1393216 - When compiling for Windows with gcc, we encounter lots of #pragma warning's - which generate warnings

Status: RESOLVED FIXED

(Core :: General, defect)

Description

[Tom Ritter [:tjr] (OOTO until 9/2)]

MSVC supports #pragma warning() which is used to enable or disable warnings in a very nuanced way. https://msdn.microsoft.com/en-us/library/2c8f766e.aspx

gcc doesn't recognize these, and generates a warning saying 'Unknown Pragma'

Comment 1

[Tom Ritter [:tjr] (OOTO until 9/2)]

Attachment: Bug 1393216 Disable unknown pragma warnings when compiling for Windows with gcc

Review commit: https://reviewboard.mozilla.org/r/171810/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/171810/

Comment 2

[Tom Ritter [:tjr] (OOTO until 9/2)]

Try run:  https://treeherder.mozilla.org/#/jobs?repo=try&revision=d3499293ef67ca1d4000f2f7f905a13fe55f44b4

(The build will break, but the log shouldn't have any 'ignoring #pragma warning')

Comment 3

[Nathan Froyd [:froydnj]]

Comment on attachment 8900451 [details]
Bug 1393216 Disable unknown pragma warnings when compiling for Windows with gcc

https://reviewboard.mozilla.org/r/171810/#review177048

r=me with the change below.

::: build/moz.configure/warnings.configure:112
(Diff revision 1)
>  # We use mix of both POSIX and Win32 printf format across the tree, so format
>  # warnings are useless on mingw.
>  check_and_add_gcc_warning('-Wno-format',
>                            when=depends(target)(lambda t: t.kernel == 'WINNT'))
>  
> +# When compiling for Windows with gcc, we hit lots of #pragma warning's which gcc does not recognize

Nit: maybe "...lots of "#pragma warning"s, which is an MSVC-only pragma thatn GCC does not recognize."  The quoting of "#pragma warning" is important here, I think.

(Note that we disable the warning on clang-cl too, for much the same reason.)

Comment 4

[Tom Ritter [:tjr] (OOTO until 9/2)]

Comment on attachment 8900451 [details]
Bug 1393216 Disable unknown pragma warnings when compiling for Windows with gcc

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/171810/diff/1-2/

Comment 5

[Ryan VanderMeulen [:RyanVM]]

Autoland can't push this until all pending issues in MozReview are marked as resolved.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3dcae3969da1
Disable unknown pragma warnings when compiling for Windows with gcc r=froydnj

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/3dcae3969da1