Hi!
On the following testcase, we have TYPE_READONLY integer type
before handling the mode attribute and transform it into
a signed char type (without TYPE_READONLY), which causes ICE in the FE,
because it isn't const anymore.
Fixed by making sure we have the same quals as before applying the mode
attribute. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?
2017-02-21 Jakub Jelinek <ja...@redhat.com>
PR c++/79641
* c-attribs.c (handle_mode_attribute): Use build_qualified_type to
preserve quals.
* c-c++-common/pr79641.c: New test.
--- gcc/c-family/c-attribs.c.jj 2017-01-01 12:45:46.000000000 +0100
+++ gcc/c-family/c-attribs.c 2017-02-21 12:38:10.105547005 +0100
@@ -1430,7 +1430,7 @@ handle_mode_attribute (tree *node, tree
return NULL_TREE;
}
- *node = typefm;
+ *node = build_qualified_type (typefm, TYPE_QUALS (type));
}
return NULL_TREE;
--- gcc/testsuite/c-c++-common/pr79641.c.jj 2017-02-21 12:43:24.246466684
+0100
+++ gcc/testsuite/c-c++-common/pr79641.c 2017-02-21 12:43:18.132546096
+0100
@@ -0,0 +1,4 @@
+/* PR c++/79641 */
+/* { dg-do compile } */
+
+const int __attribute__((__mode__ (__QI__))) i = 0;
Jakub
