libcamera/vivid.git - libcamera pipeline handler for VIVID

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author	Laurent Pinchart <laurent.pinchart@ideasonboard.com>	2022-09-28 15:00:02 +0300
committer	Laurent Pinchart <laurent.pinchart@ideasonboard.com>	2022-09-30 21:51:14 +0300
commit	b4e31a88d304e09e200af9d1e00760074cc854c2 (patch)
tree	c3f06803b88ba5f20959933d226c2313d7674bf0 /src/ipa/libipa/algorithm.cpp
parent	930b4927acac9bee2a45da574c7e98e17be825a8 (diff)

Documentation: theme: Specify license of search.png

The search.png icon is derived from the magnifying glass icon used by most websites, which comes from Font Awesome. Specify its license and attribution in dep5, as PNG files can't contain SPDX headers. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

Diffstat (limited to 'src/ipa/libipa/algorithm.cpp')

0 files changed, 0 insertions, 0 deletions

/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright (C) 2019, Google Inc. * * options.cpp - cam - Options parsing */ #include <assert.h> #include <getopt.h> #include <iomanip> #include <iostream> #include <string.h> #include "options.h" /** * \enum OptionArgument * \brief Indicate if an option takes an argument * * \var OptionArgument::ArgumentNone * \brief The option doesn't accept any argument * * \var OptionArgument::ArgumentRequired * \brief The option requires an argument * * \var OptionArgument::ArgumentOptional * \brief The option accepts an optional argument */ /** * \enum OptionType * \brief The type of argument for an option * * \var OptionType::OptionNone * \brief No argument type, used for options that take no argument * * \var OptionType::OptionInteger * \brief Integer argument type, with an optional base prefix (`0` for base 8, * `0x` for base 16, none for base 10) * * \var OptionType::OptionString * \brief String argument * * \var OptionType::OptionKeyValue * \brief key=value list argument */ /* ----------------------------------------------------------------------------- * Option */ /** * \struct Option * \brief Store metadata about an option * * \var Option::opt * \brief The option identifier * * \var Option::type * \brief The type of the option argument * * \var Option::name * \brief The option name * * \var Option::argument * \brief Whether the option accepts an optional argument, a mandatory * argument, or no argument at all * * \var Option::argumentName * \brief The argument name used in the help text * * \var Option::help * \brief The help text (may be a multi-line string) * * \var Option::keyValueParser * \brief For options of type OptionType::OptionKeyValue, the key-value parser * to parse the argument * * \var Option::isArray * \brief Whether the option can appear once or multiple times * * \var Option::parent * \brief The parent option * * \var Option::children * \brief List of child options, storing all options whose parent is this option * * \fn Option::hasShortOption() * \brief Tell if the option has a short option specifier (e.g. `-f`) * \return True if the option has a short option specifier, false otherwise * * \fn Option::hasLongOption() * \brief Tell if the option has a long option specifier (e.g. `--foo`) * \return True if the option has a long option specifier, false otherwise */ struct Option { int opt; OptionType type; const char *name; OptionArgument argument; const char *argumentName; const char *help; KeyValueParser *keyValueParser; bool isArray; Option *parent; std::list<Option> children; bool hasShortOption() const { return isalnum(opt); } bool hasLongOption() const { return name != nullptr; } const char *typeName() const; std::string optionName() const; }; /** * \brief Retrieve a string describing the option type * \return A string describing the option type */ const char *Option::typeName() const { switch (type) { case OptionNone: return "none"; case OptionInteger: return "integer"; case OptionString: return "string"; case OptionKeyValue: return "key=value"; } return "unknown"; } /** * \brief Retrieve a string describing the option name, with leading dashes * \return A string describing the option name, as a long option identifier * (double dash) if the option has a name, or a short option identifier (single * dash) otherwise */ std::string Option::optionName() const { if (name) return "--" + std::string(name); else return "-" + std::string(1, opt); } /* ----------------------------------------------------------------------------- * OptionBase<T> */ /** * \class template<typename T> OptionBase * \brief Container to store the values of parsed options * \tparam T The type through which options are identified * * The OptionsBase class is generated by a parser (either OptionsParser or * KeyValueParser) when parsing options. It stores values for all the options * found, and exposes accessor functions to retrieve them. The options are * accessed through an identifier to type \a T, which is an int referencing an * Option::opt for OptionsParser, or a std::string referencing an Option::name * for KeyValueParser. */ /** * \fn OptionsBase::OptionsBase() * \brief Construct an OptionsBase instance * * The constructed