summaryrefslogtreecommitdiff
path: root/lab/parser.py
blob: 1a679e8c65580ea074a14c5891b1a9993d5fb335 (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
# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
# For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt

"""Parser.py: a main for invoking code in coverage/parser.py"""

from __future__ import division

import glob, os, sys
import collections
from optparse import OptionParser

import disgen

from coverage.misc import CoverageException
from coverage.parser import ByteParser, PythonParser
from coverage.python import get_python_source

opcode_counts = collections.Counter()


class ParserMain(object):
    """A main for code parsing experiments."""

    def main(self, args):
        """A main function for trying the code from the command line."""

        parser = OptionParser()
        parser.add_option(
            "-c", action="store_true", dest="chunks",
            help="Show basic block chunks"
            )
        parser.add_option(
            "-d", action="store_true", dest="dis",
            help="Disassemble"
            )
        parser.add_option(
            "-H", action="store_true", dest="histogram",
            help="Count occurrences of opcodes"
            )
        parser.add_option(
            "-R", action="store_true", dest="recursive",
            help="Recurse to find source files"
            )
        parser.add_option(
            "-s", action="store_true", dest="source",
            help="Show analyzed source"
            )
        parser.add_option(
            "-t", action="store_true", dest="tokens",
            help="Show tokens"
            )

        options, args = parser.parse_args()
        if options.recursive:
            if args:
                root = args[0]
            else:
                root = "."
            for root, _, _ in os.walk(root):
                for f in glob.glob(root + "/*.py"):
                    self.one_file(options, f)
        elif not args:
            parser.print_help()
        else:
            self.one_file(options, args[0])

        if options.histogram:
            total = sum(opcode_counts.values())
            print("{0} total opcodes".format(total))
            for opcode, number in opcode_counts.most_common():
                print("{0:20s} {1:6d}  {2:.1%}".format(opcode, number, number/total))

    def one_file(self, options, filename):
        """Process just one file."""

        try:
            text = get_python_source(filename)
            bp = ByteParser(text, filename=filename)
        except Exception as err:
            print("%s" % (err,))
            return

        if options.dis:
            print("Main code:")
            self.disassemble(bp, histogram=options.histogram)

        arcs = bp._all_arcs()
        if options.chunks:
            chunks = bp._all_chunks()
            if options.recursive:
                print("%6d: %s" % (len(chunks), filename))
            else:
                print("Chunks: %r" % chunks)
                print("Arcs: %r" % sorted(arcs))

        if options.source or options.tokens:
            cp = PythonParser(filename=filename, exclude=r"no\s*cover")
            cp.show_tokens = options.tokens
            cp.parse_source()

            if options.source:
                arc_width = 0
                arc_chars = {}
                if options.chunks:
                    arc_chars = self.arc_ascii_art(arcs)
                    if arc_chars:
                        arc_width = max(len(a) for a in arc_chars.values())

                exit_counts = cp.exit_counts()

                for lineno, ltext in enumerate(cp.lines, start=1):
                    m0 = m1 = m2 = m3 = a = ' '
                    if lineno in cp.statements:
                        m0 = '='
                    elif lineno in cp.raw_statements:
                        m0 = '-'
                    exits = exit_counts.get(lineno, 0)
                    if exits > 1:
                        m1 = str(exits)
                    if lineno in cp.raw_docstrings:
                        m2 = '"'
                    if lineno in cp.raw_classdefs:
                        m2 = 'C'
                    if lineno in cp.raw_excluded:
                        m3 = 'x'
                    a = arc_chars[lineno].ljust(arc_width)
                    print("%4d %s%s%s%s%s %s" % (lineno, m0, m1, m2, m3, a, ltext))

    def disassemble(self, byte_parser, histogram=False):
        """Disassemble code, for ad-hoc experimenting."""

        for bp in byte_parser.child_parsers():
            chunks = bp._split_into_chunks()
            chunkd = dict((chunk.byte, chunk) for chunk in chunks)
            if bp.text:
                srclines = bp.text.splitlines()
            else:
                srclines = None
            print("\n%s: " % bp.code)
            upto = None
            for disline in disgen.disgen(bp.code):
                if histogram:
                    opcode_counts[disline.opcode] += 1
                    continue
                if disline.first:
                    if srclines:
                        upto = upto or disline.lineno-1
                        while upto <= disline.lineno-1:
                            print("%100s%s" % ("", srclines[upto]))
                            upto += 1
                    elif disline.offset > 0:
                        print("")
                line = disgen.format_dis_line(disline)
                chunk = chunkd.get(disline.offset)
                if chunk:
                    chunkstr = ":: %r" % chunk
                else:
                    chunkstr = ""
                print("%-70s%s" % (line, chunkstr))

        print("")

    def arc_ascii_art(self, arcs):
        """Draw arcs as ascii art.

        Returns a dictionary mapping line numbers to ascii strings to draw for
        that line.

        """

        arc_chars = collections.defaultdict(str)
        for lfrom, lto in sorted(arcs):
            if lfrom < 0:
                arc_chars[lto] += 'v'
            elif lto < 0:
                arc_chars[lfrom] += '^'
            else:
                if lfrom == lto - 1:
                    # Don't show obvious arcs.
                    continue
                if lfrom < lto:
                    l1, l2 = lfrom, lto
                else:
                    l1, l2 = lto, lfrom
                #w = max(len(arc_chars[l]) for l in range(l1, l2+1))
                w = first_all_blanks(arc_chars[l] for l in range(l1, l2+1))
                for l in range(l1, l2+1):
                    if l == lfrom:
                        ch = '<'
                    elif l == lto:
                        ch = '>'
                    else:
                        ch = '|'
                    arc_chars[l] = set_char(arc_chars[l], w, ch)

        return arc_chars


def set_char(s, n, c):
    """Set the nth char of s to be c, extending s if needed."""
    s = s.ljust(n)
    return s[:n] + c + s[n+1:]


def blanks(s):
    """Return the set of positions where s is blank."""
    return set(i for i, c in enumerate(s) if c == " ")


def first_all_blanks(ss):
    """Find the first position that is all blank in the strings ss."""
    ss = list(ss)
    blankss = blanks(ss[0])
    for s in ss[1:]:
        blankss &= blanks(s)
    if blankss:
        return min(blankss)
    else:
        return max(len(s) for s in ss)


if __name__ == '__main__':
    ParserMain().main(sys.argv[1:])