1 files changed, 23 insertions, 2 deletions
diff --git a/contrib/llvm-project/clang/lib/Driver/ToolChains/MinGW.cpp b/contrib/llvm-project/clang/lib/Driver/ToolChains/MinGW.cpp
index 65512f16357d..18fc9d4b6807 100644
--- a/contrib/llvm-project/clang/lib/Driver/ToolChains/MinGW.cpp
+++ b/contrib/llvm-project/clang/lib/Driver/ToolChains/MinGW.cpp
@@ -471,12 +471,23 @@ findClangRelativeSysroot(const Driver &D, const llvm::Triple &LiteralTriple,
   return make_error_code(std::errc::no_such_file_or_directory);
 }
 
+static bool looksLikeMinGWSysroot(const std::string &Directory) {
+  StringRef Sep = llvm::sys::path::get_separator();
+  if (!llvm::sys::fs::exists(Directory + Sep + "include" + Sep + "_mingw.h"))
+    return false;
+  if (!llvm::sys::fs::exists(Directory + Sep + "lib" + Sep + "libkernel32.a"))
+    return false;
+  return true;
+}
+
 toolchains::MinGW::MinGW(const Driver &D, const llvm::Triple &Triple,
                          const ArgList &Args)
     : ToolChain(D, Triple, Args), CudaInstallation(D, Triple, Args),
       RocmInstallation(D, Triple, Args) {
   getProgramPaths().push_back(getDriver().getInstalledDir());
 
+  std::string InstallBase =
+      std::string(llvm::sys::path::parent_path(getDriver().getInstalledDir()));
   // The sequence for detecting a sysroot here should be kept in sync with
   // the testTriple function below.
   llvm::Triple LiteralTriple = getLiteralTriple(D, getTriple());
@@ -487,13 +498,17 @@ toolchains::MinGW::MinGW(const Driver &D, const llvm::Triple &Triple,
   else if (llvm::ErrorOr<std::string> TargetSubdir = findClangRelativeSysroot(
                getDriver(), LiteralTriple, getTriple(), SubdirName))
     Base = std::string(llvm::sys::path::parent_path(TargetSubdir.get()));
+  // If the install base of Clang seems to have mingw sysroot files directly
+  // in the toplevel include and lib directories, use this as base instead of
+  // looking for a triple prefixed GCC in the path.
+  else if (looksLikeMinGWSysroot(InstallBase))
+    Base = InstallBase;
   else if (llvm::ErrorOr<std::string> GPPName =
                findGcc(LiteralTriple, getTriple()))
     Base = std::string(llvm::sys::path::parent_path(
         llvm::sys::path::parent_path(GPPName.get())));
   else
-    Base = std::string(
-        llvm::sys::path::parent_path(getDriver().getInstalledDir()));
+    Base = InstallBase;
 
   Base += llvm::sys::path::get_separator();
   findGccLibDir(LiteralTriple);
@@ -778,9 +793,15 @@ static bool testTriple(const Driver &D, const llvm::Triple &Triple,
   if (D.SysRoot.size())
     return true;
   llvm::Triple LiteralTriple = getLiteralTriple(D, Triple);
+  std::string InstallBase =
+      std::string(llvm::sys::path::parent_path(D.getInstalledDir()));
   if (llvm::ErrorOr<std::string> TargetSubdir =
           findClangRelativeSysroot(D, LiteralTriple, Triple, SubdirName))
     return true;
+  // If the install base itself looks like a mingw sysroot, we'll use that
+  // - don't use any potentially unrelated gcc to influence what triple to use.
+  if (looksLikeMinGWSysroot(InstallBase))
+    return false;
   if (llvm::ErrorOr<std::string> GPPName = findGcc(LiteralTriple, Triple))
     return true;
   // If we neither found a colocated sysroot or a matching gcc executable,