diff options
Diffstat (limited to 'src/cmd/compile/internal/noder/quirks.go')
-rw-r--r-- | src/cmd/compile/internal/noder/quirks.go | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/noder/quirks.go b/src/cmd/compile/internal/noder/quirks.go new file mode 100644 index 0000000000..914c5d2bd7 --- /dev/null +++ b/src/cmd/compile/internal/noder/quirks.go @@ -0,0 +1,450 @@ +// UNREVIEWED + +// Copyright 2021 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package noder + +import ( + "fmt" + + "cmd/compile/internal/base" + "cmd/compile/internal/ir" + "cmd/compile/internal/syntax" + "cmd/compile/internal/types2" + "cmd/internal/src" +) + +// This file defines helper functions useful for satisfying toolstash +// -cmp when compared against the legacy frontend behavior, but can be +// removed after that's no longer a concern. + +// quirksMode controls whether behavior specific to satisfying +// toolstash -cmp is used. +func quirksMode() bool { + return base.Debug.UnifiedQuirks != 0 +} + +// posBasesOf returns all of the position bases in the source files, +// as seen in a straightforward traversal. +// +// This is necessary to ensure position bases (and thus file names) +// get registered in the same order as noder would visit them. +func posBasesOf(noders []*noder) []*syntax.PosBase { + seen := make(map[*syntax.PosBase]bool) + var bases []*syntax.PosBase + + for _, p := range noders { + syntax.Crawl(p.file, func(n syntax.Node) bool { + if b := n.Pos().Base(); !seen[b] { + bases = append(bases, b) + seen[b] = true + } + return false + }) + } + + return bases +} + +// importedObjsOf returns the imported objects (i.e., referenced +// objects not declared by curpkg) from the parsed source files, in +// the order that typecheck used to load their definitions. +// +// This is needed because loading the definitions for imported objects +// can also add file names. +func importedObjsOf(curpkg *types2.Package, info *types2.Info, noders []*noder) []types2.Object { + // This code is complex because it matches the precise order that + // typecheck recursively and repeatedly traverses the IR. It's meant + // to be thrown away eventually anyway. + + seen := make(map[types2.Object]bool) + var objs []types2.Object + + var phase int + + decls := make(map[types2.Object]syntax.Decl) + assoc := func(decl syntax.Decl, names ...*syntax.Name) { + for _, name := range names { + obj, ok := info.Defs[name] + assert(ok) + decls[obj] = decl + } + } + + for _, p := range noders { + syntax.Crawl(p.file, func(n syntax.Node) bool { + switch n := n.(type) { + case *syntax.ConstDecl: + assoc(n, n.NameList...) + case *syntax.FuncDecl: + assoc(n, n.Name) + case *syntax.TypeDecl: + assoc(n, n.Name) + case *syntax.VarDecl: + assoc(n, n.NameList...) + case *syntax.BlockStmt: + return true + } + return false + }) + } + + var visited map[syntax.Decl]bool + + var resolveDecl func(n syntax.Decl) + var resolveNode func(n syntax.Node, top bool) + + resolveDecl = func(n syntax.Decl) { + if visited[n] { + return + } + visited[n] = true + + switch n := n.