[GROOVY-7363] Frequent compilation error on cascading generic types

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.2
• Fix Version/s: 2.4.6
• Component/s: Static Type Checker
• Labels: test
• Environment: MacOS X; Oracle JDK 1.7u75 / 1.8u40; Maven 3.0.5
• Assignee: Pascal Schumacher
• Reporter: Frank Pavageau
• Created: 23/Mar/15 05:35
• Updated: 22/Mar/24 13:40
• Resolved: 03/Nov/15 18:07

Description

Most of the time, I get the following compilation error:

[ERROR] /Users/fpavageau/devs/bugs/lost-cascading-types/src/main/groovy/BadType.groovy: 22: [Static type checking] - No such property: start for class: T
[ERROR] @ line 22, column 22.
[ERROR] println("" + rel.currentState.state.start)
[ERROR] ^
[ERROR] 
[ERROR] 1 error

where rel is an instance of a non-parameterized (Java) class implementing a generic interface with the currentState generic property. So the type of the property should actually be known, but it's lost and I get a compilation error because the start property is not part of the lower-bound type of currentState.

When I say "most of the time", it's because the compilation error is not always triggered (so lots of debugging fun!). I've tried with Oracle JDK 1.7u75 and 1.8u40, and I get around 87% of failures:

JDK 1.7

$ failures=0; for i in {1..100}; do mvn clean package > /dev/null 2>&1 || ((failures++)); done; echo $failures
87

JDK 1.8

$ failures=0; for i in {1..100}; do mvn clean package > /dev/null 2>&1 || ((failures++)); done; echo $failures
88

I'm attaching a test case, which is also available on Github.

Issue Links

• relates to: GROOVY-11341 @CompileStatic: Compilation fails due to a synthetic bridge method in the subclass