imports: don't look for, or find, empty packages
Fix a pair of bugs that combined to cause golang/go#29520. First, don't go
looking for a package if we've only seen unexported identifiers selected
from it. It's probably a typo. Second, don't find packages with no files
in them, e.g. because they're all build tagged out. We can't know what
package they form, so we have no business considering them.
Test only for the first, since without the first bug the second has no
observable effect on behavior, and I don't want to test the private API.
Fixes golang/go#29520
Change-Id: I5b797940bec051be5945b9c5cb4e7bf28527a939
Reviewed-on: https://go-review.googlesource.com/c/156178
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/imports/fix.go b/imports/fix.go
index 6912409..1565f92 100644
--- a/imports/fix.go
+++ b/imports/fix.go
@@ -157,7 +157,11 @@
break
}
if xident.Obj != nil {
- // if the parser can resolve it, it's not a package ref
+ // If the parser can resolve it, it's not a package ref.
+ break
+ }
+ if !ast.IsExported(v.Sel.Name) {
+ // Whatever this is, it's not exported from a package.
break
}
pkgName := xident.Name
@@ -166,9 +170,7 @@
r = make(map[string]bool)
refs[pkgName] = r
}
- if ast.IsExported(v.Sel.Name) {
- r[v.Sel.Name] = true
- }
+ r[v.Sel.Name] = true
}
return visitor
}
@@ -855,10 +857,7 @@
for _, fname := range pkg.goPackage.CompiledGoFiles {
f, err := parser.ParseFile(fset, fname, nil, 0)
if err != nil {
- if Debug {
- log.Printf("Parsing %s: %v", fname, err)
- }
- return nil, err
+ return nil, fmt.Errorf("parsing %s: %v", fname, err)
}
for name := range f.Scope.Objects {
if ast.IsExported(name) {
@@ -871,34 +870,29 @@
exports := make(map[string]bool)
- buildCtx := build.Default
-
- // ReadDir is like ioutil.ReadDir, but only returns *.go files
- // and filters out _test.go files since they're not relevant
- // and only slow things down.
- buildCtx.ReadDir = func(dir string) (notTests []os.FileInfo, err error) {
- all, err := ioutil.ReadDir(dir)
- if err != nil {
- return nil, err
+ // Look for non-test, buildable .go files which could provide exports.
+ all, err := ioutil.ReadDir(pkg.dir)
+ if err != nil {
+ return nil, err
+ }
+ var files []os.FileInfo
+ for _, fi := range all {
+ name := fi.Name()
+ if !strings.HasSuffix(name, ".go") || strings.HasSuffix(name, "_test.go") {
+ continue
}
- notTests = all[:0]
- for _, fi := range all {
- name := fi.Name()
- if strings.HasSuffix(name, ".go") && !strings.HasSuffix(name, "_test.go") {
- notTests = append(notTests, fi)
- }
+ match, err := build.Default.MatchFile(pkg.dir, fi.Name())
+ if err != nil || !match {
+ continue
}
- return notTests, nil
+ files = append(files, fi)
}
- files, err := buildCtx.ReadDir(pkg.dir)
- if err != nil {
- log.Print(err)
- return nil, err
+ if len(files) == 0 {
+ return nil, fmt.Errorf("dir %v contains no buildable, non-test .go files", pkg.dir)
}
fset := token.NewFileSet()
-
for _, fi := range files {
select {
case <-ctx.Done():
@@ -906,30 +900,19 @@
default:
}
- match, err := buildCtx.MatchFile(pkg.dir, fi.Name())
- if err != nil || !match {
- continue
- }
fullFile := filepath.Join(pkg.dir, fi.Name())
f, err := parser.ParseFile(fset, fullFile, nil, 0)
if err != nil {
- if Debug {
- log.Printf("Parsing %s: %v", fullFile, err)
- }
- return nil, err
+ return nil, fmt.Errorf("parsing %s: %v", fullFile, err)
}
pkgName := f.Name.Name
if pkgName == "documentation" {
// Special case from go/build.ImportDir, not
- // handled by buildCtx.MatchFile.
+ // handled by MatchFile above.
continue
}
if pkgName != expectPackage {
- err := fmt.Errorf("scan of dir %v is not expected package %v (actually %v)", pkg.dir, expectPackage, pkgName)
- if Debug {
- log.Print(err)
- }
- return nil, err
+ return nil, fmt.Errorf("scan of dir %v is not expected package %v (actually %v)", pkg.dir, expectPackage, pkgName)
}
for name := range f.Scope.Objects {
if ast.IsExported(name) {
@@ -1015,6 +998,9 @@
exports, err := loadExports(ctx, pkgName, c.pkg)
if err != nil {
+ if Debug {
+ log.Printf("loading exports in dir %s (seeking package %s): %v", c.pkg.dir, pkgName, err)
+ }
resc <- nil
return
}
diff --git a/imports/fix_test.go b/imports/fix_test.go
index ef80384..1006e62 100644
--- a/imports/fix_test.go
+++ b/imports/fix_test.go
@@ -752,6 +752,16 @@
`,
},
+ {
+ name: "ignore_unexported_identifier",
+ in: `package main
+var _ = fmt.unexported`,
+ out: `package main
+
+var _ = fmt.unexported
+`,
+ },
+
// FormatOnly
{
name: "formatonly_works",
