cmd/go: respect system CGO_CFLAGS and CGO_CXXFLAGS

cmd/go: respect system CGO_CFLAGS and CGO_CXXFLAGS

Fixes issue 6882.

[atom, 2014-03-09 07:28:38]

https://codereview.appspot.com/72820045/diff/20001/src/cmd/go/build.go
File src/cmd/go/build.go (right):

https://codereview.appspot.com/72820045/diff/20001/src/cmd/go/build.go#newcod...
src/cmd/go/build.go:2167: if err := b.run(p.Dir, p.ImportPath, cgoenv, cgoExe,
"-objdir", obj, cgoflags, "--", cgoCPPFLAGS, cgoCFLAGS, p.CgoFiles); err != nil
{
This line fails also with go1.2.1 if CGO_CFLAGS is set in the environment. The
line was expecting cgoCFLAGS to be an empty list.

We could simply delete cgoCFLAGS from the list of arguments here. This will
maintain the behavior of go1.2.1.

[iant, 2014-03-09 16:36:55]

On Sat, Mar 8, 2014 at 11:28 PM,  <0xE2.0x9A.0x9B@gmail.com> wrote:
>
> https://codereview.appspot.com/72820045/diff/20001/src/cmd/go/build.go
> File src/cmd/go/build.go (right):
>
>
https://codereview.appspot.com/72820045/diff/20001/src/cmd/go/build.go#newcod...
> src/cmd/go/build.go:2167: if err := b.run(p.Dir, p.ImportPath, cgoenv,
> cgoExe, "-objdir", obj, cgoflags, "--", cgoCPPFLAGS, cgoCFLAGS,
> p.CgoFiles); err != nil {
> This line fails also with go1.2.1 if CGO_CFLAGS is set in the
> environment. The line was expecting cgoCFLAGS to be an empty list.
>
> We could simply delete cgoCFLAGS from the list of arguments here. This
> will maintain the behavior of go1.2.1.

Deleting cgoCFLAGS can't be right, since that would ignore any #pragma
cgo CFLAGS that might be providing, for example, required -I options.
I guess in this case we have to not add the default -g -O2.  Or we
have to fix cgo work when -O2 is provided.

Does your CL have the same issue?

Ian

[atom, 2014-03-09 17:41:12]

On 2014/03/09 16:36:55, iant wrote:
> On Sat, Mar 8, 2014 at 11:28 PM,  <mailto:0xE2.0x9A.0x9B@gmail.com> wrote:
> >
> > https://codereview.appspot.com/72820045/diff/20001/src/cmd/go/build.go
> > File src/cmd/go/build.go (right):
> >
> >
>
https://codereview.appspot.com/72820045/diff/20001/src/cmd/go/build.go#newcod...
> > src/cmd/go/build.go:2167: if err := b.run(p.Dir, p.ImportPath, cgoenv,
> > cgoExe, "-objdir", obj, cgoflags, "--", cgoCPPFLAGS, cgoCFLAGS,
> > p.CgoFiles); err != nil {
> > This line fails also with go1.2.1 if CGO_CFLAGS is set in the
> > environment. The line was expecting cgoCFLAGS to be an empty list.
> >
> > We could simply delete cgoCFLAGS from the list of arguments here. This
> > will maintain the behavior of go1.2.1.
> 
> Deleting cgoCFLAGS can't be right, since that would ignore any #pragma
> cgo CFLAGS that might be providing, for example, required -I options.
> I guess in this case we have to not add the default -g -O2.  Or we
> have to fix cgo work when -O2 is provided.
>
> Does your CL have the same issue?

Yes.

[iant, 2014-03-12 01:45:50]

*** Abandoned ***