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60 Commits

Author SHA1 Message Date
Elias Naur
3884e8cb98 internal,bind: resolve overloaded methods at runtime
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>
2017-01-17 14:03:33 +00:00
Elias Naur
c90c4f7c8a bind,internal: change the default Java package to the empty string
The Objective-C bindings was recently changed to support the empty
name prefix and to use that as the default. This CLs changed the Java
generators in the same way, supporting the empty Java package and using
it as the default.

Change-Id: I857affce686c67638a2b6c4e1da5d6a88d7ba560
Reviewed-on: https://go-review.googlesource.com/34778
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2017-01-11 19:15:09 +00:00
Elias Naur
ff6f6e8d8e bind,cmd,internal: generate reverse bindings for exported Go structs
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>
2017-01-11 19:06:53 +00:00
Elias Naur
e0bb90a948 bind: clear JNI return values when an exception was raised
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>
2016-12-27 15:54:01 +00:00
Elias Naur
e107ad8ed2 bind: sanitize parameter names
Package names, type names and method names are already sanitized.
Extend that to parameter names as well.

Change-Id: I408024c5e2f9561c37e8059a2b53199ee1afaef6
Reviewed-on: https://go-review.googlesource.com/31519
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-10-21 09:25:03 +00:00
Péter Szilágyi
2ea7e2cc92 bind, bind/java: support generating exceptional constructors
In Go type constructors can often return an error type too
beside an instance of the type being created. This is useful
in cases where the parameters might be wrong and instantiaion
cannot succeed. This CL extends the Java generator so that
these methods are also converted into class constructors that
also can throw.

Change-Id: I5e531eec126904a026767a8503968255b9fd833b
Reviewed-on: https://go-review.googlesource.com/31184
Reviewed-by: Elias Naur <elias.naur@gmail.com>
2016-10-17 14:21:52 +00:00
Elias Naur
1c49d29d1c bind,cmd: accept ObjC wrapper types in bound packages
Accept ObjC API wrapper types as arguments and return values from
bound Go package functions and methods. Also, allow Go structs
to extend ObjC classes and implement ObjC protocols as well as override
and implement methods.

This is the third and final part of the implementation of the golang/go#17102
proposal.

Fixes golang/go#17102

Change-Id: I601d90fb6d22b8d6f8b7d5fe0130daa1a4dd4734
Reviewed-on: https://go-review.googlesource.com/29175
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-10-17 10:37:16 +00:00
Elias Naur
63993740dd bind: fix field accessors for Go implemented Java classes
The go_seq_to_refnum function handles its argument object as a Java
object if it doesn't implement Seq.Proxy. Java classes implemented in
Go does not implement Seq.Proxy, but when passing "this" references to
Go, instances must be treated as a Go object.

Use go_seq_to_refnum_go everywhere "this" is passed to Go, which fixes
field accessors and simplifies the method call case.

Change-Id: I3d01c63d7b2081e6344ece431f5e5021a9dd7662
Reviewed-on: https://go-review.googlesource.com/31171
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-10-17 10:26:22 +00:00
Elias Naur
a82bb3c8ba cmd/gobind,bind: generate complete Java interface with gobind
Output every Java class, including the support classes, from gobind
-lang=java. In addition, replace Go package export data parsing with
converting from go/ast to go/types. That way, gobind can tolerate
unknown imports as long as the exported Go API doesn't use them.

In a follow-up CL, the gobind gradle plugin will use gobind for a first
pass to expose the generated Java classes to the android plugin.

Change-Id: I8134899ec818c7fee79e4d9df8afcae9dd679add
Reviewed-on: https://go-review.googlesource.com/30093
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-10-14 13:14:45 +00:00
Russ Cox
a4f0a77f2f bind: param name replacement for invalid unicode names
The are three generators that currently call this method:
    A  -> B
(1) go -> java
(2) go -> objective-c
(3) go -> go

As discussed below, we only substitute for invalid unicode characters
in case (1).

