[dev.regabi] cmd/compile: cleanup import/export code

Now that we have concrete AST node types and better constructor APIs,
we can more cleanup a lot of the import code and some export code too.

Passes toolstash -cmp.

Change-Id: Ie3425d9dac11ac4245e5da675dd298984a926df4
Reviewed-on: https://go-review.googlesource.com/c/go/+/279954
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

diff --git a/src/cmd/compile/internal/typecheck/iexport.go b/src/cmd/compile/internal/typecheck/iexport.go
index 4ddee01b5a9c094be17c2180ed32ebdabc4e24b8..95a100e6a5ecd5a83ad0d9f3f5a08b616a00f78b 100644 (file)
--- a/src/cmd/compile/internal/typecheck/iexport.go
+++ b/src/cmd/compile/internal/typecheck/iexport.go
@@ -1155,7 +1155,7 @@ func (w *exportWriter) stmt(n ir.Node) {
                w.pos(n.Pos())
                w.stmtList(n.Init())
                w.exprsOrNil(nil, nil) // TODO(rsc): Delete (and fix importer).
-               w.caseList(n)
+               w.caseList(n.Cases, false)
 
        case ir.OSWITCH:
                n := n.(*ir.SwitchStmt)
@@ -1163,7 +1163,7 @@ func (w *exportWriter) stmt(n ir.Node) {
                w.pos(n.Pos())
                w.stmtList(n.Init())
                w.exprsOrNil(n.Tag, nil)
-               w.caseList(n)
+               w.caseList(n.Cases, isNamedTypeSwitch(n.Tag))
 
        // case OCASE:
        //      handled by caseList
@@ -1187,27 +1187,12 @@ func (w *exportWriter) stmt(n ir.Node) {
        }
 }
 
-func isNamedTypeSwitch(n ir.Node) bool {
-       if n.Op() != ir.OSWITCH {
-               return false
-       }
-       sw := n.(*ir.SwitchStmt)
-       if sw.Tag == nil || sw.Tag.Op() != ir.OTYPESW {
-               return false
-       }
-       guard := sw.Tag.(*ir.TypeSwitchGuard)
-       return guard.Tag != nil
+func isNamedTypeSwitch(x ir.Node) bool {
+       guard, ok := x.(*ir.TypeSwitchGuard)
+       return ok && guard.Tag != nil
 }
 
-func (w *exportWriter) caseList(sw ir.Node) {
-       namedTypeSwitch := isNamedTypeSwitch(sw)
-
-       var cases []ir.Node
-       if sw.Op() == ir.OSWITCH {
-               cases = sw.(*ir.SwitchStmt).Cases
-       } else {
-               cases = sw.(*ir.SelectStmt).Cases
-       }
+func (w *exportWriter) caseList(cases []ir.Node, namedTypeSwitch bool) {
        w.uint64(uint64(len(cases)))
        for _, cas := range cases {
                cas := cas.(*ir.CaseStmt)

diff --git a/src/cmd/compile/internal/typecheck/iimport.go b/src/cmd/compile/internal/typecheck/iimport.go
index ab43d4f71bceb4d34b9ba92b6194d627c0ec73aa..3c7dde5506793bcb1edbbe369b32f1565d60ce9b 100644 (file)
--- a/src/cmd/compile/internal/typecheck/iimport.go
+++ b/src/cmd/compile/internal/typecheck/iimport.go
@@ -767,8 +767,8 @@ func (r *importReader) stmtList() []ir.Node {
        return list
 }
 
-func (r *importReader) caseList(sw ir.Node) []ir.Node {
-       namedTypeSwitch := isNamedTypeSwitch(sw)
+func (r *importReader) caseList(switchExpr ir.Node) []ir.Node {
+       namedTypeSwitch := isNamedTypeSwitch(switchExpr)
 
        cases := make([]ir.Node, r.uint64())
        for i := range cases {
@@ -781,7 +781,7 @@ func (r *importReader) caseList(sw ir.Node) []ir.Node {
                        caseVar := ir.NewNameAt(cas.Pos(), r.ident())
                        Declare(caseVar, DeclContext)
                        cas.Vars = []ir.Node{caseVar}
-                       caseVar.Defn = sw.(*ir.SwitchStmt).Tag
+                       caseVar.Defn = switchExpr
                }
                cas.Body.Set(r.stmtList())
                cases[i] = cas
@@ -821,7 +821,7 @@ func (r *importReader) node() ir.Node {
                pos := r.pos()
                typ := r.typ()
 
-               n := npos(pos, NodNil())
+               n := ir.NewNilExpr(pos)
                n.SetType(typ)
                return n
 
