gradle source code analysis

• 1. Starting Gradle

• 1.1 Overall Implementation Diagram

• Basically, the construction process is divided into five steps. Let's look at these five processes separately.

• 二、loadSettings

• 2.1 Overall realization diagram

• 2.2 Specific analysis

• 2.2.1 Call BuildListener.buildStarted() callback interface

• 2.2.2 Execute the init script

• 2.2.3 Find settings.gradle location

• 2.2.4 Compile the content under the buildSrc folder, buildSrc can be regarded as a plug-in similar function

• 2.2.5 Analysis gradle.properites

• 2.2.6 Analysis settings.gradle

• 2.2.7 Create project and subproject

• 3. configureBuild

• 3.1 Overall realization diagram

• 3.2 Specific analysis

• 3.2.1 Configure the main link of the main project and its sub-projects

• 3.2.2 Callback BuildListener.beforeEvaluate interface

• 3.2.3 Set default tasks and plugins

• 3.2.4 Compile the script and execute it

• 3.2.5 Callback BuildListener.afterEvaluate

• 3.2.6 Callback BuildListener.projectsEvaluated

• 四、constructTaskGraph

• 4.1 Overall realization diagram

• 4.2 Specific analysis

• 4.2.1 Processing tasks that need to be excluded

• 4.2.2 Add default task

• 4.2.3 Calculate task dependency graph

• 4.2.4 Generate task graph

• Five, runTasks

• 5.1 Overall realization diagram

• 5.2 Specific analysis

• 5.2.1 Dealing with dry run

• 5.2.2 Create threads and execute tasks

• 5.2.3 Task execution pre-processing

• 5.2.4 task execution

• 六、finishBuild

• 6.1 Overall realization diagram

• 6.2 Specific analysis

• 7. How to compile and execute the gradle script

• 7.1 Compile the script

• 7.2 Call script run method

• Eight, plug-in call process

• Nine. Summary

1. Starting Gradle

gradle source official website https://android.googlesource.com/platform/tools/base/+/gradle_2.3.0/build-system/

1.1 Overall Implementation Diagram

The source code corresponding to the above figure is the Stage in DefaultGradleLauncher

1.2 Specific analysis

When we execute a build task, we always execute commands like ./gradlew assembleDebug, where the gradlew script is the entry point of the entire gradle build. Let's start from here.

The previous code is basically to judge the environment and set variables, just look at the last line:

exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"

The final command executed is basically as follows:

exec $JAVA_HOME/bin/java -classpath $APP_HOME/gradle/wrapper/gradle-wrapper.jar org.gradle.wrapper.GradleWrapperMain

Here we know that the entrance of the whole gradle is GradleWrapperMain. Basically, we can see that the org.gradle.wrapper.GradleWrapperMain in gradle/wrapper/gradle-wrapper.jar is executed, so we know, gradle