[PATCH] D152741: [WPD] implement -fskip-vtable-filepaths

Wed Jun 21 10:30:51 PDT 2023

modimo added a comment.

In D152741#4438007 <https://reviews.llvm.org/D152741#4438007>, @tejohnson wrote:

> Ok what I missed is that you don't want to apply this to entire TUs, but rather just some paths that are header files, which may be included in many source files. So in your above example, you really only need to apply to the path of third-party/include/boost.h - is that correct?

Yep!

> That would mark class A, and therefore anything derived from it won't get devirtualized. I guess in your example above, you are trying to prevent the devirtualization in a.cpp since there are hidden overrides (class C) in boost.a native objects.

Exactly, we saw this scenario causing issues when enabling WPD.

> The example included with the patch applies the option to the source file of the test case, and therefore its entire TU. It would be helpful to have a test case structured like your example above, where the file path is just that of the header.

Makes sense and yeah the test case is confusing. Changed it to apply to just the header file.

> Maybe a better option name is something like -funknown-vtable-visibility-filepaths= ? It seems a bit more descriptive.

Sure, changed.

Repository:
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https://reviews.llvm.org/D152741