Re: [PATCHES] [pgsql-hackers-win32] Repleacement for src/port/snprintf.c

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
Cc: Nicolai Tufar <ntufar(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Peter Eisentraut <peter_e(at)gmx(dot)net>, Magnus Hagander <mha(at)sollentuna(dot)net>, pgsql-hackers(at)postgresql(dot)org, pgsql-hackers-win32(at)postgresql(dot)org, pgsql-patches(at)postgresql(dot)org, devrim(at)gunduz(dot)org
Subject: Re: [PATCHES] [pgsql-hackers-win32] Repleacement for src/port/snprintf.c
Date: 2005-02-22 03:53:08
Message-ID: 200502220353.j1M3r8909318@candle.pha.pa.us
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Lists: pgsql-hackers pgsql-hackers-win32 pgsql-patches


Applied.

---------------------------------------------------------------------------

Bruce Momjian wrote:
> Nicolai Tufar wrote:
> > Hello all,
> >
> > I would like to submit my changes to src/port/snprintf.c to
> > enable %n$ format placeholder replacement in snprintf() and
> > vsnprintf(). Additionally I implemented a trivial printf().
> >
> > I also attach a diff for configure.in to include snprintf.o
> > in pgport but I am sure it is not the right thing to do.
> > Could someone give a hint on where I need to place such a
> > definition.
> >
> > Please review my patch. as Tom Lane pointed out there
> > are 150 messages in the following files that do not print
> > properly:
>
> It took me a while to understand this but I get it now. This is the
> best explanation I have seen, from Linux 2.6:
>
> One can also specify explicitly which argument is taken, at each place
> where an argument is required, by writing '%m$' instead of '%' and '*m$'
> instead of '*', where the decimal integer m denotes the position in the
> argument list of the desired argument, indexed starting from 1. Thus,
>
> printf("%*d", width, num);
>
> and
>
> printf("%2$*1$d", width, num);
>
> are equivalent. The second style allows repeated references to the
> same argument. The C99 standard does not include the style using '$',
> which comes from the Single Unix Specification. If the style using '$'
> is used, it must be used throughout for all conversions taking an
> argument and all width and precision arguments, but it may be mixed with
> '%%' formats which do not consume an argument. There may be no gaps in
> the numbers of arguments specified using '$'; for example, if
> arguments 1 and 3 are specified, argument 2 must also be specified
> somewhere in the format string.
>
> I can see why this would be useful for translations because it uncouples
> the order of the printf arguments from the printf string. However, I
> have learned that Win32, HP-UX, NetBSD 2.0, and BSD/OS do not support
> this. This is probably because it is not in C99 but in SUS (see above).
>
> Anyway, this is too large to put into 8.0, but I am attaching a patch
> for 8.1 that has the proper configure tests to check if the C library
> supports this behavior. If it does not, the build will use our
> port/snprintf.c.
>
> One problem with that is that our snprintf.c is not thread-safe. Seems
> the increases use of it will require us to fix this soon. I have added
> to TODO:
>
> * Make src/port/snprintf.c thread-safe
>
> One change to the original port is that there was a define of a union
> with no name:
>
> + union{
> + void* value;
> + long_long numvalue;
> + double fvalue;
> + int charvalue;
> + };
>
> As far as I know a union with no name is illegal. I just removed the
> "union {" and the closing brace.
>
> --
> Bruce Momjian | http://candle.pha.pa.us
> pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
> + If your life is a hard drive, | 13 Roberts Road
> + Christ can be your backup. | Newtown Square, Pennsylvania 19073

> Index: configure
> ===================================================================
> RCS file: /cvsroot/pgsql/configure,v
> retrieving revision 1.425
> diff -c -c -r1.425 configure
> *** configure 18 Jan 2005 05:23:35 -0000 1.425
> --- configure 13 Feb 2005 23:50:46 -0000
> ***************
> *** 12162,12167 ****
> --- 12162,12224 ----
> done
>
>
> + echo "$as_me:$LINENO: checking printf supports argument control" >&5
> + echo $ECHO_N "checking printf supports argument control... $ECHO_C" >&6
> + if test "${pgac_cv_printf_arg_control+set}" = set; then
> + echo $ECHO_N "(cached) $ECHO_C" >&6
> + else
> + if test "$cross_compiling" = yes; then
> + pgac_cv_printf_arg_control=cross
> + else
> + cat >conftest.$ac_ext <<_ACEOF
> + #line $LINENO "configure"
> + #include "confdefs.h"
> + #include <stdio.h>
> +
> + int does_printf_have_arg_control()
> + {
> + char buf[100];
> +
> + /* can it swap arguments? */
> + snprintf(buf, 100, "%2$d|%1$d", 3, 4);
> + if (strcmp(buf, "4|3") != 0)
> + return 0;
> + return 1;
> + }
> + main() {
> + exit(! does_printf_have_arg_control());
> + }
> + _ACEOF
> + rm -f conftest$ac_exeext
> + if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
> + (eval $ac_link) 2>&5
> + ac_status=$?
