Package: emacs;
Reported by: Paul Eggert <eggert <at> cs.ucla.edu>
Date: Mon, 16 May 2011 05:08:02 UTC
Severity: normal
Done: Paul Eggert <eggert <at> cs.ucla.edu>
Bug is archived. No further changes may be made.
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From: help-debbugs <at> gnu.org (GNU bug Tracking System) To: Paul Eggert <eggert <at> cs.ucla.edu> Cc: tracker <at> debbugs.gnu.org Subject: bug#8675: closed (lisp_string_width and strings wider than INT_MAX) Date: Wed, 18 May 2011 01:34:02 +0000
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Your message dated Tue, 17 May 2011 18:33:25 -0700 with message-id <4DD321E5.2020202 <at> cs.ucla.edu> and subject line committed fix into trunk has caused the GNU bug report #8675, regarding lisp_string_width and strings wider than INT_MAX to be marked as done. (If you believe you have received this mail in error, please contact help-debbugs <at> gnu.org.) -- 8675: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=8675 GNU Bug Tracking System Contact help-debbugs <at> gnu.org with problems
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From: Paul Eggert <eggert <at> cs.ucla.edu> To: bug-gnu-emacs <at> gnu.org Subject: lisp_string_width and strings wider than INT_MAX Date: Sun, 15 May 2011 22:07:36 -0700lisp_string_width requires that the precision be less than INT_MAX, and if no precision is given, misbehaves badly when dealing with strings whose widths are greater than INT_MAX. To address this, I plan to install the following patch (PATCH 3) after some more testing. PATCH 3 depends on two obvious patches: PATCH 2 introduces a helper no-return function string_overflow, and PATCH 1 updates to the latest version of gnulib. One thing about PATCH 3: when used in Emacs, the new lisp_string_width correctly signals an overflow when the string's width cannot be represented, but when used outside Emacs (in mulelib) it silently ignores the problem, just as before. I don't know much about mulelib and so don't know how to address this. But anyway, mulelib uses should be no worse off than before. PATCH 3 --------------------------------------------------- === modified file 'src/ChangeLog' --- src/ChangeLog 2011-05-16 01:11:54 +0000 +++ src/ChangeLog 2011-05-16 01:25:38 +0000 @@ -1,5 +1,14 @@ 2011-05-16 Paul Eggert <eggert <at> cs.ucla.edu> + * character.c (lisp_string_width): Check for string overflow. + Use EMACS_INT, not int, for string indexes and lengths; in + particular, 2nd arg is now EMACS_INT, not int. Do not crash if + the resulting string length overflows an EMACS_INT; instead, + report a string overflow if no precision given. When checking for + precision exhaustion, use a check that cannot possibly have + integer overflow. + * character.h (lisp_string_width): Adjust to new signature. + * alloc.c (string_overflow): New function. (Fmake_string): Use it. This doesn't change behavior, but saves a few bytes and will simplify future changes. === modified file 'src/character.c' --- src/character.c 2011-05-16 01:11:54 +0000 +++ src/character.c 2011-05-16 01:17:19 +0000 @@ -35,6 +35,7 @@ #include <sys/types.h> #include <setjmp.h> +#include <intprops.h> #include "lisp.h" #include "character.h" #include "buffer.h" @@ -404,7 +405,7 @@ in *NCHARS and *NBYTES respectively. */ EMACS_INT -lisp_string_width (Lisp_Object string, int precision, +lisp_string_width (Lisp_Object string, EMACS_INT precision, EMACS_INT *nchars, EMACS_INT *nbytes) { EMACS_INT len = SCHARS (string); @@ -419,7 +420,7 @@ while (i < len) { - int chars, bytes, thiswidth; + EMACS_INT chars, bytes, thiswidth; Lisp_Object val; int cmp_id; EMACS_INT ignore, end; @@ -437,7 +438,11 @@ int c; if (multibyte) - c = STRING_CHAR_AND_LENGTH (str + i_byte, bytes); + { + int cbytes; + c = STRING_CHAR_AND_LENGTH (str + i_byte, cbytes); + bytes = cbytes; + } else c = str[i_byte], bytes = 1; chars = 1; @@ -455,8 +460,14 @@ } } - if (precision > 0 - && (width + thiswidth > precision)) + if (precision <= 0) + { +#ifdef emacs + if (INT_ADD_OVERFLOW (width, thiswidth)) + string_overflow (); +#endif + } + else if (precision - width < thiswidth) { *nchars = i; *nbytes = i_byte; === modified file 'src/character.h' --- src/character.h 2011-04-11 03:39:45 +0000 +++ src/character.h 2011-05-16 01:13:28 +0000 @@ -612,7 +612,7 @@ extern EMACS_INT strwidth (const char *, EMACS_INT); extern EMACS_INT c_string_width (const unsigned char *, EMACS_INT, int, EMACS_INT *, EMACS_INT *); -extern EMACS_INT lisp_string_width (Lisp_Object, int, +extern EMACS_INT lisp_string_width (Lisp_Object, EMACS_INT, EMACS_INT *, EMACS_INT *); extern Lisp_Object Qcharacterp; PATCH 2 --------------------------------------------------- === modified file 'src/ChangeLog' --- src/ChangeLog 2011-05-15 17:17:44 +0000 +++ src/ChangeLog 2011-05-16 01:11:54 +0000 @@ -1,3 +1,11 @@ +2011-05-16 Paul Eggert <eggert <at> cs.ucla.edu> + + * alloc.c (string_overflow): New function. + (Fmake_string): Use it. This doesn't change behavior, but saves + a few bytes and will simplify future changes. + * character.c (string_escape_byte8): Likewise. + * lisp.h (string_overflow): New decl. + 2011-05-15 Paul Eggert <eggert <at> cs.ucla.edu> Fixups, following up to the user-interface timestamp change. === modified file 'src/alloc.c' --- src/alloc.c 2011-05-12 07:07:06 +0000 +++ src/alloc.c 2011-05-16 01:11:54 +0000 @@ -2174,6 +2174,11 @@ current_sblock = tb; } +void +string_overflow (void) +{ + error ("Maximum string size exceeded"); +} DEFUN ("make-string", Fmake_string, Smake_string, 2, 2, 0, doc: /* Return a newly created string of length LENGTH, with INIT in each element. @@ -2206,7 +2211,7 @@ EMACS_INT string_len = XINT (length); if (string_len > MOST_POSITIVE_FIXNUM / len) - error ("Maximum string size exceeded"); + string_overflow (); nbytes = len * string_len; val = make_uninit_multibyte_string (string_len, nbytes); p = SDATA (val); === modified file 'src/character.c' --- src/character.c 2011-05-12 07:07:06 +0000 +++ src/character.c 2011-05-16 01:11:54 +0000 @@ -823,7 +823,7 @@ { if ((MOST_POSITIVE_FIXNUM - nchars) / 3 < byte8_count || (MOST_POSITIVE_FIXNUM - nbytes) / 2 < byte8_count) - error ("Maximum string size exceeded"); + string_overflow (); /* Convert 2-byte sequence of byte8 chars to 4-byte octal. */ val = make_uninit_multibyte_string (nchars + byte8_count * 3, @@ -832,7 +832,7 @@ else { if ((MOST_POSITIVE_FIXNUM - nchars) / 3 < byte8_count) - error ("Maximum string size exceeded"); + string_overflow (); /* Convert 1-byte sequence of byte8 chars to 4-byte octal. */ val = make_uninit_string (nbytes + byte8_count * 3); } === modified file 'src/lisp.h' --- src/lisp.h 2011-05-15 17:17:44 +0000 +++ src/lisp.h 2011-05-16 01:11:54 +0000 @@ -2710,6 +2710,7 @@ EXFUN (Fvector, MANY); EXFUN (Fmake_symbol, 1); EXFUN (Fmake_marker, 0); +extern void string_overflow (void) NO_RETURN; EXFUN (Fmake_string, 2); extern Lisp_Object build_string (const char *); extern Lisp_Object make_string (const char *, EMACS_INT); PATCH 1 --------------------------------------------------- === modified file 'doc/misc/texinfo.tex' --- doc/misc/texinfo.tex 2011-04-06 05:07:27 +0000 +++ doc/misc/texinfo.tex 2011-05-16 00:51:54 +0000 @@ -3,7 +3,7 @@ % Load plain if necessary, i.e., if running under initex. \expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi % -\def\texinfoversion{2011-03-25.11} +\def\texinfoversion{2011-05-11.16} % % Copyright 1985, 1986, 1988, 1990, 1991, 1992, 1993, 1994, 1995, % 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, @@ -8424,7 +8424,7 @@ % % Latin1 (ISO-8859-1) character definitions. \def\latonechardefs{% - \gdef^^a0{~} + \gdef^^a0{\tie} \gdef^^a1{\exclamdown} \gdef^^a2{\missingcharmsg{CENT SIGN}} \gdef^^a3{{\pounds}} @@ -8546,7 +8546,7 @@ % Latin2 (ISO-8859-2) character definitions. \def\lattwochardefs{% - \gdef^^a0{~} + \gdef^^a0{\tie} \gdef^^a1{\ogonek{A}} \gdef^^a2{\u{}} \gdef^^a3{\L} @@ -9395,6 +9395,8 @@ \message{and turning on texinfo input format.} +\def^^L{\par} % remove \outer, so ^L can appear in an @comment + % DEL is a comment character, in case @c does not suffice. \catcode`\^^? = 14 === modified file 'lib/gnulib.mk' --- lib/gnulib.mk 2011-05-04 07:19:21 +0000 +++ lib/gnulib.mk 2011-05-16 00:51:54 +0000 @@ -167,7 +167,8 @@ ## begin gnulib module ignore-value -libgnu_a_SOURCES += ignore-value.h + +EXTRA_DIST += ignore-value.h ## end gnulib module ignore-value @@ -779,6 +780,7 @@ -e 's|@''GNULIB_GETLOGIN_R''@|$(GNULIB_GETLOGIN_R)|g' \ -e 's|@''GNULIB_GETPAGESIZE''@|$(GNULIB_GETPAGESIZE)|g' \ -e 's|@''GNULIB_GETUSERSHELL''@|$(GNULIB_GETUSERSHELL)|g' \ + -e 's|@''GNULIB_GROUP_MEMBER''@|$(GNULIB_GROUP_MEMBER)|g' \ -e 's|@''GNULIB_LCHOWN''@|$(GNULIB_LCHOWN)|g' \ -e 's|@''GNULIB_LINK''@|$(GNULIB_LINK)|g' \ -e 's|@''GNULIB_LINKAT''@|$(GNULIB_LINKAT)|g' \ @@ -817,6 +819,7 @@ -e 's|@''HAVE_GETHOSTNAME''@|$(HAVE_GETHOSTNAME)|g' \ -e 's|@''HAVE_GETLOGIN''@|$(HAVE_GETLOGIN)|g' \ -e 's|@''HAVE_GETPAGESIZE''@|$(HAVE_GETPAGESIZE)|g' \ + -e 's|@''HAVE_GROUP_MEMBER''@|$(HAVE_GROUP_MEMBER)|g' \ -e 's|@''HAVE_LCHOWN''@|$(HAVE_LCHOWN)|g' \ -e 's|@''HAVE_LINK''@|$(HAVE_LINK)|g' \ -e 's|@''HAVE_LINKAT''@|$(HAVE_LINKAT)|g' \ @@ -883,9 +886,10 @@ ## begin gnulib module verify if gl_GNULIB_ENABLED_verify -libgnu_a_SOURCES += verify.h endif +EXTRA_DIST += verify.h + ## end gnulib module verify ## begin gnulib module warn-on-use === modified file 'lib/intprops.h' --- lib/intprops.h 2011-01-30 19:22:02 +0000 +++ lib/intprops.h 2011-05-16 00:51:54 +0000 @@ -17,70 +17,298 @@ /* Written by Paul Eggert. */ -#ifndef GL_INTPROPS_H -# define GL_INTPROPS_H - -# include <limits.h> +#ifndef _GL_INTPROPS_H +#define _GL_INTPROPS_H + +#include <limits.h> + +/* Return a integer value, converted to the same type as the integer + expression E after integer type promotion. V is the unconverted value. + E should not have side effects. */ +#define _GL_INT_CONVERT(e, v) ((e) - (e) + (v)) /* The extra casts in the following macros work around compiler bugs, e.g., in Cray C 5.0.3.0. */ /* True if the arithmetic type T is an integer type. bool counts as an integer. */ -# define TYPE_IS_INTEGER(t) ((t) 1.5 == 1) +#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1) /* True if negative values of the signed integer type T use two's complement, ones' complement, or signed magnitude representation, respectively. Much GNU code assumes two's complement, but some people like to be portable to all possible C hosts. */ -# define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1) -# define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0) -# define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1) +#define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1) +#define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0) +#define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1) + +/* True if the signed integer expression E uses two's complement. */ +#define _GL_INT_TWOS_COMPLEMENT(e) (~ _GL_INT_CONVERT (e, 0) == -1) /* True if the arithmetic type T is signed. */ -# define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) - -/* The maximum and minimum values for the integer type T. These +#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) + +/* Return 1 if the integer expression E, after integer promotion, has + a signed type. E should not have side effects. */ +#define _GL_INT_SIGNED(e) (_GL_INT_CONVERT (e, -1) < 0) + + +/* Minimum and maximum values for integer types and expressions. These macros have undefined behavior if T is signed and has padding bits. If this is a problem for you, please let us know how to fix it for your host. */ -# define TYPE_MINIMUM(t) \ - ((t) (! TYPE_SIGNED (t) \ - ? (t) 0 \ - : TYPE_SIGNED_MAGNITUDE (t) \ - ? ~ (t) 0 \ + +/* The maximum and minimum values for the integer type T. */ +#define TYPE_MINIMUM(t) \ + ((t) (! TYPE_SIGNED (t) \ + ? (t) 0 \ + : TYPE_SIGNED_MAGNITUDE (t) \ + ? ~ (t) 0 \ : ~ TYPE_MAXIMUM (t))) -# define TYPE_MAXIMUM(t) \ - ((t) (! TYPE_SIGNED (t) \ - ? (t) -1 \ +#define TYPE_MAXIMUM(t) \ + ((t) (! TYPE_SIGNED (t) \ + ? (t) -1 \ : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1))) -/* Return zero if T can be determined to be an unsigned type. - Otherwise, return 1. - When compiling with GCC, INT_STRLEN_BOUND uses this macro to obtain a - tighter bound. Otherwise, it overestimates the true bound by one byte - when applied to unsigned types of size 2, 4, 16, ... bytes. - The symbol signed_type_or_expr__ is private to this header file. */ -# if __GNUC__ >= 2 -# define signed_type_or_expr__(t) TYPE_SIGNED (__typeof__ (t)) -# else -# define signed_type_or_expr__(t) 1 -# endif +/* The maximum and minimum values