark_node, and then we trip on an assert requiring
it to be an integer type.
Fixed by bailing out if default_conversion returns unusable expr.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2014-10-16 Marek Polacek <pola...@redhat.com>
PR c/63549
* c-typeck.c (build_array_ref): Bail if the index in an incomplete
type.
* gcc.dg/pr63549.c: New test.
diff --git gcc/c/c-typeck.c gcc/c/c-typeck.c
index 5c0697a..1e971c1 100644
--- gcc/c/c-typeck.c
+++ gcc/c/c-typeck.c
@@ -2478,6 +2478,8 @@ build_array_ref (location_t loc, tree array, tree index)
/* Apply default promotions *after* noticing character types. */
index = default_conversion (index);
+ if (index == error_mark_node)
+ return error_mark_node;
gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE);
diff --git gcc/testsuite/gcc.dg/pr63549.c gcc/testsuite/gcc.dg/pr63549.c
index e69de29..c9b1718 100644
--- gcc/testsuite/gcc.dg/pr63549.c
+++ gcc/testsuite/gcc.dg/pr63549.c
@@ -0,0 +1,7 @@
+/* PR c/63549 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+enum E e;
+int a[10];
+int i = a[e]; /* { dg-error "has an incomplete type" } */
Marek
