[PATCH] D155131: [clang][modules] Deserialize included files lazily

[Jan Svoboda via Phabricator via cfe-commits]

jansvoboda11 added a comment.

In D155131#4495489 <https://reviews.llvm.org/D155131#4495489>, @benlangmuir wrote:

> Now that it's not eagerly deserialized, should `Preprocessor::alreadyIncluded` call `HeaderInfo.getFileInfo(File)` to ensure the information is up to date?

It should, but `Preprocessor::alreadyIncluded()` is only called from `HeaderSearch::ShouldEnterIncludeFile()` and `Preprocessor::HandleHeaderIncludeOrImport()`, where `HeaderSearch::getFileInfo(File)` has already been called. But I agree it would be better to ensure that within `Preprocessor::alreadyIncluded()` itself. I'll try to include that in the next revision.

> Similarly, we expose the list of files in `Preprocessor::getIncludedFiles` -- is it okay if this list is incomplete?

That should be okay. This function only needs to return files included in the current module compilation, not all transitive includes.



================
Comment at: clang/lib/Serialization/ASTReader.cpp:1947
+    if (const FileEntry *FE = getFile(key))
+      Reader.getPreprocessor().getIncludedFiles().insert(FE);
+
----------------
benlangmuir wrote:
> `Reader.getPreprocessor().markIncluded`?
That would trigger infinite recursion, since that calls `getFileInfo()` which attempts to deserialize.


================
Comment at: clang/lib/Serialization/ASTWriter.cpp:2545
-    raw_svector_ostream Out(Buffer);
-    writeIncludedFiles(Out, PP);
-    RecordData::value_type Record[] = {PP_INCLUDED_FILES};
----------------
benlangmuir wrote:
> Can we remove `ASTWriter::writeIncludedFiles` now?
Yes, forgot about that, thanks.


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https://reviews.llvm.org/D155131