diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index f0c7f05..ab56440 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -77,6 +77,8 @@ def ccc_debug_Group : OptionGroup<"<clang debug/development internal options>">,
   Group<ccc_Group>, HelpText<"DEBUG/DEVELOPMENT OPTIONS">;
 
 class CCCDriverOpt : Group<ccc_driver_Group>, Flags<[DriverOption, HelpHidden]>;
+def ccc_gcc_toolchain : Separate<"-ccc-gcc-toolchain">, CCCDriverOpt,
+  HelpText<"Use the gcc toolchaing at the given directory">;
 def ccc_cxx : Flag<"-ccc-cxx">, CCCDriverOpt,
   HelpText<"Act as a C++ driver">;
 def ccc_echo : Flag<"-ccc-echo">, CCCDriverOpt,
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index 26ceb32..f18555a 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -1632,7 +1632,7 @@ const ToolChain &Driver::getToolChain(const ArgList &Args,
   if (!TC) {
     switch (Target.getOS()) {
     case llvm::Triple::AuroraUX:
-      TC = new toolchains::AuroraUX(*this, Target);
+      TC = new toolchains::AuroraUX(*this, Target, Args);
       break;
     case llvm::Triple::Darwin:
     case llvm::Triple::MacOSX:
@@ -1643,28 +1643,28 @@ const ToolChain &Driver::getToolChain(const ArgList &Args,
           Target.getArch() == llvm::Triple::thumb)
         TC = new toolchains::DarwinClang(*this, Target);
       else
-        TC = new toolchains::Darwin_Generic_GCC(*this, Target);
+        TC = new toolchains::Darwin_Generic_GCC(*this, Target, Args);
       break;
     case llvm::Triple::DragonFly:
-      TC = new toolchains::DragonFly(*this, Target);
+      TC = new toolchains::DragonFly(*this, Target, Args);
       break;
     case llvm::Triple::OpenBSD:
-      TC = new toolchains::OpenBSD(*this, Target);
+      TC = new toolchains::OpenBSD(*this, Target, Args);
       break;
     case llvm::Triple::NetBSD:
-      TC = new toolchains::NetBSD(*this, Target);
+      TC = new toolchains::NetBSD(*this, Target, Args);
       break;
     case llvm::Triple::FreeBSD:
-      TC = new toolchains::FreeBSD(*this, Target);
+      TC = new toolchains::FreeBSD(*this, Target, Args);
       break;
     case llvm::Triple::Minix:
-      TC = new toolchains::Minix(*this, Target);
+      TC = new toolchains::Minix(*this, Target, Args);
       break;
     case llvm::Triple::Linux:
       if (Target.getArch() == llvm::Triple::hexagon)
         TC = new toolchains::Hexagon_TC(*this, Target);
       else
-        TC = new toolchains::Linux(*this, Target);
+        TC = new toolchains::Linux(*this, Target, Args);
       break;
     case llvm::Triple::Win32:
       TC = new toolchains::Windows(*this, Target);
@@ -1678,7 +1678,7 @@ const ToolChain &Driver::getToolChain(const ArgList &Args,
         break;
       }
 
-      TC = new toolchains::Generic_GCC(*this, Target);
+      TC = new toolchains::Generic_GCC(*this, Target, Args);
       break;
     }
   }
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index 8c7158f..c6eb59b 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -1091,6 +1091,13 @@ bool Generic_GCC::GCCVersion::operator<(const GCCVersion &RHS) const {
   return false;
 }
 
+static StringRef getGCCToolchainDir(const ArgList &Args) {
+  const Arg *A = Args.getLastArg(options::OPT_ccc_gcc_toolchain);
+  if (A)
+    return A->getValue(Args);
+  return GCC_INSTALL_PREFIX;
+}
+
 /// \brief Construct a GCCInstallationDetector from the driver.
 ///
 /// This performs all of the autodetection and sets up the various paths.
@@ -1102,7 +1109,8 @@ bool Generic_GCC::GCCVersion::operator<(const GCCVersion &RHS) const {
 /// triple.
 Generic_GCC::GCCInstallationDetector::GCCInstallationDetector(
     const Driver &D,
-    const llvm::Triple &TargetTriple)
+    const llvm::Triple &TargetTriple,
+    const ArgList &Args)
     : IsValid(false) {
   llvm::Triple MultiarchTriple
     = TargetTriple.isArch32Bit() ? TargetTriple.get64BitArchVariant()
@@ -1122,12 +1130,12 @@ Generic_GCC::GCCInstallationDetector::GCCInstallationDetector(
   SmallVector<std::string, 8> Prefixes(D.PrefixDirs.begin(),
                                        D.PrefixDirs.end());
 
