Tighten the check for Tool name ( ar,nm,dlltool, lib)

[MaskRay]

Summary

This helps in creating canonical names for cross tool versions which may contain lib in their name. In Yocto this is common when creating multilib versions that lib32/lib/lib64 is added to canonical name to indicate multilib variant. This fails if we do not check the toolname to be at the end of string.

In multilib(lib32) case, the arm-pokymllib32-linux-gnueabi-llvm-ar (${TARGET_PREFIX}llvm-ar) gives:
qc: no such file or directory

Which is because when the llvm-ar symbol link's name contains "lib", it would be considered as llvm-lib:

[MaskRay]

On Debian, the package "llvm-8" installs llvm-ar at /usr/bin/llvm-ar-8. Maybe we should check either endswith("ar") or contains("ar-")? I think the existing _lower part is probably not necessary.

[MaskRay]

Oh, I think this may break llvm-dlltool.exe and llvm-ar.exe on Windows. We probably need a more sophisticated heuristic.

[rupprecht]

In D71030#1769588, @MaskRay wrote:

Oh, I think this may break llvm-dlltool.exe and llvm-ar.exe on Windows. We probably need a more sophisticated heuristic.

Does sys::path::stem(ToolName) convert llvm-dlltool.exe to llvm-dlltool? I don't have a Windows machine to check with, but it looks like it *might*.

[MaskRay]

Does sys::path::stem(ToolName) convert llvm-dlltool.exe

In D71030#1778131, @rupprecht wrote:

In D71030#1769588, @MaskRay wrote:

Oh, I think this may break llvm-dlltool.exe and llvm-ar.exe on Windows. We probably need a more sophisticated heuristic.

Does sys::path::stem(ToolName) convert llvm-dlltool.exe to llvm-dlltool? I don't have a Windows machine to check with, but it looks like it *might*.

It does, so it will break. Created D71302.

[MaskRay]

Superseded by D71302

llvm/tools/llvm-ar/llvm-ar.cpp

int main(int argc, char **argv) {
   InitLLVM X(argc, argv);
   ToolName = argv[0];
 
   llvm::InitializeAllTargetInfos();
   llvm::InitializeAllTargetMCs();
   llvm::InitializeAllAsmParsers();
 
   Stem = sys::path::stem(ToolName);
-  if (Stem.contains_lower("dlltool"))
+  if (Stem.endswith("dlltool") || Stem.contains("dlltool-"))
     return dlltoolDriverMain(makeArrayRef(argv, argc));
 
-  if (Stem.contains_lower("ranlib"))
+  if (Stem.endswith("ranlib") || Stem.contains("ranlib-"))
     return ranlib_main(argc, argv);
 
-  if (Stem.contains_lower("lib"))
+  if (Stem.endswith("lib") || Stem.contains("lib-"))
     return libDriverMain(makeArrayRef(argv, argc));
 
-  if (Stem.contains_lower("ar"))
+  if (Stem.endswith("ar") || Stem.contains("ar-"))
     return ar_main(argc, argv);
   fail("not ranlib, ar, lib or dlltool");
 }