Commit 9f26b9b9 authored by Matthew Dempsky's avatar Matthew Dempsky

cmd/compile: eliminate iota_

Change-Id: Iad9c1961aedcc754ad2f6010a49f94c5a0a4bfee
Reviewed-on: https://go-review.googlesource.com/32487
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarJosh Bleecher Snyder <josharian@gmail.com>
parent 986768de
......@@ -288,7 +288,7 @@ func variter(vl []*Node, t *Node, el []*Node) []*Node {
// declare constants from grammar
// new_name_list [[type] = expr_list]
func constiter(vl []*Node, t *Node, cl []*Node) []*Node {
func constiter(vl []*Node, t *Node, cl []*Node, iotaVal int64) []*Node {
var lno src.XPos // default is to leave line number alone in listtreecopy
if len(cl) == 0 {
if t != nil {
......@@ -301,31 +301,29 @@ func constiter(vl []*Node, t *Node, cl []*Node) []*Node {
lastconst = cl
lasttype = t
}
clcopy := listtreecopy(cl, lno)
var vv []*Node
for _, v := range vl {
if len(clcopy) == 0 {
for i, v := range vl {
if i >= len(cl) {
yyerror("missing value in const declaration")
break
}
c := clcopy[0]
clcopy = clcopy[1:]
c := treecopy(cl[i], lno)
v.Op = OLITERAL
declare(v, dclcontext)
v.Name.Param.Ntype = t
v.Name.Defn = c
v.SetIota(iotaVal)
vv = append(vv, nod(ODCLCONST, v, nil))
}
if len(clcopy) != 0 {
if len(cl) > len(vl) {
yyerror("extra expression in const declaration")
}
iota_ += 1
return vv
}
......@@ -401,9 +399,7 @@ func oldname(s *Sym) *Node {
// Maybe a top-level declaration will come along later to
// define s. resolve will check s.Def again once all input
// source has been processed.
n = newnoname(s)
n.SetIota(iota_) // save current iota value in const declarations
return n
return newnoname(s)
}
if Curfn != nil && n.Op == ONAME && n.Name.Funcdepth > 0 && n.Name.Funcdepth != funcdepth {
......
......@@ -223,8 +223,6 @@ var dclcontext Class // PEXTERN/PAUTO
var statuniqgen int // name generator for static temps
var iota_ int64
var lastconst []*Node
var lasttype *Node
......
......@@ -679,7 +679,6 @@ func findpkg(name string) (file string, ok bool) {
// but does not make them visible to user code.
func loadsys() {
block = 1
iota_ = -1000000
importpkg = Runtimepkg
typecheckok = true
......
......@@ -85,7 +85,6 @@ type linkname struct {
func (p *noder) node() {
block = 1
iota_ = -1000000
imported_unsafe = false
p.lineno(p.file.PkgName)
......@@ -134,22 +133,18 @@ func (p *noder) decls(decls []syntax.Decl) (l []*Node) {
case *syntax.ConstDecl:
// Tricky to handle golang.org/issue/15550 correctly.
prevIota := iota_
if decl.Group == nil || decl.Group != lastConstGroup {
iotaVal = 0
lastConstRHS = nil
}
iota_ = iotaVal
lastconst = lastConstRHS
l = append(l, p.constDecl(decl)...)
l = append(l, p.constDecl(decl, iotaVal)...)
lastConstRHS = lastconst
lastconst = nil
iota_ = prevIota
iotaVal++
lastConstGroup = decl.Group
......@@ -227,7 +222,7 @@ func (p *noder) varDecl(decl *syntax.VarDecl) []*Node {
return variter(names, typ, exprs)
}
func (p *noder) constDecl(decl *syntax.ConstDecl) []*Node {
func (p *noder) constDecl(decl *syntax.ConstDecl, iotaVal int64) []*Node {
names := p.declNames(decl.NameList)
typ := p.typeExprOrNil(decl.Type)
......@@ -236,7 +231,7 @@ func (p *noder) constDecl(decl *syntax.ConstDecl) []*Node {
exprs = p.exprList(decl.Values)
}
return constiter(names, typ, exprs)
return constiter(names, typ, exprs, iotaVal)
}
func (p *noder) typeDecl(decl *syntax.TypeDecl) *Node {
......
......@@ -476,28 +476,13 @@ func treecopy(n *Node, pos src.XPos) *Node {
}
return &m
case ONONAME:
if n.Sym == lookup("iota") {
// Not sure yet whether this is the real iota,
// but make a copy of the Node* just in case,
// so that all the copies of this const definition
// don't have the same iota value.
m := *n
if pos.IsKnown() {
m.Pos = pos
}
m.SetIota(iota_)
return &m
}
return n
case OPACK:
// OPACK nodes are never valid in const value declarations,
// but allow them like any other declared symbol to avoid
// crashing (golang.org/issue/11361).
fallthrough
case ONAME, OLITERAL, OTYPE:
case ONAME, ONONAME, OLITERAL, OTYPE:
return n
}
......
......@@ -43,7 +43,7 @@ type Node struct {
// - ODOT, ODOTPTR, and OINDREGSP use it to indicate offset relative to their base address.
// - OSTRUCTKEY uses it to store the named field's offset.
// - OXCASE and OXFALL use it to validate the use of fallthrough.
// - ONONAME uses it to store the current value of iota, see Node.Iota
// - Named OLITERALs use it to to store their ambient iota value.
// Possibly still more uses. If you find any, document them.
Xoffset int64
......
......@@ -36,8 +36,11 @@ func resolve(n *Node) *Node {
if r != nil {
if r.Op != OIOTA {
n = r
} else if n.Iota() >= 0 {
n = nodintconst(n.Iota())
} else if len(typecheckdefstack) > 0 {
x := typecheckdefstack[len(typecheckdefstack)-1]
if x.Op == OLITERAL {
n = nodintconst(x.Iota())
}
}
}
}
......
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