-  SmallString<128> CxxInstallRoot(GCC_INSTALL_PREFIX);
-  if (CxxInstallRoot != "") {
-    if (CxxInstallRoot.back() == '/')
-      llvm::sys::path::remove_filename(CxxInstallRoot); // remove the /
+  StringRef GCCToolchainDir = getGCCToolchainDir(Args);
+  if (GCCToolchainDir != "") {
+    if (GCCToolchainDir.back() == '/')
+      GCCToolchainDir = GCCToolchainDir.drop_back(); // remove the /
 
-    Prefixes.push_back(CxxInstallRoot.str());
+    Prefixes.push_back(GCCToolchainDir);
   } else {
     Prefixes.push_back(D.SysRoot);
     Prefixes.push_back(D.SysRoot + "/usr");
@@ -1360,8 +1368,9 @@ void Generic_GCC::GCCInstallationDetector::ScanLibDirForGCCTriple(
   }
 }
 
-Generic_GCC::Generic_GCC(const Driver &D, const llvm::Triple& Triple)
-  : ToolChain(D, Triple), GCCInstallation(getDriver(), Triple) {
+Generic_GCC::Generic_GCC(const Driver &D, const llvm::Triple& Triple,
+                         const ArgList &Args)
+  : ToolChain(D, Triple), GCCInstallation(getDriver(), Triple, Args) {
   getProgramPaths().push_back(getDriver().getInstalledDir());
   if (getDriver().getInstalledDir() != getDriver().Dir)
     getProgramPaths().push_back(getDriver().Dir);
@@ -1554,8 +1563,8 @@ Tool &TCEToolChain::SelectTool(const Compilation &C,
 
 /// OpenBSD - OpenBSD tool chain which can call as(1) and ld(1) directly.
 
-OpenBSD::OpenBSD(const Driver &D, const llvm::Triple& Triple)
-  : Generic_ELF(D, Triple) {
+OpenBSD::OpenBSD(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)
+  : Generic_ELF(D, Triple, Args) {
   getFilePaths().push_back(getDriver().Dir + "/../lib");
   getFilePaths().push_back("/usr/lib");
 }
@@ -1594,8 +1603,8 @@ Tool &OpenBSD::SelectTool(const Compilation &C, const JobAction &JA,
 
 /// FreeBSD - FreeBSD tool chain which can call as(1) and ld(1) directly.
 
-FreeBSD::FreeBSD(const Driver &D, const llvm::Triple& Triple)
-  : Generic_ELF(D, Triple) {
+FreeBSD::FreeBSD(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)
+  : Generic_ELF(D, Triple, Args) {
 
   // When targeting 32-bit platforms, look for '/usr/lib32/crt1.o' and fall
   // back to '/usr/lib' if it doesn't exist.
@@ -1640,8 +1649,8 @@ Tool &FreeBSD::SelectTool(const Compilation &C, const JobAction &JA,
 
 /// NetBSD - NetBSD tool chain which can call as(1) and ld(1) directly.
 
-NetBSD::NetBSD(const Driver &D, const llvm::Triple& Triple)
-  : Generic_ELF(D, Triple) {
+NetBSD::NetBSD(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)
+  : Generic_ELF(D, Triple, Args) {
 
   if (getDriver().UseStdLib) {
     // When targeting a 32-bit platform, try the special directory used on
@@ -1690,8 +1699,8 @@ Tool &NetBSD::SelectTool(const Compilation &C, const JobAction &JA,
 
 /// Minix - Minix tool chain which can call as(1) and ld(1) directly.
 
-Minix::Minix(const Driver &D, const llvm::Triple& Triple)
-  : Generic_ELF(D, Triple) {
+Minix::Minix(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)
+  : Generic_ELF(D, Triple, Args) {
   getFilePaths().push_back(getDriver().Dir + "/../lib");
   getFilePaths().push_back("/usr/lib");
 }
@@ -1721,8 +1730,8 @@ Tool &Minix::SelectTool(const Compilation &C, const JobAction &JA,
 
 /// AuroraUX - AuroraUX tool chain which can call as(1) and ld(1) directly.
 
