export.py

#!/usr/bin/env python3
import json
import os
import pipes
from optparse import OptionParser

import make

def rule_to_json(rule):
    return {
        'targets': rule.targets,
        'deps': rule.deps,
        'cwd': rule.cwd,
        'cmds': rule.cmds,
        'd_file': rule.d_file,
        'order_only_deps': rule.order_only_deps,
        'msvc_show_includes': rule.msvc_show_includes,
        'stdout_filter': rule.stdout_filter,
        'latency': rule.latency,
    }

def path_strip(prefix, path):
    if not prefix.endswith('/'):
        prefix += '/'
    if path.startswith(prefix):
        path = path[len(prefix):]
    return path

# Escape a path for use inside a Makefile. No idea if this is good enough...
def makefile_esc(path):
    if ':' in path:
        print('ERROR: Make cannot handle paths with colons: %r' % path)
        exit(1)
    return path.replace('\\', '\\\\').replace(' ', '\\ ')

def rule_to_makefile(fp, rule):
    # targets
    target_list = [path_strip(rule.cwd, p) for p in rule.targets]
    targets = ' '.join(map(makefile_esc, target_list))
    # deps
    deps = ' '.join([makefile_esc(path_strip(rule.cwd, p)) for p in rule.deps])
    # cmds
    cmd_list = rule.cmds[:]
    target_dirs = {os.path.dirname(t) for t in target_list}
    target_dirs.discard('')
    if target_dirs:
        # Create target directories
        cmd_list.insert(0, ['mkdir', '-p'] + list(target_dirs))
    cmds = '\n\t'.join([' '.join([pipes.quote(arg) for arg in cmd]) for cmd in cmd_list])
    # recipe
    fp.write('%s: %s\n\t%s\n\n' % (targets, deps, cmds))
    # d_file
    if rule.d_file:
        fp.write('-include %s\n\n' % (path_strip(rule.cwd, rule.d_file),))

def main():
    # Parse command line. This is a copied+pasted subset of options from make.py, but oh well
    parser = OptionParser()
    parser.add_option('-f', dest='files', action='append', help='specify the path to a rules.py file (default is "rules.py")', metavar='FILE')
    parser.add_option('-v', dest='verbose', action='store_true', help='print verbose build output')
    parser.add_option('--var', dest='vars', type='str', action='append', default=[], metavar='KEY=VALUE',
            help='option in the form key=value, sets a variable in the ctx.vars dictionary for passing to rules')
    parser.add_option('--json', dest='json', type='str', metavar='JSON_FILE',
            help='dump build rules to the given file in JSON format')
    parser.add_option('--makefile', dest='makefile', type='str', help='generate a gnu makefile', metavar='MAKEFILE')
    (options, args) = parser.parse_args()
    assert not args
    if not options.makefile and not options.json:
        print("ERROR: must specify either --json or --makefile")
        exit(1)
    if options.files is None:
        options.files = ['rules.py'] # default to "-f rules.py"
    cwd = os.getcwd()

    # Set up rule DB, reading in make.db files as we go
    ctx = make.BuildContext(options.vars)
    visited_rules_files = set()
    for f in options.files:
        make.parse_rules_py(ctx, options, make.normpath(make.joinpath(cwd, f)), visited_rules_files)

    # Generate Makefile
    if options.makefile:
        with open(options.makefile, 'wt', encoding='utf-8') as f:
            f.write('# Automatically generated by make.py from %s\n\n' % (options.files,))
            for rule in make.rules.values():
                rule_to_makefile(f, rule)

    if options.json:
        # rules is a dictionary that can have the same rule as a value under multiple targets,
        # so make a set
        all_rules = set(make.rules.values())
        all_rules = [rule_to_json(rule) for rule in sorted(all_rules, key=lambda r: tuple(r.targets))]
        all_rules = {'rules': all_rules}
        with open(options.json, 'w') as f:
            json.dump(all_rules, f, sort_keys=True, indent=2)

if __name__ == '__main__':
    main()