RFR: 8198317: Enhance JavacTool.getTask for flexibility [v2]

[Guoxiong Li]

On Fri, 25 Dec 2020 20:51:43 GMT, Jonathan Gibbons <jjg at openjdk.org> wrote:

>> Guoxiong Li has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Add a test case.
>
> As a general rule, all changes should have an accompanying regression test, unless there is a good reason why not.   The set of good reasons has a corresponding list of JBS labels, shown here: http://openjdk.java.net/guide/#noreg
> 
> The closest match here would be `noreg-trivial` but I don't think it is close enough to claim that. In other words, I think this change needs a corresponding new test.  It is also not uncommon for small changes like this to more effort to write the test than fixing the underlying issue.
> 
> --
> 
> * *Unit test*: insurance against having to writing a regression test later on
> * *Regression test*: the penalty for not writing a unit test in the first place

I submit a test case. But I don't satisfy with it, because it can't meet all the situations.
I try to use the reflect api locally to write a better test. Please see the code below. The code can't be compiled.

    @Test
    public void testLogSettingInJavacTool() throws Exception {
        Class<?> pwClass = Class.forName("java.io.PrintWriter");
        Field psOutField = pwClass.getDeclaredField("psOut");
        psOutField.setAccessible(true);
        Field outField = pwClass.getDeclaredField("out");
        outField.setAccessible(true);

        // Situation: out is null and the value is not set in the context.
        JavacTaskImpl task1 = (JavacTaskImpl) ToolProvider
                .getSystemJavaCompiler()
                .getTask(null, null, null, null, null, null);
        PrintWriter writer1 = task1.getContext().get(Log.errKey);
        PrintStream psOut1 = (PrintStream) psOutField.get(writer1);
        if (!System.err.equals(psOut1)) {
            throw new Error("The PrintWriter is set uncorrectly.");
        }

        // Situation: out is not null and out is a PrintWriter.
        PrintWriter expectedPW = new PrintWriter(System.out);
        JavacTaskImpl task2 = (JavacTaskImpl) ToolProvider
                .getSystemJavaCompiler()
                .getTask(expectedPW, null, null, null, null, null);
        PrintWriter writer2 = task2.getContext().get(Log.errKey);
        PrintStream psOut2 = (PrintStream) psOutField.get(writer2);
        if (!System.out.equals(psOut2) || expectedPW.equals(writer2)) {
            throw new Error("The PrintWriter is set uncorrectly.");
        }

        // Situation: out is not null and out is not a PrintWriter.
        OutputStreamWriter expectedOSW = new OutputStreamWriter(System.out);
        JavacTaskImpl task3 = (JavacTaskImpl) ToolProvider
                .getSystemJavaCompiler()
                .getTask(expectedOSW, null, null, null, null, null);
        PrintWriter writer3 = task3.getContext().get(Log.errKey);
        Writer out3 = (Writer) outField.get(writer3);
        if (!(out3 instanceof OutputStreamWriter) || !expectedOSW.equals(out3)) {
            throw new Error("The PrintWriter is set uncorrectly.");
        }
    }

The error information is shown below.

STDERR:
test: testLogSettingInJavacTool
Exception running test testLogSettingInJavacTool: java.lang.reflect.InaccessibleObjectException: Unable to make field private java.io.PrintStream java.io.PrintWriter.psOut accessible: module java.base does not "opens java.io" to unnamed module @2fd66ad3
java.lang.reflect.InaccessibleObjectException: Unable to make field private java.io.PrintStream java.io.PrintWriter.psOut accessible: module java.base does not "opens java.io" to unnamed module @2fd66ad3
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:357)
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
	at java.base/java.lang.reflect.Field.checkCanSetAccessible(Field.java:177)
	at java.base/java.lang.reflect.Field.setAccessible(Field.java:171)
	at T8198317.testLogSettingInJavacTool(T8198317.java:63)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:567)
	at toolbox.TestRunner.runTests(TestRunner.java:89)
	at toolbox.TestRunner.runTests(TestRunner.java:73)
	at T8198317.main(T8198317.java:56)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:567)
	at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:298)
	at java.base/java.lang.Thread.run(Thread.java:831)

A better test case would be appreciated.

-------------

PR: https://git.openjdk.java.net/jdk/pull/1896