Permit redeclarations of a builtin to specify calling convention.

After https://reviews.llvm.org/rL355317 we noticed that quite a decent
amount of code redeclares builtins (memcpy in particular, I believe
reduced from an MSVC header) with a calling convention specified.
This gets particularly troublesome when the user specifies a new
'default' calling convention on the command line.

When looking to add a diagnostic for this case, it was noticed that we
had 3 other diagnostics that differed only slightly.  This patch ALSO
unifies those under a 'select'.  Unfortunately, the order of words in
ONE of these diagnostics was reversed ("'thiscall' calling convention"
vs "calling convention 'thiscall'"), so this patch also standardizes on
the former.

Differential Revision: https://reviews.llvm.org/D59560

Change-Id: I79f99fe7c2301640755ffdd774b46eb44526bb22
llvm-svn: 356663

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -2923,7 +2923,14 @@ def err_cconv_change : Error<
   "function declared '%0' here was previously declared "
   "%select{'%2'|without calling convention}1">;
 def warn_cconv_ignored : Warning<
-  "calling convention %0 ignored for this target">, InGroup<IgnoredAttributes>;
+  "%0 calling convention ignored %select{"
+  // Use CallingConventionIgnoredReason Enum to specify these.
+  "for this target"
+  "|on variadic function"
+  "|on constructor/destructor"
+  "|on builtin function"
+  "}1">,
+  InGroup<IgnoredAttributes>;
 def err_cconv_knr : Error<
   "function with no prototype cannot use the %0 calling convention">;
 def warn_cconv_knr : Warning<
@@ -2931,12 +2938,6 @@ def warn_cconv_knr : Warning<
   InGroup<DiagGroup<"missing-prototype-for-cc">>;
 def err_cconv_varargs : Error<
   "variadic function cannot use %0 calling convention">;
-def warn_cconv_varargs : Warning<
-  "%0 calling convention ignored on variadic function">,
-  InGroup<IgnoredAttributes>;
-def warn_cconv_structors : Warning<
-  "%0 calling convention ignored on constructor/destructor">,
-  InGroup<IgnoredAttributes>;
 def err_regparm_mismatch : Error<"function declared with regparm(%0) "
   "attribute was previously declared "
   "%plural{0:without the regparm|:with the regparm(%1)}1 attribute">;

clang/include/clang/Sema/Sema.h

@@ -11017,6 +11017,15 @@ public:
       Expr *E,
       llvm::function_ref<void(Expr *, RecordDecl *, FieldDecl *, CharUnits)>
           Action);
+
+  /// Describes the reason a calling convention specification was ignored, used
+  /// for diagnostics.
+  enum class CallingConventionIgnoredReason {
+    ForThisTarget = 0,
+    VariadicFunction,
+    ConstructorDestructor,
+    BuiltinFunction
+  };
 };
 
 /// RAII object that enters a new expression evaluation context.

clang/lib/Sema/SemaDecl.cpp

@@ -3136,6 +3136,15 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD,
       // there but not here.
       NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
       RequiresAdjustment = true;
+    } else if (New->getBuiltinID()) {
+      // Calling Conventions on a Builtin aren't really useful and setting a
+      // default calling convention and cdecl'ing some builtin redeclarations is
+      // common, so warn and ignore the calling convention on the redeclaration.
+      Diag(New->getLocation(), diag::warn_cconv_ignored)
+          << FunctionType::getNameForCallConv(NewTypeInfo.getCC())
+          << (int)CallingConventionIgnoredReason::BuiltinFunction;
+      NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
+      RequiresAdjustment = true;
     } else {
       // Calling conventions aren't compatible, so complain.
       bool FirstCCExplicit = getCallingConvAttributedType(First->getType());

clang/lib/Sema/SemaDeclAttr.cpp

@@ -4652,7 +4652,8 @@ bool Sema::CheckCallingConvAttr(const ParsedAttr &Attrs, CallingConv &CC,
   }
   if (A != TargetInfo::CCCR_OK) {
     if (A == TargetInfo::CCCR_Warning)
-      Diag(Attrs.getLoc(), diag::warn_cconv_ignored) << Attrs;
+      Diag(Attrs.getLoc(), diag::warn_cconv_ignored)
+          << Attrs << (int)CallingConventionIgnoredReason::ForThisTarget;
 
