[pushed] c++: ICE with using and enum [PR100659]

[Jason Merrill via Gcc-patches]

Here the code for 'using enum' is confused by the combination of a
using-decl and an enum that are not from 'using enum'; this CONST_DECL is
from the normal unscoped enum scoping.

Tested x86_64-pc-linux-gnu, applying to trunk.

        PR c++/100659

gcc/cp/ChangeLog:

        * cp-tree.h (CONST_DECL_USING_P): Check for null TREE_TYPE.

gcc/testsuite/ChangeLog:

        * g++.dg/parse/access13.C: New test.
---
 gcc/cp/cp-tree.h                      | 1 +
 gcc/testsuite/g++.dg/parse/access13.C | 7 +++++++
 2 files changed, 8 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/parse/access13.C

diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 860ed795299..aa202715873 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -3553,6 +3553,7 @@ struct GTY(()) lang_decl {
    created by handle_using_decl.  */
 #define CONST_DECL_USING_P(NODE)                       \
   (TREE_CODE (NODE) == CONST_DECL                      \
+   && TREE_TYPE (NODE)                                 \
    && TREE_CODE (TREE_TYPE (NODE)) == ENUMERAL_TYPE    \
    && DECL_CONTEXT (NODE) != TREE_TYPE (NODE))
 
diff --git a/gcc/testsuite/g++.dg/parse/access13.C 
b/gcc/testsuite/g++.dg/parse/access13.C
new file mode 100644
index 00000000000..41463c5dde5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/access13.C
@@ -0,0 +1,7 @@
+// PR c++/100659
+
+template <typename> struct A
+{
+  A::E::V;                    // { dg-warning "access decl" }
+  enum { V };                 // { dg-error "conflicts with a previous decl" }
+};

base-commit: 65f32e5d6bbeb93a7d8d121fd56af6555e16d747
-- 
2.27.0