> + echo "$as_me:$LINENO: \$? = $ac_status" >&5
> + (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
> + { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
> + (eval $ac_try) 2>&5
> + ac_status=$?
> + echo "$as_me:$LINENO: \$? = $ac_status" >&5
> + (exit $ac_status); }; }; then
> + pgac_cv_printf_arg_control=yes
> + else
> + echo "$as_me: program exited with status $ac_status" >&5
> + echo "$as_me: failed program was:" >&5
> + cat conftest.$ac_ext >&5
> + ( exit $ac_status )
> + pgac_cv_printf_arg_control=no
> + fi
> + rm -f core core.* *.core conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
> + fi
> +
> + fi
> + echo "$as_me:$LINENO: result: $pgac_cv_printf_arg_control" >&5
> + echo "${ECHO_T}$pgac_cv_printf_arg_control" >&6
> +
> + # cross compiler should use our snprintf too
> + if test $pgac_cv_printf_arg_control != yes ; then
> + pgac_need_repl_snprintf=yes
> + fi
>
> # Check whether <stdio.h> declares snprintf() and vsnprintf(); if not,
> # include/c.h will provide declarations. Note this is a separate test
> Index: configure.in
> ===================================================================
> RCS file: /cvsroot/pgsql/configure.in,v
> retrieving revision 1.399
> diff -c -c -r1.399 configure.in
> *** configure.in 18 Jan 2005 05:23:36 -0000 1.399
> --- configure.in 13 Feb 2005 23:50:47 -0000
> ***************
> *** 881,886 ****
> --- 881,891 ----
> AC_CHECK_FUNCS(snprintf, [], pgac_need_repl_snprintf=yes)
> AC_CHECK_FUNCS(vsnprintf, [], pgac_need_repl_snprintf=yes)
>
> + PGAC_FUNC_PRINTF_ARG_CONTROL
> + # cross compiler should use our snprintf too
> + if test $pgac_cv_printf_arg_control != yes ; then
> + pgac_need_repl_snprintf=yes
> + fi
>
> # Check whether <stdio.h> declares snprintf() and vsnprintf(); if not,
> # include/c.h will provide declarations. Note this is a separate test
> ***************
> *** 1069,1074 ****
> --- 1074,1081 ----
> [AC_MSG_RESULT([cross-compiling])])
>
>
> + dnl 64-bit section
> + dnl
> dnl Check to see if we have a working 64-bit integer type.
> dnl This breaks down into two steps:
> dnl (1) figure out if the compiler has a 64-bit int type with working
> Index: config/c-library.m4
> ===================================================================
> RCS file: /cvsroot/pgsql/config/c-library.m4,v
> retrieving revision 1.29
> diff -c -c -r1.29 c-library.m4
> *** config/c-library.m4 16 Dec 2004 17:48:26 -0000 1.29
> --- config/c-library.m4 13 Feb 2005 23:50:48 -0000
> ***************
> *** 266,268 ****
> --- 266,301 ----
> LONG_LONG_INT_FORMAT=$pgac_cv_snprintf_long_long_int_format;;
> *) AC_MSG_RESULT(none);;
> esac])# PGAC_FUNC_SNPRINTF_LONG_LONG_INT_FORMAT
> +
> +
> + # PGAC_FUNC_PRINTF_ARG_CONTROL
> + # ---------------------------------------
> + # Determine if printf supports %1$ argument selection, e.g. %5$ selects
> + # the fifth argument after the printf print string.
> + # This is not in the C99 standard, but in the Single Unix Specification (SUS).
> + # It is used in our langauge translation strings.