     // This convention is not valid for the target. Use the default function or
     // method calling convention.

clang/lib/Sema/SemaType.cpp

@@ -6930,19 +6930,16 @@ static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
   if (!supportsVariadicCall(CC)) {
     const FunctionProtoType *FnP = dyn_cast<FunctionProtoType>(fn);
     if (FnP && FnP->isVariadic()) {
-      unsigned DiagID = diag::err_cconv_varargs;
-
       // stdcall and fastcall are ignored with a warning for GCC and MS
       // compatibility.
-      bool IsInvalid = true;
-      if (CC == CC_X86StdCall || CC == CC_X86FastCall) {
-        DiagID = diag::warn_cconv_varargs;
-        IsInvalid = false;
-      }
+      if (CC == CC_X86StdCall || CC == CC_X86FastCall)
+        return S.Diag(attr.getLoc(), diag::warn_cconv_ignored)
+               << FunctionType::getNameForCallConv(CC)
+               << (int)Sema::CallingConventionIgnoredReason::VariadicFunction;
 
-      S.Diag(attr.getLoc(), DiagID) << FunctionType::getNameForCallConv(CC);
-      if (IsInvalid) attr.setInvalid();
-      return true;
+      attr.setInvalid();
+      return S.Diag(attr.getLoc(), diag::err_cconv_varargs)
+             << FunctionType::getNameForCallConv(CC);
     }
   }
 
@@ -6997,8 +6994,9 @@ void Sema::adjustMemberFunctionCC(QualType &T, bool IsStatic, bool IsCtorOrDtor,
     // Issue a warning on ignored calling convention -- except of __stdcall.
     // Again, this is what MS compiler does.
     if (CurCC != CC_X86StdCall)
-      Diag(Loc, diag::warn_cconv_structors)
-          << FunctionType::getNameForCallConv(CurCC);
+      Diag(Loc, diag::warn_cconv_ignored)
+          << FunctionType::getNameForCallConv(CurCC)
+          << (int)Sema::CallingConventionIgnoredReason::ConstructorDestructor;
   // Default adjustment.
   } else {
     // Only adjust types with the default convention.  For example, on Windows

clang/test/CodeGen/aarch64-vpcs.c

@@ -2,7 +2,7 @@
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -emit-llvm -x c++ -o - %s | FileCheck %s -check-prefix=CHECKCXX
 // RUN: %clang_cc1 -triple i686-pc-linux-gnu -verify %s
 
-void __attribute__((aarch64_vector_pcs)) f(int *); // expected-warning {{calling convention 'aarch64_vector_pcs' ignored for this target}}
+void __attribute__((aarch64_vector_pcs)) f(int *); // expected-warning {{'aarch64_vector_pcs' calling convention ignored for this target}}
 
 // CHECKC: define void @g(
 // CHECKCXX: define void @_Z1gPi(
@@ -16,7 +16,7 @@ void g(int *a) {
 // CHECKC: declare aarch64_vector_pcs void @f(
 // CHECKCXX: declare aarch64_vector_pcs void @_Z1fPi
 
-void __attribute__((aarch64_vector_pcs)) h(int *a){ // expected-warning {{calling convention 'aarch64_vector_pcs' ignored for this target}}
+void __attribute__((aarch64_vector_pcs)) h(int *a){ // expected-warning {{'aarch64_vector_pcs' calling convention ignored for this target}}
 // CHECKC: define aarch64_vector_pcs void @h(
 // CHECKCXX: define aarch64_vector_pcs void @_Z1hPi(
   f(a);

clang/test/Sema/callingconv-iamcu.c

@@ -1,35 +1,35 @@
 // RUN: %clang_cc1 %s -fsyntax-only -triple i686-intel-elfiamcu -verify
 
-void __attribute__((fastcall)) foo(float *a) { // expected-warning {{calling convention 'fastcall' ignored for this target}}
+void __attribute__((fastcall)) foo(float *a) { // expected-warning {{'fastcall' calling convention ignored for this target}}
 }
 
-void __attribute__((stdcall)) bar(float *a) { // expected-warning {{calling convention 'stdcall' ignored for this target}}
+void __attribute__((stdcall)) bar(float *a) { // expected-warning {{'stdcall' calling convention ignored for this target}}
 }
 
 void __attribute__((fastcall(1))) baz(float *a) { // expected-error {{'fastcall' attribute takes no arguments}}
 }
 
