如何设置Clang使用MinGW libstdc++

我一直在尝试在Windows上设置Clang。到目前为止，我在Visual Studio和CMake的帮助下幸存了下来，还有一些其他的惊喜。但是Clang没有自己的c++标准库实现，所以我决定使用GCC 4.7.0为MinGW构建的libstdc++。

首先，我将搜索路径添加到我的HeaderSearchOptions中。

headeropts->AddPath(path, clang::frontend::IncludeDirGroup::CXXSystem, true, false, false);

路径正是头文件所在的位置——我从Windows资源管理器复制并粘贴了它(然后将反斜杠加倍用于转义)。但是Clang仍然坚持找不到<iostream>，即使一个名为iostream的文件正好存在于path。

为什么Clang不能找到我的头文件，我还需要做什么才能使用libstdc++?

这是我的代码

llvm::LLVMContext c;
llvm::Module m("", c);
clang::CompilerInstance ci;
clang::FileSystemOptions fso;
clang::FileManager fm(fso);
std::string errors;
llvm::raw_string_ostream error_stream(errors);
clang::DiagnosticOptions diagopts;
clang::TextDiagnosticPrinter printer(error_stream, &diagopts);
llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs> diagids(new clang::DiagnosticIDs);
clang::DiagnosticsEngine engine(diagids, &diagopts, &printer, false);
clang::SourceManager sm(engine, fm);
clang::LangOptions langopts;
langopts.CPlusPlus = true;
langopts.CPlusPlus0x = true;
clang::TargetOptions target;
target.Triple = llvm::sys::getDefaultTargetTriple();
auto targetinfo = clang::TargetInfo::CreateTargetInfo(engine, &target);
auto headeropts = llvm::IntrusiveRefCntPtr<clang::HeaderSearchOptions>(new clang::HeaderSearchOptions());
headeropts->AddPath("D:\Backups\unsorted\x86_64-w64-mingw32-gcc-4.7.0-release-win64_rubenvb\mingw64\include\c++\4.7.0",clang::frontend::IncludeDirGroup::CXXSystem, true, false, false);
headeropts->UseStandardCXXIncludes = true;
headeropts->UseStandardSystemIncludes = true;
clang::HeaderSearch hs(headeropts, fm, engine, langopts, targetinfo);
auto x = llvm::IntrusiveRefCntPtr<clang::PreprocessorOptions>(new clang::PreprocessorOptions());
clang::Preprocessor p(x, engine, langopts, targetinfo, sm, hs, ci);
clang::ASTContext astcon(langopts, sm, targetinfo, p.getIdentifierTable(), p.getSelectorTable(), p.getBuiltinInfo(), 1000);
CodeGenConsumer consumer;
clang::CodeGen::CodeGenModule codegen(astcon, clang::CodeGenOptions(), m, llvm::DataLayout(&m), engine);
consumer.mod = &codegen;
clang::Sema sema(p, astcon, consumer, clang::TranslationUnitKind::TU_Complete);
sm.createMainFileID(fm.getFile("main.cpp"));
engine.getClient()->BeginSourceFile(langopts, &p);
clang::ParseAST(sema);