Add support for MSVC's __FUNCSIG__

[rnk]

Summary

It is very similar to GCC's PRETTY_FUNCTION, except it prints the
calling convention.

[majnemer]

LGTM

Note that there is a bit of divergence here with MSVC, we choose different names for the GlobalVariable holding the string constant.

I suppose it would be nicer for the names to match and fold but that is a relatively minor thing, nothing to hold up this patch.

[rnk]

Thanks! I added a FIXME for the mangling thing. We want to make sure that FUNC* in inline functions gets merged.

[rnk]

Closed by commit rL205780 (authored by @rnk).

cfe/trunk/include/clang/AST/Expr.h

 /// PredefinedExpr - [C99 6.4.2.2] - A predefined identifier such as __func__.
 class PredefinedExpr : public Expr {
 public:
   enum IdentType {
     Func,
     Function,
     LFunction,  // Same as Function, but as wide string.
     FuncDName,
+    FuncSig,
     PrettyFunction,
     /// PrettyFunctionNoVirtual - The same as PrettyFunction, except that the
     /// 'virtual' keyword is omitted for virtual member functions.
     PrettyFunctionNoVirtual
   };
 
 private:
   SourceLocation Loc;

cfe/trunk/include/clang/Basic/TokenKinds.def

 KEYWORD(__FUNCTION__                , KEYALL)
 KEYWORD(__PRETTY_FUNCTION__         , KEYALL)
 
 // GNU Extensions (outside impl-reserved namespace)
 KEYWORD(typeof                      , KEYGNU)
 
 // MS Extensions
 KEYWORD(__FUNCDNAME__               , KEYMS)
+KEYWORD(__FUNCSIG__                 , KEYMS)
 KEYWORD(L__FUNCTION__               , KEYMS)
 TYPE_TRAIT_1(__is_interface_class, IsInterfaceClass, KEYMS)
 TYPE_TRAIT_1(__is_sealed, IsSealed, KEYMS)
 
 // MSVC12.0 / VS2013 Type Traits
 TYPE_TRAIT_1(__is_destructible, IsDestructible, KEYMS)
 TYPE_TRAIT_1(__is_nothrow_destructible, IsNothrowDestructible, KEYMS)
 TYPE_TRAIT_2(__is_nothrow_assignable, IsNothrowAssignable, KEYCXX)

cfe/trunk/lib/AST/ASTDumper.cpp

void ASTDumper::VisitPredefinedExpr(const PredefinedExpr *Node) {
   VisitExpr(Node);
   switch (Node->getIdentType()) {
   default: llvm_unreachable("unknown case");
   case PredefinedExpr::Func:           OS <<  " __func__"; break;
   case PredefinedExpr::Function:       OS <<  " __FUNCTION__"; break;
   case PredefinedExpr::FuncDName:      OS <<  " __FUNCDNAME__"; break;
   case PredefinedExpr::LFunction:      OS <<  " L__FUNCTION__"; break;
   case PredefinedExpr::PrettyFunction: OS <<  " __PRETTY_FUNCTION__";break;
+  case PredefinedExpr::FuncSig:        OS <<  " __FUNCSIG__"; break;
   }
 }
 
 void ASTDumper::VisitCharacterLiteral(const CharacterLiteral *Node) {
   VisitExpr(Node);
   ColorScope Color(*this, ValueColor);
   OS << " " << Node->getValue();
 }

cfe/trunk/lib/AST/Expr.cpp

if (const NamedDecl *ND = dyn_cast<NamedDecl>(CurrentDecl)) {
           return Buffer.substr(1);
         return Buffer.str();
       } else
         return ND->getIdentifier()->getName();
     }
     return "";
   }
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {
-    if (IT != PrettyFunction && IT != PrettyFunctionNoVirtual)
+    if (IT != PrettyFunction && IT != PrettyFunctionNoVirtual && IT != FuncSig)
       return FD->getNameAsString();
 
     SmallString<256> Name;
     llvm::raw_svector_ostream Out(Name);
 
     if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
       if (MD->isVirtual() && IT != PrettyFunctionNoVirtual)
         Out << "virtual ";
       if (MD->isStatic())
         Out << "static ";
     }
 
     PrintingPolicy Policy(Context.getLangOpts());
     std::string Proto;
     llvm::raw_string_ostream POut(Proto);
-    FD->printQualifiedName(POut, Policy);
 
     const FunctionDecl *Decl = FD;
     if (const FunctionDecl* Pattern = FD->getTemplateInstantiationPattern())
       Decl = Pattern;
     const FunctionType *AFT = Decl->getType()->getAs<FunctionType>();
     const FunctionProtoType *FT = 0;
     if (FD->hasWrittenPrototype())
       FT = dyn_cast<FunctionProtoType>(AFT);
 
