code review 7393052: cmd/vet: restructure to be package-driven

cmd/vet: restructure to be package-driven
This is a simple refactoring of main.go that will enable the type checker
to be used during vetting.
The change has an unimportant effect on the arguments: it now assumes
that all files named explicitly on the command line belong to the same
package. When run by the go command, this was true already.

Also restore a missing parenthesis from an error message.

[r, 2013-02-22 20:49:23]

Hello golang-dev@googlegroups.com,

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

[gri, 2013-02-22 21:03:34]

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go
File src/cmd/vet/main.go (right):

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode59
src/cmd/vet/main.go:59: fmt.Fprintf(os.Stderr, "\tvet [flags] directory...\n")
# Must contain a single package
?

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode140
src/cmd/vet/main.go:140: if strings.Contains(err.Error(), "no Go source files")
{
if _, nogo := err.(*build.NoGoError); nogo {
   return
}

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode151
src/cmd/vet/main.go:151: names[i] = directory + "/" + name
pathutil.Join ?

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode163
src/cmd/vet/main.go:163: f, err := os.Open(name)
you can just call parser.ParseFile(fs, name, nil, 0)

(nil src) and it will open the file for you

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode197
src/cmd/vet/main.go:197: fmt.Fprintf(os.Stderr, "USE DIR ONLY: %s\n", name)
residue?

[bradfitz, 2013-02-22 21:03:41]

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go
File src/cmd/vet/main.go (right):

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode116
src/cmd/vet/main.go:116: if fi, err := os.Stat(name); err == nil && fi.IsDir() {
so the ENOENT case is a file?

I'd bail here instead if err != nil.

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode151
src/cmd/vet/main.go:151: names[i] = directory + "/" + name
filepath.Join?

[r, 2013-02-22 21:15:39]

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go
File src/cmd/vet/main.go (right):

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode59
src/cmd/vet/main.go:59: fmt.Fprintf(os.Stderr, "\tvet [flags] directory...\n")
not true. it is walked recursively so there can be many packages. i think it's
ok as is.

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode116
src/cmd/vet/main.go:116: if fi, err := os.Stat(name); err == nil && fi.IsDir() {
On 2013/02/22 21:03:41, bradfitz wrote:
> so the ENOENT case is a file?
> 
> I'd bail here instead if err != nil.

Done.

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode140
src/cmd/vet/main.go:140: if strings.Contains(err.Error(), "no Go source files")
{
On 2013/02/22 21:03:34, gri wrote:
> if _, nogo := err.(*build.NoGoError); nogo {
>    return
> }

Done.

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode151
src/cmd/vet/main.go:151: names[i] = directory + "/" + name
On 2013/02/22 21:03:41, bradfitz wrote:
> filepath.Join?

Done.

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode151
src/cmd/vet/main.go:151: names[i] = directory + "/" + name
On 2013/02/22 21:03:34, gri wrote:
> pathutil.Join ?
filepath.Join

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode163
src/cmd/vet/main.go:163: f, err := os.Open(name)
but i need the raw data to check build tags anyway.

https://codereview.appspot.com/7393052/diff/1/src/cmd/vet/main.go#newcode197
src/cmd/vet/main.go:197: fmt.Fprintf(os.Stderr, "USE DIR ONLY: %s\n", name)
On 2013/02/22 21:03:34, gri wrote:
> residue?

Done.

[r, 2013-02-22 21:15:49]

Hello golang-dev@googlegroups.com, gri@golang.org, bradfitz@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[gri, 2013-02-22 21:29:18]

LGTM

https://codereview.appspot.com/7393052/diff/4002/src/cmd/vet/main.go
File src/cmd/vet/main.go (right):

https://codereview.appspot.com/7393052/diff/4002/src/cmd/vet/main.go#newcode58
src/cmd/vet/main.go:58: fmt.Fprintf(os.Stderr, "\tvet [flags] directory...\n")
i meant

# Each directory must contain a single package

but perhaps that's obvious

[r, 2013-02-22 21:32:48]

*** Submitted as https://code.google.com/p/go/source/detail?r=e82360e6c916 ***

cmd/vet: restructure to be package-driven
This is a simple refactoring of main.go that will enable the type checker
to be used during vetting.
The change has an unimportant effect on the arguments: it now assumes
that all files named explicitly on the command line belong to the same
package. When run by the go command, this was true already.

Also restore a missing parenthesis from an error message.

R=golang-dev, gri, bradfitz
CC=golang-dev
https://codereview.appspot.com/7393052