[LLD][COFF] Add /inferasanlibs to lld-link as ignored flag

MSVC link.exe added this flag and MS STL started using this flag in
.drectve [1] when compiling with Clang with asan enabled, as reported
on #56300. This causes issues
with lld-link because it rejects any unknown flags in .drective sections.

As dc07867 noted that, when using Clang
as the driver it explicitly passes the proper asan libraries. Therefore
it should be acceptable to ignore this flag in lld-link to at least
unbreak building with clang-cl and linking with lld-link.

[1]: https://github.com/microsoft/STL/blob/faaf094ee16bcbfb2c8d612fdb9334bcdef2fd0a/stl/inc/__msvc_sanitizer_annotate_container.hpp#L35

Differential Revision: https://reviews.llvm.org/D149023

(cherry picked from commit 8fa0cfe)

Author: alvinhochun

lld/COFF/Driver.cpp

@@ -436,6 +436,8 @@ void LinkerDriver::parseDirectives(InputFile *file) {
     case OPT_editandcontinue:
     case OPT_guardsym:
     case OPT_throwingnew:
+    case OPT_inferasanlibs:
+    case OPT_inferasanlibs_no:
       break;
     default:
       error(arg->getSpelling() + " is not allowed in .drectve (" +
@@ -1924,6 +1926,9 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
       args.hasFlag(OPT_stdcall_fixup, OPT_stdcall_fixup_no, config->mingw);
   config->warnStdcallFixup = !args.hasArg(OPT_stdcall_fixup);
 
+  if (args.hasFlag(OPT_inferasanlibs, OPT_inferasanlibs_no, false))
+    warn("ignoring '/inferasanlibs', this flag is not supported");
+
   // Don't warn about long section names, such as .debug_info, for mingw or
   // when -debug:dwarf is requested.
   if (config->mingw || config->debugDwarf)

lld/COFF/Options.td

@@ -194,6 +194,9 @@ defm highentropyva : B<"highentropyva",
 defm incremental : B<"incremental",
                      "Keep original import library if contents are unchanged",
                      "Overwrite import library even if contents are unchanged">;
+defm inferasanlibs : B<"inferasanlibs",
+                       "Unused, generates a warning",
+                       "No effect (default)">;
 defm integritycheck : B<"integritycheck",
                         "Set FORCE_INTEGRITY bit in PE header",
                         "No effect (default)">;

lld/test/COFF/inferasanlibs-drectve.s

@@ -0,0 +1,16 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -triple=x86_64-windows %s -filetype=obj -o %t.obj
+
+# RUN: lld-link -dll -out:%t.dll -entry:entry %t.obj -subsystem:console 2>&1 | FileCheck --allow-empty --ignore-case %s
+
+# CHECK-NOT: ignoring unknown argument
+# CHECK-NOT: inferasanlibs
+# CHECK-NOT: is not allowed in .drectve
+
+  .global entry
+  .text
+entry:
+  ret
+  .section .drectve
+  .ascii " /INFERASANLIBS "

lld/test/COFF/inferasanlibs.test

@@ -0,0 +1,8 @@
+# RUN: yaml2obj %p/Inputs/ret42.yaml -o %t.obj
+
+# RUN: lld-link /out:%t.exe /entry:main %t.obj /inferasanlibs 2>&1 | FileCheck --check-prefix=POS %s
+# RUN: lld-link /out:%t.exe /entry:main %t.obj /inferasanlibs:no 2>&1 | FileCheck --allow-empty --check-prefix=NEG %s
+
+POS: ignoring '/inferasanlibs', this flag is not supported
+
+NEG-NOT: ignoring '/inferasanlibs', this flag is not supported