diff --git a/lld/MachO/Arch/ARM64.cpp b/lld/MachO/Arch/ARM64.cpp
--- a/lld/MachO/Arch/ARM64.cpp
+++ b/lld/MachO/Arch/ARM64.cpp
@@ -624,7 +624,8 @@
 
   auto isValidOffset = [&](uint64_t offset) {
     if (offset < sectionAddr || offset >= sectionAddr + section->getSize()) {
-      error("linker optimization hint spans multiple sections");
+      error(toString(&obj) +
+            ": linker optimization hint spans multiple sections");
       return false;
     }
     return true;
diff --git a/lld/MachO/InputFiles.h b/lld/MachO/InputFiles.h
--- a/lld/MachO/InputFiles.h
+++ b/lld/MachO/InputFiles.h
@@ -269,6 +269,8 @@
   void handleLDHideSymbol(StringRef name, StringRef originalName);
   void checkAppExtensionSafety(bool dylibIsAppExtensionSafe) const;
   void parseExportedSymbols(uint32_t offset, uint32_t size);
+  void loadReexport(StringRef path, DylibFile *umbrella,
+                    const llvm::MachO::InterfaceFile *currentTopLevelTapi);
 
   llvm::DenseSet<llvm::CachedHashStringRef> hiddenSymbols;
 };
diff --git a/lld/MachO/InputFiles.cpp b/lld/MachO/InputFiles.cpp
--- a/lld/MachO/InputFiles.cpp
+++ b/lld/MachO/InputFiles.cpp
@@ -1648,11 +1648,12 @@
   return false;
 }
 
-static void loadReexport(StringRef path, DylibFile *umbrella,
+void DylibFile::loadReexport(StringRef path, DylibFile *umbrella,
                          const InterfaceFile *currentTopLevelTapi) {
   DylibFile *reexport = findDylib(path, umbrella, currentTopLevelTapi);
   if (!reexport)
-    error("unable to locate re-export with install name " + path);
+    error(toString(this) + ": unable to locate re-export with install name " +
+          path);
 }
 
 DylibFile::DylibFile(MemoryBufferRef mb, DylibFile *umbrella,
@@ -1676,7 +1677,7 @@
   } 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");
+    error(toString(this) + ": dylib missing LC_ID_DYLIB load command");
     return;
   }
 
@@ -1705,8 +1706,8 @@
   if (dyldInfo && exportsTrie) {
     // It's unclear what should happen in this case. Maybe we should only error
     // out if the two load commands refer to different data?
-    error("dylib " + toString(this) +
-          " has both LC_DYLD_INFO_ONLY and LC_DYLD_EXPORTS_TRIE");
+    error(toString(this) +
+          ": dylib has both LC_DYLD_INFO_ONLY and LC_DYLD_EXPORTS_TRIE");
     return;
   } else if (dyldInfo) {
     parseExportedSymbols(dyldInfo->export_off, dyldInfo->export_size);
@@ -2003,13 +2004,14 @@
 
   VersionTuple start;
   if (start.tryParse(startVersion)) {
-    warn("failed to parse start version, symbol '" + originalName +
-         "' ignored");
+    warn(toString(this) + ": failed to parse start version, symbol '" +
+         originalName + "' ignored");
     return;
   }
   VersionTuple end;
   if (end.tryParse(endVersion)) {
-    warn("failed to parse end version, symbol '" + originalName + "' ignored");
+    warn(toString(this) + ": failed to parse end version, symbol '" +
+         originalName + "' ignored");
     return;
   }
   if (config->platformInfo.minimum < start ||
@@ -2022,7 +2024,8 @@
   if (!compatVersion.empty()) {
     VersionTuple cVersion;
     if (cVersion.tryParse(compatVersion)) {
-      warn("failed to parse compatibility version, symbol '" + originalName +
+      warn(toString(this) +
+           ": failed to parse compatibility version, symbol '" + originalName +
            "' ignored");
       return;
     }
@@ -2061,7 +2064,8 @@
   std::tie(condition, installName) = name.split('$');
   VersionTuple version;
   if (!condition.consume_front("os") || version.tryParse(condition))
-    warn("failed to parse os version, symbol '" + originalName + "' ignored");
+    warn(toString(this) + ": failed to parse os version, symbol '" +
+         originalName + "' ignored");
   else if (version == config->platformInfo.minimum)
     this->installName = saver().save(installName);
 }
@@ -2076,7 +2080,7 @@
     std::tie(minVersion, symbolName) = name.split('$');
     VersionTuple versionTup;
     if (versionTup.tryParse(minVersion)) {
-      warn("Failed to parse hidden version, symbol `" + originalName +
+      warn(toString(this) + ": failed to parse hidden version, symbol `" + originalName +
            "` ignored.");
       return;
     }
diff --git a/lld/test/MachO/invalid/invalid-loh.s b/lld/test/MachO/invalid/invalid-loh.s
--- a/lld/test/MachO/invalid/invalid-loh.s
+++ b/lld/test/MachO/invalid/invalid-loh.s
@@ -1,9 +1,10 @@
 # REQUIRES: aarch64
+# RUN: rm -rf %t; mkdir -p %t
 
-# RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %s -o %t.o
-# RUN: not %lld -arch arm64 %t.o -o /dev/null 2>&1 | FileCheck %s
+# RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %s -o %t/test.o
+# RUN: not %lld -arch arm64 %t/test.o -o /dev/null 2>&1 | FileCheck %s
 
-# CHECK: error: linker optimization hint spans multiple sections
+# CHECK: error: {{.*}}test.o: linker optimization hint spans multiple sections
 
