in cpp/misc/cpplint.py [0:0]
def CheckOperatorSpacing(filename, clean_lines, linenum, error):
"""Checks for horizontal spacing around operators.
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]
# Don't try to do spacing checks for operator methods. Do this by
# replacing the troublesome characters with something else,
# preserving column position for all other characters.
#
# The replacement is done repeatedly to avoid false positives from
# operators that call operators.
while True:
match = Match(r'^(.*\boperator\b)(\S+)(\s*\(.*)$', line)
if match:
line = match.group(1) + ('_' * len(match.group(2))) + match.group(3)
else:
break
# We allow no-spaces around = within an if: "if ( (a=Foo()) == 0 )".
# Otherwise not. Note we only check for non-spaces on *both* sides;
# sometimes people put non-spaces on one side when aligning ='s among
# many lines (not that this is behavior that I approve of...)
if ((Search(r'[\w.]=', line) or
Search(r'=[\w.]', line))
and not Search(r'\b(if|while|for) ', line)
# Operators taken from [lex.operators] in C++11 standard.
and not Search(r'(>=|<=|==|!=|&=|\^=|\|=|\+=|\*=|\/=|\%=)', line)
and not Search(r'operator=', line)):
error(filename, linenum, 'whitespace/operators', 4,
'Missing spaces around =')
# It's ok not to have spaces around binary operators like + - * /, but if
# there's too little whitespace, we get concerned. It's hard to tell,
# though, so we punt on this one for now. TODO.
# You should always have whitespace around binary operators.
#
# Check <= and >= first to avoid false positives with < and >, then
# check non-include lines for spacing around < and >.
#
# If the operator is followed by a comma, assume it's be used in a
# macro context and don't do any checks. This avoids false
# positives.
#
# Note that && is not included here. This is because there are too
# many false positives due to RValue references.
match = Search(r'[^<>=!\s](==|!=|<=|>=|\|\|)[^<>=!\s,;\)]', line)
if match:
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around %s' % match.group(1))
elif not Match(r'#.*include', line):
# Look for < that is not surrounded by spaces. This is only
# triggered if both sides are missing spaces, even though
# technically should should flag if at least one side is missing a
# space. This is done to avoid some false positives with shifts.
match = Match(r'^(.*[^\s<])<[^\s=<,]', line)
if match:
(_, _, end_pos) = CloseExpression(
clean_lines, linenum, len(match.group(1)))
if end_pos <= -1:
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around <')
# Look for > that is not surrounded by spaces. Similar to the
# above, we only trigger if both sides are missing spaces to avoid
# false positives with shifts.
match = Match(r'^(.*[^-\s>])>[^\s=>,]', line)
if match:
(_, _, start_pos) = ReverseCloseExpression(
clean_lines, linenum, len(match.group(1)))
if start_pos <= -1:
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around >')
# We allow no-spaces around << when used like this: 10<<20, but
# not otherwise (particularly, not when used as streams)
#
# We also allow operators following an opening parenthesis, since
# those tend to be macros that deal with operators.
match = Search(r'(operator|[^\s(<])(?:L|UL|LL|ULL|l|ul|ll|ull)?<<([^\s,=<])', line)
if (match and not (match.group(1).isdigit() and match.group(2).isdigit()) and
not (match.group(1) == 'operator' and match.group(2) == ';')):
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around <<')
# We allow no-spaces around >> for almost anything. This is because
# C++11 allows ">>" to close nested templates, which accounts for
# most cases when ">>" is not followed by a space.
#
# We still warn on ">>" followed by alpha character, because that is
# likely due to ">>" being used for right shifts, e.g.:
# value >> alpha
#
# When ">>" is used to close templates, the alphanumeric letter that
# follows would be part of an identifier, and there should still be
# a space separating the template type and the identifier.
# type<type<type>> alpha
match = Search(r'>>[a-zA-Z_]', line)
if match:
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around >>')
# There shouldn't be space around unary operators
match = Search(r'(!\s|~\s|[\s]--[\s;]|[\s]\+\+[\s;])', line)
if match:
error(filename, linenum, 'whitespace/operators', 4,
'Extra space for operator %s' % match.group(1))