Undefined reference Error in Android Embedded

[Jian Guo]

I tried to import v8 7.6.90 as a static library in my Android NDK project, but it fails at the link process. 

Here is my args.gn config for v8 build:

android_unstripped_runtime_outputs = true

v8_use_external_startup_data = false

is_debug = false

symbol_level = 1

target_cpu = "arm"

target_os = "android"

use_goma = false

v8_enable_i18n_support = false

v8_static_library = true

is_component_build = false

v8_monolithic = true

v8_android_log_stdout = true

It did compile and gave me a libv8_monolith.a after compiling, I started to set up my Android project then.

CMakeLists.txt:

cmake_minimum_required(VERSION 3.4.1)

add_library(v8 STATIC IMPORTED)

set_target_properties( v8 PROPERTIES IMPORTED_LOCATION ${CMAKE_SOURCE_DIR}/libs/${ANDROID_ABI}/libv8_monolith.a)

add_library( # Sets the name of the library.

        native-lib

        # Sets the library as a shared library.

        SHARED

        # Provides a relative path to your source file(s).

        ${CMAKE_SOURCE_DIR}/src/main/cpp/native-lib.cpp)

target_include_directories( native-lib PRIVATE ${CMAKE_SOURCE_DIR}/libs/include)

find_library( # Sets the name of the path variable.

        log-lib

        # Specifies the name of the NDK library that

        # you want CMake to locate.

        log)

target_link_libraries( # Specifies the target library.

        native-lib

        v8

        # Links the target library to the log library

        # included in the NDK.

        ${log-lib})

build.gradle:

externalNativeBuild {
    cmake {
        cppFlags "-std=c++0x"
    }
}
ndk {
    abiFilters "armeabi-v7a"
}

native-lib.cpp runs the same example in https://chromium.googlesource.com/v8/v8/+/master/samples/hello-world.cc

But ld always complains about the error:

error: undefined reference to 'v8::platform::NewDefaultPlatform(int, v8::platform::IdleTaskSupport, v8::platform::InProcessStackDumping, std::__ndk1::unique_ptr<v8::TracingController, std::__ndk1::default_delete<v8::TracingController> >)'

I tried to objdump my libv8_monolith.a:

objdump -D app/libs/armeabi-v7a/libv8_monolith.a | grep NewDefault

Disassembly of section .text._ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE:

_ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE:

       4:       81 b0 01 2b     blhs    #442884 <_ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE+0x6C210>

Disassembly of section .rel.text._ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE:

.rel.text._ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE:

Disassembly of section .ARM.exidx.text._ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE:

.ARM.exidx.text._ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE:

Disassembly of section .rel.ARM.exidx.text._ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE:

.rel.ARM.exidx.text._ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE:

Disassembly of section .text._ZN2v811ArrayBuffer9Allocator19NewDefaultAllocatorEv:

_ZN2v811ArrayBuffer9Allocator19NewDefaultAllocatorEv:

Disassembly of section .rel.text._ZN2v811ArrayBuffer9Allocator19NewDefaultAllocatorEv:

.rel.text._ZN2v811ArrayBuffer9Allocator19NewDefaultAllocatorEv:

Disassembly of section .ARM.exidx.text._ZN2v811ArrayBuffer9Allocator19NewDefaultAllocatorEv:

.ARM.exidx.text._ZN2v811ArrayBuffer9Allocator19NewDefaultAllocatorEv:

Disassembly of section .rel.ARM.exidx.text._ZN2v811ArrayBuffer9Allocator19NewDefaultAllocatorEv:

.rel.ARM.exidx.text._ZN2v811ArrayBuffer9Allocator19NewDefaultAllocatorEv:

_ZN2v88platform18NewDefaultPlatformEiNS0_15IdleTaskSupportENS0_21InProcessStackDumpingENSt3__110unique_ptrINS_17TracingControllerENS3_14default_deleteIS5_EEEE 

should be 

v8::platform::NewDefaultPlatform(int, v8::platform::IdleTaskSupport, v8::platform::InProcessStackDumping, std::__1::unique_ptr<v8::TracingController, std::__1::default_delete<v8::TracingController> >)

However, in the error message, the ld tries to find  std::__ndk1::unique_ptr<v8::TracingController, std::__ndk1::default_delete<v8::TracingController> >)'

I think they have a different namespace, but how do I solve this problem? I found a similar issue here https://groups.google.com/forum/#!topic/v8-users/Jb1VSouy2Z0, but the solution didn't work for me.

Any ideas? Thanks for your help.

P.S:

NDK version in my Android Project: 19.1.53

[Jian Guo]

After searching through the codebase, I found something interesting.

In thrid_party/android_ndk/cxx-stl/llvm-libc++/include/__config:

#define _LIBCPP_NAMESPACE _LIBCPP_CONCAT(__ndk,_LIBCPP_ABI_VERSION)
#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std {inline namespace _LIBCPP_NAMESPACE {

#define _LIBCPP_END_NAMESPACE_STD  } }

#define _VSTD std::_LIBCPP_NAMESPACE

namespace std {

  inline namespace _LIBCPP_NAMESPACE {

  }

}

But in buildtools/third_party/libc++/trunk/include/__config:

#ifndef _LIBCPP_ABI_NAMESPACE

# define _LIBCPP_ABI_NAMESPACE _LIBCPP_CONCAT(__,_LIBCPP_ABI_VERSION)

#endif

#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std { inline namespace _LIBCPP_ABI_NAMESPACE {

#define _LIBCPP_END_NAMESPACE_STD  } }

#define _VSTD std::_LIBCPP_ABI_NAMESPACE

_LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_END_NAMESPACE_STD

I think they are different from each other, as the first one should be "std::__ndk1", and the second one should be "std::__1".