[Dependency Scanning] Record header dependencies of Binary Swift module dependencies

These are meant to capture paths to the PCH files that a given module was built with.

lib/Serialization/SerializedModuleLoader.cpp

@@ -392,8 +392,8 @@ std::error_code SerializedModuleLoaderBase::openModuleFile(
   return std::error_code();
 }
 
-llvm::ErrorOr<llvm::StringSet<>>
-SerializedModuleLoaderBase::getModuleImportsOfModule(
+llvm::ErrorOr<SerializedModuleLoaderBase::BinaryModuleImports>
+SerializedModuleLoaderBase::getImportsOfModule(
     Twine modulePath, ModuleLoadingBehavior transitiveBehavior,
     bool isFramework, bool isRequiredOSSAModules, StringRef SDKName,
     StringRef packageName, llvm::vfs::FileSystem *fileSystem,
@@ -403,6 +403,7 @@ SerializedModuleLoaderBase::getModuleImportsOfModule(
     return moduleBuf.getError();
 
   llvm::StringSet<> importedModuleNames;
+  llvm::StringSet<> importedHeaders;
   // Load the module file without validation.
   std::shared_ptr<const ModuleFileSharedCore> loadedModuleFile;
   serialization::ValidationInfo loadInfo = ModuleFileSharedCore::load(
@@ -410,9 +411,10 @@ SerializedModuleLoaderBase::getModuleImportsOfModule(
       isRequiredOSSAModules, SDKName, recoverer, loadedModuleFile);
 
   for (const auto &dependency : loadedModuleFile->getDependencies()) {
-    // FIXME: Record header dependency?
-    if (dependency.isHeader())
+    if (dependency.isHeader()) {
+      importedHeaders.insert(dependency.RawPath);
       continue;
+    }
 
     ModuleLoadingBehavior dependencyTransitiveBehavior =
         loadedModuleFile->getTransitiveLoadingBehavior(
@@ -433,17 +435,13 @@ SerializedModuleLoaderBase::getModuleImportsOfModule(
     importedModuleNames.insert(moduleName);
   }
 
-  return importedModuleNames;
+  return SerializedModuleLoaderBase::BinaryModuleImports{importedModuleNames, importedHeaders};
 }
 
 llvm::ErrorOr<ModuleDependencyInfo>
 SerializedModuleLoaderBase::scanModuleFile(Twine modulePath, bool isFramework) {
   const std::string moduleDocPath;
   const std::string sourceInfoPath;
-  // Map the set of dependencies over to the "module dependencies".
-  auto dependencies = ModuleDependencyInfo::forSwiftBinaryModule(
-      modulePath.str(), moduleDocPath, sourceInfoPath, isFramework,
-      /*module-cache-key*/ "");
   // Some transitive dependencies of binary modules are not required to be
   // imported during normal builds.
   // TODO: This is worth revisiting for debugger purposes where
@@ -452,18 +450,37 @@ SerializedModuleLoaderBase::scanModuleFile(Twine modulePath, bool isFramework) {
   //       optional.
   ModuleLoadingBehavior transitiveLoadingBehavior =
       ModuleLoadingBehavior::Required;
-  auto importedModuleNames = getModuleImportsOfModule(
+  auto binaryModuleImports = getImportsOfModule(
       modulePath, transitiveLoadingBehavior, isFramework,
       isRequiredOSSAModules(), Ctx.LangOpts.SDKName, Ctx.LangOpts.PackageName,
       Ctx.SourceMgr.getFileSystem().get(),
       Ctx.SearchPathOpts.DeserializedPathRecoverer);
-  if (!importedModuleNames)
-    return importedModuleNames.getError();
+  if (!binaryModuleImports)
+    return binaryModuleImports.getError();
 
-  llvm::StringSet<> addedModuleNames;
-  for (const auto &importedModuleName : *importedModuleNames)
-    dependencies.addModuleImport(importedModuleName.getKey(),
-                                 &addedModuleNames);
+  auto importedModuleSet = binaryModuleImports.get().moduleImports;
+  std::vector<std::string> importedModuleNames;
+  importedModuleNames.reserve(importedModuleSet.size());
+  llvm::transform(importedModuleSet.keys(),
+                  std::back_inserter(importedModuleNames),
+                  [](llvm::StringRef N) {
+                     return N.str();
+                  });
+
+  auto importedHeaderSet = binaryModuleImports.get().headerImports;
+  std::vector<std::string> importedHeaders;
+  importedHeaders.reserve(importedHeaderSet.size());
+  llvm::transform(importedHeaderSet.keys(),
+                  std::back_inserter(importedHeaders),
+                  [](llvm::StringRef N) {
+                     return N.str();
+                  });
+
+  // Map the set of dependencies over to the "module dependencies".
+  auto dependencies = ModuleDependencyInfo::forSwiftBinaryModule(
+       modulePath.str(), moduleDocPath, sourceInfoPath,
+       importedModuleNames, importedHeaders, isFramework,
+       /*module-cache-key*/ "");
 
   return std::move(dependencies);
 }