Force CMake in verbose mode via Gradle and the Android NDK
As an ugly workaround I've replaced ninja with my own executable that passes all the commands to the real ninja executable appending "-v"
Disclaimer: the following description applies to the version of Android Gradle Plugin (AGP) that was the latest at the time I updated this Answer (aug '21). If you are curious, have a look at the history of edits.
As @artyomd has noticed, for AGP 4.2.0 and higher, you can set android.native.buildOutput
gradle property to verbose
to force cmake logging.
In Android Studio, gradle creates directory .cxx
under the module root, for each module that has NDK integration, via CMake or ndk-build.
For CMake, the gradle plugin is quite verbose. For each build variant it creates separate subdirectory, e.g. .cxx/cmake/debug/x86
or .cxx/cmake/release/armeabi-v7a
, etc.
Each directory contains some useful files: cmake_build_command.txt describes the actual parameters passed to CMake; android_gradle_build.json shows what parameters the gradle plugin derived for your binaries; from build.ninja you can deduce the how these parameters were applied for each compilation or linkage step.
For ndk-build
, the android_gradle_build.json
file is also quite useful. ndkBuild_build_command.txt
lists all parameters passed to ndk-build command, and ndkBuild_build_output.txt
is the unabridged output of that command. You can easily add V=1
to the arguments, e.g.
externalNativeBuild {
ndkBuild {
cppFlags "-std=c++11"
arguments "APP_STL=c++_static", "APP_OPTIM=release", "NDK_DEBUG=0", "V=1"
abiFilters "armeabi-v7a"
}
}
For CMake
, the relevant argument is "-DCMAKE_VERBOSE_MAKEFILE=ON"
(see explanation
and alternatives):
externalNativeBuild {
cmake {
cppFlags "-std=c++11"
arguments "-DCMAKE_VERBOSE_MAKEFILE=ON"
abiFilters "armeabi-v7a"
}
}
But, as @user7860670 has observed, the recent versions of AGP ignore this flag.
Without CMAKE_VERBOSE_MAKEFILE
, the Gradle Console displays:
:app:externalNativeBuildDebug
Build native-lib armeabi-v7a
[1/2] Building CXX object CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o
[2/2] Linking CXX shared library ../../../../build/intermediates/cmake/debug/obj/armeabi-v7a/libnative-lib.so
With "-DCMAKE_VERBOSE_MAKEFILE:BOOL=ON"
, I used to get tons of output:
:app:externalNativeBuildDebug
Build native-lib armeabi-v7a
[1/2] /Users/alex/Library/Android/sdk/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang++ --target=armv5te-none-linux-androideabi --gcc-toolchain=/Users/alex/Library/Android/sdk/ndk-bundle/toolchains/arm-linux-androideabi-4.9/prebuilt/darwin-x86_64 --sysroot=/Users/alex/Library/Android/sdk/ndk-bundle/platforms/android-14/arch-arm -Dnative_lib_EXPORTS -isystem /Users/alex/Library/Android/sdk/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include -isystem /Users/alex/Library/Android/sdk/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/libs/armeabi-v7a/include -isystem /Users/alex/Library/Android/sdk/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/backward -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -march=armv5te -mtune=xscale -msoft-float -fno-integrated-as -mthumb -Wa,--noexecstack -Wformat -Werror=format-security -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -march=armv5te -mtune=xscale -msoft-float -fno-integrated-as -mthumb -Wa,--noexecstack -Wformat -Werror=format-security -O0 -fno-limit-debug-info -O0 -fno-limit-debug-info -fPIC -MD -MT CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o -MF CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o.d -o CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o -c /Users/alex/test/egl/app/src/main/cpp/native-lib.cpp
[2/2] : && /Users/alex/Library/Android/sdk/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang++ --target=armv5te-none-linux-androideabi --gcc-toolchain=/Users/alex/Library/Android/sdk/ndk-bundle/toolchains/arm-linux-androideabi-4.9/prebuilt/darwin-x86_64 --sysroot=/Users/alex/Library/Android/sdk/ndk-bundle/platforms/android-14/arch-arm -fPIC -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -march=armv5te -mtune=xscale -msoft-float -fno-integrated-as -mthumb -Wa,--noexecstack -Wformat -Werror=format-security -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -march=armv5te -mtune=xscale -msoft-float -fno-integrated-as -mthumb -Wa,--noexecstack -Wformat -Werror=format-security -O0 -fno-limit-debug-info -O0 -fno-limit-debug-info -Wl,--build-id -Wl,--warn-shared-textrel -Wl,--fatal-warnings -Wl,--no-undefined -Wl,-z,noexecstack -Qunused-arguments -Wl,-z,relro -Wl,-z,now -Wl,--build-id -Wl,--warn-shared-textrel -Wl,--fatal-warnings -Wl,--no-undefined -Wl,-z,noexecstack -Qunused-arguments -Wl,-z,relro -Wl,-z,now -shared -Wl,-soname,libnative-lib.so -o ../../../../build/intermediates/cmake/debug/obj/armeabi-v7a/libnative-lib.so CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o -llog -lEGL -lGLESv2 -lm "/Users/alex/Library/Android/sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a/libc++_static.a" "-latomic" && :
Not anymore. As far as I know, this information is filtered by Gradle Plugin and is completely lost. I can recover it only manually: run the command
/Users/alex/Library/Android/sdk/cmake/3.10.2.4988404/bin/cmake --build app/.cxx/cmake/debug/armeabi-v7a
You can use the Terminal window (Alt-F12) of Android Studio. This will invoke ninja with -v
flag when -DCMAKE_VERBOSE_MAKEFILE=ON
was used to sync C++ with Gradle.
Note that the expected file .cxx/cmake/debug/armeabi-v7a/cmake_build_output.txt
does not contain interesting information (unless you have problems with CMake configuration per se).
P.S. with this 3.6.0 Gradle Plugin, if you have a compilation error, then the whole command line for compiler is shown in Build Output window, no matter whether you set CMAKE_VERBOSE_MAKEFILE
or not. Actually, twice: once, in black on white (I don't use the dark theme), second time, in brown on white, after
FAILURE: Build failed with an exception.
* What went wrong: