[lld] [ELF] Parallelize input file loading (PR #191690)

[Peter Smith via llvm-commits]

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@@ -186,17 +201,20 @@ class LinkerDriver {
 private:
   Ctx &ctx;
   void createFiles(llvm::opt::InputArgList &args);
+  void loadFiles();
   void inferMachineType();
   template <class ELFT> void link(llvm::opt::InputArgList &args);
   template <class ELFT> void compileBitcodeFiles(bool skipLinkedOutput);
-  bool tryAddFatLTOFile(MemoryBufferRef mb, StringRef archiveName,
-                        uint64_t offsetInArchive, bool lazy);
   // True if we are in --whole-archive and --no-whole-archive.
   bool inWholeArchive = false;
 
   // True if we are in --start-lib and --end-lib.
   bool inLib = false;
 
+  // True inside createFiles(): defers to loadFiles().
+  bool deferLoad = false;
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smithp35 wrote:

Does this have to be a member variable? Just thinking that addFile() could have a deferLoad Parameter that is set to true within createFiles(). It would likely need threading through in a few places, like `addLibrary`.

I usually find local parameters a bit easier to reason about than class state, but if it means a large amount of code churn it may not be worth it.

I could be missing something important.

https://github.com/llvm/llvm-project/pull/191690