#! /usr/bin/python3
# Copyright (C) 2019 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
#
# The GNU C Library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# The GNU C Library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with the GNU C Library; if not, see
# <http://www.gnu.org/licenses/>.
"""Verifies that installed headers do not use any obsolete constructs:
* legacy BSD typedefs superseded by <stdint.h>:
ushort uint ulong u_char u_short u_int u_long u_intNN_t quad_t u_quad_t
(sys/types.h is allowed to _define_ these types, but not to use them
to define anything else).
"""
import argparse
import collections
import re
import sys
# Simplified lexical analyzer for C preprocessing tokens.
# Does not implement trigraphs.
# Does not implement backslash-newline in the middle of any lexical
# item other than a string literal.
# Does not implement universal-character-names in identifiers.
# Treats prefixed strings (e.g. L"...") as two tokens (L and "...")
# Accepts non-ASCII characters only within comments and strings.
# Caution: The order of the outermost alternation matters.
# STRING must be before BAD_STRING, CHARCONST before BAD_CHARCONST,
# BLOCK_COMMENT before BAD_BLOCK_COM before PUNCTUATOR, and OTHER must
# be last.
# Caution: There should be no capturing groups other than the named
# captures in the outermost alternation.
# For reference, these are all of the C punctuators as of C11:
# [ ] ( ) { } , ; ? ~
# ! != * *= / /= ^ ^= = ==
# # ##
# % %= %> %: %:%:
# & &= &&
# | |= ||
# + += ++
# - -= -- ->
# . ...
# : :>
# < <% <: << <<= <=
# > >= >> >>=
# The BAD_* tokens are not part of the official definition of pp-tokens;
# they match unclosed strings, character constants, and block comments,
# so that the regex engine doesn't have to backtrack all the way to the
# beginning of a broken construct and then emit dozens of junk tokens.
PP_TOKEN_RE_ = re.compile(r"""
(?P<STRING> \"(?:[^\"\\\r\n]|\\(?:[\r\n -~]|\r\n))*\")
|(?P<BAD_STRING> \"(?:[^\"\\\r\n]|\\[ -~])*)
|(?P<CHARCONST> \'(?:[^\'\\\r\n]|\\(?:[\r\n -~]|\r\n))*\')
|(?P<BAD_CHARCONST> \'(?:[^\'\\\r\n]|\\[ -~])*)
|(?P<BLOCK_COMMENT> /\*(?:\*(?!/)|[^*])*\*/)
|(?P<BAD_BLOCK_COM> /\*(?:\*(?!/)|[^*])*\*?)
|(?P<LINE_COMMENT> //[^\r\n]*)
|(?P<IDENT> [_a-zA-Z][_a-zA-Z0-9]*)
|(?P<PP_NUMBER> \.?[0-9](?:[0-9a-df-oq-zA-DF-OQ-Z_.]|[eEpP][+-]?)*)
|(?P<PUNCTUATOR>
[,;?~(){}\[\]]
| [!*/^=]=?
| \#\#?
| %(?:[=>]|:(?:%:)?)?
| &[=&]?
|\|[=|]?
|\+[=+]?
| -[=->]?
|\.(?:\.\.)?
| :>?
| <(?:[%:]|<(?:=|<=?)?)?
| >(?:=|>=?)?)
|(?P<ESCNL> \\(?:\r|\n|\r\n))
|(?P<WHITESPACE> [ \t\n\r\v\f]+)
|(?P<OTHER> .)
""", re.DOTALL | re.VERBOSE)
HEADER_NAME_RE_ = re.compile(r"""
< [^>\r\n]+ >
| " [^"\r\n]+ "
""", re.DOTALL | re.VERBOSE)
ENDLINE_RE_ = re.compile(r"""\r|\n|\r\n""")
# based on the sample code in the Python re documentation
Token_ = collections.namedtuple("Token", (
"kind", "text", "line", "column", "context"))
Token_.__doc__ = """
One C preprocessing token, comment, or chunk of whitespace.
