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cpp_chlit_grammar.hpp @ 857

Revision 857, 13.3 KB checked in by igarcia, 19 years ago (diff)

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1	/*=============================================================================
2	Boost.Wave: A Standard compliant C++ preprocessor library
3
4	http://www.boost.org/
5
6	Copyright (c) 2001-2005 Hartmut Kaiser. Distributed under the Boost
7	Software License, Version 1.0. (See accompanying file
8	LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9	=============================================================================*/
10
11	#if !defined(CPP_CHLIT_GRAMMAR_HPP_9527D349_6592_449A_A409_42A001E6C64C_INCLUDED)
12	#define CPP_CHLIT_GRAMMAR_HPP_9527D349_6592_449A_A409_42A001E6C64C_INCLUDED
13
14	#include <limits> // sid::numeric_limits
15
16	#include <boost/static_assert.hpp>
17	#include <boost/cstdint.hpp>
18
19	#include <boost/spirit/core.hpp>
20	#include <boost/spirit/attribute/closure.hpp>
21	#include <boost/spirit/dynamic/if.hpp>
22
23	#include <boost/spirit/phoenix/operators.hpp>
24	#include <boost/spirit/phoenix/primitives.hpp>
25	#include <boost/spirit/phoenix/statements.hpp>
26	#include <boost/spirit/phoenix/functions.hpp>
27
28	#include <boost/wave/wave_config.hpp>
29	#include <boost/wave/cpp_exceptions.hpp>
30	#include <boost/wave/grammars/cpp_literal_grammar_gen.hpp>
31
32	///////////////////////////////////////////////////////////////////////////////
33	//
34	// Reusable grammar to parse a C++ style character literal
35	//
36	///////////////////////////////////////////////////////////////////////////////
37	namespace boost {
38	namespace wave {
39	namespace grammars {
40
41	namespace closures {
42
43	struct chlit_closure
44	: boost::spirit::closure<chlit_closure, boost::uint32_t, bool>
45	{
46	member1 value;
47	member2 long_lit;
48	};
49	}
50
51	namespace impl {
52
53	///////////////////////////////////////////////////////////////////////////////
54	//
55	// compose a multibyte character literal
56	//
57	///////////////////////////////////////////////////////////////////////////////
58	struct compose_character_literal {
59
60	template <typename ResultT, typename A1, typename A2, typename A3>
61	struct result {
62
63	typedef void type;
64	};
65
66	void
67	operator()(boost::uint32_t& value, bool long_lit, bool& overflow,
68	boost::uint32_t character) const
69	{
70	// The following assumes that wchar_t is max. 32 Bit
71	BOOST_STATIC_ASSERT(sizeof(wchar_t) <= 4);
72
73	static boost::uint32_t masks[] = {
74	0x000000ff, 0x0000ffff, 0x00ffffff, 0xffffffff
75	};
76	static boost::uint32_t overflow_masks[] = {
77	0xff000000, 0xffff0000, 0xffffff00, 0xffffffff
78	};
79
80	if (long_lit) {
81	// make sure no overflow will occur below
82	if ((value & overflow_masks[sizeof(wchar_t)-1]) != 0) {
83	overflow \|= true;
84	}
85	else {
86	// calculate the new value (avoiding a warning regarding
87	// shifting count >= size of the type)
88	value <<= 8 * (sizeof(wchar_t)-1);
89	value <<= 8;
90	value \|= character & masks[sizeof(wchar_t)-1];
91	}
92	}
93	else {
94	// make sure no overflow will occur below
95	if ((value & overflow_masks[sizeof(char)-1]) != 0) {
96	overflow \|= true;
97	}
98	else {
99	// calculate the new value
100	value <<= 8 * sizeof(char);
101	value \|= character & masks[sizeof(char)-1];
102	}
103	}
104	}
105	};
106	phoenix::function<compose_character_literal> const compose;
107
108	} // namespace impl
109
110	///////////////////////////////////////////////////////////////////////////////
111	// define, whether the rule's should generate some debug output
112	#define TRACE_CHLIT_GRAMMAR \
113	bool(BOOST_SPIRIT_DEBUG_FLAGS_CPP & BOOST_SPIRIT_DEBUG_FLAGS_CHLIT_GRAMMAR) \
114	/**/
115
116	struct chlit_grammar :
117	public boost::spirit::grammar<chlit_grammar,
118	closures::chlit_closure::context_t>
119	{
120	chlit_grammar()
121	: overflow(false)
122	{
123	BOOST_SPIRIT_DEBUG_TRACE_GRAMMAR_NAME(*this, "chlit_grammar",
124	TRACE_CHLIT_GRAMMAR);
125	}
126
127	template <typename ScannerT>
128	struct definition
129	{
130	typedef
131	boost::spirit::rule<ScannerT, closures::chlit_closure::context_t>
132	rule_t;
133
134	rule_t ch_lit;
135
136	definition(chlit_grammar const &self)
137	{
138	using namespace boost::spirit;
139	using namespace phoenix;
140
141	// special parsers for '\x..' and L'\x....'
142	typedef uint_parser<
143	unsigned int, 16, 1, 2 * sizeof(char)
144	> hex_char_parser_type;
145	typedef uint_parser<
146	unsigned int, 16, 1, 2 * sizeof(wchar_t)
147	> hex_wchar_parser_type;
148
149	// the rule for a character literal
150	ch_lit
151	= eps_p[self.value = val(0), self.long_lit = val(false)]
152	>> !ch_p('L')[self.long_lit = val(true)]
