[ASTImporter] Fix lexical DC for templated decls; support VarTemplatePartialSpecDecl

Also minor refactoring in related functions was done.

Differential Revision: https://reviews.llvm.org/D43012

llvm-svn: 325116

2 files changed, 26 insertions, 0 deletions

diff --git a/clang/test/ASTMerge/var-cpp/Inputs/var1.cpp b/clang/test/ASTMerge/var-cpp/Inputs/var1.cpp
new file mode 100644
index 00000000000..e29db9d43fb
--- /dev/null
+++ b/clang/test/ASTMerge/var-cpp/Inputs/var1.cpp
@@ -0,0 +1,17 @@
+
+template <typename T>
+constexpr T my_pi = T(3.1415926535897932385L);  // variable template
+
+template <> constexpr char my_pi<char> = '3';   // variable template specialization
+
+template <typename T>
+struct Wrapper {
+  template <typename U> static constexpr U my_const = U(1);
+   // Variable template partial specialization with member variable.
+  template <typename U> static constexpr U *my_const<const U *> = (U *)(0);
+};
+
+constexpr char a[] = "hello";
+
+template <> template <>
+constexpr const char *Wrapper<float>::my_const<const char *> = a;
diff --git a/clang/test/ASTMerge/var-cpp/test.cpp b/clang/test/ASTMerge/var-cpp/test.cpp
new file mode 100644
index 00000000000..28d38d58124
--- /dev/null
+++ b/clang/test/ASTMerge/var-cpp/test.cpp
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -emit-pch -std=c++17 -o %t.1.ast %S/Inputs/var1.cpp
+// RUN: %clang_cc1 -std=c++17 -ast-merge %t.1.ast -fsyntax-only %s 2>&1
+
+static_assert(my_pi<double> == (double)3.1415926535897932385L);
+static_assert(my_pi<char> == '3');
+
+static_assert(Wrapper<int>::my_const<float> == 1.f);
+static_assert(Wrapper<char>::my_const<const float *> == nullptr);
+static_assert(Wrapper<float>::my_const<const char *> == a);