GCC is no longer supported - C++17 - Android Studio

Question

I need to use C++17 compliant source files in my Android project. I added my .cpp files to the src/main/cpp folder.

After the build, this error appears:

Build command failed.
Error while executing process 
/Users/khasan/Library/Android/sdk/cmake/3.6.4111459/bin/cmake with 
arguments {-H/Users/khasan/Projects/myapplication/app -B/Users/khasan/Projects/myapplication/app/.externalNativeBuild/cmake/debug/ 
arm64-v8a -DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=android-21 -DCMAKE_LIBRARY_OUTPUT_DIRECTORY=/Users/khasan/Projects/myapplication/app/bu 
ild/intermediates/cmake/debug/obj/arm64-v8a -DCMAKE_BUILD_TYPE=Debug -DANDROID_NDK=/Users/khasan/Library/Android/sdk/ndk-bundle - 
DCMAKE_CXX_FLAGS=-std=c++17 -fexceptions -frtti - 
DCMAKE_TOOLCHAIN_FILE=/Users/khasan/Library/Android/sdk/ndk- 
bundle/build/cmake/android.toolchain.cmake -DCMAKE_MAKE_PROGRAM=/Users/khasan/Library/Android/sdk/cmake/3.6.4111459/bin 
/ninja -GAndroid Gradle - Ninja -DBUILD_TESTING=OFF -DANDROID_TOOLCHAIN=gcc}
-- Configuring incomplete, errors occurred!

CMake Error at /Users/khasan/Library/Android/sdk/ndk-bundle/build/cmake/android.toolchain.cmake:169 (message):
GCC is no longer supported.  See https://android.googlesource.com/platform/ndk/+/master/docs/ClangMigration .md.
Call Stack (most recent call first):
  /Users/khasan/Library/Android/sdk/cmake/3.6.4111459/share/cmake- 3.6/Modules/CMakeDetermineSystem.cmake:98 (include)
   CMakeLists.txt


CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage
CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage

My build.gradle:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "ganikhodjaev.test.myapplication"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

        externalNativeBuild {
            cmake {
                cppFlags "-std=c++17 -fexceptions -frtti"
                arguments '-DBUILD_TESTING=OFF', '-DANDROID_TOOLCHAIN=gcc'
            }
        }

        ndk {
            abiFilters 'x86', 'armeabi-v7a', 'x86_64', 'arm64-v8a'
        }
    }
    packagingOptions {
        doNotStrip '*/mips/*.so'
        doNotStrip '*/mips64/*.so'
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    externalNativeBuild {
        cmake {
            path file('CMakeLists.txt')

        }
    }

    dependencies {
         implementation fileTree(dir: 'libs', include: ['*.jar'])
         implementation 'com.android.support:appcompat-v7:28.0.0'
         implementation 'com.android.support.constraint:constraint-layout:1.1.3'
         testImplementation 'junit:junit:4.12'
         androidTestImplementation 'com.android.support.test:runner:1.0.2'
         androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    }
}

NDK version 19. Maybe I connect something wrong?

Answer 1

For Android NDK, llvm/Clang became the default toolchain since r13b and gcc was removed since r18b.

You need to remove '-DANDROID_TOOLCHAIN=gcc' and let the build system to select clang by default.

Also, cross check ndk revision history and --gcc-toolchain changes and clang migration from gcc.