@@ -829,7 +829,7 @@ func (r *importReader) node() ir.Node {
                pos := r.pos()
                typ := r.typ()
 
-               n := npos(pos, ir.NewLiteral(r.value(typ)))
+               n := ir.NewBasicLit(pos, r.value(typ))
                n.SetType(typ)
                return n
 
@@ -864,26 +864,19 @@ func (r *importReader) node() ir.Node {
        //      unreachable - mapped to case OADDR below by exporter
 
        case ir.OSTRUCTLIT:
-               // TODO(mdempsky): Export position information for OSTRUCTKEY nodes.
-               savedlineno := base.Pos
-               base.Pos = r.pos()
-               n := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(r.typ()).(ir.Ntype), nil)
-               n.List.Set(r.elemList()) // special handling of field names
-               base.Pos = savedlineno
-               return n
+               pos := r.pos()
+               return ir.NewCompLitExpr(pos, ir.OCOMPLIT, ir.TypeNode(r.typ()).(ir.Ntype), r.elemList(pos))
 
        // case OARRAYLIT, OSLICELIT, OMAPLIT:
        //      unreachable - mapped to case OCOMPLIT below by exporter
 
        case ir.OCOMPLIT:
-               n := ir.NewCompLitExpr(r.pos(), ir.OCOMPLIT, ir.TypeNode(r.typ()).(ir.Ntype), nil)
-               n.List.Set(r.exprList())
-               return n
+               return ir.NewCompLitExpr(r.pos(), ir.OCOMPLIT, ir.TypeNode(r.typ()).(ir.Ntype), r.exprList())
 
        case ir.OKEY:
                pos := r.pos()
-               left, right := r.exprsOrNil()
-               return ir.NewKeyExpr(pos, left, right)
+               key, value := r.exprsOrNil()
+               return ir.NewKeyExpr(pos, key, value)
 
        // case OSTRUCTKEY:
        //      unreachable - handled in case OSTRUCTLIT by elemList
@@ -926,9 +919,9 @@ func (r *importReader) node() ir.Node {
        //      unreachable - mapped to OCONV case below by exporter
 
        case ir.OCONV:
-               n := ir.NewConvExpr(r.pos(), ir.OCONV, nil, r.expr())
-               n.SetType(r.typ())
-               return n
+               pos := r.pos()
+               x := r.expr()
+               return ir.NewConvExpr(pos, ir.OCONV, r.typ(), x)
 
        case ir.OCOPY, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCAP, ir.OCLOSE, ir.ODELETE, ir.OLEN, ir.OMAKE, ir.ONEW, ir.OPANIC, ir.ORECOVER, ir.OPRINT, ir.OPRINTN:
                n := builtinCall(r.pos(), op)
@@ -942,10 +935,10 @@ func (r *importReader) node() ir.Node {
        //      unreachable - mapped to OCALL case below by exporter
 
        case ir.OCALL:
-               n := ir.NewCallExpr(r.pos(), ir.OCALL, nil, nil)
-               n.PtrInit().Set(r.stmtList())
-               n.X = r.expr()
-               n.Args.Set(r.exprList())
+               pos := r.pos()
+               init := r.stmtList()
+               n := ir.NewCallExpr(pos, ir.OCALL, r.expr(), r.exprList())
+               n.PtrInit().Set(init)
                n.IsDDD = r.bool()
                return n
 
@@ -979,7 +972,8 @@ func (r *importReader) node() ir.Node {
        case ir.OADDSTR:
                pos := r.pos()
                list := r.exprList()
-               x := npos(pos, list[0])
+               x := list[0]
+               x.SetPos(pos) // TODO(mdempsky): Remove toolstash bandage.
                for _, y := range list[1:] {
                        x = ir.NewBinaryExpr(pos, ir.OADD, x, y)
                }
@@ -1006,9 +1000,7 @@ func (r *importReader) node() ir.Node {
                return ir.NewAssignStmt(r.pos(), r.expr(), r.expr())
 
        case ir.OASOP:
-               n := ir.NewAssignOpStmt(r.pos(), ir.OXXX, nil, nil)
-               n.AsOp = r.op()
-               n.X = r.expr()
+               n := ir.NewAssignOpStmt(r.pos(), r.op(), r.expr(), nil)
                if !r.bool() {
                        n.Y = ir.NewInt(1)
                        n.IncDec = true
@@ -1021,15 +1013,10 @@ func (r *importReader) node() ir.Node {
        //      unreachable - mapped to OAS2 case below by exporter
 
        case ir.OAS2:
-               n := ir.NewAssignListStmt(r.pos(), ir.OAS2, nil, nil)
-               n.Lhs.Set(r.exprList())
-               n.Rhs.Set(r.exprList())
-               return n
+               return ir.NewAssignListStmt(r.pos(), ir.OAS2, r.exprList(), r.exprList())
 
        case ir.ORETURN:
-               n := ir.NewReturnStmt(r.pos(), nil)
-               n.Results.Set(r.exprList())
-               return n
+               return ir.NewReturnStmt(r.pos(), r.exprList())
 
