Commit Graph

3 Commits

Author SHA1 Message Date
Christopher Di Bella 0871954197 Revert "Revert "[clang][pp] adds '#pragma include_instead'""
Includes regression test for problem noted by @hans.
This reverts commit 973de71856.

Differential Revision: https://reviews.llvm.org/D106898
2021-07-29 19:21:43 +00:00
Hans Wennborg 973de71856 Revert "[clang][pp] adds '#pragma include_instead'"
> `#pragma clang include_instead(<header>)` is a pragma that can be used
> by system headers (and only system headers) to indicate to a tool that
> the file containing said pragma is an implementation-detail header and
> should not be directly included by user code.
>
> The library alternative is very messy code that can be seen in the first
> diff of D106124, and we'd rather avoid that with something more
> universal.
>
> This patch takes the first step by warning a user when they include a
> detail header in their code, and suggests alternative headers that the
> user should include instead. Future work will involve adding a fixit to
> automate the process, as well as cleaning up modules diagnostics to not
> suggest said detail headers. Other tools, such as clangd can also take
> advantage of this pragma to add the correct user headers.
>
> Differential Revision: https://reviews.llvm.org/D106394

This caused compiler crashes in Chromium builds involving PCH and an include
directive with macro expansion, when Token::getLiteralData() returned null. See
the code review for details.

This reverts commit e8a64e5491.
2021-07-27 17:29:48 +02:00
Christopher Di Bella e8a64e5491 [clang][pp] adds '#pragma include_instead'
`#pragma clang include_instead(<header>)` is a pragma that can be used
by system headers (and only system headers) to indicate to a tool that
the file containing said pragma is an implementation-detail header and
should not be directly included by user code.

The library alternative is very messy code that can be seen in the first
diff of D106124, and we'd rather avoid that with something more
universal.

This patch takes the first step by warning a user when they include a
detail header in their code, and suggests alternative headers that the
user should include instead. Future work will involve adding a fixit to
automate the process, as well as cleaning up modules diagnostics to not
suggest said detail headers. Other tools, such as clangd can also take
advantage of this pragma to add the correct user headers.

Differential Revision: https://reviews.llvm.org/D106394
2021-07-26 16:07:45 +00:00