ceph-csi/vendor/github.com/google/cel-go/checker/env.go
Madhu Rajanna ff3e84ad67 rebase: update kubernetes to 1.28.0 in main
updating kubernetes to 1.28.0
in the main repo.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>
2023-08-17 13:43:15 +00:00

437 lines
14 KiB
Go

// Copyright 2018 Google LLC
//
// 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 checker
import (
"fmt"
"strings"
"google.golang.org/protobuf/proto"
"github.com/google/cel-go/checker/decls"
"github.com/google/cel-go/common/containers"
"github.com/google/cel-go/common/overloads"
"github.com/google/cel-go/common/types"
"github.com/google/cel-go/common/types/pb"
"github.com/google/cel-go/common/types/ref"
"github.com/google/cel-go/parser"
exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
)
type aggregateLiteralElementType int
const (
dynElementType aggregateLiteralElementType = iota
homogenousElementType aggregateLiteralElementType = 1 << iota
)
var (
crossTypeNumericComparisonOverloads = map[string]struct{}{
// double <-> int | uint
overloads.LessDoubleInt64: {},
overloads.LessDoubleUint64: {},
overloads.LessEqualsDoubleInt64: {},
overloads.LessEqualsDoubleUint64: {},
overloads.GreaterDoubleInt64: {},
overloads.GreaterDoubleUint64: {},
overloads.GreaterEqualsDoubleInt64: {},
overloads.GreaterEqualsDoubleUint64: {},
// int <-> double | uint
overloads.LessInt64Double: {},
overloads.LessInt64Uint64: {},
overloads.LessEqualsInt64Double: {},
overloads.LessEqualsInt64Uint64: {},
overloads.GreaterInt64Double: {},
overloads.GreaterInt64Uint64: {},
overloads.GreaterEqualsInt64Double: {},
overloads.GreaterEqualsInt64Uint64: {},
// uint <-> double | int
overloads.LessUint64Double: {},
overloads.LessUint64Int64: {},
overloads.LessEqualsUint64Double: {},
overloads.LessEqualsUint64Int64: {},
overloads.GreaterUint64Double: {},
overloads.GreaterUint64Int64: {},
overloads.GreaterEqualsUint64Double: {},
overloads.GreaterEqualsUint64Int64: {},
}
)
// Env is the environment for type checking.
//
// The Env is comprised of a container, type provider, declarations, and other related objects
// which can be used to assist with type-checking.
type Env struct {
container *containers.Container
provider ref.TypeProvider
declarations *decls.Scopes
aggLitElemType aggregateLiteralElementType
filteredOverloadIDs map[string]struct{}
}
// NewEnv returns a new *Env with the given parameters.
func NewEnv(container *containers.Container, provider ref.TypeProvider, opts ...Option) (*Env, error) {
declarations := decls.NewScopes()
declarations.Push()
envOptions := &options{}
for _, opt := range opts {
if err := opt(envOptions); err != nil {
return nil, err
}
}
aggLitElemType := dynElementType
if envOptions.homogeneousAggregateLiterals {
aggLitElemType = homogenousElementType
}
filteredOverloadIDs := crossTypeNumericComparisonOverloads
if envOptions.crossTypeNumericComparisons {
filteredOverloadIDs = make(map[string]struct{})
}
if envOptions.validatedDeclarations != nil {
declarations = envOptions.validatedDeclarations.Copy()
}
return &Env{
container: container,
provider: provider,
declarations: declarations,
aggLitElemType: aggLitElemType,
filteredOverloadIDs: filteredOverloadIDs,
}, nil
}
// Add adds new Decl protos to the Env.
// Returns an error for identifier redeclarations.
func (e *Env) Add(decls ...*exprpb.Decl) error {
errMsgs := make([]errorMsg, 0)
for _, decl := range decls {
switch decl.DeclKind.(type) {
case *exprpb.Decl_Ident:
errMsgs = append(errMsgs, e.addIdent(sanitizeIdent(decl)))
case *exprpb.Decl_Function:
errMsgs = append(errMsgs, e.setFunction(sanitizeFunction(decl))...)
}
}
return formatError(errMsgs)
}
// LookupIdent returns a Decl proto for typeName as an identifier in the Env.
// Returns nil if no such identifier is found in the Env.
func (e *Env) LookupIdent(name string) *exprpb.Decl {
for _, candidate := range e.container.ResolveCandidateNames(name) {
if ident := e.declarations.FindIdent(candidate); ident != nil {
return ident
}
// Next try to import the name as a reference to a message type. If found,
// the declaration is added to the outest (global) scope of the
// environment, so next time we can access it faster.
if t, found := e.provider.FindType(candidate); found {
decl := decls.NewVar(candidate, t)
e.declarations.AddIdent(decl)
return decl
}
// Next try to import this as an enum value by splitting the name in a type prefix and
// the enum inside.
if enumValue := e.provider.EnumValue(candidate); enumValue.Type() != types.ErrType {
decl := decls.NewIdent(candidate,
decls.Int,
&exprpb.Constant{
ConstantKind: &exprpb.Constant_Int64Value{
Int64Value: int64(enumValue.(types.Int))}})
e.declarations.AddIdent(decl)
return decl
}
}
return nil
}
// LookupFunction returns a Decl proto for typeName as a function in env.
