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// Copyright 2018 The CUE Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package cue
import (
"fmt"
"strconv"
"strings"
"cuelang.org/go/cue/ast"
"cuelang.org/go/cue/build"
"cuelang.org/go/cue/errors"
"cuelang.org/go/cue/literal"
"cuelang.org/go/cue/token"
"cuelang.org/go/internal"
)
// insertFile inserts the given file at the root of the instance.
//
// The contents will be merged (unified) with any pre-existing value. In this
// case an error may be reported, but only if the merge failed at the top-level.
// Other errors will be recorded at the respective values in the tree.
//
// There should be no unresolved identifiers in file, meaning the Node field
// of all identifiers should be set to a non-nil value.
func (inst *Instance) insertFile(f *ast.File) errors.Error {
// TODO: insert by converting to value first so that the trim command can
// also remove top-level fields.
// First process single file.
v := newVisitor(inst.index, inst.inst, inst.rootStruct, inst.scope)
v.astState.astMap[f] = inst.rootStruct
// TODO: fix cmd/import to resolve references in the AST before
// inserting. For now, we accept errors that did not make it up to the tree.
result := v.walk(f)
if isBottom(result) {
if v.errors != nil {
return v.errors
}
v := newValueRoot(v.ctx(), result)
return v.toErr(result.(*bottom))
}
return nil
}
type astVisitor struct {
*astState
object *structLit
parent *astVisitor
sel string // label or index; may be '*'
// For single line fields, the doc comment is applied to the inner-most
// field value.
//
// // This comment is for bar.
// foo bar: value
//
doc *docNode
inSelector int
}
func (v *astVisitor) ctx() *context {
return v.astState.ctx
}
type astState struct {
ctx *context
*index
inst *build.Instance
litParser *litParser
resolveRoot *structLit
// make unique per level to avoid reuse of structs being an issue.
astMap map[ast.Node]scope
errors errors.Error
}
func (s *astState) mapScope(n ast.Node) (m scope) {
if m = s.astMap[n]; m == nil {
m = newStruct(newNode(n))
s.astMap[n] = m
}
return m
}
func (s *astState) setScope(n ast.Node, v scope) {
if m, ok := s.astMap[n]; ok && m != v {
panic("already defined")
}
s.astMap[n] = v
}
func newVisitor(idx *index, inst *build.Instance, obj, resolveRoot *structLit) *astVisitor {
ctx := idx.newContext()
return newVisitorCtx(ctx, inst, obj, resolveRoot)
}
func newVisitorCtx(ctx *context, inst *build.Instance, obj, resolveRoot *structLit) *astVisitor {
v := &astVisitor{
object: obj,
}
v.astState = &astState{
ctx: ctx,
index: ctx.index,
inst: inst,
litParser: &litParser{ctx: ctx},
resolveRoot: resolveRoot,
astMap: map[ast.Node]scope{},
}
return v
}
func (v *astVisitor) errf(n ast.Node, format string, args ...interface{}) evaluated {
v.astState.errors = errors.Append(v.astState.errors, &nodeError{
path: v.appendPath(nil),
n: n,
Message: errors.NewMessage(format, args),
})
arguments := append([]interface{}{format}, args...)
return v.mkErr(newNode(n), arguments...)
}
func (v *astVisitor) appendPath(a []string) []string {
if v.parent != nil {
a = v.parent.appendPath(a)
}
if v.sel != "" {
a = append(a, v.sel)
}
return a
}
func (v *astVisitor) resolve(n *ast.Ident) value {
ctx := v.ctx()
label := v.label(n.Name, true)
if r := v.resolveRoot; r != nil {
for _, a := range r.arcs {
if a.feature == label {
return &selectorExpr{newExpr(n),
&nodeRef{baseValue: newExpr(n), node: r}, label}
}
}
if v.inSelector > 0 {
if p := getBuiltinShorthandPkg(ctx, n.Name); p != nil {
return &nodeRef{baseValue: newExpr(n), node: p}
}
}
}
return nil
}
func (v *astVisitor) loadImport(imp *ast.ImportSpec) evaluated {
ctx := v.ctx()
path, err := literal.Unquote(imp.Path.Value)
if err != nil {
return v.errf(imp, "illformed import spec")
}
// TODO: allow builtin *and* imported package. The result is a unified
// struct.