'kind' identifies the token type, which will be one of:
STRING, CHARCONST, BLOCK_COMMENT, LINE_COMMENT, IDENT,
PP_NUMBER, PUNCTUATOR, ESCNL, WHITESPACE, HEADER_NAME,
or OTHER. The BAD_* alternatives in PP_TOKEN_RE_ are
handled within tokenize_c, below.
'text' is the sequence of source characters making up the token;
no decoding whatsoever is performed.
'line' and 'column' give the position of the first character of the
token within the source file. They are both 1-based.
'context' indicates whether or not this token occurred within a
preprocessing directive; it will be None for running text,
'<null>' for the leading '#' of a directive line (because '#'
all by itself on a line is a "null directive"), or the name of
the directive for tokens within a directive line, starting with
the IDENT for the name itself.
"""
def tokenize_c(file_contents, reporter):
"""Yield a series of Token objects, one for each preprocessing
token, comment, or chunk of whitespace within FILE_CONTENTS.
The REPORTER object is expected to have one method,
reporter.error(token, message), which will be called to
indicate a lexical error at the position of TOKEN.
If MESSAGE contains the four-character sequence '{!r}', that
is expected to be replaced by repr(token.text).
"""
Token = Token_
PP_TOKEN_RE = PP_TOKEN_RE_
ENDLINE_RE = ENDLINE_RE_
HEADER_NAME_RE = HEADER_NAME_RE_
line_num = 1
line_start = 0
pos = 0
limit = len(file_contents)
directive = None
at_bol = True
while pos < limit:
if directive == "include":
mo = HEADER_NAME_RE.match(file_contents, pos)
if mo:
kind = "HEADER_NAME"
directive = "after_include"
else:
mo = PP_TOKEN_RE.match(file_contents, pos)
kind = mo.lastgroup
if kind != "WHITESPACE":
directive = "after_include"
else:
mo = PP_TOKEN_RE.match(file_contents, pos)
kind = mo.lastgroup
text = mo.group()
line = line_num
column = mo.start() - line_start
adj_line_start = 0
# only these kinds can contain a newline
if kind in ("WHITESPACE", "BLOCK_COMMENT", "LINE_COMMENT",
"STRING", "CHARCONST", "BAD_BLOCK_COM", "ESCNL"):
for tmo in ENDLINE_RE.finditer(text):
line_num += 1
adj_line_start = tmo.end()
if adj_line_start:
line_start = mo.start() + adj_line_start
# Track whether or not we are scanning a preprocessing directive.
if kind == "LINE_COMMENT" or (kind == "WHITESPACE" and adj_line_start):
at_bol = True
directive = None
else:
if kind == "PUNCTUATOR" and text == "#" and at_bol:
directive = "<null>"
elif kind == "IDENT" and directive == "<null>":
directive = text
at_bol = False
# Report ill-formed tokens and rewrite them as their well-formed
# equivalents, so downstream processing doesn't have to know about them.
# (Rewriting instead of discarding provides better error recovery.)
if kind == "BAD_BLOCK_COM":
reporter.error(Token("BAD_BLOCK_COM", "", line, column+1, ""),
"unclosed block comment")
text += "*/"
kind = "BLOCK_COMMENT"
elif kind == "BAD_STRING":
reporter.error(Token("BAD_STRING", "", line, column+1, ""),
"unclosed string")
text += "\""
kind = "STRING"
elif kind == "BAD_CHARCONST":
reporter.error(Token("BAD_CHARCONST", "", line, column+1, ""),
"unclosed char constant")
text += "'"
kind = "CHARCONST"
tok = Token(kind, text, line, column+1,
"include" if directive == "after_include" else directive)
# Do not complain about OTHER tokens inside macro definitions.
# $ and @ appear in macros defined by headers intended to be
# included from assembly language, e.g. sysdeps/mips/sys/asm.h.
if kind == "OTHER" and directive != "define":
self.error(tok, "stray {!r} in program")
yield tok
pos = mo.end()
#
# Base and generic classes for individual checks.
#
class ConstructChecker:
"""Scan a stream of C preprocessing tokens and possibly report
problems with them. The REPORTER object passed to __init__ has
one method, reporter.error(token, message), which should be
called to indicate a problem detected at the position of TOKEN.
