[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.

Differential Revision: http://reviews.llvm.org/D10739

llvm-svn: 241678

5 files changed, 49 insertions, 2 deletions

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index db0036721d2..f3f9e38c22f 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -6672,6 +6672,19 @@ void PNaClTargetInfo::getGCCRegAliases(const GCCRegAlias *&Aliases,
   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[];
 
@@ -7042,7 +7055,7 @@ static TargetInfo *AllocateTarget(const llvm::Triple &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);
     }
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 300d3c909f7..6226d213b62 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -7099,6 +7099,8 @@ const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
     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:
diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index df74b41b022..463503ba195 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -2337,6 +2337,13 @@ NaCl_TC::NaCl_TC(const Driver &D, const llvm::Triple &Triple,
     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;
   }
@@ -2372,6 +2379,9 @@ void NaCl_TC::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
   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;
   }
@@ -2416,6 +2426,10 @@ void NaCl_TC::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
     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;
   }
diff --git a/clang/lib/Driver/ToolChains.h b/clang/lib/Driver/ToolChains.h
index 05066ee5f7f..36896820447 100644
--- a/clang/lib/Driver/ToolChains.h
+++ b/clang/lib/Driver/ToolChains.h
@@ -747,7 +747,9 @@ public:
   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
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 058fdf574da..1795ccfca19 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -8200,6 +8200,8 @@ void nacltools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     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";
@@ -8261,6 +8263,13 @@ void nacltools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
       // 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");
       }
 
@@ -8271,6 +8280,13 @@ void nacltools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
       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");
     }