CODEWITHSUNDEEP
android-ndkgradle
Alex Flint
Alex Flint

Reputation: 6686

Using clang from NDK gradle build system

Using the old Makefile-based Android build system it is possible to using clang to compile sources by adding

NDK_TOOLCHAIN_VERSION=clang

Is there some way to achieve the same thing using the new gradle build system?

Upvotes: 2

Views: 1817

Answers (2)

Cameron Lowell Palmer
Cameron Lowell Palmer

Reputation: 22225

Newer NDK revisions default to Clang. However, you can explicitly request a toolchain using the -DANDROID_TOOLCHAIN switch.

As of the Android Gradle Plugin 2.2.0 things have become much better. You can also adopt cmake. You should look over the new documentation.

android {
  ...
  defaultConfig {
    ...
    // This block is different from the one you use to link Gradle
    // to your CMake or ndk-build script.
    externalNativeBuild {

      // For ndk-build, instead use ndkBuild {}
      cmake {

        // Passes optional arguments to CMake.
        arguments "-DANDROID_TOOLCHAIN=clang"

        // Sets optional flags for the C compiler.
        cFlags "-D_EXAMPLE_C_FLAG1", "-D_EXAMPLE_C_FLAG2"

        // Sets a flag to enable format macro constants for the C++ compiler.
        cppFlags "-D__STDC_FORMAT_MACROS"
      }
    }
  }

  buildTypes {...}

  productFlavors {
    ...
    demo {
      ...
      externalNativeBuild {
        cmake {
          ...
          // Specifies which native libraries to build and package for this
          // product flavor. If you don't configure this property, Gradle
          // builds and packages all shared object libraries that you define
          // in your CMake or ndk-build project.
          targets "native-lib-demo"
        }
      }
    }

    paid {
      ...
      externalNativeBuild {
        cmake {
          ...
          targets "native-lib-paid"
        }
      }
    }
  }

  // Use this block to link Gradle to your CMake or ndk-build script.
  externalNativeBuild {
    cmake {...}
    // or ndkBuild {...}
  }
}

Upvotes: 0

ph0b
ph0b

Reputation: 14463

It's not directly possible for now, but you can still use the regular Makefiles from gradle:

import org.apache.tools.ant.taskdefs.condition.Os

apply plugin: 'android'

android {
    ...
    sourceSets.main {
        jniLibs.srcDir 'src/main/libs' //set jniLibs directory to ./libs
        jni.srcDirs = [] //disable automatic ndk-build call
    }

    // call regular ndk-build(.cmd) script from main src directory
    task ndkBuild(type: Exec) {
        if (Os.isFamily(Os.FAMILY_WINDOWS)) {
            commandLine 'ndk-build.cmd', '-C', file('src/main').absolutePath
        } else {
            commandLine 'ndk-build', '-C', file('src/main').absolutePath
        }
    }

    tasks.withType(JavaCompile) {
        compileTask -> compileTask.dependsOn ndkBuild
    }
}

Upvotes: 1

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