153	>> ch_p('\'')
154	>> +( (
155	ch_p('\\')
156	>> ( ch_p('a') // BEL
157	[
158	impl::compose(self.value, self.long_lit,
159	var(self.overflow), val(0x07))
160	]
161	\| ch_p('b') // BS
162	[
163	impl::compose(self.value, self.long_lit,
164	var(self.overflow), val(0x08))
165	]
166	\| ch_p('t') // HT
167	[
168	impl::compose(self.value, self.long_lit,
169	var(self.overflow), val(0x09))
170	]
171	\| ch_p('n') // NL
172	[
173	impl::compose(self.value, self.long_lit,
174	var(self.overflow), val(0x0a))
175	]
176	\| ch_p('v') // VT
177	[
178	impl::compose(self.value, self.long_lit,
179	var(self.overflow), val(0x0b))
180	]
181	\| ch_p('f') // FF
182	[
183	impl::compose(self.value, self.long_lit,
184	var(self.overflow), val(0x0c))
185	]
186	\| ch_p('r') // CR
187	[
188	impl::compose(self.value, self.long_lit,
189	var(self.overflow), val(0x0d))
190	]
191	\| ch_p('?')
192	[
193	impl::compose(self.value, self.long_lit,
194	var(self.overflow), val('?'))
195	]
196	\| ch_p('\'')
197	[
198	impl::compose(self.value, self.long_lit,
199	var(self.overflow), val('\''))
200	]
201	\| ch_p('\"')
202	[
203	impl::compose(self.value, self.long_lit,
204	var(self.overflow), val('\"'))
205	]
206	\| ch_p('\\')
207	[
208	impl::compose(self.value, self.long_lit,
209	var(self.overflow), val('\\'))
210	]
211	\| ch_p('x')
212	>> if_p(self.long_lit)
213	[
214	hex_wchar_parser_type()
215	[
216	impl::compose(self.value, self.long_lit,
217	var(self.overflow), arg1)
218	]
219	]
220	.else_p
221	[
222	hex_char_parser_type()
223	[
224	impl::compose(self.value, self.long_lit,
225	var(self.overflow), arg1)
226	]
227	]
228	\| ch_p('u')
229	>> uint_parser<unsigned int, 16, 4, 4>()
230	[
231	impl::compose(self.value, self.long_lit,
232	var(self.overflow), arg1)
233	]
234	\| ch_p('U')
235	>> uint_parser<unsigned int, 16, 8, 8>()
236	[
237	impl::compose(self.value, self.long_lit,
238	var(self.overflow), arg1)
239	]
240	\| uint_parser<unsigned int, 8, 1, 3>()
241	[
242	impl::compose(self.value, self.long_lit,
243	var(self.overflow), arg1)
244	]
245	)
246	)
247	\| ~eps_p(ch_p('\'')) >> anychar_p
248	[
249	impl::compose(self.value, self.long_lit,
250	var(self.overflow), arg1)
251	]
252	)
253	>> ch_p('\'')
254	;
255
256	BOOST_SPIRIT_DEBUG_TRACE_RULE(ch_lit, TRACE_CHLIT_GRAMMAR);
257	}
258
259	// start rule of this grammar
260	rule_t const& start() const
261	{ return ch_lit; }
262	};
263
264	// flag signaling integer overflow during value composition
265	mutable bool overflow;
266	};
267
268	#undef TRACE_CHLIT_GRAMMAR
269
270	///////////////////////////////////////////////////////////////////////////////
271	//
272	// The following function is defined here, to allow the separation of
273	// the compilation of the intlit_grammap from the function using it.
274	//
275	///////////////////////////////////////////////////////////////////////////////
276
277	#if BOOST_WAVE_SEPARATE_GRAMMAR_INSTANTIATION != 0
278	#define BOOST_WAVE_CHLITGRAMMAR_GEN_INLINE
279	#else
280	#define BOOST_WAVE_CHLITGRAMMAR_GEN_INLINE inline
281	#endif
282
283	template <typename TokenT>
284	BOOST_WAVE_CHLITGRAMMAR_GEN_INLINE
285	unsigned int
286	chlit_grammar_gen<TokenT>::evaluate(TokenT const &token)
287	{
288	using namespace boost::spirit;
289
290	chlit_grammar g;
291	boost::uint32_t result = 0;
292	typename TokenT::string_type const &token_val = token.get_value();
293	parse_info<typename TokenT::string_type::const_iterator> hit =
294	parse(token_val.begin(), token_val.end(), g[spirit_assign_actor(result)]);
295
296	if (!hit.hit) {
297	BOOST_WAVE_THROW(preprocess_exception, ill_formed_character_literal,
298	token_val.c_str(), token.get_position());
299	}
300	else {
301	// range check
302	if ('L' == token_val[0]) {
303	// recognised wide character
304	if (g.overflow \|\|
305	result > (unsigned long)(std::numeric_limits<wchar_t>::max)())
306	{
307	// out of range
308	BOOST_WAVE_THROW(preprocess_exception,
309	character_literal_out_of_range,
310	token_val.c_str(), token.get_position());
311	}
312	}
313	else {
314	// recognised narrow ('normal') character
315	if (g.overflow \|\|
316	result > (unsigned long)(std::numeric_limits<unsigned char>::max)())
317	{
318	// out of range
319	BOOST_WAVE_THROW(preprocess_exception,
320	character_literal_out_of_range,
321	token_val.c_str(), token.get_position());
322	}
323	}
324	}
325	return result;
326	}
327
328	#undef BOOST_WAVE_CHLITGRAMMAR_GEN_INLINE
329
330	///////////////////////////////////////////////////////////////////////////////
331	} // namespace grammars
332	} // namespace wave
333	} // namespace boost
334
335	#endif // !defined(CPP_CHLIT_GRAMMAR_HPP_9527D349_6592_449A_A409_42A001E6C64C_INCLUDED)

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