-AuroraUX::AuroraUX(const Driver &D, const llvm::Triple& Triple)
-  : Generic_GCC(D, Triple) {
+AuroraUX::AuroraUX(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)
+  : Generic_GCC(D, Triple, Args) {
 
   getProgramPaths().push_back(getDriver().getInstalledDir());
   if (getDriver().getInstalledDir() != getDriver().Dir)
@@ -1927,8 +1936,8 @@ static void addPathIfExists(Twine Path, ToolChain::path_list &Paths) {
   if (llvm::sys::fs::exists(Path)) Paths.push_back(Path.str());
 }
 
-Linux::Linux(const Driver &D, const llvm::Triple &Triple)
-  : Generic_ELF(D, Triple) {
+Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
+  : Generic_ELF(D, Triple, Args) {
   llvm::Triple::ArchType Arch = Triple.getArch();
   const std::string &SysRoot = getDriver().SysRoot;
 
@@ -2213,8 +2222,8 @@ void Linux::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
 
 /// DragonFly - DragonFly tool chain which can call as(1) and ld(1) directly.
 
-DragonFly::DragonFly(const Driver &D, const llvm::Triple& Triple)
-  : Generic_ELF(D, Triple) {
+DragonFly::DragonFly(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)
+  : Generic_ELF(D, Triple, Args) {
 
   // Path mangling to find libexec
   getProgramPaths().push_back(getDriver().getInstalledDir());
diff --git a/lib/Driver/ToolChains.h b/lib/Driver/ToolChains.h
index c454db5..ba219d8 100644
--- a/lib/Driver/ToolChains.h
+++ b/lib/Driver/ToolChains.h
@@ -79,7 +79,8 @@ protected:
     GCCVersion Version;
 
   public:
-    GCCInstallationDetector(const Driver &D, const llvm::Triple &TargetTriple);
+    GCCInstallationDetector(const Driver &D, const llvm::Triple &TargetTriple,
+                            const ArgList &Args);
 
     /// \brief Check whether we detected a valid GCC install.
     bool isValid() const { return IsValid; }
@@ -119,7 +120,7 @@ protected:
   mutable llvm::DenseMap<unsigned, Tool*> Tools;
 
 public:
-  Generic_GCC(const Driver &D, const llvm::Triple& Triple);
+  Generic_GCC(const Driver &D, const llvm::Triple& Triple, const ArgList &Args);
   ~Generic_GCC();
 
   virtual Tool &SelectTool(const Compilation &C, const JobAction &JA,
@@ -419,8 +420,8 @@ public:
 /// Darwin_Generic_GCC - Generic Darwin tool chain using gcc.
 class LLVM_LIBRARY_VISIBILITY Darwin_Generic_GCC : public Generic_GCC {
 public:
-  Darwin_Generic_GCC(const Driver &D, const llvm::Triple& Triple)
-    : Generic_GCC(D, Triple) {}
+  Darwin_Generic_GCC(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)
+    : Generic_GCC(D, Triple, Args) {}
 
   std::string ComputeEffectiveClangTriple(const ArgList &Args,
                                           types::ID InputType) const;
@@ -431,8 +432,8 @@ public:
 class LLVM_LIBRARY_VISIBILITY Generic_ELF : public Generic_GCC {
   virtual void anchor();
 public:
-  Generic_ELF(const Driver &D, const llvm::Triple& Triple)
-    : Generic_GCC(D, Triple) {}
+  Generic_ELF(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)
+    : Generic_GCC(D, Triple, Args) {}
 
   virtual bool IsIntegratedAssemblerDefault() const {
     // Default integrated assembler to on for x86.
@@ -443,7 +444,7 @@ public:
 
 class LLVM_LIBRARY_VISIBILITY AuroraUX : public Generic_GCC {
 public:
-  AuroraUX(const Driver &D, const llvm::Triple& Triple);
+  AuroraUX(const Driver &D, const llvm::Triple& Triple, const ArgList &Args);
 
   virtual Tool &SelectTool(const Compilation &C, const JobAction &JA,
                            const ActionList &Inputs) const;
@@ -451,7 +452,7 @@ public:
 
