@matheusbsbs / matheus-bagliano / commits / 481df65f4f

git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULL

Add a FREE_AND_NULL() wrapper marco for the common pattern of freeing a pointer and assigning NULL to it right afterwards. The implementation is similar to the (currently unused) XDL_PTRFREE macro in xdiff/xmacros.h added in commit 3443546f6e ("Use a *real* built-in diff generator", 2006-03-24). The only difference is that free() is called unconditionally, see [1]. See [2] for a suggested alternative which does this via a function instead of a macro. As covered in replies to that message, while it's a viable approach, it would introduce caveats which this approach doesn't have, so that potential change is left to a future follow-up change. This merely allows us to translate exactly what we're doing now to a less verbose & idiomatic form using a macro, while guaranteeing that we don't introduce any functional changes. 1. <alpine.DEB.2.20.1608301948310.129229@virtualbox> (http://public-inbox.org/git/alpine.DEB.2.20.1608301948310.129229@virtualbox/) 2. <20170610032143.GA7880@starla> (https://public-inbox.org/git/20170610032143.GA7880@starla/) Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Ævar Arnfjörð Bjarmason committed Jun 15, 2017 at 21:06 UTC 481df65f4f72582369eea8d002070c5dff38f8e6

1 file changed +6

git-compat-util.h

@@ -808,6 +808,12 @@ extern char *xgetcwd(void);

808 extern FILE *fopen_for_writing(const char *path);

809 extern FILE *fopen_or_warn(const char *path, const char *mode);

810

811 +/*

812 + * FREE_AND_NULL(ptr) is like free(ptr) followed by ptr = NULL. Note

813 + * that ptr is used twice, so don't pass e.g. ptr++.

814 + */

815 +#define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)

816 +

817 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))

818 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))

819