GNU bug report logs - #75440
dejagnu does not like java.io.Console of OpenJDK >= 22

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Chris Nospam <chris21k <at> gmx.de>
To: bug-dejagnu <at> gnu.org
Subject: dejagnu does not like java.io.Console of OpenJDK >= 22
Date: Wed, 8 Jan 2025 16:44:55 +0000

[Message part 1 (text/plain, inline)]

Dear maintainers,

starting with OpenJDK Java 22 java programs using java.io.Console cannot be testet with dejagnu any more. With JDK 21 it works like a charm.
I belive it has to do with excape sequences that are not filtered out correctly or similar. I am using dejagnu 1.6.3-1, debain package under Ubuntu 24.04.

For an easy reproduction of the bug I have attached a simple example simple.zip. Just unpack it and execute exectest.sh. Be sure to update JAVA_HOME in this script to a jdk 22 or 23 installation.

In testsuite/simple.log some escape sequences are shown were no one are expected:
^[[?1h^[=^[[?2004hhello
^[[?1l^[>^[[?1000l^[[?2004lhello

The attached simple echo example works after simply commenting the lines 13-14 (using Console) and uncommenting lines 16-17 (using BufferedReader) in testsuite/simple.sh.
Alternatively it also works by passing -Djdk.console=java.base to the jvm (1st line in exectest.sh), to trigger the old implementation in JDK.

#!/usr/bin/env -S java --source 23
// #!/usr/local/java/jdk-23.0.1/bin/java --source 23 -Djdk.console=java.base

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class ConsoleTest {

    public static void main(String[] args) throws IOException {
        System.out.print("prompt> ");

        java.io.Console c = System.console();
        String input = c.readLine();

        // BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        // String input = in.readLine();

        System.out.println(input);
        System.out.println("prompt> ");
    }

}

It has something to do with the change of the Java default Console provider to JLine in Java 22.
https://bugs.openjdk.org/browse/JDK-8309141
However, as Java Console works everywhere else (windows/linux console/bash/EclipseIDE internal "console"/IntelliJ internal "console") as far I can see, it seems to be something special with dejagnu.

Thanks for dejagnu, maintaining it, and your help,
Chris

[simple.zip (application/x-zip-compressed, attachment)]

Message #8 received at 75440 <at> debbugs.gnu.org (full text, mbox):

From: Jacob Bachmeyer <jcb62281 <at> gmail.com>
To: Chris Nospam <chris21k <at> gmx.de>, 75440 <at> debbugs.gnu.org
Subject: Re: bug#75440: dejagnu does not like java.io.Console of OpenJDK >= 22
Date: Wed, 8 Jan 2025 19:55:22 -0600

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On 1/8/25 10:44, Chris Nospam via Bug-dejagnu via wrote:
> Dear maintainers,
>
> starting with OpenJDK Java 22 java programs using java.io.Console cannot be testet with dejagnu any more. With JDK 21 it works like a charm.

This is a JVM bug or misfeature.  We have recently had similar problems 
with MinGWGCC tested under Wine. In that case, it was a consequence of 
Wine's new support for Windows quasi-ptys.

> I belive it has to do with excape sequences that are not filtered out correctly or similar. I am using dejagnu 1.6.3-1, debain package under Ubuntu 24.04.

DejaGnu does not and cannot filter escape sequences.  Expect matches the 
patterns it is given.  You can write patterns in your testsuite that 
accommodate or even verify escape sequences from the program under test.

> For an easy reproduction of the bug I have attached a simple example simple.zip. Just unpack it and execute exectest.sh. Be sure to update JAVA_HOME in this script to a jdk 22 or 23 installation.
>
> In testsuite/simple.log some escape sequences are shown were no one are expected:
> ^[[?1h^[=^[[?2004hhello
> ^[[?1l^[>^[[?1000l^[[?2004lhello

The JVM IO facilities are inserting escape sequenceswithout your program 
calling for them. This is a JVM bug or misfeature that Expect (on which 
DejaGnu is built) exposes.

