Error Occurred While Parsing Shift Operators in Java

[Qeryu]

When I performed a reduction on the following Java code, I encountered some issues.

#!/bin/bash

set -o pipefail
set -o nounset

rm T.class
javac T.java \
&& timeout -s 9 5 java T | grep -q '4'

public class T {

    private static int counter() {
        return 100;
    }

    public static void main(String[] args) {
        for (int i = 0; i < counter(); ++i) {
            System.out.println(1<<2);
        }
    }

}

During the reduction, Perses generated the following error message.

$ java -jar perses_deploy.jar --test-script r.sh --input-file T.java 
[10:13:12] [INFO   ] Tree Building: Start building spar-tree from input file SourceFile{file=/home/qeryu/others/perses_java_issue/T.java, lang=org.perses.grammar.java.LanguageJava@5e3a8624} 
[10:13:12] [INFO   ] Tree Building: Step 1: Antlr parsing. 
[10:13:12] [INFO   ] Tree Building: Step 2: Converting parse tree to spar-tree 
[10:13:12] [INFO   ] Tree Building: Step 3: Simplifying spar-tree 
[10:13:12] [INFO   ] Tree Building: Finished in TimeSpan{startMillis=1705457592389, endMillis=1705457592904, formatted=0 seconds} 
[10:13:12] [INFO   ] The reduction process started at 10:13:12 2024/01/17 
[10:13:12] [INFO   ] Cache setting: query-caching=enabled, edit-caching=enabled 
[10:13:12] [INFO   ] Reduction algorithm is org.perses.reduction.reducer.PersesNodePrioritizedDfsReducer 
[10:13:13] [SEVERE ] ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** 
[10:13:13] [SEVERE ] * 
[10:13:13] [SEVERE ] * The initial sanity check failed. 
[10:13:13] [SEVERE ] * The files have been saved, and you can check them at: 
[10:13:13] [SEVERE ] *     /tmp/1705457593470-0 
[10:13:13] [SEVERE ] * 
[10:13:13] [SEVERE ] ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** 
Exception in thread "main" java.lang.IllegalStateException
        at org.perses.reduction.ReductionDriver.sanityCheck(ReductionDriver.kt:343)
        at org.perses.reduction.ReductionDriver.reduce(ReductionDriver.kt:114)
        at org.perses.Main.run(Main.java:92)
        at org.perses.Main.main(Main.java:47)

Upon checking /tmp/1705457593470-0, I found that the Java code was parsed as follows:

...

{
System
.
out
.
println
(
1
<
<
2
)
;
}

...

In lines 11-12, the left shift operator was parsed as two less than signs, which I believe is an incorrect parse. When reducing C language code that uses shift operators, it can be parsed correctly.

Could this parsing error be due to an issue with how I'm using Perses?

[chengniansun]

Thank you for your bug report. I will release a fix soon.

Meanwhile, can you try the flag --code-format with the value COMPACT_ORIG_FORMAT.

https://github.com/uw-pluverse/perses/blob/cbc9a99bb61381881e2afddf293db3dcbac51424/test/org/perses/golden_perses_cmd_usage.txt#L34

[Qeryu]

Thanks, it works

[chengniansun]

Tracked with the internal issue 486

[chengniansun]

This is fixed in the internal repo, and will cut a release soon.