Files
mercury/runtime/mercury_string.c
Fergus Henderson 31eadee813 Fix a bug in petdr's recent changes to string__format that
Estimated hours taken: 1.5

Fix a bug in petdr's recent changes to string__format that
broke things in non-gc grades on sparcs.

runtime/mercury_string.c:
	In MR_make_string(), wrap calls to restore/save_transient_hp()
	around the call to MR_make_aligned_string_msg(), as mentioned
	in the documentation for MR_make_aligned_string_msg().

runtime/mercury_string.h:
	Document that calls to MR_make_string need to be wrapped inside
	calls to save/restore_transient_hp().

library/string.m:
	Wrap calls to MR_make_string inside calls to
	save/restore_transient_hp().
2000-09-14 15:24:51 +00:00

91 lines
1.9 KiB
C

/*
** Copyright (C) 2000 The University of Melbourne.
** This file may only be copied under the terms of the GNU Library General
** Public License - see the file COPYING.LIB in the Mercury distribution.
*/
/* mercury_string.c - string handling */
#include "mercury_imp.h"
#include "mercury_string.h"
#if defined(HAVE__VSNPRINTF) && ! defined(HAVE_VSNPRINTF)
#define vsnprintf _vsnprintf
#endif
#define BUFFER_SIZE 4096
MR_String
MR_make_string(MR_Code *proclabel, const char *fmt, ...) {
va_list ap;
MR_String result;
int n;
char *p;
#if defined(HAVE_VSNPRINTF) || defined(HAVE__VSNPRINTF)
int size = BUFFER_SIZE;
char fixed[BUFFER_SIZE];
bool dynamically_allocated = FALSE;
/*
** On the first iteration we try with a fixed-size buffer.
** If that didn't work, use a dynamically allocated array twice
** the size of the fixed array and keep growing the array until
** the string fits.
*/
p = fixed;
while (1) {
/* Try to print in the allocated space. */
va_start(ap, fmt);
n = vsnprintf(p, size, fmt, ap);
va_end(ap);
/* If that worked, return the string. */
if (n > -1 && n < size) {
break;
}
/* Else try again with more space. */
if (n > -1) { /* glibc 2.1 */
size = n + 1; /* precisely what is needed */
} else { /* glibc 2.0 */
size *= 2; /* twice the old size */
}
if (!dynamically_allocated) {
p = MR_NEW_ARRAY(char, size);
dynamically_allocated = TRUE;
} else {
p = MR_RESIZE_ARRAY(p, char, size);
}
}
#else
/*
** It is possible for this buffer to overflow and
** then bad things may happen
*/
char fixed[40960];
va_start(ap, fmt);
n = vsprintf(fixed, fmt, ap);
va_end(ap);
p = fixed;
#endif
restore_transient_hp();
MR_allocate_aligned_string_msg(result, strlen(p),
proclabel);
save_transient_hp();
strcpy(result, p);
#ifdef HAVE_VSNPRINTF
if (dynamically_allocated) {
MR_free(p);
}
#endif
return result;
}