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+/* 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
+ * value .children() list, but in the .children() of the value's array
+ * elements. Use the last array element in that case, as a child option
+ * relates to the last instance of its parent option.
+ */
+ const OptionValue *value = &(*options)[parent->opt];
+ if (value->type() == OptionValue::ValueArray)
+ value = &value->toArray().back();
+
+ return { const_cast<Options *>(&value->children()), nullptr };
+}
+
+bool OptionsParser::parseValue(const Option &option, const char *arg,
+ Options *options)
+{
+ const Option *error;
+
+ std::tie(options, error) = childOption(option.parent, options);
+ if (error) {
+ std::cerr << "Option " << option.optionName() << " requires a "
+ << error->optionName() << " context" << std::endl;
+ return false;
+ }
+
+ if (!options->parseValue(option.opt, option, arg)) {
+ std::cerr << "Can't parse " << option.typeName()
+ << " argument for option " << option.optionName()
+ << std::endl;
+ return false;
+ }
+
+ return true;
+}
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-06 11:41:24 +0000