**Case 1**
Go:
From golang.org/ref/spec:
Identifiers name program entities such as variables and types.
An identifier is a sequence of one or more letters and digits(unicode_digit).
The first character in an identifier must be a letter(unicode_letter | "_" ).

Java:
From https://docs.oracle.com/javase/specs/jls/se7/html/jls-3.html#jls-3.8
`The "Java letters" include uppercase and lowercase ASCII Latin letters
A-Z (\u0041-\u005a), and a-z (\u0061-\u007a), and, for historical reasons,
the ASCII underscore (_, or \u005f) and dollar sign ($, or \u0024). The $
character should be used only in mechanically generated source code or,
rarely, to access pre-existing names on legacy systems.`

Therefore, Go's identifiers are checked in case they break these Java rules.

**Case 2**
There is no objective-c standard specification for valid identifiers.
From some testing it seems that Go and objective-c have identical
valid identifier rules.

**Case 3**
Requires no checking.

Change-Id: I881810eb9355af6a418727ace32cb6ce4266b2a0
Reviewed-on: https://go-review.googlesource.com/14044
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-10-12 18:37:41 +00:00
Elias Naur
69dc8e1c38 bind: allow implicit this argument on every exported method
Before this CL, the implicit `this` arguments to methods on Java classes
implemented in Go was only supported on overriding methods, because
their parameter count are known. This CL expands support for the `this`
parameter to every exported method. It only recognizes parameters named
`this` declared with a Java wrapper type.

Change-Id: I8a9d3417d259bdfcc28512a72f07d6a05f483adc
Reviewed-on: https://go-review.googlesource.com/30276
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-10-05 07:49:55 +00:00
Elias Naur
3f7b83ffd4 bind: generate Java constructors for every exported struct
A recent CL added Java constructors to generated classes that extends
or implements other Java classes and interfaces. Constructors for a
struct S are Go functions on the form

func NewS...(...) *S

If no such constructors exists, a default empty constructor is
generated.

Expand that to cover every exported Go struct.

Fixes golang/go#17086

Change-Id: I910aba13d5884c3f67c946c62a8ac4a3db8e2ea7
Reviewed-on: https://go-review.googlesource.com/29710
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-10-05 07:47:24 +00:00
Elias Naur
89b8360218 bind: remove error wrappers to preserve error instance identity
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>
2016-10-04 09:11:42 +00:00
Elias Naur
9d5f7955ff bind: correctly generate methods with implicit this and parameters
Change-Id: I885a21876d9f639bc0996c9279fd0afefa93cef6
Reviewed-on: https://go-review.googlesource.com/29877
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-09-30 14:05:34 +00:00
Elias Naur
2dcaa053a0 bind: preserve no-arg Java constructors
When the Java class parser began culling unused constructors, the
logic for determining whether a given Java class has a no-arg
constructor broke when the no-arg constructor is culled. Add
an explicit field for tracking the no-arg constructor property.

Change-Id: Ib68929ae1108bd6fa1fd23de1d134332eb0d97a2
Reviewed-on: https://go-review.googlesource.com/29875
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-09-30 14:00:14 +00:00
Péter Szilágyi
1663ffa95c bind: initialize JNI library on any class load
With the introduction of constructors Java side, all types
become entry points into the library. However the library
was only initialized by the main class until now, resulting
in all other constructors hitting linker errors until an
interaction with the main library class.

This CL fixes that by changing each generated type to touch
the main library class, ensuring that the underlying native
library is loaded.

Change-Id: I640d1dc329e072f8d0753f74ccce87cd9e5aaea8
Reviewed-on: https://go-review.googlesource.com/29994
Reviewed-by: Elias Naur <elias.naur@gmail.com>
2016-09-29 11:31:45 +00:00
Elias Naur
bdf873ed8f bind,cmd: accept Java API in bound packages
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.

