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-rw-r--r--vendor/github.com/authzed/cel-go/parser/parser.go1011
1 files changed, 1011 insertions, 0 deletions
diff --git a/vendor/github.com/authzed/cel-go/parser/parser.go b/vendor/github.com/authzed/cel-go/parser/parser.go
new file mode 100644
index 0000000..b179926
--- /dev/null
+++ b/vendor/github.com/authzed/cel-go/parser/parser.go
@@ -0,0 +1,1011 @@
+// 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 parser declares an expression parser with support for macro
+// expansion.
+package parser
+
+import (
+ "fmt"
+ "regexp"
+ "strconv"
+ "strings"
+
+ antlr "github.com/antlr4-go/antlr/v4"
+
+ "github.com/authzed/cel-go/common"
+ "github.com/authzed/cel-go/common/ast"
+ "github.com/authzed/cel-go/common/operators"
+ "github.com/authzed/cel-go/common/runes"
+ "github.com/authzed/cel-go/common/types"
+ "github.com/authzed/cel-go/parser/gen"
+)
+
+// Parser encapsulates the context necessary to perform parsing for different expressions.
+type Parser struct {
+ options
+}
+
+// NewParser builds and returns a new Parser using the provided options.
+func NewParser(opts ...Option) (*Parser, error) {
+ p := &Parser{}
+ for _, opt := range opts {
+ if err := opt(&p.options); err != nil {
+ return nil, err
+ }
+ }
+ if p.errorReportingLimit == 0 {
+ p.errorReportingLimit = 100
+ }
+ if p.maxRecursionDepth == 0 {
+ p.maxRecursionDepth = 250
+ }
+ if p.maxRecursionDepth == -1 {
+ p.maxRecursionDepth = int((^uint(0)) >> 1)
+ }
+ if p.errorRecoveryTokenLookaheadLimit == 0 {
+ p.errorRecoveryTokenLookaheadLimit = 256
+ }
+ if p.errorRecoveryLimit == 0 {
+ p.errorRecoveryLimit = 30
+ }
+ if p.errorRecoveryLimit == -1 {
+ p.errorRecoveryLimit = int((^uint(0)) >> 1)
+ }
+ if p.expressionSizeCodePointLimit == 0 {
+ p.expressionSizeCodePointLimit = 100_000
+ }
+ if p.expressionSizeCodePointLimit == -1 {
+ p.expressionSizeCodePointLimit = int((^uint(0)) >> 1)
+ }
+ // Bool is false by default, so populateMacroCalls will be false by default
+ return p, nil
+}
+
+// mustNewParser does the work of NewParser and panics if an error occurs.
+//
+// This function is only intended for internal use and is for backwards compatibility in Parse and
+// ParseWithMacros, where we know the options will result in an error.
+func mustNewParser(opts ...Option) *Parser {
+ p, err := NewParser(opts...)
+ if err != nil {
+ panic(err)
+ }
+ return p
+}
+
+// Parse parses the expression represented by source and returns the result.
+func (p *Parser) Parse(source common.Source) (*ast.AST, *common.Errors) {
+ errs := common.NewErrors(source)
+ fac := ast.NewExprFactory()
+ impl := parser{
+ errors: &parseErrors{errs},
+ exprFactory: fac,
+ helper: newParserHelper(source, fac),
+ macros: p.macros,
+ maxRecursionDepth: p.maxRecursionDepth,
+ errorReportingLimit: p.errorReportingLimit,
+ errorRecoveryLimit: p.errorRecoveryLimit,
+ errorRecoveryLookaheadTokenLimit: p.errorRecoveryTokenLookaheadLimit,
+ populateMacroCalls: p.populateMacroCalls,
+ enableOptionalSyntax: p.enableOptionalSyntax,
+ enableVariadicOperatorASTs: p.enableVariadicOperatorASTs,
+ }
+ buf, ok := source.(runes.Buffer)
+ if !ok {
+ buf = runes.NewBuffer(source.Content())
+ }
+ var out ast.Expr
+ if buf.Len() > p.expressionSizeCodePointLimit {
+ out = impl.reportError(common.NoLocation,
+ "expression code point size exceeds limit: size: %d, limit %d",
+ buf.Len(), p.expressionSizeCodePointLimit)
+ } else {
+ out = impl.parse(buf, source.Description())
+ }
+ return ast.NewAST(out, impl.helper.getSourceInfo()), errs
+}
+
+// reservedIds are not legal to use as variables. We exclude them post-parse, as they *are* valid
+// field names for protos, and it would complicate the grammar to distinguish the cases.
+var reservedIds = map[string]struct{}{
+ "as": {},
+ "break": {},
+ "const": {},
+ "continue": {},
+ "else": {},
+ "false": {},
+ "for": {},
+ "function": {},
+ "if": {},
+ "import": {},
+ "in": {},
+ "let": {},
+ "loop": {},
+ "package": {},
+ "namespace": {},
+ "null": {},
+ "return": {},
+ "true": {},
+ "var": {},
+ "void": {},
+ "while": {},
+}
+
+// Parse converts a source input a parsed expression.