(type) { + case *syntax.ConstDecl: + resolveNode(n.Type, true) + resolveNode(n.Values, true) + + case *syntax.FuncDecl: + if n.Recv != nil { + resolveNode(n.Recv, true) + } + resolveNode(n.Type, true) + + case *syntax.TypeDecl: + resolveNode(n.Type, true) + + case *syntax.VarDecl: + if n.Type != nil { + resolveNode(n.Type, true) + } else { + resolveNode(n.Values, true) + } + } + } + + resolveObj := func(pos syntax.Pos, obj types2.Object) { + switch obj.Pkg() { + case nil: + // builtin; nothing to do + + case curpkg: + if decl, ok := decls[obj]; ok { + resolveDecl(decl) + } + + default: + if obj.Parent() == obj.Pkg().Scope() && !seen[obj] { + seen[obj] = true + objs = append(objs, obj) + } + } + } + + checkdefat := func(pos syntax.Pos, n *syntax.Name) { + if n.Value == "_" { + return + } + obj, ok := info.Uses[n] + if !ok { + obj, ok = info.Defs[n] + if !ok { + return + } + } + if obj == nil { + return + } + resolveObj(pos, obj) + } + checkdef := func(n *syntax.Name) { checkdefat(n.Pos(), n) } + + var later []syntax.Node + + resolveNode = func(n syntax.Node, top bool) { + if n == nil { + return + } + syntax.Crawl(n, func(n syntax.Node) bool { + switch n := n.(type) { + case *syntax.Name: + checkdef(n) + + case *syntax.SelectorExpr: + if name, ok := n.X.(*syntax.Name); ok { + if _, isPkg := info.Uses[name].(*types2.PkgName); isPkg { + checkdefat(n.X.Pos(), n.Sel) + return true + } + } + + case *syntax.AssignStmt: + resolveNode(n.Rhs, top) + resolveNode(n.Lhs, top) + return true + + case *syntax.VarDecl: + resolveNode(n.Values, top) + + case *syntax.FuncLit: + if top { + resolveNode(n.Type, top) + later = append(later, n.Body) + return true + } + + case *syntax.BlockStmt: + if phase >= 3 { + for _, stmt := range n.List { + resolveNode(stmt, false) + } + } + return true + } + + return false + }) + } + + for phase = 1; phase <= 5; phase++ { + visited = map[syntax.Decl]bool{} + + for _, p := range noders { + for _, decl := range p.file.DeclList { + switch decl := decl.(type) { + case *syntax.ConstDecl: + resolveDecl(decl) + + case *syntax.FuncDecl: + resolveDecl(decl) + if phase >= 3 && decl.Body != nil { + resolveNode(decl.Body, true) + } + + case *syntax.TypeDecl: + if !decl.Alias || phase >= 2 { + resolveDecl(decl) + } + + case *syntax.VarDecl: + if phase >= 2 { + resolveNode(decl.Values, true) + resolveDecl(decl) + } + } + } + + if phase >= 5 { + syntax.Crawl(p.file, func(n syntax.Node) bool { + if name, ok := n.(*syntax.Name); ok { + if obj, ok := info.Uses[name]; ok { + resolveObj(name.Pos(), obj) + } + } + return false + }) + } + } + + for i := 0; i < len(later); i++ { + resolveNode(later[i], true) + } + later = nil + } + + return objs +} + +// typeExprEndPos returns the position that noder would leave base.Pos +// after parsing the given type expression. +func typeExprEndPos(expr0 syntax.Expr) syntax.Pos { + for { + switch expr := expr0.(type) { + case *syntax.Name: + return expr.Pos() + case *syntax.SelectorExpr: + return expr.X.Pos() + + case *syntax.ParenExpr: + expr0 = expr.X + + case *syntax.Operation: + assert(expr.Op == syntax.Mul) + assert(expr.Y == nil) + expr0 = expr.X + + case *syntax.ArrayType: + expr0 = expr.Elem + case *syntax.ChanType: + expr0 = expr.Elem + case *syntax.DotsType: + expr0 = expr.Elem + case *syntax.MapType: + expr0 = expr.Value + case *syntax.SliceType: + expr0 = expr.Elem + + case *syntax.StructType: + return expr.Pos() + + case *syntax.InterfaceType: + expr0 = lastFieldType(expr.MethodList) + if expr0 == nil { + return expr.Pos() + } + + case *syntax.FuncType: + expr0 = lastFieldType(expr.ResultList) + if expr0 == nil { + expr0 = lastFieldType(expr.ParamList) + if expr0 == nil { + return