Fixes golang/go#16876

Change-Id: I6951dd87235553ce09abe5117a39a503466163c0
Reviewed-on: https://go-review.googlesource.com/28597
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-09-22 10:16:33 +00:00
Elias Naur
61011ba584 bind: fix error type
Errors was recently converted to use objects as representation instead
of strings. Issue golang/go#17073 exposed a few places that wasn't properly
updated. Fix them and add the test case from the the issue.

Fixes golang/go#17073

Change-Id: I0191993a8427d930540716407fc09032f282fc66
Reviewed-on: https://go-review.googlesource.com/29176
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-09-16 13:52:19 +00:00
Elias Naur
e99a906c3a bind: avoid ObjC reserved names
The new tests in CL 28494 exposed a bug: the ObjC generator does
not avoid reserved names and names with special meaning ("init").
Generalize the name sanitizer from the Java generator and use that.

Also, move the lowerFirst function to gen.go since it is now used
by both generators.

Change-Id: I25b7af2594b2ea136f05d2bab1cfdc66ba169859
Reviewed-on: https://go-review.googlesource.com/28592
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-09-07 14:13:50 +00:00
Péter Szilágyi
2f75be449f bind: use lowercase method names for Java binds
There was a discussion a year ago about making methods and types
lowercase in ObjC (https://github.com/golang/go/issues/12889),
which was done (https://go-review.googlesource.com/#/c/15780/),
alas the suggested Java lower casing was never addressed.

This CL converts all generated Java methods to lower case.

Change-Id: Ia2f28519bc59362877881636109ddfc651b24960
Reviewed-on: https://go-review.googlesource.com/28494
Reviewed-by: Elias Naur <elias.naur@gmail.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-09-07 12:52:06 +00:00
Elias Naur
ed036a869f mobile/bind: fix comment
Change-Id: I100d1a32da7ec4f6b29f3590f23ca0a9ddbf230a
Reviewed-on: https://go-review.googlesource.com/27442
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Sebastien Binet <seb.binet@gmail.com>
2016-08-22 14:31:51 +00:00
Elias Naur
80e11ad074 mobile/bind: move generated Java classes to package level
Before this CL, generated Java classes or interfaces were inner
classes to the top package class. That is both unnecessary and creates
ugly class names. Instead, move every generated class and interface to its
own package level class.

NOTE: This is a backwards incompatible change and requires every client
of gomobile APIs to be updated to leave out the package class in the
type names. For example, the Go type

package pkg

type S struct {
}

now generates (with the default java package name go) a Java class named
go.pkg.S. The name before this CL was go.pkg.Pkg.S.

Also, change the custom java package to specify the package prefix and
not the full package as before. This is an unfortunate change needed
to avoid name clashes between two bound packages. On the plus side,
the change brings the custom package case closer to the default behaviour,
which is a commen prefix, "go.", and a distinct java package for every
Go package bound.

Change-Id: Iadfaad56e101d1caf7e2a05006f4d384859a20fe
Reviewed-on: https://go-review.googlesource.com/27436
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-08-22 07:41:35 +00:00
Elias Naur
44ce26ee94 mobile/bind: fix gomobile bind with custom Java package
The change from using strings to objects for passing errors across
the language barrier broke the custom java package mode of gombile
bind. Fix it and add a runtime test to make sure it won't happen
again.

Fixes golang/go#16262

Change-Id: Ia7f8afb79556798056f0755758052190081a2dbb
Reviewed-on: https://go-review.googlesource.com/24800
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-07-07 16:08:17 +00:00
Elias Naur
a3e0621280 mobile/bind: use objects to pass errors across the language barrier
Gobind uses strings for passing errors across the language barrier.
However, since Gobind doesn't have a concept of a nil string, it
can't separate an empty native string from a nil string.

In turn, that means that empty errors, exceptions or NSError * with
an empty description are treated as no error. With ObjC, empty errors
are replaced with a default string to workaround the issue, while
with Java empty errors are silently ignored.

Fix this by replacing strings with actual error objects, wrapping
the Go error, Java Throwable or ObjC NSError *, and letting the
existing bind machinery take care of passing the references across.

