[Driver][M68k] (Patch 8/8) Add driver support for M68k

[myhsu]

Summary

Add new toolchain and driver options for the M68k target

[myhsu]

Fix formatting issues

[myhsu]

• Use the canonical CPU name (i.e. names started with upper case 'M')
• Tell the driver to use integrated assembler (i.e. MC) by default

[myhsu]

[NFC] Rename M680x0 to M68k

[RKSimon]

Some very minor nits - the 68060 omission is the biggest one (apple might not have used it but commodore did!)

clang/include/clang/Driver/Options.td

168

(sorting) put this before mips?

clang/lib/Driver/ToolChains/Arch/M68k.cpp

45

Why no 68060 ?

65

(style) remove unnecessary braces?

73

(clang-format) indentation?

95

remove braces

clang/lib/Driver/ToolChains/Arch/M68k.h

36

(clang-format) indentation?

39

(clang-tidy) end namespace tools

clang/lib/Driver/ToolChains/Clang.cpp

383

(sorting) move before msp430 ?

clang/lib/Driver/ToolChains/CommonArgs.cpp

371

(sorting) move down to before mips ?

[rengolin]

clang/include/clang/Driver/Options.td

3234

Same question as @RKSimon had below: Shouldn't this cover all models the back-end recognises?

clang/lib/Driver/ToolChains/Gnu.cpp

2103

The front-end supports FreeBSD, too.

[RKSimon]

clang/lib/Driver/ToolChains/Arch/M68k.cpp

52

Can't we just use StringSwitch here?

[bruno]

clang/include/clang/Driver/Options.td

3234

Unless you are planning to add 100 or more target variations I'd prefer to see these explicitly defined instead of a foreach. If I'm grepping for a specific CPU variation in the code base it's nice to get that information easily.

clang/lib/Driver/ToolChains/Arch/M68k.cpp

38

No need for this else here.

52

+1

65

and also the unnecessary elses.

[myhsu]

• Rebased to latest changes
• Addressed some of the feedbacks

clang/include/clang/Driver/Options.td

3234

@rengolin I think the backend currently doesn't support M68060 either

[myhsu]

• Add support for M68060 sub-target

[myhsu]

clang/include/clang/Driver/Options.td

3234

Update: I've just put the sub-target (skeleton) for M68060. So now you can specific M68060 :-)

clang/lib/Driver/ToolChains/Arch/M68k.cpp

45

@RKSimon Just added 060's support :-)
Currently I don't see any major ISA difference between 060 and 040 (correct me if I'm wrong). So I just put a sub-target skeleton and clang support for 060, and fill in the details in the future

[bruno]

clang/include/clang/Driver/Options.td

164

Looks like this is missing clang-format?

[craig.topper]

clang/include/clang/Driver/Options.td

164

I don't think clang-format really understands tablegen files.

[rengolin]

clang/include/clang/Driver/Options.td

164

It does not. Don't clang-format table-gen files, the end result is horrendous. :)

[myhsu]

• [NFC] Fix minor formatting

[bruno]

LGTM, it would be great if someone else stamps this too, in case I missed something.

clang/include/clang/Driver/Options.td

164

Thanks for pointing out, thinko for "please format"

[rengolin]

LGTM too, thanks!

[MaskRay]

clang/lib/Driver/ToolChains/Arch/M68k.h

39

mismatching end and no end?

clang-format seems to drop end. I think that style can be picked if convenient.

clang/lib/Driver/ToolChains/Gnu.cpp

2101

The second const is redundant

[jrtc27]

clang/lib/Driver/ToolChains/Gnu.cpp

2103

Aren't these arrays only used on multiarch systems so irrelevant for BSDs? There aren't FreeBSD triples listed for X86/X86_64 for example.

[rengolin]

clang/lib/Driver/ToolChains/Gnu.cpp

2103

Makes sense.

