Fix PR7402 when it strikes via template instantiation.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@113019 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 24 insertions, 0 deletions

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index e3b6614faa..1c7869fecd 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2274,6 +2274,11 @@ Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
        Inits != InitsEnd; ++Inits) {
     CXXBaseOrMemberInitializer *Init = *Inits;
 
+    // Only instantiate written initializers, let Sema re-construct implicit
+    // ones.
+    if (!Init->isWritten())
+      continue;
+
     SourceLocation LParenLoc, RParenLoc;
     ASTOwningVector<Expr*> NewArgs(*this);
     llvm::SmallVector<SourceLocation, 4> CommaLocs;
diff --git a/test/SemaTemplate/instantiate-anonymous-union.cpp b/test/SemaTemplate/instantiate-anonymous-union.cpp
index 255454b2eb..f2862db6bb 100644
--- a/test/SemaTemplate/instantiate-anonymous-union.cpp
+++ b/test/SemaTemplate/instantiate-anonymous-union.cpp
@@ -47,3 +47,22 @@ namespace PR7088 {
 
   template void f<double>();
 }
+
+// Check for problems related to PR7402 that occur when template instantiation
+// instantiates implicit initializers.
+namespace PR7402 {
+  struct X {
+    union {
+      struct {
+        int x;
+        int y;
+      };
+      int v[2];
+    };
+
+    // Check that this requirement survives instantiation.
+    template <typename T> X(const T& t) : x(t), y(t) {}
+  };
+
+  X x(42.0);
+}