From: Richard Smith <richard@metafoo.co.uk>
Date: Sat, 14 Mar 2020 02:29:44 +0000 (-0700)
Subject: PR44992 Don't crash when a defaulted <=> is in a class declared in a
X-Git-Tag: llvmorg-12-init~12095
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=810794ce882850a11baca35aa4ef107ee8ee7f53;p=platform%2Fupstream%2Fllvm.git

PR44992 Don't crash when a defaulted <=> is in a class declared in a
transparent context.

(The same crash would happen if a class template with a friend was
declared in an 'export' block, but there are more issues with that
case.)
---

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 109b649..875eb2b 100755
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2039,7 +2039,7 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(
     // Look only into the namespace where the friend would be declared to
     // find a previous declaration. This is the innermost enclosing namespace,
     // as described in ActOnFriendFunctionDecl.
-    SemaRef.LookupQualifiedName(Previous, DC);
+    SemaRef.LookupQualifiedName(Previous, DC->getRedeclContext());
 
     // In C++, the previous declaration we find might be a tag type
     // (class or enum). In this case, the new declaration will hide the
diff --git a/clang/test/SemaCXX/compare-cxx2a.cpp b/clang/test/SemaCXX/compare-cxx2a.cpp
index 46e38f7..a459554 100644
--- a/clang/test/SemaCXX/compare-cxx2a.cpp
+++ b/clang/test/SemaCXX/compare-cxx2a.cpp
@@ -426,3 +426,9 @@ namespace Vector {
     (void)(v1 <=> v2); // expected-error {{three-way comparison between vectors is not supported}}
   }
 }
+
+namespace PR44992 {
+  extern "C++" struct s {
+    friend auto operator<=>(s const &, s const &) = default;
+  };
+}