re PR c++/51228 (ICE with transparent union)

	PR c++/51228
	* c-common.c (handle_transparent_union_attribute): Check the first
	field if the type is complete.

From-SVN: r182494

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index 78854e2f81b2e491e5b330c2839828defebca593..2b8f32578619d82720c526cfabdda4b8e43171ce 100644 (file)
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,9 @@
+2011-12-19  Jason Merrill  <jason@redhat.com>
+
+       PR c++/51228
+       * c-common.c (handle_transparent_union_attribute): Check the first
+       field if the type is complete.
+
 2011-12-15  Jonathan Wakely  <jwakely.gcc@gmail.com>
 
        PR libstdc++/51365

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 3e50dcf924f8838bfb92bee2ca7a1c93c6edfa2c..0562f2624f3c8ffbead2b44b7161949d917a57d3 100644 (file)
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -6287,13 +6287,27 @@ handle_transparent_union_attribute (tree *node, tree name,
 
   if (TREE_CODE (type) == UNION_TYPE)
     {
-      /* When IN_PLACE is set, leave the check for FIELDS and MODE to
-        the code in finish_struct.  */
+      /* Make sure that the first field will work for a transparent union.
+        If the type isn't complete yet, leave the check to the code in
+        finish_struct.  */
+      if (TYPE_SIZE (type))
+       {
+         tree first = first_field (type);
+         if (first == NULL_TREE
+             || DECL_ARTIFICIAL (first)
+             || TYPE_MODE (type) != DECL_MODE (first))
+           goto ignored;
+       }
+
       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
        {
-         if (TYPE_FIELDS (type) == NULL_TREE
-             || c_dialect_cxx ()
-             || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
+         /* If the type isn't complete yet, setting the flag
+            on a variant wouldn't ever be checked.  */
+         if (!TYPE_SIZE (type))
+           goto ignored;
+
+         /* build_duplicate_type doesn't work for C++.  */
+         if (c_dialect_cxx ())
            goto ignored;
 
          /* A type variant isn't good enough, since we don't a cast

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f74bad768cfe991fcaab76a5f6ed142c2ec8c9d2..70c3315583252b1e13bd8fb62ceb5522569013b5 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-12-19  Jason Merrill  <jason@redhat.com>
+
+       PR c++/51228
+       * c-c++-common/transparent-union-1.c: New.
+
 2011-12-19  Eric Botcazou  <ebotcazou@adacore.com>
 
        PR tree-optimization/51580

diff --git a/gcc/testsuite/c-c++-common/transparent-union-1.c b/gcc/testsuite/c-c++-common/transparent-union-1.c
new file mode 100644 (file)
index 0000000..3fb6e78
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/transparent-union-1.c
@@ -0,0 +1,5 @@
+/* PR c++/51228 */
+
+typedef union {} U __attribute__((transparent_union)); /* { dg-warning "ignored" } */
+
+void foo(U u) {}