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runtime/mercury_string.c:
Fix a bug where MR_make_string introduced a space leak under windows
when the created string was greater then the fixed buffer size as
the conditional compilation wasn't including the call to MR_free.
94 lines
2.0 KiB
C
94 lines
2.0 KiB
C
/*
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** Copyright (C) 2000-2001 The University of Melbourne.
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** This file may only be copied under the terms of the GNU Library General
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** Public License - see the file COPYING.LIB in the Mercury distribution.
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*/
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/* mercury_string.c - string handling */
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#include "mercury_imp.h"
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#include "mercury_string.h"
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#if defined(HAVE__VSNPRINTF) && ! defined(HAVE_VSNPRINTF)
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#define vsnprintf _vsnprintf
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#endif
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#if defined(HAVE_VSNPRINTF) || defined(HAVE__VSNPRINTF)
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#define MR_HAVE_A_VSNPRINTF
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#endif
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#define BUFFER_SIZE 4096
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MR_String
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MR_make_string(MR_Code *proclabel, const char *fmt, ...) {
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va_list ap;
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MR_String result;
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int n;
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char *p;
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#ifdef MR_HAVE_A_VSNPRINTF
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int size = BUFFER_SIZE;
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char fixed[BUFFER_SIZE];
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bool dynamically_allocated = FALSE;
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/*
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** On the first iteration we try with a fixed-size buffer.
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** If that didn't work, use a dynamically allocated array twice
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** the size of the fixed array and keep growing the array until
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** the string fits.
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*/
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p = fixed;
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while (1) {
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/* Try to print in the allocated space. */
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va_start(ap, fmt);
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n = vsnprintf(p, size, fmt, ap);
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va_end(ap);
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/* If that worked, return the string. */
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if (n > -1 && n < size) {
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break;
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}
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/* Else try again with more space. */
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if (n > -1) { /* glibc 2.1 */
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size = n + 1; /* precisely what is needed */
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} else { /* glibc 2.0 */
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size *= 2; /* twice the old size */
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}
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if (!dynamically_allocated) {
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p = MR_NEW_ARRAY(char, size);
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dynamically_allocated = TRUE;
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} else {
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p = MR_RESIZE_ARRAY(p, char, size);
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}
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}
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#else
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/*
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** It is possible for this buffer to overflow and
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** then bad things may happen
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*/
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char fixed[40960];
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va_start(ap, fmt);
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n = vsprintf(fixed, fmt, ap);
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va_end(ap);
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p = fixed;
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#endif
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MR_restore_transient_hp();
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MR_allocate_aligned_string_msg(result, strlen(p), proclabel);
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MR_save_transient_hp();
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strcpy(result, p);
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#ifdef MR_HAVE_A_VSNPRINTF
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if (dynamically_allocated) {
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MR_free(p);
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}
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#endif
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return result;
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}
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