Index: llvm/docs/CommandGuide/dsymutil.rst
===================================================================
--- llvm/docs/CommandGuide/dsymutil.rst
+++ llvm/docs/CommandGuide/dsymutil.rst
@@ -71,6 +71,12 @@
 
  Specifies a ``path`` to prepend to all debug symbol object file paths.
 
+.. option:: --object-prefix-map=<prefix=remapped>
+
+ Remap object file paths (but no source paths) before processing.  Use
+ this for Clang objects where the module cache location was remapped using
+ ``-fdebug-prefix-map``; to help dsymutil find the Clang module cache.
+ 
 .. option:: --papertrail
 
  When running dsymutil as part of your build system, it can be desirable for
Index: llvm/include/llvm/DWARFLinker/DWARFLinker.h
===================================================================
--- llvm/include/llvm/DWARFLinker/DWARFLinker.h
+++ llvm/include/llvm/DWARFLinker/DWARFLinker.h
@@ -226,6 +226,7 @@
                                            StringRef Path)>
     objFileLoader;
 typedef std::map<std::string, std::string> swiftInterfacesMap;
+typedef std::map<std::string, std::string> objectPrefixMap;
 
 /// The core of the Dwarf linking logic.
 ///
@@ -311,6 +312,12 @@
     Options.ParseableSwiftInterfaces = Map;
   }
 
+  /// Set prefix map for objects.
+  void setObjectPrefixMap(objectPrefixMap *Map) {
+    Options.ObjectPrefixMap = Map;
+  }
+
+  
 private:
   /// Flags passed to DwarfLinker::lookForDIEsToKeep
   enum TraversalFlags {
@@ -780,6 +787,9 @@
     /// per compile unit, which is why this is a std::map.
     /// this is dsymutil specific fag.
     swiftInterfacesMap *ParseableSwiftInterfaces = nullptr;
+
+    /// A list of remappings to apply to file paths.
+    objectPrefixMap *ObjectPrefixMap = nullptr;
   } Options;
 };
 
Index: llvm/lib/DWARFLinker/DWARFLinker.cpp
===================================================================
--- llvm/lib/DWARFLinker/DWARFLinker.cpp
+++ llvm/lib/DWARFLinker/DWARFLinker.cpp
@@ -1914,6 +1914,14 @@
   return 0;
 }
 
+static std::string remapPath(StringRef Path,
+                             const objectPrefixMap &ObjectPrefixMap) {
+  for (const auto &Entry : ObjectPrefixMap)
+    if (Path.startswith(Entry.first))
+      return (Twine(Entry.second) + Path.substr(Entry.first.size())).str();
+  return Path.str();
+}
+
 bool DWARFLinker::registerModuleReference(
     DWARFDie CUDie, const DWARFUnit &Unit, const DwarfFile &File,
     OffsetsStringPool &StringPool, UniquingStringPool &UniquingStringPool,
@@ -1923,6 +1931,8 @@
       CUDie.find({dwarf::DW_AT_dwo_name, dwarf::DW_AT_GNU_dwo_name}), "");
   if (PCMfile.empty())
     return false;
+  if (Options.ObjectPrefixMap)
+    PCMfile = remapPath(PCMfile, *Options.ObjectPrefixMap);
 
