[LLD][COFF] Print object file name for unsupported directives

[alvinhochun]

Summary

This is a small QoL improvement suggested by FrancescElies in
https://github.com/llvm/llvm-project/issues/56300#issuecomment-1172104966.

[alvinhochun]

Run clang-format

[mstorsjo]

LGTM, thanks!

lld/test/COFF/directives-unsupported.s

5

Curious; why the --ignore-case here?

[alvinhochun]

lld/test/COFF/directives-unsupported.s

5

A leftover from another test that I missed. I can remove it when committing.

lld/COFF/Driver.cpp

for (auto *arg : directives.args) {
     }
     // Only add flags here that link.exe accepts in
     // `#pragma comment(linker, "/flag")`-generated sections.
     case OPT_editandcontinue:
     case OPT_guardsym:
     case OPT_throwingnew:
       break;
     default:
-      error(arg->getSpelling() + " is not allowed in .drectve");
+      error(arg->getSpelling() + " is not allowed in .drectve (" +
+            toString(file) + ")");
     }
   }
 }
 
 // Find file from search paths. You can omit ".obj", this function takes
 // care of that. Note that the returned path is not guaranteed to exist.
 StringRef LinkerDriver::doFindFile(StringRef filename) {
   auto getFilename = [this](StringRef filename) -> StringRef {

lld/test/COFF/directives-unsupported.s

+# REQUIRES: x86
+
+# RUN: llvm-mc -triple=x86_64-windows %s -filetype=obj -o %t.obj
+
+# RUN: not lld-link -dll -out:%t.dll -entry:entry %t.obj -subsystem:console 2>&1 | FileCheck --ignore-case %s
+
+# CHECK: warning: ignoring unknown argument: -unknowndirectivename
+# CHECK: error: -unknowndirectivename is not allowed in .drectve ({{.*}}.obj)
+
+  .global entry
+  .text
+entry:
+  ret
+  .section .drectve
+  .ascii " -unknowndirectivename "