Function CheckCasts

tools/cpplint.py:6601–6751

Various cast related checks. Args: filename: The name of the current file. clean_lines: A CleansedLines instance containing the file. linenum: The number of the line to check. error: The function to call with any errors found.

(filename, clean_lines, linenum, error)

def CheckCasts(filename, clean_lines, linenum, error):
    """Various cast related checks.

    Args:
      filename: The name of the current file.
      clean_lines: A CleansedLines instance containing the file.
      linenum: The number of the line to check.
      error: The function to call with any errors found.
    """
    line = clean_lines.elided[linenum]

    # Check to see if they're using an conversion function cast.
    # I just try to capture the most common basic types, though there are more.
    # Parameterless conversion functions, such as bool(), are allowed as they are
    # probably a member operator declaration or default constructor.
    match = re.search(
        r"(\bnew\s+(?:const\s+)?|\S<\s*(?:const\s+)?)?\b"
        r"(int|float|double|bool|char|int16_t|uint16_t|int32_t|uint32_t|int64_t|uint64_t)"
        r"(\([^)].*)",
        line,
    )
    expecting_function = ExpectingFunctionArgs(clean_lines, linenum)
    if match and not expecting_function:
        matched_type = match.group(2)

        # matched_new_or_template is used to silence two false positives:
        # - New operators
        # - Template arguments with function types
        #
        # For template arguments, we match on types immediately following
        # an opening bracket without any spaces.  This is a fast way to
        # silence the common case where the function type is the first
        # template argument.  False negative with less-than comparison is
        # avoided because those operators are usually followed by a space.
        #
        #   function<double(double)>   // bracket + no space = false positive
        #   value < double(42)         // bracket + space = true positive
        matched_new_or_template = match.group(1)

        # Avoid arrays by looking for brackets that come after the closing
        # parenthesis.
        if re.match(r"\([^()]+\)\s*\[", match.group(3)):
            return

        # Other things to ignore:
        # - Function pointers
        # - Casts to pointer types
        # - Placement new
        # - Alias declarations
        matched_funcptr = match.group(3)
        if (
            matched_new_or_template is None
            and not (
                matched_funcptr
                and (
                    re.match(r"\((?:[^() ]+::\s*\*\s*)?[^() ]+\)\s*\(", matched_funcptr)
                    or matched_funcptr.startswith("(*)")
                )