diff options
Diffstat (limited to 'src/vasprintf.c')
-rw-r--r-- | src/vasprintf.c | 650 |
1 files changed, 650 insertions, 0 deletions
diff --git a/src/vasprintf.c b/src/vasprintf.c new file mode 100644 index 0000000..940e8a4 --- /dev/null +++ b/src/vasprintf.c @@ -0,0 +1,650 @@ +/* + * Copyright (c) Ian F. Darwin 1986-1995. + * Software written by Ian F. Darwin and others; + * maintained 1995-present by Christos Zoulas and others. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice immediately at the beginning of the file, without modification, + * this list of conditions, and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR + * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ +/*########################################################################### + # # + # vasprintf # + # # + # Copyright (c) 2002-2005 David TAILLANDIER # + # # + ###########################################################################*/ + +/* + +This software is distributed under the "modified BSD licence". + +This software is also released with GNU license (GPL) in another file (same +source-code, only license differ). + + + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + +Redistributions of source code must retain the above copyright notice, this +list of conditions and the following disclaimer. Redistributions in binary +form must reproduce the above copyright notice, this list of conditions and +the following disclaimer in the documentation and/or other materials +provided with the distribution. The name of the author may not be used to +endorse or promote products derived from this software without specific +prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED +WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO +EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; +OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, +WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR +OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF +ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +==================== + +Hacked from xnprintf version of 26th February 2005 to provide only +vasprintf by Reuben Thomas <rrt@sc3d.org>. + +==================== + + +'printf' function family use the following format string: + +%[flag][width][.prec][modifier]type + +%% is the escape sequence to print a '%' +% followed by an unknown format will print the characters without +trying to do any interpretation + +flag: none + - # (blank) +width: n 0n * +prec: none .0 .n .* +modifier: F N L h l ll z t ('F' and 'N' are ms-dos/16-bit specific) +type: d i o u x X f e g E G c s p n + + +The function needs to allocate memory to store the full text before to +actually writing it. i.e if you want to fnprintf() 1000 characters, the +functions will allocate 1000 bytes. +This behaviour can be modified: you have to customise the code to flush the +internal buffer (writing to screen or file) when it reach a given size. Then +the buffer can have a shorter length. But what? If you really need to write +HUGE string, don't use printf! +During the process, some other memory is allocated (1024 bytes minimum) +to handle the output of partial sprintf() calls. If you have only 10000 bytes +free in memory, you *may* not be able to nprintf() an 8000 bytes-long text. + +note: if a buffer overflow occurs, exit() is called. This situation should +never appear ... but if you want to be *really* sure, you have to modify the +code to handle those situations (only one place to modify). +A buffer overflow can only occur if your sprintf() do strange things or when +you use strange formats. + +*/ +#include "file.h" + +#ifndef lint +FILE_RCSID("@(#)$File: vasprintf.c,v 1.23 2022/09/24 20:30:13 christos Exp $") +#endif /* lint */ + +#include <assert.h> +#include <string.h> +#include <stdlib.h> +#include <stdarg.h> +#include <ctype.h> +#include <limits.h> +#include <stddef.h> + +#define ALLOC_CHUNK 2048 +#define ALLOC_SECURITY_MARGIN 1024 /* big value because some platforms have very big 'G' exponent */ +#if ALLOC_CHUNK < ALLOC_SECURITY_MARGIN +# error !!! ALLOC_CHUNK < ALLOC_SECURITY_MARGIN !!! +#endif +/* note: to have some interest, ALLOC_CHUNK should be much greater than ALLOC_SECURITY_MARGIN */ + +/* + * To save a lot of push/pop, every variable are stored