Function CheckEmptyBlockBody

tfjs-backend-wasm/tools/cpplint.py:4002–4103

Look for empty loop/conditional body with only a single semicolon. 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 CheckEmptyBlockBody(filename, clean_lines, linenum, error):
  """Look for empty loop/conditional body with only a single semicolon.

  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.
  """

  # Search for loop keywords at the beginning of the line.  Because only
  # whitespaces are allowed before the keywords, this will also ignore most
  # do-while-loops, since those lines should start with closing brace.
  #
  # We also check "if" blocks here, since an empty conditional block
  # is likely an error.
  line = clean_lines.elided[linenum]
  matched = Match(r'\s*(for|while|if)\s*\(', line)
  if matched:
    # Find the end of the conditional expression.
    (end_line, end_linenum, end_pos) = CloseExpression(
        clean_lines, linenum, line.find('('))

    # Output warning if what follows the condition expression is a semicolon.
    # No warning for all other cases, including whitespace or newline, since we
    # have a separate check for semicolons preceded by whitespace.
    if end_pos >= 0 and Match(r';', end_line[end_pos:]):
      if matched.group(1) == 'if':
        error(filename, end_linenum, 'whitespace/empty_conditional_body', 5,
              'Empty conditional bodies should use {}')
      else:
        error(filename, end_linenum, 'whitespace/empty_loop_body', 5,
              'Empty loop bodies should use {} or continue')

    # Check for if statements that have completely empty bodies (no comments)
    # and no else clauses.
    if end_pos >= 0 and matched.group(1) == 'if':
      # Find the position of the opening { for the if statement.
      # Return without logging an error if it has no brackets.
      opening_linenum = end_linenum
      opening_line_fragment = end_line[end_pos:]
      # Loop until EOF or find anything that's not whitespace or opening {.
      while not Search(r'^\s*\{', opening_line_fragment):
        if Search(r'^(?!\s*$)', opening_line_fragment):
          # Conditional has no brackets.
          return
        opening_linenum += 1
        if opening_linenum == len(clean_lines.elided):
          # Couldn't find conditional's opening { or any code before EOF.
          return
        opening_line_fragment = clean_lines.elided[opening_linenum]
      # Set opening_line (opening_line_fragment may not be entire opening line).
      opening_line = clean_lines.elided[opening_linenum]

      # Find the position of the closing }.
      opening_pos = opening_line_fragment.find('{')
      if opening_linenum == end_linenum:
        # We need to make opening_pos relative to the start of the entire line.