// Returns nil if no such function is found in env.
func (e *Env) LookupFunction(name string) *exprpb.Decl {
for _, candidate := range e.container.ResolveCandidateNames(name) {
if fn := e.declarations.FindFunction(candidate); fn != nil {
return fn
}
}
return nil
}
// addOverload adds overload to function declaration f.
// Returns one or more errorMsg values if the overload overlaps with an existing overload or macro.
func (e *Env) addOverload(f *exprpb.Decl, overload *exprpb.Decl_FunctionDecl_Overload) []errorMsg {
errMsgs := make([]errorMsg, 0)
function := f.GetFunction()
emptyMappings := newMapping()
overloadFunction := decls.NewFunctionType(overload.GetResultType(),
overload.GetParams()...)
overloadErased := substitute(emptyMappings, overloadFunction, true)
for _, existing := range function.GetOverloads() {
existingFunction := decls.NewFunctionType(existing.GetResultType(), existing.GetParams()...)
existingErased := substitute(emptyMappings, existingFunction, true)
overlap := isAssignable(emptyMappings, overloadErased, existingErased) != nil ||
isAssignable(emptyMappings, existingErased, overloadErased) != nil
if overlap &&
overload.GetIsInstanceFunction() == existing.GetIsInstanceFunction() {
errMsgs = append(errMsgs,
overlappingOverloadError(f.Name,
overload.GetOverloadId(), overloadFunction,
existing.GetOverloadId(), existingFunction))
}
}
for _, macro := range parser.AllMacros {
if macro.Function() == f.Name &&
macro.IsReceiverStyle() == overload.GetIsInstanceFunction() &&
macro.ArgCount() == len(overload.GetParams()) {
errMsgs = append(errMsgs, overlappingMacroError(f.Name, macro.ArgCount()))
}
}
if len(errMsgs) > 0 {
return errMsgs
}
function.Overloads = append(function.GetOverloads(), overload)
return errMsgs
}
// setFunction adds the function Decl to the Env.
// Adds a function decl if one doesn't already exist, then adds all overloads from the Decl.
// If overload overlaps with an existing overload, adds to the errors in the Env instead.
func (e *Env) setFunction(decl *exprpb.Decl) []errorMsg {
errorMsgs := make([]errorMsg, 0)
overloads := decl.GetFunction().GetOverloads()
current := e.declarations.FindFunction(decl.Name)
if current == nil {
//Add the function declaration without overloads and check the overloads below.
current = decls.NewFunction(decl.Name)
} else {
existingOverloads := map[string]*exprpb.Decl_FunctionDecl_Overload{}
for _, overload := range current.GetFunction().GetOverloads() {
existingOverloads[overload.GetOverloadId()] = overload
}
newOverloads := []*exprpb.Decl_FunctionDecl_Overload{}
for _, overload := range overloads {
existing, found := existingOverloads[overload.GetOverloadId()]
if !found || !overloadsEqual(existing, overload) {
newOverloads = append(newOverloads, overload)
}
}
overloads = newOverloads
if len(newOverloads) == 0 {
return errorMsgs
}
// Copy on write since we don't know where this original definition came from.
current = proto.Clone(current).(*exprpb.Decl)
}
e.declarations.SetFunction(current)
for _, overload := range overloads {
errorMsgs = append(errorMsgs, e.addOverload(current, overload)...)
}
return errorMsgs
}
// addIdent adds the Decl to the declarations in the Env.
// Returns a non-empty errorMsg if the identifier is already declared in the scope.
func (e *Env) addIdent(decl *exprpb.Decl) errorMsg {
current := e.declarations.FindIdentInScope(decl.Name)
if current != nil {
if proto.Equal(current, decl) {
return ""
}
return overlappingIdentifierError(decl.Name)
}
e.declarations.AddIdent(decl)
return ""
}
// isOverloadDisabled returns whether the overloadID is disabled in the current environment.
func (e *Env) isOverloadDisabled(overloadID string) bool {
_, found := e.filteredOverloadIDs[overloadID]
return found
}
// overloadsEqual returns whether two overloads have identical signatures.
//
// type parameter names are ignored as they may be specified in any order and have no bearing on overload
// equivalence
func overloadsEqual(o1, o2 *exprpb.Decl_FunctionDecl_Overload) bool {
return o1.GetOverloadId() == o2.GetOverloadId() &&
o1.GetIsInstanceFunction() == o2.GetIsInstanceFunction() &&
paramsEqual(o1.GetParams(), o2.GetParams()) &&
proto.Equal(o1.GetResultType(), o2.GetResultType())
}
// paramsEqual returns whether two lists have equal length and all types are equal
func paramsEqual(p1, p2 []*exprpb.Type) bool {
if len(p1) != len(p2) {
return false
}
for i, a := range p1 {
b := p2[i]
if !proto.Equal(a, b) {
return false
}
}
return true
}
// sanitizeFunction replaces well-known types referenced by message name with their equivalent
// CEL built-in type instances.
func sanitizeFunction(decl *exprpb.Decl) *exprpb.Decl {
fn := decl.GetFunction()
// Determine whether the declaration requires replacements from proto-based message type
// references to well-known CEL type references.
var needsSanitizing bool
for _, o := range fn.GetOverloads() {
if isObjectWellKnownType(o.GetResultType()) {
needsSanitizing = true
break
}
for _, p := range o.GetParams() {
if isObjectWellKnownType(p) {
needsSanitizing = true
break
}
}
}
// Early return if the declaration requires no modification.
if !needsSanitizing {
return decl
}
// Sanitize all of the overloads if any overload requires an update to its type references.
overloads := make([]*exprpb.Decl_FunctionDecl_Overload, len(fn.GetOverloads()))
for i, o := range fn.GetOverloads() {
rt := o.GetResultType()
if isObjectWellKnownType(rt) {
rt = getObjectWellKnownType(rt)
}
params := make([]*exprpb.Type, len(o.GetParams()))
copy(params, o.GetParams())
for j, p := range params {
if isObjectWellKnownType(p) {
params[j] = getObjectWellKnownType(p)
}
}
// If sanitized, replace the overload definition.
if o.IsInstanceFunction {
overloads[i] =
decls.NewInstanceOverload(o.GetOverloadId(), params, rt)
} else {
overloads[i] =
decls.NewOverload(o.GetOverloadId(), params, rt)
}
}
return decls.NewFunction(decl.GetName(), overloads...)
}
// sanitizeIdent replaces the identifier's well-known types referenced by message name with
// references to CEL built-in type instances.
func sanitizeIdent(decl *exprpb.Decl) *exprpb.Decl {
id := decl.GetIdent()
t := id.GetType()
if !isObjectWellKnownType(t) {
return decl
}
return decls.NewIdent(decl.GetName(), getObjectWellKnownType(t), id.GetValue())
}
// isObjectWellKnownType returns true if the input type is an OBJECT type with a message name
// that corresponds the message name of a built-in CEL type.
func isObjectWellKnownType(t *exprpb.Type) bool {
if kindOf(t) != kindObject {
return false
}
_, found := pb.CheckedWellKnowns[t.GetMessageType()]
return found
}
// getObjectWellKnownType returns the built-in CEL type declaration for input type's message name.
func getObjectWellKnownType(t *exprpb.Type) *exprpb.Type {
return pb.CheckedWellKnowns[t.GetMessageType()]
}
// validatedDeclarations returns a reference to the validated variable and function declaration scope stack.
// must be copied before use.
func (e *Env) validatedDeclarations() *decls.Scopes {
return e.declarations
}
// enterScope creates a new Env instance with a new innermost declaration scope.
func (e *Env) enterScope() *Env {
childDecls := e.declarations.Push()
return &Env{
declarations: childDecls,
container: e.container,
provider: e.provider,
aggLitElemType: e.aggLitElemType,
}
}
// exitScope creates a new Env instance with the nearest outer declaration scope.
func (e *Env) exitScope() *Env {
parentDecls := e.declarations.Pop()
return &Env{
declarations: parentDecls,
container: e.container,
provider: e.provider,
aggLitElemType: e.aggLitElemType,
}
}
// errorMsg is a type alias meant to represent error-based return values which
// may be accumulated into an error at a later point in execution.
type errorMsg string
func overlappingIdentifierError(name string) errorMsg {
return errorMsg(fmt.Sprintf("overlapping identifier for name '%s'", name))
}
func overlappingOverloadError(name string,
overloadID1 string, f1 *exprpb.Type,
overloadID2 string, f2 *exprpb.Type) errorMsg {
return errorMsg(fmt.Sprintf(
"overlapping overload for name '%s' (type '%s' with overloadId: '%s' "+
"cannot be distinguished from '%s' with overloadId: '%s')",
name,
FormatCheckedType(f1),
overloadID1,
FormatCheckedType(f2),
overloadID2))
}
func overlappingMacroError(name string, argCount int) errorMsg {
return errorMsg(fmt.Sprintf(
"overlapping macro for name '%s' with %d args", name, argCount))
}
func formatError(errMsgs []errorMsg) error {
errStrs := make([]string, 0)
if len(errMsgs) > 0 {
for i := 0; i < len(errMsgs); i++ {
if errMsgs[i] != "" {
errStrs = append(errStrs, string(errMsgs[i]))
}
}
}
if len(errStrs) > 0 {
return fmt.Errorf("%s", strings.Join(errStrs, "\n"))
}
return nil
}