#!/usr/bin/env python3

#

# Tweaks a compile_commands.json file: for every build command that has a

# --sysroot argument, each existing -isystem argument gets a matching extra

# -isystem argument pointing into the sysroot, and the --sysroot argument

# itself is then removed. This is useful when a compiler resolves -isystem

# paths relative to --sysroot internally (as part of its built-in search

# path handling) but a tool consuming compile_commands.json (such as

# Cppcheck) does not, so the sysroot-relative path needs to be spelled out

# explicitly instead.

#

# Example:

# --sysroot /a/b -isystem /opt/x

# =>

# -isystem /opt/x -isystem /a/b/opt/x

#

# Optionally, --isystem-to-i converts -isystem arguments to -I, which can be

# useful since Cppcheck otherwise treats -isystem headers as "system"

# headers and skips some checks in them. Paths whose folder name matches one

# of the --exclude-folder values are left as -isystem. For example, with

# --isystem-to-i --exclude-folder lib1:

# -isystem /opt/x -isystem /path/lib1/include

# =>

# -I /opt/x -isystem /path/lib1/include

#

# Optionally, --remove-include-path removes -I arguments whose path contains

# the given path. For example, with --remove-include-path /path/lib1:

# -I /opt/x -I /path/lib1/include

# =>

# -I /opt/x

#

# Usage:

# tools/tweak-compile-commands.py compile_commands.json -o out.json

# tools/tweak-compile-commands.py -i compile_commands.json

# tools/tweak-compile-commands.py -i compile_commands.json --isystem-to-i --exclude-folder lib1

# tools/tweak-compile-commands.py -i compile_commands.json --remove-include-path /path/lib1

#

# With neither -o nor -i, the result is written to stdout.

import argparse

import json

import shlex

import sys

def find_sysroot(tokens):

for i, tok in enumerate(tokens):

if tok == '--sysroot' and i + 1 < len(tokens):

return tokens[i + 1]

if tok.startswith('--sysroot='):

return tok[len('--sysroot='):]

return None

def join_sysroot(sysroot, path):

return sysroot.rstrip('/') + '/' + path.lstrip('/')

def remove_sysroot_arg(tokens):

result = []

i = 0

n = len(tokens)

while i < n:

tok = tokens[i]

if tok == '--sysroot' and i + 1 < n:

i += 2

continue

if tok.startswith('--sysroot='):

i += 1

continue

result.append(tok)

i += 1

return result

def add_isystem_sysroot(tokens, sysroot):

result = []

i = 0

n = len(tokens)

while i < n:

tok = tokens[i]

if tok == '-isystem' and i + 1 < n:

path = tokens[i + 1]

result.append(tok)

result.append(path)

result.append('-isystem')

result.append(join_sysroot(sysroot, path))

i += 2

continue

if tok.startswith('-isystem') and tok != '-isystem':

path = tok[len('-isystem'):]

result.append(tok)

result.append('-isystem' + join_sysroot(sysroot, path))

i += 1

continue

result.append(tok)

i += 1

return result

def is_excluded(path, exclude_folders):

parts = path.replace('\\', '/').split('/')

return any(part in exclude_folders for part in parts if part)

def convert_isystem_to_i(tokens, exclude_folders):

result = []

i = 0

n = len(tokens)

while i < n:

tok = tokens[i]

if tok == '-isystem' and i + 1 < n:

path = tokens[i + 1]

result.append(tok if is_excluded(path, exclude_folders) else '-I')

result.append(path)

i += 2

continue

if tok.startswith('-isystem') and tok != '-isystem':

path = tok[len('-isystem'):]

result.append(tok if is_excluded(path, exclude_folders) else '-I' + path)

i += 1

continue

result.append(tok)

i += 1

return result

def matches_remove_path(path, remove_paths):

normalized = path.replace('\\', '/')

return any(remove_path.replace('\\', '/') in normalized for remove_path in remove_paths)

def remove_include_paths(tokens, remove_paths):

result = []

i = 0

n = len(tokens)

while i < n:

tok = tokens[i]

if tok == '-I' and i + 1 < n:

path = tokens[i + 1]

if matches_remove_path(path, remove_paths):

i += 2

continue

result.append(tok)

result.append(path)

i += 2

continue

if tok.startswith('-I') and tok != '-I':

path = tok[len('-I'):]

if matches_remove_path(path, remove_paths):

i += 1

continue

result.append(tok)

i += 1

continue

result.append(tok)

i += 1

return result

def tweak_entry(entry, isystem_to_i, exclude_folders, remove_include_path):

if 'command' in entry:

tokens = shlex.split(entry['command'])

elif 'arguments' in entry:

tokens = entry['arguments']

else:

return False

changed = False

sysroot = find_sysroot(tokens)

if sysroot is not None:

tokens = add_isystem_sysroot(tokens, sysroot)

tokens = remove_sysroot_arg(tokens)

changed = True

if isystem_to_i:

new_tokens = convert_isystem_to_i(tokens, exclude_folders)

if new_tokens != tokens:

tokens = new_tokens

changed = True

if remove_include_path:

new_tokens = remove_include_paths(tokens, remove_include_path)

if new_tokens != tokens:

tokens = new_tokens

changed = True

if not changed:

return False

if 'command' in entry:

entry['command'] = shlex.join(tokens)

else:

entry['arguments'] = tokens

return True

def main():

parser = argparse.ArgumentParser(

description='Add sysroot-relative -isystem arguments to build commands in a compile_commands.json file.')

parser.add_argument('compile_commands', help='path to the compile_commands.json file to read')

group = parser.add_mutually_exclusive_group()

group.add_argument('-o', '--output', help='write the result to this file instead of stdout')

group.add_argument('-i', '--in-place', action='store_true', help='overwrite the input file with the result')

parser.add_argument('--isystem-to-i', action='store_true',

help='convert -isystem arguments to -I (except excluded folders)')

parser.add_argument('--exclude-folder', action='append', default=[], metavar='FOLDER',

help='folder name to keep as -isystem when using --isystem-to-i; can be given multiple times')

parser.add_argument('--remove-include-path', action='append', default=[], metavar='PATH',

help='remove -I arguments whose path contains PATH; can be given multiple times')

args = parser.parse_args()

with open(args.compile_commands, encoding='utf-8') as f:

entries = json.load(f)

changed = 0

for entry in entries:

if tweak_entry(entry, args.isystem_to_i, args.exclude_folder, args.remove_include_path):

changed += 1

out = json.dumps(entries, indent=2) + '\n'

if args.in_place:

with open(args.compile_commands, 'w', encoding='utf-8') as f:

f.write(out)

elif args.output:

with open(args.output, 'w', encoding='utf-8') as f:

f.write(out)

else:

sys.stdout.write(out)

print('tweaked {} of {} entries'.format(changed, len(entries)), file=sys.stderr)

if __name__ == '__main__':

main()