2 files changed, 8 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/ObjectFilePCHContainerOperations.cpp b/clang/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
index c164cec5d94..5d97807316b 100644
--- a/clang/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
+++ b/clang/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
@@ -156,6 +156,8 @@ public:
         LangOpts.CurrentModule.empty() ? MainFileName : LangOpts.CurrentModule;
     CodeGenOpts.setDebugInfo(codegenoptions::FullDebugInfo);
     CodeGenOpts.setDebuggerTuning(CI.getCodeGenOpts().getDebuggerTuning());
+    CodeGenOpts.DebugPrefixMap =
+        CI.getInvocation().getCodeGenOpts().DebugPrefixMap;
   }
 
   ~PCHContainerGenerator() override = default;
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 8840e2ed004..f511fdcd87a 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -3264,6 +3264,12 @@ std::string CompilerInvocation::getModuleHash() const {
     code = ext->hashExtension(code);
   }
 
+  // When compiling with -gmodules, also hash -fdebug-prefix-map as it
+  // affects the debug info in the PCM.
+  if (getCodeGenOpts().DebugTypeExtRefs)
+    for (const auto &KeyValue : getCodeGenOpts().DebugPrefixMap)
+      code = hash_combine(code, KeyValue.first, KeyValue.second);
+
   // Extend the signature with the enabled sanitizers, if at least one is
   // enabled. Sanitizers which cannot affect AST generation aren't hashed.
   SanitizerSet SanHash = LangOpts->Sanitize;