From 8f00eb009978e2e1bb681e698a0b51e20333eb05 Mon Sep 17 00:00:00 2001 From: Matthew Dempsky Date: Fri, 11 Jun 2021 18:51:56 -0700 Subject: [dev.typeparams] cmd/compile: avoid ir.DeepCopy in noder.constDecl Instead of using ir.DeepCopy to copy the IR from the previous constant declaration, just call exprList again and then fix up the position information. This is equivalent in practice, but has cleaner semantics for tricky corner cases like constant declarations that contain function literals. In particular, this refactoring is necessary for the next CL that cleans up function literal construction, because it adds extra consistency checks that weren't satisfied by DeepCopy'd OCLOSUREs. Change-Id: I0372bde5d6613695ee572cc8bf8fb4ff9aef4cb4 Reviewed-on: https://go-review.googlesource.com/c/go/+/327449 Trust: Matthew Dempsky Run-TryBot: Matthew Dempsky TryBot-Result: Go Bot Reviewed-by: Cuong Manh Le --- src/cmd/compile/internal/noder/noder.go | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'src/cmd/compile/internal/noder/noder.go') diff --git a/src/cmd/compile/internal/noder/noder.go b/src/cmd/compile/internal/noder/noder.go index 08c05a69be..9dc05182d1 100644 --- a/src/cmd/compile/internal/noder/noder.go +++ b/src/cmd/compile/internal/noder/noder.go @@ -450,7 +450,7 @@ func (p *noder) varDecl(decl *syntax.VarDecl) []ir.Node { type constState struct { group *syntax.Group typ ir.Ntype - values []ir.Node + values syntax.Expr iota int64 } @@ -468,16 +468,15 @@ func (p *noder) constDecl(decl *syntax.ConstDecl, cs *constState) []ir.Node { names := p.declNames(ir.OLITERAL, decl.NameList) typ := p.typeExprOrNil(decl.Type) - var values []ir.Node if decl.Values != nil { - values = p.exprList(decl.Values) - cs.typ, cs.values = typ, values + cs.typ, cs.values = typ, decl.Values } else { if typ != nil { base.Errorf("const declaration cannot have type without expression") } - typ, values = cs.typ, cs.values + typ = cs.typ } + values := p.exprList(cs.values) nn := make([]ir.Node, 0, len(names)) for i, n := range names { @@ -485,10 +484,16 @@ func (p *noder) constDecl(decl *syntax.ConstDecl, cs *constState) []ir.Node { base.Errorf("missing value in const declaration") break } + v := values[i] if decl.Values == nil { - v = ir.DeepCopy(n.Pos(), v) + ir.Visit(v, func(v ir.Node) { + if ir.HasUniquePos(v) { + v.SetPos(n.Pos()) + } + }) } + typecheck.Declare(n, typecheck.DeclContext) n.Ntype = typ -- cgit v1.2.3-54-g00ecf