cmd/compile: reduce garbage from autolabel
Follow-up to CL 26661
Change-Id: I67c58d17313094675cf0f30ce50d486818ae0dcb
Reviewed-on: https://go-review.googlesource.com/27113
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/cmd/compile/internal/gc/inl.go b/src/cmd/compile/internal/gc/inl.go
index ea49ae1..a669df8 100644
--- a/src/cmd/compile/internal/gc/inl.go
+++ b/src/cmd/compile/internal/gc/inl.go
@@ -766,7 +766,7 @@
ninit.Append(as)
}
- retlabel := autolabel("i")
+ retlabel := autolabel(".i")
retlabel.Etype = 1 // flag 'safe' for escape analysis (no backjumps)
inlgen++
diff --git a/src/cmd/compile/internal/gc/subr.go b/src/cmd/compile/internal/gc/subr.go
index fa4c8e8..c3f2b60 100644
--- a/src/cmd/compile/internal/gc/subr.go
+++ b/src/cmd/compile/internal/gc/subr.go
@@ -248,16 +248,21 @@
// autolabel generates a new Name node for use with
// an automatically generated label.
-// prefix is a short mnemonic (e.g. "s" for switch)
+// prefix is a short mnemonic (e.g. ".s" for switch)
// to help with debugging.
+// It should begin with "." to avoid conflicts with
+// user labels.
func autolabel(prefix string) *Node {
+ if prefix[0] != '.' {
+ Fatalf("autolabel prefix must start with '.', have %q", prefix)
+ }
fn := Curfn
if Curfn == nil {
Fatalf("autolabel outside function")
}
n := fn.Func.Label
fn.Func.Label++
- return newname(LookupN("."+prefix, int(n)))
+ return newname(LookupN(prefix, int(n)))
}
var initSyms []*Sym
diff --git a/src/cmd/compile/internal/gc/swt.go b/src/cmd/compile/internal/gc/swt.go
index dce3e16..f44c747 100644
--- a/src/cmd/compile/internal/gc/swt.go
+++ b/src/cmd/compile/internal/gc/swt.go
@@ -358,7 +358,7 @@
n.Op = OCASE
needvar := n.List.Len() != 1 || n.List.First().Op == OLITERAL
- jmp := Nod(OGOTO, autolabel("s"), nil)
+ jmp := Nod(OGOTO, autolabel(".s"), nil)
if n.List.Len() == 0 {
if def != nil {
Yyerror("more than one default case")
@@ -577,7 +577,7 @@
i.Nbody.Set1(typenil)
} else {
// Jump to default case.
- lbl := autolabel("s")
+ lbl := autolabel(".s")
i.Nbody.Set1(Nod(OGOTO, lbl, nil))
// Wrap default case with label.
blk := Nod(OBLOCK, nil, nil)
