Before this CL, Java types that were only implicitly referenced
were represented as interface{}. However, if a value of such an
implicit type were passed to Java, a runtime crash would occur
because there would be no wrapper class to unwrap.
Fix this by generating implicit types, fixing the crashes,
gaining type safety, and removing the interface{} special case in
the generator.
While we're here, remove a redundant insert to the clsMap map in
java.go.
Change-Id: Ic50125da3d7cd6075899bf628d419b084c630490
Reviewed-on: https://go-review.googlesource.com/34777
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Before this CL, the type of the implicit "this" parameter to Java methods
implemented in Go could only be a super class of the generated Java
class. For example, the following GoRunnable type is an implementation of
the Java interface java.lang.Runnable with a toString method:
package somepkg
import "Java/java/lang"
type GoRunnable struct {
lang.Runnable
}
func (r *GoRunnable) ToString(this lang.Runnable) string {
...
}
The "this" parameter is implicit in the sense that the reverse generator
automatically fills it with a reference to the Java instance of
GoRunnable.
Note that "this" has the type Java/java/lang.Runnable, not
Java/go/somepkg.GoRunnable, which renders it impossible to call Java
methods and functions that expect GoRunnable. The most practical example
of this is the Android databinding libraries.
This CL changes the implicit this parameter to always match the exact
type. In the example, the toString implementation becomes:
import gopkg "Java/go/somepkg"
func (r *GoRunnable) ToString(this gopkg.GoRunnable) string {
...
}
One strategy would be to simply treat the generated Java classes
(GoRunnable in our example) as any other Java class and import it
through javap. However, since the Java classes are generated after
importing, this present a chicken-and-egg problem.
Instead, use the newly added support for structs with embedded prefixed types
and synthesize class descriptors for every exported Go struct type.
Change-Id: Ic5ce4a151312bd89f91798ed4088c9959225b448
Reviewed-on: https://go-review.googlesource.com/34776
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Accept Java API interface types as arguments and return values from
bound Go package functions and methods. Also, allow Go structs
to extend Java classes and implement Java interfaces as well as override
and implement methods.
This is the third and final part of the implementation of the golang/go#16876
proposal.
Fixesgolang/go#16876
Change-Id: I6951dd87235553ce09abe5117a39a503466163c0
Reviewed-on: https://go-review.googlesource.com/28597
Reviewed-by: David Crawshaw <crawshaw@golang.org>