> + #
> + AC_DEFUN([PGAC_FUNC_PRINTF_ARG_CONTROL],
> + [AC_MSG_CHECKING([printf supports argument control])
> + AC_CACHE_VAL(pgac_cv_printf_arg_control,
> + [AC_TRY_RUN([#include <stdio.h>
> +
> + int does_printf_have_arg_control()
> + {
> + char buf[100];
> +
> + /* can it swap arguments? */
> + snprintf(buf, 100, "%2$d|%1$d", 3, 4);
> + if (strcmp(buf, "4|3") != 0)
> + return 0;
> + return 1;
> + }
> + main() {
> + exit(! does_printf_have_arg_control());
> + }],
> + [pgac_cv_printf_arg_control=yes],
> + [pgac_cv_printf_arg_control=no],
> + [pgac_cv_printf_arg_control=cross])
> + ])dnl AC_CACHE_VAL
> + AC_MSG_RESULT([$pgac_cv_printf_arg_control])
> + ])# PGAC_FUNC_PRINTF_ARG_CONTROL
> Index: src/port/snprintf.c
> ===================================================================
> RCS file: /cvsroot/pgsql/src/port/snprintf.c,v
> retrieving revision 1.4
> diff -c -c -r1.4 snprintf.c
> *** src/port/snprintf.c 29 Aug 2004 05:07:02 -0000 1.4
> --- src/port/snprintf.c 13 Feb 2005 23:50:56 -0000
> ***************
> *** 57,62 ****
> --- 57,66 ----
> typedef unsigned long ulong_long;
> #endif
>
> + #ifndef NL_ARGMAX
> + #define NL_ARGMAX 4096
> + #endif
> +
> /*
> ** SNPRINTF, VSNPRINT -- counted versions of printf
> **
> ***************
> *** 85,93 ****
> --- 89,115 ----
>
> int snprintf(char *str, size_t count, const char *fmt,...);
> int vsnprintf(char *str, size_t count, const char *fmt, va_list args);
> + int printf(const char *format, ...);
> static void dopr(char *buffer, const char *format, va_list args);
>
> int
> + printf(const char *fmt,...)
> + {
> + int len;
> + va_list args;
> + static char* buffer[4096];
> + char* p;
> +
> + va_start(args, fmt);
> + len = vsnprintf((char*)buffer, (size_t)4096, fmt, args);
> + va_end(args);
> + p = (char*)buffer;
> + for(;*p;p++)
> + putchar(*p);
> + return len;
> + }
> +
> + int
> snprintf(char *str, size_t count, const char *fmt,...)
> {
> int len;
> ***************
> *** 124,129 ****
> --- 146,155 ----
>
> static char *output;
>
> + #define FMTSTR 1
> + #define FMTNUM 2
> + #define FMTFLOAT 3
> + #define FMTCHAR 4
>
> static void
> dopr(char *buffer, const char *format, va_list args)
> ***************
> *** 139,145 ****
> --- 165,198 ----
> int ljust;
> int len;
> int zpad;
> + int i;
> + const char* format_save;
> + const char* fmtbegin;
> + int fmtpos = 1;
> + int realpos = 0;
> + int position;
> + static struct{
> + const char* fmtbegin;
> + const char* fmtend;
> + void* value;
> + long_long numvalue;
> + double fvalue;
> + int charvalue;
> + int ljust;
> + int len;
> + int zpad;
> + int maxwidth;
> + int base;
> + int dosign;
> + char type;
> + int precision;
> + int pointflag;
> + char func;
> + int realpos;
> + } fmtpar[NL_ARGMAX+1], *fmtparptr[NL_ARGMAX+1];
> +
>
> + format_save = format;
> output = buffer;
> while ((ch = *format++))
> {
> ***************
> *** 148,161 ****
> case '%':
> ljust = len = zpad = maxwidth = 0;
> longflag = longlongflag = pointflag = 0;
> nextch:
> ch = *format++;
> switch (ch)
> {
> case 0:
> ! dostr("**end of format**", 0);
> ! *output = '\0';
> ! return;
> case '-':
> ljust = 1;
> goto nextch;
> --- 201,215 ----
> case '%':
> ljust = len = zpad = maxwidth = 0;
> longflag = longlongflag = pointflag = 0;
> + fmtbegin = format - 1;
> + realpos = 0;
> + position = 0;
> nextch:
> ch = *format++;
> switch (ch)
> {
> case 0:
> ! goto performpr;