[myhsu]

• Addressed feedbacks

[myhsu]

clang/lib/Driver/ToolChains/Gnu.cpp

2101

I don't think so...first, const char *const means "a pointer points to const char, and you can't modify this pointer", which make sense in this context. Second, all the surrounding code here are using const char *const.

[jrtc27]

clang/lib/Driver/ToolChains/Clang.cpp

380

Unrelated

clang/test/Driver/m68k-sub-archs.cpp

2

Why MX00 etc?

[jrtc27]

clang/lib/Driver/ToolChains/Clang.cpp

380

I committed this as 22215e492338, should disappear if you rebase (or you can just drop the diff if you don't plan to rebase)

[myhsu]

• Addressed feedbacks

[myhsu]

clang/lib/Driver/ToolChains/Clang.cpp

380

thanks, I'll drop the change for this line

[jrtc27]

clang/test/Driver/m68k-sub-archs.cpp

2

I think you misunderstood my comment. Having CHECK-A, CHECK-B, CHECK-C etc is fine. My issue was with the MX00/MX10/MX20 suffix that makes no sense to me; it's M68000/M68010/etc, X normally stands for a variable, but the 0 is always constant. M00/M10/etc, M000/M010/etc and M68000/M68010/M68020 would seem like more sensible names (also without the M would be fine), but MX00 looks like it's trying to match M000/M100/M200/etc, which is not the case.

[glaubitz]

clang/test/Driver/m68k-sub-archs.cpp

2

From what I can see, I would say it's supposed to represent the "680" in "M68020", for example.

[jrtc27]

clang/test/Driver/m68k-sub-archs.cpp

2

Yeah, I just don't think it's particularly intuitive, especially when the backend was originally intended to be called M680x0, the use of an X to stand in for different things in very similar situations is confusing.

[glaubitz]

clang/test/Driver/m68k-sub-archs.cpp

2

You're right, it's not very intuitive but I think it's not that important in my opinion.

[myhsu]

[NFC] Update FileCheck prefix

clang/include/clang/Driver/Options.td

 def m_arm_Features_Group : OptionGroup<"<arm features group>">,
                            Group<m_Group>, DocName<"ARM">;
 def m_hexagon_Features_Group : OptionGroup<"<hexagon features group>">,
                                Group<m_Group>, DocName<"Hexagon">;
 // The features added by this group will not be added to target features.
 // These are explicitly handled.
 def m_hexagon_Features_HVX_Group : OptionGroup<"<hexagon features group>">,
                                    Group<m_Group>, DocName<"Hexagon">;
+def m_m68k_Features_Group: OptionGroup<"<m68k features group>">,
+                           Group<m_Group>, DocName<"M68k">;
 def m_mips_Features_Group : OptionGroup<"<mips features group>">,
                             Group<m_Group>, DocName<"MIPS">;
 def m_ppc_Features_Group : OptionGroup<"<ppc features group>">,
                            Group<m_Group>, DocName<"PowerPC">;
 def m_wasm_Features_Group : OptionGroup<"<wasm features group>">,
                             Group<m_Group>, DocName<"WebAssembly">;
 // The features added by this group will not be added to target features.
 // These are explicitly handled.
 def m_wasm_Features_Driver_Group : OptionGroup<"<wasm driver features group>">,
                                    Group<m_Group>, DocName<"WebAssembly Driver">;
 def m_x86_Features_Group : OptionGroup<"<x86 features group>">,
                            Group<m_Group>, Flags<[CoreOption]>, DocName<"X86">;
def mnvj : Flag<["-"], "mnvj">, Group<m_hexagon_Features_Group>,
   Flags<[CC1Option]>, HelpText<"Enable generation of new-value jumps">;
 def mno_nvj : Flag<["-"], "mno-nvj">, Group<m_hexagon_Features_Group>,
   Flags<[CC1Option]>, HelpText<"Disable generation of new-value jumps">;
 def mnvs : Flag<["-"], "mnvs">, Group<m_hexagon_Features_Group>,
   Flags<[CC1Option]>, HelpText<"Enable generation of new-value stores">;
 def mno_nvs : Flag<["-"], "mno-nvs">, Group<m_hexagon_Features_Group>,
   Flags<[CC1Option]>, HelpText<"Disable generation of new-value stores">;
 
