x/mobile: NSData* generated code compilation fails

[tadovas]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version go1.9.2 darwin/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/tadovas/work/go/openvpnv3-go-bindings"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.9.2/libexec"
GOTOOLDIR="/usr/local/Cellar/go/1.9.2/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/_j/73ymsvw56v989xyfwn6q18_m0000gn/T/go-build788123186=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"

What did you do?

Binding call to any iOS function which accepts NSData* as parameter

What did you expect to see?

Successfully binding and build.

What did you see instead?

gobind
/var/folders/_j/73ymsvw56v989xyfwn6q18_m0000gn/T/gomobile-work-516612884/src/gobind/interfaces_darwin.go:51: cannot use 0 (type int) as type bool in argument to fromSlice

It seems that https://github.com/golang/mobile/blob/master/bind/objc/seq_darwin.go.support#L60 function fromSlice expects second parameter as boolean, but https://github.com/golang/mobile/blob/master/bind/genobjcw.go#L476 generates fromSlice call and passes 0 as second argument instead.
The same is with toSlice function and code generation.

Am I missing something here?

[tadovas]

Created a PR anyway.

[gopherbot]

Change https://golang.org/cl/135423 mentions this issue: bind: pass correct arguments to fromSlice and toSlice