go/types: include link to source in generated files

This makes navigation a little easier.
Also, make the "inconsistent generated files" test's
error message more explicit about which file is which.

Change-Id: Iae1fb9e496fb68325448d807469a5b0c55ceda99
Reviewed-on: https://go-review.googlesource.com/c/go/+/574715
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Alan Donovan <adonovan@google.com>

src/go/types/alias.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/alias.go
 
 // Copyright 2023 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/api_predicates.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/api_predicates.go
 
 // Copyright 2023 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/array.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/array.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/assignments.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/assignments.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/basic.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/basic.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/builtins.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/builtins.go
 
 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/builtins_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/builtins_test.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/chan.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/chan.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/const.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/const.go
 
 // Copyright 2023 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/context.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/context.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/context_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/context_test.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/conversions.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/conversions.go
 
 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/errors_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/errors_test.go
 
 // Copyright 2020 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/errsupport.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/errsupport.go
 
 // Copyright 2024 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/gccgosizes.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/gccgosizes.go
 
 // Copyright 2019 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/gcsizes.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/gcsizes.go
 
 // Copyright 2023 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/generate_test.go

@@ -10,6 +10,7 @@ package types_test
 import (
 	"bytes"
 	"flag"
+	"fmt"
 	"go/ast"
 	"go/format"
 	"go/parser"
@@ -51,7 +52,7 @@ func TestGenerate(t *testing.T) {
 }
 
 func generate(t *testing.T, filename string, write bool) {
-	// parse src
+	// parse src (cmd/compile/internal/types2)
 	srcFilename := filepath.FromSlash(runtime.GOROOT() + srcDir + filename)
 	file, err := parser.ParseFile(fset, srcFilename, nil, parser.ParseComments)
 	if err != nil {
@@ -68,26 +69,30 @@ func generate(t *testing.T, filename string, write bool) {
 
 	// format AST
 	var buf bytes.Buffer
-	buf.WriteString("// Code generated by \"go test -run=Generate -write=all\"; DO NOT EDIT.\n\n")
+	rel, _ := filepath.Rel(dstDir, srcDir)
+	fmt.Fprintf(&buf, "// Code generated by \"go test -run=Generate -write=all\"; DO NOT EDIT.\n")
+	fmt.Fprintf(&buf, "// Source: %s/%s\n\n", filepath.ToSlash(rel), filename)
 	if err := format.Node(&buf, fset, file); err != nil {
 		t.Fatal(err)
 	}
 	generatedContent := buf.Bytes()
 
+	// read dst (go/types)
 	dstFilename := filepath.FromSlash(runtime.GOROOT() + dstDir + filename)
 	onDiskContent, err := os.ReadFile(dstFilename)
 	if err != nil {
 		t.Fatalf("reading %q: %v", filename, err)
 	}
 
-	if d := diff.Diff(filename+" (on disk)", onDiskContent, filename+" (generated)", generatedContent); d != nil {
+	// compare on-disk dst with buffer generated from src.
+	if d := diff.Diff(filename+" (on disk in "+dstDir+")", onDiskContent, filename+" (generated from "+srcDir+")", generatedContent); d != nil {
 		if write {
 			t.Logf("applying change:\n%s", d)
 			if err := os.WriteFile(dstFilename, generatedContent, 0o644); err != nil {
 				t.Fatalf("writing %q: %v", filename, err)
 			}
 		} else {
-			t.Errorf("generated file content does not match:\n%s", string(d))
+			t.Errorf("file on disk in %s is stale:\n%s", dstDir, d)
 		}
 	}
 }

src/go/types/hilbert_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/hilbert_test.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/infer.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/infer.go
 
 // Copyright 2018 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/initorder.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/initorder.go
 
 // Copyright 2014 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/instantiate.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/instantiate.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/instantiate_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/instantiate_test.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/lookup.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/lookup.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/main_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/main_test.go
 
 // Copyright 2022 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/map.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/map.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/mono.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/mono.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/named.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/named.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/object.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/object.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/object_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/object_test.go
 
 // Copyright 2016 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/objset.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/objset.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/operand.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/operand.go
 
 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/package.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/package.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/pointer.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/pointer.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/predicates.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/predicates.go
 
 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/scope.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/scope.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/selection.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/selection.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/sizes.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/sizes.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/slice.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/slice.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/subst.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/subst.go
 
 // Copyright 2018 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/termlist.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/termlist.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/termlist_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/termlist_test.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/tuple.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/tuple.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/typelists.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/typelists.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/typeparam.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/typeparam.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/typeset.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/typeset.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/typestring.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/typestring.go
 
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/typeterm.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/typeterm.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/typeterm_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/typeterm_test.go
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/under.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/under.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/unify.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/unify.go
 
 // Copyright 2020 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/universe.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/universe.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/util_test.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/util_test.go
 
 // Copyright 2023 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/go/types/validtype.go

@@ -1,4 +1,5 @@
 // Code generated by "go test -run=Generate -write=all"; DO NOT EDIT.
+// Source: ../../cmd/compile/internal/types2/validtype.go
 
 // Copyright 2022 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style