desruisseaux commented on PR #160: URL: https://github.com/apache/maven-compiler-plugin/pull/160#issuecomment-2070967076
While incremental builds is important, my reading of the source code inherited from Maven 3 suggests that in its current state, incremental build has bugs causing the opposite effect than what the plugin wanted to achieve. We could try to fix the Maven 3 compiler plugin, but I do not know if it is worth the effort given that the plugin is getting a significant rewrite for Maven 4. The current `useIncrementalCompilation` parameter is a boolean flag which is actually mixing at least two aspects: whether to check if a dependency changed, and how to detect which source files changed. I suggest to deprecate that parameter and replace it with a new `incrementalCompilation` parameter (same name but without `use` prefix). The value of that parameter would be a comma-separated list of the following: * `dependencies`: check whether a dependency changed. * `sources`: check whether a source file has been updated, or whether source files were added or removed. * `classes`: check whether a source file is more recent than its `.class` file. * `modules` (new): don't try to do incremental build in Maven, but delegate that task to `javac` instead. This is possible only with modular projects. It uses the `--module` compiler option, which is an alternative to enumerating all source files on the command-line. Equivalences with the current parameter: * `useIncrementalCompilation = true` is equivalent to `incrementalCompilation = dependencies,sources` (except maybe for the cases of newly added source files). * `useIncrementalCompilation = false` is equivalent to `incrementalCompilation = classes`. For an initial version of the Maven 4 compiler plugin, detection of changes would be based only on file timestamps. This is the same strategy than the current plugin. This approach would be unable to detect that a class needs to be recompiled because it depends on another class which has been changed. However, the current plugin cannot detect such cases neither, so we don't lost anything. If we support that feature in the future, it would be one new value in the above-cited list of comma-separated values. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
