760335 - Suppress Android gcc 4.4 warnings about "mangling of 'va_list' has changed in GCC 4.4"

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[Chris Peterson [:cpeterson]]

Android's gcc 4.4 dumps many "the mangling of 'va_list' has changed in GCC 4.4" warnings for system headers we don't control and va_list code that does not care about a stable name mangling ABI.

David Turner from the Android NDK team says [1]:

> there is no simple way to get rid of
> the warning that I know of (trust me I tried).
> The warning message comes from historical reasons. I believe it has been
> completely removed from the GCC 4.5 sources, but we're not using this yet.
> 
> For the record, the issue is that the mangling of 'va_list' has changed
> between gcc 4.2.1 and 4.4.0 (due to a late corrigenda to the ARM spec,
> previous versions of the toolchain mangled va_list the same a void*, which
> was wrong).
> 
> This however does *not* affect NDK-generated code because, very fortunately,
> none of the stable ABIs exposed by the NDK depend on this mangling (this has
> been checked carefully), so whichever toolchain you use, your code will run
> on all Android systems.

[1] https://groups.google.com/group/android-ndk/browse_thread/thread/9ab939743a968a83

Comment 1

[Chris Peterson [:cpeterson]]

Attachment: suppress-psabi-warnings.patch

Add gcc -Wno-psabi for Fennec's CXXFLAGS.

Comment 2

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Comment on attachment 629013 [details] [diff] [review]
suppress-psabi-warnings.patch

Yes please!

Comment 3

[Chris Peterson [:cpeterson]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/6a639340d3b6

Comment 4

[(no longer active)]

https://hg.mozilla.org/mozilla-central/rev/6a639340d3b6