expr.Pos() + } + } + + case *syntax.IndexExpr: // explicit type instantiation + targs := unpackListExpr(expr.Index) + expr0 = targs[len(targs)-1] + + default: + panic(fmt.Sprintf("%s: unexpected type expression %v", expr.Pos(), syntax.String(expr))) + } + } +} + +func lastFieldType(fields []*syntax.Field) syntax.Expr { + if len(fields) == 0 { + return nil + } + return fields[len(fields)-1].Type +} + +// sumPos returns the position that noder.sum would produce for +// constant expression x. +func sumPos(x syntax.Expr) syntax.Pos { + orig := x + for { + switch x1 := x.(type) { + case *syntax.BasicLit: + assert(x1.Kind == syntax.StringLit) + return x1.Pos() + case *syntax.Operation: + assert(x1.Op == syntax.Add && x1.Y != nil) + if r, ok := x1.Y.(*syntax.BasicLit); ok { + assert(r.Kind == syntax.StringLit) + x = x1.X + continue + } + } + return orig.Pos() + } +} + +// funcParamsEndPos returns the value of base.Pos left by noder after +// processing a function signature. +func funcParamsEndPos(fn *ir.Func) src.XPos { + sig := fn.Nname.Type() + + fields := sig.Results().FieldSlice() + if len(fields) == 0 { + fields = sig.Params().FieldSlice() + if len(fields) == 0 { + fields = sig.Recvs().FieldSlice() + if len(fields) == 0 { + if fn.OClosure != nil { + return fn.Nname.Ntype.Pos() + } + return fn.Pos() + } + } + } + + return fields[len(fields)-1].Pos +} + +type dupTypes struct { + origs map[types2.Type]types2.Type +} + +func (d *dupTypes) orig(t types2.Type) types2.Type { + if orig, ok := d.origs[t]; ok { + return orig + } + return t +} + +func (d *dupTypes) add(t, orig types2.Type) { + if t == orig { + return + } + + if d.origs == nil { + d.origs = make(map[types2.Type]types2.Type) + } + assert(d.origs[t] == nil) + d.origs[t] = orig + + switch t := t.(type) { + case *types2.Pointer: + orig := orig.(*types2.Pointer) + d.add(t.Elem(), orig.Elem()) + + case *types2.Slice: + orig := orig.(*types2.Slice) + d.add(t.Elem(), orig.Elem()) + + case *types2.Map: + orig := orig.(*types2.Map) + d.add(t.Key(), orig.Key()) + d.add(t.Elem(), orig.Elem()) + + case *types2.Array: + orig := orig.(*types2.Array) + assert(t.Len() == orig.Len()) + d.add(t.Elem(), orig.Elem()) + + case *types2.Chan: + orig := orig.(*types2.Chan) + assert(t.Dir() == orig.Dir()) + d.add(t.Elem(), orig.Elem()) + + case *types2.Struct: + orig := orig.(*types2.Struct) + assert(t.NumFields() == orig.NumFields()) + for i := 0; i < t.NumFields(); i++ { + d.add(t.Field(i).Type(), orig.Field(i).Type()) + } + + case *types2.Interface: + orig := orig.(*types2.Interface) + assert(t.NumExplicitMethods() == orig.NumExplicitMethods()) + assert(t.NumEmbeddeds() == orig.NumEmbeddeds()) + for i := 0; i < t.NumExplicitMethods(); i++ { + d.add(t.ExplicitMethod(i).Type(), orig.ExplicitMethod(i).Type()) + } + for i := 0; i < t.NumEmbeddeds(); i++ { + d.add(t.EmbeddedType(i), orig.EmbeddedType(i)) + } + + case *types2.Signature: + orig := orig.(*types2.Signature) + assert((t.Recv() == nil) == (orig.Recv() == nil)) + if t.Recv() != nil { + d.add(t.Recv().Type(), orig.Recv().Type()) + } + d.add(t.Params(), orig.Params()) + d.add(t.Results(), orig.Results()) + + case *types2.Tuple: + orig := orig.(*types2.Tuple) + assert(t.Len() == orig.Len()) + for i := 0; i < t.Len(); i++ { + d.add(t.At(i).Type(), orig.At(i).Type()) + } + + default: + assert(types2.Identical(t, orig)) + } +} |