blob: 7d9f592dfadfbc882866d8d7b7f2707edc1b646e [file] [log] [blame]
"""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
class Writer(object):
def __init__(self, output, width=78):
self.output = output
self.width = width
def newline(self):
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:
if isinstance(value, list):
value = ' '.join(value)
self._line('%s = %s' % (key, value), indent)
def rule(self, name, command, description=None, depfile=None,
self._line('rule %s' % name)
self.variable('command', escape(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)
def build(self, outputs, rule, inputs=None, implicit=None, order_only=None,
outputs = self._as_list(outputs)
all_inputs = self._as_list(inputs)[:]
if implicit:
if order_only:
self._line('build %s: %s %s' % (' '.join(outputs),
' '.join(all_inputs)))
if variables:
for key, val in variables:
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 _line(self, text, indent=0):
"""Write 'text' word-wrapped at self.width characters."""
leading_space = ' ' * indent
while len(text) > self.width:
# The text is too wide; wrap if possible.
# Find the rightmost space that would obey our width constraint.
available_space = self.width - len(leading_space) - len(' $')
space = text.rfind(' ', 0, available_space)
if space < 0:
# No such space; just use the first space we can find.
space = text.find(' ', available_space)
if space < 0:
# Give up on breaking.
self.output.write(leading_space + text[0:space] + ' $\n')
text = text[space+1:]
# Subsequent lines are continuations, so indent them.
leading_space = ' ' * (indent+2)
self.output.write(leading_space + text + '\n')
def _as_list(self, input):
if input is None:
return []
if isinstance(input, list):
return input
return [input]
def escape(string):
"""Escape a string such that Makefile and shell variables are
correctly escaped for use in a Ninja file.
assert '\n' not in string, 'Ninja syntax does not allow newlines'
# We only have one special metacharacter: '$'.
# We should leave $in and $out untouched.
# Just look for makefile/shell style substitutions
return re.sub(r'(\$[{(][a-z_]+[})])',