if p := getBuiltinPkg(ctx, path); p != nil {
return p
}
bimp := v.inst.LookupImport(path)
if bimp == nil {
return v.errf(imp, "package %q not found", path)
}
impInst := v.index.loadInstance(bimp)
return impInst.rootValue.evalPartial(ctx)
}
// We probably don't need to call Walk.s
func (v *astVisitor) walk(astNode ast.Node) (value value) {
switch n := astNode.(type) {
case *ast.File:
obj := v.object
v1 := &astVisitor{
astState: v.astState,
object: obj,
}
for _, e := range n.Decls {
switch x := e.(type) {
case *ast.EmitDecl:
if v1.object.emit == nil {
v1.object.emit = v1.walk(x.Expr)
} else {
v1.object.emit = mkBin(v.ctx(), token.NoPos, opUnify, v1.object.emit, v1.walk(x.Expr))
}
default:
v1.walk(e)
}
}
value = obj
case *ast.ImportDecl:
for _, s := range n.Specs {
v.walk(s)
}
case *ast.ImportSpec:
val := v.loadImport(n)
if !isBottom(val) {
v.setScope(n, val.(*structLit))
}
case *ast.StructLit:
obj := v.mapScope(n).(*structLit)
v1 := &astVisitor{
astState: v.astState,
object: obj,
parent: v,
}
passDoc := len(n.Elts) == 1 && !n.Lbrace.IsValid() && v.doc != nil
if passDoc {
v1.doc = v.doc
}
for _, e := range n.Elts {
switch x := e.(type) {
case *ast.EmitDecl:
// Only allowed at top-level.
return v1.errf(x, "emitting values is only allowed at top level")
case *ast.Field, *ast.Alias:
v1.walk(e)
case *ast.ComprehensionDecl:
v1.walk(x)
}
}
if passDoc {
v.doc = v1.doc // signal usage of document back to parent.
}
value = obj
case *ast.ListLit:
v1 := &astVisitor{
astState: v.astState,
object: v.object,
parent: v,
}
arcs := []arc{}
for i, e := range n.Elts {
v1.sel = strconv.Itoa(i)
arcs = append(arcs, arc{feature: label(i), v: v1.walk(e)})
}
s := &structLit{baseValue: newExpr(n), arcs: arcs}
list := &list{baseValue: newExpr(n), elem: s}
list.initLit()
if n.Ellipsis != token.NoPos || n.Type != nil {
list.len = newBound(v.ctx(), list.baseValue, opGeq, intKind, list.len)
if n.Type != nil {
list.typ = v1.walk(n.Type)
}
}
value = list
case *ast.ComprehensionDecl:
yielder := &yield{baseValue: newExpr(n.Field.Value)}
fc := &fieldComprehension{
baseValue: newDecl(n),
clauses: wrapClauses(v, yielder, n.Clauses),
}
field := n.Field
switch x := field.Label.(type) {
case *ast.Interpolation:
v.sel = "?"
yielder.key = v.walk(x)
yielder.value = v.walk(field.Value)
case *ast.TemplateLabel:
v.sel = "*"
f := v.label(x.Ident.Name, true)
sig := &params{}
sig.add(f, &basicType{newNode(field.Label), stringKind})
template := &lambdaExpr{newExpr(field.Value), sig, nil}
v.setScope(field, template)
template.value = v.walk(field.Value)
yielder.value = template
fc.isTemplate = true
case *ast.BasicLit, *ast.Ident:
name, ok := ast.LabelName(x)
if !ok {
return v.errf(x, "invalid field name: %v", x)
}
// TODO: is this correct? Just for info, so not very important.
v.sel = name
// TODO: if the clauses do not contain a guard, we know that this
// field will always be added and we can move the comprehension one
// level down. This, in turn, has the advantage that it is more
// likely that the cross-reference limitation for field
// comprehensions is not violated. To ensure compatibility between
// implementations, though, we should relax the spec as well.
// The cross-reference rule is simple and this relaxation seems a
// bit more complex.
