C++ parsing error messages

[smu-sc-gj]

Hi all,

A group of students suspected of working together produced code which compiles, but crashes 5.0 and causes errors on 2.12.1 (which I happened to still have on my machine).

The offending code:

 if (evt.keysym.sym == 'lmb')

The error on 5.0 is:

failed to parse 'projectName_XXXX/Name.cpp'Cannot invoke "de.jplag.cpp.grammar.CPP14Parser$PointerDeclaratorContext.noPointerDeclarator()" because the return value of "de.jplag.cpp.grammar.CPP14Parser$DeclaratorContext.pointerDeclaParsing Submissions    33% [========                 ] 1/3 (0:00:02 / 0:00:04)

The error on 2.12.1 is:

[projectName_XXXX]
  Scanning Error in 'src/Name.cpp':
  Lexical error at line 430, column 29.  Encountered: "m" (109), after : "\'l"

I used this error message to modify the line so it would parse and I now have reports from both. The error message from the older version is much easier to read and allows for exploration, the 5.0 error message less so.

I appreciate this needs further investigation with the latest version etc. I'll try to create a MWE for this when I have more time.

[TwoOfTwelve]

I've tried to replicate the issue using the following code:

void main() {
    if (evt.keysym.sym == 'lmb') {
    }
}

JPlag was able to process this without any problem, so I guess it depends on the surrounding code.

Do you have the option of sending the entire file or can you create a short example that encounters the error?

[smu-sc-gj]

While the original code is only a few files, there were some really big dependencies. The relevant one here being Ogre (the evt.keysym.sym comes from OgreBites. I've managed to re-create the issue with the following code:

#include <iostream>
#include <stdlib.h>

typedef int Keycode;

struct Keysym {
    Keycode sym;
    unsigned short mod;
};

struct KeyboardEvent {
    int type;
    Keysym keysym;
    unsigned char repeat;
};

bool keyProcessing(const KeyboardEvent& evt)
{
    std::cout << "Processing Key" << std::endl;

    if(evt.keysym.sym == 'w')
    {
        std::cout << "W" << std::endl;
    }
    
    /* I know this doesn't make sense ... but it's 
       what they original code was trying to do. */
       
    if(evt.keysym.sym == 'lmb')
    {
        std::cout << "Left Mouse Button" << std::endl;
    }
  
    return true;
}

int main(int argc, char** argv) 
{
  KeyboardEvent test;
  test.keysym.sym = 'w';
  
  keyProcessing(test);

  exit(EXIT_SUCCESS);
}

I created three copies of this file as a sample.

• Latest version (5.1.0) language set to cpp, I have a note that says this only works if the code is C++14 compatible throughout, the samples are but I'm not sure the student submission are.

java -jar ~/Applications/JPlag/jplag-5.1.0-jar-with-dependencies.jar -l cpp .
Loading Submissions   100% [=========================] 3/3 (0:00:00 / 0:00:00) 
Parsing Submissions   100% [=========================] 3/3 (0:00:00 / 0:00:00) 
Comparing Submissions 100% [=========================] 3/3 (0:00:00 / 0:00:00) 
2024-07-04-10:04:23_440 [INFO] JPlag - Total time for comparing submissions: 0h 00min 00s 024ms
2024-07-04-10:04:23_442 [INFO] ClusteringFactory - Calculating clusters via spectral clustering with cumulative distribution function pre-processing...
Finding clusters  < <+>                            > 0:00:00
2024-07-04-10:04:24_006 [INFO] ReportObjectFactory - Start writing report...
2024-07-04-10:04:24_007 [INFO] ReportObjectFactory - Start to export results...
2024-07-04-10:04:24_100 [INFO] ReportObjectFactory - Total Comparisons: 3. Comparisons in Report: 3. Omitted Comparisons: 0.
2024-07-04-10:04:24_153 [INFO] OutputFileGenerator - Successfully written the result: results.zip
2024-07-04-10:04:24_154 [INFO] OutputFileGenerator - View the result using --mode or at: https://jplag.github.io/JPlag/