+// This function calls ParseWithMacros with AllMacros.
+//
+// Deprecated: Use NewParser().Parse() instead.
+func Parse(source common.Source) (*ast.AST, *common.Errors) {
+ return mustNewParser(Macros(AllMacros...)).Parse(source)
+}
+
+type recursionError struct {
+ message string
+}
+
+// Error implements error.
+func (re *recursionError) Error() string {
+ return re.message
+}
+
+var _ error = &recursionError{}
+
+type recursionListener struct {
+ maxDepth int
+ ruleTypeDepth map[int]*int
+}
+
+func (rl *recursionListener) VisitTerminal(node antlr.TerminalNode) {}
+
+func (rl *recursionListener) VisitErrorNode(node antlr.ErrorNode) {}
+
+func (rl *recursionListener) EnterEveryRule(ctx antlr.ParserRuleContext) {
+ if ctx == nil {
+ return
+ }
+ ruleIndex := ctx.GetRuleIndex()
+ depth, found := rl.ruleTypeDepth[ruleIndex]
+ if !found {
+ var counter = 1
+ rl.ruleTypeDepth[ruleIndex] = &counter
+ depth = &counter
+ } else {
+ *depth++
+ }
+ if *depth > rl.maxDepth {
+ panic(&recursionError{
+ message: fmt.Sprintf("expression recursion limit exceeded: %d", rl.maxDepth),
+ })
+ }
+}
+
+func (rl *recursionListener) ExitEveryRule(ctx antlr.ParserRuleContext) {
+ if ctx == nil {
+ return
+ }
+ ruleIndex := ctx.GetRuleIndex()
+ if depth, found := rl.ruleTypeDepth[ruleIndex]; found && *depth > 0 {
+ *depth--
+ }
+}
+
+var _ antlr.ParseTreeListener = &recursionListener{}
+
+type tooManyErrors struct {
+ errorReportingLimit int
+}
+
+func (t *tooManyErrors) Error() string {
+ return fmt.Sprintf("More than %d syntax errors", t.errorReportingLimit)
+}
+
+var _ error = &tooManyErrors{}
+
+type recoveryLimitError struct {
+ message string
+}
+
+// Error implements error.
+func (rl *recoveryLimitError) Error() string {
+ return rl.message
+}
+
+type lookaheadLimitError struct {
+ message string
+}
+
+func (ll *lookaheadLimitError) Error() string {
+ return ll.message
+}
+
+var _ error = &recoveryLimitError{}
+
+type recoveryLimitErrorStrategy struct {
+ *antlr.DefaultErrorStrategy
+ errorRecoveryLimit int
+ errorRecoveryTokenLookaheadLimit int
+ recoveryAttempts int
+}
+
+type lookaheadConsumer struct {
+ antlr.Parser
+ errorRecoveryTokenLookaheadLimit int
+ lookaheadAttempts int
+}
+
+func (lc *lookaheadConsumer) Consume() antlr.Token {
+ if lc.lookaheadAttempts >= lc.errorRecoveryTokenLookaheadLimit {
+ panic(&lookaheadLimitError{
+ message: fmt.Sprintf("error recovery token lookahead limit exceeded: %d", lc.errorRecoveryTokenLookaheadLimit),
+ })
+ }
+ lc.lookaheadAttempts++
+ return lc.Parser.Consume()
+}
+
+func (rl *recoveryLimitErrorStrategy) Recover(recognizer antlr.Parser, e antlr.RecognitionException) {
+ rl.checkAttempts(recognizer)
+ lc := &lookaheadConsumer{Parser: recognizer, errorRecoveryTokenLookaheadLimit: rl.errorRecoveryTokenLookaheadLimit}
+ rl.DefaultErrorStrategy.Recover(lc, e)
+}
+
+func (rl *recoveryLimitErrorStrategy) RecoverInline(recognizer antlr.Parser) antlr.Token {
+ rl.checkAttempts(recognizer)
+ lc := &lookaheadConsumer{Parser: recognizer, errorRecoveryTokenLookaheadLimit: rl.errorRecoveryTokenLookaheadLimit}
+ return rl.DefaultErrorStrategy.RecoverInline(lc)
+}
+
+func (rl *recoveryLimitErrorStrategy) checkAttempts(recognizer antlr.Parser) {
+ if rl.recoveryAttempts == rl.errorRecoveryLimit {
+ rl.recoveryAttempts++
+ msg := fmt.Sprintf("error recovery attempt limit exceeded: %d", rl.errorRecoveryLimit)
+ recognizer.NotifyErrorListeners(msg, nil, nil)
+ panic(&recoveryLimitError{
+ message: msg,
+ })
+ }
+ rl.recoveryAttempts++
+}
+
+var _ antlr.ErrorStrategy = &recoveryLimitErrorStrategy{}
+
+type parser struct {
+ gen.BaseCELVisitor
+ errors *parseErrors
+ exprFactory ast.ExprFactory
