protogen: drop dependency on golang.org/x/tools/go/ast/astutil
To keep the dependency tree of Go protobufs as small as possible,
avoid depending on astutil. Most of the complexity of astutil.AddNamedImport
was for identifying an existing import block to insert imports into,
which is not relevant for our use-case.
Assuming that we always create a new import block after the package
statement, the logic for doing the AST manipulation is relatively simple.
This re-write properly handles an inline comment after the
package statement, which astutil.AddNamedImport (see golang.org/issue/30724)
currently fails to do.
Change-Id: I894e733aa82a241719b6f0c23de8d2fbfb67b778
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/166522
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/protogen/protogen.go b/protogen/protogen.go
index a61baa0..cf1e809 100644
--- a/protogen/protogen.go
+++ b/protogen/protogen.go
@@ -34,7 +34,6 @@
"github.com/golang/protobuf/v2/reflect/protodesc"
"github.com/golang/protobuf/v2/reflect/protoreflect"
"github.com/golang/protobuf/v2/reflect/protoregistry"
- "golang.org/x/tools/go/ast/astutil"
descriptorpb "github.com/golang/protobuf/v2/types/descriptor"
pluginpb "github.com/golang/protobuf/v2/types/plugin"
@@ -973,28 +972,66 @@
return nil, fmt.Errorf("%v: unparsable Go source: %v\n%v", g.filename, err, src.String())
}
- // Add imports.
- var importPaths []string
- for importPath := range g.packageNames {
- importPaths = append(importPaths, string(importPath))
- }
- sort.Strings(importPaths)
+ // Collect a sorted list of all imports.
+ var importPaths [][2]string
rewriteImport := func(importPath string) string {
if f := g.gen.opts.ImportRewriteFunc; f != nil {
return string(f(GoImportPath(importPath)))
}
return importPath
}
- for _, importPath := range importPaths {
- astutil.AddNamedImport(fset, file, string(g.packageNames[GoImportPath(importPath)]), rewriteImport(importPath))
+ for importPath := range g.packageNames {
+ pkgName := string(g.packageNames[GoImportPath(importPath)])
+ pkgPath := rewriteImport(string(importPath))
+ importPaths = append(importPaths, [2]string{pkgName, pkgPath})
}
for importPath := range g.manualImports {
- if _, ok := g.packageNames[importPath]; ok {
- continue
+ if _, ok := g.packageNames[importPath]; !ok {
+ pkgPath := rewriteImport(string(importPath))
+ importPaths = append(importPaths, [2]string{"_", pkgPath})
}
- astutil.AddNamedImport(fset, file, "_", rewriteImport(string(importPath)))
}
- ast.SortImports(fset, file)
+ sort.Slice(importPaths, func(i, j int) bool {
+ return importPaths[i][1] < importPaths[j][1]
+ })
+
+ // Modify the AST to include a new import block.
+ if len(importPaths) > 0 {
+ // Insert block after package statement or
+ // possible comment attached to the end of the package statement.
+ pos := file.Package
+ tokFile := fset.File(file.Package)
+ pkgLine := tokFile.Line(file.Package)
+ for _, c := range file.Comments {
+ if tokFile.Line(c.Pos()) > pkgLine {
+ break
+ }
+ pos = c.End()
+ }
+
+ // Construct the import block.
+ impDecl := &ast.GenDecl{
+ Tok: token.IMPORT,
+ TokPos: pos,
+ Lparen: pos,
+ Rparen: pos,
+ }
+ for _, importPath := range importPaths {
+ impDecl.Specs = append(impDecl.Specs, &ast.ImportSpec{
+ Name: &ast.Ident{
+ Name: importPath[0],
+ NamePos: pos,
+ },
+ Path: &ast.BasicLit{
+ Kind: token.STRING,
+ Value: strconv.Quote(importPath[1]),
+ ValuePos: pos,
+ },
+ EndPos: pos,
+ })
+ }
+ file.Decls = append([]ast.Decl{impDecl}, file.Decls...)
+ }
var out bytes.Buffer
if err = (&printer.Config{Mode: printer.TabIndent | printer.UseSpaces, Tabwidth: 8}).Fprint(&out, fset, file); err != nil {