Python - Regexp -查找函数名称，但不查找函数调用

Question

好的，我有一堆C和C++代码，我需要过滤它们，找出函数定义。我不知道函数类型/返回值，也不知道函数定义或函数调用中的参数数量等。

到目前为止，我有：

import re, sys
from os.path import abspath
from os import walk

function = 'msg'
regexp = r"(" + function + ".*[^;]){"

found = False
for root, folders, files in walk('C:\\codepath\\'):
    for filename in files:
        with open(abspath(root + '/' + filename)) as fh:
            data = fh.read()
            result = re.findall(regexp, data)
            if len(result) > 0:
                sys.stdout.write('\n Found function "' + config.function + '" in ' + filename + ':\n\t' + str(result))
                sys.stdout.flush()
    break

然而，这会产生一些不想要的结果。regexp必须是these taulrant，例如以下组合：

找到"msg“的防御，但不是"msg()”调用，在所有的变体中说：

void
shapex_msg (struct shaper *s)
{
  msg (M_INFO, "Output Traffic Shaping initialized at %d bytes per second",
       s->bytes_per_second);
}

或

void shapex_msg (struct shaper *s)
{
  msg (M_INFO, "Output Traffic Shaping initialized at %d bytes per second",
       s->bytes_per_second);
}

或

void shapex_msg (struct shaper *s) {
  msg (M_INFO, "Output Traffic Shaping initialized at %d bytes per second",
       s->bytes_per_second);
}

Answer 1

可能类似于下面的正则表达式：

def make_regex(name):
    return re.compile(r'\s*%s\s*\([^;)]*\)\s*\{' % re.escape(name))

测试您的示例：

>>> text = '''
... void
... shapex_msg (struct shaper *s)
... {
...   msg (M_INFO, "Output Traffic Shaping initialized at %d bytes per second",
...        s->bytes_per_second);
... }
... 
... void shapex_msg (struct shaper *s)
... {
...   msg (M_INFO, "Output Traffic Shaping initialized at %d bytes per second",
...        s->bytes_per_second);
... }
... 
... void shapex_msg (struct shaper *s) {
...   msg (M_INFO, "Output Traffic Shaping initialized at %d bytes per second",
...        s->bytes_per_second);
... }'''
>>> shapex_msg = make_regex_for_function('shapex_msg')
>>> shapex_msg.findall(text)
['\nshapex_msg (struct shaper *s)\n{', ' shapex_msg (struct shaper *s)\n{', ' shapex_msg (struct shaper *s) {']

它仅适用于多行定义：

>>> shapex_msg.findall('''int
        shapex_msg      (
int a,
int b
)  

        {'''
['\n   \tshapex_msg   \t(\nint a,\nint b\n)  \n\n\t{']

而对于函数调用：

>>> shapex_msg.findall('shapex_msg(1,2,3);')
[]

需要注意的是，您的正则表达式无法工作，因为.*很贪婪，因此它没有匹配正确的右括号。