// TODO: for now we can also consider making this an error if
// the list of clauses does not contain if and make a suggestion
// to rewrite it.
if name != "" {
yielder.key = &stringLit{newNode(x), name, nil}
yielder.value = v.walk(field.Value)
}
default:
panic("cue: unknown label type")
}
// yielder.key = v.walk(n.Field.Label)
// yielder.value = v.walk(n.Field.Value)
v.object.comprehensions = append(v.object.comprehensions, fc)
case *ast.Field:
opt := n.Optional != token.NoPos
switch x := n.Label.(type) {
case *ast.Interpolation:
v.sel = "?"
yielder := &yield{baseValue: newNode(x)}
fc := &fieldComprehension{
baseValue: newDecl(n),
clauses: yielder,
}
yielder.key = v.walk(x)
yielder.value = v.walk(n.Value)
yielder.opt = opt
v.object.comprehensions = append(v.object.comprehensions, fc)
case *ast.TemplateLabel:
v.sel = "*"
f := v.label(x.Ident.Name, true)
sig := &params{}
sig.add(f, &basicType{newNode(n.Label), stringKind})
template := &lambdaExpr{newNode(n), sig, nil}
v.setScope(n, template)
template.value = v.walk(n.Value)
if v.object.template == nil {
v.object.template = template
} else {
v.object.template = mkBin(v.ctx(), token.NoPos, opUnify, v.object.template, template)
}
case *ast.BasicLit, *ast.Ident:
if internal.DropOptional && opt {
break
}
v.sel, _ = ast.LabelName(x)
attrs, err := createAttrs(v.ctx(), newNode(n), n.Attrs)
if err != nil {
return err
}
f, ok := v.nodeLabel(x)
if !ok {
return v.errf(n.Label, "invalid field name: %v", n.Label)
}
if f != 0 {
var leftOverDoc *docNode
for _, c := range n.Comments() {
if c.Position == 0 {
leftOverDoc = v.doc
v.doc = &docNode{n: n}
break
}
}
val := v.walk(n.Value)
v.object.insertValue(v.ctx(), f, opt, val, attrs, v.doc)
v.doc = leftOverDoc
}
default:
panic("cue: unknown label type")
}
case *ast.Alias:
// parsed verbatim at reference.
case *ast.ListComprehension:
yielder := &yield{baseValue: newExpr(n.Expr)}
lc := &listComprehension{
newExpr(n),
wrapClauses(v, yielder, n.Clauses),
}
// we don't support key for lists (yet?)
yielder.value = v.walk(n.Expr)
return lc
// Expressions
case *ast.Ident:
if n.Node == nil {
if value = v.resolve(n); value != nil {
break
}
switch n.Name {
case "_":
return &top{newExpr(n)}
case "string":
return &basicType{newExpr(n), stringKind}
case "bytes":
return &basicType{newExpr(n), bytesKind}
case "bool":
return &basicType{newExpr(n), boolKind}
case "int":
return &basicType{newExpr(n), intKind}
case "float":
return &basicType{newExpr(n), floatKind}
case "number":
return &basicType{newExpr(n), numKind}
case "duration":
return &basicType{newExpr(n), durationKind}
case "len":
return lenBuiltin
case "and":
return andBuiltin
case "or":
return orBuiltin
}
if r, ok := predefinedRanges[n.Name]; ok {
return r
}
value = v.errf(n, "reference %q not found", n.Name)
break
}
if a, ok := n.Node.(*ast.Alias); ok {
value = v.walk(a.Expr)
break
}
f := v.label(n.Name, true)
if n.Scope != nil {
n2 := v.mapScope(n.Scope)
if l, ok := n2.(*lambdaExpr); ok && len(l.params.arcs) == 1 {
f = 0
}
value = &nodeRef{baseValue: newExpr(n), node: n2}
value = &selectorExpr{newExpr(n), value, f}
} else {
n2 := v.mapScope(n.Node)
value = &nodeRef{baseValue: newExpr(n), node: n2}
}
case *ast.BottomLit:
// TODO: record inline comment.
