[PATCH] D121533: [clang][deps] Fix traversal of precompiled dependencies

[Duncan P. N. Exon Smith via Phabricator via cfe-commits]

dexonsmith accepted this revision.
dexonsmith added a comment.
This revision is now accepted and ready to land.

LGTM, with another comment inline (up to you whether to do something with it).



================
Comment at: clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp:92
+  // List of module files to be processed.
+  llvm::SmallVector<std::string> Worklist{PrebuiltModuleFilename.str()};
+  PrebuiltModuleListener Listener(ModuleFiles, InputFiles, VisitInputFiles,
----------------
These filenames will usually be longer than `std::string`'s small storage, requiring separate heap allocations for each filename. Can the worklist just point at the stable pointer `StringMapEntry<std::string>*`, where a filename copy and heap allocation has already been made? (This has also has a nice side effect of handling 3x as many worklist items before needing to allocate, since the element size goes from 24B to 8B.)


================
Comment at: clang/test/ClangScanDeps/modules-pch-dangling.c:11
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+
----------------
`split-file` makes this so-called "unwieldy" testcase amazingly easy to read!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D121533/new/

https://reviews.llvm.org/D121533