-void __attribute__((fastcall)) test2(int a, ...) { // expected-warning {{calling convention 'fastcall' ignored for this target}}
+void __attribute__((fastcall)) test2(int a, ...) { // expected-warning {{'fastcall' calling convention ignored for this target}}
 }
-void __attribute__((stdcall)) test3(int a, ...) { // expected-warning {{calling convention 'stdcall' ignored for this target}}
+void __attribute__((stdcall)) test3(int a, ...) { // expected-warning {{'stdcall' calling convention ignored for this target}}
 }
-void __attribute__((thiscall)) test4(int a, ...) { // expected-warning {{calling convention 'thiscall' ignored for this target}}
+void __attribute__((thiscall)) test4(int a, ...) { // expected-warning {{'thiscall' calling convention ignored for this target}}
 }
 
 void __attribute__((cdecl)) ctest0() {}
 
 void __attribute__((cdecl(1))) ctest1(float x) {} // expected-error {{'cdecl' attribute takes no arguments}}
 
-void (__attribute__((fastcall)) *pfoo)(float*) = foo; // expected-warning {{calling convention 'fastcall' ignored for this target}}
+void (__attribute__((fastcall)) *pfoo)(float*) = foo; // expected-warning {{'fastcall' calling convention ignored for this target}}
 
-void (__attribute__((stdcall)) *pbar)(float*) = bar; // expected-warning {{calling convention 'stdcall' ignored for this target}}
+void (__attribute__((stdcall)) *pbar)(float*) = bar; // expected-warning {{'stdcall' calling convention ignored for this target}}
 
 void (*pctest0)() = ctest0;
 
 void ctest2() {}
 void (__attribute__((cdecl)) *pctest2)() = ctest2;
 
-typedef void (__attribute__((fastcall)) *Handler) (float *); // expected-warning {{calling convention 'fastcall' ignored for this target}}
+typedef void (__attribute__((fastcall)) *Handler) (float *); // expected-warning {{'fastcall' calling convention ignored for this target}}
 Handler H = foo;
 
 int __attribute__((pcs("aapcs", "aapcs"))) pcs1(void); // expected-error {{'pcs' attribute takes one argument}}
@@ -38,16 +38,16 @@ int __attribute__((pcs(pcs1))) pcs3(void); // expected-error {{'pcs' attribute r
                                            // expected-error {{invalid PCS type}}
 int __attribute__((pcs(0))) pcs4(void); // expected-error {{'pcs' attribute requires a string}}
 /* These are ignored because the target is i386 and not ARM */
-int __attribute__((pcs("aapcs"))) pcs5(void); // expected-warning {{calling convention 'pcs' ignored for this target}}
-int __attribute__((pcs("aapcs-vfp"))) pcs6(void); // expected-warning {{calling convention 'pcs' ignored for this target}}
+int __attribute__((pcs("aapcs"))) pcs5(void); // expected-warning {{'pcs' calling convention ignored for this target}}
+int __attribute__((pcs("aapcs-vfp"))) pcs6(void); // expected-warning {{'pcs' calling convention ignored for this target}}
 int __attribute__((pcs("foo"))) pcs7(void); // expected-error {{invalid PCS type}}
 
 void ctest3();
 void __attribute__((cdecl)) ctest3() {}
 
-typedef __attribute__((stdcall)) void (*PROC)(); // expected-warning {{calling convention 'stdcall' ignored for this target}}
+typedef __attribute__((stdcall)) void (*PROC)(); // expected-warning {{'stdcall' calling convention ignored for this target}}
 PROC __attribute__((cdecl)) ctest4(const char *x) {}
 
-void __attribute__((intel_ocl_bicc)) inteloclbifunc(float *a) {} // expected-warning {{calling convention 'intel_ocl_bicc' ignored for this target}}
+void __attribute__((intel_ocl_bicc)) inteloclbifunc(float *a) {} // expected-warning {{'intel_ocl_bicc' calling convention ignored for this target}}
 