It's a large change for a small corner case, but I believe objects
are a better fit for exception that strings. Error objects also
naturally leads to future additions, for example accessing the
exception class name or chained exception.

Change-Id: Ie03b47cafcb231ad1e12a80195693fa7459c6265
Reviewed-on: https://go-review.googlesource.com/24100
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-06-23 18:55:48 +00:00
Elias Naur
e1840f9c11 mobile/bind: make Java proxy classes private
Proxies are an implementation detail, so make them private to hide
them from the public API.

Also, move the proxy classes out of its interface scope; classes
declared inside Java interfaces are always public and cannot be
declared otherwise. Use the lowercase "proxy" class prefix to
avoid name clashes with exported Go interfaces and structs.

Change-Id: Iae6a53ed4885b7899f2fa770b73c135f54ffb263
Reviewed-on: https://go-review.googlesource.com/21370
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-04-02 13:41:50 +00:00
Elias Naur
5e11c20fc0 mobile/bind: don't force Java classes to extend stub classes
Requiring user code to extend Go interface Stubs to be able to pass
Java objects to Go is clumsy and use up the single extend slot.
Instead, support (and enforce) java classes to implement translated
Go interface directly. This is similar to how ObjC works.

The stub classes are now gone, and users of gobind Java APIs need
to update their code to implement interfaces directly.

Change-Id: I880bb7c8e89d3c21210b2ab2c85ced8d7859ff48
Reviewed-on: https://go-review.googlesource.com/21313
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-03-31 07:59:45 +00:00
Elias Naur
5b96314b59 mobile/bind: implement interfaces from imported bound packages
Java classes must explicitly declare implemented interfaces. Bind
already declares all such interfaces within each package. Expand
the set of interfaces to include all bound packages.

In addition, let Java interfaces extend all possible interfaces in
the same way as Java classes. To avoid circular references, only
let interfaces extend compatible interfaces with fewer methods.

Before, each package was imported in its own importer, breaking the
assumption of types.AssignableTo that identical packages have
identical *types.Package. Fix that by using one importer for all
bound packages, replacing package path equality checks with direct
equality checks.

While we're here, add missing arguments to a few error messages.

Change-Id: I5eb58972a3abe918862ca99d5a203809699a3433
Reviewed-on: https://go-review.googlesource.com/20987
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-03-29 08:36:18 +00:00
Elias Naur
eb6cb84428 mobile/bind: ignore unbound types
If a method or function refers to a type from an unbound package,
ignore it instead of reporting an error.

Change-Id: I689da63c1a0d1a3aa09220311d871c1f6f66208f
Reviewed-on: https://go-review.googlesource.com/20985
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-03-21 23:28:22 +00:00
Elias Naur
390f7b3813 mobile/bind: skip unsupported functions, vars, fields and methods
Bind attempts to generate bindings for everything a package exports,
generating an error for what it cannot handle.
For multiple bound packages, unexporting what should not be bound
is sometimes awkward or outright impossible.

Lacking the equivalent of Cgo's //export directory, this CL change
the behaviour of bind to simply ignore everything it can't generate
bindings for, even if otherwise exported. For every declaration it
ignores, a comment is generated instead, to help any confusion as
to why a particular export was not included.

Change-Id: I2c7a5bee0f19a58009293b4e5ac2c95687e62e80
Reviewed-on: https://go-review.googlesource.com/20651
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-03-15 16:00:42 +00:00
Elias Naur
7d65c03f0a mobile/bind: only generate callable jmethodID declarations
Change-Id: I11b901be718d730f50fdc3877cbc2cf173aa6c66
Reviewed-on: https://go-review.googlesource.com/20658
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-03-14 13:44:20 +00:00
Elias Naur
1a0b242e59 mobile/bind: let Java toString call String method if available
Bind generates a default toString for Go structs. If the struct has
a String() string method, use that instead.

Change-Id: If83a6f5c9ad03abbd0b939b9120ff8dd2135f713
Reviewed-on: https://go-review.googlesource.com/20656
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-03-14 13:30:01 +00:00
Elias Naur
d841a034b5 mobile/bind: initialize imported bound packages
Make sure that a bound package's imported and also bound packages
are initialized before referencing methods and constructors in the
imported packages.

