From: Paul Eggert Date: Sun, 27 Jan 2013 16:41:32 +0000 (-0800) Subject: tar: improve quality of diagnostics with incrementals X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Ftar;a=commitdiff_plain;h=9cf743abf8667ae07077ceb32fad9a94268a5a93 tar: improve quality of diagnostics with incrementals Inspired by a prototype by Nathan Stratton Treadway in . * src/incremen.c (read_num): Rewrite by merging read_negative_num and read_unsigned_num. Use strtosysint rather than rolling this stuff ourselves. Change return type to bool. All uses changed. (read_negative_num, read_unsigned_num): Remove. (read_num, read_timespec, read_incr_db_2): Improve quality of diagnostics, e.g., by supplying byte offset of error. --- diff --git a/src/incremen.c b/src/incremen.c index 7130bc2..1d20c44 100644 --- a/src/incremen.c +++ b/src/incremen.c @@ -1079,106 +1079,84 @@ read_obstack (FILE *fp, struct obstack *stk, size_t *pcount) return c; } -/* Read from file FP a nul-terminated string and convert it to - intmax_t. Return the resulting value in PVAL. Assume '-' has - already been read. +/* Read from file FP a null-terminated string and convert it to an + integer. FIELDNAME is the intended use of the integer, useful for + diagnostics. MIN_VAL and MAX_VAL are its minimum and maximum + permissible values; MIN_VAL must be nonpositive and MAX_VAL positive. + Store into *PVAL the resulting value, converted to intmax_t. Throw a fatal error if the string cannot be converted or if the - converted value is less than MIN_VAL. */ + converted value is out of range. -static void -read_negative_num (FILE *fp, intmax_t min_val, intmax_t *pval) + Return true if successful, false if end of file. */ + +static bool +read_num (FILE *fp, char const *fieldname, + intmax_t min_val, uintmax_t max_val, intmax_t *pval) { - int c; - size_t i; + int i; char buf[INT_BUFSIZE_BOUND (intmax_t)]; - char *ep; - buf[0] = '-'; + char offbuf[INT_BUFSIZE_BOUND (off_t)]; + char minbuf[INT_BUFSIZE_BOUND (intmax_t)]; + char maxbuf[INT_BUFSIZE_BOUND (intmax_t)]; + int conversion_errno; + int c = getc (fp); + bool negative = c == '-'; - for (i = 1; ISDIGIT (c = getc (fp)); i++) + for (i = 0; (i == 0 && negative) || ISDIGIT (c); i++) { - if (i == sizeof buf - 1) - FATAL_ERROR ((0, 0, _("Field too long while reading snapshot file"))); buf[i] = c; - } - - if (c < 0) - { - if (ferror (fp)) - FATAL_ERROR ((0, errno, _("Read error in snapshot file"))); - else - FATAL_ERROR ((0, 0, _("Unexpected EOF in snapshot file"))); - } - - buf[i] = 0; - errno = 0; - *pval = strtoimax (buf, &ep, 10); - if (c || errno || *pval < min_val) - FATAL_ERROR ((0, errno, _("Unexpected field value in snapshot file"))); -} - -/* Read from file FP a nul-terminated string and convert it to - uintmax_t. Return an intmax_t representation of the resulting - value in PVAL. Assume C has already been read. - - Throw a fatal error if the string cannot be converted or if the - converted value exceeds MAX_VAL. - - Return the last character read or EOF on end of file. */ - -static int -read_unsigned_num (int c, FILE *fp, uintmax_t max_val, intmax_t *pval) -{ - size_t i; - uintmax_t u; - char buf[UINTMAX_STRSIZE_BOUND], *ep; - - for (i = 0; ISDIGIT (c); i++) - { if (i == sizeof buf - 1) - FATAL_ERROR ((0, 0, _("Field too long while reading snapshot file"))); - buf[i] = c; + FATAL_ERROR ((0, 0, + _("%s: byte %s: %s %.