in src/main/java/org/apache/maven/plugin/compiler/ForkedToolSources.java [410:428]
public void setLocationFromPaths(Location location, Collection<? extends Path> paths) {
PathType type = JavaPathType.valueOf(location).orElse(null);
if (type == null) {
if (location == StandardLocation.SOURCE_OUTPUT) {
type = OtherPathType.GENERATED_SOURCES;
} else if (location == StandardLocation.SOURCE_PATH) {
type = OtherPathType.SOURCES;
} else if (location == StandardLocation.CLASS_OUTPUT) {
type = OtherPathType.OUTPUT;
} else {
throw new IllegalArgumentException("Unsupported location: " + location);
}
}
if (paths == null || paths.isEmpty()) {
locations.remove(type);
} else {
locations.put(type, paths);
}
}