[clang][Driver] Search lib32 on Linux/sparc64 with -m32

[ro]

Summary

When building current master on sparc64-unknown-linux-gnu (Debian 5.7.10), all 32-bit tests failed to link because the matching startup files and libraries weren't found. As on Linux/x86_64 they live in lib32 subdirectories.

This patch searches those directories as on x86 and ppc, allowing 32-bit links to succeed.

[phosek]

Would it be possible to add a test case in clang/test/Driver/linux-ld.c?

[ro]

Superceded by D90524.

clang/lib/Driver/ToolChains/Linux.cpp

if (Triple.isMIPS()) {
     // lib32 directory has a special meaning on MIPS targets.
     // It contains N32 ABI binaries. Use this folder if produce
     // code for N32 ABI only.
     if (tools::mips::hasMipsAbiArg(Args, "n32"))
       return "lib32";
     return Triple.isArch32Bit() ? "lib" : "lib64";
   }
 
-  // It happens that only x86 and PPC use the 'lib32' variant of oslibdir, and
-  // using that variant while targeting other architectures causes problems
-  // because the libraries are laid out in shared system roots that can't cope
-  // with a 'lib32' library search path being considered. So we only enable
-  // them when we know we may need it.
+  // It happens that only x86, PPC, and SPARC use the 'lib32' variant of
+  // oslibdir, and using that variant while targeting other architectures
+  // causes problems because the libraries are laid out in shared system
+  // roots that can't cope with a 'lib32' library search path being
+  // considered. So we only enable them when we know we may need it.
   //
   // FIXME: This is a bit of a hack. We should really unify this code for
   // reasoning about oslibdir spellings with the lib dir spellings in the
   // GCCInstallationDetector, but that is a more significant refactoring.
   if (Triple.getArch() == llvm::Triple::x86 ||
-      Triple.getArch() == llvm::Triple::ppc)
+      Triple.getArch() == llvm::Triple::ppc ||
+      Triple.getArch() == llvm::Triple::sparc)
     return "lib32";
 
   if (Triple.getArch() == llvm::Triple::x86_64 &&
       Triple.getEnvironment() == llvm::Triple::GNUX32)
     return "libx32";
 
   if (Triple.getArch() == llvm::Triple::riscv32)
     return "lib32";