1204919 - Build error in osx_corewlan.mm with --enable-macos-target=10.7 and --enable-warnings-as-errors (--enable-warnings-as-errors is now incompatible with --enable-rust)

Status: RESOLVED FIXED

Description

[:Ehsan Akhgari (Out of office 5/10-5/21)]

9:04.89 In file included from /Users/ehsan/moz/src/obj-ff-clang-plugin.noindex/netwerk/wifi/Unified_mm_netwerk_wifi0.mm:2:
 9:04.89 /Users/ehsan/moz/src/netwerk/wifi/osx_corewlan.mm:42:44: error: instance method '-scanForNetworksWithParameters:error:' not found (return type defaults to 'id') [-Werror,-Wobjc-method-access]
 9:04.89     id scanResult = [[CWI_class interface] scanForNetworksWithParameters:nil error:nil];
 9:04.89                                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 9:04.90 /Users/ehsan/moz/src/netwerk/wifi/osx_corewlan.mm:62:34: error: instance method '-bssidData' not found (return type defaults to 'id'); did you mean '-ssidData'? [-Werror,-Wobjc-method-access]
 9:04.91         NSData* data = [anObject bssidData];
 9:04.91                                  ^~~~~~~~~
 9:04.91                                  ssidData
 9:04.91 /Users/ehsan/moz/src/netwerk/wifi/osx_corewlan.mm:88:29: error: instance method '-rssi' not found (return type defaults to 'id') [-Werror,-Wobjc-method-access]
 9:04.92         signal = [[anObject rssi] intValue];
 9:04.92                             ^~~~

Comment 1

[:Ehsan Akhgari (Out of office 5/10-5/21)]

This API has been removed in 10.7: <https://developer.apple.com/library/mac/releasenotes/General/APIDiffsMacOSX10_9/CoreWLAN.html> so trying to build with any OS X SDK other than 10.6 fails and --enable-warnings-as-errors fails.  This is bad because --enable-rust requires an OS X SDK > 10.6, which means that turning on rust is now incompatible with --enable-warnings-as-errors.

Comment 2

[:Ehsan Akhgari (Out of office 5/10-5/21)]

Attachment: Fix builds with --enable-rust and --enable-errors-as-warnings on OS X

This is done by permitting compiler warnings in netwerk/wifi when targeting
OS X SDKs that have removed the APIs used there.

Comment 3

[Andrew McCreight [:mccr8]]

I'm getting this same error, but your patch doesn't fix it for me, presumably because I don't have the macos-target set. I do have |ac_add_options --enable-warnings-as-errors| but I don't have anything else interesting set in my mozconfig.

Comment 4

[Andrew McCreight [:mccr8]]

Getting rid of the |if| part of your patch fixes the build for me.

Comment 5

[Andrew McCreight [:mccr8]]

Attachment: Fix builds on newer versions of OS X with --enable-errors-as-warnings

This is a slightly modified version of Ehsan's patch.

Comment 6

[Mike Hommey [:glandium]]

Does using those APIs make any sense considering how few users of 10.6 we have? (also, how the hell does objc work? missing methods are _warnings_?)

Comment 7

[:Ehsan Akhgari (Out of office 5/10-5/21)]

(In reply to Mike Hommey [:glandium] from comment #6)
> Does using those APIs make any sense considering how few users of 10.6 we
> have?

I am not sure, but that's besides the point.  This bug is about fixing people's builds.  You should file a Necko bug if you want to find out the answers to that question!

> (also, how the hell does objc work? missing methods are _warnings_?)

In Objective C, you can call non-existing methods just fine.  They are implemented through message passing, and an object can choose to not respond to a message for reasons such as it not implementing the corresponding methods.

Comment 8

[Nicholas Nethercote [:njn]]

I can reproduce this locally. I will try to find a more precise way to ignore these warnings, e.g. via -Wobjc-method-access.

Comment 9

[:Ehsan Akhgari (Out of office 5/10-5/21)]

-Wno-error=objc-method-access is one option, I guess.

Comment 10

[Mike Hommey [:glandium]]

(In reply to Ehsan Akhgari (don't ask for review please) from comment #7)
> (In reply to Mike Hommey [:glandium] from comment #6)
> > Does using those APIs make any sense considering how few users of 10.6 we
> > have?
> 
> I am not sure, but that's besides the point.  This bug is about fixing
> people's builds.

People should not be using --enable-warnings-as-errors.

Comment 11

[Nicholas Nethercote [:njn]]

Attachment: Build osx_corewlan.mm with -Wno-objc-method-access to avoid bustage on some machines in warnings-on-errors builds

Let's carve out this exception with a scalpel rather than an axe :)

Comment 12

[Nicholas Nethercote [:njn]]

Attachment: Build osx_corewlan.mm with -Wno-erro to avoid bustage on some machines in warnings-on-errors builds

Ehsan is right; -Wno-error=objc-method-access is even better.

Comment 13

[Nicholas Nethercote [:njn]]

> People should not be using --enable-warnings-as-errors.

I think it's a reasonable thing to do as long as you're building on tier 1 platforms with standard compilers. I've been doing it locally for the past few weeks.

Comment 14

[:Ehsan Akhgari (Out of office 5/10-5/21)]

(In reply to Nicholas Nethercote [:njn] from comment #13)
> > People should not be using --enable-warnings-as-errors.
> 
> I think it's a reasonable thing to do as long as you're building on tier 1
> platforms with standard compilers. I've been doing it locally for the past
> few weeks.

I have been doing it for years.  It's an entirely reasonable thing to do, if you're interested in catching new warnings that will be treated as errors locally first.  Also, this bug affects "people" and machines equally.

Comment 15

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/248f5a4b7e0e

Comment 16

[Steven Michaud [:smichaud] (Retired)]

(Following up comment #7)

> Does using those APIs make any sense considering how few users of 10.6 we have?

Our number of OS X 10.6 users is actually quite large -- currently about 17% of our Mac user base.

Comment 17

[Wes Kocher (:KWierso)]

https://hg.mozilla.org/mozilla-central/rev/248f5a4b7e0e