Cannot reduce bitcode size iOS

[Hamed Hosseini]

Hi 

I need to enable bitcode for my project but when I enabled the bitcode size of binary created goes up to 700 MB for the WebRTC file.

I use lipo -info to check the architecture of the file but only one arm64 exists.

I know in recent webrtc min requirement is ios 12, and 32-bit architecture was removed

but why the file size is huge for one architecture?

I use build_ios_libs.py --bitcode to build the xcframework file.

every time I run bitcode enable on a real device it takes a long time to copy the framework to the device.

I see in this repo he created a small file size binary with bitcode enabled.

How can I create like above link?

[Hamed Hosseini]

I can't understand why nobody answered this question. it's the basic and fundamental question and must place on the instruction in the document page but no one explained it!. 

[Medusa Development]

-- did you compare the bitcode size to the non bitcode size of your builds?

-- did you compile without debug or debug symbols?

--

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[Denis Slobodskoy]

Did anyone have a solution for a bitcode?

I also tried to use build_ios_libs.py  —bitcode , it was failed due to --llvm flag. Then I removed this from build/config/compiler/BUILD.gn:

    # TODO(hans): Remove this once Clang generates better optimized debug info
    # by default. https://crbug.com/765793
    cflags += [
      "-mllvm",
      "-instcombine-lower-dbg-declare=0",
    ]

It was able to create .xcframework after that, but library size is huge indeed, near 500 MB - and even if I try to use it, it failed on initialisation.

Without bitcode, library size is only 7.1 Mb, and debug version (which use -fembed-bitcode-marker instead) took 33.8 Mb so difference is really enormous.

Any ideas how to tame it?

Regards,

Denis Slobodskoy

среда, 28 июля 2021 г. в 19:50:03 UTC+10, medusade:

[Denis Slobodskoy]

Hello

I found an setting which caused library to expand dramatically, this line in build_ios_libs.py :

  gn_args.append('use_lld=' + ('false' if use_bitcode else 'true'))

If I remove it or set 'use_lld=true' unconditionally, library size become normal (~7Mb).

I did not use it in practice, but seems target library can be linked successfully in Xcode project.

It there any actual reason for use_lld=false, or it some artefact?

Regardsm

Denis Slobodskoy 

среда, 28 июля 2021 г. в 19:50:03 UTC+10, medusade:

-- did you compare the bitcode size to the non bitcode size of your builds?