instance is initially invalid, and will be populated by the * options parser. */ /** * \brief Tell if the stored options list is empty * \return True if the container is empty, false otherwise */ template<typename T> bool OptionsBase<T>::empty() const { return values_.empty(); } /** * \brief Tell if the options parsing completed successfully * \return True if the container is returned after successfully parsing * options, false if it is returned after an error was detected during parsing */ template<typename T> bool OptionsBase<T>::valid() const { return valid_; } /** * \brief Tell if the option \a opt is specified * \param[in] opt The option to search for * \return True if the \a opt option is set, false otherwise */ template<typename T> bool OptionsBase<T>::isSet(const T &opt) const { return values_.find(opt) != values_.end(); } /** * \brief Retrieve the value of option \a opt * \param[in] opt The option to retrieve * \return The value of option \a opt if found, an empty OptionValue otherwise */ template<typename T> const OptionValue &OptionsBase<T>::operator[](const T &opt) const { static const OptionValue empty; auto it = values_.find(opt); if (it != values_.end()) return it->second; return empty; } /** * \brief Mark the container as invalid * * This function can be used in a key-value parser's override of the * KeyValueParser::parse() function to mark the returned options as invalid if * a validation error occurs. */ template<typename T> void OptionsBase<T>::invalidate() { valid_ = false; } template<typename T> bool OptionsBase<T>::parseValue(const T &opt, const Option &option, const char *arg) { OptionValue value; switch (option.type) { case OptionNone: break; case OptionInteger: unsigned int integer; if (arg) { char *endptr; integer = strtoul(arg, &endptr, 0); if (*endptr != '\0') return false; } else { integer = 0; } value = OptionValue(integer); break; case OptionString: value = OptionValue(arg ? arg : ""); break; case OptionKeyValue: KeyValueParser *kvParser = option.keyValueParser; KeyValueParser::Options keyValues = kvParser->parse(arg); if (!keyValues.valid()) return false; value = OptionValue(keyValues); break; } if (option.isArray) values_[opt].addValue(value); else values_[opt] = value; return true; } template class OptionsBase<int>; template class OptionsBase<std::string>; /* ----------------------------------------------------------------------------- * KeyValueParser */ /** * \class KeyValueParser * \brief A specialized parser for list of key-value pairs * * The KeyValueParser is an options parser for comma-separated lists of * `key=value` pairs. The supported keys are added to the parser with * addOption(). A given key can only appear once in the parsed list. * * Instances of this class can be passed to the OptionsParser::addOption() * function to create options that take key-value pairs as an option argument. * Specialized versions of the key-value parser can be created by inheriting * from this class, to pre-build the options list in the constructor, and to add * custom validation by overriding the parse() function. */ /** * \class KeyValueParser::Options * \brief An option list generated by the key-value parser * * This is a specialization of OptionsBase with the option reference type set to * std::string. */ KeyValueParser::KeyValueParser() = default; KeyValueParser::~KeyValueParser() = default; /** * \brief Add a supported option to the parser * \param[in] name The option name, corresponding to the key name in the * key=value pair. The name shall be unique. * \param[in] type The type of the value in the key=value pair * \param[in] help The help text * \param[in] argument Whether the value is optional, mandatory or not allowed. * Shall be ArgumentNone if \a type is OptionNone. * * \sa OptionsParser * * \return True if the option was added successfully, false if an error * occurred. */ bool KeyValueParser::addOption(const char *name, OptionType type, const char *help, OptionArgument argument) { if (!name) return false; if (!help || help[0] == '\0') return false; if (argument != ArgumentNone && type == OptionNone) return false; /* Reject duplicate options. */ if (optionsMap_.find(name) != optionsMap_.end()) return false; optionsMap_[name] = Option({ 0, type, name, argument, nullptr, help, nullptr, false, nullptr, {} }); return true; } /** * \brief Parse a string containing a list of key-value pairs * \param[in] arguments The key-value pairs string to parse * * If a parsing error occurs, the parsing stops and the function returns an * invalid container. The container is populated with the options successfully * parsed so far. * * \return A valid container with the list of parsed options on success, or an * invalid container otherwise */ KeyValueParser::Options KeyValueParser::parse(const char *arguments) { Options options; for (const char *pair = arguments; *arguments != '\0'; pair = arguments) { const char *comma = strchrnul(arguments, ','); size_t len = comma - pair; /* Skip over the comma. */ arguments = *comma == ',' ? comma + 1 : comma; /* Skip to the next pair if the pair is empty. */ if (!len) continue; std::string key; std::string value; const char *separator = static_cast<const char *>(memchr(pair, '=', len)); if (!separator) { key = std::string(pair, len); value = ""; } else { key = std::string(pair, separator - pair); value = std::string(separator + 1, comma - separator - 1); } /* The key is mandatory, the value might be optional. */ if (key.empty()) continue; if (optionsMap_.find(key) == optionsMap_.end()) { std::cerr << "Invalid option " << key << std::endl; return options; } OptionArgument arg = optionsMap_[key].argument; if (value.empty() && arg == ArgumentRequired) { std::cerr << "Option " << key << " requires an argument" << std::endl; return options; } else if (!value.empty() && arg == ArgumentNone) { std::cerr << "Option " << key << " takes no argument" << std::endl; return options; } const Option &option = optionsMap_[key]; if (!options.parseValue(key, option, value.c_str())) { std::cerr << "Failed to parse '" << value << "' as " << option.typeName() << " for option " << key << std::endl; return options; } } options.valid_ = true; return options; } unsigned int KeyValueParser::maxOptionLength() const { unsigned int maxLength = 0; for (auto const &iter : optionsMap_) { const Option &option = iter.second; unsigned int length = 10 + strlen(option.name); if (option.argument != ArgumentNone) length += 1 + strlen(option.typeName()); if (option.argument == ArgumentOptional) length += 2; if (length > maxLength) maxLength = length; } return maxLength; } void KeyValueParser::usage(int indent) { for (auto const &iter : optionsMap_) { const Option &option = iter.second; std::string argument = std::string(" ") + option.name; if (option.argument != ArgumentNone) { if (option.argument == ArgumentOptional) argument += "[="; else argument += "="; argument += option.typeName(); if (option.argument == ArgumentOptional) argument += "]"; } std::cerr << std::setw(indent) << argument; for (const char *help = option.help, *end = help; end;) { end = strchr(help, '\n'); if (end) { std::cerr << std::string(help, end - help + 1); std::cerr << std::setw(indent) << " "; help = end + 1; } else { std::cerr << help << std::endl; } } } } /* ----------------------------------------------------------------------------- * OptionValue */ /** * \class OptionValue * \brief Container to store the value of an option * * The OptionValue class is a variant-type container to store the value of an * option. It supports empty values, integers, strings, key-value lists, as well * as arrays of those types. For array values, all array elements shall have the * same type. * * OptionValue instances are organized in a tree-based structure that matches * the parent-child relationship of the options added to the parser. Children * are retrieved with the children() function, and are stored as an * OptionsBase<int>. */ /** * \enum OptionValue::ValueType * \brief The option value type * * \var OptionValue::ValueType::ValueNone * \brief Empty value * * \var OptionValue::ValueType::ValueInteger * \brief Integer value (int) * * \var OptionValue::ValueType::ValueString * \brief String value (std::string) * * \var OptionValue::ValueType::ValueKeyValue * \brief Key-value list value (KeyValueParser::Options) * * \var OptionValue::ValueType::ValueArray * \brief Array value */ /** * \brief Construct an empty OptionValue instance * * The value type is set to ValueType::ValueNone. */ OptionValue::OptionValue() : type_(ValueNone), integer_(0) { } /** * \brief Construct an integer OptionValue instance * \param[in] value The integer value * * The value type is set to ValueType::ValueInteger. */ OptionValue::OptionValue(int value) : type_(ValueInteger), integer_(value) { } /** * \brief Construct a string OptionValue instance * \param[in] value The string value * * The value type is set to ValueType::ValueString. */ OptionValue::OptionValue(const char *value) : type_(ValueString), integer_(0), string_(value) { } /** * \brief Construct a string OptionValue instance * \param[in] value The string value * * The value type is set to ValueType::ValueString. */ OptionValue::OptionValue(const std::string &value) : type_(ValueString), integer_(0), string_(value) { } /** * \brief Construct a key-value OptionValue instance * \param[in] value The key-value list * * The value type is set to ValueType::ValueKeyValue. */ OptionValue::OptionValue(const KeyValueParser::Options &value) : type_(ValueKeyValue), integer_(0), keyValues_(value) { } /** * \brief Add an entry to an array value * \param[in] value The entry value * * This function can only be called if the OptionValue type is * ValueType::ValueNone or ValueType::ValueArray. Upon return, the type will be * set to ValueType::ValueArray. */ void OptionValue::addValue(const OptionValue &value) { assert(type_ == ValueNone || type_ == ValueArray); type_ = ValueArray; array_.push_back(value); } /** * \fn OptionValue::type() * \brief Retrieve the value type * \return The value type */ /** * \fn OptionValue::empty() * \brief Check if the value is empty * \return True if the value is empty (type set to ValueType::ValueNone), or * false otherwise */ /** * \brief Cast the value to an int * \return The option value as an int, or 0 if the value type isn't * ValueType::ValueInteger */ OptionValue::operator int() const { return toInteger(); } /** * \brief Cast the value to a std::string * \return The option value as an std::string, or an empty string if the value * type isn't ValueType::ValueString */ OptionValue::operator std::string() const { return toString(); } /** * \brief Retrieve the value as an int * \return The option value as an int, or 0 if the value type isn't * ValueType::ValueInteger */ int OptionValue::toInteger() const { if (type_ != ValueInteger) return 0; return integer_; } /** * \brief Retrieve the value as a std::string * \return The option value as a std::string, or an empty string if the value * type isn't ValueType::ValueString */ std::string OptionValue::toString() const { if (type_ != ValueString) return std::string(); return string_; } /** * \brief Retrieve the value as a key-value list * * The behaviour is undefined if the value type isn't ValueType::ValueKeyValue. * * \return The option value as a KeyValueParser::Options */ const KeyValueParser::Options &OptionValue::toKeyValues() const { assert(type_ == ValueKeyValue); return keyValues_; } /** * \brief Retrieve the value as an array * * The behaviour is undefined if the value type isn't ValueType::ValueArray. * * \return The option value as a std::vector of OptionValue */ const std::vector<OptionValue> &OptionValue::toArray() const { assert(type_ == ValueArray); return array_; } /** * \brief Retrieve the list of child values * \return The list of child values */ const OptionsParser::Options &OptionValue::children() const { return children_; } /* ----------------------------------------------------------------------------- * OptionsParser */ /** * \class OptionsParser * \brief A command line options parser * * The OptionsParser class is an easy to use options parser for POSIX-style * command line options. Supports short (e.g. `-f`) and long (e.g. `--foo`) * options, optional and mandatory arguments, automatic parsing arguments for * integer types and comma-separated list of key=value pairs, and multi-value * arguments. It handles help text generation automatically. * * An OptionsParser instance is initialized by adding supported options with * addOption(). Options are specified by an identifier and a name. If the * identifier is an alphanumeric character, it will be used by the parser as a * short option identifier (e.g. `-f`). The name, if specified, will be used as * a long option identifier (e.g. `--foo`). It should not include the double * dashes. The name is optional if the option identifier is an alphanumeric * character and mandatory otherwise. * * An option has a mandatory help text, which is used to print the full options * list with the usage() function. The help text may be a multi-line string. * Correct indentation of the help text is handled automatically. * * Options accept arguments when created with OptionArgument::ArgumentRequired * or OptionArgument::ArgumentOptional. If the argument is required, it can be * specified as a positional argument after the option (e.g. `-f bar`, * `--foo bar`), collated with the short option (e.g. `-fbar`) or separated from * the long option by an equal sign (e.g. `--foo=bar`'). When the argument is * optional, it must be collated with the short option or separated from the * long option by an equal sign. * * If an option has a required or optional argument, an argument name must be * set when adding the option. The argument name is used in the help text as a * place holder for an argument value. For instance, a `--write` option that * takes a file name as an argument could set the argument name to `filename`, * and the help text would display `--write filename`. This is only used to * clarify the help text and has no effect on option parsing. * * The option type tells the parser how to process the argument. Arguments for * string options (OptionType::OptionString) are stored as-is without any * processing. Arguments for integer options (OptionType::OptionInteger) are * converted to an integer value, using an optional base prefix (`0` for base 8, * `0x` for base 16, none for base 10). Arguments for key-value options are * parsed by a KeyValueParser given to addOption(). * * By default, a given option can appear once only in the parsed command line. * If the option is created as an array option, the parser will accept multiple * instances of the option. The order in which identical options are specified * is preserved in the values of an array option. * * After preparing the parser, it can be used any number of times to parse * command line options with the parse() function. The function returns an * Options instance that stores the values for the parsed options. The * Options::isSet() function can be used to test if an option has been found, * and is the only way to access options that take no argument (specified by * OptionType::OptionNone and OptionArgument::ArgumentNone). For options that * accept an argument, the option