> case '-':
> ljust = 1;
> goto nextch;
> ***************
> *** 174,180 ****
> --- 228,241 ----
> if (pointflag)
> maxwidth = maxwidth * 10 + ch - '0';
> else
> + {
> len = len * 10 + ch - '0';
> + position = position * 10 + ch - '0';
> + }
> + goto nextch;
> + case '$':
> + realpos = position;
> + len = 0;
> goto nextch;
> case '*':
> if (pointflag)
> ***************
> *** 203,209 ****
> }
> else
> value = va_arg(args, unsigned int);
> ! fmtnum(value, 10, 0, ljust, len, zpad);
> break;
> case 'o':
> case 'O':
> --- 264,280 ----
> }
> else
> value = va_arg(args, unsigned int);
> ! fmtpar[fmtpos].fmtbegin = fmtbegin;
> ! fmtpar[fmtpos].fmtend = format;
> ! fmtpar[fmtpos].numvalue = value;
> ! fmtpar[fmtpos].base = 10;
> ! fmtpar[fmtpos].dosign = 0;
> ! fmtpar[fmtpos].ljust = ljust;
> ! fmtpar[fmtpos].len = len;
> ! fmtpar[fmtpos].zpad = zpad;
> ! fmtpar[fmtpos].func = FMTNUM;
> ! fmtpar[fmtpos].realpos = realpos?realpos:fmtpos;
> ! fmtpos++;
> break;
> case 'o':
> case 'O':
> ***************
> *** 217,223 ****
> }
> else
> value = va_arg(args, unsigned int);
> ! fmtnum(value, 8, 0, ljust, len, zpad);
> break;
> case 'd':
> case 'D':
> --- 288,304 ----
> }
> else
> value = va_arg(args, unsigned int);
> ! fmtpar[fmtpos].fmtbegin = fmtbegin;
> ! fmtpar[fmtpos].fmtend = format;
> ! fmtpar[fmtpos].numvalue = value;
> ! fmtpar[fmtpos].base = 8;
> ! fmtpar[fmtpos].dosign = 0;
> ! fmtpar[fmtpos].ljust = ljust;
> ! fmtpar[fmtpos].len = len;
> ! fmtpar[fmtpos].zpad = zpad;
> ! fmtpar[fmtpos].func = FMTNUM;
> ! fmtpar[fmtpos].realpos = realpos?realpos:fmtpos;
> ! fmtpos++;
> break;
> case 'd':
> case 'D':
> ***************
> *** 230,236 ****
> }
> else
> value = va_arg(args, int);
> ! fmtnum(value, 10, 1, ljust, len, zpad);
> break;
> case 'x':
> if (longflag)
> --- 311,327 ----
> }
> else
> value = va_arg(args, int);
> ! fmtpar[fmtpos].fmtbegin = fmtbegin;
> ! fmtpar[fmtpos].fmtend = format;
> ! fmtpar[fmtpos].numvalue = value;
> ! fmtpar[fmtpos].base = 10;
> ! fmtpar[fmtpos].dosign = 1;
> ! fmtpar[fmtpos].ljust = ljust;
> ! fmtpar[fmtpos].len = len;
> ! fmtpar[fmtpos].zpad = zpad;
> ! fmtpar[fmtpos].func = FMTNUM;
> ! fmtpar[fmtpos].realpos = realpos?realpos:fmtpos;
> ! fmtpos++;
> break;
> case 'x':
> if (longflag)
> ***************
> *** 242,248 ****
> }
> else
> value = va_arg(args, unsigned int);
> ! fmtnum(value, 16, 0, ljust, len, zpad);
> break;
> case 'X':
> if (longflag)
> --- 333,349 ----
> }
> else
> value = va_arg(args, unsigned int);
> ! fmtpar[fmtpos].fmtbegin = fmtbegin;
> ! fmtpar[fmtpos].fmtend = format;
> ! fmtpar[fmtpos].numvalue = value;
> ! fmtpar[fmtpos].base = 16;
> ! fmtpar[fmtpos].dosign = 0;
> ! fmtpar[fmtpos].ljust = ljust;
> ! fmtpar[fmtpos].len = len;
> ! fmtpar[fmtpos].zpad = zpad;
> ! fmtpar[fmtpos].func = FMTNUM;
> ! fmtpar[fmtpos].realpos = realpos?realpos:fmtpos;
> ! fmtpos++;
> break;
> case 'X':
> if (longflag)
> ***************
> *** 254,260 ****
> }
> else
> value = va_arg(args, unsigned int);
> ! fmtnum(value, -16, 0, ljust, len, zpad);
> break;
> case 's':
> strvalue = va_arg(args, char *);
> --- 355,371 ----
> }
> else
> value = va_arg(args, unsigned int);
> ! fmtpar[fmtpos].fmtbegin = fmtbegin;
> ! fmtpar[fmtpos].fmtend = format;
> ! fmtpar[fmtpos].numvalue = value;
> ! fmtpar[fmtpos].base = -16;
> ! fmtpar[fmtpos].dosign = 1;
> ! fmtpar[fmtpos].ljust = ljust;
> ! fmtpar[fmtpos].len = len;