+// M68k features flags
+def m68000 : Flag<["-"], "m68000">, Group<m_m68k_Features_Group>;
+def m68010 : Flag<["-"], "m68010">, Group<m_m68k_Features_Group>;
+def m68020 : Flag<["-"], "m68020">, Group<m_m68k_Features_Group>;
+def m68030 : Flag<["-"], "m68030">, Group<m_m68k_Features_Group>;
+def m68040 : Flag<["-"], "m68040">, Group<m_m68k_Features_Group>;
+def m68060 : Flag<["-"], "m68060">, Group<m_m68k_Features_Group>;
 
 // X86 feature flags
 def mx87 : Flag<["-"], "mx87">, Group<m_x86_Features_Group>;
 def mno_x87 : Flag<["-"], "mno-x87">, Group<m_x86_Features_Group>;
 def m80387 : Flag<["-"], "m80387">, Alias<mx87>;
 def mno_80387 : Flag<["-"], "mno-80387">, Alias<mno_x87>;
 def mmmx : Flag<["-"], "mmmx">, Group<m_x86_Features_Group>;
 def mno_mmx : Flag<["-"], "mno-mmx">, Group<m_x86_Features_Group>;

clang/lib/Driver/CMakeLists.txt

add_clang_library(clangDriver
   Multilib.cpp
   OptionUtils.cpp
   Phases.cpp
   SanitizerArgs.cpp
   Tool.cpp
   ToolChain.cpp
   ToolChains/Arch/AArch64.cpp
   ToolChains/Arch/ARM.cpp
+  ToolChains/Arch/M68k.cpp
   ToolChains/Arch/Mips.cpp
   ToolChains/Arch/PPC.cpp
   ToolChains/Arch/RISCV.cpp
   ToolChains/Arch/Sparc.cpp
   ToolChains/Arch/SystemZ.cpp
   ToolChains/Arch/VE.cpp
   ToolChains/Arch/X86.cpp
   ToolChains/AIX.cpp

clang/lib/Driver/ToolChains/Arch/M68k.h

+//===--- M68k.h - M68k-specific Tool Helpers -----------------*- C++-*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_ARCH_M680X0_H
+#define LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_ARCH_M680X0_H
+
+#include "clang/Driver/Driver.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Option/Option.h"
+#include <string>
+#include <vector>
+
+namespace clang {
+namespace driver {
+namespace tools {
+namespace m68k {
+
+enum class FloatABI {
+  Invalid,
+  Soft,
+  Hard,
+};
+
+FloatABI getM68kFloatABI(const Driver &D, const llvm::opt::ArgList &Args);
+
+std::string getM68kTargetCPU(const llvm::opt::ArgList &Args);
+
+void getM68kTargetFeatures(const Driver &D, const llvm::Triple &Triple,
+                           const llvm::opt::ArgList &Args,
+                           std::vector<llvm::StringRef> &Features);
+
+} // end namespace m68k
+} // end namespace tools
+} // end namespace driver
+} // end namespace clang
+
+#endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_ARCH_M680X0_H

