Fix two bugs for musl-libc on ARM

[zlei]

Summary

Bug #1: triples like armv7-pc-linux-musl uses wrong linker name ld-musl-armv7.so.1; the right name should be ld-musl-arm.so.1, disregarding the subarch field.

Bug #2: when compiler option -mhard-float is used, we should use the "hardfloat" linker, no matter whether the triple itself mentions "hardfloat".

[rengolin]

Hi Lei,

Thanks for the fix. A few comments. Also, please, add some tests.

cheers,
--renato

lib/Driver/ToolChains.cpp

4266

This is an early return, no need for brackets not the "else" below. Ex:

if (Android)
  return ...

if (musl) {
  ...
  return ...
}

[zlei]

Restructure the code and add a few tests.

[zlei]

@rengolin Thanks for your comments. Patch updated.

[rengolin]

LGTM. Thanks!

[zlei]

@rengolin Could you please apply this patch? I don't have the permission.

Thanks.

[rovka]

Hi Lei,

Renato is on vacation, so I committed this for you.

Regards,
Diana

[zlei]

@rovka Thanks a lot :)

lib/Driver/ToolChains.cpp

 }
 
 std::string Linux::getDynamicLinker(const ArgList &Args) const {
   const llvm::Triple::ArchType Arch = getArch();
   const llvm::Triple &Triple = getTriple();
 
   const enum Distro Distro = DetectDistro(getDriver(), Arch);
 
-  if (Triple.isAndroid())
+  if (Triple.isAndroid()) {
     return Triple.isArch64Bit() ? "/system/bin/linker64" : "/system/bin/linker";
-  else if (Triple.isMusl()) {
+  } else if (Triple.isMusl()) {
     std::string ArchName;
+    bool IsArm = false;
+
     switch (Arch) {
+    case llvm::Triple::arm:
     case llvm::Triple::thumb:
       ArchName = "arm";
+      IsArm = true;
       break;
+    case llvm::Triple::armeb:
     case llvm::Triple::thumbeb:
       ArchName = "armeb";
+      IsArm = true;
       break;
     default:
       ArchName = Triple.getArchName().str();
     }
-    if (Triple.getEnvironment() == llvm::Triple::MuslEABIHF)
+    if (IsArm &&
+        (Triple.getEnvironment() == llvm::Triple::MuslEABIHF ||
+         tools::arm::getARMFloatABI(*this, Args) == tools::arm::FloatABI::Hard))
       ArchName += "hf";
 
     return "/lib/ld-musl-" + ArchName + ".so.1";
   }
 
   std::string LibDir;
   std::string Loader;