-struct type_test {} __attribute__((stdcall)); // expected-warning {{calling convention 'stdcall' ignored for this target}} expected-warning {{'stdcall' attribute only applies to functions and methods}}
+struct type_test {} __attribute__((stdcall)); // expected-warning {{'stdcall' calling convention ignored for this target}} expected-warning {{'stdcall' attribute only applies to functions and methods}}

clang/test/Sema/callingconv.c

@@ -47,11 +47,11 @@ int __attribute__((pcs(pcs1))) pcs3(void); // expected-error {{'pcs' attribute r
                                            // expected-error {{invalid PCS type}}
 int __attribute__((pcs(0))) pcs4(void); // expected-error {{'pcs' attribute requires a string}}
 /* These are ignored because the target is i386 and not ARM */
-int __attribute__((pcs("aapcs"))) pcs5(void); // expected-warning {{calling convention 'pcs' ignored for this target}}
-int __attribute__((pcs("aapcs-vfp"))) pcs6(void); // expected-warning {{calling convention 'pcs' ignored for this target}}
+int __attribute__((pcs("aapcs"))) pcs5(void); // expected-warning {{'pcs' calling convention ignored for this target}}
+int __attribute__((pcs("aapcs-vfp"))) pcs6(void); // expected-warning {{'pcs' calling convention ignored for this target}}
 int __attribute__((pcs("foo"))) pcs7(void); // expected-error {{invalid PCS type}}
 
-int __attribute__((aarch64_vector_pcs)) aavpcs(void); // expected-warning {{calling convention 'aarch64_vector_pcs' ignored for this target}}
+int __attribute__((aarch64_vector_pcs)) aavpcs(void); // expected-warning {{'aarch64_vector_pcs' calling convention ignored for this target}}
 
 // PR6361
 void ctest3();
@@ -68,3 +68,5 @@ typedef_fun_t typedef_fun; // expected-note {{previous declaration is here}}
 void __attribute__((stdcall)) typedef_fun(int x) { } // expected-error {{function declared 'stdcall' here was previously declared without calling convention}}
 
 struct type_test {} __attribute__((stdcall));  // expected-warning {{'stdcall' attribute only applies to functions and methods}}
+
+void __vectorcall __builtin_unreachable(); // expected-warning {{vectorcall calling convention ignored on builtin function}}

clang/test/Sema/pr25786.c

@@ -2,8 +2,8 @@
 // RUN: %clang_cc1 -triple i686-unknown-linux-gnu -fsyntax-only -verify %s
 
 #if TEST
-void (__attribute__((regparm(3), stdcall)) *pf) (); //expected-warning {{calling convention 'stdcall' ignored for this target}}
-void (__attribute__((regparm(2), stdcall)) foo)(int a) { //expected-warning {{calling convention 'stdcall' ignored for this target}}
+void (__attribute__((regparm(3), stdcall)) *pf) (); //expected-warning {{'stdcall' calling convention ignored for this target}}
+void (__attribute__((regparm(2), stdcall)) foo)(int a) { //expected-warning {{'stdcall' calling convention ignored for this target}}
 }
 #else
 //expected-no-diagnostics

clang/test/Sema/stdcall-fastcall-x64.c

@@ -5,16 +5,16 @@ int __attribute__((stdcall)) var1; // expected-warning{{'stdcall' only applies t
 int __attribute__((fastcall)) var2; // expected-warning{{'fastcall' only applies to function types; type here is 'int'}}
 
 // Different CC qualifiers are not compatible
-void __attribute__((stdcall, fastcall)) foo3(void); // expected-warning{{calling convention 'stdcall' ignored for this target}} expected-warning {{calling convention 'fastcall' ignored for this target}}
-void __attribute__((stdcall)) foo4(); // expected-warning{{calling convention 'stdcall' ignored for this target}}
-void __attribute__((fastcall)) foo4(void); // expected-warning {{calling convention 'fastcall' ignored for this target}}
+void __attribute__((stdcall, fastcall)) foo3(void); // expected-warning{{'stdcall' calling convention ignored for this target}} expected-warning {{'fastcall' calling convention ignored for this target}}
+void __attribute__((stdcall)) foo4(); // expected-warning{{'stdcall' calling convention ignored for this target}}
+void __attribute__((fastcall)) foo4(void); // expected-warning {{'fastcall' calling convention ignored for this target}}
 