clang/lib/Driver/ToolChains/Arch/M68k.cpp

+//===--- M68k.cpp - M68k Helpers for Tools -------------------*- C++-*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "M68k.h"
+#include "ToolChains/CommonArgs.h"
+#include "clang/Driver/Driver.h"
+#include "clang/Driver/DriverDiagnostic.h"
+#include "clang/Driver/Options.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/Regex.h"
+#include <sstream>
+
+using namespace clang::driver;
+using namespace clang::driver::tools;
+using namespace clang;
+using namespace llvm::opt;
+
+/// getM68kTargetCPU - Get the (LLVM) name of the 68000 cpu we are targeting.
+std::string m68k::getM68kTargetCPU(const ArgList &Args) {
+  if (Arg *A = Args.getLastArg(clang::driver::options::OPT_mcpu_EQ)) {
+    // The canonical CPU name is captalize. However, we allow
+    // starting with lower case or numbers only
+    StringRef CPUName = A->getValue();
+
+    if (CPUName == "native") {
+      std::string CPU = std::string(llvm::sys::getHostCPUName());
+      if (!CPU.empty() && CPU != "generic")
+        return CPU;
+    }
+
+    if (CPUName == "common")
+      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")
+        .Default(CPUName.str());
+  }
+  // FIXME: Throw error when multiple sub-architecture flag exist
+  if (Args.hasArg(clang::driver::options::OPT_m68000))
+    return "M68000";
+  if (Args.hasArg(clang::driver::options::OPT_m68010))
+    return "M68010";
+  if (Args.hasArg(clang::driver::options::OPT_m68020))
+    return "M68020";
+  if (Args.hasArg(clang::driver::options::OPT_m68030))
+    return "M68030";
+  if (Args.hasArg(clang::driver::options::OPT_m68040))
+    return "M68040";
+  if (Args.hasArg(clang::driver::options::OPT_m68060))
+    return "M68060";
+
+  return "";
+}
+
+void m68k::getM68kTargetFeatures(const Driver &D, const llvm::Triple &Triple,
+                                 const ArgList &Args,
+                                 std::vector<StringRef> &Features) {
+
+  m68k::FloatABI FloatABI = m68k::getM68kFloatABI(D, Args);
+  if (FloatABI == m68k::FloatABI::Soft)
+    Features.push_back("-hard-float");
+}
+
+m68k::FloatABI m68k::getM68kFloatABI(const Driver &D, const ArgList &Args) {
+  m68k::FloatABI ABI = m68k::FloatABI::Invalid;
+  if (Arg *A =
+          Args.getLastArg(options::OPT_msoft_float, options::OPT_mhard_float)) {
+
+    if (A->getOption().matches(options::OPT_msoft_float))
+      ABI = m68k::FloatABI::Soft;
+    else if (A->getOption().matches(options::OPT_mhard_float))
+      ABI = m68k::FloatABI::Hard;
+  }
+
+  // If unspecified, choose the default based on the platform.
+  if (ABI == m68k::FloatABI::Invalid)
+    ABI = m68k::FloatABI::Hard;
+
+  return ABI;
+}

clang/lib/Driver/ToolChains/Clang.cpp

 //===-- Clang.cpp - Clang+LLVM ToolChain Implementations --------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "Clang.h"
 #include "AMDGPU.h"
 #include "Arch/AArch64.h"
 #include "Arch/ARM.h"
+#include "Arch/M68k.h"
 #include "Arch/Mips.h"
 #include "Arch/PPC.h"
 #include "Arch/RISCV.h"
 #include "Arch/Sparc.h"
 #include "Arch/SystemZ.h"
 #include "Arch/VE.h"
 #include "Arch/X86.h"
 #include "CommonArgs.h"
static void getTargetFeatures(const Driver &D, const llvm::Triple &Triple,
   case llvm::Triple::sparcel:
   case llvm::Triple::sparcv9:
     sparc::getSparcTargetFeatures(D, Args, Features);
     break;
   case llvm::Triple::r600:
   case llvm::Triple::amdgcn:
     amdgpu::getAMDGPUTargetFeatures(D, Triple, Args, Features);
     break;
+  case llvm::Triple::m68k:
+    m68k::getM68kTargetFeatures(D, Triple, Args, Features);
+    break;
   case llvm::Triple::msp430:
     msp430::getMSP430TargetFeatures(D, Args, Features);
     break;
   case llvm::Triple::ve:
     ve::getVETargetFeatures(D, Args, Features);
   }
 
