1412254 - [Clang 5.0] dom/media/MediaDecoder.cpp:1555:6: error: lambda capture 'this' is not used [-Werror,-Wunused-lambda-capture]

Status: RESOLVED DUPLICATE of bug 1412547

(Core :: Audio/Video: Playback, defect, P3)

Description

[Jan Beich]

$ c++ -v
FreeBSD clang version 5.0.0 (tags/RELEASE_500/final 312559) (based on LLVM 5.0.0svn)
Target: x86_64-unknown-freebsd12.0
Thread model: posix
InstalledDir: /usr/bin

$ echo "ac_add_options --enable-warnings-as-errors # mimic MOZ_AUTOMATION" >>.mozconfig
$ ./mach build
[...]
In file included from objdir/dom/media/Unified_cpp_dom_media4.cpp:29:
dom/media/MediaDecoder.cpp:1555:6: error: lambda capture 'this' is not used
      [-Werror,-Wunused-lambda-capture]
    [this, self, str] (const nsACString& aString) {
     ^
dom/media/MediaDecoder.cpp:1559:6: error: lambda capture 'this' is not used
      [-Werror,-Wunused-lambda-capture]
    [this, self, str] () {
     ^
2 errors generated.

Comment 1

[Sylvestre Ledru [:Sylvestre]]

Are you going to fix it or should I ? :)

Comment 2

[Jan Beich]

(In reply to Sylvestre Ledru [:sylvestre] from comment #1)
> Are you going to fix it or should I ? :)

Please, take over. I prefer to focus on stuff that's hard to reproduce on Tier1 platforms. This one should be easy if you have Clang 5.0 or later.

Comment 3

[Jean-Yves Avenard [:jya]]

this *is* used here, by the DUMP macro

even in opt build...

looks to me that clang5 gets it wrong.

#define DUMP(x, ...) \
  printf_stderr("%s\n", nsPrintfCString("Decoder=%p " x, this, ##__VA_ARGS__).get())

Comment 4

[Jan Beich]

(In reply to Jean-Yves Avenard [:jya] from comment #3)
Did you miss https://hg.mozilla.org/integration/autoland/rev/61d60f1e1333 removed "this" reference from DUMP()?

Comment 5

[Jean-Yves Avenard [:jya]]

Ah no, I'm on central as of 5 minutes ago, this commit hasn't made it to central yet.