[MIPS] Add support for direct-to-nacl in Clang

[petarj]

Summary

[MIPS] Add support for direct-to-nacl in Clang

For Mips direct-to-nacl, the goal is to be close to le32 front-end and
use Mips32EL backend. This patch defines new NaClMips32ELTargetInfo and
modifies it slightly to be close to le32. It also adds necessary parts,
inline with ARM and X86.

[dschuff]

lib/Driver/ToolChains.cpp

2321

should this be mipsel-nacl/bin?

2368

it seems wrong to include a C++ path here; I don't think this function is C++ specific?
And in any case, is this intended to override -nobuiltininc?

lib/Driver/Tools.cpp

1177

this part may not be upstreamable since the LLVM part that implements it won't be upstreamable.

8268

which symbols are causing trouble here, and how? can you give some more detail?

I wasn't aware of the difference, but I have an unrelated change that may be affected by it.

[petarj]

lib/Driver/ToolChains.cpp

2321

should this be mipsel-nacl/bin?

Not in our version today. "bin" is required/sufficient to find mipsel-nacl-ld.
This way we do not need to install ld into a new location.

2368

ooouch, this hunk ended up in the wrong function.

lib/Driver/Tools.cpp

1177

OK, I will remove it in the next patch set.

8268

which symbols are causing trouble here,

Symbols that are same in both libraries. One example is picking wrong implementation of __libnacl_irt_thread.

and how? can you give some more detail?

Take a look at example that Nikola reported at

https://sourceware.org/ml/binutils/2015-03/msg00017.html

[petarj]

New patch uploaded. PTAL.

[petarj]

Ping.

[dschuff]

lib/Driver/ToolChains.cpp

2321

this is ok for now. at some point I want to rework how the nacl file-path code works because it's a bit nonstandard... I'd like for e.g. --sysroot to work (it doesn't today).

[dschuff]

oh, also don't forget to add a test, similar to nacl-direct.c (or add to that directly)

[petarj]

Patch rebased and test added to test/Driver/nacl-direct.c.

lib/Basic/Targets.cpp

 }
 
 void PNaClTargetInfo::getGCCRegAliases(const GCCRegAlias *&Aliases,
                                        unsigned &NumAliases) const {
   Aliases = nullptr;
   NumAliases = 0;
 }
 
+// We attempt to use PNaCl (le32) frontend and Mips32EL backend.
+class NaClMips32ELTargetInfo : public Mips32ELTargetInfo {
+public:
+  NaClMips32ELTargetInfo(const llvm::Triple &Triple) :
+    Mips32ELTargetInfo(Triple)  {
+      MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
+  }
+
+  BuiltinVaListKind getBuiltinVaListKind() const override {
+    return TargetInfo::PNaClABIBuiltinVaList;
+  }
+};
+
 class Le64TargetInfo : public TargetInfo {
   static const Builtin::Info BuiltinInfo[];
 
 public:
   Le64TargetInfo(const llvm::Triple &Triple) : TargetInfo(Triple) {
     BigEndian = false;
     NoAsmVariants = true;
     LongWidth = LongAlign = PointerWidth = PointerAlign = 64;
case llvm::Triple::Linux:
       return new LinuxTargetInfo<Mips32ELTargetInfo>(Triple);
     case llvm::Triple::RTEMS:
       return new RTEMSTargetInfo<Mips32ELTargetInfo>(Triple);
     case llvm::Triple::FreeBSD:
       return new FreeBSDTargetInfo<Mips32ELTargetInfo>(Triple);
     case llvm::Triple::NetBSD:
       return new NetBSDTargetInfo<Mips32ELTargetInfo>(Triple);
     case llvm::Triple::NaCl:
-      return new NaClTargetInfo<Mips32ELTargetInfo>(Triple);
+      return new NaClTargetInfo<NaClMips32ELTargetInfo>(Triple);
     default:
       return new Mips32ELTargetInfo(Triple);
     }
 
   case llvm::Triple::mips64:
     switch (os) {
     case llvm::Triple::Linux:
       return new LinuxTargetInfo<Mips64EBTargetInfo>(Triple);

lib/CodeGen/TargetInfo.cpp

const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
   switch (Triple.getArch()) {
   default:
     return *(TheTargetCodeGenInfo = new DefaultTargetCodeGenInfo(Types));
 