for the type of the expression E, + after integer promotion. E should not have side effects. */ +#define _GL_INT_MINIMUM(e) \ + (_GL_INT_SIGNED (e) \ + ? - _GL_INT_TWOS_COMPLEMENT (e) - _GL_SIGNED_INT_MAXIMUM (e) \ + : _GL_INT_CONVERT (e, 0)) +#define _GL_INT_MAXIMUM(e) \ + (_GL_INT_SIGNED (e) \ + ? _GL_SIGNED_INT_MAXIMUM (e) \ + : _GL_INT_CONVERT (e, -1)) +#define _GL_SIGNED_INT_MAXIMUM(e) \ + (((_GL_INT_CONVERT (e, 1) << (sizeof ((e) + 0) * CHAR_BIT - 2)) - 1) * 2 + 1) + + +/* Return 1 if the __typeof__ keyword works. This could be done by + 'configure', but for now it's easier to do it by hand. */ +#if 2 <= __GNUC__ || 0x5110 <= __SUNPRO_C +# define _GL_HAVE___TYPEOF__ 1 +#else +# define _GL_HAVE___TYPEOF__ 0 +#endif + +/* Return 1 if the integer type or expression T might be signed. Return 0 + if it is definitely unsigned. This macro does not evaluate its argument, + and expands to an integer constant expression. */ +#if _GL_HAVE___TYPEOF__ +# define _GL_SIGNED_TYPE_OR_EXPR(t) TYPE_SIGNED (__typeof__ (t)) +#else +# define _GL_SIGNED_TYPE_OR_EXPR(t) 1 +#endif /* Bound on length of the string representing an unsigned integer value representable in B bits. log10 (2.0) < 146/485. The smallest value of B where this bound is not tight is 2621. */ -# define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485) +#define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485) /* Bound on length of the string representing an integer type or expression T. Subtract 1 for the sign bit if T is signed, and then add 1 more for - a minus sign if needed. */ -# define INT_STRLEN_BOUND(t) \ - (INT_BITS_STRLEN_BOUND (sizeof (t) * CHAR_BIT - signed_type_or_expr__ (t)) \ - + signed_type_or_expr__ (t)) + a minus sign if needed. + + Because _GL_SIGNED_TYPE_OR_EXPR sometimes returns 0 when its argument is + signed, this macro may overestimate the true bound by one byte when + applied to unsigned types of size 2, 4, 16, ... bytes. */ +#define INT_STRLEN_BOUND(t) \ + (INT_BITS_STRLEN_BOUND (sizeof (t) * CHAR_BIT \ + - _GL_SIGNED_TYPE_OR_EXPR (t)) \ + + _GL_SIGNED_TYPE_OR_EXPR (t)) /* Bound on buffer size needed to represent an integer type or expression T, including the terminating null. */ -# define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1) - -#endif /* GL_INTPROPS_H */ +#define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1) + + +/* Range overflow checks. + + The INT_<op>_RANGE_OVERFLOW macros return 1 if the corresponding C + operators might not yield numerically correct answers due to + arithmetic overflow. They do not rely on undefined or + implementation-defined behavior. Their implementations are simple + and straightforward, but they are a bit harder to use than the + INT_<op>_OVERFLOW macros described below. + + Example usage: + + long int i = ...; + long int j = ...; + if (INT_MULTIPLY_RANGE_OVERFLOW (i, j, LONG_MIN, LONG_MAX)) + printf ("multiply would overflow"); + else + printf ("product is %ld", i * j); + + Restrictions on *_RANGE_OVERFLOW macros: + + These macros do not check for all possible numerical problems or + undefined or unspecified behavior: they do not check for division + by