Undefined symbols for architecture x86_64 iPhone Simulator

[jnavarrom]

We have a linker problem in the iPhone simulator with master. It works for devices but not for simulator. The problem is that for the simulator the flag -DCRYPTOPP_DISABLE_ASM is added to the compilation and then the flag CRYPTOPP_BOOL_ALIGN16 is set to 0 in the config.h, so CryptoPP::AlignedAllocate and CryptoPP::AlignedDeallocate aren't compiled:

Undefined symbols for architecture x86_64:
  "CryptoPP::AlignedAllocate(unsigned long)", referenced from:
      CryptoPP::AllocatorWithCleanup<unsigned int, true>::allocate(unsigned long, void const*) in libMEGASDK.a(megaapi_impl.o)
      ...
  "CryptoPP::AlignedDeallocate(void*)", referenced from:
      CryptoPP::AllocatorWithCleanup<unsigned int, true>::deallocate(void*, unsigned long) in libMEGASDK.a(megaapi_impl.o)
      ...
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

In our headers search path, the cryptopp config.h has the line https://github.com/weidai11/cryptopp/blob/master/config.h#L64 commented and I think for that the linker fails. This line should be commented for devices (armv7, armv7s and arm64) but not for simulator (x84_64).

The problem is that we have a fat library (for iPhone and iPhone simulator), the arch x86_64 built with -DCRYPTOPP_DISABLE_ASM and the others one without -DCRYPTOPP_DISABLE_ASM and then we have the same config.h (one library with all archs and one common include folder). We compile the cryptopp using the setenv-ios.sh scrript and the make -f GNUmakefile-cross lean -j 8.

We can fix the issue, compiling all the archs with -DCRYPTOPP_DISABLE_ASM and uncommented the line in the config.h, but we wouldn't take the adventage of use ASM where available.

Any advice to fix this issues?

[noloader]

the flag CRYPTOPP_BOOL_ALIGN16 is set to 0 in the config.h, so CryptoPP::AlignedAllocate and CryptoPP::AlignedDeallocate aren't compiled
...

Yeah, I seem to recall hitting that in the past. I thought we cleared it about 2 or 3 years ago by making both aligned and non-aligned available all the time. I can't find the issue/discussion at the moment. I found CryptoPP 5.6.2 - Undefined symbols for architecture x86_64 on the mailing list but I think there's a better discussion somewhere.

I see another report was opened about a year ago and it was closed due to lack of feedback.

I [still?] think the best way forward is to make both routines available all of the time to sidestep the problem. Let me see if I can get the change added without breaking things.

[noloader]

I think the changes on my testing fork are OK. I'm going to merge them.

$ source ./setenv-ios.sh iPhoneSimulator
Configuring for iPhoneSimulator (i386)
XCODE_SDK: iPhoneSimulator8.2.sdk
XCODE_DEVELOPER: /Applications/Xcode.app/Contents/Developer
XCODE_TOOLCHAIN: /Applications/Xcode.app/Contents/Developer/usr/bin
XCODE_DEVELOPER_TOP: /Applications/Xcode.app/Contents/Developer/Platforms/iPhone Simulator.platform/Developer
IOS_ARCH: i386
IOS_TOOLCHAIN: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefaul t.xctoolchain/usr/bin/
IOS_FLAGS:  -DCRYPTOPP_DISABLE_ASM -miphoneos-version-min=5 -DCRYPTOPP_DISABLE_ASM
IOS_SYSROOT: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.2.sdk
...

$ make -f GNUmakefile-cross -j 4
Here's what we found... IS_X86: 1, IS_X64: 0, IS_ARM32: 0, IS_ARMV8: 0
clang++ -DNDEBUG -g2 -O3 -fPIC -pipe -Wall -DCRYPTOPP_DISABLE_ASM -miphoneos-ver sion-min=5 -DCRYPTOPP_DISABLE_ASM -arch i386 -isysroot "/Applications/Xcode.app/ Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimul ator8.2.sdk" -stdlib=libc++ -c misc.cpp
...

And then:

$ nm libcryptopp.a 2>/dev/null | c++filt | grep -i allocate  | grep ' T '
00000940 T CryptoPP::AlignedAllocate(unsigned long)
000009d0 T CryptoPP::AlignedDeallocate(void*)
000009e0 T CryptoPP::UnalignedAllocate(unsigned long)
00000a70 T CryptoPP::UnalignedDeallocate(void*)

[noloader]

I'm fairly certain we cleared the issue at PR #780. Ping back if you still have trouble. I can re-open the issue.