+    if (IT == FuncSig) {
+      switch (FT->getCallConv()) {
+      case CC_C: POut << "__cdecl "; break;
+      case CC_X86StdCall: POut << "__stdcall "; break;
+      case CC_X86FastCall: POut << "__fastcall "; break;
+      case CC_X86ThisCall: POut << "__thiscall "; break;
+      // Only bother printing the conventions that MSVC knows about.
+      default: break;
+      }
+    }
+
+    FD->printQualifiedName(POut, Policy);
+
     POut << "(";
     if (FT) {
       for (unsigned i = 0, e = Decl->getNumParams(); i != e; ++i) {
         if (i) POut << ", ";
         POut << Decl->getParamDecl(i)->getType().stream(Policy);
       }
 
       if (FT->isVariadic()) {

cfe/trunk/lib/AST/StmtPrinter.cpp

case PredefinedExpr::Func:
       OS << "__func__";
       break;
     case PredefinedExpr::Function:
       OS << "__FUNCTION__";
       break;
     case PredefinedExpr::FuncDName:
       OS << "__FUNCDNAME__";
       break;
+    case PredefinedExpr::FuncSig:
+      OS << "__FUNCSIG__";
+      break;
     case PredefinedExpr::LFunction:
       OS << "L__FUNCTION__";
       break;
     case PredefinedExpr::PrettyFunction:
       OS << "__PRETTY_FUNCTION__";
       break;
   }
 }

cfe/trunk/lib/CodeGen/CGExpr.cpp

LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
   switch (E->getIdentType()) {
   default:
     return EmitUnsupportedLValue(E, "predefined expression");
 
   case PredefinedExpr::Func:
   case PredefinedExpr::Function:
   case PredefinedExpr::LFunction:
   case PredefinedExpr::FuncDName:
+  case PredefinedExpr::FuncSig:
   case PredefinedExpr::PrettyFunction: {
     PredefinedExpr::IdentType IdentType = E->getIdentType();
-    std::string GlobalVarName;
+    std::string GVName;
 
+    // FIXME: We should use the string literal mangling for the Microsoft C++
+    // ABI so that strings get merged.
     switch (IdentType) {
     default: llvm_unreachable("Invalid type");
-    case PredefinedExpr::Func:
-      GlobalVarName = "__func__.";
-      break;
-    case PredefinedExpr::Function:
-      GlobalVarName = "__FUNCTION__.";
-      break;
-    case PredefinedExpr::FuncDName:
-      GlobalVarName = "__FUNCDNAME__.";
-      break;
-    case PredefinedExpr::LFunction:
-      GlobalVarName = "L__FUNCTION__.";
-      break;
-    case PredefinedExpr::PrettyFunction:
-      GlobalVarName = "__PRETTY_FUNCTION__.";
-      break;
+    case PredefinedExpr::Func:           GVName = "__func__."; break;
+    case PredefinedExpr::Function:       GVName = "__FUNCTION__."; break;
+    case PredefinedExpr::FuncDName:      GVName = "__FUNCDNAME__."; break;
+    case PredefinedExpr::FuncSig:        GVName = "__FUNCSIG__."; break;
+    case PredefinedExpr::LFunction:      GVName = "L__FUNCTION__."; break;
+    case PredefinedExpr::PrettyFunction: GVName = "__PRETTY_FUNCTION__."; break;
     }
 
     StringRef FnName = CurFn->getName();
     if (FnName.startswith("\01"))
       FnName = FnName.substr(1);
-    GlobalVarName += FnName;
+    GVName += FnName;
 
     // If this is outside of a function use the top level decl.
     const Decl *CurDecl = CurCodeDecl;
     if (CurDecl == 0 || isa<VarDecl>(CurDecl))
       CurDecl = getContext().getTranslationUnitDecl();
 
     const Type *ElemType = E->getType()->getArrayElementTypeNoTypeQual();
     std::string FunctionName;
case PredefinedExpr::PrettyFunction: {
 
     llvm::Constant *C;
     if (ElemType->isWideCharType()) {
       SmallString<32> RawChars;
       ConvertUTF8ToWideString(
           getContext().getTypeSizeInChars(ElemType).getQuantity(),
           FunctionName, RawChars);
       C = GetAddrOfConstantWideString(RawChars,
-                                      GlobalVarName.c_str(),
+                                      GVName.c_str(),
                                       getContext(),
                                       E->getType(),
                                       E->getLocation(),
                                       CGM);
     } else {
-      C = CGM.GetAddrOfConstantCString(FunctionName,
-                                       GlobalVarName.c_str(),
-                                       1);
+      C = CGM.GetAddrOfConstantCString(FunctionName, GVName.c_str(), 1);
     }
     return MakeAddrLValue(C, E->getType());
   }
   }
 }
 
