Examples with TreePathScanner com.sun.source.util.TreePathScanner used on opensource projects

Example 1 with TreePathScanner

use of com.sun.source.util.TreePathScanner in project bazel by bazelbuild.

the class JavaSource2CFGDOT method getMethodTreeAndCompilationUnit.

/**
     * @return The AST of a specific method in a specific class as well as the
     *         {@link CompilationUnitTree} in a specific file (or null they do
     *         not exist).
     */
public static Entry</*@Nullable*/
MethodTree, /*@Nullable*/
CompilationUnitTree> getMethodTreeAndCompilationUnit(String file, final String method, String clas) {
    final Holder<MethodTree> m = new Holder<>();
    final Holder<CompilationUnitTree> c = new Holder<>();
    BasicTypeProcessor typeProcessor = new BasicTypeProcessor() {

        @Override
        protected TreePathScanner<?, ?> createTreePathScanner(CompilationUnitTree root) {
            c.value = root;
            return new TreePathScanner<Void, Void>() {

                @Override
                public Void visitMethod(MethodTree node, Void p) {
                    ExecutableElement el = TreeUtils.elementFromDeclaration(node);
                    if (el.getSimpleName().contentEquals(method)) {
                        m.value = node;
                        // compilation).
                        throw new RuntimeException();
                    }
                    return null;
                }
            };
        }
    };
    Context context = new Context();
    JavaCompiler javac = new JavaCompiler(context);
    javac.attrParseOnly = true;
    JavacFileManager fileManager = (JavacFileManager) context.get(JavaFileManager.class);
    JavaFileObject l = fileManager.getJavaFileObjectsFromStrings(List.of(file)).iterator().next();
    PrintStream err = System.err;
    try {
        // redirect syserr to nothing (and prevent the compiler from issuing
        // warnings about our exception.
        System.setErr(new PrintStream(new OutputStream() {

            @Override
            public void write(int b) throws IOException {
            }
        }));
        javac.compile(List.of(l), List.of(clas), List.of(typeProcessor));
    } catch (Throwable e) {
    // ok
    } finally {
        System.setErr(err);
    }
    return new Entry<MethodTree, CompilationUnitTree>() {

        @Override
        public CompilationUnitTree setValue(CompilationUnitTree value) {
            return null;
        }

        @Override
        public CompilationUnitTree getValue() {
            return c.value;
        }

        @Override
        public MethodTree getKey() {
            return m.value;
        }
    };
}