   // Clang module DWARF skeleton CUs abuse this for the path to the module.
   uint64_t DwoId = getDwoId(CUDie, Unit);
Index: llvm/test/tools/dsymutil/X86/object-prefix-path.test
===================================================================
--- /dev/null
+++ llvm/test/tools/dsymutil/X86/object-prefix-path.test
@@ -0,0 +1,11 @@
+RUN: rm -rf %t.dir && mkdir %t.dir && mkdir %t.dir/ModuleCacheRenamed
+RUN: cp %p/../Inputs/module-warnings/1.o %t.dir
+RUN: cp %p/../Inputs/module-warnings/Foo.pcm %t.dir/ModuleCacheRenamed
+
+RUN: dsymutil -verify -f -oso-prepend-path=%t.dir -y \
+RUN:   %p/dummy-debug-map.map -o %t \
+RUN:   -object-prefix-map=/ModuleCache=/ModuleCacheRenamed \
+RUN:   2>&1 | FileCheck %s
+
+CHECK:     warning: {{.*}}Bar.pcm:
+CHECK-NOT: warning: {{.*}}Foo.pcm:
Index: llvm/test/tools/dsymutil/cmdline.test
===================================================================
--- llvm/test/tools/dsymutil/cmdline.test
+++ llvm/test/tools/dsymutil/cmdline.test
@@ -12,6 +12,7 @@
 HELP: -no-output
 HELP: -no-swiftmodule-timestamp
 HELP: -num-threads <threads>
+HELP: -object-prefix-map <prefix=remapped>
 HELP: -oso-prepend-path <path>
 HELP: -o <filename>
 HELP: -papertrail
Index: llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
===================================================================
--- llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
+++ llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
@@ -297,6 +297,7 @@
   remarks::RemarkLinker RL;
   if (!Options.RemarksPrependPath.empty())
     RL.setExternalFilePrependPath(Options.RemarksPrependPath);
+  GeneralLinker.setObjectPrefixMap(&Options.ObjectPrefixMap);
 
   std::function<StringRef(StringRef)> TranslationLambda = [&](StringRef Input) {
     assert(Options.Translator);
Index: llvm/tools/dsymutil/LinkUtils.h
===================================================================
--- llvm/tools/dsymutil/LinkUtils.h
+++ llvm/tools/dsymutil/LinkUtils.h
@@ -57,6 +57,9 @@
   /// -oso-prepend-path
   std::string PrependPath;
 
+  /// The -object-prefix-map.
+  std::map<std::string, std::string> ObjectPrefixMap;
+
   /// The Resources directory in the .dSYM bundle.
   Optional<std::string> ResourceDir;
 
Index: llvm/tools/dsymutil/Options.td
===================================================================
--- llvm/tools/dsymutil/Options.td
+++ llvm/tools/dsymutil/Options.td
@@ -110,6 +110,15 @@
   Group<grp_general>;
 def: Joined<["--", "-"], "oso-prepend-path=">, Alias<oso_prepend_path>;
 
+def object_prefix_map: Separate<["--", "-"], "object-prefix-map">,
+    MetaVarName<"<prefix=remapped>">,
+    HelpText<"Remap object file paths (but no source paths) before processing."
+             "Use this for Clang objects where the module cache location was"
+             "remapped using -fdebug-prefix-map; to help dsymutil"
+             "find the Clang module cache.">,
+    Group<grp_general>;
+def: Joined<["--", "-"], "object-prefix-map=">, Alias<object_prefix_map>;
+
 def symbolmap: Separate<["--", "-"], "symbol-map">,
   MetaVarName<"<bcsymbolmap>">,
   HelpText<"Updates the existing dSYMs inplace using symbol map specified.">,
Index: llvm/tools/dsymutil/dsymutil.cpp
===================================================================
--- llvm/tools/dsymutil/dsymutil.cpp
+++ llvm/tools/dsymutil/dsymutil.cpp
@@ -246,6 +246,12 @@
   if (opt::Arg *OsoPrependPath = Args.getLastArg(OPT_oso_prepend_path))
     Options.LinkOpts.PrependPath = OsoPrependPath->getValue();
 
+  for (const auto &Arg : Args.getAllArgValues(OPT_object_prefix_map)) {
+    auto Split = StringRef(Arg).split('=');
+    Options.LinkOpts.ObjectPrefixMap.insert(
+        {std::string(Split.first), std::string(Split.second)});
+  }
+
   if (opt::Arg *OutputFile = Args.getLastArg(OPT_output))
     Options.OutputFile = OutputFile->getValue();