cmd/compile: give ChanDir a type
Change-Id: I03621db79637b04982e1f0e7b4268c4ed2db6d22
Reviewed-on: https://go-review.googlesource.com/21484
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/cmd/compile/internal/gc/bimport.go b/src/cmd/compile/internal/gc/bimport.go
index 0a51ab0..4bf6f1d 100644
--- a/src/cmd/compile/internal/gc/bimport.go
+++ b/src/cmd/compile/internal/gc/bimport.go
@@ -316,7 +316,7 @@
case chanTag:
t = p.newtyp(TCHAN)
- t.Chan = uint8(p.int())
+ t.Chan = ChanDir(p.int())
t.Type = p.typ()
default:
diff --git a/src/cmd/compile/internal/gc/fmt.go b/src/cmd/compile/internal/gc/fmt.go
index 9480559..5eb9948 100644
--- a/src/cmd/compile/internal/gc/fmt.go
+++ b/src/cmd/compile/internal/gc/fmt.go
@@ -1154,7 +1154,7 @@
return fmt.Sprintf("map[%v]%v", n.Left, n.Right)
case OTCHAN:
- switch n.Etype {
+ switch ChanDir(n.Etype) {
case Crecv:
return fmt.Sprintf("<-chan %v", n.Left)
@@ -1162,7 +1162,7 @@
return fmt.Sprintf("chan<- %v", n.Left)
default:
- if n.Left != nil && n.Left.Op == OTCHAN && n.Left.Sym == nil && n.Left.Etype == Crecv {
+ if n.Left != nil && n.Left.Op == OTCHAN && n.Left.Sym == nil && ChanDir(n.Left.Etype) == Crecv {
return fmt.Sprintf("chan (%v)", n.Left)
} else {
return fmt.Sprintf("chan %v", n.Left)
diff --git a/src/cmd/compile/internal/gc/go.go b/src/cmd/compile/internal/gc/go.go
index 117836d..fdea1f2 100644
--- a/src/cmd/compile/internal/gc/go.go
+++ b/src/cmd/compile/internal/gc/go.go
@@ -128,12 +128,18 @@
CTNIL
)
+// ChanDir is whether a channel can send, receive, or both.
+type ChanDir uint8
+
+func (c ChanDir) CanRecv() bool { return c&Crecv != 0 }
+func (c ChanDir) CanSend() bool { return c&Csend != 0 }
+
const (
// types of channel
// must match ../../../../reflect/type.go:/ChanDir
- Crecv = 1 << 0
- Csend = 1 << 1
- Cboth = Crecv | Csend
+ Crecv ChanDir = 1 << 0
+ Csend ChanDir = 1 << 1
+ Cboth ChanDir = Crecv | Csend
)
// The Class of a variable/function describes the "storage class"
diff --git a/src/cmd/compile/internal/gc/parser.go b/src/cmd/compile/internal/gc/parser.go
index b71cf8f..4649c45 100644
--- a/src/cmd/compile/internal/gc/parser.go
+++ b/src/cmd/compile/internal/gc/parser.go
@@ -1187,17 +1187,17 @@
if x.Op == OTCHAN {
// x is a channel type => re-associate <-
- dir := EType(Csend)
+ dir := Csend
t := x
for ; t.Op == OTCHAN && dir == Csend; t = t.Left {
- dir = t.Etype
+ dir = ChanDir(t.Etype)
if dir == Crecv {
// t is type <-chan E but <-<-chan E is not permitted
// (report same error as for "type _ <-<-chan E")
p.syntax_error("unexpected <-, expecting chan")
// already progressed, no need to advance
}
- t.Etype = Crecv
+ t.Etype = EType(Crecv)
}
if dir == Csend {
// channel dir is <- but channel element E is not a channel
@@ -1697,7 +1697,7 @@
p.next()
p.want(LCHAN)
t := Nod(OTCHAN, p.chan_elem(), nil)
- t.Etype = Crecv
+ t.Etype = EType(Crecv)
return t
case LFUNC:
@@ -1726,9 +1726,9 @@
// LCHAN non_recvchantype
// LCHAN LCOMM ntype
p.next()
- var dir EType = Cboth