• Latest version (5.1.0) with language set to c:

java -jar ~/Applications/JPlag/jplag-5.1.0-jar-with-dependencies.jar -l c .
Loading Submissions   100% [=========================] 4/4 (0:00:00 / 0:00:00) 
Parsing Submissions     0% [                               ] 0/4 (0:00:00 / ?) 
2024-07-04-10:04:53_285 [WARN] Submission - Failed to parse submission three.cpp:
failed to parse 'three.cpp'Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"
2024-07-04-10:04:53_287 [WARN] Submission - Failed to parse submission two.cpp:
failed to parse 'two.cpp'Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"
2024-07-04-10:04:53_288 [WARN] Submission - Failed to parse submission one.cpp:
failed to parse 'one.cpp'Lexical error at line 29, column 28.  Encountered: "m" Parsing Submissions   100% [=========================] 4/4 (0:00:00 / 0:00:00) 
2024-07-04-10:04:53_296 [INFO] Submission - Summary of all errors:
2024-07-04-10:04:53_271 [ERROR] Submission - ERROR: nothing to parse for submission "results.zip"
2024-07-04-10:04:53_310 [INFO] SubmissionSetBuilder - Summary of all errors:
2024-07-04-10:04:53_227 [ERROR] SubmissionSetBuilder - Ignore submission with invalid suffix: results.zip
2024-07-04-10:04:53_310 [INFO] Scanner - Summary of all errors:
2024-07-04-10:04:53_285 [ERROR] Scanner - Scanning Error in 'three.cpp': Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"
2024-07-04-10:04:53_287 [ERROR] Scanner - Scanning Error in 'two.cpp': Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"
2024-07-04-10:04:53_288 [ERROR] Scanner - Scanning Error in 'one.cpp': Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"
2024-07-04-10:04:53_310 [INFO] CLI - Summary of all errors:
2024-07-04-10:04:53_296 [ERROR] CLI - Not enough valid submissions! (found 0 valid submissions)
2024-07-04-10:04:53_310 [INFO] SubmissionSet - Summary of all errors:
2024-07-04-10:04:53_271 [ERROR] SubmissionSet - ERROR -> Submission results.zip removed
2024-07-04-10:04:53_286 [ERROR] SubmissionSet - ERROR -> Submission three.cpp removed
2024-07-04-10:04:53_287 [ERROR] SubmissionSet - ERROR -> Submission two.cpp removed
2024-07-04-10:04:53_288 [ERROR] SubmissionSet - ERROR -> Submission one.cpp removed

• Legacy version (2.12.1) with language set to c/c++

java -jar ~/Applications/JPlag/jplag-2.12.1-SNAPSHOT-jar-with-dependencies.jar -l c/c++ .
Language accepted: C/C++ Scanner [basic markup]
Command line: -l c/c++ . 
initialize ok
3 submissions
  Scanning Error in 'one.cpp':
  Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"
  Scanning Error in 'three.cpp':
  Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"
  Scanning Error in 'two.cpp':
  Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"

0 submissions parsed successfully!
3 parser errors!


Error: Not enough valid submissions! (only 0 are valid):
[one.cpp]
  Scanning Error in 'one.cpp':
  Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"

[three.cpp]
  Scanning Error in 'three.cpp':
  Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"

[two.cpp]
  Scanning Error in 'two.cpp':
  Lexical error at line 29, column 28.  Encountered: "m" (109), after : "\'l"

I hope this helps!

[tsaglam]

* Latest version (5.1.0) language set to `cpp`, I have a note that says this only works if the code is C++14 compatible throughout, the samples are but I'm not sure the student submission are.

Seems to work with the cpp language module.

* Latest version (5.1.0) with language set to `c`:

This language module is the former c/c++ module from the JPlag legacy version. We still provide it with JPlag, however we are not actively working on it. If anyone wants to provide a fix here, feel free to create a PR.