Go 1.10 was supposed to change the jclass JNI type to map to Go
uintptr, but failed to map the Android NDK definition until
recently.
There was a single instance in the reverse binding generator that
compared jclass values to nil. Change it to use 0 and cast the
jclass value to uintptr to ensure compatibility with older Go
releases.
Change-Id: Ifa22ed2db556220b7dfd0076b004bd8930219e08
Reviewed-on: https://go-review.googlesource.com/124915
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
The gobind and gomobile bind tools have historically overlapped:
gobind outputs generated bindings, and gomobile bind will generate
bindings before building them. However, the gobind bindings were
never used for building and thus allowed to not be complete.
To simplify version control, debugging, instrumentation and build
system flexibility, this CL upgrades the gobind tool to be the
canonical binding generator and change gomobile bind to use gobind
instead of its own generator code.
This greatly simplifies gomobile bind, but also paves the way to skip
gomobile bind entirely. For example:
$ gobind -outdir=$GOPATH golang.org/x/mobile/example/bind/hello
$ GOOS=android GOARCH=arm64 CC=<ndk-toolchain>/bin/clang go build -buildmode=c-shared -o libgobind.so gobind
$ ls libgobind.*
libgobind.h libgobind.so
The same applies to iOS, although the go build command line is more
involved.
By skipping gomobile it is possible to freely customize the Android
or iOS SDK level or any other flags not supported by gomobile bind.
By checking in the generated source code, the cost of supporting
gomobile in a custom build system is also decreased.
Change-Id: I59c14a77d625ac1377c23b3213672e0d83a48c85
Reviewed-on: https://go-review.googlesource.com/99316
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
If a wrapped Java class is missing at runtime, for example because
the app is running on an older Android version, the resulting class
not found exception would cause the app to crash. Fix it by ignoring
missing classes, allowing the app to avoid using them according to a
runtime version check.
Change-Id: I9138c4e2a905b180959306ecbb997695236ab273
Reviewed-on: https://go-review.googlesource.com/35853
Reviewed-by: David Crawshaw <crawshaw@golang.org>
For Java classes implemented in Go, it is useful to take a Java instance
and extract its wrapped Go instance. For example, consider the
java.lang.Runnable implementation wrapping a Go function:
package somepkg
type GoRunnable struct {
lang.Runnable
f func()
}
Java methods that take a java.lang.Runnable cannot directly take a
*GoRunnable, so this CL adds a Unwrap method:
import gorun "Java/somepkg/GoRunnable"
...
r := gorun.New()
r.Unwrap().(*GoRunnable).f = func() { ... }
javapkg.Run(r)
The extra interface conversion is unfortunately needed to avoid
import cycles.
Change-Id: Ib775a5712cd25aa75a19d364a55d76b1e11dce77
Reviewed-on: https://go-review.googlesource.com/35295
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Before this CL, calling overloaded methods on reverse bound Java
classes and interfaces involved confusing and ugly name mangling.
If a set of methods with the same name differed only in argument count,
the mangling was simply adding the argument count to the name:
func F()
func F1(int32)
But if two or more methods had the same number of arguments, the type
had to be appended:
func (...) F() int32
func (...) F1(int32) (int32, error)
func (...) F__I(int32, int32)
func (...) F__JLjava_util_concurrent_TimeUnit_2(int64, concurrent.TimeUnit)
This CL sacrifices a bit of type safety and performance to regain the
convenience and simplicity of Go by resolving overloaded method dispatch
at runtime.
Overloaded Java methods are combined to one Go method that, when invoked,
determines the correct Java method variant at runtime.
The signature of the Go method is compatible with every Java method with
that name. For the example above, the single Go method becomes the most
general
func (...) F(...interface{}) (interface{}, error)
The method is variadic to cover function with a varying number of
arguments, and it returns interface{} to cover int32, int64 and no
argument. Finally, it returns an error to cover the variant that returns
an error. The generator tries to be specific; for example
func G1(int32) int32
func G2(int32, int32) int32
becomes
func G(int32, ...int32) int32
Overriding Java methods in Go is changed to use the Go parameter types to
determine to correct Java method. To avoid name clashes when overriding
multiple overloaded methods, trailing underscores in the method name are
ignored when matching Java methods. See the Get methods of GoFuture in
bind/testpkg/javapkg for an example.
Change-Id: I6ac3e024141daa8fc2c35187865c5d7a63368094
Reviewed-on: https://go-review.googlesource.com/35186
Reviewed-by: David Crawshaw <crawshaw@golang.org>
This CL restructures function generation to match the way methods
are generated, to avoid two different code paths for a coming CL.
Change-Id: I5a4f15e51ea5df101f9aa419ed4170ab36506418
Reviewed-on: https://go-review.googlesource.com/35185
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The filepath package works on native paths, not package paths. Replace
it with the path package. Do it for Objective-C as well, for correctness.
No new tests; the existing reverse tests fails on Windows without
this CL.
Change-Id: I8963db992d4bed30e8828579fb83ecaf8c9d9ade
Reviewed-on: https://go-review.googlesource.com/35176
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
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>