   for (auto Feature : unifyTargetFeatures(Features)) {
     CmdArgs.push_back(IsAux ? "-aux-target-feature" : "-target-feature");
     CmdArgs.push_back(Feature.data());
   }
 }
 
 static bool
 shouldUseExceptionTablesForObjCExceptions(const ObjCRuntime &runtime,
                                           const llvm::Triple &Triple) {
   // We use the zero-cost exception tables for Objective-C if the non-fragile

clang/lib/Driver/ToolChains/CommonArgs.cpp

 //===--- CommonArgs.cpp - Args handling for multiple toolchains -*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "CommonArgs.h"
 #include "Arch/AArch64.h"
 #include "Arch/ARM.h"
+#include "Arch/M68k.h"
 #include "Arch/Mips.h"
 #include "Arch/PPC.h"
 #include "Arch/SystemZ.h"
 #include "Arch/VE.h"
 #include "Arch/X86.h"
 #include "HIP.h"
 #include "Hexagon.h"
 #include "InputInfo.h"
std::string tools::getCPUName(const ArgList &Args, const llvm::Triple &T,
   case llvm::Triple::thumb:
   case llvm::Triple::thumbeb: {
     StringRef MArch, MCPU;
     arm::getARMArchCPUFromArgs(Args, MArch, MCPU, FromAs);
     return arm::getARMTargetCPU(MCPU, MArch, T);
   }
 
   case llvm::Triple::avr:
     if (const Arg *A = Args.getLastArg(options::OPT_mmcu_EQ))
       return A->getValue();
     return "";
 
+  case llvm::Triple::m68k:
+    return m68k::getM68kTargetCPU(Args);
+
   case llvm::Triple::mips:
   case llvm::Triple::mipsel:
   case llvm::Triple::mips64:
   case llvm::Triple::mips64el: {
     StringRef CPUName;
     StringRef ABIName;
     mips::getMipsCPUAndABI(Args, T, CPUName, ABIName);
     return std::string(CPUName);

clang/lib/Driver/ToolChains/Gnu.cpp

case llvm::Triple::aarch64:
     return "aarch64linux";
   case llvm::Triple::aarch64_be:
     return "aarch64linuxb";
   case llvm::Triple::arm:
   case llvm::Triple::thumb:
   case llvm::Triple::armeb:
   case llvm::Triple::thumbeb:
     return isArmBigEndian(T, Args) ? "armelfb_linux_eabi" : "armelf_linux_eabi";
+  case llvm::Triple::m68k:
+    return "m68kelf";
   case llvm::Triple::ppc:
     return "elf32ppclinux";
   case llvm::Triple::ppc64:
     return "elf64ppc";
   case llvm::Triple::ppc64le:
     return "elf64lppc";
   case llvm::Triple::riscv32:
     return "elf32lriscv";
/*static*/ void Generic_GCC::GCCInstallationDetector::CollectLibDirsAndTriples(
   static const char *const X86Triples[] = {
       "i686-linux-gnu",       "i686-pc-linux-gnu",     "i486-linux-gnu",
       "i386-linux-gnu",       "i386-redhat-linux6E",   "i686-redhat-linux",
       "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"};
 