Change-Id: If158aac83c245a33695d3b1648d0dfc37a7313ac
Reviewed-on: https://go-review.googlesource.com/20652
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-03-13 18:10:58 +00:00
Elias Naur
462ddb163e mobile/bind: use the correct package for JNI type descriptors
Before, bind always used the currently bound package for all JNI type
descriptors. Now, the type's package is used, which is important
when referencing other bound packages.

Change-Id: If36a45785f7333072803f1e7a8ff28b39fa57d0f
Reviewed-on: https://go-review.googlesource.com/20650
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-03-13 18:10:01 +00:00
Elias Naur
7df33f4a5c mobile/bind: allow bound packages to refer to imported bound packages
Multiple packages are already supported, but only as if each packages
were bound in isolation. This CL lets a bound package refer to other
bound packages in its exported functions, types and fields.

In Java, the JNI class jclass and constructor jmethodID are exported
so other packages can construct proxies of other packages' interfaces.

In ObjC, the class @interface declarations are moved from the package
.m file to its .h file to allow other packages to constructs its
interface proxies.

Add a supporting test package, secondpkg, and add Java and ObjC tests
for the new cross package functionality. Also add simplepkg for
testing corner cases where the generated Go file must not include its
bound package.

While we're here, stop generating Go proxy types for struct types;
only Go interfaces can be implemented in the foreign language.

Change-Id: Icbfa739c893703867d38a9100ed0928fbd7a660d
Reviewed-on: https://go-review.googlesource.com/20575
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-03-12 06:23:01 +00:00
Elias Naur
ba0a725146 mobile/bind: avoid intermediate []rune copy converting Java string to Go
Converting a Go string to a string suitable use a specialized function,
UTF16Encode, that can encode the string directly to a malloc'ed buffer. That
way, only two copies are made when strings are passed from Go to Java; once
for UTF-8 to UTF-16 encoding and once for the creation of the Java String.

This CL implements the same optimization in the other direction, with a
UTF-16 to UTF-8 decoder implemented in C. Unfortunately, while calling into a
Go decoder also saves the extra copy, the Cgo overhead makes the calls much
slower for short strings.

To alleviate the risk of introducing decoding bugs, I've added the tests from
the encoding/utf16 package to SeqTest.

As a sideeffect, both Java and ObjC now always copy strings, regardless of
the argument mode. The cpy argument can therefore be removed from the string
conversion functions. Furthermore, the modeRetained and modeReturned modes
can be collapsed into just one.

While we're here, delete a leftover function from seq/strings.go that
wasn't removed when the old seq buffers went away.

Benchmarks, as compared with benchstat over 5 runs:

name                          old time/op  new time/op  delta
JavaStringShort               11.4µs ±13%  11.6µs ± 4%     ~     (p=0.859 n=10+5)
JavaStringShortDirect         19.5µs ± 9%  20.3µs ± 2%   +3.68%   (p=0.019 n=9+5)
JavaStringLong                 103µs ± 8%    24µs ± 4%  -77.13%   (p=0.001 n=9+5)
JavaStringLongDirect           113µs ± 9%    32µs ± 7%  -71.63%   (p=0.001 n=9+5)
JavaStringShortUnicode        11.1µs ±16%  10.7µs ± 5%     ~      (p=0.190 n=9+5)
JavaStringShortUnicodeDirect  19.6µs ± 7%  20.2µs ± 1%   +2.78%   (p=0.029 n=9+5)
JavaStringLongUnicode         97.1µs ± 9%  28.0µs ± 5%  -71.17%   (p=0.001 n=9+5)
JavaStringLongUnicodeDirect    105µs ±10%    34µs ± 5%  -67.23%   (p=0.002 n=8+5)
JavaStringRetShort            14.2µs ± 2%  13.9µs ± 1%   -2.15%   (p=0.006 n=8+5)
JavaStringRetShortDirect      20.8µs ± 2%  20.4µs ± 2%     ~      (p=0.065 n=8+5)
JavaStringRetLong             42.2µs ± 9%  42.4µs ± 3%     ~      (p=0.190 n=9+5)
JavaStringRetLongDirect       51.2µs ±21%  50.8µs ± 8%     ~      (p=0.518 n=9+5)
GoStringShort                 23.4µs ± 7%  22.5µs ± 3%   -3.55%   (p=0.019 n=9+5)
GoStringLong                  51.9µs ± 9%  53.1µs ± 3%     ~      (p=0.240 n=9+5)
GoStringShortUnicode          24.2µs ± 6%  22.8µs ± 1%   -5.54%   (p=0.002 n=9+5)
GoStringLongUnicode           58.6µs ± 8%  57.6µs ± 3%     ~      (p=0.518 n=9+5)
GoStringRetShort              27.6µs ± 1%  23.2µs ± 2%  -15.87%   (p=0.003 n=7+5)
GoStringRetLong                129µs ±12%    33µs ± 2%  -74.03%  (p=0.001 n=10+5)

