[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

1 files changed, 16 insertions, 0 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 058fdf5..1795ccf 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");
     }