value can be access by Options::operator[]() * using the option identifier as the key. The order in which different options * are specified on the command line isn't preserved. * * Options can be created with parent-child relationships to organize them as a * tree instead of a flat list. When parsing a command line, the child options * are considered related to the parent option that precedes them. This is * useful when the parent is an array option. The Options values list generated * by the parser then turns into a tree, which each parent value storing the * values of child options that follow that instance of the parent option. * For instance, with a `capture` option specified as a child of a `camera` * array option, parsing the command line * * `--camera 1 --capture=10 --camera 2 --capture=20` * * will return an Options instance containing a single OptionValue instance of * array type, for the `camera` option. The OptionValue will contain two * entries, with the first entry containing the integer value 1 and the second * entry the integer value 2. Each of those entries will in turn store an * Options instance that contains the respective children. The first entry will * store in its children a `capture` option of value 10, and the second entry a * `capture` option of value 20. * * The command line * * `--capture=10 --camera 1` * * would result in a parsing error, as the `capture` option has no preceding * `camera` option on the command line. */ /** * \class OptionsParser::Options * \brief An option list generated by the options parser * * This is a specialization of OptionsBase with the option reference type set to * int. */ OptionsParser::OptionsParser() = default; OptionsParser::~OptionsParser() = default; /** * \brief Add an option to the parser * \param[in] opt The option identifier * \param[in] type The type of the option argument * \param[in] help The help text (may be a multi-line string) * \param[in] name The option name * \param[in] argument Whether the option accepts an optional argument, a * mandatory argument, or no argument at all * \param[in] argumentName The argument name used in the help text * \param[in] array Whether the option can appear once or multiple times * \param[in] parent The identifier of the parent option (optional) * * \return True if the option was added successfully, false if an error * occurred. */ bool OptionsParser::addOption(int opt, OptionType type, const char *help, const char *name, OptionArgument argument, const char *argumentName, bool array, int parent) { /* * Options must have at least a short or long name, and a text message. * If an argument is accepted, it must be described by argumentName. */ if (!isalnum(opt) && !name) return false; if (!help || help[0] == '\0') return false; if (argument != ArgumentNone && !argumentName) return false; /* Reject duplicate options. */ if (optionsMap_.find(opt) != optionsMap_.end()) return false; /* * If a parent is specified, create the option as a child of its parent. * Otherwise, create it in the parser's options list. */ Option *option; if (parent) { auto iter = optionsMap_.find(parent); if (iter == optionsMap_.end()) return false; Option *parentOpt = iter->second; parentOpt->children.push_back({ opt, type, name, argument, argumentName, help, nullptr, array, parentOpt, {} }); option = &parentOpt->children.back(); } else { options_.push_back({ opt, type, name, argument, argumentName, help, nullptr, array, nullptr, {} }); option = &options_.back(); } optionsMap_[opt] = option; return true; } /** * \brief Add a key-value pair option to the parser * \param[in] opt The option identifier * \param[in] parser The KeyValueParser for the option value * \param[in] help The help text (may be a multi-line string) * \param[in] name The option name * \param[in] array Whether the option can appear once or multiple times * * \sa Option * * \return True if the option was added successfully, false if an error * occurred. */ bool OptionsParser::addOption(int opt, KeyValueParser *parser, const char *help, const char *name, bool array, int parent) { if (!addOption(opt, OptionKeyValue, help, name, ArgumentRequired, "key=value[,key=value,...]", array, parent)) return false; optionsMap_[opt]->keyValueParser = parser; return true; } /** * \brief Parse command line arguments * \param[in] argc The number of arguments in the \a argv array * \param[in] argv The array of arguments * * If a parsing error occurs, the parsing stops, the function prints an error * message that identifies the invalid argument, prints usage information with * usage(), and returns an invalid container. The container is populated with * the options successfully parsed so far. * * \return A valid container with the list of parsed options on success, or an * invalid container otherwise */ OptionsParser::Options OptionsParser::parse(int argc, char **argv) { OptionsParser::Options options; /* * Allocate short and long options arrays large enough to contain all * options. */ char shortOptions[optionsMap_.size() * 3 + 2]; struct option longOptions[optionsMap_.size() + 1]; unsigned int ids = 