   case llvm::Triple::le32:
     return *(TheTargetCodeGenInfo = new PNaClTargetCodeGenInfo(Types));
   case llvm::Triple::mips:
   case llvm::Triple::mipsel:
+    if (Triple.getOS() == llvm::Triple::NaCl)
+      return *(TheTargetCodeGenInfo = new PNaClTargetCodeGenInfo(Types));
     return *(TheTargetCodeGenInfo = new MIPSTargetCodeGenInfo(Types, true));
 
   case llvm::Triple::mips64:
   case llvm::Triple::mips64el:
     return *(TheTargetCodeGenInfo = new MIPSTargetCodeGenInfo(Types, false));
 
   case llvm::Triple::aarch64:
   case llvm::Triple::aarch64_be: {

lib/Driver/ToolChains.h

void AddClangCXXStdlibIncludeArgs(
       const llvm::opt::ArgList &DriverArgs,
       llvm::opt::ArgStringList &CC1Args) const override;
 
   CXXStdlibType GetCXXStdlibType(const llvm::opt::ArgList &Args) const override;
 
   void AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
                            llvm::opt::ArgStringList &CmdArgs) const override;
 
-  bool IsIntegratedAssemblerDefault() const override { return false; }
+  bool IsIntegratedAssemblerDefault() const override {
+    return getTriple().getArch() == llvm::Triple::mipsel;
+  }
 
   // Get the path to the file containing NaCl's ARM macros. It lives in NaCl_TC
   // because the AssembleARM tool needs a const char * that it can pass around
   // and the toolchain outlives all the jobs.
   const char *GetNaClArmMacrosPath() const { return NaClArmMacrosPath.c_str(); }
 
   std::string ComputeEffectiveClangTriple(const llvm::opt::ArgList &Args,
                                           types::ID InputType) const override;

lib/Driver/ToolChains.cpp

NaCl_TC::NaCl_TC(const Driver &D, const llvm::Triple &Triple,
   std::string ProgPath(getDriver().Dir + "/../");
 
   // Path for toolchain libraries (libgcc.a, ...)
   std::string ToolPath(getDriver().ResourceDir + "/lib/");
 
   switch (Triple.getArch()) {
   case llvm::Triple::x86: {
     file_paths.push_back(FilePath + "x86_64-nacl/lib32");
     file_paths.push_back(FilePath + "x86_64-nacl/usr/lib32");
     prog_paths.push_back(ProgPath + "x86_64-nacl/bin");
     file_paths.push_back(ToolPath + "i686-nacl");
     break;
   }
   case llvm::Triple::x86_64: {
     file_paths.push_back(FilePath + "x86_64-nacl/lib");
     file_paths.push_back(FilePath + "x86_64-nacl/usr/lib");
     prog_paths.push_back(ProgPath + "x86_64-nacl/bin");
     file_paths.push_back(ToolPath + "x86_64-nacl");
     break;
   }
   case llvm::Triple::arm: {
     file_paths.push_back(FilePath + "arm-nacl/lib");
     file_paths.push_back(FilePath + "arm-nacl/usr/lib");
     prog_paths.push_back(ProgPath + "arm-nacl/bin");
     file_paths.push_back(ToolPath + "arm-nacl");
     break;
   }
+  case llvm::Triple::mipsel: {
+    file_paths.push_back(FilePath + "mipsel-nacl/lib");
+    file_paths.push_back(FilePath + "mipsel-nacl/usr/lib");
+    prog_paths.push_back(ProgPath + "bin");
+    file_paths.push_back(ToolPath + "mipsel-nacl");
+    break;
+  }
   default:
     break;
   }
 
   // Use provided linker, not system linker
   Linker = GetProgramPath("ld");
   NaClArmMacrosPath = GetFilePath("nacl-arm-macros.s");
 }
 
 void NaCl_TC::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
                                         ArgStringList &CC1Args) const {
   const Driver &D = getDriver();
   if (DriverArgs.hasArg(options::OPT_nostdinc))
     return;
 
   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
     SmallString<128> P(D.ResourceDir);
     llvm::sys::path::append(P, "include");
     addSystemInclude(DriverArgs, CC1Args, P.str());
   }
 
   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
     return;
 
