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ExternalNativeCmakeOptions

@Incubating interface ExternalNativeCmakeOptions
com.android.build.api.dsl.ExternalNativeCmakeOptions

DSL object for per-variant CMake options, such as CMake arguments and compiler flags.

To learn more about including CMake builds to your Android Studio projects, read Add C and C++ Code to Your Project. You can also read more documentation about the Android CMake toolchain.

Summary

Public methods

abstract Unit
abiFilters(vararg abiFilters: String)

Specifies the Application Binary Interfaces (ABI) that Gradle should build outputs for.

abstract Unit
arguments(vararg arguments: String)

Specifies arguments for CMake.

abstract Unit
cFlags(vararg cFlags: String)

Specifies flags for the C compiler.

abstract Unit
cppFlags(vararg cppFlags: String)

Specifies flags for the C++ compiler.

abstract Unit
targets(vararg targets: String)

Specifies the library and executable targets from your CMake project that Gradle should build.

Properties

abstract MutableSet<String>

Specifies the Application Binary Interfaces (ABI) that Gradle should build outputs for.

abstract MutableList<String>

Specifies arguments for CMake.

abstract MutableList<String>

Specifies flags for the C compiler.

abstract MutableList<String>

Specifies flags for the C++ compiler.

abstract MutableSet<String>

Specifies the library and executable targets from your CMake project that Gradle should build.

Public methods

abiFilters

abstract fun abiFilters(vararg abiFilters: String): Unit

Specifies the Application Binary Interfaces (ABI) that Gradle should build outputs for. The ABIs that Gradle packages into your APK are determined by android.defaultConfig.ndk.abiFilter

In most cases, you need to specify ABIs using only android.defaultConfig.ndk.abiFilter, because it tells Gradle which ABIs to both build and package into your APK. However, if you want to control what Gradle should build, independently of what you want it to package into your APK, configure this property with the ABIs you want Gradle to build.

To further reduce the size of your APK, consider configuring multiple APKs based on ABI—instead of creating one large APK with all versions of your native libraries, Gradle creates a separate APK for each ABI you want to support and only packages the files each ABI needs.

By default, this property is null.

arguments

abstract fun arguments(vararg arguments: String): Unit

Specifies arguments for CMake.

The following sample enables NEON support and tells CMake to use the Clang compiler toolchain:

android {
    // Similar to other properties in the defaultConfig block, you can override
    // these properties for each product flavor you configure.
    defaultConfig {
        externalNativeBuild {
            cmake {
                // Passes optional arguments to CMake.
                arguments "-DANDROID_ARM_NEON=TRUE", "-DANDROID_TOOLCHAIN=clang"
            }
        }
    }
}

By default, this property is null. For a list of properties you can configure, see CMake Variables List.

cFlags

abstract fun cFlags(vararg cFlags: String): Unit

Specifies flags for the C compiler.

The following sample enables format macro constants:

android {
    // Similar to other properties in the defaultConfig block, you can override
    // these properties for each product flavor in your build configuration.
    defaultConfig {
        externalNativeBuild {
            cmake {
                // Sets an optional flag for the C compiler.
                cFlags "-D__STDC_FORMAT_MACROS"
            }
        }
    }
}

By default, this property is null.

cppFlags

abstract fun cppFlags(vararg cppFlags: String): Unit

Specifies flags for the C++ compiler.

The following sample enables RTTI (RunTime Type Information) support and C++ exceptions:

android {
    // Similar to other properties in the defaultConfig block, you can override
    // these properties for each product flavor in your build configuration.
    defaultConfig {
        externalNativeBuild {
            cmake {
                // Sets optional flags for the C++ compiler.
                cppFlags "-fexceptions", "-frtti"
            }
        }
    }
}

By default, this property is null.

targets

abstract fun targets(vararg targets: String): Unit

Specifies the library and executable targets from your CMake project that Gradle should build.

