go/printer: revert "do not treat comments inside a ast.Decl as godoc"

This reverts commit CL 609077.

Reason for revert: it turned out to also introduce a change to the
formatting as described in issue #69382, which wasn't intended.

For #69382.

Change-Id: Id8f36e5503e63e7586c8afe7c7d3dc25fd56ed94
Reviewed-on: https://go-review.googlesource.com/c/go/+/612137
Reviewed-by: Christian Höppner <hoeppi@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

src/go/printer/nodes.go

@@ -1737,9 +1737,6 @@ func (p *printer) genDecl(d *ast.GenDecl) {
 	p.setPos(d.Pos())
 	p.print(d.Tok, blank)
 
-	defer func(d bool) { p.inDecl = d }(p.inDecl)
-	p.inDecl = true
-
 	if d.Lparen.IsValid() || len(d.Specs) != 1 {
 		// group of parenthesized declarations
 		p.setPos(d.Lparen)
@@ -1924,10 +1921,6 @@ func (p *printer) funcDecl(d *ast.FuncDecl) {
 	p.setComment(d.Doc)
 	p.setPos(d.Pos())
 	p.print(token.FUNC, blank)
-
-	defer func(d bool) { p.inDecl = d }(p.inDecl)
-	p.inDecl = true
-
 	// We have to save startCol only after emitting FUNC; otherwise it can be on a
 	// different line (all whitespace preceding the FUNC is emitted only when the
 	// FUNC is emitted).

src/go/printer/printer.go

@@ -63,7 +63,6 @@ type printer struct {
 	mode         pmode        // current printer mode
 	endAlignment bool         // if set, terminate alignment immediately
 	impliedSemi  bool         // if set, a linebreak implies a semicolon
-	inDecl       bool         // if set, printer is inside declaration (after first token)
 	lastTok      token.Token  // last token printed (token.ILLEGAL if it's whitespace)
 	prevOpen     token.Token  // previous non-brace "open" token (, [, or token.ILLEGAL
 	wsbuf        []whiteSpace // delayed white space
@@ -740,9 +739,8 @@ func (p *printer) intersperseComments(next token.Position, tok token.Token) (wro
 	for p.commentBefore(next) {
 		list := p.comment.List
 		changed := false
-		if !p.inDecl &&
+		if p.lastTok != token.IMPORT && // do not rewrite cgo's import "C" comments
-			p.lastTok != token.IMPORT && // do not rewrite cgo's import "C" comments
+			p.posFor(p.comment.Pos()).Column == 1 &&
-			p.posFor(p.comment.Pos()).Line != p.last.Line &&
 			p.posFor(p.comment.End()+1) == next {
 			// Unindented comment abutting next token position:
 			// a top-level doc comment.

src/go/printer/printer_test.go

@@ -16,7 +16,6 @@ import (
 	"io"
 	"os"
 	"path/filepath"
-	"strings"
 	"testing"
 	"time"
 )
@@ -864,192 +863,3 @@ func TestEmptyDecl(t *testing.T) { // issue 63566
 		}
 	}
 }
-
-func TestDocFormat(t *testing.T) {
-	cases := []struct {
-		src  string
-		want string
-	}{
-		{
-			src: `package main
-
-func main() {
-//
-//go:directive
-// test
-//
-}
-`,
-			want: `package main
-
-func main() {
-	//
-	//go:directive
-	// test
-	//
-}
-`,
-		},
-		{
-			src: `package main
-
-func main() {
-	//go:directive
-	// test
-	type a struct{}
-
-//go:directive
-// test
-test()
-}
-`,
-			want: `package main
-
-func main() {
-	//go:directive
-	// test
-	type a struct{}
-
-	//go:directive
-	// test
-	test()
-}
-`,
-		},
-		{
-			src: `package main
-
-func main() {
-//go:directive
-// test
-type a struct{}
-}
-`,
-			want: `package main
-
-func main() {
-	//go:directive
-	// test
-	type a struct{}
-}
-`,
-		},
-		{
-			src: `package main
-
-func a() {
-//line a:5:1
-	//
-}
-`,
-			want: `package main
-
-func a() {
-//line a:5:1
-	//
-}
-`,
-		},
-
-		{
-			src: `package main
-
-// test comment
-//go:directive2
-// test comment
-func main() {
-}
-`,
-			want: `package main
-
-// test comment
-// test comment
-//
-//go:directive2
-func main() {
-}
-`,
-		},
-		{
-			src: `package main
-
-	// test comment
-	//go:directive2
-	// test comment
-func main() {
-}
-`,
-			want: `package main
-
-// test comment
-// test comment
-//
-//go:directive2
-func main() {
-}
-`,
-		},
-		{
-			src: `package main
-
-/* test
- */ // test comment
-//go:directive2
-// test comment
-func main() {
-}
-`,
-			want: `package main
-
-/* test
- */ // test comment
-//go:directive2
-// test comment
-func main() {
-}
-`,
-		},
-
-		{
-			src: `package main  //comment
-var a int = 4 //comment
-func a() {
-}
-`,
-			want: `package main  //comment
-var a int = 4 //comment
-func a() {
-}
-`,
-		},
-
-		// Edge case found by a fuzzer, not a real-world example.
-		{
-			src:  "package A\n\nimport(\"\f\"\n//\n\"\")",
-			want: "package A\n\nimport (\n\t\"\f\" //\n\t\"\"\n)\n",
-		},
-		{
-			src:  "package A\n\nimport(`\f`\n//\n\"\")",
-			want: "package A\n\nimport (\n\t`\f` //\n\t\"\"\n)\n",
-		},
-	}
-
-	for _, tt := range cases {
-		fset := token.NewFileSet()
-		f, err := parser.ParseFile(fset, "test.go", tt.src, parser.ParseComments|parser.SkipObjectResolution)
-		if err != nil {
-			t.Fatal(err)
-		}
-
-		var buf strings.Builder
-		cfg := Config{Tabwidth: 8, Mode: UseSpaces | TabIndent}
-		if err := cfg.Fprint(&buf, fset, f); err != nil {
-			t.Fatal(err)
-		}
-
-		got := buf.String()
-		if got != tt.want {
-			t.Errorf("source\n%v\nformatted as:\n%v\nwant formatted as:\n%v", tt.src, got, tt.want)
-		}
-	}
-}