code review 9643044: cmd/cgo: use intgo, not int, for string and slice structures

cmd/cgo: use intgo, not int, for string and slice structures

Fixes issue 5548.

[iant, 2013-05-23 18:19:42]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://go.googlecode.com/hg/

[minux1, 2013-05-23 18:41:36]

i was thinking about the same clobber stack for tests, but
my version couldn't reliably reproduce the test failure.

the test code looks good to me.

i have a few questions about cmd/cgo/out.go.

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go
File src/cmd/cgo/out.go (left):

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go#oldcode940
src/cmd/cgo/out.go:940: return &Type{Size: p.PtrSize + 8, Align: p.PtrSize, C:
c("GoSlice")}
i think we should also change Size to p.PtrSize * 3.

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go
File src/cmd/cgo/out.go (right):

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go#newcode977
src/cmd/cgo/out.go:977: // The string data is 1 pointer + 1 int, but this always
please update this comment.

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go#newcode1035
src/cmd/cgo/out.go:1035: typedef long long intgo;
on LP64 systems, seems long suffices for 64-bit int.
am i missing something?

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go#newcode1037
src/cmd/cgo/out.go:1037: typedef int intgo;
why use int (instead of long) for intgo here?

[iant, 2013-05-23 19:23:06]

Thanks for the comments.

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go
File src/cmd/cgo/out.go (left):

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go#oldcode940
src/cmd/cgo/out.go:940: return &Type{Size: p.PtrSize + 8, Align: p.PtrSize, C:
c("GoSlice")}
On 2013/05/23 18:41:36, minux wrote:
> i think we should also change Size to p.PtrSize * 3.

Done.

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go
File src/cmd/cgo/out.go (right):

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go#newcode977
src/cmd/cgo/out.go:977: // The string data is 1 pointer + 1 int, but this always
On 2013/05/23 18:41:36, minux wrote:
> please update this comment.

Done.

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go#newcode1035
src/cmd/cgo/out.go:1035: typedef long long intgo;
On 2013/05/23 18:41:36, minux wrote:
> on LP64 systems, seems long suffices for 64-bit int.
> am i missing something?

You aren't missing anything.  I just want to match the code in gccProlog here,
since gccProlog verifies that "long long" is exactly 64 bits.

https://codereview.appspot.com/9643044/diff/1/src/cmd/cgo/out.go#newcode1037
src/cmd/cgo/out.go:1037: typedef int intgo;
On 2013/05/23 18:41:36, minux wrote:
> why use int (instead of long) for intgo here?

Again because gccProlog verifies that int is 32 bits.

[minux1, 2013-05-23 19:24:40]

LGTM.

[iant, 2013-05-24 05:51:15]

*** Submitted as https://code.google.com/p/go/source/detail?r=fa6f9cac3256 ***

cmd/cgo: use intgo, not int, for string and slice structures

Fixes issue 5548.

R=golang-dev, minux.ma
CC=golang-dev
https://codereview.appspot.com/9643044