1 files changed, 22 insertions, 6 deletions
diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index d39bfaa4bec..5df96ce54e3 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -3849,6 +3849,25 @@ void Linux::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
 }
 
 
+static std::string DetectLibcxxIncludePath(StringRef base) {
+  std::error_code EC;
+  int MaxVersion = 0;
+  std::string MaxVersionString = "";
+  for (llvm::sys::fs::directory_iterator LI(base, EC), LE; !EC && LI != LE;
+       LI = LI.increment(EC)) {
+    StringRef VersionText = llvm::sys::path::filename(LI->path());
+    int Version;
+    if (VersionText[0] == 'v' &&
+        !VersionText.slice(1, StringRef::npos).getAsInteger(10, Version)) {
+      if (Version > MaxVersion) {
+        MaxVersion = Version;
+        MaxVersionString = VersionText;
+      }
+    }
+  }
+  return MaxVersion ? (base + "/" + MaxVersionString).str() : "";
+}
+
 void Linux::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
                                          ArgStringList &CC1Args) const {
   if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
@@ -3858,17 +3877,14 @@ void Linux::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
   // Check if libc++ has been enabled and provide its include paths if so.
   if (GetCXXStdlibType(DriverArgs) == ToolChain::CST_Libcxx) {
     const std::string LibCXXIncludePathCandidates[] = {
-        // The primary location is within the Clang installation.
-        // FIXME: We shouldn't hard code 'v1' here to make Clang future proof to
-        // newer ABI versions.
-        getDriver().Dir + "/../include/c++/v1",
+        DetectLibcxxIncludePath(getDriver().Dir + "/../include/c++"),
 
         // We also check the system as for a long time this is the only place
         // Clang looked.
         // FIXME: We should really remove this. It doesn't make any sense.
-        getDriver().SysRoot + "/usr/include/c++/v1"};
+        DetectLibcxxIncludePath(getDriver().SysRoot + "/usr/include/c++")};
     for (const auto &IncludePath : LibCXXIncludePathCandidates) {
-      if (!getVFS().exists(IncludePath))
+      if (IncludePath.empty() || !getVFS().exists(IncludePath))
         continue;
       // Add the first candidate that exists.
       addSystemInclude(DriverArgs, CC1Args, IncludePath);