   SmallString<128> P(D.Dir + "/../");
   switch (getTriple().getArch()) {
   case llvm::Triple::arm:
     llvm::sys::path::append(P, "arm-nacl/usr/include");
     break;
   case llvm::Triple::x86:
     llvm::sys::path::append(P, "x86_64-nacl/usr/include");
     break;
   case llvm::Triple::x86_64:
     llvm::sys::path::append(P, "x86_64-nacl/usr/include");
     break;
+  case llvm::Triple::mipsel:
+    llvm::sys::path::append(P, "mipsel-nacl/usr/include");
+    break;
   default:
     return;
   }
 
   addSystemInclude(DriverArgs, CC1Args, P.str());
   llvm::sys::path::remove_filename(P);
   llvm::sys::path::remove_filename(P);
   llvm::sys::path::append(P, "include");
void NaCl_TC::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
   case llvm::Triple::x86:
     llvm::sys::path::append(P, "x86_64-nacl/include/c++/v1");
     addSystemInclude(DriverArgs, CC1Args, P.str());
     break;
   case llvm::Triple::x86_64:
     llvm::sys::path::append(P, "x86_64-nacl/include/c++/v1");
     addSystemInclude(DriverArgs, CC1Args, P.str());
     break;
+  case llvm::Triple::mipsel:
+    llvm::sys::path::append(P, "mipsel-nacl/include/c++/v1");
+    addSystemInclude(DriverArgs, CC1Args, P.str());
+    break;
   default:
     break;
   }
 }
 
 ToolChain::CXXStdlibType NaCl_TC::GetCXXStdlibType(const ArgList &Args) const {
   if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
     StringRef Value = A->getValue();

lib/Driver/Tools.cpp

void Clang::AddMIPSTargetArgs(const ArgList &Args,
 
   if (Arg *A = Args.getLastArg(options::OPT_G)) {
     StringRef v = A->getValue();
     CmdArgs.push_back("-mllvm");
     CmdArgs.push_back(Args.MakeArgString("-mips-ssection-threshold=" + v));
     A->claim();
   }
 }
 
 /// getPPCTargetCPU - Get the (LLVM) name of the PowerPC cpu we are targeting.
 static std::string getPPCTargetCPU(const ArgList &Args) {
   if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
     StringRef CPUName = A->getValue();
 
     if (CPUName == "native") {
       std::string CPU = llvm::sys::getHostCPUName();
       if (!CPU.empty() && CPU != "generic")
void nacltools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   CmdArgs.push_back("-m");
   if (Arch == llvm::Triple::x86)
     CmdArgs.push_back("elf_i386_nacl");
   else if (Arch == llvm::Triple::arm)
     CmdArgs.push_back("armelf_nacl");
   else if (Arch == llvm::Triple::x86_64)
     CmdArgs.push_back("elf_x86_64_nacl");
+  else if (Arch == llvm::Triple::mipsel)
+    CmdArgs.push_back("mipselelf_nacl");
   else
     D.Diag(diag::err_target_unsupported_arch) << ToolChain.getArchName()
                                               << "Native Client";
 
   if (IsStatic)
     CmdArgs.push_back("-static");
   else if (Args.hasArg(options::OPT_shared))
     CmdArgs.push_back("-shared");
if (!Args.hasArg(options::OPT_nostdlib)) {
     if (!Args.hasArg(options::OPT_nodefaultlibs)) {
       // Always use groups, since it has no effect on dynamic libraries.
       CmdArgs.push_back("--start-group");
       CmdArgs.push_back("-lc");
       // NaCl's libc++ currently requires libpthread, so just always include it
       // in the group for C++.
       if (Args.hasArg(options::OPT_pthread) ||
           Args.hasArg(options::OPT_pthreads) || D.CCCIsCXX()) {
+        // Gold, used by Mips, handles nested groups differently than ld, and
+        // without '-lnacl' it prefers symbols from libpthread.a over libnacl.a,
+        // which is not a desired behaviour here.
+        // See https://sourceware.org/ml/binutils/2015-03/msg00034.html
+        if (getToolChain().getArch() == llvm::Triple::mipsel)
+          CmdArgs.push_back("-lnacl");
+
         CmdArgs.push_back("-lpthread");
       }
 
       CmdArgs.push_back("-lgcc");
       CmdArgs.push_back("--as-needed");
       if (IsStatic)
         CmdArgs.push_back("-lgcc_eh");
       else
         CmdArgs.push_back("-lgcc_s");
       CmdArgs.push_back("--no-as-needed");
+
+      // Mips needs to create and use pnacl_legacy library that contains
+      // definitions from bitcode/pnaclmm.c and definitions for
+      // __nacl_tp_tls_offset() and __nacl_tp_tdb_offset().
+      if (getToolChain().getArch() == llvm::Triple::mipsel)
+        CmdArgs.push_back("-lpnacl_legacy");
+
       CmdArgs.push_back("--end-group");
     }
 