 // rdar://8876096
-void rdar8876096foo1(int i, int j) __attribute__((fastcall, cdecl)); // expected-warning{{calling convention 'fastcall' ignored for this target}}
-void rdar8876096foo2(int i, int j) __attribute__((fastcall, stdcall)); // expected-warning{{calling convention 'stdcall' ignored for this target}} expected-warning {{calling convention 'fastcall' ignored for this target}}
-void rdar8876096foo3(int i, int j) __attribute__((fastcall, regparm(2))); // expected-warning {{calling convention 'fastcall' ignored for this target}}
-void rdar8876096foo4(int i, int j) __attribute__((stdcall, cdecl)); // expected-warning{{calling convention 'stdcall' ignored for this target}}
-void rdar8876096foo5(int i, int j) __attribute__((stdcall, fastcall)); // expected-warning{{calling convention 'stdcall' ignored for this target}} expected-warning {{calling convention 'fastcall' ignored for this target}}
-void rdar8876096foo6(int i, int j) __attribute__((cdecl, fastcall)); // expected-warning {{calling convention 'fastcall' ignored for this target}}
-void rdar8876096foo7(int i, int j) __attribute__((cdecl, stdcall)); // expected-warning{{calling convention 'stdcall' ignored for this target}}
-void rdar8876096foo8(int i, int j) __attribute__((regparm(2), fastcall)); // expected-warning {{calling convention 'fastcall' ignored for this target}}
+void rdar8876096foo1(int i, int j) __attribute__((fastcall, cdecl)); // expected-warning{{'fastcall' calling convention ignored for this target}}
+void rdar8876096foo2(int i, int j) __attribute__((fastcall, stdcall)); // expected-warning{{'stdcall' calling convention ignored for this target}} expected-warning {{'fastcall' calling convention ignored for this target}}
+void rdar8876096foo3(int i, int j) __attribute__((fastcall, regparm(2))); // expected-warning {{'fastcall' calling convention ignored for this target}}
+void rdar8876096foo4(int i, int j) __attribute__((stdcall, cdecl)); // expected-warning{{'stdcall' calling convention ignored for this target}}
+void rdar8876096foo5(int i, int j) __attribute__((stdcall, fastcall)); // expected-warning{{'stdcall' calling convention ignored for this target}} expected-warning {{'fastcall' calling convention ignored for this target}}
+void rdar8876096foo6(int i, int j) __attribute__((cdecl, fastcall)); // expected-warning {{'fastcall' calling convention ignored for this target}}
+void rdar8876096foo7(int i, int j) __attribute__((cdecl, stdcall)); // expected-warning{{'stdcall' calling convention ignored for this target}}
+void rdar8876096foo8(int i, int j) __attribute__((regparm(2), fastcall)); // expected-warning {{'fastcall' calling convention ignored for this target}}

clang/test/SemaCUDA/cuda-inherits-calling-conv.cu

@@ -24,7 +24,7 @@ struct Foo<T()> {};
 // expected-no-diagnostics
 #else
 // expected-error@+4 {{redefinition of 'Foo}}
-// expected-warning@+3 {{calling convention '__fastcall' ignored}}
+// expected-warning@+3 {{'__fastcall' calling convention ignored}}
 #endif
 template <class T>
 struct Foo<T __fastcall()> {};

clang/test/SemaCXX/borland-extensions.cpp

@@ -7,21 +7,21 @@
 int dummy_function() { return 0; }
 
 // 2. test __pascal
-// expected-warning@+1 {{calling convention '_pascal' ignored for this target}}
+// expected-warning@+1 {{'_pascal' calling convention ignored for this target}}
 int _pascal f2();
 
-// expected-warning@+1 {{calling convention '__pascal' ignored for this target}}
+// expected-warning@+1 {{'__pascal' calling convention ignored for this target}}
 float __pascal gi2(int, int); 
-// expected-warning@+1 {{calling convention '__pascal' ignored for this target}}
+// expected-warning@+1 {{'__pascal' calling convention ignored for this target}}
 template<typename T> T g2(T (__pascal * const )(int, int)) { return 0; }
 
 struct M {
-    // expected-warning@+1 {{calling convention '__pascal' ignored for this target}}
+    // expected-warning@+1 {{'__pascal' calling convention ignored for this target}}
     int __pascal addP();
-    // expected-warning@+1 {{calling convention '__pascal' ignored for this target}}
+    // expected-warning@+1 {{'__pascal' calling convention ignored for this target}}
     float __pascal subtractP(); 
 };
-// expected-warning@+1 {{calling convention '__pascal' ignored for this target}}
+// expected-warning@+1 {{'__pascal' calling convention ignored for this target}}
 template<typename T> int h2(T (__pascal M::* const )()) { return 0; }
 void m2() {
     int i; float f;
@@ -34,9 +34,9 @@ void m2() {
 
