parameters: (filename, clean_lines, linenum,
                                    nesting_state, error)
docstring: r"""Logs an error if we see certain non-ANSI constructs ignored by gcc-2.
  
    Complain about several constructs which gcc-2 accepts, but which are
    not standard C++.  Warning about these in lint is one way to ease the
    transition to new compilers.
    - put storage class first (e.g. "static const" instead of "const static").
    - "%lld" instead of %qd" in printf-type functions.
    - "%1$d" is non-standard in printf-type functions.
    - "\%" is an undefined character escape sequence.
    - text after #endif is not allowed.
    - invalid inner-style forward declaration.
    - >? and <? operators, and their >?= and <?= cousins.
  
    Additionally, check for constructor/destructor style violations and reference
    members, as it is very convenient to do so while checking for
    gcc-2 compliance.
  
    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: A callable to which errors are reported, which takes 4 arguments:
             filename, line number, error level, and message
docstring_summary: r"""Logs an error if we see certain non-ANSI constructs ignored by gcc-2.
docstring_tokens: r Logs an error if we see certain non - ANSI constructs ignored by gcc - 2 .
function: def CheckForNonStandardConstructs(filename, clean_lines, linenum,
                                    nesting_state, error):
    r"""Logs an error if we see certain non-ANSI constructs ignored by gcc-2.
  
    Complain about several constructs which gcc-2 accepts, but which are
    not standard C++.  Warning about these in lint is one way to ease the
    transition to new compilers.
    - put storage class first (e.g. "static const" instead of "const static").
    - "%lld" instead of %qd" in printf-type functions.
    - "%1$d" is non-standard in printf-type functions.
    - "\%" is an undefined character escape sequence.
    - text after #endif is not allowed.
    - invalid inner-style forward declaration.
    - >? and <? operators, and their >?= and <?= cousins.
  
    Additionally, check for constructor/destructor style violations and reference
    members, as it is very convenient to do so while checking for
    gcc-2 compliance.
  
    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: A callable to which errors are reported, which takes 4 arguments:
             filename, line number, error level, and message
    """
  
    # Remove comments from the line, but leave in strings for now.
    line = clean_lines.lines[linenum]
  
    if Search(r'printf\s*\(.*".*%[-+ ]?\d*q', line):
      error(filename, linenum, 'runtime/printf_format', 3,
            '%q in format strings is deprecated.  Use %ll instead.')
  
    if Search(r'printf\s*\(.*".*%\d+\$', line):
      error(filename, linenum, 'runtime/printf_format', 2,
            '%N$ formats are unconventional.  Try rewriting to avoid them.')
  
    # Remove escaped backslashes before looking for undefined escapes.
    line = line.replace('\\\\', '')
  
    if Search(r'("|\').*\\(%|\[|\(|{)', line):
      error(filename, linenum, 'build/printf_format', 3,
            '%, [, (, and { are undefined character escapes.  Unescape them.')
  
    # For the rest, work with both comments and strings removed.
    line = clean_lines.elided[linenum]
  
    if Search(r'\b(const|volatile|void|char|short|int|long'
              r'|float|double|signed|unsigned'
              r'|schar|u?int8|u?int16|u?int32|u?int64)'
              r'\s+(register|static|extern|typedef)\b',
              line):
      error(filename, linenum, 'build/storage_class', 5,
            'Storage-class specifier (static, extern, typedef, etc) should be '
            'at the beginning of the declaration.')
  
    if Match(r'\s*#\s*endif\s*[^/\s]+', line):
      error(filename, linenum, 'build/endif_comment', 5,
            'Uncommented text after #endif is non-standard.  Use a comment.')
  
    if Match(r'\s*class\s+(\w+\s*::\s*)+\w+\s*;', line):
      error(filename, linenum, 'build/forward_decl', 5,
            'Inner-style forward declarations are invalid.  Remove this line.')
  
    if Search(r'(\w+|[+-]?\d+(\.\d*)?)\s*(<|>)\?=?\s*(\w+|[+-]?\d+)(\.\d*)?',
              line):
      error(filename, linenum, 'build/deprecated', 3,
            '>? and <? (max and min) operators are non-standard and deprecated.')
  
    if Search(r'^\s*const\s*string\s*&\s*\w+\s*;', line):
      # TODO(unknown): Could it be expanded safely to arbitrary references,
      # without triggering too many false positives? The first
      # attempt triggered 5 warnings for mostly benign code in the regtest, hence
      # the restriction.
      # Here's the original regexp, for the reference:
      # type_name = r'\w+((\s*::\s*\w+)|(\s*<\s*\w+?\s*>))?'
      # r'\s*const\s*' + type_name + '\s*&\s*\w+\s*;'
      error(filename, linenum, 'runtime/member_string_references', 2,
            'const string& members are dangerous. It is much better to use '
            'alternatives, such as pointers or simple constants.')
  
