From c77c3236b1d64e99db05059c2a7eed8a8623e3fd Mon Sep 17 00:00:00 2001
From: Robert Griesemer <gri@golang.org>
Date: Fri, 31 Jul 2020 11:38:49 -0700
Subject: [PATCH] [dev.go2go] cmd/compile/internal/types2: remove most
 token.Token dependencies

The remaining uses of token.Token are needed for the go/constant API.

Change-Id: I5dc8be1fae16217433da1acb5606fd1d7b8eea54
Reviewed-on: https://go-review.googlesource.com/c/go/+/246257
Reviewed-by: Robert Griesemer <gri@golang.org>
---
 src/cmd/compile/fmtmap_test.go                |  2 -
 src/cmd/compile/internal/types2/expr.go       |  4 +-
 src/cmd/compile/internal/types2/stmt.go       | 22 ++-------
 src/cmd/compile/internal/types2/token_test.go | 47 -------------------
 4 files changed, 5 insertions(+), 70 deletions(-)
 delete mode 100644 src/cmd/compile/internal/types2/token_test.go

diff --git a/src/cmd/compile/fmtmap_test.go b/src/cmd/compile/fmtmap_test.go
index 366cb5a7bc..3885f4ce17 100644
--- a/src/cmd/compile/fmtmap_test.go
+++ b/src/cmd/compile/fmtmap_test.go
@@ -181,8 +181,6 @@ var knownFormats = map[string]string{
 	"float64 %.6g":                                    "",
 	"float64 %g":                                      "",
 	"go/constant.Value %s":                            "",
-	"go/token.Token %d":                               "",
-	"go/token.Token %s":                               "",
 	"int %#x":                                         "",
 	"int %-12d":                                       "",
 	"int %-6d":                                        "",
diff --git a/src/cmd/compile/internal/types2/expr.go b/src/cmd/compile/internal/types2/expr.go
index c150cfb190..a6e46b9910 100644
--- a/src/cmd/compile/internal/types2/expr.go
+++ b/src/cmd/compile/internal/types2/expr.go
@@ -81,11 +81,11 @@ func (check *Checker) op(m opPredicates, x *operand, op syntax.Operator) bool {
 func op2token(op syntax.Operator) token.Token {
 	switch op {
 	case syntax.Def: // :
-		unimplemented()
+		unreachable()
 	case syntax.Not: // !
 		return token.NOT
 	case syntax.Recv: // <-
-		unimplemented()
+		unreachable()
 
 	case syntax.OrOr: // ||
 		return token.LOR
diff --git a/src/cmd/compile/internal/types2/stmt.go b/src/cmd/compile/internal/types2/stmt.go
index 04145aae69..6f3a2a9216 100644
--- a/src/cmd/compile/internal/types2/stmt.go
+++ b/src/cmd/compile/internal/types2/stmt.go
@@ -9,7 +9,6 @@ package types2
 import (
 	"cmd/compile/internal/syntax"
 	"go/constant"
-	"go/token"
 	"sort"
 )
 
@@ -164,14 +163,6 @@ func (check *Checker) closeScope() {
 	check.scope = check.scope.Parent()
 }
 
-func assignOp(op token.Token) token.Token {
-	// token_test.go verifies the token ordering this function relies on
-	if token.ADD_ASSIGN <= op && op <= token.AND_NOT_ASSIGN {
-		return op + (token.ADD - token.ADD_ASSIGN)
-	}
-	return token.ILLEGAL
-}
-
 func (check *Checker) suspendedCall(keyword string, call *syntax.CallExpr) {
 	var x operand
 	var msg string
@@ -368,9 +359,8 @@ func (check *Checker) stmt(ctxt stmtContext, s syntax.Stmt) {
 	case *syntax.AssignStmt:
 		lhs := unpackExpr(s.Lhs)
 		rhs := unpackExpr(s.Rhs)
-		switch s.Op {
-		// case token.ASSIGN, token.DEFINE:
-		case 0, syntax.Def:
+		if s.Op == 0 || s.Op == syntax.Def {
+			// regular assignment or short variable declaration
 			if len(lhs) == 0 {
 				check.invalidAST(s.Pos(), "missing lhs in assignment")
 				return
@@ -381,18 +371,12 @@ func (check *Checker) stmt(ctxt stmtContext, s syntax.Stmt) {
 				// regular assignment
 				check.assignVars(lhs, rhs)
 			}
-
-		default:
+		} else {
 			// assignment operations
 			if len(lhs) != 1 || len(rhs) != 1 {
 				check.errorf(s.Pos(), "assignment operation %s requires single-valued expressions", s.Op)
 				return
 			}
-			// op := assignOp(s.Tok)
-			// if op == token.ILLEGAL {
-			// 	check.invalidAST(s.Pos(), "unknown assignment operation %s", s.Op)
-			// 	return
-			// }
 			var x operand
 			check.binary(&x, nil, lhs[0], rhs[0], s.Op)
 			if x.mode == invalid {
diff --git a/src/cmd/compile/internal/types2/token_test.go b/src/cmd/compile/internal/types2/token_test.go
deleted file mode 100644
index 63afa6c6ff..0000000000
--- a/src/cmd/compile/internal/types2/token_test.go
+++ /dev/null
@@ -1,47 +0,0 @@
-// Copyright 2013 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.
-
-// This file checks invariants of token.Token ordering that we rely on
-// since package go/token doesn't provide any guarantees at the moment.
-
-package types2
-
-import (
-	"go/token"
-	"testing"
-)
-
-var assignOps = map[token.Token]token.Token{
-	token.ADD_ASSIGN:     token.ADD,
-	token.SUB_ASSIGN:     token.SUB,
-	token.MUL_ASSIGN:     token.MUL,
-	token.QUO_ASSIGN:     token.QUO,
-	token.REM_ASSIGN:     token.REM,
-	token.AND_ASSIGN:     token.AND,
-	token.OR_ASSIGN:      token.OR,
-	token.XOR_ASSIGN:     token.XOR,
-	token.SHL_ASSIGN:     token.SHL,
-	token.SHR_ASSIGN:     token.SHR,
-	token.AND_NOT_ASSIGN: token.AND_NOT,
-}
-
-func TestZeroTok(t *testing.T) {
-	// zero value for token.Token must be token.ILLEGAL
-	var zero token.Token
-	if token.ILLEGAL != zero {
-		t.Errorf("%s == %d; want 0", token.ILLEGAL, zero)
-	}
-}
-
-func TestAssignOp(t *testing.T) {
-	// there are fewer than 256 tokens
-	for i := 0; i < 256; i++ {
-		tok := token.Token(i)
-		got := assignOp(tok)
-		want := assignOps[tok]
-		if got != want {
-			t.Errorf("for assignOp(%s): got %s; want %s", tok, got, want)
-		}
-	}
-}