+ helper *parserHelper
+ macros map[string]Macro
+ recursionDepth int
+ errorReports int
+ maxRecursionDepth int
+ errorReportingLimit int
+ errorRecoveryLimit int
+ errorRecoveryLookaheadTokenLimit int
+ populateMacroCalls bool
+ enableOptionalSyntax bool
+ enableVariadicOperatorASTs bool
+}
+
+var _ gen.CELVisitor = (*parser)(nil)
+
+func (p *parser) parse(expr runes.Buffer, desc string) ast.Expr {
+ lexer := gen.NewCELLexer(newCharStream(expr, desc))
+ lexer.RemoveErrorListeners()
+ lexer.AddErrorListener(p)
+
+ prsr := gen.NewCELParser(antlr.NewCommonTokenStream(lexer, 0))
+ prsr.RemoveErrorListeners()
+
+ prsrListener := &recursionListener{
+ maxDepth: p.maxRecursionDepth,
+ ruleTypeDepth: map[int]*int{},
+ }
+
+ prsr.AddErrorListener(p)
+ prsr.AddParseListener(prsrListener)
+
+ prsr.SetErrorHandler(&recoveryLimitErrorStrategy{
+ DefaultErrorStrategy: antlr.NewDefaultErrorStrategy(),
+ errorRecoveryLimit: p.errorRecoveryLimit,
+ errorRecoveryTokenLookaheadLimit: p.errorRecoveryLookaheadTokenLimit,
+ })
+
+ defer func() {
+ if val := recover(); val != nil {
+ switch err := val.(type) {
+ case *lookaheadLimitError:
+ p.errors.internalError(err.Error())
+ case *recursionError:
+ p.errors.internalError(err.Error())
+ case *tooManyErrors:
+ // do nothing
+ case *recoveryLimitError:
+ // do nothing, listeners already notified and error reported.
+ default:
+ panic(val)
+ }
+ }
+ }()
+
+ return p.Visit(prsr.Start_()).(ast.Expr)
+}
+
+// Visitor implementations.
+func (p *parser) Visit(tree antlr.ParseTree) any {
+ t := unnest(tree)
+ switch tree := t.(type) {
+ case *gen.StartContext:
+ return p.VisitStart(tree)
+ case *gen.ExprContext:
+ p.checkAndIncrementRecursionDepth()
+ out := p.VisitExpr(tree)
+ p.decrementRecursionDepth()
+ return out
+ case *gen.ConditionalAndContext:
+ return p.VisitConditionalAnd(tree)
+ case *gen.ConditionalOrContext:
+ return p.VisitConditionalOr(tree)
+ case *gen.RelationContext:
+ p.checkAndIncrementRecursionDepth()
+ out := p.VisitRelation(tree)
+ p.decrementRecursionDepth()
+ return out
+ case *gen.CalcContext:
+ p.checkAndIncrementRecursionDepth()
+ out := p.VisitCalc(tree)
+ p.decrementRecursionDepth()
+ return out
+ case *gen.LogicalNotContext:
+ return p.VisitLogicalNot(tree)
+ case *gen.IdentOrGlobalCallContext:
+ return p.VisitIdentOrGlobalCall(tree)
+ case *gen.SelectContext:
+ p.checkAndIncrementRecursionDepth()
+ out := p.VisitSelect(tree)
+ p.decrementRecursionDepth()
+ return out
+ case *gen.MemberCallContext:
+ p.checkAndIncrementRecursionDepth()
+ out := p.VisitMemberCall(tree)
+ p.decrementRecursionDepth()
+ return out
+ case *gen.MapInitializerListContext:
+ return p.VisitMapInitializerList(tree)
+ case *gen.NegateContext:
+ return p.VisitNegate(tree)
+ case *gen.IndexContext:
+ p.checkAndIncrementRecursionDepth()
+ out := p.VisitIndex(tree)
+ p.decrementRecursionDepth()
+ return out
+ case *gen.UnaryContext:
+ return p.VisitUnary(tree)
+ case *gen.CreateListContext:
+ return p.VisitCreateList(tree)
+ case *gen.CreateMessageContext:
+ return p.VisitCreateMessage(tree)
+ case *gen.CreateStructContext:
+ return p.VisitCreateStruct(tree)
+ case *gen.IntContext:
+ return p.VisitInt(tree)
+ case *gen.UintContext:
+ return p.VisitUint(tree)
+ case *gen.DoubleContext:
+ return p.VisitDouble(tree)
+ case *gen.StringContext:
+ return p.VisitString(tree)
+ case *gen.BytesContext:
+ return p.VisitBytes(tree)
+ case *gen.BoolFalseContext:
+ return p.VisitBoolFalse(tree)
+ case *gen.BoolTrueContext:
+ return p.VisitBoolTrue(tree)
+ case *gen.NullContext:
+ return p.VisitNull(tree)
+ }
+
+ // Report at least one error if the parser reaches an unknown parse element.