Change-Id: Icb9481981493ffca8defed9fb80a9433d6048937
Reviewed-on: https://go-review.googlesource.com/20250
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-03-05 10:02:05 +00:00
Hyang-Ah Hana Kim
c2b8429cd1 bind: fallback to const.Value.String for pre go1.6
Fixes golang/go#14615

Change-Id: I75e130e5b7b2534660098907fa1f044390c01d01
Reviewed-on: https://go-review.googlesource.com/20164
Reviewed-by: Elias Naur <elias.naur@gmail.com>
2016-03-04 12:00:05 +00:00
Elias Naur
6fca37c69e mobile/bind: replace seq serialization with direct calls
The seq serialization machinery is a historic artifact from when Go
mobile code had to run in a separate process. Now that Go code is running
in-process, replace the explicit serialization with direct calls and pass
arguments on the stack.

The benefits are a much smaller bind runtime, much less garbage (and, in
Java, fewer objects with finalizers), less argument copying, and faster
cross-language calls.
The cost is a more complex generator, because some of the work from the
bind runtime is moved to generated code. Generated code now handles
conversion between Go and Java/ObjC types, multiple return values and memory
management of byte slice and string arguments.

To overcome the lack of calling C code between Go packages, all bound
packages now end up in the same (fake) package, "gomobile_bind", instead of
separate packages (go_<pkgname>). To avoid name clashes, the package name is
added as a prefix to generated functions and types.

Also, don't copy byte arrays passed to Go, saving call time and
allowing read([]byte)-style interfaces to foreign callers (#12113).

Finally, add support for nil interfaces and struct pointers to objc.

This is a large CL, but most of the changes stem from changing testdata.

The full benchcmp output on the CL/20095 benchmarks on my Nexus 5 is
reproduced below. Note that the savings for the JavaSlice* benchmarks are
skewed because byte slices are no longer copied before passing them to Go.

