On Thu, 26 Nov 2020 19:32:28 GMT, John Neffenger <github.com+1413266+jgn...@openjdk.org> wrote:
>> I don't see any harm in this PR, but I wonder which toolchains are still not >> having `RTLD_NEXT` without specifying GNU_SOURCE. Does it also work if you >> specify `-D__USE_GNU` to the compiler? > >> I don't see any harm in this PR, but I wonder which toolchains are still not >> having `RTLD_NEXT` without specifying GNU_SOURCE. > > Thanks, Johan. I've been following the instructions in the [OpenJFX Wiki][1]. > I use the GCC cross-compiler installed by the repository's > [crosslibs-armv6hf.sh][2] script. Then I build for ARM using the repository's > [armv6hf.gradle][3] build file. > >> Does it also work if you specify `-D__USE_GNU` to the compiler? > > No, that prints the same error. The comments in the header file > `/usr/include/features.h` suggest that the macro `__USE_GNU` is for internal > use, while `_GNU_SOURCE` is defined by the user. I tried the user macro, and > it works! > > So below is an alternative fix in the ARM build file: > > diff --git a/buildSrc/armv6hf.gradle b/buildSrc/armv6hf.gradle > index 05e3e83551..bd56dcf86c 100644 > --- a/buildSrc/armv6hf.gradle > +++ b/buildSrc/armv6hf.gradle > @@ -140,7 +140,7 @@ def iioCFlags = [extraCFlags, > ].flatten() > def iioLFlags = [extraLFlags].flatten() > > -def es2EglfbCFlags = [extraCFlags, "-DIS_EGLFB", "-DLINUX"].flatten() > +def es2EglfbCFlags = [extraCFlags, "-DIS_EGLFB", "-DLINUX", > "-D_GNU_SOURCE"].flatten() > def es2EglfbLFlags = [extraLFlags].flatten() > def es2MonocleCFlags = [extraCFlags, "-DIS_EGLFB", "-DLINUX"].flatten() > def es2MonocleLFlags = [extraLFlags].flatten() > > It seems the [`_GNU_SOURCE` macro does a lot][4], so it's a question of > limiting its use to one C file or enabling it for the entire > `prism_es2_monocle` library. I'm fine with either solution. > > [1]: > https://wiki.openjdk.java.net/display/OpenJFX/Cross+Building+for+ARM+Hard+Float > [2]: > https://github.com/openjdk/jfx/blob/master/buildSrc/crosslibs/crosslibs-armv6hf.sh > [3]: https://github.com/openjdk/jfx/blob/master/buildSrc/armv6hf.gradle > [4]: https://stackoverflow.com/q/5582211 I think it is safer to use it as a flag for all monocle-es2 compilation then. It is also less intrusive as it doesn't require code changes, so it only affects specific builds. ------------- PR: https://git.openjdk.java.net/jfx/pull/350