+ // Typically, this happens if the parser has already encountered a syntax error elsewhere.
+ if p.errors.errorCount() == 0 {
+ txt := "<<nil>>"
+ if t != nil {
+ txt = fmt.Sprintf("<<%T>>", t)
+ }
+ return p.reportError(common.NoLocation, "unknown parse element encountered: %s", txt)
+ }
+ return p.helper.newExpr(common.NoLocation)
+
+}
+
+// Visit a parse tree produced by CELParser#start.
+func (p *parser) VisitStart(ctx *gen.StartContext) any {
+ return p.Visit(ctx.Expr())
+}
+
+// Visit a parse tree produced by CELParser#expr.
+func (p *parser) VisitExpr(ctx *gen.ExprContext) any {
+ result := p.Visit(ctx.GetE()).(ast.Expr)
+ if ctx.GetOp() == nil {
+ return result
+ }
+ opID := p.helper.id(ctx.GetOp())
+ ifTrue := p.Visit(ctx.GetE1()).(ast.Expr)
+ ifFalse := p.Visit(ctx.GetE2()).(ast.Expr)
+ return p.globalCallOrMacro(opID, operators.Conditional, result, ifTrue, ifFalse)
+}
+
+// Visit a parse tree produced by CELParser#conditionalOr.
+func (p *parser) VisitConditionalOr(ctx *gen.ConditionalOrContext) any {
+ result := p.Visit(ctx.GetE()).(ast.Expr)
+ l := p.newLogicManager(operators.LogicalOr, result)
+ rest := ctx.GetE1()
+ for i, op := range ctx.GetOps() {
+ if i >= len(rest) {
+ return p.reportError(ctx, "unexpected character, wanted '||'")
+ }
+ next := p.Visit(rest[i]).(ast.Expr)
+ opID := p.helper.id(op)
+ l.addTerm(opID, next)
+ }
+ return l.toExpr()
+}
+
+// Visit a parse tree produced by CELParser#conditionalAnd.
+func (p *parser) VisitConditionalAnd(ctx *gen.ConditionalAndContext) any {
+ result := p.Visit(ctx.GetE()).(ast.Expr)
+ l := p.newLogicManager(operators.LogicalAnd, result)
+ rest := ctx.GetE1()
+ for i, op := range ctx.GetOps() {
+ if i >= len(rest) {
+ return p.reportError(ctx, "unexpected character, wanted '&&'")
+ }
+ next := p.Visit(rest[i]).(ast.Expr)
+ opID := p.helper.id(op)
+ l.addTerm(opID, next)
+ }
+ return l.toExpr()
+}
+
+// Visit a parse tree produced by CELParser#relation.
+func (p *parser) VisitRelation(ctx *gen.RelationContext) any {
+ opText := ""
+ if ctx.GetOp() != nil {
+ opText = ctx.GetOp().GetText()
+ }
+ if op, found := operators.Find(opText); found {
+ lhs := p.Visit(ctx.Relation(0)).(ast.Expr)
+ opID := p.helper.id(ctx.GetOp())
+ rhs := p.Visit(ctx.Relation(1)).(ast.Expr)
+ return p.globalCallOrMacro(opID, op, lhs, rhs)
+ }
+ return p.reportError(ctx, "operator not found")
+}
+
+// Visit a parse tree produced by CELParser#calc.
+func (p *parser) VisitCalc(ctx *gen.CalcContext) any {
+ opText := ""
+ if ctx.GetOp() != nil {
+ opText = ctx.GetOp().GetText()
+ }
+ if op, found := operators.Find(opText); found {
+ lhs := p.Visit(ctx.Calc(0)).(ast.Expr)
+ opID := p.helper.id(ctx.GetOp())
+ rhs := p.Visit(ctx.Calc(1)).(ast.Expr)
+ return p.globalCallOrMacro(opID, op, lhs, rhs)
+ }
+ return p.reportError(ctx, "operator not found")
+}
+
+func (p *parser) VisitUnary(ctx *gen.UnaryContext) any {
+ return p.helper.newLiteralString(ctx, "<<error>>")
+}
+
+// Visit a parse tree produced by CELParser#LogicalNot.
