[GROOVY-11192] Code that causes Groovy Compiler Crash

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.15
• Fix Version/s: 3.0.20, 5.0.0-alpha-3, 4.0.16
• Component/s: Static Type Checker
• Labels: Generics compiler crash parametize type
• Environment: I am running on MacBook Pro, but I think this is a probably regardless of environment. I have been able to repeat this bug for Groovy versions from 3.0.10 to 4.0.15 and all in between.
• Flags: Important

Language

groovy

• Assignee: Eric Milles
• Reporter: John DeRegnaucourt
• Created: 14/Oct/23 16:59
• Updated: 22/Dec/23 11:38
• Resolved: 23/Oct/23 13:10

Description

When attempting to compile the code below, it causes the Groovy compiler to crash with:

java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1
        at org.codehaus.groovy.ast.tools.GenericsUtils.createGenericsSpec(GenericsUtils.java:494)
        at org.codehaus.groovy.ast.tools.GenericsUtils.createGenericsSpec(GenericsUtils.java:480)
        at org.codehaus.groovy.ast.tools.GenericsUtils.parameterizeType(GenericsUtils.java:293)

The crash is caused because the GenericType parameter is missing on line 9 in TestCompilerCrashOnTemplateArgCount:

private Map<Long, String> map = new MapLong<>()   // causes compiler crash

...but

private Map<Long, String> map2 = new MapLong<String>() // doest not cause compiler crash

1st source file (TestCompilerCrashOnTemplateArgCount.groovy)

package com.x.y.z
import groovy.transform.CompileStatic
@CompileStatic
class TestCompilerCrashOnTemplateArgCount
{
    // The line below crashes Groovy Compiler with ArrayOutOfBoundsException during compilation because no type argument passed to MapLong<>()
    private Map<Long, String> map = new MapLong<>()
    
    // The line below doesn't crash the compiler:
    private Map<Long, String> map2 = new MapLong<String>()
}

2nd source file (MapLong.groovy):

package com.x.y.z
import groovy.transform.CompileStatic
@CompileStatic
class MapLong<V> implements Map<Long, V>
{
    int size() { return 0  }
    boolean isEmpty() { return false }
    boolean containsKey(Object key) { return false }
    boolean containsValue(Object value) { return false }
    V get(Object key) { return null }
    V put(Long key, V value) { return null }
    V remove(Object key) { return null }
    void putAll(Map<? extends Long, ? extends V> m) { }
    void clear() { }
    Set<Long> keySet() { return null }
    Collection<V> values() { return null }
    Set<Entry<Long, V>> entrySet() { return null }
}

 

The compiler is expecting one argument, but a no argument array was allocated.  When it attempts to access the array at element [0], the compiler hits ArrayOutOfBoundsException.

 

This is super easy to repeat with the two tiny source files attached.

Issue Links

• links to: GitHub Pull Request #1970