[swift-dev] Building swift-llvm fails when using build-script to cross compile due to multiple -isysroot arguments being in CFLAGS

[Argyrios Kyrtzidis]

> On Mar 22, 2016, at 9:52 AM, Vedant Kumar <vsk at apple.com> wrote:
> 
> + swift-dev, Argyrios
> 
> 
>> On Mar 21, 2016, at 8:06 PM, Andrew Hyatt <ahyattdev at icloud.com> wrote:
>> 
>> swift-dev,
>> 
>> 5e342aa fixed the CFLAGS issue for swift-llvm and it now compiles fine for iOS. 
>> 
>> A remnant of the issue persists while building Swift. To get to that point I copied over two headers not present in the iOS SDK (crt_externs.h and histedit.h).
> 
> Andrew, which compiler invocations prompted you to copy these files over?
> 
> 
>> While building swift, I get the following error:
>> 
>> clang: error: invalid argument '-mmacosx-version-min=10.11' not allowed with '-miphoneos-version-min=7.0’
>> The arguments clang++ was launched with when the error occurred:
>> 
>> https://gist.github.com/ahyattdev/f5084b1ee8b320f90961
> 
> It looks like some of the logic in SourceKit's build scripts is tripping up.
> 
> Argyrios has done a lot of work on SourceKit, maybe he'll be able to spot the issue.

I don’t think SourceKit cpp files do anything special with CMake, are you sure this only shows up for SourceKit files, is everything else building fine ?
You could workaround by disabling building it with CMake variable, SWIFT_BUILD_SOURCEKIT=FALSE

> 
> 
> vedant
> 
>> Compiling LLVM works now, so maybe just one more change is needed to fix this build system issue for swift. 
>> 
>> Thanks you, Apple!
>> 
>> Also, great job on the 2.2 release and good luck with 3.0. 
>> 
>> Andrew Hyatt
>> ahyattdev at icloud.com
>> 
>>> On Mar 19, 2016, at 4:30 PM, Vedant Kumar <vsk at apple.com> wrote:
>>> 
>>> 
>>>> On Mar 19, 2016, at 12:05 PM, ChrisBieneman <beanz at apple.com> wrote:
>>>> 
>>>> [Adding Vedant directly]
>>>> 
>>>> I'm not super familiar with the swift build scripts, but I have a theory of what is going wrong. I think the problem is that compiler-rt is being built during the cross build, and it really shouldn't be.
>>>> 
>>>> The compiler-rt build system has some significant flaws, and it is being reworked to resolve them. The problem causing this is that we have a hacked up CMake build process that generates multiple cross-targeted binaries from a single build configuration. I believe that compiler-rt's built-in hacky cross-targeting is tripping over however swift is supporting cross-targeting, and it is falling over.
>>>> 
>>>> With the current state of compiler-rt the right way to build it for Darwin is to treat it as host content, and it will build the Darwin-cross libraries too. Then you can pull the cross-libraries out and put them into the device build.
>>> 
>>> Could you elaborate on what it means to treat it as host content? 
>>> 
>>> Is setting COMPILER_RT_HOST_TRIPLE and disabling COMPILER_RT_ENABLE_{I,TV,WATCH}OS the right thing to do?
>>> 
>>> 
>>>> Vedant, if you have questions feel free to swing by my office on Monday.
>>> 
>>> Will do.
>>> 
>>> 
>>> thanks,
>>> vedant
>>> 
>>>> -Chris
>>>> 
>>>> On Mar 19, 2016, at 10:11 AM, Andrew Hyatt via swift-dev <swift-dev at swift.org> wrote:
>>>> 
>>>>> (From /u/thegreatbeanz on reddit.com/r/swift)
>>>>> 
>>>>> So the problem here is actually that something has gone horribly wrong when configuring compiler- rt.
>>>>> You'll notice in the clang commands that it is building in this directory:
>>>>> clang_rt.builtins_armv7_10.4.dir
>>>>> What that means is it is building the clang_rt.10.4 archive which provides back ported library functions to OS X 10.4. Obviously 10.4 didn't support armv7 as an architecture, something has gone really wrong here.
>>>>> If you're on the latest swift it is probably a regression caused by 53f48f8. You need to email swift-dev to get support from Dmitri Gribenko and Vedant Kumar.
>>>>> Source: I wrote most of the compiler-rt builtin build system for Darwin.
>>>>> 
>>>>> Andrew Hyatt
>>>>> ahyattdev at icloud.com
>>>>> 
>>>>>> On Mar 19, 2016, at 9:26 AM, Andrew Hyatt via swift-dev <swift-dev at swift.org> wrote:
>>>>>> 
>>>>>> Building swift-llvm fails when using build-script to cross compile because build-script wrongly gives duplicate -isysroot arguments.
>>>>>> 
>>>>>> The full arguments that are given to clang by build-script while building LLVM are here: https://gist.github.com/ahyattdev/8ecc5d3808b9ee543a60
>>>>>> 
>>>>>> The command I use to build the compiler, using the latest sources from GitHub
>>>>>> 
>>>>>> utils/build-script -R -i -- --cross-compile-tools-deployment-targets "iphoneos-arm64 iphoneos-armv7 iphoneos-armv7s" --user-config-args="-DLLVM_ENABLE_BACKTRACES=Off"
>>>>>> 
>>>>>> This error occurs after the phase of building llvm for the host machine, and occurs during the cross compilation phase.
>>>>>> 
>>>>>> Andrew Hyatt
>>>>>> andythehyatt at gmail.com
>>>>>> 
>>>>>> _______________________________________________
>>>>>> swift-dev mailing list
>>>>>> swift-dev at swift.org
>>>>>> https://lists.swift.org/mailman/listinfo/swift-dev
>>>>> 
>>>>> _______________________________________________
>>>>> swift-dev mailing list
>>>>> swift-dev at swift.org
>>>>> https://lists.swift.org/mailman/listinfo/swift-dev
>>> 
>> 
>