From 89162307cd2ddf0a514d3a3ed9f7b94e45f1cb15 Mon Sep 17 00:00:00 2001
From: Rob Pike <r@golang.org>
Date: Fri, 23 Jan 2015 11:24:42 -0800
Subject: [PATCH] [dev.cc] cmd/asm: changes to get identical output as new6a

Fix up a couple of minor things pointed out in the last review.
Also:

1. If the symbol starts with center dot, prefix the name with "".
2. If there is no locals size specified, use ArgsSizeUnknown (sic).
3. Do not emit a history point at the start of a macro invocation,
since we do not pop it at the end, behavior consistent with the
old code.

With these changes, old and new assemblers produce identical
output at least for my simple test case, so that provides a verifiable
check for future cleanups.

Change-Id: Iaa91d8e453109824b4be44321ec5e828f39f0299
Reviewed-on: https://go-review.googlesource.com/3242
Reviewed-by: Russ Cox <rsc@golang.org>
---
 src/cmd/asm/internal/asm/asm.go       | 4 ++--
 src/cmd/asm/internal/lex/input.go     | 4 ++--
 src/cmd/asm/internal/lex/lex.go       | 9 ++++++++-
 src/cmd/asm/internal/lex/tokenizer.go | 8 ++++++--
 src/cmd/asm/main.go                   | 3 +--
 5 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/src/cmd/asm/internal/asm/asm.go b/src/cmd/asm/internal/asm/asm.go
index 4ffbe558c60..29166ccf02a 100644
--- a/src/cmd/asm/internal/asm/asm.go
+++ b/src/cmd/asm/internal/asm/asm.go
@@ -144,7 +144,7 @@ func (p *Parser) asmText(word string, operands [][]lex.Token) {
 	if !nameAddr.Is(addr.Symbol|addr.Register|addr.Indirect) || nameAddr.Register != arch.RSB {
 		p.errorf("TEXT symbol %q must be an offset from SB", nameAddr.Symbol)
 	}
-	name := strings.Replace(nameAddr.Symbol, "·", ".", 1)
+	name := nameAddr.Symbol
 
 	// Operand 1 is the text flag, a literal integer.
 	flagAddr := p.address(operands[1])
@@ -160,7 +160,7 @@ func (p *Parser) asmText(word string, operands [][]lex.Token) {
 	// Not clear we can do better, but it doesn't matter.
 	op := operands[2]
 	n := len(op)
-	var locals int64
+	locals := int64(obj.ArgsSizeUnknown)
 	if n >= 2 && op[n-2].ScanToken == '-' && op[n-1].ScanToken == scanner.Int {
 		p.start(op[n-1:])
 		locals = int64(p.expr())
diff --git a/src/cmd/asm/internal/lex/input.go b/src/cmd/asm/internal/lex/input.go
index ae319982391..eefd6eb6efe 100644
--- a/src/cmd/asm/internal/lex/input.go
+++ b/src/cmd/asm/internal/lex/input.go
@@ -234,7 +234,7 @@ func (in *Input) macroDefinition(name string) ([]string, []Token) {
 				continue
 			}
 		}
-		tokens = append(tokens, Token{ScanToken(tok), in.Text()})
+		tokens = append(tokens, Make(tok, in.Text()))
 		tok = in.Stack.Next()
 	}
 	return args, tokens
@@ -305,7 +305,7 @@ func (in *Input) argsFor(macro *Macro) map[string][]Token {
 				return args
 			}
 		default:
-			tokens = append(tokens, Token{tok, in.Stack.Text()})
+			tokens = append(tokens, Make(tok, in.Stack.Text()))
 		}
 	}
 }
diff --git a/src/cmd/asm/internal/lex/lex.go b/src/cmd/asm/internal/lex/lex.go
index 2153591e31a..4785350b1f5 100644
--- a/src/cmd/asm/internal/lex/lex.go
+++ b/src/cmd/asm/internal/lex/lex.go
@@ -107,6 +107,13 @@ type Token struct {
 
 // Make returns a Token with the given rune (ScanToken) and text representation.
 func Make(token ScanToken, text string) Token {
+	// If the symbol starts with center dot, as in ·x, rewrite it as ""·x
+	if token == scanner.Ident && strings.HasPrefix(text, "\u00B7") {
+		text = `""` + text
+	}
+	// Substitute the substitutes for . and /.
+	text = strings.Replace(text, "\u00B7", ".", 1)
+	text = strings.Replace(text, "\u2215", "/", -1)
 	return Token{ScanToken: token, text: text}
 }
 
@@ -130,7 +137,7 @@ func tokenize(str string) []Token {
 		if tok == scanner.EOF {
 			break
 		}
-		tokens = append(tokens, Token{ScanToken: tok, text: t.Text()})
+		tokens = append(tokens, Make(tok, t.Text()))
 	}
 	return tokens
 }
diff --git a/src/cmd/asm/internal/lex/tokenizer.go b/src/cmd/asm/internal/lex/tokenizer.go
index 6a6fdbc7766..24a72479db5 100644
--- a/src/cmd/asm/internal/lex/tokenizer.go
+++ b/src/cmd/asm/internal/lex/tokenizer.go
@@ -39,7 +39,9 @@ func NewTokenizer(name string, r io.Reader, file *os.File) *Tokenizer {
 		scanner.ScanComments
 	s.Position.Filename = name
 	s.IsIdentRune = isIdentRune
-	obj.Linklinehist(linkCtxt, histLine, name, 0)
+	if file != nil {
+		obj.Linklinehist(linkCtxt, histLine, name, 0)
+	}
 	return &Tokenizer{
 		s:        &s,
 		line:     1,
@@ -107,7 +109,9 @@ func (t *Tokenizer) Next() ScanToken {
 	}
 	switch t.tok {
 	case '\n':
-		histLine++
+		if t.file != nil {
+			histLine++
+		}
 		t.line++
 	case '-':
 		if s.Peek() == '>' {
diff --git a/src/cmd/asm/main.go b/src/cmd/asm/main.go
index 08354119a68..3c02d4eebd5 100644
--- a/src/cmd/asm/main.go
+++ b/src/cmd/asm/main.go
@@ -30,8 +30,7 @@ func main() {
 		log.Fatalf("asm: unrecognized architecture %s", GOARCH)
 	}
 
-	// Is this right?
-	flags.Parse(build.Default.GOROOT, build.Default.GOOS, GOARCH, architecture.Thechar)
+	flags.Parse(obj.Getgoroot(), obj.Getgoos(), obj.Getgoarch(), architecture.Thechar)
 
 	// Create object file, write header.
 	fd, err := os.Create(*flags.OutputFile)