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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef vm_JSONParser_h
+#define vm_JSONParser_h
+
+#include "mozilla/Assertions.h" // MOZ_ASSERT
+#include "mozilla/Attributes.h" // MOZ_STACK_CLASS
+#include "mozilla/Range.h" // mozilla::Range
+#include "mozilla/RangedPtr.h" // mozilla::RangedPtr
+
+#include <stddef.h> // size_t
+#include <stdint.h> // uint32_t
+#include <utility> // std::move
+
+#include "builtin/ParseRecordObject.h" // js::ParseRecordObject
+#include "ds/IdValuePair.h" // IdValuePair
+#include "gc/GC.h" // AutoSelectGCHeap
+#include "js/GCVector.h" // JS::GCVector
+#include "js/RootingAPI.h" // JS::Handle, JS::MutableHandle, MutableWrappedPtrOperations
+#include "js/Value.h" // JS::Value, JS::BooleanValue, JS::NullValue
+#include "js/Vector.h" // Vector
+#include "util/StringBuffer.h" // JSStringBuilder
+#include "vm/StringType.h" // JSString, JSAtom
+
+struct JSContext;
+class JSTracer;
+
+namespace js {
+
+class FrontendContext;
+
+enum class JSONToken {
+ String,
+ Number,
+ True,
+ False,
+ Null,
+ ArrayOpen,
+ ArrayClose,
+ ObjectOpen,
+ ObjectClose,
+ Colon,
+ Comma,
+ OOM,
+ Error
+};
+
+enum class JSONStringType { PropertyName, LiteralValue };
+
+template <typename CharT, typename ParserT, typename StringBuilderT>
+class MOZ_STACK_CLASS JSONTokenizer {
+ public:
+ using CharPtr = mozilla::RangedPtr<const CharT>;
+
+ protected:
+ CharPtr sourceStart;
+ CharPtr current;
+ const CharPtr begin, end;
+
+ ParserT* parser = nullptr;
+
+ JSONTokenizer(CharPtr sourceStart, CharPtr current, const CharPtr begin,
+ const CharPtr end, ParserT* parser)
+ : sourceStart(sourceStart),
+ current(current),
+ begin(begin),
+ end(end),
+ parser(parser) {
+ MOZ_ASSERT(current <= end);
+ MOZ_ASSERT(parser);
+ }
+
+ public:
+ JSONTokenizer(CharPtr current, const CharPtr begin, const CharPtr end,
+ ParserT* parser)
+ : JSONTokenizer(current, current, begin, end, parser) {}
+
+ explicit JSONTokenizer(mozilla::Range<const CharT> data, ParserT* parser)
+ : JSONTokenizer(data.begin(), data.begin(), data.end(), parser) {}
+
+ JSONTokenizer(JSONTokenizer<CharT, ParserT, StringBuilderT>&& other) noexcept
+ : JSONTokenizer(other.sourceStart, other.current, other.begin, other.end,
+ other.parser) {}
+
+ JSONTokenizer(const JSONTokenizer<CharT, ParserT, StringBuilderT>& other) =
+ delete;
+ void operator=(const JSONTokenizer<CharT, ParserT, StringBuilderT>& other) =
+ delete;
+
+ void fixupParser(ParserT* newParser) { parser = newParser; }
+
+ void getTextPosition(uint32_t* column, uint32_t* line);
+
+ bool consumeTrailingWhitespaces();
+
+ JSONToken advance();
+ JSONToken advancePropertyName();
+ JSONToken advancePropertyColon();
+ JSONToken advanceAfterProperty();
+ JSONToken advanceAfterObjectOpen();
+ JSONToken advanceAfterArrayElement();
+
+ void unget() { --current; }
+
+#ifdef DEBUG
+ bool finished() { return end == current; }
+#endif
+
+ JSONToken token(JSONToken t) {
+ MOZ_ASSERT(t != JSONToken::String);
+ MOZ_ASSERT(t != JSONToken::Number);
+ return t;
+ }
+
+ template <JSONStringType ST>
+ JSONToken stringToken(const CharPtr start, size_t length);
+ template <JSONStringType ST>
+ JSONToken stringToken(StringBuilderT& builder);
+
+ JSONToken numberToken(double d);
+
+ template <JSONStringType ST>
+ JSONToken readString();
+
+ JSONToken readNumber();
+
+ void error(const char* msg);
+
+ protected:
+ inline mozilla::Span<const CharT> getSource() const {
+ return mozilla::Span<const CharT>(sourceStart.get(), current.get());
+ }
+};
+
+// Possible states the parser can be in between values.