*s... too long"), + quotearg_colon (listed_incremental_option), + offtostr (ftello (fp), offbuf), + fieldname, i + 1, buf)); c = getc (fp); } + buf[i] = 0; + if (c < 0) { if (ferror (fp)) - FATAL_ERROR ((0, errno, _("Read error in snapshot file"))); - else if (i == 0) - return c; - else - FATAL_ERROR ((0, 0, _("Unexpected EOF in snapshot file"))); + read_fatal (listed_incremental_option); + if (i != 0) + FATAL_ERROR ((0, 0, "%s: %s", + quotearg_colon (listed_incremental_option), + _("Unexpected EOF in snapshot file"))); + return false; } - buf[i] = 0; - errno = 0; - u = strtoumax (buf, &ep, 10); - if (c || errno || max_val < u) - FATAL_ERROR ((0, errno, _("Unexpected field value in snapshot file"))); - *pval = represent_uintmax (u); - return c; -} - -/* Read from file FP a nul-terminated string and convert it to - an integer in the range MIN_VAL..MAXVAL. Return the resulting - value, converted to intmax_t, in PVAL. MINVAL must be nonpositive. - - Throw a fatal error if the string cannot be converted or if the - converted value is out of range. + if (c) + FATAL_ERROR ((0, 0, + _("%s: byte %s: %s %s followed by invalid byte 0x%02x"), + quotearg_colon (listed_incremental_option), + offtostr (ftello (fp), offbuf), + fieldname, buf, c)); - Return the last character read or EOF on end of file. */ + *pval = strtosysint (buf, NULL, min_val, max_val); + conversion_errno = errno; -static int -read_num (FILE *fp, intmax_t min_val, uintmax_t max_val, intmax_t *pval) -{ - int c = getc (fp); - if (c == '-') + switch (conversion_errno) { - read_negative_num (fp, min_val, pval); - return 0; + case ERANGE: + FATAL_ERROR ((0, conversion_errno, + _("%s: byte %s: (valid range %s..%s)\n\t%s %s"), + quotearg_colon (listed_incremental_option), + offtostr (ftello (fp), offbuf), + imaxtostr (min_val, minbuf), + umaxtostr (max_val, maxbuf), fieldname, buf)); + default: + FATAL_ERROR ((0, conversion_errno, + _("%s: byte %s: %s %s"), + quotearg_colon (listed_incremental_option), + offtostr (ftello (fp), offbuf), fieldname, buf)); + case 0: + break; } - return read_unsigned_num (c, fp, max_val, pval); + + return true; } /* Read from FP two NUL-terminated strings representing a struct @@ -1189,15 +1167,20 @@ read_num (FILE *fp, intmax_t min_val, uintmax_t max_val, intmax_t *pval) static void read_timespec (FILE *fp, struct timespec *pval) { - intmax_t i; - int c = read_num (fp, TYPE_MINIMUM (time_t), TYPE_MAXIMUM (time_t), &i); - pval->tv_sec = i; + intmax_t s, ns; - if (c || read_num (fp, 0, BILLION - 1, &i)) - FATAL_ERROR ((0, 0, "%s: %s", - quotearg_colon (listed_incremental_option), - _("Unexpected EOF in snapshot file"))); - pval->tv_nsec = i; + if (read_num (fp, "sec", TYPE_MINIMUM (time_t), TYPE_MAXIMUM (time_t), &s) + && read_num (fp, "nsec", 0, BILLION - 1, &ns)) + { + pval->tv_sec = s; + pval->tv_nsec = ns; + } + else + { + FATAL_ERROR ((0, 0, "%s: %s", + quotearg_colon (listed_incremental_option), + _("Unexpected EOF in snapshot file"))); + } } /* Read incremental snapshot format 2 */ @@ -1205,6 +1188,7 @@ static void read_incr_db_2 (void) { struct obstack stk; + char offbuf[INT_BUFSIZE_BOUND (off_t)]; obstack_init (&stk); @@ -1221,20 +1205,20 @@ read_incr_db_2 (void) char *content; size_t s; - if (read_num (listed_incremental_stream, 0, 1, &i)) + if (! read_num (listed_incremental_stream, "nfs", 0, 1, &i)) return; /* Normal return */ nfs = i; read_timespec (listed_incremental_stream, &mtime); - if (read_num (listed_incremental_stream, - TYPE_MINIMUM (dev_t), TYPE_MAXIMUM (dev_t), &i)) + if (! read_num (listed_incremental_stream, "dev", + TYPE_MINIMUM (dev_t), TYPE_MAXIMUM (dev_t), &i)) break; dev = i; - if (read_num (listed_incremental_stream, - TYPE_MINIMUM (ino_t), TYPE_MAXIMUM (ino_t), &i)) + if (! read_num (listed_incremental_stream, "ino", + TYPE_MINIMUM (ino_t), TYPE_MAXIMUM (ino_t), &i)) break; ino = i; @@ -1246,8 +1230,9 @@ read_incr_db_2 (void) while (read_obstack (listed_incremental_stream, &stk, &s) == 0 && s > 1) ; if (getc (listed_incremental_stream) != 0) - FATAL_ERROR ((0, 0, "%s: %s", + FATAL_ERROR ((0, 0, _("%s: byte %s: %s"), quotearg_colon (listed_incremental_option), + offtostr (ftello (listed_incremental_stream), offbuf), _("Missing record terminator"))); content = obstack_finish (&stk);