6 files changed, 29 insertions, 22 deletions
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 71c5280..51618d1 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -2540,10 +2540,14 @@ bool Driver::HandleImmediateArgs(Compilation &C) {
   }
 
   if (C.getArgs().hasArg(options::OPT_print_runtime_dir)) {
-    if (std::optional<std::string> RuntimePath = TC.getRuntimePath())
-      llvm::outs() << *RuntimePath << '\n';
-    else
-      llvm::outs() << TC.getCompilerRTPath() << '\n';
+    for (auto RuntimePath :
+         {TC.getRuntimePath(), std::make_optional(TC.getCompilerRTPath())}) {
+      if (RuntimePath && getVFS().exists(*RuntimePath)) {
+        llvm::outs() << *RuntimePath << '\n';
+        return false;
+      }
+    }
+    llvm::outs() << "(runtime dir is not present)" << '\n';
     return false;
   }
 
diff --git a/clang/lib/Driver/ToolChains/Arch/M68k.cpp b/clang/lib/Driver/ToolChains/Arch/M68k.cpp
index 1037c0e..708ec84 100644
--- a/clang/lib/Driver/ToolChains/Arch/M68k.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/M68k.cpp
@@ -36,12 +36,12 @@ std::string m68k::getM68kTargetCPU(const ArgList &Args) {
       return "generic";
 
     return llvm::StringSwitch<std::string>(CPUName)
-        .Cases("m68000", "68000", "M68000")
-        .Cases("m68010", "68010", "M68010")
-        .Cases("m68020", "68020", "M68020")
-        .Cases("m68030", "68030", "M68030")
-        .Cases("m68040", "68040", "M68040")
-        .Cases("m68060", "68060", "M68060")
+        .Cases({"m68000", "68000"}, "M68000")
+        .Cases({"m68010", "68010"}, "M68010")
+        .Cases({"m68020", "68020"}, "M68020")
+        .Cases({"m68030", "68030"}, "M68030")
+        .Cases({"m68040", "68040"}, "M68040")
+        .Cases({"m68060", "68060"}, "M68060")
         .Default(CPUName.str());
   }
   // FIXME: Throw error when multiple sub-architecture flag exist
diff --git a/clang/lib/Driver/ToolChains/Arch/Mips.cpp b/clang/lib/Driver/ToolChains/Arch/Mips.cpp
index 6a6a4ee..8d7b85d 100644
--- a/clang/lib/Driver/ToolChains/Arch/Mips.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/Mips.cpp
@@ -117,7 +117,7 @@ void mips::getMipsCPUAndABI(const ArgList &Args, const llvm::Triple &Triple,
     // Deduce CPU name from ABI name.
     CPUName = llvm::StringSwitch<const char *>(ABIName)
                   .Case("o32", DefMips32CPU)
-                  .Cases("n32", "n64", DefMips64CPU)
+                  .Cases({"n32", "n64"}, DefMips64CPU)
                   .Default("");
   }
 
@@ -467,7 +467,7 @@ bool mips::isNaN2008(const Driver &D, const ArgList &Args,
 
   // NaN2008 is the default for MIPS32r6/MIPS64r6.
   return llvm::StringSwitch<bool>(getCPUName(D, Args, Triple))
-      .Cases("mips32r6", "mips64r6", true)
+      .Cases({"mips32r6", "mips64r6"}, true)
       .Default(false);
 }
 
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index d3ab6f1..30d3e52 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -7879,10 +7879,13 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                        !TC.getTriple().isAndroid() && TC.useIntegratedAs()))
     CmdArgs.push_back("-faddrsig");
 
-  if ((Triple.isOSBinFormatELF() || Triple.isOSBinFormatMachO()) &&
+  const bool HasDefaultDwarf2CFIASM =
+      (Triple.isOSBinFormatELF() || Triple.isOSBinFormatMachO()) &&
       (EH || UnwindTables || AsyncUnwindTables ||
-       DebugInfoKind != llvm::codegenoptions::NoDebugInfo))
-    CmdArgs.push_back("-D__GCC_HAVE_DWARF2_CFI_ASM=1");
+       DebugInfoKind != llvm::codegenoptions::NoDebugInfo);
+  if (Args.hasFlag(options::OPT_fdwarf2_cfi_asm,
+                   options::OPT_fno_dwarf2_cfi_asm, HasDefaultDwarf2CFIASM))
+    CmdArgs.push_back("-fdwarf2-cfi-asm");
 
   if (Arg *A = Args.getLastArg(options::OPT_fsymbol_partition_EQ)) {
     std::string Str = A->getAsString(Args);
diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
index cc5bcd1..2fb7652 100644
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -1035,12 +1035,12 @@ static const char *ArmMachOArchName(StringRef Arch) {
       .Case("xscale", "xscale")
       .Case("armv4t", "armv4t")
       .Case("armv7", "armv7")
-      .Cases("armv7a", "armv7-a", "armv7")
-      .Cases("armv7r", "armv7-r", "armv7")
-      .Cases("armv7em", "armv7e-m", "armv7em")
-      .Cases("armv7k", "armv7-k", "armv7k")
-      .Cases("armv7m", "armv7-m", "armv7m")
-      .Cases("armv7s", "armv7-s", "armv7s")
+      .Cases({"armv7a", "armv7-a"}, "armv7")
+      .Cases({"armv7r", "armv7-r"}, "armv7")
+      .Cases({"armv7em", "armv7e-m"}, "armv7em")
+      .Cases({"armv7k", "armv7-k"}, "armv7k")
+      .Cases({"armv7m", "armv7-m"}, "armv7m")
+      .Cases({"armv7s", "armv7-s"}, "armv7s")
       .Default(nullptr);
 }
 
diff --git a/clang/lib/Driver/ToolChains/Solaris.cpp b/clang/lib/Driver/ToolChains/Solaris.cpp
index 02aa598..64c7d1c 100644
--- a/clang/lib/Driver/ToolChains/Solaris.cpp
+++ b/clang/lib/Driver/ToolChains/Solaris.cpp
@@ -346,7 +346,7 @@ SanitizerMask Solaris::getSupportedSanitizers() const {
 const char *Solaris::getDefaultLinker() const {
   // FIXME: Only handle Solaris ld and GNU ld here.
   return llvm::StringSwitch<const char *>(getDriver().getPreferredLinker())
-      .Cases("bfd", "gld", "/usr/gnu/bin/ld")
+      .Cases({"bfd", "gld"}, "/usr/gnu/bin/ld")
       .Default("/usr/bin/ld");
 }