zero, for bad shift counts, or for shifting negative numbers. + + These macros may evaluate their arguments zero or multiple times, + so the arguments should not have side effects. The arithmetic + arguments (including the MIN and MAX arguments) must be of the same + integer type after the usual arithmetic conversions, and the type + must have minimum value MIN and maximum MAX. Unsigned types should + use a zero MIN of the proper type. + + These macros are tuned for constant MIN and MAX. For commutative + operations such as A + B, they are also tuned for constant B. */ + +/* Return 1 if A + B would overflow in [MIN,MAX] arithmetic. + See above for restrictions. */ +#define INT_ADD_RANGE_OVERFLOW(a, b, min, max) \ + ((b) < 0 \ + ? (a) < (min) - (b) \ + : (max) - (b) < (a)) + +/* Return 1 if A - B would overflow in [MIN,MAX] arithmetic. + See above for restrictions. */ +#define INT_SUBTRACT_RANGE_OVERFLOW(a, b, min, max) \ + ((b) < 0 \ + ? (max) + (b) < (a) \ + : (a) < (min) + (b)) + +/* Return 1 if - A would overflow in [MIN,MAX] arithmetic. + See above for restrictions. */ +#define INT_NEGATE_RANGE_OVERFLOW(a, min, max) \ + ((min) < 0 \ + ? (a) < - (max) \ + : 0 < (a)) + +/* Return 1 if A * B would overflow in [MIN,MAX] arithmetic. + See above for restrictions. */ +#define INT_MULTIPLY_RANGE_OVERFLOW(a, b, min, max) \ + ((b) < 0 \ + ? ((a) < 0 \ + ? (a) < (max) / (b) \ + : (b) < -1 && (min) / (b) < (a)) \ + : (0 < (b) \ + && ((a) < 0 \ + ? (a) < (min) / (b) \ + : (max) / (b) < (a)))) + +/* Return 1 if A / B would overflow in [MIN,MAX] arithmetic. + See above for restrictions. Do not check for division by zero. */ +#define INT_DIVIDE_RANGE_OVERFLOW(a, b, min, max) \ + ((min) < 0 && (b) == -1 && (a) < - (max)) + +/* Return 1 if A % B would overflow in [MIN,MAX] arithmetic. + See above for restrictions. Do not check for division by zero. + Mathematically, % should never overflow, but on x86-like hosts + INT_MIN % -1 traps, and the C standard permits this, so treat this + as an overflow too. */ +#define INT_REMAINDER_RANGE_OVERFLOW(a, b, min, max) \ + INT_DIVIDE_RANGE_OVERFLOW (a, b, min, max) + +/* Return 1 if A << B would overflow in [MIN,MAX] arithmetic. + See above for restrictions. Here, MIN and MAX are for A only, and B need + not be of the same type as the other arguments. The C standard says that + behavior is undefined for shifts unless 0 <= B < wordwidth, and that when + A is negative then A << B has undefined behavior and A >> B has + implementation-defined behavior, but do not check these other + restrictions. */ +#define INT_LEFT_SHIFT_RANGE_OVERFLOW(a, b, min, max) \ + ((a) < 0 \ + ? (a) < (min) >> (b) \ + : (max) >> (b) < (a)) + + +/* The _GL*_OVERFLOW macros have the same restrictions as the + *_RANGE_OVERFLOW macros, except that they do not assume that operands + (e.g., A and B) have the same type as MIN and MAX. Instead, they assume + that the result (e.g., A + B) has that type. */ +#define _GL_ADD_OVERFLOW(a, b, min, max) \ + ((min) < 0 ? INT_ADD_RANGE_OVERFLOW (a, b, min, max) \ + : (a) < 0 ? (b) <= (a) + (b) \ + : (b) < 0 ? (a) <= (a) + (b) \ + : (a) + (b) < (b)) +#define _GL_SUBTRACT_OVERFLOW(a, b, min, max) \ + ((min) < 0 ? INT_SUBTRACT_RANGE_OVERFLOW (a, b, min, max) \ + : (a) < 0 ? 