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Re: [PATCH 01/14] Fix non-constant array creation

From
Junio C Hamano <gitster@pobox.com>
Date
Aug 21, 2009, 20:39 UTC
Message-ID
<7vws4wdhq8.fsf@alter.siamese.dyndns.org>
In-Reply-To
<6283b3e1775f43c6fc07e5047f9c99acdc27bc8f.1250860247.git.mstormo@gmail.com>
Marius Storm-Olsen <mstormo@gmail.com> writes:
> MSVC doesn't munge the non-constant expression, so use xmalloc instead.
Thanks.

These things are called variable length array, and MSVC is not the only one that do not glok vla.

	Subject: Avoid use of variable length array
        Some compilers unfortunately do not understand these constructs.
	In codepaths that are not performance critical, use xmalloc()
        and free() instead.

There is another use of vla; I would suggest squashing the following patch in.

diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index c433748..5065abd 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -1599,7 +1599,7 @@ static void *threaded_find_deltas(void *arg)
 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
 			   int window, int depth, unsigned *processed)
 {
-	struct thread_params p[delta_search_threads];
+	struct thread_params *p;
 	int i, ret, active_threads = 0;
 
 	if (delta_search_threads <= 1) {
@@ -1610,6 +1610,8 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
 		fprintf(stderr, "Delta compression using up to %d threads.\n",
 				delta_search_threads);
 
+	p = xcalloc(delta_search_threads, sizeof(*p));
+
 	/* Partition the work amongst work threads. */
 	for (i = 0; i < delta_search_threads; i++) {
 		unsigned sub_size = list_size / (delta_search_threads - i);
@@ -1717,6 +1719,8 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
 			active_threads--;
 		}
 	}
+
+	free(p);
 }
 
 #else
Previous: Junio C Hamano
Message 49 of 49 in “Build git with MSVC”
  1. 00/14 Build git with MSVCMarius Storm-Olsen, Aug 21, 2009
  2. 01/14 Fix non-constant array creationMarius Storm-Olsen, Aug 21, 2009
  3. 02/14 Avoid declaration after statementMarius Storm-Olsen, Aug 21, 2009
  4. 03/14 Define SNPRINTF_SIZE_CORR=1 for Microsoft Visual C++Marius Storm-Olsen, Aug 21, 2009
  5. 04/14 Add define guards to compat/win32.hMarius Storm-Olsen, Aug 21, 2009
  6. 05/14 Change regerror() declaration from K&R style to ANSI C (C89)Marius Storm-Olsen, Aug 21, 2009
  7. 06/14 mingw.c: Use the O_BINARY flag to open filesMarius Storm-Olsen, Aug 21, 2009
  8. 07/14 Fix __stdcall/WINAPI placement and function prototypeMarius Storm-Olsen, Aug 21, 2009
  9. 08/14 Test for WIN32 instead of __MINGW32_Marius Storm-Olsen, Aug 21, 2009
  10. 09/14 Avoid including windows.h in winansi.c for MSVC buildMarius Storm-Olsen, Aug 21, 2009
  11. 10/14 Add empty header files for MSVC portMarius Storm-Olsen, Aug 21, 2009
  12. 11/14 Add MinGW header files to build git with MSVCMarius Storm-Olsen, Aug 21, 2009
  13. 12/14 Add platform files for MSVC portingMarius Storm-Olsen, Aug 21, 2009
  14. 13/14 Add MSVC project filesMarius Storm-Olsen, Aug 21, 2009
  15. 14/14 Add README and gitignore file for MSVC buildMarius Storm-Olsen, Aug 21, 2009
  16. Thiago FarinaAug 23, 2009
  17. Reece DunnAug 23, 2009
  18. Marius Storm-OlsenAug 23, 2009
  19. Thiago FarinaAug 23, 2009
  20. Marius Storm-OlsenAug 24, 2009
  21. Frank LiAug 25, 2009
  22. Thiago FarinaAug 25, 2009
  23. Frank LiAug 27, 2009
  24. Thiago FarinaAug 27, 2009
  25. Erik Faye-LundSep 7, 2009
  26. Junio C HamanoAug 21, 2009
  27. Reece DunnAug 21, 2009
  28. Marius Storm-OlsenAug 22, 2009
  29. Paolo BonziniAug 28, 2009
  30. Johannes SixtAug 21, 2009
  31. Marius Storm-OlsenAug 21, 2009
  32. Frank LiAug 21, 2009
  33. 05/14 Change regerror() definition from K&R style to ANSI C (C89)Marius Storm-Olsen, Aug 21, 2009
  34. Frank LiAug 22, 2009
  35. Erik Faye-LundAug 24, 2009
  36. Junio C HamanoAug 21, 2009
  37. Johan 't HartAug 21, 2009
  38. Johannes SixtAug 21, 2009
  39. Junio C HamanoAug 21, 2009
  40. Marius Storm-OlsenAug 22, 2009
  41. Marius Storm-OlsenAug 22, 2009
  42. Erik Faye-LundAug 21, 2009
  43. Marius Storm-OlsenAug 21, 2009
  44. Janos LaubeAug 21, 2009
  45. Marius Storm-OlsenAug 21, 2009
  46. Johan 't HartAug 21, 2009
  47. Erik Faye-LundAug 22, 2009
  48. Junio C HamanoAug 21, 2009
  49. Junio C HamanoAug 21, 2009

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