summaryrefslogtreecommitdiffstats
path: root/src/engine/SCons/compat/_scons_shlex.py
blob: d6c10357ad5b1beab26e65ac736d452279005515 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
# -*- coding: iso-8859-1 -*-
"""A lexical analyzer class for simple shell-like syntaxes."""

# Module and documentation by Eric S. Raymond, 21 Dec 1998
# Input stacking and error message cleanup added by ESR, March 2000
# push_source() and pop_source() made explicit by ESR, January 2001.
# Posix compliance, split(), string arguments, and
# iterator interface by Gustavo Niemeyer, April 2003.

import os.path
import sys
#from collections import deque

class deque:
    def __init__(self):
        self.data = []
    def __len__(self):
        return len(self.data)
    def appendleft(self, item):
        self.data.insert(0, item)
    def popleft(self):
        return self.data.pop(0)

try:
    basestring
except NameError:
    import types
    def is_basestring(s):
        return type(s) is types.StringType
else:
    def is_basestring(s):
        return isinstance(s, basestring)

try:
    from cStringIO import StringIO
except ImportError:
    from StringIO import StringIO

__all__ = ["shlex", "split"]

class shlex:
    "A lexical analyzer class for simple shell-like syntaxes."
    def __init__(self, instream=None, infile=None, posix=False):
        if is_basestring(instream):
            instream = StringIO(instream)
        if instream is not None:
            self.instream = instream
            self.infile = infile
        else:
            self.instream = sys.stdin
            self.infile = None
        self.posix = posix
        if posix:
            self.eof = None
        else:
            self.eof = ''
        self.commenters = '#'
        self.wordchars = ('abcdfeghijklmnopqrstuvwxyz'
                          'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_')
        if self.posix:
            self.wordchars = self.wordchars + ('ßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿ'
                               'ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞ')
        self.whitespace = ' \t\r\n'
        self.whitespace_split = False
        self.quotes = '\'"'
        self.escape = '\\'
        self.escapedquotes = '"'
        self.state = ' '
        self.pushback = deque()
        self.lineno = 1
        self.debug = 0
        self.token = ''
        self.filestack = deque()
        self.source = None
        if self.debug:
            print 'shlex: reading from %s, line %d' \
                  % (self.instream, self.lineno)

    def push_token(self, tok):
        "Push a token onto the stack popped by the get_token method"
        if self.debug >= 1:
            print "shlex: pushing token " + repr(tok)
        self.pushback.appendleft(tok)

    def push_source(self, newstream, newfile=None):
        "Push an input source onto the lexer's input source stack."
        if is_basestring(newstream):
            newstream = StringIO(newstream)
        self.filestack.appendleft((self.infile, self.instream, self.lineno))
        self.infile = newfile
        self.instream = newstream
        self.lineno = 1
        if self.debug:
            if newfile is not None:
                print 'shlex: pushing to file %s' % (self.infile,)
            else:
                print 'shlex: pushing to stream %s' % (self.instream,)

    def pop_source(self):
        "Pop the input source stack."
        self.instream.close()
        (self.infile, self.instream, self.lineno) = self.filestack.popleft()
        if self.debug:
            print 'shlex: popping to %s, line %d' \
                  % (self.instream, self.lineno)
        self.state = ' '

    def get_token(self):
        "Get a token from the input stream (or from stack if it's nonempty)"
        if self.pushback:
            tok = self.pushback.popleft()
            if self.debug >= 1:
                print "shlex: popping token " + repr(tok)
            return tok
        # No pushback.  Get a token.
        raw = self.read_token()
        # Handle inclusions
        if self.source is not None:
            while raw == self.source:
                spec = self.sourcehook(self.read_token())
                if spec:
                    (newfile, newstream) = spec
                    self.push_source(newstream, newfile)
                raw = self.get_token()
        # Maybe we got EOF instead?
        while raw == self.eof:
            if not self.filestack:
                return self.eof
            else:
                self.pop_source()
                raw = self.get_token()
        # Neither inclusion nor EOF
        if self.debug >= 1:
            if raw != self.eof:
                print "shlex: token=" + repr(raw)
            else:
                print "shlex: token=EOF"
        return raw