+ var dir = EType(Cboth)
if p.got(LCOMM) {
- dir = Csend
+ dir = EType(Csend)
}
t := Nod(OTCHAN, p.chan_elem(), nil)
t.Etype = dir
diff --git a/src/cmd/compile/internal/gc/range.go b/src/cmd/compile/internal/gc/range.go
index 6a28c3c..6adf8e0 100644
--- a/src/cmd/compile/internal/gc/range.go
+++ b/src/cmd/compile/internal/gc/range.go
@@ -58,7 +58,7 @@
t2 = t.Val()
case TCHAN:
- if t.ChanDir()&Crecv == 0 {
+ if !t.ChanDir().CanRecv() {
Yyerror("invalid operation: range %v (receive from send-only type %v)", n.Right, n.Right.Type)
goto out
}
diff --git a/src/cmd/compile/internal/gc/syntax.go b/src/cmd/compile/internal/gc/syntax.go
index b23b466..2f3b98a 100644
--- a/src/cmd/compile/internal/gc/syntax.go
+++ b/src/cmd/compile/internal/gc/syntax.go
@@ -52,7 +52,7 @@
Op Op
Ullman uint8 // sethi/ullman number
Addable bool // addressable
- Etype EType // op for OASOP, etype for OTYPE, exclam for export, 6g saved reg
+ Etype EType // op for OASOP, etype for OTYPE, exclam for export, 6g saved reg, ChanDir for OTCHAN
Bounded bool // bounds check unnecessary
Class Class // PPARAM, PAUTO, PEXTERN, etc
Embedded uint8 // ODCLFIELD embedded type
diff --git a/src/cmd/compile/internal/gc/type.go b/src/cmd/compile/internal/gc/type.go
index d207a04..b89c5db 100644
--- a/src/cmd/compile/internal/gc/type.go
+++ b/src/cmd/compile/internal/gc/type.go
@@ -110,7 +110,7 @@
type Type struct {
Etype EType
Noalg bool
- Chan uint8
+ Chan ChanDir
Trecur uint8 // to detect loops
Printed bool
Funarg bool // on TSTRUCT and TFIELD
@@ -266,7 +266,7 @@
}
// typChan returns a new chan Type with direction dir.
-func typChan(elem *Type, dir uint8) *Type {
+func typChan(elem *Type, dir ChanDir) *Type {
t := typ(TCHAN)
t.Type = elem
t.Chan = dir
@@ -957,7 +957,7 @@
// ChanDir returns the direction of a channel type t.
// The direction will be one of Crecv, Csend, or Cboth.
-func (t *Type) ChanDir() uint8 {
+func (t *Type) ChanDir() ChanDir {
t.wantEtype(TCHAN)
return t.Chan
}
diff --git a/src/cmd/compile/internal/gc/typecheck.go b/src/cmd/compile/internal/gc/typecheck.go
index 6b56621..0b8eb8c 100644
--- a/src/cmd/compile/internal/gc/typecheck.go
+++ b/src/cmd/compile/internal/gc/typecheck.go
@@ -414,7 +414,7 @@
n.Type = nil
return n
}
- t := typChan(l.Type, uint8(n.Etype)) // TODO(marvin): Fix Node.EType type union.
+ t := typChan(l.Type, ChanDir(n.Etype)) // TODO(marvin): Fix Node.EType type union.
n.Op = OTYPE
n.Type = t
n.Left = nil
@@ -1048,7 +1048,7 @@
return n
}
- if t.ChanDir()&Crecv == 0 {
+ if !t.ChanDir().CanRecv() {
Yyerror("invalid operation: %v (receive from send-only type %v)", n, t)
n.Type = nil
return n
@@ -1075,7 +1075,7 @@
return n
}
- if t.ChanDir()&Csend == 0 {
+ if !t.ChanDir().CanSend() {
Yyerror("invalid operation: %v (send to receive-only type %v)", n, t)
n.Type = nil
return n
@@ -1528,7 +1528,7 @@
return n
}
- if t.ChanDir()&Csend == 0 {
+ if !t.ChanDir().CanSend() {
Yyerror("invalid operation: %v (cannot close receive-only channel)", n)
n.Type = nil
return n