    # Everything else in this function operates on class declarations.
    # Return early if the top of the nesting stack is not a class, or if
    # the class head is not completed yet.
    classinfo = nesting_state.InnermostClass()
    if not classinfo or not classinfo.seen_open_brace:
      return
  
    # The class may have been declared with namespace or classname qualifiers.
    # The constructor and destructor will not have those qualifiers.
    base_classname = classinfo.name.split('::')[-1]
  
    # Look for single-argument constructors that aren't marked explicit.
    # Technically a valid construct, but against style.
    explicit_constructor_match = Match(
        r'\s+(?:(?:inline|constexpr)\s+)*(explicit\s+)?'
        r'(?:(?:inline|constexpr)\s+)*%s\s*'
        r'\(((?:[^()]|\([^()]*\))*)\)'
        % re.escape(base_classname),
        line)
  
    if explicit_constructor_match:
      is_marked_explicit = explicit_constructor_match.group(1)
  
      if not explicit_constructor_match.group(2):
        constructor_args = []
      else:
        constructor_args = explicit_constructor_match.group(2).split(',')
  
      # collapse arguments so that commas in template parameter lists and function
      # argument parameter lists don't split arguments in two
      i = 0
      while i < len(constructor_args):
        constructor_arg = constructor_args[i]
        while (constructor_arg.count('<') > constructor_arg.count('>') or
               constructor_arg.count('(') > constructor_arg.count(')')):
          constructor_arg += ',' + constructor_args[i + 1]
          del constructor_args[i + 1]
        constructor_args[i] = constructor_arg
        i += 1
  
      variadic_args = [arg for arg in constructor_args if '&&...' in arg]
      defaulted_args = [arg for arg in constructor_args if '=' in arg]
      noarg_constructor = (not constructor_args or  # empty arg list
                           # 'void' arg specifier
                           (len(constructor_args) == 1 and
                            constructor_args[0].strip() == 'void'))
      onearg_constructor = ((len(constructor_args) == 1 and  # exactly one arg
                             not noarg_constructor) or
                            # all but at most one arg defaulted
                            (len(constructor_args) >= 1 and
                             not noarg_constructor and
                             len(defaulted_args) >= len(constructor_args) - 1) or
                            # variadic arguments with zero or one argument
                            (len(constructor_args) <= 2 and
                             len(variadic_args) >= 1))
      initializer_list_constructor = bool(
          onearg_constructor and
          Search(r'\bstd\s*::\s*initializer_list\b', constructor_args[0]))
      copy_constructor = bool(
          onearg_constructor and
          Match(r'((const\s+(volatile\s+)?)?|(volatile\s+(const\s+)?))?'
                r'%s(\s*<[^>]*>)?(\s+const)?\s*(?:<\w+>\s*)?&'
                % re.escape(base_classname), constructor_args[0].strip()))
  