+enum class JSONParserState {
+ // An array element has just being parsed.
+ FinishArrayElement,
+
+ // An object property has just been parsed.
+ FinishObjectMember,
+
+ // At the start of the parse, before any values have been processed.
+ JSONValue
+};
+
+// Character-type-agnostic base class for JSONFullParseHandler.
+// JSONParser is templatized to work on either Latin1
+// or TwoByte input strings, JSONFullParseHandlerAnyChar holds all state and
+// methods that can be shared between the two encodings.
+class MOZ_STACK_CLASS JSONFullParseHandlerAnyChar {
+ public:
+ // State related to the parser's current position. At all points in the
+ // parse this keeps track of the stack of arrays and objects which have
+ // been started but not finished yet. The actual JS object is not
+ // allocated until the literal is closed, so that the result can be sized
+ // according to its contents and have its type and shape filled in using
+ // caches.
+
+ // State for an array that is currently being parsed. This includes all
+ // elements that have been seen so far.
+ using ElementVector = JS::GCVector<JS::Value, 20>;
+
+ // State for an object that is currently being parsed. This includes all
+ // the key/value pairs that have been seen so far.
+ using PropertyVector = JS::GCVector<IdValuePair, 10>;
+
+ enum class ParseType {
+ // Parsing a string as if by JSON.parse.
+ JSONParse,
+ // Parsing what may or may not be JSON in a string of eval code.
+ // In this case, a failure to parse indicates either syntax that isn't JSON,
+ // or syntax that has different semantics in eval code than in JSON.
+ AttemptForEval,
+ };
+
+ // Stack element for an in progress array or object.
+ struct StackEntry {
+ ElementVector& elements() {
+ MOZ_ASSERT(state == JSONParserState::FinishArrayElement);
+ return *static_cast<ElementVector*>(vector);
+ }
+
+ PropertyVector& properties() {
+ MOZ_ASSERT(state == JSONParserState::FinishObjectMember);
+ return *static_cast<PropertyVector*>(vector);
+ }
+
+ explicit StackEntry(ElementVector* elements)
+ : state(JSONParserState::FinishArrayElement), vector(elements) {}
+
+ explicit StackEntry(PropertyVector* properties)
+ : state(JSONParserState::FinishObjectMember), vector(properties) {}
+
+ JSONParserState state;
+
+ private:
+ void* vector;
+ };
+
+ public:
+ /* Data members */
+
+ JSContext* cx;
+
+ JS::Value v;
+
+ ParseType parseType = ParseType::JSONParse;
+
+ AutoSelectGCHeap gcHeap;
+
+ private:
+ // Unused element and property vectors for previous in progress arrays and
+ // objects. These vectors are not freed until the end of the parse to avoid
+ // unnecessary freeing and allocation.
+ Vector<ElementVector*, 5> freeElements;
+ Vector<PropertyVector*, 5> freeProperties;
+
+ public:
+ explicit JSONFullParseHandlerAnyChar(JSContext* cx);
+ ~JSONFullParseHandlerAnyChar();
+
+ // Allow move construction for use with Rooted.
