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Diffstat (limited to 'utils/config/parser.cpp')
| -rw-r--r-- | utils/config/parser.cpp | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/utils/config/parser.cpp b/utils/config/parser.cpp new file mode 100644 index 000000000000..7bfe5517fdd0 --- /dev/null +++ b/utils/config/parser.cpp @@ -0,0 +1,181 @@ +// Copyright 2012 The Kyua Authors. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// * Neither the name of Google Inc. nor the names of its contributors +// may be used to endorse or promote products derived from this software +// without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include "utils/config/parser.hpp" + +#include <lutok/exceptions.hpp> +#include <lutok/operations.hpp> +#include <lutok/stack_cleaner.hpp> +#include <lutok/state.ipp> + +#include "utils/config/exceptions.hpp" +#include "utils/config/lua_module.hpp" +#include "utils/config/tree.ipp" +#include "utils/fs/path.hpp" +#include "utils/logging/macros.hpp" +#include "utils/noncopyable.hpp" + +namespace config = utils::config; + + +// History of configuration file versions: +// +// 2 - Changed the syntax() call to take only a version number, instead of the +// word 'config' as the first argument and the version as the second one. +// Files now start with syntax(2) instead of syntax('config', 1). +// +// 1 - Initial version. + + +/// Internal implementation of the parser. +struct utils::config::parser::impl : utils::noncopyable { + /// Pointer to the parent parser. Needed for callbacks. + parser* _parent; + + /// The Lua state used by this parser to process the configuration file. + lutok::state _state; + + /// The tree to be filed in by the configuration parameters, as provided by + /// the caller. + config::tree& _tree; + + /// Whether syntax() has been called or not. + bool _syntax_called; + + /// Constructs a new implementation. + /// + /// \param parent_ Pointer to the class being constructed. + /// \param config_tree_ The configuration tree provided by the user. + impl(parser* const parent_, tree& config_tree_) : + _parent(parent_), _tree(config_tree_), _syntax_called(false) + { + } + + friend void lua_syntax(lutok::state&); + + /// Callback executed by the Lua syntax() function. + /// + /// \param syntax_version The syntax format version as provided by the + /// configuration file in the call to syntax(). + void + syntax_callback(const int syntax_version) + { + if (_syntax_called) + throw syntax_error("syntax() can only be called once"); + _syntax_called = true; + + // Allow the parser caller to populate the tree with its own schema + // depending on the format/version combination. + _parent->setup(_tree, syntax_version); + + // Export the config module to the Lua state so that all global variable + // accesses are redirected to the configuration tree. + config::redirect(_state, _tree); + } +}; + + +namespace { + + +static int +lua_syntax(lutok::state& state) +{ + if (!state.is_number(-1)) + throw config::value_error("Last argument to syntax must be a number"); + const int syntax_version = state.to_integer(-1); + + if (syntax_version == 1) { + if (state.get_top() != 2) + throw config::value_error("Version 1 files need two arguments to " + "syntax()"); + if (!state.is_string(-2) || state.to_string(-2) != "config") + throw config::value_error("First argument to syntax must be " + "'config' for version 1 files"); + } else { + if (state.get_top() != 1) + throw config::value_error("syntax() only takes one argument"); + } + + state.get_global("_config_parser"); + config::parser::impl* impl = + *state.to_userdata< config::parser::impl* >(-1); + state.pop(1); + + impl->syntax_callback(syntax_version); + + return 0; +} + + +} // anonymous namespace + + +/// Constructs a new parser. +/// +/// \param [in,out] config_tree The configuration tree into which the values set +/// in the configuration file will be stored. +config::parser::parser(tree& config_tree) : + _pimpl(new impl(this, config_tree)) +{ + lutok::stack_cleaner cleaner(_pimpl->_state); + + _pimpl->_state.push_cxx_function(lua_syntax); + _pimpl->_state.set_global("syntax"); + *_pimpl->_state.new_userdata< config::parser::impl* >() = _pimpl.get(); + _pimpl->_state.set_global("_config_parser"); +} + + +/// Destructor. +config::parser::~parser(void) +{ +} + + +/// Parses a configuration file. +/// +/// \post The tree registered during the construction of this class is updated +/// to contain the values read from the configuration file. If the processing +/// fails, the state of the output tree is undefined. +/// +/// \param file The path to the file to process. +/// +/// \throw syntax_error If there is any problem processing the file. +void +config::parser::parse(const fs::path& file) +{ + try { + lutok::do_file(_pimpl->_state, file.str(), 0, 0, 0); + } catch (const lutok::error& e) { + throw syntax_error(e.what()); + } + + if (!_pimpl->_syntax_called) + throw syntax_error("No syntax defined (no call to syntax() found)"); +} |