into this + * structure, which is passed among nearly every sub-functions. + */ +typedef struct { + const char * src_string; /* current position into input string */ + char * buffer_base; /* output buffer */ + char * dest_string; /* current position into output string */ + size_t buffer_len; /* length of output buffer */ + size_t real_len; /* real current length of output text */ + size_t pseudo_len; /* total length of output text if it were not limited in size */ + size_t maxlen; + va_list vargs; /* pointer to current position into vargs */ +} xprintf_struct; + +/* + * Realloc buffer if needed + * Return value: 0 = ok + * EOF = not enough memory + */ +static int realloc_buff(xprintf_struct *s, size_t len) +{ + char * ptr; + + if (len + ALLOC_SECURITY_MARGIN + s->real_len > s->buffer_len) { + len += s->real_len + ALLOC_CHUNK; + ptr = (char *)realloc((void *)(s->buffer_base), len); + if (ptr == NULL) { + s->buffer_base = NULL; + return EOF; + } + + s->dest_string = ptr + (size_t)(s->dest_string - s->buffer_base); + s->buffer_base = ptr; + s->buffer_len = len; + + (s->buffer_base)[s->buffer_len - 1] = 1; /* overflow marker */ + } + + return 0; +} + +/* + * Prints 'usual' characters up to next '%' + * or up to end of text + */ +static int usual_char(xprintf_struct * s) +{ + size_t len; + + len = strcspn(s->src_string, "%"); /* reaches the next '%' or end of input string */ + /* note: 'len' is never 0 because the presence of '%' */ + /* or end-of-line is checked in the calling function */ + + if (realloc_buff(s,len) == EOF) + return EOF; + + memcpy(s->dest_string, s->src_string, len); + s->src_string += len; + s->dest_string += len; + s->real_len += len; + s->pseudo_len += len; + + return 0; +} + +/* + * Return value: 0 = ok + * EOF = error + */ +static int print_it(xprintf_struct *s, size_t approx_len, + const char *format_string, ...) +{ + va_list varg; + int vsprintf_len; + size_t len; + + if (realloc_buff(s,approx_len) == EOF) + return EOF; + + va_start(varg, format_string); + vsprintf_len = vsprintf(s->dest_string, format_string, varg); + va_end(varg); + + /* Check for overflow */ + assert((s->buffer_base)[s->buffer_len - 1] == 1); + + if (vsprintf_len == EOF) /* must be done *after* overflow-check */ + return EOF; + + s->pseudo_len += vsprintf_len; + len = strlen(s->dest_string); + s->real_len += len; + s->dest_string += len; + + return 0; +} + +/* + * Prints a string (%s) + * We need special handling because: + * a: the length of the string is unknown + * b: when .prec is used, we must not access any extra byte of the + * string (of course, if the original sprintf() does... what the + * hell, not my problem) + * + * Return value: 0 = ok + * EOF = error + */ +static int type_s(xprintf_struct *s, int width, int prec, + const char *format_string, const char *arg_string) +{ + size_t string_len; + + if (arg_string == NULL) + return print_it(s, (size_t)6, "(null)", 0); + + /* hand-made strlen() which stops when 'prec' is reached. */ + /* if 'prec' is -1 then it is never reached. */ + string_len = 0; + while (arg_string[string_len] != 0 && (size_t)prec != string_len) + string_len++; + + if (width != -1 && string_len < (size_t)width) + string_len = (size_t)width; + + return print_it(s, string_len, format_string, arg_string); +} + +/* + * Read a series of digits. Stop when non-digit is found. + * Return value: the value read (between 0 and 32767). + * Note: no checks are made against overflow. If the string contain a big + * number, then the return value won't be what we want (but, in this case, + * the programmer don't know whatr he wants, then no problem). + */ +static int getint(const char **string) +{ + int i = 0; + + while (isdigit((unsigned char)**string) != 0) { + i = i * 10 + (**string - '0'); + (*string)++; + } + + if (i < 0 || i > 32767) + i = 32767; /* if we have i==-10 this is not because the number is */ + /* negative; this is because the number is big */ + return i; +} + +/* + * Read a part of the format string. A part is 'usual characters' (ie "blabla") + * or '%%' escape sequence (to print a single '%') or any combination of + * format specifier (ie "%i" or "%10.2d"). + * After the current part is managed, the function returns to caller with + * everything ready to manage the following part. + * The