> The attached simple echo example works after simply commenting the lines 13-14 (using Console) and uncommenting lines 16-17 (using BufferedReader) in testsuite/simple.sh.
> Alternatively it also works by passing -Djdk.console=java.base to the jvm (1st line in exectest.sh), to trigger the old implementation in JDK.
>
> #!/usr/bin/env -S java --source 23
> // #!/usr/local/java/jdk-23.0.1/bin/java --source 23 -Djdk.console=java.base
>
> import java.io.BufferedReader;
> import java.io.IOException;
> import java.io.InputStreamReader;
>
> public class ConsoleTest {
>
>      public static void main(String[] args) throws IOException {
>          System.out.print("prompt> ");
>
>          java.io.Console c = System.console();
>          String input = c.readLine();
>
>          // BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
>          // String input = in.readLine();
>
>          System.out.println(input);
>          System.out.println("prompt> ");
>      }
>
> }

First, think about what your program actually does compared to what your 
testsuite code expects it to do.  Examine the message produced at the 
end of the test run in simple.log.  In fact, that message is produced 
*after* echo.exp has completed.  Where does that message come from?

(You will benefit far more from the lesson if you find it for yourself 
than if I tell you.  There is only one place in your testsuite that can 
emit that message.)

Second, the inability to send text to the program under test is not a 
failure:  it is an error and probably an UNRESOLVED test.  A block that 
is executed as a result of catching a Tcl error probably should be 
invoking "error" or possibly "unresolved", not "fail" or even "pass" 
(unless you are testing an error condition).

Third, Tcl interpolates backslash escapes in double-quoted strings.  You 
will need to double (some of) the backslashes and/or review re_syntax(n) 
for Tcl regexp syntax.

Fourth, think about simple_test could actually fail.  That depends on 
what you are trying to do, but any "pass" should have a corresponding 
"fail" somewhere.

(Most of the above refers to Expect code in your 
testsuite/config/default.exp file.)

> It has something to do with the change of the Java default Console provider to JLine in Java 22.
> https://bugs.openjdk.org/browse/JDK-8309141is is not special with DejaGnu; we have recently had similar issues with
>   Wine, encountered while testing mingw32 builds on *nix hosts
> However, as Java Console works everywhere else (windows/linux console/bash/EclipseIDE internal "console"/IntelliJ internal "console") as far I can see, it seems to be something special with dejagnu.

No, the problem is with the JVM and/or your programs and scripts.  It 
appears to work everywhere else because those escape sequences either 
perform terminal control functions or are ignored.  You can write 
regexps that will optionally match and discard the escape sequences.  
Expect exposes this issue because it is strict about matching exactly 
what you tell it to match.


-- Jacob

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Message #11 received at 75440 <at> debbugs.gnu.org (full text, mbox):

From: Chris Nospam <chris21k <at> gmx.de>
To: jcb62281 <at> gmail.com, 75440 <at> debbugs.gnu.org
Subject: Re: bug#75440: dejagnu does not like java.io.Console of OpenJDK >= 22
Date: Tue, 14 Jan 2025 11:12:01 +0000

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[simple.zip (application/x-zip-compressed, attachment)]

Message #14 received at 75440 <at> debbugs.gnu.org (full text, mbox):

From: Chris Nospam <chris21k <at> gmx.de>
To: jcb62281 <at> gmail.com, 75440 <at> debbugs.gnu.org
Subject: Re: bug#75440: dejagnu does not like java.io.Console of OpenJDK >= 22
Date: Tue, 14 Jan 2025 14:11:52 +0000

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[simple.zip (application/x-zip-compressed, attachment)]

Message #17 received at 75440 <at> debbugs.gnu.org (full text, mbox):

From: Jacob Bachmeyer <jcb62281 <at> gmail.com>
To: Chris Nospam <chris21k <at> gmx.de>, 75440 <at> debbugs.gnu.org
Subject: Re: bug#75440: dejagnu does not like java.io.Console of OpenJDK >= 22
Date: Tue, 14 Jan 2025 22:00:04 -0600