      if (not is_marked_explicit and
          onearg_constructor and
          not initializer_list_constructor and
          not copy_constructor):
        if defaulted_args or variadic_args:
          error(filename, linenum, 'runtime/explicit', 5,
                'Constructors callable with one argument '
                'should be marked explicit.')
        else:
          error(filename, linenum, 'runtime/explicit', 5,
                'Single-parameter constructors should be marked explicit.')
      elif is_marked_explicit and not onearg_constructor:
        if noarg_constructor:
          error(filename, linenum, 'runtime/explicit', 5,
                'Zero-parameter constructors should not be marked explicit.')
function_tokens: def CheckForNonStandardConstructs ( filename , clean_lines , linenum , nesting_state , error ) : # Remove comments from the line, but leave in strings for now. line = clean_lines . lines [ linenum ] if Search ( r'printf\s*\(.*".*%[-+ ]?\d*q' , line ) : error ( filename , linenum , 'runtime/printf_format' , 3 , '%q in format strings is deprecated.  Use %ll instead.' ) if Search ( r'printf\s*\(.*".*%\d+\$' , line ) : error ( filename , linenum , 'runtime/printf_format' , 2 , '%N$ formats are unconventional.  Try rewriting to avoid them.' ) # Remove escaped backslashes before looking for undefined escapes. line = line . replace ( '\\\\' , '' ) if Search ( r'("|\').*\\(%|\[|\(|{)' , line ) : error ( filename , linenum , 'build/printf_format' , 3 , '%, [, (, and { are undefined character escapes.  Unescape them.' ) # For the rest, work with both comments and strings removed. line = clean_lines . elided [ linenum ] if Search ( r'\b(const|volatile|void|char|short|int|long' r'|float|double|signed|unsigned' r'|schar|u?int8|u?int16|u?int32|u?int64)' r'\s+(register|static|extern|typedef)\b' , line ) : error ( filename , linenum , 'build/storage_class' , 5 , 'Storage-class specifier (static, extern, typedef, etc) should be ' 'at the beginning of the declaration.' ) if Match ( r'\s*#\s*endif\s*[^/\s]+' , line ) : error ( filename , linenum , 'build/endif_comment' , 5 , 'Uncommented text after #endif is non-standard.  Use a comment.' ) if Match ( r'\s*class\s+(\w+\s*::\s*)+\w+\s*;' , line ) : error ( filename , linenum , 'build/forward_decl' , 5 , 'Inner-style forward declarations are invalid.  Remove this line.' ) if Search ( r'(\w+|[+-]?\d+(\.\d*)?)\s*(<|>)\?=?\s*(\w+|[+-]?\d+)(\.\d*)?' , line ) : error ( filename , linenum , 'build/deprecated' , 3 , '>? and <? (max and min) operators are non-standard and deprecated.' ) if Search ( r'^\s*const\s*string\s*&\s*\w+\s*;' , line ) : # TODO(unknown): Could it be expanded safely to arbitrary references, # without triggering too many false positives? The first # attempt triggered 5 warnings for mostly benign code in the regtest, hence # the restriction. # Here's the original regexp, for the reference: # type_name = r'\w+((\s*::\s*\w+)|(\s*<\s*\w+?\s*>))?' # r'\s*const\s*' + type_name + '\s*&\s*\w+\s*;' error ( filename , linenum , 'runtime/member_string_references' , 2 , 'const string& members are dangerous. It is much better to use ' 'alternatives, such as pointers or simple constants.' ) # Everything else in this function operates on class declarations. # Return early if the top of the nesting stack is not a class, or if # the class head is not completed yet. classinfo = nesting_state . InnermostClass ( ) if not classinfo or not classinfo . seen_open_brace : return # The class may have been declared with namespace or classname qualifiers. # The constructor and destructor will not have those qualifiers. base_classname = classinfo . name . split ( '::' ) [ - 1 ] # Look for single-argument constructors that aren't marked explicit. # Technically a valid construct, but against style. explicit_constructor_match = Match ( r'\s+(?:(?:inline|constexpr)\s+)*(explicit\s+)?' r'(?:(?:inline|constexpr)\s+)*%s\s*' r'\(((?:[^()]|\([^()]*\))*)\)' % re . escape ( base_classname ) , line ) if explicit_constructor_match : is_marked_explicit = explicit_constructor_match . group ( 1 ) if not explicit_constructor_match . group ( 2 ) : constructor_args = [ ] else : constructor_args = explicit_constructor_match . group ( 2 ) . split ( ',' ) # collapse arguments so that commas in template parameter lists and function # argument parameter lists don't split arguments in two i = 0 while i < len ( constructor_args ) : constructor_arg = constructor_args [ i ] while ( constructor_arg . count ( '<' ) > constructor_arg . count ( '>' ) or constructor_arg . count ( '(' ) > constructor_arg . count ( ')' ) ) : constructor_arg += ',' + constructor_args [ i + 1 ] del constructor_args [ i + 1 ] constructor_args [ i ] = constructor_arg i += 1 variadic_args = [ arg for arg in constructor_args if '&&...' in arg ] defaulted_args = [ arg for arg in constructor_args if '=' in arg ] noarg_constructor = ( not constructor_args or # empty arg list # 'void' arg specifier ( len ( constructor_args ) == 1 and constructor_args [ 0 ] . strip ( ) == 'void' ) ) onearg_constructor = ( ( len ( constructor_args ) == 1 and # exactly one arg not noarg_constructor ) or # all but at most one arg defaulted ( len ( constructor_args ) >= 1 and not noarg_constructor and len ( defaulted_args ) >= len ( constructor_args ) - 1 ) or # variadic arguments with zero or one argument ( len ( constructor_args ) <= 2 and len ( variadic_args ) >= 1 ) ) initializer_list_constructor = bool ( onearg_constructor and Search ( r'\bstd\s*::\s*initializer_list\b' , constructor_args [ 0 ] ) ) copy_constructor = bool ( onearg_constructor and Match ( r'((const\s+(volatile\s+)?)?|(volatile\s+(const\s+)?))?' r'%s(\s*<[^>]*>)?(\s+const)?\s*(?:<\w+>\s*)?&' % re . escape ( base_classname ) , constructor_args [ 0 ] . strip ( ) ) ) if ( not is_marked_explicit and onearg_constructor and not initializer_list_constructor and not copy_constructor ) : if defaulted_args or variadic_args : error ( filename , linenum , 'runtime/explicit' , 5 , 'Constructors callable with one argument ' 'should be marked explicit.' ) else : error ( filename , linenum , 'runtime/explicit' , 5 , 'Single-parameter constructors should be marked explicit.' ) elif is_marked_explicit and not onearg_constructor : if noarg_constructor : error ( filename , linenum , 'runtime/explicit' , 5 , 'Zero-parameter constructors should not be marked explicit.' )