[LLD][COFF] Identify /GL object files which are inside libraries

[pzheng]

Summary

With D26647, we can already identify input object files compiled by cl.exe with
/GL. It seems to be helpful to do the same and print an error message for those
object files compiled with /GL but are inside libraries/archives too.

[pzheng]

minor change

[rnk]

lgtm

[thieta]

Thanks!

[pzheng]

Thanks for reviewing!

lld/COFF/Driver.cpp

void LinkerDriver::addArchiveBuffer(MemoryBufferRef mb, StringRef symName,
   }
 
   InputFile *obj;
   if (magic == file_magic::coff_object) {
     obj = make<ObjFile>(ctx, mb);
   } else if (magic == file_magic::bitcode) {
     obj =
         make<BitcodeFile>(ctx, mb, parentName, offsetInArchive, /*lazy=*/false);
+  } else if (magic == file_magic::coff_cl_gl_object) {
+    error(mb.getBufferIdentifier() +
+          ": is not a native COFF file. Recompile without /GL?");
+    return;
   } else {
     error("unknown file type: " + mb.getBufferIdentifier());
     return;
   }
 
   obj->parentName = parentName;
   ctx.symtab.addFile(obj);
   log("Loaded " + toString(obj) + " for " + symName);

lld/test/COFF/cl-gl.test

 # RUN: not lld-link /out:%t.exe /entry:main %S/Inputs/cl-gl.obj >& %t.log
 # RUN: FileCheck %s < %t.log
+# RUN: not lld-link /out:%t.exe /entry:main %S/Inputs/cl-gl.lib >& %t1.log
+# RUN: FileCheck %s < %t1.log
 
 # CHECK: is not a native COFF file. Recompile without /GL