| Peter Collingbourne | d5395fb | 2012-01-08 22:09:58 +0000 | [diff] [blame^] | 1 | #!/usr/bin/python |
| 2 | |
| 3 | """Python module for generating .ninja files. |
| 4 | |
| 5 | Note that this is emphatically not a required piece of Ninja; it's |
| 6 | just a helpful utility for build-file-generation systems that already |
| 7 | use Python. |
| 8 | """ |
| 9 | |
| 10 | import textwrap |
| 11 | |
| 12 | class Writer(object): |
| 13 | def __init__(self, output, width=78): |
| 14 | self.output = output |
| 15 | self.width = width |
| 16 | |
| 17 | def newline(self): |
| 18 | self.output.write('\n') |
| 19 | |
| 20 | def comment(self, text): |
| 21 | for line in textwrap.wrap(text, self.width - 2): |
| 22 | self.output.write('# ' + line + '\n') |
| 23 | |
| 24 | def variable(self, key, value, indent=0): |
| 25 | if value is None: |
| 26 | return |
| 27 | if isinstance(value, list): |
| 28 | value = ' '.join(value) |
| 29 | self._line('%s = %s' % (key, value), indent) |
| 30 | |
| 31 | def rule(self, name, command, description=None, depfile=None, |
| 32 | generator=False): |
| 33 | self._line('rule %s' % name) |
| 34 | self.variable('command', command, indent=1) |
| 35 | if description: |
| 36 | self.variable('description', description, indent=1) |
| 37 | if depfile: |
| 38 | self.variable('depfile', depfile, indent=1) |
| 39 | if generator: |
| 40 | self.variable('generator', '1', indent=1) |
| 41 | |
| 42 | def build(self, outputs, rule, inputs=None, implicit=None, order_only=None, |
| 43 | variables=None): |
| 44 | outputs = self._as_list(outputs) |
| 45 | all_inputs = self._as_list(inputs)[:] |
| 46 | |
| 47 | if implicit: |
| 48 | all_inputs.append('|') |
| 49 | all_inputs.extend(self._as_list(implicit)) |
| 50 | if order_only: |
| 51 | all_inputs.append('||') |
| 52 | all_inputs.extend(self._as_list(order_only)) |
| 53 | |
| 54 | self._line('build %s: %s %s' % (' '.join(outputs), |
| 55 | rule, |
| 56 | ' '.join(all_inputs))) |
| 57 | |
| 58 | if variables: |
| 59 | for key, val in variables: |
| 60 | self.variable(key, val, indent=1) |
| 61 | |
| 62 | return outputs |
| 63 | |
| 64 | def include(self, path): |
| 65 | self._line('include %s' % path) |
| 66 | |
| 67 | def subninja(self, path): |
| 68 | self._line('subninja %s' % path) |
| 69 | |
| 70 | def default(self, paths): |
| 71 | self._line('default %s' % ' '.join(self._as_list(paths))) |
| 72 | |
| 73 | def _line(self, text, indent=0): |
| 74 | """Write 'text' word-wrapped at self.width characters.""" |
| 75 | leading_space = ' ' * indent |
| 76 | while len(text) > self.width: |
| 77 | # The text is too wide; wrap if possible. |
| 78 | |
| 79 | # Find the rightmost space that would obey our width constraint. |
| 80 | available_space = self.width - len(leading_space) - len(' $') |
| 81 | space = text.rfind(' ', 0, available_space) |
| 82 | if space < 0: |
| 83 | # No such space; just use the first space we can find. |
| 84 | space = text.find(' ', available_space) |
| 85 | if space < 0: |
| 86 | # Give up on breaking. |
| 87 | break |
| 88 | |
| 89 | self.output.write(leading_space + text[0:space] + ' $\n') |
| 90 | text = text[space+1:] |
| 91 | |
| 92 | # Subsequent lines are continuations, so indent them. |
| 93 | leading_space = ' ' * (indent+2) |
| 94 | |
| 95 | self.output.write(leading_space + text + '\n') |
| 96 | |
| 97 | def _as_list(self, input): |
| 98 | if input is None: |
| 99 | return [] |
| 100 | if isinstance(input, list): |
| 101 | return input |
| 102 | return [input] |
| 103 | |
| 104 | |
| 105 | def escape(string): |
| 106 | """Escape a string such that it can be embedded into a Ninja file without |
| 107 | further interpretation.""" |
| 108 | assert '\n' not in string, 'Ninja syntax does not allow newlines' |
| 109 | # We only have one special metacharacter: '$'. |
| 110 | return string.replace('$', '$$') |