+func (p *parser) VisitLogicalNot(ctx *gen.LogicalNotContext) any {
+ if len(ctx.GetOps())%2 == 0 {
+ return p.Visit(ctx.Member())
+ }
+ opID := p.helper.id(ctx.GetOps()[0])
+ target := p.Visit(ctx.Member()).(ast.Expr)
+ return p.globalCallOrMacro(opID, operators.LogicalNot, target)
+}
+
+func (p *parser) VisitNegate(ctx *gen.NegateContext) any {
+ if len(ctx.GetOps())%2 == 0 {
+ return p.Visit(ctx.Member())
+ }
+ opID := p.helper.id(ctx.GetOps()[0])
+ target := p.Visit(ctx.Member()).(ast.Expr)
+ return p.globalCallOrMacro(opID, operators.Negate, target)
+}
+
+// VisitSelect visits a parse tree produced by CELParser#Select.
+func (p *parser) VisitSelect(ctx *gen.SelectContext) any {
+ operand := p.Visit(ctx.Member()).(ast.Expr)
+ // Handle the error case where no valid identifier is specified.
+ if ctx.GetId() == nil || ctx.GetOp() == nil {
+ return p.helper.newExpr(ctx)
+ }
+ id := ctx.GetId().GetText()
+ if ctx.GetOpt() != nil {
+ if !p.enableOptionalSyntax {
+ return p.reportError(ctx.GetOp(), "unsupported syntax '.?'")
+ }
+ return p.helper.newGlobalCall(
+ ctx.GetOp(),
+ operators.OptSelect,
+ operand,
+ p.helper.newLiteralString(ctx.GetId(), id))
+ }
+ return p.helper.newSelect(ctx.GetOp(), operand, id)
+}
+
+// VisitMemberCall visits a parse tree produced by CELParser#MemberCall.
+func (p *parser) VisitMemberCall(ctx *gen.MemberCallContext) any {
+ operand := p.Visit(ctx.Member()).(ast.Expr)
+ // Handle the error case where no valid identifier is specified.
+ if ctx.GetId() == nil {
+ return p.helper.newExpr(ctx)
+ }
+ id := ctx.GetId().GetText()
+ opID := p.helper.id(ctx.GetOpen())
+ return p.receiverCallOrMacro(opID, id, operand, p.visitExprList(ctx.GetArgs())...)
+}
+
+// Visit a parse tree produced by CELParser#Index.
+func (p *parser) VisitIndex(ctx *gen.IndexContext) any {
+ target := p.Visit(ctx.Member()).(ast.Expr)
+ // Handle the error case where no valid identifier is specified.
+ if ctx.GetOp() == nil {
+ return p.helper.newExpr(ctx)
+ }
+ opID := p.helper.id(ctx.GetOp())
+ index := p.Visit(ctx.GetIndex()).(ast.Expr)
+ operator := operators.Index
+ if ctx.GetOpt() != nil {
+ if !p.enableOptionalSyntax {
+ return p.reportError(ctx.GetOp(), "unsupported syntax '[?'")
+ }
+ operator = operators.OptIndex
+ }
+ return p.globalCallOrMacro(opID, operator, target, index)
+}
+
+// Visit a parse tree produced by CELParser#CreateMessage.
+func (p *parser) VisitCreateMessage(ctx *gen.CreateMessageContext) any {
+ messageName := ""
+ for _, id := range ctx.GetIds() {
+ if len(messageName) != 0 {
+ messageName += "."
+ }
+ messageName += id.GetText()
+ }
+ if ctx.GetLeadingDot() != nil {
+ messageName = "." + messageName
+ }
+ objID := p.helper.id(ctx.GetOp())
+ entries := p.VisitIFieldInitializerList(ctx.GetEntries()).([]ast.EntryExpr)
+ return p.helper.newObject(objID, messageName, entries...)
+}
+
+// Visit a parse tree of field initializers.
+func (p *parser) VisitIFieldInitializerList(ctx gen.IFieldInitializerListContext) any {
+ if ctx == nil || ctx.GetFields() == nil {
+ // This is the result of a syntax error handled elswhere, return empty.
+ return []ast.EntryExpr{}
+ }
+
+ result := make([]ast.EntryExpr, len(ctx.GetFields()))
+ cols := ctx.GetCols()
+ vals := ctx.GetValues()
+ for i, f := range ctx.GetFields() {
+ if i >= len(cols) || i >= len(vals) {
+ // This is the result of a syntax error detected elsewhere.
+ return []ast.EntryExpr{}
+ }
+ initID := p.helper.id(cols[i])
+ optField := f.(*gen.OptFieldContext)
+ optional := optField.GetOpt() != nil
+ if !p.enableOptionalSyntax && optional {
+ p.reportError(optField, "unsupported syntax '?'")
+ continue
+ }
+ // The field may be empty due to a prior error.
+ id := optField.IDENTIFIER()
+ if id == nil {
+ return []ast.EntryExpr{}
+ }
+ fieldName := id.GetText()
+ value := p.Visit(vals[i]).(ast.Expr)
+ field := p.helper.newObjectField(initID, fieldName, value, optional)
+ result[i] = field
+ }
+ return result
+}
+
+// Visit a parse tree produced by CELParser#IdentOrGlobalCall.