 // 3. test other calling conventions
 int _cdecl fa3();
-// expected-warning@+1 {{calling convention '_fastcall' ignored for this target}}
+// expected-warning@+1 {{'_fastcall' calling convention ignored for this target}}
 int _fastcall fc3();
-// expected-warning@+1 {{calling convention '_stdcall' ignored for this target}}
+// expected-warning@+1 {{'_stdcall' calling convention ignored for this target}}
 int _stdcall fd3();
 
 // 4. test __uuidof()

clang/test/SemaCXX/cxx11-gnu-attrs.cpp

@@ -9,18 +9,18 @@ int [[gnu::unused]] attr_on_type;
 int *[[gnu::unused]] attr_on_ptr;
 // expected-warning@-1 {{attribute 'unused' ignored, because it cannot be applied to a type}}
 [[gnu::fastcall]] void pr17424_1();
-// expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
+// expected-warning@-1 {{'fastcall' calling convention ignored for this target}}
 [[gnu::fastcall]] [[gnu::stdcall]] void pr17424_2();
-// expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
-// expected-warning@-2 {{calling convention 'stdcall' ignored for this target}}
+// expected-warning@-1 {{'fastcall' calling convention ignored for this target}}
+// expected-warning@-2 {{'stdcall' calling convention ignored for this target}}
 [[gnu::fastcall]] __stdcall void pr17424_3();
-// expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
-// expected-warning@-2 {{calling convention '__stdcall' ignored for this target}}
+// expected-warning@-1 {{'fastcall' calling convention ignored for this target}}
+// expected-warning@-2 {{'__stdcall' calling convention ignored for this target}}
 [[gnu::fastcall]] void pr17424_4() [[gnu::stdcall]];
-// expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
-// expected-warning@-2 {{calling convention 'stdcall' ignored for this target}}
+// expected-warning@-1 {{'fastcall' calling convention ignored for this target}}
+// expected-warning@-2 {{'stdcall' calling convention ignored for this target}}
 void pr17424_5 [[gnu::fastcall]]();
-// expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
+// expected-warning@-1 {{'fastcall' calling convention ignored for this target}}
 
 // Valid cases.
 

clang/test/SemaCXX/virtual-override-x64.cpp

@@ -6,7 +6,7 @@
 namespace PR14339 {
   class A {
   public:
-    virtual void __attribute__((thiscall)) f();	// expected-warning {{calling convention 'thiscall' ignored for this target}}
+    virtual void __attribute__((thiscall)) f();	// expected-warning {{'thiscall' calling convention ignored for this target}}
   };
 
   class B : public A {
@@ -16,7 +16,7 @@ namespace PR14339 {
 
   class C : public A {
   public:
-    void __attribute__((thiscall)) f();  // expected-warning {{calling convention 'thiscall' ignored for this target}}
+    void __attribute__((thiscall)) f();  // expected-warning {{'thiscall' calling convention ignored for this target}}
   };
 
   class D : public A {
@@ -26,7 +26,7 @@ namespace PR14339 {
 
   class E {
   public:
-    virtual void __attribute__((stdcall)) g();  // expected-warning {{calling convention 'stdcall' ignored for this target}}
+    virtual void __attribute__((stdcall)) g();  // expected-warning {{'stdcall' calling convention ignored for this target}}
   };
 
   class F : public E {

clang/test/SemaTemplate/instantiate-function-params.cpp

@@ -88,7 +88,7 @@ namespace InstantiateFunctionTypedef {
     __attribute__((stdcall)) functype stdfunc1;
     stdfunctype stdfunc2;
 
-    __attribute__((pcs("aapcs"))) functype pcsfunc; // expected-warning {{calling convention 'pcs' ignored for this target}}
+    __attribute__((pcs("aapcs"))) functype pcsfunc; // expected-warning {{'pcs' calling convention ignored for this target}}
   };
 
   void f(X<int> x) {