Index: clang/lib/Driver/ToolChains/Gnu.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Gnu.cpp
+++ clang/lib/Driver/ToolChains/Gnu.cpp
@@ -2130,17 +2130,31 @@
   // and gcc-toolsets.
   if (SysRoot.empty() && TargetTriple.getOS() == llvm::Triple::Linux &&
       D.getVFS().exists("/opt/rh")) {
-    Prefixes.push_back("/opt/rh/gcc-toolset-11/root/usr");
-    Prefixes.push_back("/opt/rh/gcc-toolset-10/root/usr");
-    Prefixes.push_back("/opt/rh/devtoolset-11/root/usr");
-    Prefixes.push_back("/opt/rh/devtoolset-10/root/usr");
-    Prefixes.push_back("/opt/rh/devtoolset-9/root/usr");
-    Prefixes.push_back("/opt/rh/devtoolset-8/root/usr");
-    Prefixes.push_back("/opt/rh/devtoolset-7/root/usr");
-    Prefixes.push_back("/opt/rh/devtoolset-6/root/usr");
-    Prefixes.push_back("/opt/rh/devtoolset-4/root/usr");
-    Prefixes.push_back("/opt/rh/devtoolset-3/root/usr");
-    Prefixes.push_back("/opt/rh/devtoolset-2/root/usr");
+    // Find the directory in /opt/rh/ starting with gcc-toolset-* or
+    // devtoolset-* with the highest version number and add that
+    // one to our prefixes.
+    std::string ChosenToolsetDir;
+    unsigned ChosenToolsetVersion = 0;
+    std::error_code EC;
+    for (llvm::vfs::directory_iterator LI = D.getVFS().dir_begin("/opt/rh", EC),
+                                       LE;
+         !EC && LI != LE; LI = LI.increment(EC)) {
+      StringRef ToolsetDir = llvm::sys::path::filename(LI->path());
+      unsigned ToolsetVersion;
+      if ((!ToolsetDir.startswith("gcc-toolset-") &&
+           !ToolsetDir.startswith("devtoolset-")) ||
+          ToolsetDir.substr(ToolsetDir.rfind('-') + 1)
+              .getAsInteger(10, ToolsetVersion))
+        continue;
+
+      if (ToolsetVersion > ChosenToolsetVersion) {
+        ChosenToolsetVersion = ToolsetVersion;
+        ChosenToolsetDir = "/opt/rh/" + ToolsetDir.str();
+      }
+    }
+
+    if (ChosenToolsetVersion > 0)
+      Prefixes.push_back(ChosenToolsetDir);
   }
 
   // Fall back to /usr which is used by most non-Solaris systems.
Index: clang/unittests/Driver/ToolChainTest.cpp
===================================================================
--- clang/unittests/Driver/ToolChainTest.cpp
+++ clang/unittests/Driver/ToolChainTest.cpp
@@ -18,6 +18,7 @@
 #include "clang/Driver/Driver.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/MC/TargetRegistry.h"
+#include "llvm/Support/Host.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Support/raw_ostream.h"
@@ -610,4 +611,94 @@
   DiagConsumer->clear();
 }
 
+TEST(ToolChainTest, Toolsets) {
+  // Ignore this test on Windows hosts.
+  llvm::Triple Host(llvm::sys::getProcessTriple());
+  if (Host.isOSWindows())
+    GTEST_SKIP();
+
+  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
+  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
+
+  // Check (newer) GCC toolset installation.
+  {
+    IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
+        new llvm::vfs::InMemoryFileSystem);
+
+    // These should be ignored.
+    InMemoryFileSystem->addFile("/opt/rh/gcc-toolset-2", 0,
+                                llvm::MemoryBuffer::getMemBuffer("\n"));
+    InMemoryFileSystem->addFile("/opt/rh/gcc-toolset-", 0,
+                                llvm::MemoryBuffer::getMemBuffer("\n"));
+    InMemoryFileSystem->addFile("/opt/rh/gcc-toolset--", 0,
+                                llvm::MemoryBuffer::getMemBuffer("\n"));
+    InMemoryFileSystem->addFile("/opt/rh/gcc-toolset--1", 0,
+                                llvm::MemoryBuffer::getMemBuffer("\n"));
+
+    // File needed for GCC installation detection.
+    InMemoryFileSystem->addFile(
+        "/opt/rh/gcc-toolset-12/lib/gcc/x86_64-redhat-linux/11/crtbegin.o", 0,
+        llvm::MemoryBuffer::getMemBuffer("\n"));
+
+    DiagnosticsEngine Diags(DiagID, &*DiagOpts, new SimpleDiagnosticConsumer);
+    Driver TheDriver("/bin/clang", "x86_64-redhat-linux", Diags,
+                     "clang LLVM compiler", InMemoryFileSystem);
+    std::unique_ptr<Compilation> C(
+        TheDriver.BuildCompilation({"--gcc-toolchain="}));
+    ASSERT_TRUE(C);
+    std::string S;
+    {
+      llvm::raw_string_ostream OS(S);
+      C->getDefaultToolChain().printVerboseInfo(OS);
+    }
+    EXPECT_EQ("Found candidate GCC installation: "
+              "/opt/rh/gcc-toolset-12/lib/gcc/x86_64-redhat-linux/11\n"
+              "Selected GCC installation: "
+              "/opt/rh/gcc-toolset-12/lib/gcc/x86_64-redhat-linux/11\n"
+              "Candidate multilib: .;@m64\n"
+              "Selected multilib: .;@m64\n",
+              S);
+  }
+
+  // And older devtoolset.
+  {
+    IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
+        new llvm::vfs::InMemoryFileSystem);
+
+    // These should be ignored.
+    InMemoryFileSystem->addFile("/opt/rh/devtoolset-2", 0,
+                                llvm::MemoryBuffer::getMemBuffer("\n"));
+    InMemoryFileSystem->addFile("/opt/rh/devtoolset-", 0,
+                                llvm::MemoryBuffer::getMemBuffer("\n"));
+    InMemoryFileSystem->addFile("/opt/rh/devtoolset--", 0,
+                                llvm::MemoryBuffer::getMemBuffer("\n"));
+    InMemoryFileSystem->addFile("/opt/rh/devtoolset--1", 0,
+                                llvm::MemoryBuffer::getMemBuffer("\n"));
+
+    // File needed for GCC installation detection.
+    InMemoryFileSystem->addFile(
+        "/opt/rh/devtoolset-12/lib/gcc/x86_64-redhat-linux/11/crtbegin.o", 0,
+        llvm::MemoryBuffer::getMemBuffer("\n"));
+
+    DiagnosticsEngine Diags(DiagID, &*DiagOpts, new SimpleDiagnosticConsumer);
+    Driver TheDriver("/bin/clang", "x86_64-redhat-linux", Diags,
+                     "clang LLVM compiler", InMemoryFileSystem);
+    std::unique_ptr<Compilation> C(
+        TheDriver.BuildCompilation({"--gcc-toolchain="}));
+    ASSERT_TRUE(C);
+    std::string S;
+    {
+      llvm::raw_string_ostream OS(S);
+      C->getDefaultToolChain().printVerboseInfo(OS);
+    }
+    EXPECT_EQ("Found candidate GCC installation: "
+              "/opt/rh/devtoolset-12/lib/gcc/x86_64-redhat-linux/11\n"
+              "Selected GCC installation: "
+              "/opt/rh/devtoolset-12/lib/gcc/x86_64-redhat-linux/11\n"
+              "Candidate multilib: .;@m64\n"
+              "Selected multilib: .;@m64\n",
+              S);
+  }
+}
+
 } // end anonymous namespace.