Python code coverage for Tools/clinic/cpp.py

#	count	content
1	n/a	import re
2	n/a	import sys
3	n/a
4	n/a	def negate(condition):
5	n/a	"""
6	n/a	Returns a CPP conditional that is the opposite of the conditional passed in.
7	n/a	"""
8	n/a	if condition.startswith('!'):
9	n/a	return condition[1:]
10	n/a	return "!" + condition
11	n/a
12	n/a	class Monitor:
13	n/a	"""
14	n/a	A simple C preprocessor that scans C source and computes, line by line,
15	n/a	what the current C preprocessor #if state is.
16	n/a
17	n/a	Doesn't handle everything--for example, if you have /* inside a C string,
18	n/a	without a matching / (also inside a C string), or with a / inside a C
19	n/a	string but on another line and with preprocessor macros in between...
20	n/a	the parser will get lost.
21	n/a
22	n/a	Anyway this implementation seems to work well enough for the CPython sources.
23	n/a	"""
24	n/a
25	n/a	is_a_simple_defined = re.compile(r'^defined\s$\s[A-Za-z0-9_]+\s*$$').match
26	n/a
27	n/a	def __init__(self, filename=None, *, verbose=False):
28	n/a	self.stack = []
29	n/a	self.in_comment = False
30	n/a	self.continuation = None
31	n/a	self.line_number = 0
32	n/a	self.filename = filename
33	n/a	self.verbose = verbose
34	n/a
35	n/a	def __repr__(self):
36	n/a	return ''.join((
37	n/a	'<Monitor ',
38	n/a	str(id(self)),
39	n/a	" line=", str(self.line_number),
40	n/a	" condition=", repr(self.condition()),
41	n/a	">"))
42	n/a
43	n/a	def status(self):
44	n/a	return str(self.line_number).rjust(4) + ": " + self.condition()
45	n/a
46	n/a	def condition(self):
47	n/a	"""
48	n/a	Returns the current preprocessor state, as a single #if condition.
49	n/a	"""
50	n/a	return " && ".join(condition for token, condition in self.stack)
51	n/a
52	n/a	def fail(self, *a):
53	n/a	if self.filename:
54	n/a	filename = " " + self.filename
55	n/a	else:
56	n/a	filename = ''
57	n/a	print("Error at" + filename, "line", self.line_number, ":")
58	n/a	print(" ", ' '.join(str(x) for x in a))
59	n/a	sys.exit(-1)
60	n/a
61	n/a	def close(self):
62	n/a	if self.stack:
63	n/a	self.fail("Ended file while still in a preprocessor conditional block!")
64	n/a
65	n/a	def write(self, s):
66	n/a	for line in s.split("\n"):
67	n/a	self.writeline(line)
68	n/a
69	n/a	def writeline(self, line):
70	n/a	self.line_number += 1
71	n/a	line = line.strip()
72	n/a
73	n/a	def pop_stack():
74	n/a	if not self.stack:
75	n/a	self.fail("#" + token + " without matching #if / #ifdef / #ifndef!")
76	n/a	return self.stack.pop()
77	n/a
78	n/a	if self.continuation:
79	n/a	line = self.continuation + line
80	n/a	self.continuation = None
81	n/a
82	n/a	if not line:
83	n/a	return
84	n/a
85	n/a	if line.endswith('\\'):
86	n/a	self.continuation = line[:-1].rstrip() + " "
87	n/a	return
88	n/a
89	n/a	# we have to ignore preprocessor commands inside comments
90	n/a	#
91	n/a	# we also have to handle this:
92	n/a	# /* start
93	n/a	# ...
94	n/a	# / / <-- tricky!
95	n/a	# ...
96	n/a	# */
97	n/a	# and this:
98	n/a	# /* start
99	n/a	# ...
100	n/a	# / / also tricky! */
101	n/a	if self.in_comment:
102	n/a	if '*/' in line:
103	n/a	# snip out the comment and continue
104	n/a	#
105	n/a	# GCC allows
106	n/a	# /* comment
107	n/a	# */ #include <stdio.h>
108	n/a	# maybe other compilers too?
109	n/a	_, _, line = line.partition('*/')
110	n/a	self.in_comment = False
111	n/a
112	n/a	while True:
113	n/a	if '/*' in line:
114	n/a	if self.in_comment:
115	n/a	self.fail("Nested block comment!")
116	n/a
117	n/a	before, _, remainder = line.partition('/*')
118	n/a	comment, comment_ends, after = remainder.partition('*/')
119	n/a	if comment_ends:
120	n/a	# snip out the comment
121	n/a	line = before.rstrip() + ' ' + after.lstrip()
122	n/a	continue
123	n/a	# comment continues to eol
124	n/a	self.in_comment = True
125	n/a	line = before.rstrip()
126	n/a	break
127	n/a
128	n/a	# we actually have some // comments
129	n/a	# (but block comments take precedence)
130	n/a	before, line_comment, comment = line.partition('//')
131	n/a	if line_comment:
132	n/a	line = before.rstrip()
133	n/a
134	n/a	if not line.startswith('#'):
135	n/a	return
136	n/a
137	n/a	line = line[1:].lstrip()
138	n/a	assert line
139	n/a
140	n/a	fields = line.split()
141	n/a	token = fields[0].lower()
142	n/a	condition = ' '.join(fields[1:]).strip()
143	n/a
144	n/a	if_tokens = {'if', 'ifdef', 'ifndef'}
145	n/a	all_tokens = if_tokens \| {'elif', 'else', 'endif'}
146	n/a
147	n/a	if token not in all_tokens:
148	n/a	return
149	n/a
150	n/a	# cheat a little here, to reuse the implementation of if
151	n/a	if token == 'elif':
152	n/a	pop_stack()
153	n/a	token = 'if'
154	n/a
155	n/a	if token in if_tokens:
156	n/a	if not condition:
157	n/a	self.fail("Invalid format for #" + token + " line: no argument!")
158	n/a	if token == 'if':
159	n/a	if not self.is_a_simple_defined(condition):
160	n/a	condition = "(" + condition + ")"
161	n/a	else:
162	n/a	fields = condition.split()
163	n/a	if len(fields) != 1:
164	n/a	self.fail("Invalid format for #" + token + " line: should be exactly one argument!")
165	n/a	symbol = fields[0]
166	n/a	condition = 'defined(' + symbol + ')'
167	n/a	if token == 'ifndef':
168	n/a	condition = '!' + condition
169	n/a
170	n/a	self.stack.append(("if", condition))
171	n/a	if self.verbose:
172	n/a	print(self.status())
173	n/a	return
174	n/a
175	n/a	previous_token, previous_condition = pop_stack()
176	n/a
177	n/a	if token == 'else':
178	n/a	self.stack.append(('else', negate(previous_condition)))
179	n/a	elif token == 'endif':
180	n/a	pass
181	n/a	if self.verbose:
182	n/a	print(self.status())
183	n/a
184	n/a	if __name__ == '__main__':
185	n/a	for filename in sys.argv[1:]:
186	n/a	with open(filename, "rt") as f:
187	n/a	cpp = Monitor(filename, verbose=True)
188	n/a	print()
189	n/a	print(filename)
190	n/a	for line_number, line in enumerate(f.read().split('\n'), 1):
191	n/a	cpp.writeline(line)