in cpplint.py [0:0]
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.
opening_pos += end_pos
(closing_line, closing_linenum, closing_pos) = CloseExpression(
clean_lines, opening_linenum, opening_pos)
if closing_pos < 0:
return
# Now construct the body of the conditional. This consists of the portion
# of the opening line after the {, all lines until the closing line,
# and the portion of the closing line before the }.
if (clean_lines.raw_lines[opening_linenum] !=
CleanseComments(clean_lines.raw_lines[opening_linenum])):
# Opening line ends with a comment, so conditional isn't empty.
return
if closing_linenum > opening_linenum:
# Opening line after the {. Ignore comments here since we checked above.
body = list(opening_line[opening_pos + 1:])
# All lines until closing line, excluding closing line, with comments.
body.extend(clean_lines.raw_lines[opening_linenum + 1:closing_linenum])
# Closing line before the }. Won't (and can't) have comments.
body.append(clean_lines.elided[closing_linenum][:closing_pos - 1])
body = '\n'.join(body)
else:
# If statement has brackets and fits on a single line.
body = opening_line[opening_pos + 1:closing_pos - 1]
# Check if the body is empty
if not _EMPTY_CONDITIONAL_BODY_PATTERN.search(body):
return
# The body is empty. Now make sure there's not an else clause.
current_linenum = closing_linenum
current_line_fragment = closing_line[closing_pos:]
# Loop until EOF or find anything that's not whitespace or else clause.
while Search(r'^\s*$|^(?=\s*else)', current_line_fragment):
if Search(r'^(?=\s*else)', current_line_fragment):
# Found an else clause, so don't log an error.
return
current_linenum += 1
if current_linenum == len(clean_lines.elided):
break
current_line_fragment = clean_lines.elided[current_linenum]
# The body is empty and there's no else clause until EOF or other code.
error(filename, end_linenum, 'whitespace/empty_if_body', 4,
('If statement had no body and no else clause'))