+  static const char *const M68kLibDirs[] = {"/lib"};
+  static const char *const M68kTriples[] = {
+      "m68k-linux-gnu", "m68k-unknown-linux-gnu", "m68k-suse-linux"};
+
   static const char *const MIPSLibDirs[] = {"/lib"};
   static const char *const MIPSTriples[] = {
       "mips-linux-gnu", "mips-mti-linux", "mips-mti-linux-gnu",
       "mips-img-linux-gnu", "mipsisa32r6-linux-gnu"};
   static const char *const MIPSELLibDirs[] = {"/lib"};
   static const char *const MIPSELTriples[] = {
       "mipsel-linux-gnu", "mips-img-linux-gnu", "mipsisa32r6el-linux-gnu",
       "mipsel-linux-android"};
case llvm::Triple::x86:
     // MCU toolchain is 32 bit only and its triple alias is TargetTriple
     // itself, which will be appended below.
     if (!TargetTriple.isOSIAMCU()) {
       TripleAliases.append(begin(X86Triples), end(X86Triples));
       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
       BiarchTripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
     }
     break;
+  case llvm::Triple::m68k:
+    LibDirs.append(begin(M68kLibDirs), end(M68kLibDirs));
+    TripleAliases.append(begin(M68kTriples), end(M68kTriples));
+    break;
   case llvm::Triple::mips:
     LibDirs.append(begin(MIPSLibDirs), end(MIPSLibDirs));
     TripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
     BiarchLibDirs.append(begin(MIPS64LibDirs), end(MIPS64LibDirs));
     BiarchTripleAliases.append(begin(MIPS64Triples), end(MIPS64Triples));
     BiarchLibDirs.append(begin(MIPSN32LibDirs), end(MIPSN32LibDirs));
     BiarchTripleAliases.append(begin(MIPSN32Triples), end(MIPSN32Triples));
     break;
bool Generic_GCC::IsIntegratedAssemblerDefault() const {
   case llvm::Triple::riscv32:
   case llvm::Triple::riscv64:
   case llvm::Triple::systemz:
   case llvm::Triple::mips:
   case llvm::Triple::mipsel:
   case llvm::Triple::mips64:
   case llvm::Triple::mips64el:
   case llvm::Triple::msp430:
+  case llvm::Triple::m68k:
     return true;
   case llvm::Triple::sparc:
   case llvm::Triple::sparcel:
   case llvm::Triple::sparcv9:
     if (getTriple().isOSFreeBSD() || getTriple().isOSOpenBSD() ||
         getTriple().isOSSolaris())
       return true;
     return false;

clang/lib/Driver/ToolChains/Linux.cpp

if (IsAndroid)
       return "aarch64-linux-android";
     if (D.getVFS().exists(SysRoot + "/lib/aarch64-linux-gnu"))
       return "aarch64-linux-gnu";
     break;
   case llvm::Triple::aarch64_be:
     if (D.getVFS().exists(SysRoot + "/lib/aarch64_be-linux-gnu"))
       return "aarch64_be-linux-gnu";
     break;
+
+  case llvm::Triple::m68k:
+    if (D.getVFS().exists(SysRoot + "/lib/m68k-linux-gnu"))
+      return "m68k-linux-gnu";
+    break;
+
   case llvm::Triple::mips: {
     std::string MT = IsMipsR6 ? "mipsisa32r6-linux-gnu" : "mips-linux-gnu";
     if (D.getVFS().exists(SysRoot + "/lib/" + MT))
       return MT;
     break;
   }
   case llvm::Triple::mipsel: {
     if (IsAndroid)
case llvm::Triple::thumbeb: {
     const bool HF =
         Triple.getEnvironment() == llvm::Triple::GNUEABIHF ||
         tools::arm::getARMFloatABI(*this, Args) == tools::arm::FloatABI::Hard;
 
     LibDir = "lib";
     Loader = HF ? "ld-linux-armhf.so.3" : "ld-linux.so.3";
     break;
   }
+  case llvm::Triple::m68k:
+    LibDir = "lib";
+    Loader = "ld.so.1";
+    break;
   case llvm::Triple::mips:
   case llvm::Triple::mipsel:
   case llvm::Triple::mips64:
   case llvm::Triple::mips64el: {
     bool IsNaN2008 = tools::mips::isNaN2008(Args, Triple);
 