+ JSONFullParseHandlerAnyChar(JSONFullParseHandlerAnyChar&& other) noexcept;
+
+ JSONFullParseHandlerAnyChar(const JSONFullParseHandlerAnyChar& other) =
+ delete;
+ void operator=(const JSONFullParseHandlerAnyChar& other) = delete;
+
+ JSContext* context() { return cx; }
+
+ JS::Value numberValue() const {
+ MOZ_ASSERT(v.isNumber());
+ return v;
+ }
+
+ JS::Value stringValue() const {
+ MOZ_ASSERT(v.isString());
+ return v;
+ }
+
+ JSAtom* atomValue() const {
+ JS::Value strval = stringValue();
+ return &strval.toString()->asAtom();
+ }
+
+ inline JS::Value booleanValue(bool value) { return JS::BooleanValue(value); }
+ inline JS::Value nullValue() { return JS::NullValue(); }
+
+ inline bool objectOpen(Vector<StackEntry, 10>& stack,
+ PropertyVector** properties);
+ inline bool objectPropertyName(Vector<StackEntry, 10>& stack,
+ bool* isProtoInEval);
+ inline void finishObjectMember(Vector<StackEntry, 10>& stack,
+ JS::Handle<JS::Value> value,
+ PropertyVector** properties);
+ inline bool finishObject(Vector<StackEntry, 10>& stack,
+ JS::MutableHandle<JS::Value> vp,
+ PropertyVector* properties);
+
+ inline bool arrayOpen(Vector<StackEntry, 10>& stack,
+ ElementVector** elements);
+ inline bool arrayElement(Vector<StackEntry, 10>& stack,
+ JS::Handle<JS::Value> value,
+ ElementVector** elements);
+ inline bool finishArray(Vector<StackEntry, 10>& stack,
+ JS::MutableHandle<JS::Value> vp,
+ ElementVector* elements);
+
+ inline bool errorReturn() const {
+ return parseType == ParseType::AttemptForEval;
+ }
+
+ inline bool ignoreError() const {
+ return parseType == ParseType::AttemptForEval;
+ }
+
+ inline void freeStackEntry(StackEntry& entry);
+
+ void trace(JSTracer* trc);
+};
+
+template <typename CharT>
+class MOZ_STACK_CLASS JSONFullParseHandler
+ : public JSONFullParseHandlerAnyChar {
+ using Base = JSONFullParseHandlerAnyChar;
+ using CharPtr = mozilla::RangedPtr<const CharT>;
+
+ public:
+ using ContextT = JSContext;
+
+ class StringBuilder {
+ public:
+ JSStringBuilder buffer;
+
+ explicit StringBuilder(JSContext* cx) : buffer(cx) {}
+
+ bool append(char16_t c);
+ bool append(const CharT* begin, const CharT* end);
+ };
+
+ ParseRecordObject parseRecord;
+
+ explicit JSONFullParseHandler(JSContext* cx) : Base(cx) {}
+
+ JSONFullParseHandler(JSONFullParseHandler&& other) noexcept
+ : Base(std::move(other)) {}
+
+ JSONFullParseHandler(const JSONFullParseHandler& other) = delete;
+ void operator=(const JSONFullParseHandler& other) = delete;
+
+ template <JSONStringType ST>
+ inline bool setStringValue(CharPtr start, size_t length,
+ mozilla::Span<const CharT>&& source);
+ template <JSONStringType ST>
+ inline bool setStringValue(StringBuilder& builder,
+ mozilla::Span<const CharT>&& source);
+ inline bool setNumberValue(double d, mozilla::Span<const CharT>&& source);
+ inline bool setBooleanValue(bool value, mozilla::Span<const CharT>&& source);
+ inline bool setNullValue(mozilla::Span<const CharT>&& source);
+
+ void reportError(const char* msg, uint32_t line, uint32_t column);
+
+ void trace(JSTracer* trc);
+
+ protected:
+ inline bool createJSONParseRecord(const Value& value,
+ mozilla::Span<const CharT>& source);
+};
+
+template <typename CharT>
+class MOZ_STACK_CLASS JSONSyntaxParseHandler {