> ! fmtpar[fmtpos].zpad = zpad;
> ! fmtpar[fmtpos].func = FMTNUM;
> ! fmtpar[fmtpos].realpos = realpos?realpos:fmtpos;
> ! fmtpos++;
> break;
> case 's':
> strvalue = va_arg(args, char *);
> ***************
> *** 262,273 ****
> {
> if (pointflag && len > maxwidth)
> len = maxwidth; /* Adjust padding */
> ! fmtstr(strvalue, ljust, len, zpad, maxwidth);
> }
> break;
> case 'c':
> ch = va_arg(args, int);
> ! dopr_outch(ch);
> break;
> case 'e':
> case 'E':
> --- 373,398 ----
> {
> if (pointflag && len > maxwidth)
> len = maxwidth; /* Adjust padding */
> ! fmtpar[fmtpos].fmtbegin = fmtbegin;
> ! fmtpar[fmtpos].fmtend = format;
> ! fmtpar[fmtpos].value = strvalue;
> ! fmtpar[fmtpos].ljust = ljust;
> ! fmtpar[fmtpos].len = len;
> ! fmtpar[fmtpos].zpad = zpad;
> ! fmtpar[fmtpos].maxwidth = maxwidth;
> ! fmtpar[fmtpos].func = FMTSTR;
> ! fmtpar[fmtpos].realpos = realpos?realpos:fmtpos;
> ! fmtpos++;
> }
> break;
> case 'c':
> ch = va_arg(args, int);
> ! fmtpar[fmtpos].fmtbegin = fmtbegin;
> ! fmtpar[fmtpos].fmtend = format;
> ! fmtpar[fmtpos].charvalue = ch;
> ! fmtpar[fmtpos].func = FMTCHAR;
> ! fmtpar[fmtpos].realpos = realpos?realpos:fmtpos;
> ! fmtpos++;
> break;
> case 'e':
> case 'E':
> ***************
> *** 275,285 ****
> case 'g':
> case 'G':
> fvalue = va_arg(args, double);
> ! fmtfloat(fvalue, ch, ljust, len, maxwidth, pointflag);
> break;
> case '%':
> ! dopr_outch(ch);
> ! continue;
> default:
> dostr("???????", 0);
> }
> --- 400,419 ----
> case 'g':
> case 'G':
> fvalue = va_arg(args, double);
> ! fmtpar[fmtpos].fmtbegin = fmtbegin;
> ! fmtpar[fmtpos].fmtend = format;
> ! fmtpar[fmtpos].fvalue = fvalue;
> ! fmtpar[fmtpos].type = ch;
> ! fmtpar[fmtpos].ljust = ljust;
> ! fmtpar[fmtpos].len = len;
> ! fmtpar[fmtpos].maxwidth = maxwidth;
> ! fmtpar[fmtpos].pointflag = pointflag;
> ! fmtpar[fmtpos].func = FMTFLOAT;
> ! fmtpar[fmtpos].realpos = realpos?realpos:fmtpos;
> ! fmtpos++;
> break;
> case '%':
> ! break;
> default:
> dostr("???????", 0);
> }
> ***************
> *** 289,294 ****
> --- 423,475 ----
> break;
> }
> }
> + performpr:
> + /* shuffle pointers */
> + for(i = 1; i < fmtpos; i++)
> + {
> + fmtparptr[i] = &fmtpar[fmtpar[i].realpos];
> + }
> + output = buffer;
> + format = format_save;
> + while ((ch = *format++))
> + {
> + for(i = 1; i < fmtpos; i++)
> + {
> + if(ch == '%' && *format == '%')
> + {
> + format++;
> + continue;
> + }
> + if(fmtpar[i].fmtbegin == format - 1)
> + {
> + switch(fmtparptr[i]->func){
> + case FMTSTR:
> + fmtstr(fmtparptr[i]->value, fmtparptr[i]->ljust,
> + fmtparptr[i]->len, fmtparptr[i]->zpad,
> + fmtparptr[i]->maxwidth);
> + break;
> + case FMTNUM:
> + fmtnum(fmtparptr[i]->numvalue, fmtparptr[i]->base,
> + fmtparptr[i]->dosign, fmtparptr[i]->ljust,
> + fmtparptr[i]->len, fmtparptr[i]->zpad);
> + break;
> + case FMTFLOAT:
> + fmtfloat(fmtparptr[i]->fvalue, fmtparptr[i]->type,
> + fmtparptr[i]->ljust, fmtparptr[i]->len,
> + fmtparptr[i]->precision, fmtparptr[i]->pointflag);
> + break;
> + case FMTCHAR:
> + dopr_outch(fmtparptr[i]->charvalue);
> + break;
> + }
> + format = fmtpar[i].fmtend;
> + goto nochar;
> + }
> + }
> + dopr_outch(ch);
> + nochar:
> + /* nothing */
> + }
> *output = '\0';
> }
>

>
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--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073

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