        // case ORETJMP:
        //      unreachable - generated by compiler for trampolin routines (not exported)
@@ -1038,57 +1025,47 @@ func (r *importReader) node() ir.Node {
                return ir.NewGoDeferStmt(r.pos(), op, r.expr())
 
        case ir.OIF:
-               n := ir.NewIfStmt(r.pos(), nil, nil, nil)
-               n.PtrInit().Set(r.stmtList())
-               n.Cond = r.expr()
-               n.Body.Set(r.stmtList())
-               n.Else.Set(r.stmtList())
+               pos, init := r.pos(), r.stmtList()
+               n := ir.NewIfStmt(pos, r.expr(), r.stmtList(), r.stmtList())
+               n.PtrInit().Set(init)
                return n
 
        case ir.OFOR:
-               n := ir.NewForStmt(r.pos(), nil, nil, nil, nil)
-               n.PtrInit().Set(r.stmtList())
-               left, right := r.exprsOrNil()
-               n.Cond = left
-               n.Post = right
-               n.Body.Set(r.stmtList())
-               return n
+               pos, init := r.pos(), r.stmtList()
+               cond, post := r.exprsOrNil()
+               return ir.NewForStmt(pos, init, cond, post, r.stmtList())
 
        case ir.ORANGE:
-               n := ir.NewRangeStmt(r.pos(), nil, nil, nil)
-               n.Vars.Set(r.stmtList())
-               n.X = r.expr()
-               n.Body.Set(r.stmtList())
-               return n
+               return ir.NewRangeStmt(r.pos(), r.stmtList(), r.expr(), r.stmtList())
 
        case ir.OSELECT:
-               n := ir.NewSelectStmt(r.pos(), nil)
-               n.PtrInit().Set(r.stmtList())
+               pos := r.pos()
+               init := r.stmtList()
                r.exprsOrNil() // TODO(rsc): Delete (and fix exporter). These are always nil.
-               n.Cases.Set(r.caseList(n))
+               n := ir.NewSelectStmt(pos, r.caseList(nil))
+               n.PtrInit().Set(init)
                return n
 
        case ir.OSWITCH:
-               n := ir.NewSwitchStmt(r.pos(), nil, nil)
-               n.PtrInit().Set(r.stmtList())
-               left, _ := r.exprsOrNil()
-               n.Tag = left
-               n.Cases.Set(r.caseList(n))
+               pos := r.pos()
+               init := r.stmtList()
+               x, _ := r.exprsOrNil()
+               n := ir.NewSwitchStmt(pos, x, r.caseList(x))
+               n.PtrInit().Set(init)
                return n
 
        // case OCASE:
        //      handled by caseList
 
        case ir.OFALL:
-               n := ir.NewBranchStmt(r.pos(), ir.OFALL, nil)
-               return n
+               return ir.NewBranchStmt(r.pos(), ir.OFALL, nil)
 
        // case OEMPTY:
        //      unreachable - not emitted by exporter
 
        case ir.OBREAK, ir.OCONTINUE, ir.OGOTO:
-               var sym *types.Sym
                pos := r.pos()
+               var sym *types.Sym
                if label := r.string(); label != "" {
                        sym = Lookup(label)
                }
@@ -1111,12 +1088,12 @@ func (r *importReader) op() ir.Op {
        return ir.Op(r.uint64())
 }
 
-func (r *importReader) elemList() []ir.Node {
+func (r *importReader) elemList(pos src.XPos) []ir.Node {
        c := r.uint64()
        list := make([]ir.Node, c)
        for i := range list {
-               s := r.ident()
-               list[i] = ir.NewStructKeyExpr(base.Pos, s, r.expr())
+               // TODO(mdempsky): Export position information for OSTRUCTKEY nodes.
+               list[i] = ir.NewStructKeyExpr(pos, r.ident(), r.expr())
        }
        return list
 }
@@ -1135,8 +1112,3 @@ func (r *importReader) exprsOrNil() (a, b ir.Node) {
 func builtinCall(pos src.XPos, op ir.Op) *ir.CallExpr {
        return ir.NewCallExpr(pos, ir.OCALL, ir.NewIdent(base.Pos, types.BuiltinPkg.Lookup(ir.OpNames[op])), nil)
 }
-
-func npos(pos src.XPos, n ir.Node) ir.Node {
-       n.SetPos(pos)
-       return n
-}