[MS] Consder constexpr globals to be inline, as in C++17

Summary:
Microsoft seems to do this regardless of the language mode, so we must
also do it in order to be ABI compatible.

Fixes PR36125

Reviewers: thakis

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D47956

llvm-svn: 371642

1 files changed, 26 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/ms-constexpr-static-data-member.cpp b/clang/test/CodeGenCXX/ms-constexpr-static-data-member.cpp
new file mode 100644
index 00000000000..dc2c4862e97
--- /dev/null
+++ b/clang/test/CodeGenCXX/ms-constexpr-static-data-member.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -emit-llvm -triple=x86_64-windows-msvc %s -o - | FileCheck %s
+
+struct Foo { int x, y; };
+
+struct S {
+  // PR36125
+  static constexpr char sdm_char_array[] = "asdf";
+
+  // PR43280
+  static constexpr const char *sdm_char_ptr = "asdf";
+
+  static constexpr Foo sdm_udt{1, 2};
+};
+
+void useptr(const void *p);
+void usethem() {
+  useptr(&S::sdm_char_array);
+  useptr(&S::sdm_char_ptr);
+  useptr(&S::sdm_udt);
+}
+
+// CHECK-DAG: @"?sdm_char_array@S@@2QBDB" = linkonce_odr dso_local constant [5 x i8] c"asdf\00", comdat, align 1
+
+// CHECK-DAG: @"?sdm_char_ptr@S@@2QEBDEB" = linkonce_odr dso_local constant i8* getelementptr inbounds ([5 x i8], [5 x i8]* @"??_C@_04JIHMPGLA@asdf?$AA@", i32 0, i32 0), comdat, align 8
+
+// CHECK-DAG: @"?sdm_udt@S@@2UFoo@@B" = linkonce_odr dso_local constant %struct.Foo { i32 1, i32 2 }, comdat, align 4