--- llvm-11.0.0.src/tools/clang/include/clang/Driver/Distro.h.alt-triple	2020-10-07 10:10:48.000000000 +0000
+++ llvm-11.0.0.src/tools/clang/include/clang/Driver/Distro.h	2020-10-13 13:41:28.675033578 +0000
@@ -26,6 +26,7 @@ public:
     // NB: Releases of a particular Linux distro should be kept together
     // in this enum, because some tests are done by integer comparison against
     // the first and last known member in the family, e.g. IsRedHat().
+    ALTLinux,
     AlpineLinux,
     ArchLinux,
     DebianLenny,
--- llvm-11.0.0.src/tools/clang/lib/Driver/Distro.cpp.alt-triple	2020-10-07 10:10:48.000000000 +0000
+++ llvm-11.0.0.src/tools/clang/lib/Driver/Distro.cpp	2020-10-13 13:41:28.675033578 +0000
@@ -36,6 +36,7 @@ static Distro::DistroType DetectOsRelease(llvm::vfs::FileSystem &VFS) {
   for (StringRef Line : Lines)
     if (Version == Distro::UnknownDistro && Line.startswith("ID="))
       Version = llvm::StringSwitch<Distro::DistroType>(Line.substr(3))
+                    .Case("altlinux", Distro::ALTLinux)
                     .Case("fedora", Distro::Fedora)
                     .Case("gentoo", Distro::Gentoo)
                     .Case("arch", Distro::ArchLinux)
--- llvm-11.0.0.src/tools/clang/lib/Driver/ToolChains/Gnu.cpp.alt-triple	2020-10-07 10:10:48.000000000 +0000
+++ llvm-11.0.0.src/tools/clang/lib/Driver/ToolChains/Gnu.cpp	2020-10-13 13:45:46.630074051 +0000
@@ -2049,7 +2049,7 @@ void Generic_GCC::GCCInstallationDetecto
   static const char *const AArch64LibDirs[] = {"/lib64", "/lib"};
   static const char *const AArch64Triples[] = {
       "aarch64-none-linux-gnu", "aarch64-linux-gnu", "aarch64-redhat-linux",
-      "aarch64-suse-linux", "aarch64-linux-android"};
+      "aarch64-suse-linux", "aarch64-linux-android", "aarch64-alt-linux"};
   static const char *const AArch64beLibDirs[] = {"/lib"};
   static const char *const AArch64beTriples[] = {"aarch64_be-none-linux-gnu",
                                                  "aarch64_be-linux-gnu"};
@@ -2060,7 +2060,8 @@ void Generic_GCC::GCCInstallationDetecto
   static const char *const ARMHFTriples[] = {"arm-linux-gnueabihf",
                                              "armv7hl-redhat-linux-gnueabi",
                                              "armv6hl-suse-linux-gnueabi",
-                                             "armv7hl-suse-linux-gnueabi"};
+                                             "armv7hl-suse-linux-gnueabi",
+                                             "armh-alt-linux-gnueabi"};
   static const char *const ARMebLibDirs[] = {"/lib"};
   static const char *const ARMebTriples[] = {"armeb-linux-gnueabi",
                                              "armeb-linux-androideabi"};
@@ -2077,7 +2078,8 @@ void Generic_GCC::GCCInstallationDetecto
       "x86_64-redhat-linux",    "x86_64-suse-linux",
       "x86_64-manbo-linux-gnu", "x86_64-linux-gnu",
       "x86_64-slackware-linux", "x86_64-unknown-linux",
-      "x86_64-amazon-linux",    "x86_64-linux-android"};
+      "x86_64-amazon-linux",    "x86_64-linux-android",
+      "x86_64-alt-linux"};
   static const char *const X32LibDirs[] = {"/libx32"};
   static const char *const X86LibDirs[] = {"/lib32", "/lib"};
   static const char *const X86Triples[] = {
@@ -2086,7 +2088,7 @@ void Generic_GCC::GCCInstallationDetecto
       "i586-redhat-linux",    "i386-redhat-linux",     "i586-suse-linux",
       "i486-slackware-linux", "i686-montavista-linux", "i586-linux-gnu",
       "i686-linux-android",   "i386-gnu",              "i486-gnu",
-      "i586-gnu",             "i686-gnu"};
+      "i586-gnu",             "i686-gnu",              "i586-alt-linux"};
 
   static const char *const MIPSLibDirs[] = {"/lib"};
   static const char *const MIPSTriples[] = {
@@ -2095,7 +2097,7 @@ void Generic_GCC::GCCInstallationDetecto
   static const char *const MIPSELLibDirs[] = {"/lib"};
   static const char *const MIPSELTriples[] = {
       "mipsel-linux-gnu", "mips-img-linux-gnu", "mipsisa32r6el-linux-gnu",
-      "mipsel-linux-android"};
+      "mipsel-linux-android", "mipsel-alt-linux", "mipsel-alt-linux-gnu"};
 
   static const char *const MIPS64LibDirs[] = {"/lib64", "/lib"};
   static const char *const MIPS64Triples[] = {
@@ -2107,7 +2109,7 @@ void Generic_GCC::GCCInstallationDetecto
       "mips64el-linux-gnu",      "mips-mti-linux-gnu",
       "mips-img-linux-gnu",      "mips64el-linux-gnuabi64",
       "mipsisa64r6el-linux-gnu", "mipsisa64r6el-linux-gnuabi64",
-      "mips64el-linux-android"};
+      "mips64el-linux-android", "mips64el-alt-linux-gnuabi64"};
 
   static const char *const MIPSN32LibDirs[] = {"/lib32"};
   static const char *const MIPSN32Triples[] = {"mips64-linux-gnuabin32",
@@ -2132,7 +2134,7 @@ void Generic_GCC::GCCInstallationDetecto
   static const char *const PPC64LELibDirs[] = {"/lib64", "/lib"};
   static const char *const PPC64LETriples[] = {
       "powerpc64le-linux-gnu", "powerpc64le-unknown-linux-gnu",
       "powerpc64le-none-linux-gnu", "powerpc64le-suse-linux",
-      "ppc64le-redhat-linux"};
+      "ppc64le-redhat-linux", "ppc64le-alt-linux"};
 
   static const char *const RISCV32LibDirs[] = {"/lib32", "/lib"};
   static const char *const RISCV32Triples[] = {"riscv32-unknown-linux-gnu",
@@ -2142,6 +2144,7 @@ void Generic_GCC::GCCInstallationDetecto
   static const char *const RISCV64Triples[] = {"riscv64-unknown-linux-gnu",
                                                "riscv64-linux-gnu",
                                                "riscv64-unknown-elf",
+                                               "riscv64-alt-linux",
                                                "riscv64-redhat-linux",
                                                "riscv64-suse-linux"};