Elliott Hughes

the part that i don't think Arm supports specifically --- "Arm doesn't support just doing #define __ARM_FEATURE_CRC32 yourself, and specifically changed clang to prevent this".

sadly the exact same thing i showed you before :-( PWD=/proc/self/cwd prebuilts/remoteexecution-client/live//rewrapper --labels=type=compile,lang=cpp,compiler=clang --env_var_allowlist=PWD --exec_strategy=racing --platform=container-image=docker://gcr.io/androidbuild-re-dockerimage/android-build-remoteexec-image@sha256:582efb38f0c229ea39952fff9e132ccbe183e14869b39888010dacf56b360d62,Pool=default --compare=false prebuilts/clang/host/linux-x86/clang-r475365b/bin/clang -c -D__ANDROID_APEX__ -mthumb...

(here's another way in which projects can avoid this: just inline the instruction yourself with __asm__: https://github.com/madler/zlib/blob/master/crc32.c#L648 for example.)

What exact problem you have, if you compile 7-zip code without changes? if you just try to build as-is: In file included from external/lzma/C/7zCrc.c:94: prebuilts/clang/host/linux-x86/clang-r475365b/lib/clang/16.0.2/include/arm_acle.h:595:10: error: '__builtin_arm_crc32b' needs target feature crc return __builtin_arm_crc32b(__a, __b); ^ prebuilts/clang/host/linux-x86/clang-r475365b/lib/clang/16.0.2/include/arm_acle.h:605:10: error: '__builtin_arm_crc32w' needs target feature crc return __builtin_arm_crc32w(__a,...

any thoughts on this? is it worth me trying to come up with a patch myself and sending you a diff? or is armv7 dead to you?

armv7 support

ah, i didn't realize that. if you have a new enough compiler you could use #if __has_include(), but it looks like you try to support older compilers than that? one option here is that i just add a Windows.h to our copy of the code that just says #include <windows.h>. (that's actually what i did locally to investigate my other problems :-) ) oh, some random github project appears to have tested for mingw (which is what we -- and, i assume, everyone else -- use for cross-compilation) like this: ht...

#include <Windows.h> breaks cross-compilation