If MESSAGE contains the four-character sequence '{!r}' then that
will be replaced with a textual representation of TOKEN.
"""
def __init__(self, reporter):
self.reporter = reporter
def examine(self, tok):
"""Called once for each token in a header file.
Call self.reporter.error if a problem is detected.
"""
raise NotImplementedError
def eof(self):
"""Called once at the end of the stream. Subclasses need only
override this if it might have something to do."""
pass
class NoCheck(ConstructChecker):
"""Generic checker class which doesn't do anything. Substitute this
class for a real checker when a particular check should be skipped
for some file."""
def examine(self, tok):
pass
#
# Check for obsolete type names.
#
# The obsolete type names we're looking for:
OBSOLETE_TYPE_RE_ = re.compile(r"""\A
(__)?
( quad_t
| u(?: short | int | long
| _(?: char | short | int(?:[0-9]+_t)? | long | quad_t )))
\Z""", re.VERBOSE)
class ObsoleteNotAllowed(ConstructChecker):
"""Don't allow any use of the obsolete typedefs."""
def examine(self, tok):
if OBSOLETE_TYPE_RE_.match(tok.text):
self.reporter.error(tok, "use of {!r}")
class ObsoletePrivateDefinitionsAllowed(ConstructChecker):
"""Allow definitions of the private versions of the
obsolete typedefs; that is, 'typedef [anything] __obsolete;'
"""
def __init__(self, reporter):
super().__init__(reporter)
self.in_typedef = False
self.prev_token = None
def examine(self, tok):
# bits/types.h hides 'typedef' in a macro sometimes.
if (tok.kind == "IDENT"
and tok.text in ("typedef", "__STD_TYPE")
and tok.context is None):
self.in_typedef = True
elif tok.kind == "PUNCTUATOR" and tok.text == ";" and self.in_typedef:
self.in_typedef = False
if self.prev_token.kind == "IDENT":
m = OBSOLETE_TYPE_RE_.match(self.prev_token.text)
if m and m.group(1) != "__":
self.reporter.error(self.prev_token, "use of {!r}")
self.prev_token = None
else:
self._check_prev()
self.prev_token = tok
def eof(self):
self._check_prev()
def _check_prev(self):
if (self.prev_token is not None
and self.prev_token.kind == "IDENT"
and OBSOLETE_TYPE_RE_.match(self.prev_token.text)):
self.reporter.error(self.prev_token, "use of {!r}")
class ObsoletePublicDefinitionsAllowed(ConstructChecker):
"""Allow definitions of the public versions of the obsolete
typedefs. Only specific forms of definition are allowed:
typedef __obsolete obsolete; // identifiers must agree
typedef __uintN_t u_intN_t; // N must agree
typedef unsigned long int ulong;
typedef unsigned short int ushort;
typedef unsigned int uint;
"""
def __init__(self, reporter):
super().__init__(reporter)
self.typedef_tokens = []
def examine(self, tok):
if tok.kind in ("WHITESPACE", "BLOCK_COMMENT",
"LINE_COMMENT", "NL", "ESCNL"):
pass
elif (tok.kind == "IDENT" and tok.text == "typedef"
and tok.context is None):
if self.typedef_tokens:
self.reporter.error(tok, "typedef inside typedef")
self._reset()
self.typedef_tokens.append(tok)
elif tok.kind == "PUNCTUATOR" and tok.text == ";":
self._finish()
elif self.typedef_tokens:
self.typedef_tokens.append(tok)
def eof(self):
self._reset()
def _reset(self):
while self.typedef_tokens:
tok = self.typedef_tokens.pop(0)
if tok.kind == "IDENT" and OBSOLETE_TYPE_RE_.match(tok.text):
self.reporter.error(tok, "use of {!r}")
def _finish(self):
if not self.typedef_tokens: return
if self.typedef_tokens[-1].kind == "IDENT":
