[PATCH] Add EXPERIMENTAL --rtlib=compiler-rt to GNU Clang

[Renato Golin]

Hi eugenis, samsonov, ddunbar,

This commit is not strictly correct nor accounts for all uses (shared
objects, for example), but it allows one to test the compiler-rt library
on GNU targets.
    
Using this patch to run the test-suite has already shown me problems
on ARM. Since this is a Darwin-only flag, nobody is using it, so it
shouldn't be a problem.
    
I will need extension to deal with the shared cases, but since we're
not compiling libclang_rt.so, that's not yet applicable. Many other
problems will have to be fixed first in compiler-rt (such as removing
the 'arch' name from it and making it trully multi-arch, moving it to
the default lib directory, make both .a and .so variants, etc).

http://llvm-reviews.chandlerc.com/D2740

Files:
  lib/Driver/Tools.cpp

Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -1738,6 +1738,18 @@
     return TC.getArchName();
 }
 
+static void addClangRTLinux(
+    const ToolChain &TC, const ArgList &Args, ArgStringList &CmdArgs) {
+  // The runtime is located in the Linux library directory and has name
+  // "libclang_rt.<ArchName>.a".
+  SmallString<128> LibProfile(TC.getDriver().ResourceDir);
+  llvm::sys::path::append(
+      LibProfile, "lib", "linux",
+      Twine("libclang_rt.") + getArchNameForCompilerRTLib(TC) + ".a");
+
+  CmdArgs.push_back(Args.MakeArgString(LibProfile));
+}
+
 static void addProfileRTLinux(
     const ToolChain &TC, const ArgList &Args, ArgStringList &CmdArgs) {
   if (!(Args.hasArg(options::OPT_fprofile_arcs) ||
@@ -6690,7 +6702,19 @@
         CmdArgs.push_back("-lrt");
       }
 
-      AddLibgcc(ToolChain.getTriple(), D, CmdArgs, Args);
+      // Make use of compiler-rt if --rtlib option is used
+      ToolChain::RuntimeLibType RLT = ToolChain.GetRuntimeLibType(Args);
+
+      switch(RLT) {
+      case ToolChain::RLT_CompilerRT:
+        addClangRTLinux(ToolChain, Args, CmdArgs);
+        break;
+      case ToolChain::RLT_Libgcc:
+        AddLibgcc(ToolChain.getTriple(), D, CmdArgs, Args);
+        break;
+      default:
+        llvm_unreachable("Unknown RT-Lib type");
+      }
 
       if (Args.hasArg(options::OPT_pthread) ||
           Args.hasArg(options::OPT_pthreads) || OpenMP)
@@ -6700,8 +6724,12 @@
 
       if (Args.hasArg(options::OPT_static))
         CmdArgs.push_back("--end-group");
-      else
+      else if (RLT == ToolChain::RLT_Libgcc)
         AddLibgcc(ToolChain.getTriple(), D, CmdArgs, Args);
+      else if (RLT == ToolChain::RLT_CompilerRT)
+        addClangRTLinux(ToolChain, Args, CmdArgs);
+      else
+        llvm_unreachable("Unknown RT-Lib type");
     }
 
     if (!Args.hasArg(options::OPT_nostartfiles)) {
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D2740.1.patch
Type: text/x-patch
Size: 1971 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20140211/afaf1bc0/attachment.bin>