PR31587: Fix handling of __FUNCSIG__ in C.

Fix crash if __FUNCSIG__ is used in a function without a prototype, and use
"(void)" as parameter list instead of "()" for a function with a no-parameters
prototype, matching MSVC's observed behavior.

llvm-svn: 291484

1 files changed, 23 insertions, 5 deletions

diff --git a/clang/test/CodeGenCXX/funcsig.cpp b/clang/test/CodeGenCXX/funcsig.cpp
index 2a6e641aec9..c064946e92d 100644
--- a/clang/test/CodeGenCXX/funcsig.cpp
+++ b/clang/test/CodeGenCXX/funcsig.cpp
@@ -1,22 +1,39 @@
-// RUN: %clang_cc1 -std=c++11 -triple i686-pc-win32 %s -fms-extensions -fno-rtti -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -std=c++11 -triple i686-pc-win32 %s -fms-extensions -fno-rtti -emit-llvm -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-CXX
+// RUN: %clang_cc1 -x c -triple i686-pc-win32 %s -fms-extensions -fno-rtti -emit-llvm -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-C
 
 // Similar to predefined-expr.cpp, but not as exhaustive, since it's basically
 // equivalent to __PRETTY_FUNCTION__.
 
-extern "C" int printf(const char *, ...);
+#ifdef __cplusplus
+extern "C"
+#endif
+int printf(const char *, ...);
 
-void freeFunc(int *, char) {
+void funcNoProto() {
+  printf("__FUNCSIG__ %s\n\n", __FUNCSIG__);
+}
+// CHECK-C:   @"\01??_C@_0BL@IHLLLCAO@void?5__cdecl?5funcNoProto?$CI?$CJ?$AA@" = linkonce_odr unnamed_addr constant [27 x i8] c"void __cdecl funcNoProto()\00"
+// CHECK-CXX: @"\01??_C@_0BL@IHLLLCAO@void?5__cdecl?5funcNoProto?$CI?$CJ?$AA@" = linkonce_odr unnamed_addr constant [27 x i8] c"void __cdecl funcNoProto()\00"
+
+void funcNoParams(void) {
+  printf("__FUNCSIG__ %s\n\n", __FUNCSIG__);
+}
+// CHECK-C:   @"\01??_C@_0CA@GBIDFNBN@void?5__cdecl?5funcNoParams?$CIvoid?$CJ?$AA@" = linkonce_odr unnamed_addr constant [32 x i8] c"void __cdecl funcNoParams(void)\00"
+// CHECK-CXX: @"\01??_C@_0BM@GDFBOAEE@void?5__cdecl?5funcNoParams?$CI?$CJ?$AA@" = linkonce_odr unnamed_addr constant [28 x i8] c"void __cdecl funcNoParams()\00"
+
+void freeFunc(int *p, char c) {
   printf("__FUNCSIG__ %s\n\n", __FUNCSIG__);
 }
 // CHECK: @"\01??_C@_0CD@KLGMNNL@void?5__cdecl?5freeFunc?$CIint?5?$CK?0?5cha@" = linkonce_odr unnamed_addr constant [{{.*}} x i8] c"void __cdecl freeFunc(int *, char)\00"
 
+#ifdef __cplusplus
 struct TopLevelClass {
   void topLevelMethod(int *, char);
 };
 void TopLevelClass::topLevelMethod(int *, char) {
   printf("__FUNCSIG__ %s\n\n", __FUNCSIG__);
 }
-// CHECK: @"\01??_C@_0DL@OBHNMDP@void?5__thiscall?5TopLevelClass?3?3t@" = linkonce_odr unnamed_addr constant [{{.*}} x i8] c"void __thiscall TopLevelClass::topLevelMethod(int *, char)\00"
+// CHECK-CXX: @"\01??_C@_0DL@OBHNMDP@void?5__thiscall?5TopLevelClass?3?3t@" = linkonce_odr unnamed_addr constant [{{.*}} x i8] c"void __thiscall TopLevelClass::topLevelMethod(int *, char)\00"
 
 namespace NS {
 struct NamespacedClass {
@@ -25,5 +42,6 @@ struct NamespacedClass {
 void NamespacedClass::namespacedMethod(int *, char) {
   printf("__FUNCSIG__ %s\n\n", __FUNCSIG__);
 }
-// CHECK: @"\01??_C@_0ED@PFDKIEBA@void?5__thiscall?5NS?3?3NamespacedCl@" = linkonce_odr unnamed_addr constant [{{.*}} x i8] c"void __thiscall NS::NamespacedClass::namespacedMethod(int *, char)\00"
+// CHECK-CXX: @"\01??_C@_0ED@PFDKIEBA@void?5__thiscall?5NS?3?3NamespacedCl@" = linkonce_odr unnamed_addr constant [{{.*}} x i8] c"void __thiscall NS::NamespacedClass::namespacedMethod(int *, char)\00"
 }
+#endif