code review 217620043: libgo: Build and install

libgo: Build and install libnetgo.a

libnetgo.a provides the net
package built with the netgo
tag enabled.  This provides the
netgo fallback solution for gccgo.
This lib must be explicitly linked
in using the -gccgoflags, so is
not included by default.

Fixes gcc BZ 63731.

[laboger, 2015-04-01 14:11:15]

Hello gofrontend-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/gofrontend

[iant, 2015-04-03 18:20:10]

Please fix the first line of the description to be on a single line.

Any thoughts on where this should be documented?

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am
File libgo/Makefile.am (left):

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am#oldcode1
libgo/Makefile.am:1: # Makefile.am -- Go library Makefile.
Why remove this line?

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am
File libgo/Makefile.am (right):

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am#newcode823
libgo/Makefile.am:823: go_netgo_files = \
Rather than duplicating the list entirely, let's make another variable that
holds all the common files, and use that variable in both go_net_files and
go_netgo_files.

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am#newcode...
libgo/Makefile.am:2104: $(LTGOCOMPILE) -I . -c -fgo-pkgpath=net -o $@ $$files
If you are using LTGOCOMPILE you should be generating a .lo file, not a .o file.
 In this case, since you aren't creating a shared library, it should be fine to
generate a .o file and use $(GOCOMPILE).

[laboger, 2015-04-07 13:12:32]

As far as documentation, I tried to find some documentation on build 
tags in general and netgo specifically because it seems like this should 
be documented there, but did not find much.  Here are some ideas:
- add something to the 'go help build' output about the use of the netgo 
tag in general and how it would be used to work around the static 
linking  warning/problem against libnss and the workarounds for gc and gccgo
- if there is something somewhere else that describes the netgo tag and 
when to use it, then add something about how to achieve the same effect 
in gccgo
- seems like it would be good to have documentation describing the 
differences in using gccgo vs. gc and this would be included in that, 
however that is a bigger work item and would require more thought on 
what to include in such a document.

I'll work on the other changes.

On 04/03/2015 01:20 PM, iant@golang.org wrote:
> Please fix the first line of the description to be on a single line.
>
> Any thoughts on where this should be documented?
>
>
> https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am
> File libgo/Makefile.am (left):
>
> https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am#oldcode1

>
> libgo/Makefile.am:1: # Makefile.am -- Go library Makefile.
> Why remove this line?
>
> https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am
> File libgo/Makefile.am (right):
>
>
https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am#newcode823

>
> libgo/Makefile.am:823: go_netgo_files = \
> Rather than duplicating the list entirely, let's make another variable
> that holds all the common files, and use that variable in both
> go_net_files and go_netgo_files.
>
>
https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am#newcode...

>
> libgo/Makefile.am:2104: $(LTGOCOMPILE) -I . -c -fgo-pkgpath=net -o $@
> $$files
> If you are using LTGOCOMPILE you should be generating a .lo file, not a
> .o file.  In this case, since you aren't creating a shared library, it
> should be fine to generate a .o file and use $(GOCOMPILE).
>
> https://codereview.appspot.com/217620043/
>
>
>

[laboger, 2015-04-07 15:53:47]

Please review changes.

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am
File libgo/Makefile.am (left):

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am#oldcode1
libgo/Makefile.am:1: # Makefile.am -- Go library Makefile.
On 2015/04/03 18:20:10, iant wrote:
> Why remove this line?

Sorry shouldn't have been.

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am
File libgo/Makefile.am (right):

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am#newcode823
libgo/Makefile.am:823: go_netgo_files = \
On 2015/04/03 18:20:10, iant wrote:
> Rather than duplicating the list entirely, let's make another variable that
> holds all the common files, and use that variable in both go_net_files and
> go_netgo_files.

Good idea.  Done.

https://codereview.appspot.com/217620043/diff/40001/libgo/Makefile.am#newcode...
libgo/Makefile.am:2104: $(LTGOCOMPILE) -I . -c -fgo-pkgpath=net -o $@ $$files
On 2015/04/03 18:20:10, iant wrote:
> If you are using LTGOCOMPILE you should be generating a .lo file, not a .o
file.
>  In this case, since you aren't creating a shared library, it should be fine
to
> generate a .o file and use $(GOCOMPILE).

Tried this multiple ways and forgot to change this.  Fixed.

[iant, 2015-04-07 18:05:38]

LGTM

[iant, 2015-04-07 18:08:44]

*** Submitted as
https://code.google.com/p/gofrontend/source/detail?r=46a450318709 ***

libgo: Build and install libnetgo.a

libnetgo.a provides the net
package built with the netgo
tag enabled.  This provides the
netgo fallback solution for gccgo.
This lib must be explicitly linked
in using the -gccgoflags, so is
not included by default.

Fixes gcc BZ 63731.

LGTM=iant
R=gofrontend-dev, iant
CC=gofrontend-dev
https://codereview.appspot.com/217620043

Committer: Ian Lance Taylor <iant@golang.org>