[PATCH] D83652: Merge some of the PCH object support with modular codegen

[Luboš Luňák via Phabricator via cfe-commits]

llunak added a comment.

The patch is incomplete, isn't it? It removes DeclIsFromPCHWithObjectFile(), but it's still called from ASTContext::DeclMustBeEmitted(). The description also mentions updating of the pch-codegen test, but that's not included.

But assuming this is intended to replace the D48426 <https://reviews.llvm.org/D48426> functionality with modular codegen, I mentioned already in D69778 <https://reviews.llvm.org/D69778> (starting with 'Mar 17 2020, 10:59 PM') that it's a question if this is possible. Modular codegen is a much bigger hammer than  D48426 <https://reviews.llvm.org/D48426> and it has also bigger possible problems: Possibly making compilation actually slower (even f63556d8b44b209e741833b0e6be3f8e72a1d91a mentions this), and possibly causing build problems because of referencing private symbols.  D48426 <https://reviews.llvm.org/D48426> is much smaller both in gains and in problems (=safer).

> Do either of you know if it'd be practical to move to something more similar to .pcm handling, where the pch itself is passed to the compilation, rather than homed as a side effect of compiling some other source file?

Do you mean dropping compatibility with 'cl.exe /Yc'?


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https://reviews.llvm.org/D83652