 class LLVM_LIBRARY_VISIBILITY OpenBSD : public Generic_ELF {
 public:
-  OpenBSD(const Driver &D, const llvm::Triple& Triple);
+  OpenBSD(const Driver &D, const llvm::Triple& Triple, const ArgList &Args);
 
   virtual Tool &SelectTool(const Compilation &C, const JobAction &JA,
                            const ActionList &Inputs) const;
@@ -459,7 +460,7 @@ public:
 
 class LLVM_LIBRARY_VISIBILITY FreeBSD : public Generic_ELF {
 public:
-  FreeBSD(const Driver &D, const llvm::Triple& Triple);
+  FreeBSD(const Driver &D, const llvm::Triple& Triple, const ArgList &Args);
 
   virtual Tool &SelectTool(const Compilation &C, const JobAction &JA,
                            const ActionList &Inputs) const;
@@ -467,7 +468,7 @@ public:
 
 class LLVM_LIBRARY_VISIBILITY NetBSD : public Generic_ELF {
 public:
-  NetBSD(const Driver &D, const llvm::Triple& Triple);
+  NetBSD(const Driver &D, const llvm::Triple& Triple, const ArgList &Args);
 
   virtual Tool &SelectTool(const Compilation &C, const JobAction &JA,
                            const ActionList &Inputs) const;
@@ -475,7 +476,7 @@ public:
 
 class LLVM_LIBRARY_VISIBILITY Minix : public Generic_ELF {
 public:
-  Minix(const Driver &D, const llvm::Triple& Triple);
+  Minix(const Driver &D, const llvm::Triple& Triple, const ArgList &Args);
 
   virtual Tool &SelectTool(const Compilation &C, const JobAction &JA,
                            const ActionList &Inputs) const;
@@ -483,7 +484,7 @@ public:
 
 class LLVM_LIBRARY_VISIBILITY DragonFly : public Generic_ELF {
 public:
-  DragonFly(const Driver &D, const llvm::Triple& Triple);
+  DragonFly(const Driver &D, const llvm::Triple& Triple, const ArgList &Args);
 
   virtual Tool &SelectTool(const Compilation &C, const JobAction &JA,
                            const ActionList &Inputs) const;
@@ -491,7 +492,7 @@ public:
 
 class LLVM_LIBRARY_VISIBILITY Linux : public Generic_ELF {
 public:
-  Linux(const Driver &D, const llvm::Triple& Triple);
+  Linux(const Driver &D, const llvm::Triple& Triple, const ArgList &Args);
 
   virtual bool HasNativeLLVMSupport() const;
 
diff --git a/test/Driver/ccc-gcc-toolchain.cpp b/test/Driver/ccc-gcc-toolchain.cpp
new file mode 100644
index 0000000..ca0af04
--- /dev/null
+++ b/test/Driver/ccc-gcc-toolchain.cpp
@@ -0,0 +1,26 @@
+// Test that ccc-gcc-toolchain option is working correctly 
+//
+// RUN: %clangxx -no-canonical-prefixes %s -### -o %t 2>&1 \
+// RUN:     -target i386-unknown-linux \
+// RUN:     -ccc-gcc-toolchain %S/Inputs/ubuntu_11.04_multiarch_tree/usr \
+// RUN:   | FileCheck %s
+
+// CHECK: "-internal-isystem"
+// CHECK: "[[TOOLCHAIN:.*]]/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5/../../../../../include/c++/4.5"
+// CHECK: "-internal-isystem"
+// CHECK: "[[TOOLCHAIN]]/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5/../../../../../include/c++/4.5/i686-linux-gnu"
+// CHECK: "-internal-isystem"
+// CHECK: "[[TOOLCHAIN]]/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5/../../../../../include/c++/4.5/backward"
+// CHECK: "-internal-isystem"
+// CHECK: "/usr/local/include"
+// CHECK: "-internal-isystem"
+// CHECK: "/Users/espindola/llvm/build/bin/./../lib/clang/3.1/include"
+// CHECK: "-internal-externc-isystem"
+// CHECK: "/include"
+// CHECK: "-internal-externc-isystem"
+// CHECK: "/usr/include"
+// CHECK: "/{{.*}}/ld"
+// CHECK: "[[TOOLCHAIN]]/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5/crtbegin.o"
+// CHECK: "-L[[TOOLCHAIN]]/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5"
+// CHECK: "-L[[TOOLCHAIN]]/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5/../../../.."
+// CHECK: "-L/usr/lib"