[Message part 1 (text/plain, inline)]

[actually you had the new ZIP file on the first message; I can tell 
because the Java program has a loop now]

[also, traditional email discussions use inline responses with a summary 
or further commentary at the end after the response to the last quote; 
please refrain from top-posting if possible]

On 1/14/25 05:12, Chris Nospam wrote:
> Dear Jacob,
> sorry for my late reply and thanks for your rapid and detailed answer. 
> Also I am sorry for the faulty default.exp, it was a quick & dirty 
> version to trigger the bug and only a short snipped of my real project.

That is a new piece of information and I have found other issues that I 
would normally overlook in a small testsuite, but will make problems for 
you in a large testsuite.  More on this below.

> It should only show the problem with the first echo. However, I have 
> enhanced it somehow now, see the attachement.

I see that the new version of your sample program now contains a loop 
instead of exiting unconditionally after the first input. This produces 
a more useful error, complete with a backtrace explaining how you got 
there.  (The framework will call a "${tool}_exit" procedure during 
per-target cleanup if it exists.)

Unfortunately, coordinating the exit of an interactive program is 
tedious because Expect will close the channel upon reading EOF and 
expecting on a closed channel throws an error.  (This should be a hint 
towards one way to solve the problem.)

You should try using runtest's --debug option, which will cause Expect 
to write considerable information about its operation to the "dbg.log" 
file.  That log is particularly useful when seeking to understand why 
patterns do or do not match.

> > Tcl interpolates backslash escapes in double-quoted strings
> I changed now \r\n to \\r\\n in all regular expressions.

It is important to understand what Tcl will do with your code, although 
that particular item "happens to work" either way. (Literal carriage 
return and newline match themselves in Tcl regexps in normal syntax, but 
can make dbg.log harder to read.)

> Please forgive me, I am not an expert in expect script but I try to do 
> my best. I would be happy if you could give me some (direct) advices.

You still need to think about what your test results mean. DejaGnu has 
other status codes because simple PASS/FAIL does not really work in the 
real world.  You should be using "perror" and "unresolved" to report 
inabilities to run the test program.

More concretely, simple_start should clear the prompt_error flag upon 
receiving a prompt and should use "perror" instead of "send_user" to 
report failure to spawn the program.

Similarly, if the prompt_error flag is set, "simple_test" should emit an 
UNRESOLVED result (using the "unresolved" procedure) before returning, 
because the test was not performed due to a run-time condition.

The important rule here is that the total number of test results should 
not change.

Tcl allows optional arguments; you can replace the dispatch logic around 
"simple_test" by using {proc simple_test {expr result {comment ""}} 
...}  (The outer-most brace pair denotes a Tcl code fragment.)

Tcl procedure arguments are also ordinary local variables, so you can do 
{ if {$comment ne ""} {set comment "\[$comment\]"} } in a combined 
"simple_test" if you want.

Think carefully about what you are doing with the "answer" global 
variable.  It should probably be an argument, if not the "result" 
argument that you already have.

Lastly, your "if" conditionals should usually be in braces; this allows 
the Tcl compiler to produce more efficient bytecode.

> I will open a corresponding issue at https://bugreport.java.com and 
> report back a link. Hopefully, they will look into/fix it and not only 
> dismiss that using dejagnu is an edge case.

Hopefully they will at least recognize that a transparent console mode 
is important and ensure that one remains supported.


-- Jacob

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Message #20 received at 75440 <at> debbugs.gnu.org (full text, mbox):

From: Chris Nospam <chris21k <at> gmx.de>
To: jcb62281 <at> gmail.com, 75440 <at> debbugs.gnu.org
Subject: Aw: Re: bug#75440: dejagnu does not like java.io.Console of OpenJDK
 >= 22
Date: Mon, 20 Jan 2025 10:38:27 +0000

[Message part 1 (text/html, inline)]

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