     LibDir = "lib" + tools::mips::getMipsABILibSuffix(Args, Triple);
 
void Linux::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
   const StringRef ARMMultiarchIncludeDirs[] = {
       "/usr/include/arm-linux-gnueabi"};
   const StringRef ARMHFMultiarchIncludeDirs[] = {
       "/usr/include/arm-linux-gnueabihf"};
   const StringRef ARMEBMultiarchIncludeDirs[] = {
       "/usr/include/armeb-linux-gnueabi"};
   const StringRef ARMEBHFMultiarchIncludeDirs[] = {
       "/usr/include/armeb-linux-gnueabihf"};
+  const StringRef M68kMultiarchIncludeDirs[] = {"/usr/include/m68k-linux-gnu"};
   const StringRef MIPSMultiarchIncludeDirs[] = {"/usr/include/mips-linux-gnu"};
   const StringRef MIPSELMultiarchIncludeDirs[] = {
       "/usr/include/mipsel-linux-gnu"};
   const StringRef MIPS64MultiarchIncludeDirs[] = {
       "/usr/include/mips64-linux-gnuabi64"};
   const StringRef MIPS64ELMultiarchIncludeDirs[] = {
       "/usr/include/mips64el-linux-gnuabi64"};
   const StringRef MIPSN32MultiarchIncludeDirs[] = {
case llvm::Triple::thumb:
     break;
   case llvm::Triple::armeb:
   case llvm::Triple::thumbeb:
     if (getTriple().getEnvironment() == llvm::Triple::GNUEABIHF)
       MultiarchIncludeDirs = ARMEBHFMultiarchIncludeDirs;
     else
       MultiarchIncludeDirs = ARMEBMultiarchIncludeDirs;
     break;
+  case llvm::Triple::m68k:
+    MultiarchIncludeDirs = M68kMultiarchIncludeDirs;
+    break;
   case llvm::Triple::mips:
     if (getTriple().getSubArch() == llvm::Triple::MipsSubArch_r6)
       MultiarchIncludeDirs = MIPSR6MultiarchIncludeDirs;
     else
       MultiarchIncludeDirs = MIPSMultiarchIncludeDirs;
     break;
   case llvm::Triple::mipsel:
     if (getTriple().getSubArch() == llvm::Triple::MipsSubArch_r6)

clang/test/Driver/m68k-features.cpp

+// Check macro definitions
+// RUN: %clang -target m68k-unknown-linux -m68000 -dM -E %s | FileCheck --check-prefix=CHECK-MX %s
+// CHECK-MX: #define __mc68000 1
+// CHECK-MX: #define __mc68000__ 1
+// CHECK-MX: #define mc68000 1
+
+// RUN: %clang -target m68k-unknown-linux -m68010 -dM -E %s | FileCheck --check-prefix=CHECK-MX10 %s
+// CHECK-MX10: #define __mc68000 1
+// CHECK-MX10: #define __mc68000__ 1
+// CHECK-MX10: #define __mc68010 1
+// CHECK-MX10: #define __mc68010__ 1
+// CHECK-MX10: #define mc68000 1
+// CHECK-MX10: #define mc68010 1
+
+// RUN: %clang -target m68k-unknown-linux -m68020 -dM -E %s | FileCheck --check-prefix=CHECK-MX20 %s
+// CHECK-MX20: #define __mc68000 1
+// CHECK-MX20: #define __mc68000__ 1
+// CHECK-MX20: #define __mc68020 1
+// CHECK-MX20: #define __mc68020__ 1
+// CHECK-MX20: #define mc68000 1
+// CHECK-MX20: #define mc68020 1
+
+// RUN: %clang -target m68k-unknown-linux -m68030 -dM -E %s | FileCheck --check-prefix=CHECK-MX30 %s
+// CHECK-MX30: #define __mc68000 1
+// CHECK-MX30: #define __mc68000__ 1
+// CHECK-MX30: #define __mc68030 1
+// CHECK-MX30: #define __mc68030__ 1
+// CHECK-MX30: #define mc68000 1
+// CHECK-MX30: #define mc68030 1
+
+// RUN: %clang -target m68k-unknown-linux -m68040 -dM -E %s | FileCheck --check-prefix=CHECK-MX40 %s
+// CHECK-MX40: #define __mc68000 1
+// CHECK-MX40: #define __mc68000__ 1
+// CHECK-MX40: #define __mc68040 1
+// CHECK-MX40: #define __mc68040__ 1
+// CHECK-MX40: #define mc68000 1
+// CHECK-MX40: #define mc68040 1
+
+// RUN: %clang -target m68k-unknown-linux -m68060 -dM -E %s | FileCheck --check-prefix=CHECK-MX60 %s
+// CHECK-MX60: #define __mc68000 1
+// CHECK-MX60: #define __mc68000__ 1
+// CHECK-MX60: #define __mc68060 1
+// CHECK-MX60: #define __mc68060__ 1
+// CHECK-MX60: #define mc68000 1
+// CHECK-MX60: #define mc68060 1