+func (p *parser) VisitIdentOrGlobalCall(ctx *gen.IdentOrGlobalCallContext) any {
+ identName := ""
+ if ctx.GetLeadingDot() != nil {
+ identName = "."
+ }
+ // Handle the error case where no valid identifier is specified.
+ if ctx.GetId() == nil {
+ return p.helper.newExpr(ctx)
+ }
+ // Handle reserved identifiers.
+ id := ctx.GetId().GetText()
+ if _, ok := reservedIds[id]; ok {
+ return p.reportError(ctx, "reserved identifier: %s", id)
+ }
+ identName += id
+ if ctx.GetOp() != nil {
+ opID := p.helper.id(ctx.GetOp())
+ return p.globalCallOrMacro(opID, identName, p.visitExprList(ctx.GetArgs())...)
+ }
+ return p.helper.newIdent(ctx.GetId(), identName)
+}
+
+// Visit a parse tree produced by CELParser#CreateList.
+func (p *parser) VisitCreateList(ctx *gen.CreateListContext) any {
+ listID := p.helper.id(ctx.GetOp())
+ elems, optionals := p.visitListInit(ctx.GetElems())
+ return p.helper.newList(listID, elems, optionals...)
+}
+
+// Visit a parse tree produced by CELParser#CreateStruct.
+func (p *parser) VisitCreateStruct(ctx *gen.CreateStructContext) any {
+ structID := p.helper.id(ctx.GetOp())
+ entries := []ast.EntryExpr{}
+ if ctx.GetEntries() != nil {
+ entries = p.Visit(ctx.GetEntries()).([]ast.EntryExpr)
+ }
+ return p.helper.newMap(structID, entries...)
+}
+
+// Visit a parse tree produced by CELParser#mapInitializerList.
+func (p *parser) VisitMapInitializerList(ctx *gen.MapInitializerListContext) any {
+ if ctx == nil || ctx.GetKeys() == nil {
+ // This is the result of a syntax error handled elswhere, return empty.
+ return []ast.EntryExpr{}
+ }
+
+ result := make([]ast.EntryExpr, len(ctx.GetCols()))
+ keys := ctx.GetKeys()
+ vals := ctx.GetValues()
+ for i, col := range ctx.GetCols() {
+ colID := p.helper.id(col)
+ if i >= len(keys) || i >= len(vals) {
+ // This is the result of a syntax error detected elsewhere.
+ return []ast.EntryExpr{}
+ }
+ optKey := keys[i]
+ optional := optKey.GetOpt() != nil
+ if !p.enableOptionalSyntax && optional {
+ p.reportError(optKey, "unsupported syntax '?'")
+ continue
+ }
+ key := p.Visit(optKey.GetE()).(ast.Expr)
+ value := p.Visit(vals[i]).(ast.Expr)
+ entry := p.helper.newMapEntry(colID, key, value, optional)
+ result[i] = entry
+ }
+ return result
+}
+
+// Visit a parse tree produced by CELParser#Int.
+func (p *parser) VisitInt(ctx *gen.IntContext) any {
+ text := ctx.GetTok().GetText()
+ base := 10
+ if strings.HasPrefix(text, "0x") {
+ base = 16
+ text = text[2:]
+ }
+ if ctx.GetSign() != nil {
+ text = ctx.GetSign().GetText() + text
+ }
+ i, err := strconv.ParseInt(text, base, 64)
+ if err != nil {
+ return p.reportError(ctx, "invalid int literal")
+ }
+ return p.helper.newLiteralInt(ctx, i)
+}
+
+// Visit a parse tree produced by CELParser#Uint.
+func (p *parser) VisitUint(ctx *gen.UintContext) any {
+ text := ctx.GetTok().GetText()
+ // trim the 'u' designator included in the uint literal.
+ text = text[:len(text)-1]
+ base := 10
+ if strings.HasPrefix(text, "0x") {
+ base = 16
+ text = text[2:]
+ }
+ i, err := strconv.ParseUint(text, base, 64)
+ if err != nil {
+ return p.reportError(ctx, "invalid uint literal")
+ }
+ return p.helper.newLiteralUint(ctx, i)
+}
+
+// Visit a parse tree produced by CELParser#Double.
+func (p *parser) VisitDouble(ctx *gen.DoubleContext) any {
+ txt := ctx.GetTok().GetText()
+ if ctx.GetSign() != nil {
+ txt = ctx.GetSign().GetText() + txt
+ }
+ f, err := strconv.ParseFloat(txt, 64)
+ if err != nil {
+ return p.reportError(ctx, "invalid double literal")
+ }
+ return p.helper.newLiteralDouble(ctx, f)
+
+}
+
+// Visit a parse tree produced by CELParser#String.
+func (p *parser) VisitString(ctx *gen.StringContext) any {
+ s := p.unquote(ctx, ctx.GetText(), false)
+ return p.helper.newLiteralString(ctx, s)
+}
+
+// Visit a parse tree produced by CELParser#Bytes.
