summaryrefslogtreecommitdiffstats
path: root/misc/ninja_syntax.py
blob: ece7eb5b90ddd7df83cdd6586cfcbb9429f2a920 (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
#!/usr/bin/python

"""Python module for generating .ninja files.

Note that this is emphatically not a required piece of Ninja; it's
just a helpful utility for build-file-generation systems that already
use Python.
"""

import textwrap
import re

def escape_path(word):
    return word.replace('$ ','$$ ').replace(' ','$ ').replace(':', '$:')

class Writer(object):
    def __init__(self, output, width=78):
        self.output = output
        self.width = width

    def newline(self):
        self.output.write('\n')

    def comment(self, text):
        for line in textwrap.wrap(text, self.width - 2):
            self.output.write('# ' + line + '\n')

    def variable(self, key, value, indent=0):
        if value is None:
            return
        if isinstance(value, list):
            value = ' '.join(filter(None, value))  # Filter out empty strings.
        self._line('%s = %s' % (key, value), indent)

    def pool(self, name, depth):
        self._line('pool %s' % name)
        self.variable('depth', depth, indent=1)

    def rule(self, name, command, description=None, depfile=None,
             generator=False, pool=None, restat=False, rspfile=None,
             rspfile_content=None):
        self._line('rule %s' % name)
        self.variable('command', command, indent=1)
        if description:
            self.variable('description', description, indent=1)
        if depfile:
            self.variable('depfile', depfile, indent=1)
        if generator:
            self.variable('generator', '1', indent=1)
        if pool:
            self.variable('pool', pool, indent=1)
        if restat:
            self.variable('restat', '1', indent=1)
        if rspfile:
            self.variable('rspfile', rspfile, indent=1)
        if rspfile_content:
            self.variable('rspfile_content', rspfile_content, indent=1)

    def build(self, outputs, rule, inputs=None, implicit=None, order_only=None,
              variables=None):
        outputs = self._as_list(outputs)
        all_inputs = self._as_list(inputs)[:]
        out_outputs = list(map(escape_path, outputs))
        all_inputs = list(map(escape_path, all_inputs))

        if implicit:
            implicit = map(escape_path, self._as_list(implicit))
            all_inputs.append('|')
            all_inputs.extend(implicit)
        if order_only:
            order_only = map(escape_path, self._as_list(order_only))
            all_inputs.append('||')
            all_inputs.extend(order_only)

        self._line('build %s: %s' % (' '.join(out_outputs),
                                        ' '.join([rule] + all_inputs)))

        if variables:
            if isinstance(variables, dict):
                iterator = iter(variables.items())
            else:
                iterator = iter(variables)

            for key, val in iterator:
                self.variable(key, val, indent=1)

        return outputs

    def include(self, path):
        self._line('include %s' % path)

    def subninja(self, path):
        self._line('subninja %s' % path)

    def default(self, paths):
        self._line('default %s' % ' '.join(self._as_list(paths)))

    def _count_dollars_before_index(self, s, i):
      """Returns the number of '$' characters right in front of s[i]."""
      dollar_count = 0
      dollar_index = i - 1
      while dollar_index > 0 and s[dollar_index] == '$':
        dollar_count += 1
        dollar_index -= 1
      return dollar_count

    def _line(self, text, indent=0):
        """Write 'text' word-wrapped at self.width characters."""
        leading_space = '  ' * indent
        while len(leading_space) + len(text) > self.width:
            # The text is too wide; wrap if possible.

            # Find the rightmost space that would obey our width constraint and
            # that's not an escaped space.
            available_space = self.width - len(leading_space) - len(' $')
            space = available_space
            while True:
              space = text.rfind(' ', 0, space)
              if space < 0 or \
                 self._count_dollars_before_index(text, space) % 2 == 0:
                break

            if space < 0:
                # No such space; just use the first unescaped space we can find.
                space = available_space - 1
                while True:
                  space = text.find(' ', space + 1)
                  if space < 0 or \
                     self._count_dollars_before_index(text, space) % 2 == 0:
                    break
            if space < 0:
                # Give up on breaking.
                break

            self.output.write(leading_space + text[0:space] + ' $\n')
            text = text[space+1:]

            # Subsequent lines are continuations, so indent them.
            leading_space = '  ' * (indent+2)

        self.output.write(leading_space + text + '\n')

    def _as_list(self, input):
        if input is None:
            return []
        if isinstance(input, list):
            return input
        return [input]


def escape(string):
    """Escape a string such that it can be embedded into a Ninja file without
    further interpretation."""
    assert '\n' not in string, 'Ninja syntax does not allow newlines'
    # We only have one special metacharacter: '$'.
    return string.replace('$', '$$')