 /// Emit a type description suitable for use by a runtime sanitizer library. The
 /// format of a type descriptor is

cfe/trunk/lib/Parse/ParseExpr.cpp

ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
   case tok::utf16_char_constant:
   case tok::utf32_char_constant:
     Res = Actions.ActOnCharacterConstant(Tok, /*UDLScope*/getCurScope());
     ConsumeToken();
     break;
   case tok::kw___func__:       // primary-expression: __func__ [C99 6.4.2.2]
   case tok::kw___FUNCTION__:   // primary-expression: __FUNCTION__ [GNU]
   case tok::kw___FUNCDNAME__:   // primary-expression: __FUNCDNAME__ [MS]
+  case tok::kw___FUNCSIG__:     // primary-expression: __FUNCSIG__ [MS]
   case tok::kw_L__FUNCTION__:   // primary-expression: L__FUNCTION__ [MS]
   case tok::kw___PRETTY_FUNCTION__:  // primary-expression: __P..Y_F..N__ [GNU]
     Res = Actions.ActOnPredefinedExpr(Tok.getLocation(), SavedKind);
     ConsumeToken();
     break;
   case tok::string_literal:    // primary-expression: string-literal
   case tok::wide_string_literal:
   case tok::utf8_string_literal:

cfe/trunk/lib/Parse/ParseTentative.cpp

Parser::isExpressionOrTypeSpecifierSimple(tok::TokenKind Kind) {
   case tok::kw___alignof:
   case tok::kw___builtin_choose_expr:
   case tok::kw___builtin_offsetof:
   case tok::kw___builtin_va_arg:
   case tok::kw___imag:
   case tok::kw___real:
   case tok::kw___FUNCTION__:
   case tok::kw___FUNCDNAME__:
+  case tok::kw___FUNCSIG__:
   case tok::kw_L__FUNCTION__:
   case tok::kw___PRETTY_FUNCTION__:
   case tok::kw___uuidof:
 #define TYPE_TRAIT(N,Spelling,K) \
   case tok::kw_##Spelling:
 #include "clang/Basic/TokenKinds.def"
     return TPResult::True();
       

cfe/trunk/lib/Sema/SemaExpr.cpp

 ExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, tok::TokenKind Kind) {
   PredefinedExpr::IdentType IT;
 
   switch (Kind) {
   default: llvm_unreachable("Unknown simple primary expr!");
   case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2]
   case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break;
   case tok::kw___FUNCDNAME__: IT = PredefinedExpr::FuncDName; break; // [MS]
+  case tok::kw___FUNCSIG__: IT = PredefinedExpr::FuncSig; break; // [MS]
   case tok::kw_L__FUNCTION__: IT = PredefinedExpr::LFunction; break;
   case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break;
   }
 
   return BuildPredefinedExpr(Loc, IT);
 }
 
 ExprResult Sema::ActOnCharacterConstant(const Token &Tok, Scope *UDLScope) {

cfe/trunk/test/CodeGenCXX/funcsig.cpp

+// RUN: %clang_cc1 -std=c++11 %s -fms-extensions -fno-rtti -emit-llvm -o - | FileCheck %s
+
+// Similar to predefined-expr.cpp, but not as exhaustive, since it's basically
+// equivalent to __PRETTY_FUNCTION__.
+
+extern "C" int printf(const char *, ...);
+
+void freeFunc(int *, char) {
+  printf("__FUNCSIG__ %s\n\n", __FUNCSIG__);
+}
+// CHECK: private unnamed_addr constant [{{.*}} x i8] c"void __cdecl freeFunc(int *, char)\00"
+
+struct TopLevelClass {
+  void topLevelMethod(int *, char);
+};
+void TopLevelClass::topLevelMethod(int *, char) {
+  printf("__FUNCSIG__ %s\n\n", __FUNCSIG__);
+}
+// CHECK: private unnamed_addr constant [{{.*}} x i8] c"void __thiscall TopLevelClass::topLevelMethod(int *, char)\00"
+
+namespace NS {
+struct NamespacedClass {
+  void namespacedMethod(int *, char);
+};
+void NamespacedClass::namespacedMethod(int *, char) {
+  printf("__FUNCSIG__ %s\n\n", __FUNCSIG__);
+}
+// CHECK: private unnamed_addr constant [{{.*}} x i8] c"void __thiscall NS::NamespacedClass::namespacedMethod(int *, char)\00"
+}