     if (!Args.hasArg(options::OPT_nostartfiles)) {
       const char *crtend;
       if (Args.hasArg(options::OPT_shared))
         crtend = "crtendS.o";
       else

test/Driver/nacl-direct.c

 // CHECK-ARM: ld{{(.exe)?}}"
 // CHECK-ARM: "--build-id"
 // CHECK-ARM: "-m" "armelf_nacl"
 // CHECK-ARM: "-static"
 // CHECK-ARM: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}arm-nacl{{/|\\\\}}lib"
 // CHECK-ARM: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}arm-nacl{{/|\\\\}}usr{{/|\\\\}}lib"
 // CHECK-ARM: "-Lfoo{{/|\\\\}}lib{{/|\\\\}}arm-nacl"
 // CHECK-ARM-NOT: -lpthread
+//
+// RUN: %clang -no-canonical-prefixes -### -o %t.o %s \
+// RUN:     -target mipsel-unknown-nacl -resource-dir foo 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MIPS %s
+// CHECK-MIPS: {{.*}}clang{{.*}}" "-cc1"
+// CHECK-MIPS: "-fuse-init-array"
+// CHECK-MIPS: "-target-cpu" "mips32r2"
+// CHECK-MIPS: "-target-abi" "o32"
+// CHECK-MIPS: "-mfloat-abi" "hard"
+// CHECK-MIPS: "-resource-dir" "foo"
+// CHECK-MIPS: "-internal-isystem" "foo{{/|\\\\}}include"
+// CHECK-MIPS: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}mipsel-nacl{{/|\\\\}}usr{{/|\\\\}}include"
+// CHECK-MIPS: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}mipsel-nacl{{/|\\\\}}include"
+// CHECK-MIPS-NOT: as{{(.exe)?}}"
+// CHECK-MIPS: ld{{(.exe)?}}"
+// CHECK-MIPS: "--build-id"
+// CHECK-MIPS: "-m" "mipselelf_nacl"
+// CHECK-MIPS: "-static"
+// CHECK-MIPS: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}mipsel-nacl{{/|\\\\}}lib"
+// CHECK-MIPS: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}mipsel-nacl{{/|\\\\}}usr{{/|\\\\}}lib"
+// CHECK-MIPS: "-Lfoo{{/|\\\\}}lib{{/|\\\\}}mipsel-nacl"
+// CHECK-MIPS: "-lpnacl_legacy"
+// CHECK-MIPS-NOT: "-lpthread"
 
 // Check that even when the target arch is just "arm" (as will be the case when
 // it is inferred from the binary name) that we get the right ABI flags
 // RUN: %clang -no-canonical-prefixes -### -o %t.o %s 2>&1 \
 // RUN:     -target arm-nacl \
 // RUN:   | FileCheck --check-prefix=CHECK-ARM-NOV7 %s
 // CHECK-ARM-NOV7: "-triple" "armv7--nacl-gnueabihf"
 // CHECK-ARM-NOV7: "-target-abi" "aapcs-linux"

 // RUN:   | FileCheck --check-prefix=CHECK-x86_64-CXX %s
 // CHECK-x86_64-CXX: {{.*}}clang{{.*}}" "-cc1"
 // CHECK-x86_64-CXX: "-resource-dir" "foo"
 // CHECK-x86_64-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}v1"
 // CHECK-x86_64-CXX: "-internal-isystem" "foo{{/|\\\\}}include"
 // CHECK-x86_64-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}usr{{/|\\\\}}include"
 // CHECK-x86_64-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}include"
 // CHECK-x86_64-CXX: "-lpthread"
+
+// RUN: %clangxx -no-canonical-prefixes -### -o %t.o %s \
+// RUN:     -target mipsel-unknown-nacl -resource-dir foo 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MIPS-CXX %s
+// CHECK-MIPS-CXX: {{.*}}clang{{.*}}" "-cc1"
+// CHECK-MIPS-CXX: "-resource-dir" "foo"
+// CHECK-MIPS-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}mipsel-nacl{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}v1"
+// CHECK-MIPS-CXX: "-internal-isystem" "foo{{/|\\\\}}include"
+// CHECK-MIPS-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}mipsel-nacl{{/|\\\\}}usr{{/|\\\\}}include"
+// CHECK-MIPS-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}mipsel-nacl{{/|\\\\}}include"
+// CHECK-MIPS-CXX: "-lnacl"
+// CHECK-MIPS-CXX: "-lpthread"