[-fms-extensions] Add support for __FUNCDNAME__

Summary:
Similar to __FUNCTION__, MSVC exposes the name of the enclosing mangled
function name via __FUNCDNAME__.  This implementation is very naive and
unoptimized, it is expected that __FUNCDNAME__ would be used rarely in
practice.

Reviewers: rnk, rsmith, thakis

CC: cfe-commits, silvas

Differential Revision: http://llvm-reviews.chandlerc.com/D2109

llvm-svn: 194181

1 files changed, 25 insertions, 0 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 38f5e2f4887..e467883288b 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -20,6 +20,7 @@
 #include "clang/AST/EvaluatedExprVisitor.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
+#include "clang/AST/Mangle.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/AST/StmtVisitor.h"
 #include "clang/Basic/Builtins.h"
@@ -478,6 +479,30 @@ SourceLocation DeclRefExpr::getLocEnd() const {
 std::string PredefinedExpr::ComputeName(IdentType IT, const Decl *CurrentDecl) {
   ASTContext &Context = CurrentDecl->getASTContext();
 
+  if (IT == PredefinedExpr::FuncDName) {
+    if (const NamedDecl *ND = dyn_cast<NamedDecl>(CurrentDecl)) {
+      OwningPtr<MangleContext> MC;
+      MC.reset(Context.createMangleContext());
+
+      if (MC->shouldMangleDeclName(ND)) {
+        SmallString<256> Buffer;
+        llvm::raw_svector_ostream Out(Buffer);
+        if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(ND))
+          MC->mangleCXXCtor(CD, Ctor_Base, Out);
+        else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(ND))
+          MC->mangleCXXDtor(DD, Dtor_Base, Out);
+        else
+          MC->mangleName(ND, Out);
+
+        Out.flush();
+        if (!Buffer.empty() && Buffer.front() == '\01')
+          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)
       return FD->getNameAsString();