[MSVC] Handle out-of-line definition of static data member correctly (fix for http://llvm.org/PR21164), by Alexey Frolov

There are 3 cases of defining static const member:

initialized inside the class, not defined outside the class.
initialized inside the class, defined outside the class.
not initialized inside the class, defined outside the class.
Revision r213304 was supposed to fix the linkage problem of case (1), but mistakenly it made case (2) behave the same.
As a result, out-of-line definition of static data member is not handled correctly.
Proposed patch distinguishes between cases (1) and (2) and allows to properly emit static const members under –fms-compatibility option.

This fixes http://llvm.org/PR21164.
Differential Revision: http://reviews.llvm.org/D9850

llvm-svn: 237787

1 files changed, 40 insertions, 23 deletions

diff --git a/clang/test/CodeGenCXX/ms-integer-static-data-members.cpp b/clang/test/CodeGenCXX/ms-integer-static-data-members.cpp
index 4965f731918..5e5b81d4a59 100644
--- a/clang/test/CodeGenCXX/ms-integer-static-data-members.cpp
+++ b/clang/test/CodeGenCXX/ms-integer-static-data-members.cpp
@@ -1,35 +1,52 @@
 // RUN: %clang_cc1 -emit-llvm -triple=i386-pc-win32 -fms-compatibility %s -o - | FileCheck %s
-// RUN: %clang_cc1 -DINLINE_INIT -emit-llvm -triple=i386-pc-win32 -fms-compatibility %s -o - | FileCheck %s --check-prefix=CHECK-INLINE
-// RUN: %clang_cc1 -DREAL_DEFINITION -emit-llvm -triple=i386-pc-win32 -fms-compatibility %s -o - | FileCheck %s --check-prefix=CHECK-OUTOFLINE
-// RUN: %clang_cc1 -DINLINE_INIT -DREAL_DEFINITION -emit-llvm -triple=i386-pc-win32 -fms-compatibility %s -o - | FileCheck %s --check-prefix=CHECK-INLINE
 
 struct S {
-  // For MS ABI, we emit a linkonce_odr definition here, even though it's really just a declaration.
-#ifdef INLINE_INIT
-  static const int x = 5;
-#else
-  static const int x;
-#endif
+  static const int NoInit_Ref;
+  static const int Inline_NotDef_NotRef = 5;
+  static const int Inline_NotDef_Ref = 5;
+  static const int Inline_Def_NotRef = 5;
+  static const int Inline_Def_Ref = 5;
+  static const int OutOfLine_Def_NotRef;
+  static const int OutOfLine_Def_Ref;
 };
 
-const int *f() {
-  return &S::x;
+const int *foo1() {
+  return &S::NoInit_Ref;
 };
 
-#ifdef REAL_DEFINITION
-#ifdef INLINE_INIT
-const int S::x;
-#else
-const int S::x = 5;
-#endif
-#endif
+const int *foo2() {
+  return &S::Inline_NotDef_Ref;
+};
+
+const int *foo3() {
+  return &S::Inline_Def_Ref;
+};
 
+const int *foo4() {
+    return &S::OutOfLine_Def_Ref;
+};
 
-// Inline initialization.
-// CHECK-INLINE: @"\01?x@S@@2HB" = linkonce_odr constant i32 5, comdat, align 4
+const int S::Inline_Def_NotRef;
+const int S::Inline_Def_Ref;
+const int S::OutOfLine_Def_NotRef = 5;
+const int S::OutOfLine_Def_Ref = 5;
 
-// Out-of-line initialization.
-// CHECK-OUTOFLINE: @"\01?x@S@@2HB" = constant i32 5, align 4
 
 // No initialization.
-// CHECK: @"\01?x@S@@2HB" = external constant i32
+// CHECK-DAG: @"\01?NoInit_Ref@S@@2HB" = external constant i32
+
+// Inline initialization, no real definiton, not referenced.
+// CHECK-NOT: @"\01?Inline_NotDef_NotRef@S@@2HB" = {{.*}} constant i32 5
+
+// Inline initialization, no real definiton, referenced.
+// CHECK-DAG: @"\01?Inline_NotDef_Ref@S@@2HB" = linkonce_odr constant i32 5, comdat, align 4
+
+// Inline initialization, real definiton, not referenced.
+// CHECK-DAG: @"\01?Inline_Def_NotRef@S@@2HB" = constant i32 5, align 4
+
+// Inline initialization, real definiton, referenced.
+// CHECK-DAG: @"\01?Inline_Def_Ref@S@@2HB" = constant i32 5, comdat, align 4
+
+// Out-of-line initialization.
+// CHECK-DAG: @"\01?OutOfLine_Def_NotRef@S@@2HB" = constant i32 5, align 4
+// CHECK-DAG: @"\01?OutOfLine_Def_Ref@S@@2HB" = constant i32 5, align 4