From: Rob Pike <r@golang.org>
Date: Mon, 9 Feb 2015 19:45:36 +0000 (-0800)
Subject: [dev.cc] cmd/asm: add a couple of error messages for things like $exit
X-Git-Tag: go1.5beta1~1915^2~75
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=b6fd455c0da24e747fc0faa08550f460a615145e;p=gostls13.git

[dev.cc] cmd/asm: add a couple of error messages for things like $exit

These illegal addressing modes were caught downstream in the assembler
or link library, but we can give a better error message upstream.

Change-Id: Ib30ef4d94d5d8d44900276592edd7997e6f91e55
Reviewed-on: https://go-review.googlesource.com/4260
Reviewed-by: Russ Cox <rsc@golang.org>
---

diff --git a/src/cmd/asm/internal/asm/parse.go b/src/cmd/asm/internal/asm/parse.go
index 3e0fb32ee7..8ba0973d97 100644
--- a/src/cmd/asm/internal/asm/parse.go
+++ b/src/cmd/asm/internal/asm/parse.go
@@ -290,6 +290,9 @@ func (p *Parser) operand(a *obj.Addr) bool {
 			a.Type = obj.TYPE_ADDR
 		}
 		a.Reg = r1
+		if r1 == arch.RPC && prefix != 0 {
+			p.errorf("illegal addressing mode for PC")
+		}
 		a.Scale = scale
 		p.get(')')
 		if scale == 0 && p.peek() == '(' {
@@ -363,14 +366,22 @@ func (p *Parser) symbolReference(a *obj.Addr, name string, prefix rune) {
 	}
 	a.Sym = obj.Linklookup(p.linkCtxt, name, isStatic)
 	if p.peek() == scanner.EOF {
+		if prefix != 0 {
+			p.errorf("illegal addressing mode for symbol %s", name)
+		}
 		return
 	}
-	// Expect (SB) or (FP) or (SP).
+	// Expect (SB) or (FP), (PC), (SB), or (SP)
 	p.get('(')
 	reg := p.get(scanner.Ident).String()
 	switch reg {
 	case "FP":
 		a.Name = obj.NAME_PARAM
+	case "PC":
+		// Fine as is.
+		if prefix != 0 {
+			p.errorf("illegal addressing mode for PC")
+		}
 	case "SB":
 		a.Name = obj.NAME_EXTERN
 		if isStatic != 0 {