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Re: [PATCH v5 6/8] Introduce a new data type for timestamps

From
René Scharfe <l.s.r@web.de>
Date
Apr 26, 2017, 22:32 UTC
Message-ID
<615c74de-0a9d-b5ff-f7f2-68feca5d1985@web.de>
In-Reply-To
<fea2df0e1ff5869572cf756d75fd3468d184457f.1493042239.git.johannes.schindelin@gmx.de>
Am 24.04.2017 um 15:58 schrieb Johannes Schindelin:
Show 55 quoted lines
> diff --git a/archive-tar.c b/archive-tar.c
> index 380e3aedd23..695339a2369 100644
> --- a/archive-tar.c
> +++ b/archive-tar.c
> @@ -27,9 +27,12 @@ static int write_tar_filter_archive(const struct archiver *ar,
>    */
>   #if ULONG_MAX == 0xFFFFFFFF
>   #define USTAR_MAX_SIZE ULONG_MAX
> -#define USTAR_MAX_MTIME ULONG_MAX
>   #else
>   #define USTAR_MAX_SIZE 077777777777UL
> +#endif
> +#if TIME_MAX == 0xFFFFFFFF
> +#define USTAR_MAX_MTIME TIME_MAX
> +#else
>   #define USTAR_MAX_MTIME 077777777777UL
>   #endif
>   
> diff --git a/archive-zip.c b/archive-zip.c
> index b429a8d974a..68df3d64402 100644
> --- a/archive-zip.c
> +++ b/archive-zip.c
> @@ -545,9 +545,17 @@ static void write_zip_trailer(const unsigned char *sha1)
>   		write_or_die(1, sha1_to_hex(sha1), GIT_SHA1_HEXSZ);
>   }
>   
> -static void dos_time(time_t *time, int *dos_date, int *dos_time)
> +static void dos_time(timestamp_t *timestamp, int *dos_date, int *dos_time)
>   {
> -	struct tm *t = localtime(time);
> +	time_t time;
> +	struct tm *t;
> +
> +	if (date_overflows(*timestamp))
> +		die("timestamp too large for this system: %"PRItime,
> +		    *timestamp);
> +	time = (time_t)*timestamp;
> +	t = localtime(&time);
> +	*timestamp = time;
>   
>   	*dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
>   	            (t->tm_year + 1900 - 1980) * 512;
> diff --git a/archive.h b/archive.h
> index 415e0152e2c..62d1d82c1af 100644
> --- a/archive.h
> +++ b/archive.h
> @@ -9,7 +9,7 @@ struct archiver_args {
>   	struct tree *tree;
>   	const unsigned char *commit_sha1;
>   	const struct commit *commit;
> -	time_t time;
> +	timestamp_t time;
>   	struct pathspec pathspec;
>   	unsigned int verbose : 1;
>   	unsigned int worktree_attributes : 1;
time_t is converted to timestamp_t here.  Hmm.

Truncation can already occur in archive.c::parse_treeish_arg() when assigning commit->date (of type timestamp_t) to archive_time (of type time_t). The overflow check should either be moved there or the type of the latter variable should be changed, right?

Compilation and tests are still successful on Debian x86 and MinGW64 even after removing the changes above. On the former the test "generate tar with future mtime" in t5000 writes Epoch time stamps in both cases (and doesn't notice because tar is unable to handle times after 2038, so that check is skipped), on the latter it emits the correct future dates.

So what are the benefits of these changes?

Unless I'm missing something (very possible at this time of day) I'd say drop these hunks and let me handle the fallout of the series in archive. I was planning on improving its date handling code anyway (eventually)..

