Can't build for iOS arm64 (builtin OpenSSL error)

[vnen]

Trying to build for iPhone arm64 (on a Linux environment) gives error in the built-in OpenSSL. It does compile if I revert the last update (#4329). Somehow it compiles fine for iPhone armv7 architecture.

scons -j 1 p=iphone tools=no target=release_debug IPHONEPATH=/home/george/iostoolchain IPHONESDK=/home/george/iostoolchain/iPhoneOS9.2.sdk/ ios_triple=arm-apple-darwin11- bits=64
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
/home/george/iostoolchain/usr/bin/arm-apple-darwin11-clang -o drivers/builtin_openssl2/ssl/s3_cbc.iphone.opt.debug.64.o -c -DOPUS_ARM64_OPT -fno-objc-arc -arch arm64 -fmessage-length=0 -fno-strict-aliasing -fdiagnostics-print-source-range-info -fdiagnostics-show-category=id -fdiagnostics-parseable-fixits -Wno-trigraphs -fpascal-strings -Wmissing-prototypes -Wreturn-type -Wparentheses -Wswitch -Wno-unused-parameter -Wunused-variable -Wunused-value -Wno-shorten-64-to-32 -fvisibility=hidden -Wno-sign-conversion -MMD -MT dependencies -miphoneos-version-min=5.1.1 -isysroot /home/george/iostoolchain/iPhoneOS9.2.sdk/ -Os -DNS_BLOCK_ASSERTIONS=1 -Wall -DDEBUG_ENABLED -DNEED_LONG_INT -DLIBYUV_DISABLE_NEON -fblocks -DGAME_CENTER_ENABLED -DSTOREKIT_ENABLED -DICLOUD_ENABLED -DDEBUG_MEMORY_ENABLED -DIPHONE_ENABLED -DUNIX_ENABLED -DGLES2_ENABLED -DMPC_FIXED_POINT -fexceptions -DMUSEPACK_ENABLED -DOPENSSL_ENABLED -DSQUISH_ENABLED -DVORBIS_ENABLED -DOPUS_ENABLED -DTHEORA_ENABLED -DTHEORALIB_ENABLED -DPNG_ENABLED -DDDS_ENABLED -DPVR_ENABLED -DJPG_ENABLED -DWEBP_ENABLED -DSPEEX_ENABLED -DGDSCRIPT_ENABLED -DMINIZIP_ENABLED -DXML_ENABLED -DETC1_ENABLED -DPNG_ARM_NEON_OPT=0 -DOPENSSL_NO_ASM -DOPENSSL_THREADS -DL_ENDIAN -Icore -Icore/math -Itools -Idrivers -I. -Iplatform/iphone -Iplatform/iphone/include -I/home/george/iostoolchain/iPhoneOS9.2.sdk/usr/include -I/home/george/iostoolchain/iPhoneOS9.2.sdk/System/Library/Frameworks/OpenGLES.framework/Headers -I/home/george/iostoolchain/iPhoneOS9.2.sdk/System/Library/Frameworks/AudioUnit.framework/Headers -Idrivers/builtin_openssl2 -Idrivers/builtin_zlib/zlib -Idrivers/vorbis -Idrivers/builtin_openssl2/crypto -Idrivers/builtin_openssl2/openssl -Idrivers/builtin_openssl2/crypto/evp -Idrivers/builtin_openssl2/crypto/asn1 -Idrivers/builtin_openssl2/crypto/modes drivers/builtin_openssl2/ssl/s3_cbc.c
drivers/builtin_openssl2/ssl/s3_cbc.c:459:13: error: implicit declaration of function 'private_MD5_Init' is invalid in C99 [-Werror,-Wimplicit-function-declaration,2]
         if (MD5_Init((MD5_CTX *)md_state.c) <= 0)
             ^
drivers/builtin_openssl2/openssl/md5.h:115:18: note: expanded from macro 'MD5_Init'
 #define MD5_Init private_MD5_Init
                  ^
1 error generated.
scons: *** [drivers/builtin_openssl2/ssl/s3_cbc.iphone.opt.debug.64.o] Error 1
scons: building terminated because of errors.

Maybe with the next update will fix this, but will keep open as a reminder.

[akien-mga]

It seems blocking only when building with -Werror no? I see the same issue in Travis-CI logs but as a warning. IMO we shouldn't try to build external libraries with -Werror, we can't really fix their issues ourselves :)

[vnen]

Yes, you're right. However, it seems -Werror is default, as it's not in command line (also, it is not defined in any other platform, only for iOS arm64). Tried to add -Wno-error but it seems to not work in general, only if I specify a warning to no convert to error, such as -Wno-error=implicit-function-declaration.

[akien-mga]

I can't find any match for -Werror in the source code, that's weird. How did you see that it was defined only for iOS arm64? I don't see in the detect.py what would behave differently for armv7 and arm64 in this regard.

[vnen]

Well, it's a guess, as it is not defined for any platform, but for some reason is applied by default to iOS arm64, while not to armv7.

Also, if I revert the last OpenSSL update, it gives no error even though there's no relevant change in the erroring file. So I'm clueless.

[vnen]

I'm still clueless about what's going on here. Since the build still gives warnings, then -Werror is not defined, at least no for all warnings. From what I can infer, -Werror=implicit-function-declaration is enable by default, but only for arm64 and not for armv7 (since the latter only gives the warning while the former makes it an error).

I guess if we add -Wno-error=implicit-function-declaration to CFLAGS in platform/iphone/detect.py we can avoid this specific problem and hope there's no other hidden flag.

My Google-fu didn't help on this, I could not find any mention for default implicit flags like that.

[akien-mga]

I can confirm that it doesn't build on Travis either: https://travis-ci.org/GodotBuilder/godot-builds/jobs/128051707

[akien-mga]

Javascript seems to fail too with the same error, most likely because it's also built using clang: https://travis-ci.org/GodotBuilder/godot-builds/jobs/128253926

I guess the proper solution would be to add -Wno-error=implicit-function-declaration to the CFLAGS, not platform-dependent but directly in the SCsub of the builtin openssl driver. If we can somewhat make it with a local environment to avoid defining it for the rest of Godot's source, that would be best :)