Function CheckSpacing

tools/cpplint.py:4213–4348

Checks for the correctness of various spacing issues in the code. Things we check for: spaces around operators, spaces after if/for/while/switch, no spaces around parens in function calls, two spaces between code and comment, don't start a block with a blank line, don't end a functi

(filename, clean_lines, linenum, nesting_state, error)

def CheckSpacing(filename, clean_lines, linenum, nesting_state, error):
    """Checks for the correctness of various spacing issues in the code.

    Things we check for: spaces around operators, spaces after
    if/for/while/switch, no spaces around parens in function calls, two
    spaces between code and comment, don't start a block with a blank
    line, don't end a function with a blank line, don't add a blank line
    after public/protected/private, don't have too many blank lines in a row.

    Args:
      filename: The name of the current file.
      clean_lines: A CleansedLines instance containing the file.
      linenum: The number of the line to check.
      nesting_state: A NestingState instance which maintains information about
                     the current stack of nested blocks being parsed.
      error: The function to call with any errors found.
    """

    # Don't use "elided" lines here, otherwise we can't check commented lines.
    # Don't want to use "raw" either, because we don't want to check inside C++11
    # raw strings,
    raw = clean_lines.lines_without_raw_strings
    line = raw[linenum]

    # Before nixing comments, check if the line is blank for no good
    # reason.  This includes the first line after a block is opened, and
    # blank lines at the end of a function (ie, right before a line like '}'
    #
    # Skip all the blank line checks if we are immediately inside a
    # namespace body.  In other words, don't issue blank line warnings
    # for this block:
    #   namespace {
    #
    #   }
    #
    # A warning about missing end of namespace comments will be issued instead.
    #
    # Also skip blank line checks for 'extern "C"' blocks, which are formatted
    # like namespaces.
    if IsBlankLine(line) and not nesting_state.InNamespaceBody() and not nesting_state.InExternC():
        elided = clean_lines.elided
        prev_line = elided[linenum - 1]
        prevbrace = prev_line.rfind("{")
        # TODO(google): Don't complain if line before blank line, and line after,
        #                both start with alnums and are indented the same amount.
        #                This ignores whitespace at the start of a namespace block
        #                because those are not usually indented.
        if prevbrace != -1 and prev_line[prevbrace:].find("}") == -1:
            # OK, we have a blank line at the start of a code block.  Before we
            # complain, we check if it is an exception to the rule: The previous
            # non-empty line has the parameters of a function header that are indented
            # 4 spaces (because they did not fit in a 80 column line when placed on
            # the same line as the function name).  We also check for the case where
            # the previous line is indented 6 spaces, which may happen when the
            # initializers of a constructor do not fit into a 80 column line.
            exception = False
            if re.match(r" {6}\w", prev_line):  # Initializer list?
                # We are looking for the opening column of initializer list, which