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317 | // Copyright (C) 2017-2023 Internet Systems Consortium, Inc. ("ISC")
//
// 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 PARSER_CONTEXT_H
#define PARSER_CONTEXT_H
#include <string><--- Include file: not found. Please note: Cppcheck does not need standard library headers to get proper results.
#include <map><--- Include file:
#include <vector><--- Include file: not found. Please note: Cppcheck does not need standard library headers to get proper results.
#include <agent/agent_parser.h>
#include <agent/parser_context_decl.h>
#include <exceptions/exceptions.h>
// Tell Flex the lexer's prototype ...
#define YY_DECL isc::agent::AgentParser::symbol_type agent_lex (ParserContext& driver)
// ... and declare it for the parser's sake.
YY_DECL;
namespace isc {
namespace agent {
/// @brief Parser context is a wrapper around flex/bison instances dedicated to
/// Control-agent config file parser.
///
/// It follows the same principle as other components. The primary interface
/// are @ref parseString and @ref parseFile methods. All other methods are
/// public for testing purposes only. This interface allows parsing the
/// whole configuration with syntactic checking (which is by far the most
/// frequent use), but it also allows parsing input as generic JSON or
/// parse only content of the Control-agent object, which is a subset
/// of full grammar (this will be very useful for unit-tests to not duplicate
/// unnecessary parts of the config file).
class ParserContext
{
public:
/// @brief Defines currently supported scopes
///
/// AgentParser is able to parse several types of scope. Usually,
/// when it parses a config file, it expects the data to have a map
/// with Control-agent in it and all the parameters within that map.
/// However, sometimes the parser is expected to parse only a subset
/// of that information.
typedef enum {
/// This parser will parse the content as generic JSON.
PARSER_JSON,
/// This parser will expect the content as Control-agent config wrapped
/// in a map (that's the regular config file)
PARSER_AGENT,
/// This parser will expect only the content of Control-agent.
PARSER_SUB_AGENT
} ParserType;
/// @brief Default constructor.
ParserContext();
/// @brief destructor
virtual ~ParserContext();
/// @brief JSON elements being parsed.
std::vector<isc::data::ElementPtr> stack_;
/// @brief Method called before scanning starts on a string.
///
/// @param str string to be parsed
/// @param type specifies expected content
void scanStringBegin(const std::string& str, ParserType type);
/// @brief Method called before scanning starts on a file.
///
/// @param f stdio FILE pointer
/// @param filename file to be parsed
/// @param type specifies expected content
void scanFileBegin(FILE* f, const std::string& filename, ParserType type);
/// @brief Method called after the last tokens are scanned.
void scanEnd();
/// @brief Divert input to an include file.
///
/// @param filename file to be included
void includeFile(const std::string& filename);
/// @brief Run the parser on the string specified.
///
/// This method parses specified string. Depending on the value of
/// parser_type, parser may either check only that the input is valid
/// JSON, or may do more specific syntax checking. See @ref ParserType
/// for supported syntax checkers.
///
/// @param str string to be parsed
/// @param parser_type specifies expected content (usually AGENT or generic JSON)
/// @return Element structure representing parsed text.
isc::data::ElementPtr parseString(const std::string& str,
ParserType parser_type);
/// @brief Run the parser on the file specified.
///
/// This method parses specified file. Depending on the value of
/// parser_type, parser may either check only that the input is valid
/// JSON, or may do more specific syntax checking. See @ref ParserType
/// for supported syntax checkers.
///
/// @param filename file to be parsed
/// @param parser_type specifies expected content (usually PARSER_AGENT or
/// PARSER_JSON)
/// @return Element structure representing parsed text.
isc::data::ElementPtr parseFile(const std::string& filename,
ParserType parser_type);
/// @brief Error handler
///
/// @note The optional position for an error in a string begins by 1
/// so the caller should add 1 to the position of the C++ string.
///
/// @param loc location within the parsed file where the problem was experienced.
/// @param what string explaining the nature of the error.
/// @param pos optional position for in string errors.
/// @throw ParseError
void error(const isc::agent::location& loc,
const std::string& what,
size_t pos = 0);
/// @brief Error handler
///
/// This is a simplified error reporting tool for possible future
/// cases when the AgentParser is not able to handle the packet.
///
/// @param what string explaining the nature of the error.
/// @throw ParseError
void error(const std::string& what);
/// @brief Fatal error handler
///
/// This is for should not happen but fatal errors.
/// Used by YY_FATAL_ERROR macro so required to be static.
///
/// @param what string explaining the nature of the error.
