[clang] [clang][modulemap] Lazily load module maps by header name (PR #181916)

[Jan Svoboda via cfe-commits]

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@@ -1619,15 +1619,116 @@ StringRef HeaderSearch::getIncludeNameForHeader(const FileEntry *File) const {
   return It->second;
 }
 
+void HeaderSearch::buildHeaderCache(DirectoryEntryRef Dir,
+                                    ModuleMapDirectoryState &MMState) {
+  if (!MMState.ModuleMapFile)
+    return;
+  const modulemap::ModuleMapFile *ParsedMM =
+      ModMap.getParsedModuleMap(*MMState.ModuleMapFile);
+  if (!ParsedMM)
+    return;
+  const modulemap::ModuleMapFile *ParsedPrivateMM = nullptr;
+  if (MMState.PrivateModuleMapFile)
+    ParsedPrivateMM = ModMap.getParsedModuleMap(*MMState.PrivateModuleMapFile);
+
+  std::function<void(const modulemap::ModuleMapFile &, DirectoryEntryRef,
+                     StringRef)>
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jansvoboda11 wrote:

Can you please split these lambdas into separate functions? It's fairly difficult to keep track of function scopes here.

https://github.com/llvm/llvm-project/pull/181916