[cfe-commits] r64413 - in /cfe/trunk: include/clang/AST/DeclBase.h lib/CodeGen/CGDecl.cpp lib/CodeGen/CGExpr.cpp lib/CodeGen/CMakeLists.txt lib/CodeGen/CodeGenFunction.cpp lib/CodeGen/CodeGenModule.cpp lib/CodeGen/CodeGenModule.h lib/CodeGen/Mangle.cpp lib/CodeGen/Mangle.h test/CodeGen/overloadable.c test/CodeGenCXX/mangle.cpp

[Chris Lattner]

On Feb 12, 2009, at 4:10 PM, Douglas Gregor wrote:
> URL: http://llvm.org/viewvc/llvm-project?rev=64413&view=rev
> Log:
> Add basic support for C++ name mangling according to the Itanium C++
> ABI to the CodeGen library. Since C++ code-generation is so
> incomplete, we can't exercise much of this mangling code. However, a
> few smoke tests show that it's doing the same thing as GCC. When C++
> codegen matures, we'll extend the ABI tester to verify name-mangling
> as well, and complete the implementation here.

Very nice Doug, thank you for working on this!

> +/// \brief Retrieves the mangled name for the given declaration.
> +///
> +/// If the given declaration requires a mangled name, returns an
> +/// IdentifierInfo* containing the mangled name. Otherwise, returns
> +/// the name of the declaration as an identifier.
> +///
> +/// FIXME: Returning an IdentifierInfo* here is a total hack. We

Yes, yes it is.  Please use a llvm/ADT/StringSet.h in CodeGenModule to  
hold these.

> +/// FIXME: Performance here is going to be terribly until we start
> +/// caching mangled names. However, we should fix the problem above
> +/// first.

Right.

> +IdentifierInfo *CodeGenModule::getMangledName(const NamedDecl *ND)  
> const {
> +  std::string Name;

Also, please use a SmallString<256> or something like that to avoid  
heap traffic.

> @@ -0,0 +1,516 @@
> +//===--------------------- Mangle.cpp - Mangle C++ Names  
> ------------------===//

Any reason to center this?

> +bool CXXNameMangler::mangle(const NamedDecl *D) {
> +  // <mangled-name> ::= _Z <encoding>
> +  //            ::= <data name>
> +  //            ::= <special-name>
> +
> +  // FIXME: Actually use a visitor to decode these?
> +  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
> +    bool RequiresMangling = false;
> +    // Clang's "overloadable" attribute extension to C/C++
> +    if (FD->getAttr<OverloadableAttr>())
> +      RequiresMangling = true;
> +    else if (Context.getLangOptions().CPlusPlus) {
> +      RequiresMangling = true;
> +      if (isa<LinkageSpecDecl>(FD->getDeclContext()) &&
> +          cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage()
> +            == LinkageSpecDecl::lang_c) {

IS:

extern "C" {
   namespace foo {
     int bar();
   }
}

legal?  If so, you'd have to check all parent contexts for an extern c  
block.  Also, you should check SourceManager::getFileCharacteristic on  
the decl's location to see if it is in an "implicit extern C system  
header".

> +static bool isStdNamespace(const DeclContext *DC) {
> +  if (!DC->isNamespace() || !DC->getParent()->isTranslationUnit())
> +    return false;
> +
> +  const NamespaceDecl *NS = cast<NamespaceDecl>(DC);
> +  const IdentifierInfo *Name = NS->getIdentifier();
> +  if (Name->getLength() != 3)
> +    return false;
> +
> +  const char *Str = Name->getName();
> +  if (Str[0] != 's' || Str[1] != 't' || Str[2] != 'd')
> +    return false;

return NS->getIdentifier()->isStr("std");

should be enough.

> +  case NUM_OVERLOADED_OPERATORS:
> +    assert(false && "Not an ovelroaded operator");

typo

> @@ -0,0 +1,32 @@
> +//===---------------------- Mangle.h - Mangle C++ Names  
> -------------------===//

Likewise, centering.

-Chris