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+// 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)");
+}