+ private:
+ using CharPtr = mozilla::RangedPtr<const CharT>;
+
+ public:
+ /* Types for templatized parser. */
+
+ using ContextT = FrontendContext;
+
+ class DummyValue {};
+
+ struct ElementVector {};
+ struct PropertyVector {};
+
+ class StringBuilder {
+ public:
+ explicit StringBuilder(FrontendContext* fc) {}
+
+ bool append(char16_t c) { return true; }
+ bool append(const CharT* begin, const CharT* end) { return true; }
+ };
+
+ struct StackEntry {
+ JSONParserState state;
+ };
+
+ public:
+ FrontendContext* fc;
+
+ /* Public API */
+
+ /* Create a parser for the provided JSON data. */
+ explicit JSONSyntaxParseHandler(FrontendContext* fc) : fc(fc) {}
+
+ JSONSyntaxParseHandler(JSONSyntaxParseHandler&& other) noexcept
+ : fc(other.fc) {}
+
+ JSONSyntaxParseHandler(const JSONSyntaxParseHandler& other) = delete;
+ void operator=(const JSONSyntaxParseHandler& other) = delete;
+
+ FrontendContext* context() { return fc; }
+
+ template <JSONStringType ST>
+ inline bool setStringValue(CharPtr start, size_t length,
+ mozilla::Span<const CharT>&& source) {
+ return true;
+ }
+
+ template <JSONStringType ST>
+ inline bool setStringValue(StringBuilder& builder,
+ mozilla::Span<const CharT>&& source) {
+ return true;
+ }
+
+ inline bool setNumberValue(double d, mozilla::Span<const CharT>&& source) {
+ return true;
+ }
+ inline bool setBooleanValue(bool value, mozilla::Span<const CharT>&& source) {
+ return true;
+ }
+ inline bool setNullValue(mozilla::Span<const CharT>&& source) { return true; }
+
+ inline DummyValue numberValue() const { return DummyValue(); }
+
+ inline DummyValue stringValue() const { return DummyValue(); }
+
+ inline DummyValue booleanValue(bool value) { return DummyValue(); }
+ inline DummyValue nullValue() { return DummyValue(); }
+
+ inline bool objectOpen(Vector<StackEntry, 10>& stack,
+ PropertyVector** properties);
+ inline bool objectPropertyName(Vector<StackEntry, 10>& stack,
+ bool* isProtoInEval) {
+ *isProtoInEval = false;
+ return true;
+ }
+ inline void finishObjectMember(Vector<StackEntry, 10>& stack,
+ DummyValue& value,
+ PropertyVector** properties) {}
+ inline bool finishObject(Vector<StackEntry, 10>& stack, DummyValue* vp,
+ PropertyVector* properties);
+
+ inline bool arrayOpen(Vector<StackEntry, 10>& stack,
+ ElementVector** elements);
+ inline bool arrayElement(Vector<StackEntry, 10>& stack, DummyValue& value,
+ ElementVector** elements) {
+ return true;
+ }
+ inline bool finishArray(Vector<StackEntry, 10>& stack, DummyValue* vp,
+ ElementVector* elements);
+
+ inline bool errorReturn() const { return false; }
+
+ inline bool ignoreError() const { return false; }
+
+ inline void freeStackEntry(StackEntry& entry) {}
+
+ void reportError(const char* msg, uint32_t line, uint32_t column);
+};
+
+template <typename CharT, typename HandlerT>
+class MOZ_STACK_CLASS JSONPerHandlerParser {
+ using ContextT = typename HandlerT::ContextT;
+
+ using Tokenizer = JSONTokenizer<CharT, JSONPerHandlerParser<CharT, HandlerT>,
+ typename HandlerT::StringBuilder>;
+
+ public:
+ using StringBuilder = typename HandlerT::StringBuilder;
+
+ public:
+ HandlerT handler;
+ Tokenizer tokenizer;
+
+ // All in progress arrays and objects being parsed, in order from outermost
+ // to innermost.