 .globl _main
 _main:
diff --git a/lld/test/MachO/invalid/no-id-dylink.yaml b/lld/test/MachO/invalid/no-id-dylink.yaml
--- a/lld/test/MachO/invalid/no-id-dylink.yaml
+++ b/lld/test/MachO/invalid/no-id-dylink.yaml
@@ -3,7 +3,7 @@
 # RUN: yaml2obj %s -o %t/libnoid.dylib
 # RUN: echo ".globl _main; .text; _main: ret" | llvm-mc -filetype=obj -triple=x86_64-apple-darwin -o %t/no-id-dylink.o
 # RUN: not %lld -o %t/no-id-dylink -L%t -lnoid %t/no-id-dylink.o 2>&1 | FileCheck %s
-# CHECK: error: dylib {{.*}}libnoid.dylib missing LC_ID_DYLIB load command
+# CHECK: error: {{.*}}libnoid.dylib: dylib missing LC_ID_DYLIB load command
 
 ## This YAML file was originally generated from linking the following source
 ## input with ld64 and passing the resulting binary through obj2yaml:
diff --git a/lld/test/MachO/link-search-at-executable-path.s b/lld/test/MachO/link-search-at-executable-path.s
--- a/lld/test/MachO/link-search-at-executable-path.s
+++ b/lld/test/MachO/link-search-at-executable-path.s
@@ -20,7 +20,7 @@
 
 ## It also doesn't help if the needed reexport isn't next to the library.
 # RUN: not %lld -lSystem %t/main.o %t/libbar.dylib -o %t/test 2>&1 | FileCheck --check-prefix=ERR %s
-# ERR: error: unable to locate re-export with install name @executable_path/libfoo.dylib
+# ERR: error: {{.*}}libbar.dylib: unable to locate re-export with install name @executable_path/libfoo.dylib
 
 #--- foo.s
 .globl _foo
diff --git a/lld/test/MachO/special-symbol-ld-install-name.s b/lld/test/MachO/special-symbol-ld-install-name.s
--- a/lld/test/MachO/special-symbol-ld-install-name.s
+++ b/lld/test/MachO/special-symbol-ld-install-name.s
@@ -23,7 +23,7 @@
 # RUN: %no-fatal-warnings-lld -o %t/libfoo3.dylib %t/libLDInstallNameInvalid.tbd %t/foo.o -dylib \
 # RUN:  -platform_version macos 11.0.0 11.0.0 2>&1 | FileCheck --check-prefix=INVALID-VERSION %s
 
-# INVALID-VERSION: failed to parse os version, symbol '$ld$install_name$os11.a$/New' ignored
+# INVALID-VERSION: libLDInstallNameInvalid.tbd(/Old): failed to parse os version, symbol '$ld$install_name$os11.a$/New' ignored
 
 ## Case 3: If there's another library that has '/New' as its original
 ## install_name, we should take current-version and compatibility-version from
diff --git a/lld/test/MachO/special-symbol-ld-previous.s b/lld/test/MachO/special-symbol-ld-previous.s
--- a/lld/test/MachO/special-symbol-ld-previous.s
+++ b/lld/test/MachO/special-symbol-ld-previous.s
@@ -59,9 +59,9 @@
 # RUN: %no-fatal-warnings-lld -o %t/libfoo1.dylib %t/libLDPreviousInvalid.tbd %t/ref_xxx.o -dylib \
 # RUN:  -platform_version macos 11.0.0 11.0.0 2>&1 | FileCheck --check-prefix=INVALID-VERSION %s
 
-# INVALID-VERSION-DAG: failed to parse start version, symbol '$ld$previous$/New$1.2.3$1$3.a$14.0$$' ignored
-# INVALID-VERSION-DAG: failed to parse end version, symbol '$ld$previous$/New$1.2.3$1$3.0$14.b$$' ignored
-# INVALID-VERSION-DAG: failed to parse compatibility version, symbol '$ld$previous$/New$1.2.c$1$3.0$14.0$$' ignored
+# INVALID-VERSION-DAG: libLDPreviousInvalid.tbd(/Old): failed to parse start version, symbol '$ld$previous$/New$1.2.3$1$3.a$14.0$$' ignored
+# INVALID-VERSION-DAG: libLDPreviousInvalid.tbd(/Old): failed to parse end version, symbol '$ld$previous$/New$1.2.3$1$3.0$14.b$$' ignored
+# INVALID-VERSION-DAG: libLDPreviousInvalid.tbd(/Old): failed to parse compatibility version, symbol '$ld$previous$/New$1.2.c$1$3.0$14.0$$' ignored
 
 #--- ref_xxx.s
 .long	_xxx@GOTPCREL
diff --git a/lld/test/MachO/sub-library.s b/lld/test/MachO/sub-library.s
--- a/lld/test/MachO/sub-library.s
+++ b/lld/test/MachO/sub-library.s
@@ -58,7 +58,7 @@
 # RUN: rm -f %t/libgoodbye.dylib
 # RUN: not %lld -o %t/sub-library -L%t -lsuper %t/sub-library.o 2>&1 \
 # RUN:  | FileCheck %s --check-prefix=MISSING-REEXPORT -DDIR=%t
-# MISSING-REEXPORT: error: unable to locate re-export with install name [[DIR]]/libgoodbye.dylib
+# MISSING-REEXPORT: error: {{.*}}libsuper.dylib: unable to locate re-export with install name [[DIR]]/libgoodbye.dylib
 
 
 ## We can match dylibs without extensions too.