René
Previous: Johannes SchindelinNext: Johannes Schindelin
Message 94 of 113 in “Use time_t”
  1. 0/6 Use time_tJohannes Schindelin, Feb 27, 2017
  2. 5/6 ref-filter: avoid using `unsigned long` for catch-all data typeJohannes Schindelin, Feb 27, 2017
  3. 4/6 Prepare for timestamps to use 64-bit signed typesJohannes Schindelin, Feb 27, 2017
  4. 3/6 Introduce a new "printf format" for timestampsJohannes Schindelin, Feb 27, 2017
  5. Junio C HamanoMar 1, 2017
  6. Junio C HamanoMar 1, 2017
  7. 2/6 Specify explicitly where we parse timestampsJohannes Schindelin, Feb 27, 2017
  8. Junio C HamanoFeb 27, 2017
  9. Junio C HamanoFeb 27, 2017
  10. Johannes SchindelinFeb 28, 2017
  11. 1/6 t0006 & t5000: prepare for 64-bit time_tJohannes Schindelin, Feb 27, 2017
  12. Junio C HamanoFeb 27, 2017
  13. 6/6 Use time_t where appropriateJohannes Schindelin, Feb 27, 2017
  14. Junio C HamanoFeb 27, 2017
  15. Johannes SchindelinFeb 28, 2017
  16. Jeff KingFeb 28, 2017
  17. Johannes SchindelinFeb 28, 2017
  18. René ScharfeFeb 28, 2017
  19. Junio C HamanoFeb 28, 2017
  20. Jeff KingFeb 28, 2017
  21. Johannes SchindelinFeb 28, 2017
  22. Jeff KingFeb 28, 2017
  23. René ScharfeFeb 28, 2017
  24. Johannes SchindelinFeb 28, 2017
  25. René ScharfeMar 1, 2017
  26. Junio C HamanoFeb 28, 2017
  27. Jeff KingFeb 28, 2017
  28. Junio C HamanoFeb 28, 2017
  29. Jeff KingFeb 28, 2017
  30. Junio C HamanoMar 1, 2017
  31. 0/8 Introduce timestamp_t for timestampsJohannes Schindelin, Apr 2, 2017
  32. 1/8 ref-filter: avoid using `unsigned long` for catch-all data typeJohannes Schindelin, Apr 2, 2017
  33. Torsten BögershausenApr 3, 2017
  34. Johannes SchindelinApr 3, 2017
  35. 2/8 t0006 & t5000: prepare for 64-bit timestampsJohannes Schindelin, Apr 2, 2017
  36. 3/8 t0006 & t5000: skip "far in the future" test when time_t is too limitedJohannes Schindelin, Apr 2, 2017
  37. 4/8 Specify explicitly where we parse timestampsJohannes Schindelin, Apr 2, 2017
  38. Torsten BögershausenApr 3, 2017
  39. Johannes SchindelinApr 3, 2017
  40. 5/8 Introduce a new "printf format" for timestampsJohannes Schindelin, Apr 2, 2017
  41. 6/8 Introduce a new data type for timestampsJohannes Schindelin, Apr 2, 2017
  42. 7/8 Abort if the system time cannot handle one of our timestampsJohannes Schindelin, Apr 2, 2017
  43. 8/8 Use uintmax_t for timestampsJohannes Schindelin, Apr 2, 2017
  44. 0/8 Introduce timestamp_t for timestampsJohannes Schindelin, Apr 20, 2017
  45. 1/8 ref-filter: avoid using `unsigned long` for catch-all data typeJohannes Schindelin, Apr 20, 2017
  46. 2/8 t0006 & t5000: prepare for 64-bit timestampsJohannes Schindelin, Apr 20, 2017
  47. 3/8 t0006 & t5000: skip "far in the future" test when time_t is too limitedJohannes Schindelin, Apr 20, 2017
  48. 4/8 Specify explicitly where we parse timestampsJohannes Schindelin, Apr 20, 2017
  49. 5/8 Introduce a new "printf format" for timestampsJohannes Schindelin, Apr 20, 2017
  50. 6/8 Introduce a new data type for timestampsJohannes Schindelin, Apr 20, 2017
  51. 8/8 Use uintmax_t for timestampsJohannes Schindelin, Apr 20, 2017
  52. 7/8 Abort if the system time cannot handle one of our timestampsJohannes Schindelin, Apr 20, 2017
  53. Junio C HamanoApr 21, 2017
  54. Johannes SchindelinApr 21, 2017
  55. 0/9 Introduce timestamp_t for timestampsJohannes Schindelin, Apr 21, 2017
  56. 1/9 ref-filter: avoid using `unsigned long` for catch-all data typeJohannes Schindelin, Apr 21, 2017
  57. 2/9 t0006 & t5000: prepare for 64-bit timestampsJohannes Schindelin, Apr 21, 2017