    def read_token(self):
        quoted = False
        escapedstate = ' '
        while True:
            nextchar = self.instream.read(1)
            if nextchar == '\n':
                self.lineno = self.lineno + 1
            if self.debug >= 3:
                print "shlex: in state", repr(self.state), \
                      "I see character:", repr(nextchar)
            if self.state is None:
                self.token = ''        # past end of file
                break
            elif self.state == ' ':
                if not nextchar:
                    self.state = None  # end of file
                    break
                elif nextchar in self.whitespace:
                    if self.debug >= 2:
                        print "shlex: I see whitespace in whitespace state"
                    if self.token or (self.posix and quoted):
                        break   # emit current token
                    else:
                        continue
                elif nextchar in self.commenters:
                    self.instream.readline()
                    self.lineno = self.lineno + 1
                elif self.posix and nextchar in self.escape:
                    escapedstate = 'a'
                    self.state = nextchar
                elif nextchar in self.wordchars:
                    self.token = nextchar
                    self.state = 'a'
                elif nextchar in self.quotes:
                    if not self.posix:
                        self.token = nextchar
                    self.state = nextchar
                elif self.whitespace_split:
                    self.token = nextchar
                    self.state = 'a'
                else:
                    self.token = nextchar
                    if self.token or (self.posix and quoted):
                        break   # emit current token
                    else:
                        continue
            elif self.state in self.quotes:
                quoted = True
                if not nextchar:      # end of file
                    if self.debug >= 2:
                        print "shlex: I see EOF in quotes state"
                    # XXX what error should be raised here?
                    raise ValueError, "No closing quotation"
                if nextchar == self.state:
                    if not self.posix:
                        self.token = self.token + nextchar
                        self.state = ' '
                        break
                    else:
                        self.state = 'a'
                elif self.posix and nextchar in self.escape and \
                     self.state in self.escapedquotes:
                    escapedstate = self.state
                    self.state = nextchar
                else:
                    self.token = self.token + nextchar
            elif self.state in self.escape:
                if not nextchar:      # end of file
                    if self.debug >= 2:
                        print "shlex: I see EOF in escape state"
                    # XXX what error should be raised here?
                    raise ValueError, "No escaped character"
                # In posix shells, only the quote itself or the escape
                # character may be escaped within quotes.
                if escapedstate in self.quotes and \
                   nextchar != self.state and nextchar != escapedstate:
                    self.token = self.token + self.state
                self.token = self.token + nextchar
                self.state = escapedstate
            elif self.state == 'a':
                if not nextchar:
                    self.state = None   # end of file
                    break
                elif nextchar in self.whitespace:
                    if self.debug >= 2:
                        print "shlex: I see whitespace in word state"
                    self.state = ' '
                    if self.token or (self.posix and quoted):
                        break   # emit current token
                    else:
                        continue
                elif nextchar in self.commenters:
                    self.instream.readline()
                    self.lineno = self.lineno + 1
                    if self.posix:
                        self.state = ' '
                        if self.token or (self.posix and quoted):
                            break   # emit current token
                        else:
                            continue
                elif self.posix and nextchar in self.quotes:
                    self.state = nextchar
                elif self.posix and nextchar in self.escape:
                    escapedstate = 'a'
                    self.state = nextchar
                elif nextchar in self.wordchars or nextchar in self.quotes \
                    or self.whitespace_split:
                    self.token = self.token + nextchar
                else:
                    self.pushback.appendleft(nextchar)
                    if self.debug >= 2:
                        print "shlex: I see punctuation in word state"
                    self.state = ' '
                    if self.token:
                        break   # emit current token
                    else:
                        continue
        result = self.token
        self.token = ''
        if self.posix and not quoted and result == '':
            result = None
        if self.debug > 1:
            if result:
                print "shlex: raw token=" + repr(result)
            else:
                print "shlex: raw token=EOF"
        return result

    def sourcehook(self, newfile):
        "Hook called on a filename to be sourced."
        if newfile[0] == '"':
            newfile = newfile[1:-1]
        # This implements cpp-like semantics for relative-path inclusion.
        if is_basestring(self.infile) and not os.path.isabs(newfile):
            newfile = os.path.join(os.path.dirname(self.infile), newfile)
        return (newfile, open(newfile, "r"))

    def error_leader(self, infile=None, lineno=None):
        "Emit a C-compiler-like, Emacs-friendly error-message leader."
        if infile is None:
            infile = self.infile
        if lineno is None:
            lineno = self.lineno
        return "\"%s\", line %d: " % (infile, lineno)

    def __iter__(self):
        return self

    def next(self):
        token = self.get_token()
        if token == self.eof:
            raise StopIteration
        return token

def split(s, comments=False):
    lex = shlex(s, posix=True)
    lex.whitespace_split = True
    if not comments:
        lex.commenters = ''
    #return list(lex)
    result = []
    while True:
        token = lex.get_token()
        if token == lex.eof:
            break
        result.append(token)
    return result

if __name__ == '__main__':
    if len(sys.argv) == 1:
        lexer = shlex()
    else:
        file = sys.argv[1]
        lexer = shlex(open(file), file)
    while 1:
        tt = lexer.get_token()
        if tt:
            print "Token: " + repr(tt)
        else:
            break