[lld/mac] Address review feedback and improve a comment

[thakis]

Summary

I forgot to move the message() call around as requested in D103428
before committing that change. Move it now.

Also, improve the ordinal uniq'ing comment. I hadn't realized that the
distinct-but-identical files happen with --reproduce and not in general.

No behavior change.

[int3]

Thanks!

lld/MachO/Writer.cpp

714

lld/MachO/DriverUtils.cpp

DylibFile *macho::loadDylib(MemoryBufferRef mbref, DylibFile *umbrella,
   if (magic == file_magic::tapi_file) {
     Expected<std::unique_ptr<InterfaceFile>> result = TextAPIReader::get(mbref);
     if (!result) {
       error("could not load TAPI file at " + mbref.getBufferIdentifier() +
             ": " + toString(result.takeError()));
       return nullptr;
     }
     file = make<DylibFile>(**result, umbrella, isBundleLoader);
-    if (config->printEachFile)
-      message(toString(file));
 
     // parseReexports() can recursively call loadDylib(). That's fine since
     // we wrote DylibFile we just loaded to the loadDylib cache via the `file`
     // reference. But the recursive load can grow loadDylibs, so the `file`
     // reference might become invalid after parseReexports() -- so copy the
     // pointer it refers to before going on.
     newFile = file;
     if (newFile->exportingFile)
       newFile->parseReexports(**result);
   } else {
     assert(magic == file_magic::macho_dynamically_linked_shared_lib ||
            magic == file_magic::macho_dynamically_linked_shared_lib_stub ||
            magic == file_magic::macho_executable ||
            magic == file_magic::macho_bundle);
     file = make<DylibFile>(mbref, umbrella, isBundleLoader);
-    if (config->printEachFile)
-      message(toString(file));
 
     // parseLoadCommands() can also recursively call loadDylib(). See comment
     // in previous block for why this means we must copy `file` here.
     newFile = file;
     if (newFile->exportingFile)
       newFile->parseLoadCommands(mbref, umbrella);
   }
   return newFile;

lld/MachO/InputFiles.cpp

if (const load_command *cmd = findCommand(hdr, LC_ID_DYLIB)) {
     dylibName = reinterpret_cast<const char *>(cmd) + read32le(&c->dylib.name);
   } else if (!isBundleLoader) {
     // macho_executable and macho_bundle don't have LC_ID_DYLIB,
     // so it's OK.
     error("dylib " + toString(this) + " missing LC_ID_DYLIB load command");
     return;
   }
 
+  if (config->printEachFile)
+    message(toString(this));
+
   deadStrippable = hdr->flags & MH_DEAD_STRIPPABLE_DYLIB;
 
   if (!checkCompatibility(this))
     return;
 
   // Initialize symbols.
   exportingFile = isImplicitlyLinked(dylibName) ? this : umbrella;
   if (const load_command *cmd = findCommand(hdr, LC_DYLD_INFO_ONLY)) {
DylibFile::DylibFile(const InterfaceFile &interface, DylibFile *umbrella,
 
   if (umbrella == nullptr)
     umbrella = this;
 
   dylibName = saver.save(interface.getInstallName());
   compatibilityVersion = interface.getCompatibilityVersion().rawValue();
   currentVersion = interface.getCurrentVersion().rawValue();
 
+  if (config->printEachFile)
+    message(toString(this));
+
   if (!is_contained(skipPlatformChecks, dylibName) &&
       !is_contained(interface.targets(), config->platformInfo.target)) {
     error(toString(this) + " is incompatible with " +
           std::string(config->platformInfo.target));
     return;
   }
 
   exportingFile = isImplicitlyLinked(dylibName) ? this : umbrella;

lld/MachO/Writer.cpp

if (auto *dylibFile = dyn_cast<DylibFile>(file)) {
       if (!dylibFile->isReferenced() &&
           (!dylibFile->explicitlyLinked || dylibFile->deadStrippable ||
            config->deadStripDylibs))
         continue;
 
       // Several DylibFiles can have the same installName. Only emit a single
       // load command for that installName and give all these DylibFiles the
       // same ordinal.
-      // This can happen if:
+      // This can happen in several cases:
       // - a new framework could change its installName to an older
       //   framework name via an $ld$ symbol depending on platform_version
-      // - symlink (eg libpthread.tbd is a symlink to libSystem.tbd)
+      // - symlinks (for example, libpthread.tbd is a symlink to libSystem.tbd;
+      //   Foo.framework/Foo.tbd is usually a symlink to
+      //   Foo.framework/Versions/Current/Foo.tbd, where
+      //   Foo.framework/Versions/Current is usually a symlink to
+      //   Foo.framework/Versions/A)
       // - a framework can be linked both explicitly on the linker
       //   command line and implicitly as a reexport from a different
       //   framework. The re-export will usually point to the tbd file
       //   in Foo.framework/Versions/A/Foo.tbd, while the explicit link will
-      //   usually find Foo.framwork/Foo.tbd. These are usually two identical
-      //   but distinct files (concrete example: CFNetwork.framework, reexported
-      //   from CoreServices.framework).
+      //   usually find Foo.framwork/Foo.tbd. These are usually symlinks,
+      //   but in a --reproduce archive they will be identical but distinct
+      //   files.
       // In the first case, *semantically distinct* DylibFiles will have the
       // same installName.
       int64_t &ordinal = ordinalForInstallName[dylibFile->dylibName];
       if (ordinal) {
         dylibFile->ordinal = ordinal;
         continue;
       }