m = OBSOLETE_TYPE_RE_.match(self.typedef_tokens[-1].text)
if m:
if self._permissible_public_definition(m):
self.typedef_tokens.clear()
self._reset()
def _permissible_public_definition(self, m):
if m.group(1) == "__": return False
name = m.group(2)
toks = self.typedef_tokens
ntok = len(toks)
if ntok == 3 and toks[1].kind == "IDENT":
defn = toks[1].text
n = OBSOLETE_TYPE_RE_.match(defn)
if n and n.group(1) == "__" and n.group(2) == name:
return True
if (name[:5] == "u_int" and name[-2:] == "_t"
and defn[:6] == "__uint" and defn[-2:] == "_t"
and name[5:-2] == defn[6:-2]):
return True
return False
if (name == "ulong" and ntok == 5
and toks[1].kind == "IDENT" and toks[1].text == "unsigned"
and toks[2].kind == "IDENT" and toks[2].text == "long"
and toks[3].kind == "IDENT" and toks[3].text == "int"):
return True
if (name == "ushort" and ntok == 5
and toks[1].kind == "IDENT" and toks[1].text == "unsigned"
and toks[2].kind == "IDENT" and toks[2].text == "short"
and toks[3].kind == "IDENT" and toks[3].text == "int"):
return True
if (name == "uint" and ntok == 4
and toks[1].kind == "IDENT" and toks[1].text == "unsigned"
and toks[2].kind == "IDENT" and toks[2].text == "int"):
return True
return False
def ObsoleteTypedefChecker(reporter, fname):
"""Factory: produce an instance of the appropriate
obsolete-typedef checker for FNAME."""
# The obsolete rpc/ and rpcsvc/ headers are allowed to use the
# obsolete types, because it would be more trouble than it's
# worth to remove them from headers that we intend to stop
# installing eventually anyway.
if (fname.startswith("rpc/")
or fname.startswith("rpcsvc/")
or "/rpc/" in fname
or "/rpcsvc/" in fname):
return NoCheck(reporter)
# bits/types.h is allowed to define the __-versions of the
# obsolete types.
if (fname == "bits/types.h"
or fname.endswith("/bits/types.h")):
return ObsoletePrivateDefinitionsAllowed(reporter)
# sys/types.h is allowed to use the __-versions of the
# obsolete types, but only to define the unprefixed versions.
if (fname == "sys/types.h"
or fname.endswith("/sys/types.h")):
return ObsoletePublicDefinitionsAllowed(reporter)
return ObsoleteNotAllowed(reporter)
#
# Master control
#
class HeaderChecker:
"""Perform all of the checks on each header. This is also the
"reporter" object expected by tokenize_c and ConstructChecker.
"""
def __init__(self):
self.fname = None
self.status = 0
def error(self, tok, message):
self.status = 1
if '{!r}' in message:
message = message.format(tok.text)
sys.stderr.write("{}:{}:{}: error: {}\n".format(
self.fname, tok.line, tok.column, message))
def check(self, fname):
self.fname = fname
try:
with open(fname, "rt") as fp:
contents = fp.read()
except OSError as e:
sys.stderr.write("{}: {}\n".format(fname, e.strerror))
self.status = 1
return
typedef_checker = ObsoleteTypedefChecker(self, self.fname)
for tok in tokenize_c(contents, self):
typedef_checker.examine(tok)
def main():
ap = argparse.ArgumentParser(description=__doc__)
ap.add_argument("headers", metavar="header", nargs="+",
help="one or more headers to scan for obsolete constructs")
args = ap.parse_args()
checker = HeaderChecker()
for fname in args.headers:
# Headers whose installed name begins with "finclude/" contain
# Fortran, not C, and this program should completely ignore them.
if not (fname.startswith("finclude/") or "/finclude/" in fname):
checker.check(fname)
sys.exit(checker.status)
main()