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1#!/usr/bin/env python
2
3# (C) Copyright IBM Corporation 2005
4# All Rights Reserved.
5#
6# Permission is hereby granted, free of charge, to any person obtaining a
7# copy of this software and associated documentation files (the "Software"),
8# to deal in the Software without restriction, including without limitation
9# on the rights to use, copy, modify, merge, publish, distribute, sub
10# license, and/or sell copies of the Software, and to permit persons to whom
11# the Software is furnished to do so, subject to the following conditions:
12#
13# The above copyright notice and this permission notice (including the next
14# paragraph) shall be included in all copies or substantial portions of the
15# Software.
16#
17# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
20# IBM AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
23# IN THE SOFTWARE.
24#
25# Authors:
26#    Ian Romanick <idr@us.ibm.com>
27
28import string, copy
29
30class type_node:
31	def __init__(self):
32		self.pointer = 0  # bool
33		self.const = 0    # bool
34		self.signed = 1   # bool
35		self.integer = 1  # bool
36
37		# If elements is set to non-zero, then field is an array.
38		self.elements = 0
39
40		self.name = None
41		self.size = 0     # type's size in bytes
42		return
43
44
45	def string(self):
46		"""Return string representation of this type_node."""
47		s = ""
48
49		if self.pointer:
50			s = "* "
51
52		if self.const:
53			s += "const "
54
55		if not self.pointer:
56			if self.integer:
57				if self.signed:
58					s += "signed "
59				else:
60					s += "unsigned "
61
62			if self.name:
63				s += "%s " % (self.name)
64
65		return s
66
67
68class type_table:
69	def __init__(self):
70		self.types_by_name = {}
71		return
72
73
74	def add_type(self, type_expr):
75		self.types_by_name[ type_expr.get_base_name() ] = type_expr
76		return
77
78
79	def find_type(self, name):
80		if name in self.types_by_name:
81			return self.types_by_name[ name ]
82		else:
83			return None
84
85
86def create_initial_types():
87	tt = type_table()
88
89	basic_types = [
90		("char",   1, 1),
91		("short",  2, 1),
92		("int",    4, 1),
93		("long",   4, 1),
94		("float",  4, 0),
95		("double", 8, 0),
96		("enum",   4, 1)
97	]
98
99	for (type_name, type_size, integer) in basic_types:
100		te = type_expression(None)
101		tn = type_node()
102		tn.name = type_name
103		tn.size = type_size
104		tn.integer = integer
105		te.expr.append(tn)
106		tt.add_type( te )
107
108	type_expression.built_in_types = tt
109	return
110
111
112class type_expression:
113	built_in_types = None
114
115	def __init__(self, type_string, extra_types = None):
116		self.expr = []
117
118		if not type_string:
119			return
120
121		self.original_string = type_string
122
123		if not type_expression.built_in_types:
124			raise RuntimeError("create_initial_types must be called before creating type_expression objects.")
125
126		# Replace '*' with ' * ' in type_string.  Then, split the string
127		# into tokens, separated by spaces.
128		tokens = string.split( string.replace( type_string, "*", " * " ) )
129
130		const = 0
131		t = None
132		signed = 0
133		unsigned = 0
134
135		for i in tokens:
136			if i == "const":
137				if t and t.pointer:
138					t.const = 1
139				else:
140					const = 1
141			elif i == "signed":
142				signed = 1
143			elif i == "unsigned":
144				unsigned = 1
145			elif i == "*":
146				# This is a quirky special-case because of the
147				# way the C works for types.  If 'unsigned' is
148				# specified all by itself, it is treated the
149				# same as "unsigned int".
150
151				if unsigned:
152					self.set_base_type( "int", signed, unsigned, const, extra_types )
153					const = 0
154					signed = 0
155					unsigned = 0
156
157				if not self.expr:
158					raise RuntimeError("Invalid type expression (dangling pointer)")
159
160				if signed:
161					raise RuntimeError("Invalid type expression (signed / unsigned applied to pointer)")
162
163				t = type_node()
164				t.pointer = 1
165				self.expr.append( t )
166			else:
167				if self.expr:
168					raise RuntimeError('Invalid type expression (garbage after pointer qualifier -> "%s")' % (self.original_string))
169
170				self.set_base_type( i, signed, unsigned, const, extra_types )
171				const = 0
172				signed = 0
173				unsigned = 0
174
175			if signed and unsigned:
176				raise RuntimeError("Invalid type expression (both signed and unsigned specified)")
177
178
179		if const:
180			raise RuntimeError("Invalid type expression (dangling const)")
181
182		if unsigned:
183			raise RuntimeError("Invalid type expression (dangling signed)")
184
185		if signed:
186			raise RuntimeError("Invalid type expression (dangling unsigned)")
187
188		return
189
190
191	def set_base_type(self, type_name, signed, unsigned, const, extra_types):
192		te = type_expression.built_in_types.find_type( type_name )
193		if not te:
194			te = extra_types.find_type( type_name )
195
196		if not te:
197			raise RuntimeError('Unknown base type "%s".' % (type_name))
198
199		self.expr = copy.deepcopy(te.expr)
200
201		t = self.expr[ len(self.expr) - 1 ]
202		t.const = const
203		if signed:
204			t.signed = 1
205		elif unsigned:
206			t.signed = 0
207
208
209	def set_base_type_node(self, tn):
210		self.expr = [tn]
211		return
212
213
214	def set_elements(self, count):
215		tn = self.expr[0]
216
217		tn.elements = count
218		return
219
220
221	def string(self):
222		s = ""
223		for t in self.expr:
224			s += t.string()
225
226		return s
227
228
229	def get_base_type_node(self):
230		return self.expr[0]
231
232
233	def get_base_name(self):
234		if len(self.expr):
235			return self.expr[0].name
236		else:
237			return None
238
239
240	def get_element_size(self):
241		tn = self.expr[0]
242
243		if tn.elements:
244			return tn.elements * tn.size
245		else:
246			return tn.size
247
248
249	def get_element_count(self):
250		tn = self.expr[0]
251		return tn.elements
252
253
254	def get_stack_size(self):
255		tn = self.expr[ -1 ]
256
257		if tn.elements or tn.pointer:
258			return 4
259		elif not tn.integer:
260			return tn.size
261		else:
262			return 4
263
264
265	def is_pointer(self):
266		tn = self.expr[ -1 ]
267		return tn.pointer
268
269
270	def format_string(self):
271		tn = self.expr[ -1 ]
272		if tn.pointer:
273			return "%p"
274		elif not tn.integer:
275			return "%f"
276		else:
277			return "%d"
278
279
280
281if __name__ == '__main__':
282
283	types_to_try = [ "int", "int *", "const int *", "int * const", "const int * const", \
284	                 "unsigned * const *", \
285			 "float", "const double", "double * const"]
286
287	create_initial_types()
288
289	for t in types_to_try:
290		print 'Trying "%s"...' % (t)
291		te = type_expression( t )
292		print 'Got "%s" (%u, %u).' % (te.string(), te.get_stack_size(), te.get_element_size())
293