+func (p *parser) VisitBytes(ctx *gen.BytesContext) any {
+ b := []byte(p.unquote(ctx, ctx.GetTok().GetText()[1:], true))
+ return p.helper.newLiteralBytes(ctx, b)
+}
+
+// Visit a parse tree produced by CELParser#BoolTrue.
+func (p *parser) VisitBoolTrue(ctx *gen.BoolTrueContext) any {
+ return p.helper.newLiteralBool(ctx, true)
+}
+
+// Visit a parse tree produced by CELParser#BoolFalse.
+func (p *parser) VisitBoolFalse(ctx *gen.BoolFalseContext) any {
+ return p.helper.newLiteralBool(ctx, false)
+}
+
+// Visit a parse tree produced by CELParser#Null.
+func (p *parser) VisitNull(ctx *gen.NullContext) any {
+ return p.helper.exprFactory.NewLiteral(p.helper.newID(ctx), types.NullValue)
+}
+
+func (p *parser) visitExprList(ctx gen.IExprListContext) []ast.Expr {
+ if ctx == nil {
+ return []ast.Expr{}
+ }
+ return p.visitSlice(ctx.GetE())
+}
+
+func (p *parser) visitListInit(ctx gen.IListInitContext) ([]ast.Expr, []int32) {
+ if ctx == nil {
+ return []ast.Expr{}, []int32{}
+ }
+ elements := ctx.GetElems()
+ result := make([]ast.Expr, len(elements))
+ optionals := []int32{}
+ for i, e := range elements {
+ ex := p.Visit(e.GetE()).(ast.Expr)
+ if ex == nil {
+ return []ast.Expr{}, []int32{}
+ }
+ result[i] = ex
+ if e.GetOpt() != nil {
+ if !p.enableOptionalSyntax {
+ p.reportError(e.GetOpt(), "unsupported syntax '?'")
+ continue
+ }
+ optionals = append(optionals, int32(i))
+ }
+ }
+ return result, optionals
+}
+
+func (p *parser) visitSlice(expressions []gen.IExprContext) []ast.Expr {
+ if expressions == nil {
+ return []ast.Expr{}
+ }
+ result := make([]ast.Expr, len(expressions))
+ for i, e := range expressions {
+ ex := p.Visit(e).(ast.Expr)
+ result[i] = ex
+ }
+ return result
+}
+
+func (p *parser) unquote(ctx any, value string, isBytes bool) string {
+ text, err := unescape(value, isBytes)
+ if err != nil {
+ p.reportError(ctx, "%s", err.Error())
+ return value
+ }
+ return text
+}
+
+func (p *parser) newLogicManager(function string, term ast.Expr) *logicManager {
+ if p.enableVariadicOperatorASTs {
+ return newVariadicLogicManager(p.exprFactory, function, term)
+ }
+ return newBalancingLogicManager(p.exprFactory, function, term)
+}
+
+func (p *parser) reportError(ctx any, format string, args ...any) ast.Expr {
+ var location common.Location
+ err := p.helper.newExpr(ctx)
+ switch c := ctx.(type) {
+ case common.Location:
+ location = c
+ case antlr.Token, antlr.ParserRuleContext:
+ location = p.helper.getLocation(err.ID())
+ }
+ // Provide arguments to the report error.
+ p.errors.reportErrorAtID(err.ID(), location, format, args...)
+ return err
+}
+
+// ANTLR Parse listener implementations
+func (p *parser) SyntaxError(recognizer antlr.Recognizer, offendingSymbol any, line, column int, msg string, e antlr.RecognitionException) {
+ l := p.helper.source.NewLocation(line, column)
+ // Hack to keep existing error messages consistent with previous versions of CEL when a reserved word
+ // is used as an identifier. This behavior needs to be overhauled to provide consistent, normalized error
+ // messages out of ANTLR to prevent future breaking changes related to error message content.
+ if strings.Contains(msg, "no viable alternative") {
+ msg = reservedIdentifier.ReplaceAllString(msg, mismatchedReservedIdentifier)
+ }
+ // Ensure that no more than 100 syntax errors are reported as this will halt attempts to recover from a
+ // seriously broken expression.