+ Vector<typename HandlerT::StackEntry, 10> stack;
+
+ public:
+ JSONPerHandlerParser(ContextT* context, mozilla::Range<const CharT> data)
+ : handler(context), tokenizer(data, this), stack(context) {}
+
+ JSONPerHandlerParser(JSONPerHandlerParser&& other) noexcept
+ : handler(std::move(other.handler)),
+ tokenizer(std::move(other.tokenizer)),
+ stack(handler.context()) {
+ tokenizer.fixupParser(this);
+ }
+
+ ~JSONPerHandlerParser();
+
+ JSONPerHandlerParser(const JSONPerHandlerParser<CharT, HandlerT>& other) =
+ delete;
+ void operator=(const JSONPerHandlerParser<CharT, HandlerT>& other) = delete;
+
+ template <typename TempValueT, typename ResultSetter>
+ inline bool parseImpl(TempValueT& value, ResultSetter setResult);
+
+ void outOfMemory();
+
+ void error(const char* msg);
+};
+
+template <typename CharT>
+class MOZ_STACK_CLASS JSONParser
+ : JSONPerHandlerParser<CharT, JSONFullParseHandler<CharT>> {
+ using Base = JSONPerHandlerParser<CharT, JSONFullParseHandler<CharT>>;
+
+ public:
+ using ParseType = JSONFullParseHandlerAnyChar::ParseType;
+
+ /* Public API */
+
+ /* Create a parser for the provided JSON data. */
+ JSONParser(JSContext* cx, mozilla::Range<const CharT> data,
+ ParseType parseType)
+ : Base(cx, data) {
+ this->handler.parseType = parseType;
+ }
+
+ /* Allow move construction for use with Rooted. */
+ JSONParser(JSONParser&& other) noexcept : Base(std::move(other)) {}
+
+ JSONParser(const JSONParser& other) = delete;
+ void operator=(const JSONParser& other) = delete;
+
+ /*
+ * Parse the JSON data specified at construction time. If it parses
+ * successfully, store the prescribed value in *vp and return true. If an
+ * internal error (e.g. OOM) occurs during parsing, return false.
+ * Otherwise, if invalid input was specifed but no internal error occurred,
+ * behavior depends upon the error handling specified at construction: if
+ * error handling is RaiseError then throw a SyntaxError and return false,
+ * otherwise return true and set *vp to |undefined|. (JSON syntax can't
+ * represent |undefined|, so the JSON data couldn't have specified it.)
+ */
+ bool parse(JS::MutableHandle<JS::Value> vp);
+ bool parse(JS::MutableHandle<JS::Value> vp,
+ JS::MutableHandle<ParseRecordObject> pro);
+
+ void trace(JSTracer* trc);
+};
+
+template <typename CharT, typename Wrapper>
+class MutableWrappedPtrOperations<JSONParser<CharT>, Wrapper>
+ : public WrappedPtrOperations<JSONParser<CharT>, Wrapper> {
+ public:
+ bool parse(JS::MutableHandle<JS::Value> vp) {
+ return static_cast<Wrapper*>(this)->get().parse(vp);
+ }
+ bool parse(JS::MutableHandle<JS::Value> vp,
+ JS::MutableHandle<ParseRecordObject> pro) {
+ return static_cast<Wrapper*>(this)->get().parse(vp, pro);
+ }
+};
+
+template <typename CharT>
+class MOZ_STACK_CLASS JSONSyntaxParser
+ : JSONPerHandlerParser<CharT, JSONSyntaxParseHandler<CharT>> {
+ using HandlerT = JSONSyntaxParseHandler<CharT>;
+ using Base = JSONPerHandlerParser<CharT, HandlerT>;
+
+ public:
+ JSONSyntaxParser(FrontendContext* fc, mozilla::Range<const CharT> data)
+ : Base(fc, data) {}
+
+ JSONSyntaxParser(JSONSyntaxParser<CharT>&& other) noexcept
+ : Base(std::move(other)) {}
+
+ JSONSyntaxParser(const JSONSyntaxParser& other) = delete;
+ void operator=(const JSONSyntaxParser& other) = delete;
+
+ bool parse();
+};
+
+} /* namespace js */
+
+#endif /* vm_JSONParser_h */