I'm facing the same issue. I built v8 for Android, and when linking `libv8_monolith.a` in my app using NDK, there are link errors. The app and the other third-party libs use the NDK libc++ expecting the `std::__ndk1` namespace, but v8 is expecting `std::__1`.
I couldn't find a way to tell the v8 build system to use the libc++ from the NDK. Is there really no way to use the default libc++ from NDK when compiling v8? In case the only solution is to use the libc++ version imposed by v8 everywhere (like Darin Dimitrov did), how is it done? I'm couldn't find an appropriate lib to link in `buildtools/third_party/libc++`. I could find some `libc++_static.a` in the v8 source tree, but they are in `third_party/android_ndk/` and they use `std::__ndk1` (see [1] and [2]). Any advice of how to correctly use v8 with NDK is appreciated. The official documentation helps to get v8 compiled standalone (https://v8.dev/docs/cross-compile-arm), but the difficult part starts when trying linking it with other libs and code. I tried with both 7.3-lkgr and 8.3-lkgr v8 versions. -------------------------- [1]: Searching for `libc++_static.a` in the v8 source tree find . -name libc++_static.a ./third_party/android_ndk/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/i686-linux-android/libc++_static.a ./third_party/android_ndk/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/aarch64-linux-android/libc++_static.a ./third_party/android_ndk/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/x86_64-linux-android/libc++_static.a ./third_party/android_ndk/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/arm-linux-androideabi/libc++_static.a ./third_party/android_ndk/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a/libc++_static.a ./third_party/android_ndk/sources/cxx-stl/llvm-libc++/libs/arm64-v8a/libc++_static.a ./third_party/android_ndk/sources/cxx-stl/llvm-libc++/libs/x86_64/libc++_static.a ./third_party/android_ndk/sources/cxx-stl/llvm-libc++/libs/x86/libc++_static.a [2]: checking the demangled names used in the static library ~/Android/Sdk/ndk/21.3.6528147/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/bin/aarch64-linux-android-nm --demangle third_party/android_ndk/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/i686-linux-android/libc++_static.a | grep string 00000000 W std::__ndk1::__basic_string_common<true>::__throw_length_error() const .... On Wed, Feb 20, 2019, at 10:41 PM, Darin Dimitrov wrote: > Turns out that V8 is building against a custom STL passing the > _LIBCPP_ABI_UNSTABLE flag. So in order to build my final executable I had to > use this same STL instead of the default libc++_static.a library provided by > the NDK. > > On Wednesday, February 13, 2019 at 9:24:34 AM UTC+2, Darin Dimitrov wrote: >> Tom, thanks for the reply. The DefaultPlatform method was just an example. >> Looking at the public API in v8.h >> <https://github.com/v8/v8/blob/master/include/v8.h> there are quite a lot of >> references to C++ objects from the standard library and I am getting tons of >> those similar linker errors. That's what made me think that I must be doing >> something wrong. >> >> I managed to successfully compile and link if I manually modify >> _LIBCPP_ABI_NAMESPACE in the "third_party/libc++/trunk/include/__config" >> include file. But I feel that it should somehow be possible to specify the >> libc++ location when building v8 so that it uses the one from the NDK. >> >> On Tuesday, February 12, 2019 at 10:15:04 PM UTC+2, Tom Anderson wrote: >>> Usually C++ objects should not be passed over library boundaries. In this >>> case though, the issue could be fixed by adding a wrapper for >>> v8::platform::DefaultPlatform::DefaultPlatform() that takes a C-style >>> pointer instead of a unique_ptr. >>> >>> I'm also not sure if v8_libplatform is meant to be redistributed in this >>> way, though the V8 team can say for sure. >>> >>> On Tuesday, February 12, 2019 at 8:05:19 AM UTC-8, Darin Dimitrov wrote: >>>> Further narrowing this down. >>>> >>>> In V8 *7.2*, libc++ is taken from the NDK: >>>> >>>> -isystem../../third_party/android_ndk/sources/cxx-stl/llvm-libc++/include >>>> -isystem../../third_party/android_ndk/sources/cxx-stl/llvm-libc++abi/include >>>> >>>> whereas in V8 *7.3*, a different libc++ is used: >>>> >>>> -isystem../../buildtools/third_party/libc++/trunk/include >>>> -isystem../../buildtools/third_party/libc++abi/trunk/include >>>> >>>> And the difference between the two versions is that the one from the NDK >>>> defines the following std namespace override: >>>> >>>> #ifndef _LIBCPP_ABI_NAMESPACE >>>> # define _LIBCPP_ABI_NAMESPACE _LIBCPP_CONCAT(__ndk,_LIBCPP_ABI_VERSION) >>>> #endif >>>> >>>> while the custom one uses this: >>>> >>>> #ifndef _LIBCPP_ABI_NAMESPACE >>>> # define _LIBCPP_ABI_NAMESPACE _LIBCPP_CONCAT(__,_LIBCPP_ABI_VERSION) >>>> #endif >>>> >>>> So the question is, what would be the proper gn arguments to link against >>>> libc++ from the NDK? >>>> >>>> I have tried setting use_custom_libcxx=false but in this case no -isystem >>>> is specified and the build fails as it cannot find some common includes >>>> such as <memory> and <functional>. >>>> >>>> On Monday, February 11, 2019 at 6:09:49 PM UTC+2, Darin Dimitrov wrote: >>>>> I was able to bisect the issue to the following commit in which the V8 >>>>> DEPS were updated: >>>>> https://chromium.googlesource.com/v8/v8/+/843535b893968a89f98b295cd7b1b265ca2927c1 > > -- > -- > v8-users mailing list > v8-users@googlegroups.com > http://groups.google.com/group/v8-users > --- > You received this message because you are subscribed to the Google Groups > "v8-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. 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