1 \ + : (b) < 0 ? (a) - (b) <= (a) \ + : (a) < (b)) +#define _GL_MULTIPLY_OVERFLOW(a, b, min, max) \ + (((min) == 0 && (((a) < 0 && 0 < (b)) || ((b) < 0 && 0 < (a)))) \ + || INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max)) +#define _GL_DIVIDE_OVERFLOW(a, b, min, max) \ + ((min) < 0 ? (b) == _GL_INT_CONVERT (min, -1) && (a) < - (max) \ + : (a) < 0 ? (b) <= (a) + (b) - 1 \ + : (b) < 0 && (a) + (b) <= (a)) +#define _GL_REMAINDER_OVERFLOW(a, b, min, max) \ + ((min) < 0 ? (b) == _GL_INT_CONVERT (min, -1) && (a) < - (max) \ + : (a) < 0 ? (a) % (b) != ((max) - (b) + 1) % (b) \ + : (b) < 0 && ! _GL_UNSIGNED_NEG_MULTIPLE (a, b, max)) + +/* Return a nonzero value if A is a mathematical multiple of B, where + A is unsigned, B is negative, and MAX is the maximum value of A's + type. A's type must be the same as (A % B)'s type. Normally (A % + -B == 0) suffices, but things get tricky if -B would overflow. */ +#define _GL_UNSIGNED_NEG_MULTIPLE(a, b, max) \ + (((b) < -_GL_SIGNED_INT_MAXIMUM (b) \ + ? (_GL_SIGNED_INT_MAXIMUM (b) == (max) \ + ? (a) \ + : (a) % (_GL_INT_CONVERT (a, _GL_SIGNED_INT_MAXIMUM (b)) + 1)) \ + : (a) % - (b)) \ + == 0) + + +/* Integer overflow checks. + + The INT_<op>_OVERFLOW macros return 1 if the corresponding C operators + might not yield numerically correct answers due to arithmetic overflow. + They work correctly on all known practical hosts, and do not rely + on undefined behavior due to signed arithmetic overflow. + + Example usage: + + long int i = ...; + long int j = ...; + if (INT_MULTIPLY_OVERFLOW (i, j)) + printf ("multiply would overflow"); + else + printf ("product is %ld", i * j); + + These macros do not check for all possible numerical problems or + undefined or unspecified behavior: they do not check for division + by zero, for bad shift counts, or for shifting negative numbers. + + These macros may evaluate their arguments zero or multiple times, so the + arguments should not have side effects. + + These macros are tuned for their last argument being a constant. + + Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B, + A % B, and A << B would overflow, respectively. */ + +#define INT_ADD_OVERFLOW(a, b) \ + _GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW) +#define INT_SUBTRACT_OVERFLOW(a, b) \ + _GL_BINARY_OP_OVERFLOW (a, b, _GL_SUBTRACT_OVERFLOW) +#define INT_NEGATE_OVERFLOW(a) \ + INT_NEGATE_RANGE_OVERFLOW (a, _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a)) +#define INT_MULTIPLY_OVERFLOW(a, b) \ + _GL_BINARY_OP_OVERFLOW (a, b, _GL_MULTIPLY_OVERFLOW) +#define INT_DIVIDE_OVERFLOW(a, b) \ + _GL_BINARY_OP_OVERFLOW (a, b, _GL_DIVIDE_OVERFLOW) +#define INT_REMAINDER_OVERFLOW(a, b) \ + _GL_BINARY_OP_OVERFLOW (a, b, _GL_REMAINDER_OVERFLOW) +#define INT_LEFT_SHIFT_OVERFLOW(a, b) \ + INT_LEFT_SHIFT_RANGE_OVERFLOW (a, b, \ + _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a)) + +/* Return 1 if the expression A <op> B would overflow, + where OP_RESULT_OVERFLOW (A, B, MIN, MAX) does the actual test, + assuming MIN and MAX are the minimum and maximum for