Clarification: I was too aggressive about cleaning up the output from the link step in the example below. Here’s what happened:
fatal error: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: can't stat file output file: /Users/jim/Workspace/myproject/build/xcode-osx/obj/modules/pacing/Debug/libpacing.a (No such file or directory) This error was generated by the command that was supposed to assemble libpacing.a; hence, my guess that the file was being deleted out from under the command. Note that the full path to the output file does in fact exist. > On Sep 17, 2018, at 5:32 PM, Jim Wong <j...@airtime.com> wrote: > > Folks, > > I’m working with a very large CMakeLists.txt, and I’m having trouble > generating a working > Xcode project from it (the Ninja and Make generators seem to work fine). > > What’s happening is that the post-build step associated with each of the > targets in > XCODE_DEPEND_HELPER.make is aggressively deleting a bunch of other targets, > including > some that either a) haven’t been built yet; or b) are in the process of being > built. > The former isn’t an issue, but the latter is: I get a build error when this > happens. > > Here’s a *very* cut-down look at what’s happening: > > Showing All Messages, Filtering for "libpacing.a". > PhaseScriptExecution CMake\ PostBuild\ Rules > build/xcode-osx/cmake/osx/Release/project.build/Debug/ApiVideo_CodecsVideo_Codecs_Api.build/Script-62A3C733E930414E85209FFB.sh > cd /Users/jim/Workspace/myproject > /bin/sh -c > /Users/jim/Workspace/myproject/build/xcode-osx/cmake/osx/Release/project.build/Debug/ApiVideo_CodecsVideo_Codecs_Api.build/Script-62A3C733E930414E85209FFB.sh > /bin/rm -f > /Users/jim/Workspace/myproject/build/xcode-osx/obj/modules/pacing/Debug/libpacing.a > > PhaseScriptExecution CMake\ PostBuild\ Rules > build/xcode-osx/cmake/osx/Release/project.build/Debug/Rtc_BaseAudio_Format_To_String.build/Script-61E5555E2FB7443C905B7CC4.sh > cd /Users/jim/Workspace/myproject > /bin/sh -c > /Users/jim/Workspace/myproject/build/xcode-osx/cmake/osx/Release/project.build/Debug/Rtc_BaseAudio_Format_To_String.build/Script-61E5555E2FB7443C905B7CC4.sh > /bin/rm -f > /Users/jim/Workspace/myproject/build/xcode-osx/obj/modules/pacing/Debug/libpacing.a > > *** there are a lot more instances of this pattern *** > > Libtool build/xcode-osx/obj/modules/pacing/Debug/libpacing.a normal x86_64 > > /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool > -static -arch_only x86_64 -syslibroot > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk > -L/Users/jim/Workspace/myproject/build/xcode-osx/obj/modules/pacing/Debug > -filelist > /Users/jim/Workspace/myproject/build/xcode-osx/cmake/osx/Release/project.build/Debug/ModulesPacingPacing.build/Objects-normal/x86_64/pacing.LinkFileList > > /Users/jim/Workspace/myproject/build/xcode-osx/cmake/osx/Release/project.build/Debug/Rtc_BaseRtc_Event.build/Objects-normal/x86_64/event.o > -o > /Users/jim/Workspace/myproject/build/xcode-osx/obj/modules/pacing/Debug/libpacing.a > fatal error: > /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: > can't stat file output file: > /Users/jim/Workspace/myproject/build/xcode-osx/obj/modules/pacing/Debug/libpacing.a > (No such file or directory) > > *** here we’re dead *** > > *** deleting libpacing.a one more time for good measure *** > > PhaseScriptExecution CMake\ PostBuild\ Rules > build/xcode-osx/cmake/osx/Release/project.build/Debug/ModulesAudio_ProcessingAgc2Fixed_Digital.build/Script-A48E7039684F4F828D6DC3DE.sh > cd /Users/jim/Workspace/myproject > /bin/sh -c > /Users/jim/Workspace/myproject/build/xcode-osx/cmake/osx/Release/project.build/Debug/ModulesAudio_ProcessingAgc2Fixed_Digital.build/Script-A48E7039684F4F828D6DC3DE.sh > /bin/rm -f > /Users/jim/Workspace/myproject/build/xcode-osx/obj/modules/pacing/Debug/libpacing.a > > As you can see, Xcode is complaining about the file libpacing.a not existing > at the same time > it’s trying to link that very file. My guess has been that the file is > getting deleted out > from under the linker. I’m not sure how to resolve that issue, however. > > Part of the issue here is that we’re working with a very large CMake file > that was generated > from the output of another build system (don’t ask), so narrowing this down > to an easily > replicable scenario has been challenging. As far as I can tell, the problem > is as follows: > > 1. Target A is an object library that is used by several targets. > 2. Target A* is the post-build target for A. > 3. Target B is an executable that depends on A. > 4. Target C is different library that B depends on. > > Notably, C does not depend on A; nor does A depend on C. > > After A is built by Xcode, it builds A* in XCODE_DEPEND_HELPER.make. Because > B depends on A, > A* depends on B in this Makefile. As a result, B’s dependencies are checked > to make sure it’s > up to date. > > B depends on C (both in reality and in XCODE_DEPEND_HELPER.make), so C’s > dependencies are > checked. And if C’s dependencies aren’t up to date, or if C doesn’t exist at > all, C is > “built”, which in the context of XCODE_DEPEND_HELPER.make means that it’s > deleted, since > the action for C is “rm -f C”. > > As a consequence, building A seems to result in the deletion of C; and if > there are many > targets like A (targets that are depended on by things that also depend on > C), C can > be deleted many times. > > And, since there’s no dependency relationship between A and C, there’s > nothing preventing > A’s post-build step from running at the same time C is being built, which > produces (I think) > the errors we’re seeing. > > Does this analysis seem correct, or am I missing something about how > XCODE_DEPEND_HELPER.make > is supposed to work? > > Assuming I’m on the right track, what’s the right path to resolve the issue? > The dependency > structure referenced above seems to be valid, at least superficially, but > it’s giving Xcode fits. > We’re in the process of massaging the generated CMake into shape manually, > but I want to > make sure we’re headed in the right direction. > > Thanks in advance for any hints or guidance you can provide. > -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. 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