benchmark                                 old ns/op     new ns/op     delta
BenchmarkJavaEmpty                        26.0          19.0          -26.92%
BenchmarkJavaEmptyDirect                  23.0          22.0          -4.35%
BenchmarkJavaNoargs                       7685          2339          -69.56%
BenchmarkJavaNoargsDirect                 17405         8041          -53.80%
BenchmarkJavaOnearg                       26887         2366          -91.20%
BenchmarkJavaOneargDirect                 34266         7910          -76.92%
BenchmarkJavaOneret                       38325         2245          -94.14%
BenchmarkJavaOneretDirect                 46265         7708          -83.34%
BenchmarkJavaManyargs                     41720         2535          -93.92%
BenchmarkJavaManyargsDirect               51026         8373          -83.59%
BenchmarkJavaRefjava                      38139         21260         -44.26%
BenchmarkJavaRefjavaDirect                42706         28150         -34.08%
BenchmarkJavaRefgo                        34403         6843          -80.11%
BenchmarkJavaRefgoDirect                  40193         16582         -58.74%
BenchmarkJavaStringShort                  32366         9323          -71.20%
BenchmarkJavaStringShortDirect            41973         19118         -54.45%
BenchmarkJavaStringLong                   127879        94420         -26.16%
BenchmarkJavaStringLongDirect             133776        114760        -14.21%
BenchmarkJavaStringShortUnicode           32562         9221          -71.68%
BenchmarkJavaStringShortUnicodeDirect     41464         19094         -53.95%
BenchmarkJavaStringLongUnicode            131015        89401         -31.76%
BenchmarkJavaStringLongUnicodeDirect      134130        90786         -32.31%
BenchmarkJavaSliceShort                   42462         7538          -82.25%
BenchmarkJavaSliceShortDirect             52940         17017         -67.86%
BenchmarkJavaSliceLong                    138391        8466          -93.88%
BenchmarkJavaSliceLongDirect              205804        15666         -92.39%
BenchmarkGoEmpty                          3.00          3.00          +0.00%
BenchmarkGoEmptyDirect                    3.00          3.00          +0.00%
BenchmarkGoNoarg                          40342         13716         -66.00%
BenchmarkGoNoargDirect                    46691         13569         -70.94%
BenchmarkGoOnearg                         43529         13757         -68.40%
BenchmarkGoOneargDirect                   44867         14078         -68.62%
BenchmarkGoOneret                         45456         13559         -70.17%
BenchmarkGoOneretDirect                   44694         13442         -69.92%
BenchmarkGoRefjava                        55111         28071         -49.06%
BenchmarkGoRefjavaDirect                  60883         26872         -55.86%
BenchmarkGoRefgo                          57038         29223         -48.77%
BenchmarkGoRefgoDirect                    56153         27812         -50.47%
BenchmarkGoManyargs                       67967         17398         -74.40%
BenchmarkGoManyargsDirect                 60617         16998         -71.96%
BenchmarkGoStringShort                    57538         22600         -60.72%
BenchmarkGoStringShortDirect              52627         22704         -56.86%
BenchmarkGoStringLong                     128485        52530         -59.12%
BenchmarkGoStringLongDirect               138377        52079         -62.36%
BenchmarkGoStringShortUnicode             57062         22994         -59.70%
BenchmarkGoStringShortUnicodeDirect       62563         22938         -63.34%
BenchmarkGoStringLongUnicode              139913        55553         -60.29%
BenchmarkGoStringLongUnicodeDirect        150863        57791         -61.69%
BenchmarkGoSliceShort                     59279         20215         -65.90%
BenchmarkGoSliceShortDirect               60160         21136         -64.87%
BenchmarkGoSliceLong                      411225        301870        -26.59%
BenchmarkGoSliceLongDirect                399029        298915        -25.09%

Fixes golang/go#12619
Fixes golang/go#12113
Fixes golang/go#13033

Change-Id: I2b45e9e98a1248e3c23a5137f775f7364908bec7
Reviewed-on: https://go-review.googlesource.com/19821
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-03-03 15:03:45 +00:00
Elias Naur
c432672682 mobile/bind: fix long strings
Change-Id: Ia7c4523804b2588efb3ea6cc14b34a951faa298c
Reviewed-on: https://go-review.googlesource.com/20092
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-03-01 16:03:40 +00:00
Elias Naur
7538792349 mobile/bind: translate implicit Go interface implementations to Java
To implement an interface in Java the interface type must be listed
in the class declaration. Emulate the implicit Go interface
implementations in Java by listing all possible (non-empty) interfaces.

For example, given

type (
    S struct{}
    I  interface {
        M()
    }
)

func (s *S) M() {
}

in Go, the Java class S will be declared to implement the Java
interface I.

Fixes a TODO.

