#!/usr/bin/env python3 # Copyright 2015 The Chromium Authors # Use of this source code is governed by a BSD-style license that can be # found in the LICENSE file. # This writes headers for build flags. See buildflag_header.gni for usage of # this system as a whole. # # The parameters are passed in a response file so we don't have to worry # about command line lengths. The name of the response file is passed on the # command line. # # The format of the response file is: # [--flags ] import optparse import os import re import shlex class Options: def __init__(self, output, rulename, header_guard, flags): self.output = output self.rulename = rulename self.header_guard = header_guard self.flags = flags def GetOptions(): parser = optparse.OptionParser() parser.add_option('--output', help="Output header name inside --gen-dir.") parser.add_option('--rulename', help="Helpful name of build rule for including in the " + "comment at the top of the file.") parser.add_option('--gen-dir', help="Path to root of generated file directory tree.") parser.add_option('--definitions', help="Name of the response file containing the flags.") cmdline_options, cmdline_flags = parser.parse_args() # Compute a valid C++ header guard by replacing non valid chars with '_', # upper-casing everything and prepending '_' if first symbol is digit. header_guard = cmdline_options.output.upper() if header_guard[0].isdigit(): header_guard = '_' + header_guard header_guard = re.sub('[^\w]', '_', header_guard) header_guard += '_' # The actual output file is inside the gen dir. output = os.path.join(cmdline_options.gen_dir, cmdline_options.output) # Definition file in GYP is newline separated, in GN they are shell formatted. # shlex can parse both of these. with open(cmdline_options.definitions, 'r') as def_file: defs = shlex.split(def_file.read()) flags_index = defs.index('--flags') # Everything after --flags are flags. true/false are remapped to 1/0, # everything else is passed through. flags = [] for flag in defs[flags_index + 1 :]: equals_index = flag.index('=') key = flag[:equals_index] value = flag[equals_index + 1:] # Canonicalize and validate the value. if value == 'true': value = '1' elif value == 'false': value = '0' flags.append((key, str(value))) return Options(output=output, rulename=cmdline_options.rulename, header_guard=header_guard, flags=flags) def WriteHeader(options): with open(options.output, 'w') as output_file: output_file.write("// Generated by build/write_buildflag_header.py\n") if options.rulename: output_file.write('// From "' + options.rulename + '"\n') output_file.write('\n#ifndef %s\n' % options.header_guard) output_file.write('#define %s\n\n' % options.header_guard) output_file.write('#include "build/buildflag.h" // IWYU pragma: export\n\n') for pair in options.flags: output_file.write('#define BUILDFLAG_INTERNAL_%s() (%s)\n' % pair) output_file.write('\n#endif // %s\n' % options.header_guard) options = GetOptions() WriteHeader(options)