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>
The return value of a JNI call is undefined when an exception was
raised during the call. To make sure comparisons with NULL works,
clear the value when an exception is raised.
No new tests; some devices, like the Samsung S2, crashes with the
existing tests without this CL.
Change-Id: I85eb983e9444fff1f05e0f83a0640d106280e54d
Reviewed-on: https://go-review.googlesource.com/34631
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Generate Cast functions that take a proxy for a Java class or interface,
and return a new proxy with the same reference. The Cast functions
panic if the underlying Java object is not an instance of the expected
type.
Change-Id: I08a5bf9a79139f0fac5dd102c7b028c8c989fc6d
Reviewed-on: https://go-review.googlesource.com/30095
Reviewed-by: David Crawshaw <crawshaw@golang.org>
CL 24800 changed the error representation from strings to objects.
However, since native errors types are not immediately compatible
across languages, wrapper types were introduced to bridge the gap.
This CL remove those wrappers and instead special case the error
proxy types to conform to their language error protocol.
Specifically:
- The ObjC proxy for Go errors now extends NSError and calls
initWithDomain to store the error message.
- The Go proxy for ObjC NSError return the localizedDescription
property for calls to Error.
- The Java proxy for Go errors ow extends Exception and
overrides getMessage() to return the error message.
- The Go proxy for Java Exceptions returns getMessage whenever
Error is called.
The end result is that error values behave more like normal objects
across the language boundary. In particular, instance identity is
now preserved: an error passed across the boundary and back will
result in the same instance.
There are two semantic changes that followed this change:
- The domain for wrapped Go errors is now always "go".
The domain wasn't useful before this CL: the domains were set to
the package name of function or method where the error happened
to cross the language boundary.
- If a Go method that returns an error is implemented in ObjC, the
implementation must now both return NO _and_ set the error result
for the calling Go code to receive a non-nil error.
Before this CL, because errors were always wrapped, a nil ObjC
could be represented with a non-nil wrapper.
Change-Id: Idb415b6b13ecf79ccceb60f675059942bfc48fec
Reviewed-on: https://go-review.googlesource.com/29298
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The Java API wrapper generator use interface{} for Java classes
that no Go code references. Return values of unknown types are thrown
away, since they're effectively useless. Since the return values can
be used for nil checks and since casting of Java instances are
supported in CL 30095, this CL returns the naked *seq.Ref results
values instead.
Change-Id: I821b1c344a4c68c57fd34e2b655404e449de4c03
Reviewed-on: https://go-review.googlesource.com/30097
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The ClassGen.genGo function always uses unsafe, contrary to what
the check in GenGo says. With this CL, generated code always
imports unsafe if there are any classes to be generated.
Change-Id: Ic807111a26e494b4941790830b1950bb8b1f73d5
Reviewed-on: https://go-review.googlesource.com/29873
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Using the new Java class analyzer API, scan the bound packages
for references to Java classes and interfaces and generate Go
wrappers for them.
This is the second part of the implementation of proposal golang/go#16876.
For golang/go#16876
Change-Id: I59ec0ebdae0081a615dc34d450f344c20c03f871
Reviewed-on: https://go-review.googlesource.com/28596
Reviewed-by: David Crawshaw <crawshaw@golang.org>