clang/test/Driver/m68k-sub-archs.cpp

+// RUN: %clang -### -target m68k-unknown-linux -mcpu=68000 %s 2>&1 | FileCheck --check-prefix=CHECK-M00 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=m68000 %s 2>&1 | FileCheck --check-prefix=CHECK-M00 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=M68000 %s 2>&1 | FileCheck --check-prefix=CHECK-M00 %s
+// RUN: %clang -### -target m68k-unknown-linux -m68000 %s 2>&1 | FileCheck --check-prefix=CHECK-M00 %s
+// CHECK-M00: "-target-cpu" "M68000"
+
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=68010 %s 2>&1 | FileCheck --check-prefix=CHECK-M10 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=m68010 %s 2>&1 | FileCheck --check-prefix=CHECK-M10 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=M68010 %s 2>&1 | FileCheck --check-prefix=CHECK-M10 %s
+// RUN: %clang -### -target m68k-unknown-linux -m68010 %s 2>&1 | FileCheck --check-prefix=CHECK-M10 %s
+// CHECK-M10: "-target-cpu" "M68010"
+
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=68020 %s 2>&1 | FileCheck --check-prefix=CHECK-M20 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=m68020 %s 2>&1 | FileCheck --check-prefix=CHECK-M20 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=M68020 %s 2>&1 | FileCheck --check-prefix=CHECK-M20 %s
+// RUN: %clang -### -target m68k-unknown-linux -m68020 %s 2>&1 | FileCheck --check-prefix=CHECK-M20 %s
+// CHECK-M20: "-target-cpu" "M68020"
+
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=68030 %s 2>&1 | FileCheck --check-prefix=CHECK-M30 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=m68030 %s 2>&1 | FileCheck --check-prefix=CHECK-M30 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=M68030 %s 2>&1 | FileCheck --check-prefix=CHECK-M30 %s
+// RUN: %clang -### -target m68k-unknown-linux -m68030 %s 2>&1 | FileCheck --check-prefix=CHECK-M30 %s
+// CHECK-M30: "-target-cpu" "M68030"
+
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=68040 %s 2>&1 | FileCheck --check-prefix=CHECK-M40 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=m68040 %s 2>&1 | FileCheck --check-prefix=CHECK-M40 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=M68040 %s 2>&1 | FileCheck --check-prefix=CHECK-M40 %s
+// RUN: %clang -### -target m68k-unknown-linux -m68040 %s 2>&1 | FileCheck --check-prefix=CHECK-M40 %s
+// CHECK-M40: "-target-cpu" "M68040"
+
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=68060 %s 2>&1 | FileCheck --check-prefix=CHECK-M60 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=m68060 %s 2>&1 | FileCheck --check-prefix=CHECK-M60 %s
+// RUN: %clang -### -target m68k-unknown-linux -mcpu=M68060 %s 2>&1 | FileCheck --check-prefix=CHECK-M60 %s
+// RUN: %clang -### -target m68k-unknown-linux -m68060 %s 2>&1 | FileCheck --check-prefix=CHECK-M60 %s
+// CHECK-M60: "-target-cpu" "M68060"