For example, if your CMake project defines multiple libraries and executables, you can tell Gradle to build only a subset of those outputs as follows:

android {
    // Similar to other properties in the defaultConfig block, you can override
    // these properties for each product flavor in your build configuration.
    defaultConfig {
        externalNativeBuild {
            cmake {
                // The following tells Gradle to build only the "libexample-one.so" and
                // "my-executible-two" targets from the linked CMake project. If you don't
                // configure this property, Gradle builds all executables and shared object
                // libraries that you define in your CMake project. However, Gradle packages
                // only shared libraries into your APK.
                targets "libexample-one",
                        // You need to specify this executable and its sources in your
                        // CMakeLists.txt using the add_executable() CMake command. However,
                        // building executables from your native sources is optional, and
                        // building native libraries to package into your APK satisfies most
                        // project requirements.
                        "my-executible-demo"
            }
        }
    }
}

If you don't configure this property, Gradle builds all executables and shared object libraries that you define in your CMake project. However, by default, Gradle packages only the shared libraries in your APK.

Properties

abiFilters

abstract val abiFilters: MutableSet<String>

Specifies the Application Binary Interfaces (ABI) that Gradle should build outputs for. The ABIs that Gradle packages into your APK are determined by android.defaultConfig.ndk.abiFilter

In most cases, you need to specify ABIs using only android.defaultConfig.ndk.abiFilter, because it tells Gradle which ABIs to both build and package into your APK. However, if you want to control what Gradle should build, independently of what you want it to package into your APK, configure this property with the ABIs you want Gradle to build.

To further reduce the size of your APK, consider configuring multiple APKs based on ABI—instead of creating one large APK with all versions of your native libraries, Gradle creates a separate APK for each ABI you want to support and only packages the files each ABI needs.

By default, this property is null.

arguments

abstract val arguments: MutableList<String>

Specifies arguments for CMake.

The following sample enables NEON support and tells CMake to use the Clang compiler toolchain:

android {
    // Similar to other properties in the defaultConfig block, you can override
    // these properties for each product flavor you configure.
    defaultConfig {
        externalNativeBuild {
            cmake {
                // Passes optional arguments to CMake.
                arguments "-DANDROID_ARM_NEON=TRUE", "-DANDROID_TOOLCHAIN=clang"
            }
        }
    }
}

By default, this property is null. For a list of properties you can configure, see CMake Variables List.

cFlags

abstract val cFlags: MutableList<String>

Specifies flags for the C compiler.

The following sample enables format macro constants:

android {
    // Similar to other properties in the defaultConfig block, you can override
    // these properties for each product flavor in your build configuration.
    defaultConfig {
        externalNativeBuild {
            cmake {
                // Sets an optional flag for the C compiler.
                cFlags "-D__STDC_FORMAT_MACROS"
            }
        }
    }
}

By default, this property is null.

cppFlags

abstract val cppFlags: MutableList<String>

Specifies flags for the C++ compiler.

The following sample enables RTTI (RunTime Type Information) support and C++ exceptions:

android {
    // Similar to other properties in the defaultConfig block, you can override
    // these properties for each product flavor in your build configuration.
    defaultConfig {
        externalNativeBuild {
            cmake {
                // Sets optional flags for the C++ compiler.
                cppFlags "-fexceptions", "-frtti"
            }
        }
    }
}

By default, this property is null.

targets

abstract val targets: MutableSet<String>

Specifies the library and executable targets from your CMake project that Gradle should build.

For example, if your CMake project defines multiple libraries and executables, you can tell Gradle to build only a subset of those outputs as follows:

android {
    // Similar to other properties in the defaultConfig block, you can override
    // these properties for each product flavor in your build configuration.
    defaultConfig {
        externalNativeBuild {
            cmake {
                // The following tells Gradle to build only the "libexample-one.so" and
                // "my-executible-two" targets from the linked CMake project. If you don't
                // configure this property, Gradle builds all executables and shared object
                // libraries that you define in your CMake project. However, Gradle packages
                // only shared libraries into your APK.
                targets "libexample-one",
                        // You need to specify this executable and its sources in your
                        // CMakeLists.txt using the add_executable() CMake command. However,
                        // building executables from your native sources is optional, and
                        // building native libraries to package into your APK satisfies most
                        // project requirements.
                        "my-executible-demo"
            }
        }
    }
}

If you don't configure this property, Gradle builds all executables and shared object libraries that you define in your CMake project. However, by default, Gradle packages only the shared libraries in your APK.