[GROOVY-11391] GroovyClassLoader hangs on parsing certain types of scripts

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.0.19, 3.0.21, 4.0.21
• Component/s: ast builder, class generator, Compiler, parser, parser-antlr4

Language

groovy

• Assignee: Unassigned
• Reporter: Fridman Viktor
• Created: 30/May/24 10:35
• Updated: 20/Jun/24 16:53

Description

i have a simple sample of code:

String script = "import com.atlassian.jira.component.ComponentAccessor\n" +
    "\n" +
    "Set<String> asdf1 = [\n" +
    "        \"abc\"\n" +
    "] as Set<String>\n" +
    "\n" +
    "Set<String> asdf2 = [\n" +
    "        \"def\"\n" +
    "] as Set<String>\n" +
    "\n" +
    "Set<String> asdf3 = [\n" +
    "        \"qwer\",\n" +
    "        \"wert\"\n" +
    "] as Set<String>\n" +
    "\n" +
    "Set<String> asdf4 = [\n" +
    "        \"qwerty\"\n" +
    "] as Set<String>\n" +
    "\n" +
    "Set<String> asdf5 = [\n" +
    "        \"asdvlkjn\",\n" +
    "        \"asdlvkasdlkvm\",\n" +
    "        \"asdviamsdov\",\n" +
    "        \"zxcv\",\n" +
    "        \"vcxz\",\n" +
    "        \"xcvb\",\n" +
    "        \"bvcx\"\n" +
    "] as Set<String>\n" +
    "\n" +
    "Set<String> asdf6 = [ // qwer ty \"asdf\"\n" +
    "        \"dfbjknsldfkb \",\n" +
    "        \"bvcxcx\",\n" +
    "        \"xcvbbv\",\n" +
    "        \"bvcx\",\n" +
    "        \"xcvb\"\n" +
    "] as Set<String>\n" +
    "\n" +
    "Set<String> asdf7 = [ //aqwerty\n" +
    "        \"asdfghj\",\n" +
    "        \"jhgfdsa\",\n" +
    "        \"asdfg\",\n" +
    "        \"gfdsa\"\n" +
    "] as Set<String>\n" +
    "\n" +
    "Set<String> asdf8 = [ //qwerrty\n" +
    "        \"zxcv\",\n" +
    "        \"vcxz\",\n" +
    "        \"xcvbbnm,.\"\n" +
    "] as Set<String>";


GroovyClassLoader gcl = new GroovyClassLoader();
GroovyCodeSource codeSource = new GroovyCodeSource(script, "Script", "/groovy/script");


long l = System.currentTimeMillis();
try {
    Class aClass = gcl.parseClass(codeSource);
    System.out.println(aClass);
}
catch (Exception e) {
    long l1 = System.currentTimeMillis();
    System.out.println(l1 - l);
}

code parsing hangs for a looooooooong time.

but if i add ';' after every string like

] as Set<String>

so it will look like

] as Set<String>;

in groovy-script, it works fast.

 

the problem seems somewhere deep in ParserATNSimulator, its configurations or predictive parsing at all (seems quite greedy) - randomly stopped debugger shows that while it hangs:

 

i understand that the code of script could have errors (for example, import could not be found or smthng else), but i think that the parser hanging is quite abnormal

 

in pom tried both (separately ofc):
implementation 'org.apache.groovy:groovy-all:4.0.21'

implementation 'org.codehaus.groovy:groovy-all:3.0.21'