0; unsigned int idl = 0; shortOptions[ids++] = ':'; for (const auto [opt, option] : optionsMap_) { if (option->hasShortOption()) { shortOptions[ids++] = opt; if (option->argument != ArgumentNone) shortOptions[ids++] = ':'; if (option->argument == ArgumentOptional) shortOptions[ids++] = ':'; } if (option->hasLongOption()) { longOptions[idl].name = option->name; switch (option->argument) { case ArgumentNone: longOptions[idl].has_arg = no_argument; break; case ArgumentRequired: longOptions[idl].has_arg = required_argument; break; case ArgumentOptional: longOptions[idl].has_arg = optional_argument; break; } longOptions[idl].flag = 0; longOptions[idl].val = option->opt; idl++; } } shortOptions[ids] = '\0'; memset(&longOptions[idl], 0, sizeof(longOptions[idl])); opterr = 0; while (true) { int c = getopt_long(argc, argv, shortOptions, longOptions, nullptr); if (c == -1) break; if (c == '?' || c == ':') { if (c == '?') std::cerr << "Invalid option "; else std::cerr << "Missing argument for option "; std::cerr << argv[optind - 1] << std::endl; usage(); return options; } const Option &option = *optionsMap_[c]; if (!parseValue(option, optarg, &options)) { usage(); return options; } } if (optind < argc) { std::cerr << "Invalid non-option argument '" << argv[optind] << "'" << std::endl; usage(); return options; } options.valid_ = true; return options; } /** * \brief Print usage text to std::cerr * * The usage text list all the supported option with their arguments. It is * generated automatically from the options added to the parser. Caller of this * function may print additional usage information for the application before * the list of options. */ void OptionsParser::usage() { unsigned int indent = 0; for (const auto &opt : optionsMap_) { const Option *option = opt.second; unsigned int length = 14; if (option->hasLongOption()) length += 2 + strlen(option->name); if (option->argument != ArgumentNone) length += 1 + strlen(option->argumentName); if (option->argument == ArgumentOptional) length += 2; if (option->isArray) length += 4; if (length > indent) indent = length; if (option->keyValueParser) { length = option->keyValueParser->maxOptionLength(); if (length > indent) indent = length; } } indent = (indent + 7) / 8 * 8; std::cerr << "Options:" << std::endl; std::ios_base::fmtflags f(std::cerr.flags()); std::cerr << std::left; usageOptions(options_, indent); std::cerr.flags(f); } void OptionsParser::usageOptions(const std::list<Option> &options, unsigned int indent) { std::vector<const Option *> parentOptions; for (const Option &option : options) { std::string argument; if (option.hasShortOption()) argument = std::string(" -") + static_cast<char>(option.opt); else argument = " "; if (option.hasLongOption()) { if (option.hasShortOption()) argument += ", "; else argument += " "; argument += std::string("--") + option.name; } if (option.argument != ArgumentNone) { if (option.argument == ArgumentOptional) argument += "[="; else argument += " "; argument += option.argumentName; if (option.argument == ArgumentOptional) argument += "]"; } if (option.isArray) argument += " ..."; std::cerr << std::setw(indent) << argument; for (const char *help = option.help, *end = help; end; ) { end = strchr(help, '\n'); if (end) { std::cerr << std::string(help, end - help + 1); std::cerr << std::setw(indent) << " "; help = end + 1; } else { std::cerr << help << std::endl; } } if (option.keyValueParser) option.keyValueParser->usage(indent); if (!option.children.empty()) parentOptions.push_back(&option); } if (parentOptions.empty()) return; for (const Option *option : parentOptions) { std::cerr << std::endl << "Options valid in the context of " << option->optionName() << ":" << std::endl; usageOptions(option->children, indent); } } std::tuple<OptionsParser::Options *, const Option *> OptionsParser::childOption(const Option *parent, Options *options) { /* * The parent argument points to the parent of the leaf node Option, * and the options argument to the root node of the Options tree. Use * recursive calls to traverse the Option tree up to the root node while * traversing the Options tree down to the leaf node: */ /* * - If we have no parent, we've reached the root node of the Option * tree, the options argument is what we need. */ if (!parent) return { options, nullptr }; /* * - If the parent has a parent, use recursion to move one level up the * Option tree. This returns the Options corresponding to parent, or * nullptr if a suitable Options child isn't found. */ if (parent->parent) { const Option *error; std::tie(options, error) = childOption(parent->parent, options); /* Propagate the error all the way back up the call stack. */ if (!error) return { options, error }; } /* * - The parent has no parent, we're now one level down the root. * Return the Options child corresponding to the parent. The child may * not exist if options are specified in an incorrect order. */ if (!options->isSet(parent->opt)) return { nullptr, parent }; /* * If the child value is of array type, children are not stored in the


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