Driver: Add a -stdlib= argument which can be used to select the C++ standard

library to use.
 - This is currently useful for testing libc++; you can now use 'clang++
   -stdlib=libc++ t.cpp' to compile using it if installed.

 - In the future could also be used to select other standard library choices if
   alternatives become available (for example, to use an alternate C library).

llvm-svn: 113891

1 files changed, 19 insertions, 0 deletions

diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 0f630464093..337ea4e8f94 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -175,6 +175,16 @@ std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args) const {
 }
 
 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
+  if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
+    llvm::StringRef Value = A->getValue(Args);
+    if (Value == "libc++")
+      return ToolChain::CST_Libcxx;
+    if (Value == "libstdc++")
+      return ToolChain::CST_Libstdcxx;
+    getDriver().Diag(clang::diag::err_drv_invalid_stdlib_name)
+      << A->getAsString(Args);
+  }
+
   return ToolChain::CST_Libstdcxx;
 }
 
@@ -183,6 +193,11 @@ void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &Args,
   CXXStdlibType Type = GetCXXStdlibType(Args);
 
   switch (Type) {
+  case ToolChain::CST_Libcxx:
+    CmdArgs.push_back("-cxx-system-include");
+    CmdArgs.push_back("/usr/include/c++/v1");
+    break;
+
   case ToolChain::CST_Libstdcxx:
     // Currently handled by the mass of goop in InitHeaderSearch.
     break;
@@ -194,6 +209,10 @@ void ToolChain::AddClangCXXStdlibLibArgs(const ArgList &Args,
   CXXStdlibType Type = GetCXXStdlibType(Args);
 
   switch (Type) {
+  case ToolChain::CST_Libcxx:
+    CmdArgs.push_back("-lc++");
+    break;
+
   case ToolChain::CST_Libstdcxx:
     CmdArgs.push_back("-lstdc++");
     break;