/// @throw ParseError
static void fatal(const std::string& what);
/// @brief Converts bison's position to one understandable by isc::data::Element
///
/// Convert a bison location into an element position
/// (take the begin, the end is lost)
///
/// @param loc location in bison format
/// @return Position in format accepted by Element
isc::data::Element::Position loc2pos(isc::agent::location& loc);
/// @brief Check if a required parameter is present
///
/// Check if a required parameter is present in the map at the top
/// of the stack and raise an error when it is not.
///
/// @param name name of the parameter to check
/// @param open_loc location of the opening curly bracket
/// @param close_loc location of the closing curly bracket
/// @throw ParseError
void require(const std::string& name,
isc::data::Element::Position open_loc,
isc::data::Element::Position close_loc);
/// @brief Check if a parameter is already present
///
/// Check if a parameter is already present in the map at the top
/// of the stack and raise an error when it is.
///
/// @param name name of the parameter to check
/// @param loc location of the current parameter
/// @throw ParseError
void unique(const std::string& name,
isc::data::Element::Position loc);
/// @brief Warning handler
///
/// @param loc location within the parsed file where the problem was experienced
/// @param what string explaining the nature of the error
///
/// @throw ParseError
void warning(const isc::agent::location& loc, const std::string& what);
/// @brief Warning for extra commas
///
/// @param loc location within the parsed file of the extra comma
///
/// @throw ParseError
void warnAboutExtraCommas(const isc::agent::location& loc);
/// @brief Defines syntactic contexts for lexical tie-ins
typedef enum {
///< This one is used in pure JSON mode.
NO_KEYWORDS,
///< Used while parsing top level (that contains Control-agent)
CONFIG,
///< Used while parsing content of Agent.
AGENT,
///< Used while parsing Control-agent/Authentication.
AUTHENTICATION,
///< Used while parsing Control-agent/Authentication/type.
AUTH_TYPE,
///< Used while parsing Control-agent/Authentication/clients.
CLIENTS,
///< Used while parsing Control-agent/control-sockets.
CONTROL_SOCKETS,
///< Used while parsing Control-agent/control-socket/*-server.
SERVER,
///< Used while parsing Control-agent/control-socket/*-server/socket-type.
SOCKET_TYPE,
///< Used while parsing Control-agent/hooks-libraries.
HOOKS_LIBRARIES,
///< Used while parsing Control-agent/loggers structures.
LOGGERS,
///< Used while parsing Control-agent/loggers/output-options structures.
OUTPUT_OPTIONS
} LexerContext;
/// @brief File name
std::string file_;
/// @brief File name stack
std::vector<std::string> files_;
/// @brief Location of the current token
///
/// The lexer will keep updating it. This variable will be useful
/// for logging errors.
isc::agent::location loc_;
/// @brief Location stack
std::vector<isc::agent::location> locs_;
/// @brief Lexer state stack
std::vector<struct yy_buffer_state*> states_;
/// @brief sFile (aka FILE)
FILE* sfile_;
/// @brief sFile (aka FILE) stack
///
/// This is a stack of files. Typically there's only one file (the
/// one being currently parsed), but there may be more if one
/// file includes another.
std::vector<FILE*> sfiles_;
/// @brief Current syntactic context
LexerContext ctx_;
/// @brief Enter a new syntactic context
///
/// Entering a new syntactic context is useful in several ways.
/// First, it allows the parser to avoid conflicts. Second, it
/// allows the lexer to return different tokens depending on
/// context (e.g. if "renew-timer" string is detected, the lexer
/// will return STRING token if in JSON mode or RENEW_TIMER if
/// in DHCP6 mode. Finally, the syntactic context allows the
/// error message to be more descriptive if the input string
/// does not parse properly. Control Agent parser uses simplified
/// contexts: either it recognizes keywords (value set to KEYWORDS)
/// or not (value set to NO_KEYWORDS).
///
/// Make sure to call @ref leave() once the parsing of your
/// context is complete.
///
/// @param ctx the syntactic context to enter into
void enter(const LexerContext& ctx);
/// @brief Leave a syntactic context
///
/// @ref enter() must be called before (when entering a new scope
/// or context). Once you complete the parsing, this method
/// should be called.
///
/// @throw isc::Unexpected if unbalanced (more leave() than enter() calls)
void leave();
/// @brief Get the syntactic context name
///
/// @return printable name of the context.
const std::string contextName();
private:
/// @brief Flag determining scanner debugging.
bool trace_scanning_;
/// @brief Flag determining parser debugging.
bool trace_parsing_;
/// @brief Syntactic context stack
std::vector<LexerContext> cstack_;
/// @brief Common part of parseXXX
///
/// @return Element structure representing parsed text.
isc::data::ElementPtr parseCommon();
};
} // end of isc::eval namespace
} // end of isc namespace
#endif
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