  58. 3/9 t0006 & t5000: skip "far in the future" test when time_t is too limitedJohannes Schindelin, Apr 21, 2017
  59. 4/9 Specify explicitly where we parse timestampsJohannes Schindelin, Apr 21, 2017
  60. Junio C HamanoApr 24, 2017
  61. 5/9 Introduce a new "printf format" for timestampsJohannes Schindelin, Apr 21, 2017
  62. 6/9 Introduce a new data type for timestampsJohannes Schindelin, Apr 21, 2017
  63. 7/9 Abort if the system time cannot handle one of our timestampsJohannes Schindelin, Apr 21, 2017
  64. Junio C HamanoApr 24, 2017
  65. Johannes SchindelinApr 24, 2017
  66. Junio C HamanoApr 25, 2017
  67. Junio C HamanoApr 25, 2017
  68. 8/9 Use uintmax_t for timestampsJohannes Schindelin, Apr 21, 2017
  69. Junio C HamanoApr 24, 2017
  70. Johannes SchindelinApr 24, 2017
  71. Junio C HamanoApr 25, 2017
  72. Johannes SchindelinApr 25, 2017
  73. Junio C HamanoApr 26, 2017
  74. Junio C HamanoApr 26, 2017
  75. Johannes SchindelinApr 26, 2017
  76. Junio C HamanoApr 26, 2017
  77. 9/9 show_date_ident(): defer date overflow checkJohannes Schindelin, Apr 21, 2017
  78. Junio C HamanoApr 24, 2017
  79. Jacob KellerApr 24, 2017
  80. Johannes SchindelinApr 24, 2017
  81. Jeff KingApr 24, 2017
  82. Johannes SchindelinApr 25, 2017
  83. Johannes SchindelinApr 24, 2017
  84. 0/8 Introduce timestamp_t for timestampsJohannes Schindelin, Apr 24, 2017
  85. 1/8 ref-filter: avoid using `unsigned long` for catch-all data typeJohannes Schindelin, Apr 24, 2017
  86. 2/8 t0006 & t5000: prepare for 64-bit timestampsJohannes Schindelin, Apr 24, 2017
  87. 3/8 t0006 & t5000: skip "far in the future" test when time_t is too limitedJohannes Schindelin, Apr 24, 2017
  88. 5/8 Introduce a new "printf format" for timestampsJohannes Schindelin, Apr 24, 2017
  89. 4/8 Specify explicitly where we parse timestampsJohannes Schindelin, Apr 24, 2017
  90. Junio C HamanoApr 25, 2017
  91. 6/8 Introduce a new data type for timestampsJohannes Schindelin, Apr 24, 2017
  92. Johannes SixtApr 26, 2017
  93. Johannes SchindelinApr 26, 2017
  94. René ScharfeApr 26, 2017
  95. 7/8 Abort if the system time cannot handle one of our timestampsJohannes Schindelin, Apr 24, 2017
  96. 8/8 Use uintmax_t for timestampsJohannes Schindelin, Apr 24, 2017
  97. Johannes SixtApr 26, 2017
  98. Johannes SchindelinApr 26, 2017
  99. René ScharfeApr 25, 2017
  100. Johannes SchindelinApr 25, 2017
  101. René ScharfeApr 26, 2017
  102. Junio C HamanoApr 26, 2017
  103. 0/8 Introduce timestamp_t for timestampsJohannes Schindelin, Apr 26, 2017
  104. 1/8 ref-filter: avoid using `unsigned long` for catch-all data typeJohannes Schindelin, Apr 26, 2017
  105. 2/8 t0006 & t5000: prepare for 64-bit timestampsJohannes Schindelin, Apr 26, 2017
  106. 3/8 t0006 & t5000: skip "far in the future" test when time_t is too limitedJohannes Schindelin, Apr 26, 2017
  107. 4/8 Specify explicitly where we parse timestampsJohannes Schindelin, Apr 26, 2017
  108. 5/8 Introduce a new "printf format" for timestampsJohannes Schindelin, Apr 26, 2017
  109. 6/8 Introduce a new data type for timestampsJohannes Schindelin, Apr 26, 2017
  110. name-rev: change a "long" variable to timestamp_tJunio C Hamano, May 20, 2017
  111. Johannes SchindelinMay 22, 2017
  112. 7/8 Abort if the system time cannot handle one of our timestampsJohannes Schindelin, Apr 26, 2017
  113. 8/8 Use uintmax_t for timestampsJohannes Schindelin, Apr 26, 2017

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