1 files changed, 12 insertions, 2 deletions
diff --git a/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp b/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
index 383a850301a1..086215e7a573 100644
--- a/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
+++ b/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
@@ -37,9 +37,13 @@ CompilerInvocation ModuleDepCollector::makeInvocationForModuleBuildWithoutPaths(
   CI.getLangOpts()->resetNonModularOptions();
   CI.getPreprocessorOpts().resetNonModularOptions();
 
-  // Remove options incompatible with explicit module build.
+  // Remove options incompatible with explicit module build or are likely to
+  // differ between identical modules discovered from different translation
+  // units.
   CI.getFrontendOpts().Inputs.clear();
   CI.getFrontendOpts().OutputFile.clear();
+  CI.getCodeGenOpts().MainFileName.clear();
+  CI.getCodeGenOpts().DwarfDebugFlags.clear();
 
   CI.getFrontendOpts().ProgramAction = frontend::GenerateModule;
   CI.getLangOpts()->ModuleName = Deps.ID.ModuleName;
@@ -233,7 +237,13 @@ ModuleID ModuleDepCollectorPP::handleTopLevelModule(const Module *M) {
                                    .getHeaderSearchInfo()
                                    .getModuleMap()
                                    .getModuleMapFileForUniquing(M);
-  MD.ClangModuleMapFile = std::string(ModuleMap ? ModuleMap->getName() : "");
+
+  if (ModuleMap) {
+    StringRef Path = ModuleMap->tryGetRealPathName();
+    if (Path.empty())
+      Path = ModuleMap->getName();
+    MD.ClangModuleMapFile = std::string(Path);
+  }
 
   serialization::ModuleFile *MF =
       MDC.ScanInstance.getASTReader()->getModuleManager().lookup(