Incorrect semantics of JavacCompiler.isPreJavaXX

[kwin]

According to the javadoc of

plexus-compiler/plexus-compilers/plexus-compiler-javac/src/main/java/org/codehaus/plexus/compiler/javac/JavacCompiler.java

Line 410 in c5edddc

private static boolean isPreJava16(CompilerConfiguration config) {

and

plexus-compiler/plexus-compilers/plexus-compiler-javac/src/main/java/org/codehaus/plexus/compiler/javac/JavacCompiler.java

Line 393 in c5edddc

private static boolean isPreJava14(CompilerConfiguration config) {

the methods isPreJavaXX are supposed to

return true if the compiler configuration represents a Java XX compiler or later, false otherwise

The logic within those methods evaluates partially also the parameter source (

plexus-compiler/plexus-compilers/plexus-compiler-javac/src/main/java/org/codehaus/plexus/compiler/javac/JavacCompiler.java

Line 418 in c5edddc

v = config.getSourceVersion();

) or release (

plexus-compiler/plexus-compilers/plexus-compiler-javac/src/main/java/org/codehaus/plexus/compiler/javac/JavacCompiler.java

Line 435 in c5edddc

String v = config.getReleaseVersion();

) which are completely orthogonal to the javac version being used. They only determine the bytecode version being generated but have nothing to do with the version of the compiler itself.

However I am not sure when CompilerConfiguration.getCompilerVersion() is reliably set at all. IMHO there should be some logic separate for in-process and forked compiling which determines the real javac version (either from system property java.version for in-process compilation or the parsed output of javac -version)

[kwin]

Actually the CompilerConfiguration.getCompilerVersion only exposes what is set via https://maven.apache.org/plugins/maven-compiler-plugin/compile-mojo.html#compilerVersion so this does not necessarily reflect the actual javac version either. The deprecation of that parameter is tracked in https://issues.apache.org/jira/browse/MCOMPILER-573.