[GROOVY-7184] Problem With Compiler Inconsistency

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.0-beta-4
• Fix Version/s: 2.3.9, 2.4.0-rc-1
• Component/s: Compiler
• Assignee: Cédric Champeau
• Reporter: Jeff Brown
• Created: 26/Nov/14 13:42
• Updated: 23/Dec/14 19:45
• Resolved: 05/Dec/14 08:32

Description

The attached compile problem.zip contains the following code:

src/main/groovy/demo/Config.groovy

package demo

interface Config {}

src/main/groovy/demo/Holders.groovy

package demo

class Holders {
    static setConfig(Config cfg) {}
}

src/main/groovy/demo/Helper.groovy

package demo

class Helper {

    @groovy.transform.CompileStatic
    void test() {

        // with 2.4.0-beta-4 this compiles.
        Config config = new ConfigObject()

        // with 2.4.0-beta-4 this does not compile.
        Holders.config = new ConfigObject()

        // ...with 2.3.7 it all compiles
    }
}

$ ./gradlew cG
:compileJava UP-TO-DATE
:compileGroovy
startup failed:
/Users/jeff/t/compileproblem/src/main/groovy/demo/Helper.groovy: 12: [Static type checking] - Cannot assign value of type groovy.util.ConfigObject to variable of type demo.Config
 @ line 12, column 9.
           Holders.config = new ConfigObject()
           ^

1 error

:compileGroovy FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileGroovy'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 4.552 secs

If I edit build.gradle and change the Groovy version to 2.3.7 it all compiles.

I am not sure why assigning an instance of ConfigObject to a Config reference is allowed. If it is supposed to be allowed because of some proxy generation or something like that, then I am not sure why the property assignment isn't allowed.