[Bug] Dot exporting of CPG generates an invalid dot file

[ssierral]

Describe the bug

When using joern-export to export a CPG in dot format, it fails to escape special characters (e.g., %d) or double quotes inside the CODE attribute of each node. Thus the generated dot file is not valid.

To Reproduce
I used exactly the same x42.c file which is provided in the quickstart guide.

1. joern-parse x42.c
2. joern-export --repr=cpg --format=dot cpg.bin
3. Using pydot in python: graph = pydot.graph_from_dot_file("out/x42.c/main.dot")[0]
4. See error:

30064771079[label=CALL ARGUMENT_INDEX="-1" CODE="printf("What is the meaning of life?\n")" COLUMN_NUMBER="3" DISPATCH_TYPE="STATIC_DISPATCH" LINE_NUMBER="10" METHOD_FULL_NAME="printf" NAME="printf" ORDER="2" SIGNATURE="" TYPE_FULL_NAME="ANY"]
             ^
Expected '}', found '['  (at char 23), (line:2, col:14)

5. After escaping (\") all double quotes and special chars inside CODE attribute, the dot file can be read correctly.

Expected behavior
joern-export should automatically escape invalid characters inside node attribute fields.

Screenshots

Desktop (please complete the following information):

• OS: Ubuntu 20.04
• Joern Version: 4.0.87
• Java version: 21.0.4

Additional context