Commit 825cd63c authored by Eli Zaretskii's avatar Eli Zaretskii

Improve doprnt and its use in verror. (Bug#8545)

 src/doprnt.c (doprnt): Document the set of format control sequences
 supported by the function.  Use SAFE_ALLOCA instead of always
 using `alloca'.
 src/eval.c (verror): Don't limit the buffer size at size_max-1, that
 is one byte too soon.  Don't use xrealloc; instead xfree and
 xmalloc anew.
parent e2822bd2
2011-04-25 Eli Zaretskii <eliz@gnu.org>
Improve doprnt and its use in verror. (Bug#8545)
* doprnt.c (doprnt): Document the set of format control sequences
supported by the function. Use SAFE_ALLOCA instead of always
using `alloca'.
* eval.c (verror): Don't limit the buffer size at size_max-1, that
is one byte too soon. Don't use xrealloc; instead xfree and
xmalloc anew.
2011-04-24 Teodor Zlatanov <tzz@lifelogs.com>
* gnutls.h: Add GNUTLS_STAGE_CALLBACKS enum to denote we're in the
......
......@@ -43,10 +43,54 @@ along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
OTOH, this function supports only a small subset of the standard C formatted
output facilities. E.g., %u and %ll are not supported, and precision is
largely ignored except for converting floating-point values. However, this
is okay, as this function is supposed to be called from `error' and similar
functions, and thus does not need to support features beyond those in
`Fformat', which is used by `error' on the Lisp level. */
ignored %s and %c conversions. (See below for the detailed documentation of
what is supported.) However, this is okay, as this function is supposed to
be called from `error' and similar functions, and thus does not need to
support features beyond those in `Fformat', which is used by `error' on the
Lisp level. */
/* This function supports the following %-sequences in the `format'
argument:
%s means print a string argument.
%S is silently treated as %s, for loose compatibility with `Fformat'.
%d means print a `signed int' argument in decimal.
%l means print a `long int' argument in decimal.
%o means print an `unsigned int' argument in octal.
%x means print an `unsigned int' argument in hex.
%e means print a `double' argument in exponential notation.
%f means print a `double' argument in decimal-point notation.
%g means print a `double' argument in exponential notation
or in decimal-point notation, whichever uses fewer characters.
%c means print a `signed int' argument as a single character.
%% means produce a literal % character.
A %-sequence may contain optional flag, width, and precision specifiers, as
follows:
%<flags><width><precision>character
where flags is [+ -0l], width is [0-9]+, and precision is .[0-9]+
The + flag character inserts a + before any positive number, while a space
inserts a space before any positive number; these flags only affect %d, %l,
%o, %x, %e, %f, and %g sequences. The - and 0 flags affect the width
specifier, as described below.
The l (lower-case letter ell) flag is a `long' data type modifier: it is
supported for %d, %o, and %x conversions of integral arguments, and means
that the respective argument is to be treated as `long int' or `unsigned
long int'. The EMACS_INT data type should use this modifier.
The width specifier supplies a lower limit for the length of the printed
representation. The padding, if any, normally goes on the left, but it goes
on the right if the - flag is present. The padding character is normally a
space, but (for numerical arguments only) it is 0 if the 0 flag is present.
The - flag takes precedence over the 0 flag.
For %e, %f, and %g sequences, the number after the "." in the precision
specifier says how many decimal places to show; if zero, the decimal point
itself is omitted. For %s and %S, the precision specifier is ignored. */
#include <config.h>
#include <stdio.h>
......@@ -79,9 +123,8 @@ along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
terminated at position FORMAT_END.
Output goes in BUFFER, which has room for BUFSIZE chars.
If the output does not fit, truncate it to fit.
Returns the number of bytes stored into BUFFER.
ARGS points to the vector of arguments, and NARGS says how many.
A double counts as two arguments.
Returns the number of bytes stored into BUFFER, excluding
the terminating null byte. Output is always null-terminated.
String arguments are passed as C strings.
Integers are passed as C integers. */
......@@ -110,6 +153,7 @@ doprnt (char *buffer, register size_t bufsize, const char *format,
char *fmtcpy;
int minlen;
char charbuf[MAX_MULTIBYTE_LENGTH + 1]; /* Used for %c. */
USE_SAFE_ALLOCA;
if (format_end == 0)
format_end = format + strlen (format);
......@@ -117,7 +161,7 @@ doprnt (char *buffer, register size_t bufsize, const char *format,
if ((format_end - format + 1) < sizeof (fixed_buffer))
fmtcpy = fixed_buffer;
else
fmtcpy = (char *) alloca (format_end - format + 1);
SAFE_ALLOCA (fmtcpy, char *, format_end - format + 1);
bufsize--;
......@@ -342,5 +386,7 @@ doprnt (char *buffer, register size_t bufsize, const char *format,
xfree (big_buffer);
*bufptr = 0; /* Make sure our string ends with a '\0' */
SAFE_FREE ();
return bufptr - buffer;
}
......@@ -2012,15 +2012,14 @@ verror (const char *m, va_list ap)
break;
if (size <= size_max / 2)
size *= 2;
else if (size < size_max - 1)
size = size_max - 1;
else if (size < size_max)
size = size_max;
else
break; /* and leave the message truncated */
if (buffer == buf)
if (buffer != buf)
xfree (buffer);
buffer = (char *) xmalloc (size);
else
buffer = (char *) xrealloc (buffer, size);
}
string = make_string (buffer, used);
......
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