the result type. + + This macro assumes that A | B is a valid integer if both A and B are, + which is true of all known practical hosts. If this is a problem + for you, please let us know how to fix it for your host. */ +#define _GL_BINARY_OP_OVERFLOW(a, b, op_result_overflow) \ + op_result_overflow (a, b, \ + _GL_INT_MINIMUM ((a) | (b)), \ + _GL_INT_MAXIMUM ((a) | (b))) + +#endif /* _GL_INTPROPS_H */ === modified file 'lib/unistd.in.h' --- lib/unistd.in.h 2011-04-18 04:03:18 +0000 +++ lib/unistd.in.h 2011-05-16 00:51:54 +0000 @@ -871,6 +871,22 @@ #endif +#if @GNULIB_GROUP_MEMBER@ +/* Determine whether group id is in calling user's group list. */ +# if !@HAVE_GROUP_MEMBER@ +_GL_FUNCDECL_SYS (group_member, int, (gid_t gid)); +# endif +_GL_CXXALIAS_SYS (group_member, int, (gid_t gid)); +_GL_CXXALIASWARN (group_member); +#elif defined GNULIB_POSIXCHECK +# undef group_member +# if HAVE_RAW_DECL_GROUP_MEMBER +_GL_WARN_ON_USE (group_member, "group_member is unportable - " + "use gnulib module group-member for portability"); +# endif +#endif + + #if @GNULIB_LCHOWN@ /* Change the owner of FILE to UID (if UID is not -1) and the group of FILE to GID (if GID is not -1). Do not follow symbolic links. === modified file 'm4/unistd_h.m4' --- m4/unistd_h.m4 2011-04-18 04:03:18 +0000 +++ m4/unistd_h.m4 2011-05-16 00:51:54 +0000 @@ -1,4 +1,4 @@ -# unistd_h.m4 serial 55 +# unistd_h.m4 serial 56 dnl Copyright (C) 2006-2011 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -36,8 +36,8 @@ ]], [chown dup2 dup3 environ euidaccess faccessat fchdir fchownat fsync ftruncate getcwd getdomainname getdtablesize getgroups gethostname getlogin getlogin_r getpagesize getusershell setusershell - endusershell lchown link linkat lseek pipe pipe2 pread pwrite readlink - readlinkat rmdir sleep symlink symlinkat ttyname_r unlink unlinkat + endusershell group_member lchown link linkat lseek pipe pipe2 pread pwrite + readlink readlinkat rmdir sleep symlink symlinkat ttyname_r unlink unlinkat usleep]) ]) @@ -72,6 +72,7 @@ GNULIB_GETLOGIN_R=0; AC_SUBST([GNULIB_GETLOGIN_R]) GNULIB_GETPAGESIZE=0; AC_SUBST([GNULIB_GETPAGESIZE]) GNULIB_GETUSERSHELL=0; AC_SUBST([GNULIB_GETUSERSHELL]) + GNULIB_GROUP_MEMBER=0; AC_SUBST([GNULIB_GROUP_MEMBER]) GNULIB_LCHOWN=0; AC_SUBST([GNULIB_LCHOWN]) GNULIB_LINK=0; AC_SUBST([GNULIB_LINK]) GNULIB_LINKAT=0; AC_SUBST([GNULIB_LINKAT]) @@ -110,6 +111,7 @@ HAVE_GETHOSTNAME=1; AC_SUBST([HAVE_GETHOSTNAME]) HAVE_GETLOGIN=1; AC_SUBST([HAVE_GETLOGIN]) HAVE_GETPAGESIZE=1; AC_SUBST([HAVE_GETPAGESIZE]) + HAVE_GROUP_MEMBER=1; AC_SUBST([HAVE_GROUP_MEMBER]) HAVE_LCHOWN=1; AC_SUBST([HAVE_LCHOWN]) HAVE_LINK=1; AC_SUBST([HAVE_LINK]) HAVE_LINKAT=1; AC_SUBST([HAVE_LINKAT])
[Message part 3 (message/rfc822, inline)]
From: Paul Eggert <eggert <at> cs.ucla.edu> To: 8675-done <at> debbugs.gnu.org, 8664-done <at> debbugs.gnu.org Subject: committed fix into trunk Date: Tue, 17 May 2011 18:33:25 -0700Bzr 104265,which I just committed into the trunk, should contain the fix discussed above, so I'm marking this as "done". As requested I separated the gnulib merge into a separate commit, bzr 104264.
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