From: Matthew Dempsky <mdempsky@google.com>
Date: Mon, 10 Jan 2022 19:18:39 +0000 (+0000)
Subject: Revert "cmd/compile: unique LinkString for renamed, embedded fields"
X-Git-Tag: go1.18beta2~130
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=55d10acb72c2dc5524aae69ade560f3cf308a864;p=gostls13.git

Revert "cmd/compile: unique LinkString for renamed, embedded fields"

This reverts CL 372914.

Reason for revert: missing synchronization

Change-Id: I7ebb6de082cebb73741d803ff00e3465bbafab81
Reviewed-on: https://go-review.googlesource.com/c/go/+/377379
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Dan Scales <danscales@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
---

diff --git a/src/cmd/compile/internal/types/fmt.go b/src/cmd/compile/internal/types/fmt.go
index 1399483424..3198a1f53c 100644
--- a/src/cmd/compile/internal/types/fmt.go
+++ b/src/cmd/compile/internal/types/fmt.go
@@ -631,7 +631,6 @@ func fldconv(b *bytes.Buffer, f *Field, verb rune, mode fmtMode, visited map[*Ty
 	}
 
 	var name string
-	nameSep := " "
 	if verb != 'S' {
 		s := f.Sym
 
@@ -640,41 +639,9 @@ func fldconv(b *bytes.Buffer, f *Field, verb rune, mode fmtMode, visited map[*Ty
 			s = OrigSym(s)
 		}
 
-		if s != nil {
+		if s != nil && f.Embedded == 0 {
 			if funarg != FunargNone {
 				name = fmt.Sprint(f.Nname)
-			} else if f.Embedded != 0 {
-				// Using type aliases and embedded fields, it's possible to
-				// construct types that can't be directly represented as a
-				// type literal. For example, given "type Int = int" (#50190),
-				// it would be incorrect to format "struct{ Int }" as either
-				// "struct{ int }" or "struct{ Int int }", because those each
-				// represent other, distinct types.
-				//
-				// So for the purpose of LinkString (i.e., fmtTypeID), we use
-				// the non-standard syntax "struct{ Int = int }" to represent
-				// embedded fields that have been renamed through the use of
-				// type aliases.
-				if mode == fmtTypeID {
-					// Compute styp, the symbol that would normally be used as
-					// the field name when embedding f.Type.
-					// TODO(mdempsky): Check for other occurences of this logic
-					// and deduplicate.
-					typ := f.Type
-					if typ.Sym() == nil && typ.IsPtr() {
-						typ = typ.Elem()
-					}
-					styp := typ.Sym()
-					if styp != nil && IsExported(styp.Name) {
-						styp = LocalPkg.Lookup(styp.Name)
-					}
-
-					// If embedded field was renamed, use syntax extension.
-					if s != styp {
-						name = sconv(s, 0, mode)
-						nameSep = " = "
-					}
-				}
 			} else if verb == 'L' {
 				name = s.Name
 				if name == ".F" {
@@ -691,7 +658,7 @@ func fldconv(b *bytes.Buffer, f *Field, verb rune, mode fmtMode, visited map[*Ty
 
 	if name != "" {
 		b.WriteString(name)
-		b.WriteString(nameSep)
+		b.WriteString(" ")
 	}
 
 	if f.IsDDD() {
diff --git a/test/fixedbugs/issue50190.go b/test/fixedbugs/issue50190.go
deleted file mode 100644
index 01ff6eacaa..0000000000
--- a/test/fixedbugs/issue50190.go
+++ /dev/null
@@ -1,21 +0,0 @@
-// run
-
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package main
-
-type int float32
-
-type Int = int
-
-type A = struct{ int }
-type B = struct{ Int }
-
-func main() {
-	var x, y interface{} = A{}, B{}
-	if x == y {
-		panic("FAIL")
-	}
-}