Thank you everybody for your hints and suggestions. It helped me a lot! I have found the source of the crash I’ve been facing recently.
I run a program by passing argc=1 and argv=[“foo”]. For some reason the 'program under JIT’ was getting argc=2. Based on this number it creates an array of strings, to fulfil the CommandLine.arguments, which fails because there is only one string argument passed. So far I use a workaround: I call the main function with argc=1 and argv=[“foo”, “bar”] and everything works just fine. The next would be to actually utilize the _swift_stdlib_overrideUnsafeArgvArgc to pass arguments. However, there is one open question: why the JITted program sees ‘argc' as ‘2'? > On 6 Mar 2017, at 21:37, Robert Widmann <devteam.cod...@gmail.com> wrote: > > We used to have a callback in the standard library that would set the process > arguments, but that approach was fragile and would still have broken here. > Instead, we load the Swift standard library (a step we would have had to do > anyway) before entering main and call out to platform-specific functions that > grab command line arguments. Because you’re running on Linux, we’re asking > /proc/self/cmdline, but I’m not sure how exactly that interacts with the JIT. > If you’re going to JIT, you should at least follow our lead here by loading > the standard library which will in turn load the stubs. You can override the > platform-specific getters by calling out to > _swift_stdlib_overrideUnsafeArgvArgc. > >> On Mar 6, 2017, at 3:14 PM, Alex Denisov <1101.deb...@gmail.com> wrote: >> >>> The `main` entry point ought to be a standard C "main" function. The argv >>> argument is an UnsafeMutablePointer<UnsafeMutablePointer<Int8>?>, which >>> ought to be ABI-compatible with a char** in C. >> >> >> That was my assumption when I started, thank you for confirmation :) >> >>> When JIT'ing Swift, the value of argv doesn't matter because we replace the >>> process' arguments dynamically >>> https://github.com/apple/swift/blob/master/lib/Immediate/Immediate.cpp#L318. >> >> Hm, can you tell a bit more about this? I do not load the runtime, my crash >> may be caused by something not being initialized. >> Here is my simplified use-case: I compile a swift project with tests into >> bitcode, then I load the bitcode into memory, and then compile and execute a >> program using ORC JIT. >> >>> Do you have a trace for the crash? >> >> Sure, here it is: >> https://gist.github.com/AlexDenisov/2a8d9b0d391de73a97bce9e33a650f0f#file-trace-txt-L22-L42 >> >> >>> On 6 Mar 2017, at 20:14, Robert Widmann <devteam.cod...@gmail.com> wrote: >>> >>> %Sp is not an argument, it is the space necessary to hold a reference to >>> the CommandLine enumeration's static argv member. >>> >>> When JIT'ing Swift, the value of argv doesn't matter because we replace the >>> process' arguments dynamically >>> https://github.com/apple/swift/blob/master/lib/Immediate/Immediate.cpp#L318. >>> Do you have a trace for the crash? >>> >>> ~Robert Widmann >>> >>> 2017/03/06 12:33、Alex Denisov via swift-dev <swift-dev@swift.org> のメッセージ: >>> >>>> Hi there, >>>> >>>> I could not find a list for swift-corelibs-xctest so I am posting it here. >>>> >>>> I am trying to run tests based on XCTest >>>> (https://github.com/apple/swift-corelibs-xctest) using LLVM's JIT. >>>> Everything is working good so far. However, I am getting a crash. >>>> Based on a shallow investigation I can see that this is somehow related to >>>> the way Swift treats the command line arguments. Or, to be more precise, >>>> to the way I pass the arguments to the swift's 'main' function. >>>> >>>> What I did so far is not different from what I do to run C or C++ using >>>> JIT: >>>> >>>> auto main = ((int (*)(int, const char **))(intptr_t)mainPointer); >>>> const int argc = 1; >>>> const char *argv[] = { "some-name", NULL }; >>>> auto result = main(argc, argv); >>>> >>>> Based on what I see in the IR[1] the 'argv' has type "%Sp = type <{ i8* >>>> }>", which seems to be a struct with a pointer to something. >>>> >>>> So the question is: what is being passed as a second argument to the >>>> 'main' function of a swift program? >>>> >>>> Any other advice on JIT-ting Swift are more than welcome :) >>>> >>>> [1] https://gist.github.com/AlexDenisov/3c10540b544e82cfb6e58e1452491904 >>>> -- >>>> AlexDenisov >>>> Software Engineer, https://lowlevelbits.org >>>> >>>> _______________________________________________ >>>> swift-dev mailing list >>>> swift-dev@swift.org >>>> https://lists.swift.org/mailman/listinfo/swift-dev >> >> -- >> AlexDenisov >> Software Engineer, https://lowlevelbits.org >> > -- AlexDenisov Software Engineer, https://lowlevelbits.org _______________________________________________ swift-dev mailing list swift-dev@swift.org https://lists.swift.org/mailman/listinfo/swift-dev