Change-Id: I5b0d2dd65938004ab29029f481cace4b8fb4b26f
Reviewed-on: https://go-review.googlesource.com/19417
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-02-11 21:46:02 +00:00
David Crawshaw
ab6091a309 bind: do not generate unused Seq objects
Updates golang/go#12619

Change-Id: Ie851795580c82ade3ee70bdb3945b23ca72f57e0
Reviewed-on: https://go-review.googlesource.com/17866
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2016-01-11 18:08:22 +00:00
Hyang-Ah Hana Kim
0a581ceb1e bind/java: do not return null String for empty Go string
Fixes golang/go#13430

Change-Id: Ic018761af6a40f6b04ec4449110f54af8f543a53
Reviewed-on: https://go-review.googlesource.com/17273
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-12-01 20:12:01 +00:00
David Crawshaw
e2a9091da2 bind: remove extra "package" from error string
Fixes golang/go#13064

Change-Id: I2cde12a831607cd37d9760d92c0ef0f53fd6dd8b
Reviewed-on: https://go-review.googlesource.com/16351
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2015-11-13 12:13:51 +00:00
Hyang-Ah (Hana) Kim
bb506cefe4 bind: error for packages with no exported names.
For error message improvement mentioned in golang/go#12842

Change-Id: I066ae9dc9415b34bf93128098199bbb935b7dedc
Reviewed-on: https://go-review.googlesource.com/15410
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-10-07 20:50:02 +00:00
Hyang-Ah (Hana) Kim
45ed283c80 bind: support exported variables
basic types, struct*, interface.

TODO: error, non-pointer struct, pointer basic types, slice of bytes.

Update golang/go#12475.

Change-Id: I5ff91059b1f963b0cadb6f76cb0e12f7b6b98718
Reviewed-on: https://go-review.googlesource.com/15340
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-10-07 20:48:45 +00:00
Hyang-Ah (Hana) Kim
60728759f9 bind: add const type support
Update golang/go#12475

Change-Id: I7fdc22462b5925c84ebbeb54517032c2fbd0545b
Reviewed-on: https://go-review.googlesource.com/15120
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-09-30 20:56:48 +00:00
Meir Fischer
00865a642f bind: improve readability for float default values
To improve readability for default numeric types
represented as strings, use 0.0 for floating point types.
(No tests make use of this change so golden update
not necessary; not significant enough for new test/test mod.)
Fix spelling on error statement; this was the only
instance of that spelling error in the repository.

Change-Id: I373890725b33da11c6780ba93674d89541bf758c
Reviewed-on: https://go-review.googlesource.com/13645
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2015-09-01 18:16:37 +00:00
Hyang-Ah (Hana) Kim
c384607ef3 bind: support for custom java package name and objective-c prefix.
Introduce options -javapkg and -prefix for gobind command.

The following generates java class Testpkg with package name com.example.

gobind -lang=java -javapkg=com.example testpkg

The following generates objective-c files where function and type names
are prefixed with ExampleTestpkg.

gobind -lang=objc -prefix=Example testpkg

As discussed in golang/go#9660 and golang/go#12245.

Gomobile support is not yet implemented.

Change-Id: Ib9e39997ce915580a5a2e25643c0c28373f27ee1
Reviewed-on: https://go-review.googlesource.com/13969
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-08-28 13:57:06 +00:00
David Crawshaw
4628c38e0f bind: handle unimplementable interfaces
Fixes golang/go#12330

Change-Id: I1568d04b7e48242105a7028ca471e2138f684eeb
Reviewed-on: https://go-review.googlesource.com/13946
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2015-08-27 21:36:14 +00:00
David Crawshaw
11fe695b54 bind: support fields with type error
Fixes golang/go#12328

Change-Id: I42872d26acb1c44522a64405cfa2d0f10fb24485
Reviewed-on: https://go-review.googlesource.com/13919
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2015-08-26 20:25:55 +00:00
David Crawshaw
48bd7cbbc7 bind: adjust invalid java package names
Updates golang/go#12273

Change-Id: I8eac3e84d5a473e9ffe45705cea88537573aef61
Reviewed-on: https://go-review.googlesource.com/13873
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2015-08-24 21:08:09 +00:00