value = &bottom{baseValue: newExpr(n), format: "from source"}
case *ast.BadDecl:
// nothing to do
case *ast.BadExpr:
value = v.errf(n, "invalid expression")
case *ast.BasicLit:
value = v.litParser.parse(n)
case *ast.Interpolation:
if len(n.Elts) == 0 {
return v.errf(n, "invalid interpolation")
}
first, ok1 := n.Elts[0].(*ast.BasicLit)
last, ok2 := n.Elts[len(n.Elts)-1].(*ast.BasicLit)
if !ok1 || !ok2 {
return v.errf(n, "invalid interpolation")
}
if len(n.Elts) == 1 {
value = v.walk(n.Elts[0])
break
}
lit := &interpolation{baseValue: newExpr(n), k: stringKind}
value = lit
info, prefixLen, _, err := literal.ParseQuotes(first.Value, last.Value)
if err != nil {
return v.errf(n, "invalid interpolation: %v", err)
}
prefix := ""
for i := 0; i < len(n.Elts); i += 2 {
l, ok := n.Elts[i].(*ast.BasicLit)
if !ok {
return v.errf(n, "invalid interpolation")
}
s := l.Value
if !strings.HasPrefix(s, prefix) {
return v.errf(l, "invalid interpolation: unmatched ')'")
}
s = l.Value[prefixLen:]
x := parseString(v.ctx(), l, info, s)
lit.parts = append(lit.parts, x)
if i+1 < len(n.Elts) {
lit.parts = append(lit.parts, v.walk(n.Elts[i+1]))
}
prefix = ")"
prefixLen = 1
}
case *ast.ParenExpr:
value = v.walk(n.X)
case *ast.SelectorExpr:
v.inSelector++
value = &selectorExpr{
newExpr(n),
v.walk(n.X),
v.label(n.Sel.Name, true),
}
v.inSelector--
case *ast.IndexExpr:
value = &indexExpr{newExpr(n), v.walk(n.X), v.walk(n.Index)}
case *ast.SliceExpr:
slice := &sliceExpr{baseValue: newExpr(n), x: v.walk(n.X)}
if n.Low != nil {
slice.lo = v.walk(n.Low)
}
if n.High != nil {
slice.hi = v.walk(n.High)
}
value = slice
case *ast.CallExpr:
call := &callExpr{baseValue: newExpr(n), x: v.walk(n.Fun)}
for _, a := range n.Args {
call.args = append(call.args, v.walk(a))
}
value = call
case *ast.UnaryExpr:
switch n.Op {
case token.NOT, token.ADD, token.SUB:
value = &unaryExpr{
newExpr(n),
tokenMap[n.Op],
v.walk(n.X),
}
case token.GEQ, token.GTR, token.LSS, token.LEQ,
token.NEQ, token.MAT, token.NMAT:
value = newBound(
v.ctx(),
newExpr(n),
tokenMap[n.Op],
topKind|nonGround,
v.walk(n.X),
)
case token.MUL:
return v.errf(n, "preference mark not allowed at this position")
default:
return v.errf(n, "unsupported unary operator %q", n.Op)
}
case *ast.BinaryExpr:
switch n.Op {
case token.OR:
d := &disjunction{baseValue: newExpr(n)}
v.addDisjunctionElem(d, n.X, false)
v.addDisjunctionElem(d, n.Y, false)
value = d
default:
value = updateBin(v.ctx(), &binaryExpr{
newExpr(n),
tokenMap[n.Op], // op
v.walk(n.X), // left
v.walk(n.Y), // right
})
}
case *ast.CommentGroup:
// Nothing to do for a free-floating comment group.
// nothing to do
// case *syntax.EmitDecl:
default:
// TODO: unhandled node.
// value = ctx.mkErr(n, "unknown node type %T", n)
panic(fmt.Sprintf("unimplemented %T", n))
}
return value
}
func (v *astVisitor) addDisjunctionElem(d *disjunction, n ast.Node, mark bool) {
switch x := n.(type) {
case *ast.BinaryExpr:
if x.Op == token.OR {
v.addDisjunctionElem(d, x.X, mark)
v.addDisjunctionElem(d, x.Y, mark)
return
}
case *ast.UnaryExpr:
if x.Op == token.MUL {
mark = true
n = x.X
}
d.hasDefaults = true
}
d.values = append(d.values, dValue{v.walk(n), mark})
}
func wrapClauses(v *astVisitor, y yielder, clauses []ast.Clause) yielder {
for _, c := range clauses {
if n, ok := c.(*ast.ForClause); ok {
params := &params{}
fn := &lambdaExpr{newExpr(n.Source), params, nil}
v.setScope(n, fn)
}
}
for i := len(clauses) - 1; i >= 0; i-- {
switch n := clauses[i].(type) {
case *ast.ForClause:
fn := v.mapScope(n).(*lambdaExpr)
fn.value = y
key := "_"
if n.Key != nil {
key = n.Key.Name
}
f := v.label(key, true)
fn.add(f, &basicType{newExpr(n.Key), stringKind | intKind})
f = v.label(n.Value.Name, true)
fn.add(f, &top{})
y = &feed{newExpr(n.Source), v.walk(n.Source), fn}
case *ast.IfClause:
y = &guard{newExpr(n.Condition), v.walk(n.Condition), y}
}
}
return y
}