caller must ensure than the string is not empty, i.e. the first byte + * is not zero. + * + * Return value: 0 = ok + * EOF = error + */ +static int dispatch(xprintf_struct *s) +{ + const char *initial_ptr; + char format_string[24]; /* max length may be something like "% +-#032768.32768Ld" */ + char *format_ptr; + int flag_plus, flag_minus, flag_space, flag_sharp, flag_zero; + int width, prec, modifier, approx_width; + char type; + /* most of those variables are here to rewrite the format string */ + +#define SRCTXT (s->src_string) +#define DESTTXT (s->dest_string) + + /* incoherent format string. Characters after the '%' will be printed with the next call */ +#define INCOHERENT() do {SRCTXT=initial_ptr; return 0;} while (0) /* do/while to avoid */ +#define INCOHERENT_TEST() do {if(*SRCTXT==0) INCOHERENT();} while (0) /* a null statement */ + + /* 'normal' text */ + if (*SRCTXT != '%') + return usual_char(s); + + /* we then have a '%' */ + SRCTXT++; + /* don't check for end-of-string ; this is done later */ + + /* '%%' escape sequence */ + if (*SRCTXT == '%') { + if (realloc_buff(s, (size_t)1) == EOF) /* because we can have "%%%%%%%%..." */ + return EOF; + *DESTTXT = '%'; + DESTTXT++; + SRCTXT++; + (s->real_len)++; + (s->pseudo_len)++; + return 0; + } + + /* '%' managing */ + initial_ptr = SRCTXT; /* save current pointer in case of incorrect */ + /* 'decoding'. Points just after the '%' so the '%' */ + /* won't be printed in any case, as required. */ + + /* flag */ + flag_plus = flag_minus = flag_space = flag_sharp = flag_zero = 0; + + for (;; SRCTXT++) { + if (*SRCTXT == ' ') + flag_space = 1; + else if (*SRCTXT == '+') + flag_plus = 1; + else if (*SRCTXT == '-') + flag_minus = 1; + else if (*SRCTXT == '#') + flag_sharp = 1; + else if (*SRCTXT == '0') + flag_zero = 1; + else + break; + } + + INCOHERENT_TEST(); /* here is the first test for end of string */ + + /* width */ + if (*SRCTXT == '*') { /* width given by next argument */ + SRCTXT++; + width = va_arg(s->vargs, int); + if ((size_t)width > 0x3fffU) /* 'size_t' to check against negative values too */ + width = 0x3fff; + } else if (isdigit((unsigned char)*SRCTXT)) /* width given as ASCII number */ + width = getint(&SRCTXT); + else + width = -1; /* no width specified */ + + INCOHERENT_TEST(); + + /* .prec */ + if (*SRCTXT == '.') { + SRCTXT++; + if (*SRCTXT == '*') { /* .prec given by next argument */ + SRCTXT++; + prec = va_arg(s->vargs, int); + if ((size_t)prec >= 0x3fffU) /* 'size_t' to check against negative values too */ + prec = 0x3fff; + } else { /* .prec given as ASCII number */ + if (isdigit((unsigned char)*SRCTXT) == 0) + INCOHERENT(); + prec = getint(&SRCTXT); + } + INCOHERENT_TEST(); + } else + prec = -1; /* no .prec specified */ + + /* modifier */ + switch (*SRCTXT) { + case 'L': + case 'h': + case 'l': + case 'z': + case 't': + modifier = *SRCTXT; + SRCTXT++; + if (modifier=='l' && *SRCTXT=='l') { + SRCTXT++; + modifier = 'L'; /* 'll' == 'L' long long == long double */ + } /* only for compatibility ; not portable */ + INCOHERENT_TEST(); + break; + default: + modifier = -1; /* no modifier specified */ + break; + } + + /* type */ + type = *SRCTXT; + if (strchr("diouxXfegEGcspn",type) == NULL) + INCOHERENT(); /* unknown type */ + SRCTXT++; + + /* rewrite format-string */ + format_string[0] = '%'; + format_ptr = &(format_string[1]); + + if (flag_plus) { + *format_ptr = '+'; + format_ptr++; + } + if (flag_minus) { + *format_ptr = '-'; + format_ptr++; + } + if (flag_space) { + *format_ptr = ' '; + format_ptr++; + } + if (flag_sharp) { + *format_ptr = '#'; + format_ptr++; + } + if (flag_zero) { + *format_ptr = '0'; + format_ptr++; + } /* '0' *must* be the last one */ + + if (width != -1) { + sprintf(format_ptr, "%i", width); + format_ptr += strlen(format_ptr); + } + + if (prec != -1) { + *format_ptr = '.'; + format_ptr++; + sprintf(format_ptr, "%i", prec); + format_ptr += strlen(format_ptr); + } + + if (modifier != -1) { + if (modifier == 'L' && strchr("diouxX",type) != NULL) { + *format_ptr = 'l'; + format_ptr++; + *format_ptr = 'l'; + format_ptr++; + } else { + *format_ptr = modifier; + format_ptr++; + } + } + + *format_ptr = type; + format_ptr++; + *format_ptr = 0; + + /* vague approximation of minimal length if width or prec are specified */ + approx_width = width + prec; + if (approx_width < 0) /* because width == -1 and/or prec == -1 */ + approx_width = 0; + + switch (type) { + /* int */ + case 'd': + case 'i': + case 'o': + case 'u': + case 'x': + case 'X': + switch (modifier) { + case -1 : + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); + case 'L': + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long long int)); + case 'l': + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long int)); + case 'h': + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); + case 'z': + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, size_t)); + case 't': + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, ptrdiff_t)); + /* 'int' instead of 'short int' because default promotion is 'int' */ + default: + INCOHERENT(); + } + + /* char */ + case 'c': + if (modifier != -1) + INCOHERENT(); + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); + /* 'int' instead of 'char' because default promotion is 'int' */ + + /* math */ + case 'e': + case 'f': + case 'g': + case 'E': + case 'G': + switch (modifier) { + case -1 : /* because of default promotion, no modifier means 'l' */ + case 'l': + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, double)); + case 'L': + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long double)); + default: + INCOHERENT(); + } + + /* string */ + case 's': + return type_s(s, width, prec, format_string, va_arg(s->vargs, const char*)); + + /* pointer */ + case 'p': + if (modifier == -1) + return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, void *)); + INCOHERENT(); + + /* store */ + case 'n': + if (modifier == -1) { + int * p; + p = va_arg(s->vargs, int *); + if (p != NULL) { + *p = s->pseudo_len; + return 0; + } + return EOF; + } + INCOHERENT(); + + } /* switch */ + + INCOHERENT(); /* unknown type */ + +#undef INCOHERENT +#undef INCOHERENT_TEST +#undef SRCTXT +#undef DESTTXT +} + +/* + * Return value: number of *virtually* written characters + * EOF = error + */ +static int core(xprintf_struct *s) +{ + size_t save_len; + char *dummy_base; + + /* basic checks */ + if ((int)(s->maxlen) <= 0) /* 'int' to check against some conversion */ + return EOF; /* error for example if value is (int)-10 */ + s->maxlen--; /* because initial maxlen counts final 0 */ + /* note: now 'maxlen' _can_ be zero */ + + if (s->src_string == NULL) + s->src_string = "(null)"; + + /* struct init and memory allocation */ + s->buffer_base = NULL; + s->buffer_len = 0; + s->real_len = 0; + s->pseudo_len = 0; + if (realloc_buff(s, (size_t)0) == EOF) + return EOF; + s->dest_string = s->buffer_base; + + /* process source string */ + for (;;) { + /* up to end of source string */ + if (*(s->src_string) == 0) { + *(s->dest_string) = '\0'; /* final NUL */ + break; + } + + if (dispatch(s) == EOF) + goto free_EOF; + + /* up to end of dest string */ + if (s->real_len >= s->maxlen) { + (s->buffer_base)[s->maxlen] = '\0'; /* final NUL */ + break; + } + } + + /* for (v)asnprintf */ + dummy_base = s->buffer_base + s->real_len; + save_len = s->real_len; + + /* process the remaining of source string to compute 'pseudo_len'. We + * overwrite again and again, starting at 'dummy_base' because we don't + * need the text, only char count. */ + while(*(s->src_string) != 0) { /* up to end of source string */ + s->real_len = 0; + s->dest_string = dummy_base; + if (dispatch(s) == EOF) + goto free_EOF; + } + + s->buffer_base = (char *)realloc((void *)(s->buffer_base), save_len + 1); + if (s->buffer_base == NULL) + return EOF; /* should rarely happen because we shrink the buffer */ + return s->pseudo_len; + + free_EOF: + free(s->buffer_base); + return EOF; +} + +int vasprintf(char **ptr, const char *format_string, va_list vargs) +{ + xprintf_struct s; + int retval; + + memset(&s, 0, sizeof(s)); + s.src_string = format_string; +#ifdef va_copy + va_copy (s.vargs, vargs); +#else +# ifdef __va_copy + __va_copy (s.vargs, vargs); +# else +# ifdef WIN32 + s.vargs = vargs; +# else + memcpy (&s.vargs, &vargs, sizeof (s.vargs)); +# endif /* WIN32 */ +# endif /* __va_copy */ +#endif /* va_copy */ + s.maxlen = (size_t)INT_MAX; + + retval = core(&s); + va_end(s.vargs); + if (retval == EOF) { + *ptr = NULL; + return EOF; + } + + *ptr = s.buffer_base; + return retval; +} |