+ if p.errorReports < p.errorReportingLimit {
+ p.errorReports++
+ p.errors.syntaxError(l, msg)
+ } else {
+ tme := &tooManyErrors{errorReportingLimit: p.errorReportingLimit}
+ p.errors.syntaxError(l, tme.Error())
+ panic(tme)
+ }
+}
+
+func (p *parser) ReportAmbiguity(recognizer antlr.Parser, dfa *antlr.DFA, startIndex, stopIndex int, exact bool, ambigAlts *antlr.BitSet, configs *antlr.ATNConfigSet) {
+ // Intentional
+}
+
+func (p *parser) ReportAttemptingFullContext(recognizer antlr.Parser, dfa *antlr.DFA, startIndex, stopIndex int, conflictingAlts *antlr.BitSet, configs *antlr.ATNConfigSet) {
+ // Intentional
+}
+
+func (p *parser) ReportContextSensitivity(recognizer antlr.Parser, dfa *antlr.DFA, startIndex, stopIndex, prediction int, configs *antlr.ATNConfigSet) {
+ // Intentional
+}
+
+func (p *parser) globalCallOrMacro(exprID int64, function string, args ...ast.Expr) ast.Expr {
+ if expr, found := p.expandMacro(exprID, function, nil, args...); found {
+ return expr
+ }
+ return p.helper.newGlobalCall(exprID, function, args...)
+}
+
+func (p *parser) receiverCallOrMacro(exprID int64, function string, target ast.Expr, args ...ast.Expr) ast.Expr {
+ if expr, found := p.expandMacro(exprID, function, target, args...); found {
+ return expr
+ }
+ return p.helper.newReceiverCall(exprID, function, target, args...)
+}
+
+func (p *parser) expandMacro(exprID int64, function string, target ast.Expr, args ...ast.Expr) (ast.Expr, bool) {
+ macro, found := p.macros[makeMacroKey(function, len(args), target != nil)]
+ if !found {
+ macro, found = p.macros[makeVarArgMacroKey(function, target != nil)]
+ if !found {
+ return nil, false
+ }
+ }
+ eh := exprHelperPool.Get().(*exprHelper)
+ defer exprHelperPool.Put(eh)
+ eh.parserHelper = p.helper
+ eh.id = exprID
+ expr, err := macro.Expander()(eh, target, args)
+ // An error indicates that the macro was matched, but the arguments were not well-formed.
+ if err != nil {
+ loc := err.Location
+ if loc == nil {
+ loc = p.helper.getLocation(exprID)
+ }
+ p.helper.deleteId(exprID)
+ return p.reportError(loc, err.Message), true
+ }
+ // A nil value from the macro indicates that the macro implementation decided that
+ // an expansion should not be performed.
+ if expr == nil {
+ return nil, false
+ }
+ if p.populateMacroCalls {
+ p.helper.addMacroCall(expr.ID(), function, target, args...)
+ }
+ p.helper.deleteId(exprID)
+ return expr, true
+}
+
+func (p *parser) checkAndIncrementRecursionDepth() {
+ p.recursionDepth++
+ if p.recursionDepth > p.maxRecursionDepth {
+ panic(&recursionError{message: "max recursion depth exceeded"})
+ }
+}
+
+func (p *parser) decrementRecursionDepth() {
+ p.recursionDepth--
+}
+
+// unnest traverses down the left-hand side of the parse graph until it encounters the first compound
+// parse node or the first leaf in the parse graph.
+func unnest(tree antlr.ParseTree) antlr.ParseTree {
+ for tree != nil {
+ switch t := tree.(type) {
+ case *gen.ExprContext:
+ // conditionalOr op='?' conditionalOr : expr
+ if t.GetOp() != nil {
+ return t
+ }
+ // conditionalOr
+ tree = t.GetE()
+ case *gen.ConditionalOrContext:
+ // conditionalAnd (ops=|| conditionalAnd)*
+ if t.GetOps() != nil && len(t.GetOps()) > 0 {
+ return t
+ }
+ // conditionalAnd
+ tree = t.GetE()
+ case *gen.ConditionalAndContext:
+ // relation (ops=&& relation)*
+ if t.GetOps() != nil && len(t.GetOps()) > 0 {
+ return t
+ }
+ // relation
+ tree = t.GetE()
+ case *gen.RelationContext:
+ // relation op relation
+ if t.GetOp() != nil {
+ return t
+ }
+ // calc
+ tree = t.Calc()
+ case *gen.CalcContext:
+ // calc op calc
+ if t.GetOp() != nil {
+ return t
+ }
+ // unary
+ tree = t.Unary()
+ case *gen.MemberExprContext:
+ // member expands to one of: primary, select, index, or create message
+ tree = t.Member()
+ case *gen.PrimaryExprContext:
+ // primary expands to one of identifier, nested, create list, create struct, literal
+ tree = t.Primary()
+ case *gen.NestedContext:
+ // contains a nested 'expr'
+ tree = t.GetE()
+ case *gen.ConstantLiteralContext:
+ // expands to a primitive literal
+ tree = t.Literal()
+ default:
+ return t
+ }
+ }
+ return tree
+}
+
+var (
+ reservedIdentifier = regexp.MustCompile("no viable alternative at input '.(true|false|null)'")
+ mismatchedReservedIdentifier = "mismatched input '$1' expecting IDENTIFIER"
+)
generated by cgit v1.2.3 (git 2.39.1) at 2026-02-02 13:08:31 +0000