Missing assembly files on iOS

[theodelrieu]

Hello,

I had some trouble building this library on iOS (armv7/armv7s/x86/x86_64/armv8) and had to patch the build system files in order to add the relevant missing files.

I found this SO thread that saved me days of research, and I came up with the following patches:
patches.zip

Having no notion of Boost.Build, I monkey-patched the file once per arch, and have to apply the correct patch each time (not doing it by hand though).

I was thinking that you would have a better fix than me, and having it fixed upstream would be great!

[olk]

Could you provide a pull-request, please?

[theodelrieu]

I'd really like to, but I'm stuck at incorporating a single patch into my fork, even after reading the entire Boost.Build manual I don't understand what I'm doing wrong...

Here are the changes I've made to libs/context/build/Jamfile.v2:

actions gasarm64
{
    cpp -x assembler-with-cpp "$(>)" | as -arch arm64 -o "$(<)"
}

alias asm_sources
   : [ make asm/make_arm64_aapcs_macho_gas.o : asm/make_arm64_aapcs_macho_gas.S : @gasarm64 ]
     [ make asm/jump_arm64_aapcs_macho_gas.o : asm/jump_arm64_aapcs_macho_gas.S : @gasarm64 ]
     [ make asm/ontop_arm64_aapcs_macho_gas.o : asm/ontop_arm64_aapcs_macho_gas.S : @gasarm64 ]
   : <abi>aapcs
     <address-model>64
     <architecture>arm
     <binary-format>mach-o
     <toolset>clang
   ;

Here is the error I get (one for every assembly file):

Jamfile</Users/theo/Projects/boost/libs/context/build>.gasarm64 bin.v2/libs/context/build/asm/make_arm64_aapcs_macho_gas.o
clang: error: no input files
Jamfile</Users/theo/Projects/boost/libs/context/build>.gasarm64 bin.v2/libs/context/build/asm/jump_arm64_aapcs_macho_gas.o
clang: error: no input files
Jamfile</Users/theo/Projects/boost/libs/context/build>.gasarm64 bin.v2/libs/context/build/asm/ontop_arm64_aapcs_macho_gas.o
clang: error: no input files

If you could help me getting the first one right, I might be able to do the others in a sweep.

In the SO thread I've mentioned in the first post, there is a alias asm_context_sources. I have no idea how it made things work on my machine, nor why simply patching alias asm_sources instead did not...