diff options
| author | Darren Tucker <dtucker@dtucker.net> | 2018-02-25 10:20:31 +1100 |
|---|---|---|
| committer | Darren Tucker <dtucker@dtucker.net> | 2018-02-26 00:09:04 +1100 |
| commit | e9dede06e5bc582a4aeb5b1cd5a7a640d7de3609 (patch) | |
| tree | f149ff2fb7ff3d427cfd1e7fcee416e7922ada84 | |
| parent | 2eb4041493fd2635ffdc64a852d02b38c4955e0b (diff) | |
Handle calloc(0,x) where different from malloc.
Configure assumes that if malloc(0) returns null then calloc(0,n)
also does. On some old platforms (SunOS4) malloc behaves as expected
(as determined by AC_FUNC_MALLOC) but calloc doesn't. Test for this
at configure time and activate the replacement function if found, plus
handle this case in rpl_calloc.
| -rw-r--r-- | configure.ac | 19 | ||||
| -rw-r--r-- | openbsd-compat/bsd-malloc.c | 2 |
2 files changed, 19 insertions, 2 deletions
diff --git a/configure.ac b/configure.ac index 03cc3f86..605844ba 100644 --- a/configure.ac +++ b/configure.ac @@ -1337,8 +1337,23 @@ AC_FUNC_STRFTIME AC_FUNC_MALLOC AC_FUNC_REALLOC # autoconf doesn't have AC_FUNC_CALLOC so fake it if malloc returns NULL; -if test "x$ac_cv_func_malloc_0_nonnull" != "xyes"; then - AC_DEFINE(HAVE_CALLOC, 0, [calloc(x, 0) returns NULL]) +AC_MSG_CHECKING([if calloc(0, N) returns non-null]) +AC_RUN_IFELSE( + [AC_LANG_PROGRAM( + [[ #include <stdlib.h> ]], + [[ void *p = calloc(0, 1); exit(p == NULL); ]] + )], + [ func_calloc_0_nonnull=yes ], + [ func_calloc_0_nonnull=no ], + [ AC_MSG_WARN([cross compiling: assuming same as malloc]) + func_calloc_0_nonnull="$ac_cv_func_malloc_0_nonnull"] +) +AC_MSG_RESULT([$func_calloc_0_nonnull]) + +if test "x$func_calloc_0_nonnull" == "xyes"; then + AC_DEFINE(HAVE_CALLOC, 1, [calloc(0, x) returns non-null]) +else + AC_DEFINE(HAVE_CALLOC, 0, [calloc(0, x) returns NULL]) AC_DEFINE(calloc, rpl_calloc, [Define to rpl_calloc if the replacement function should be used.]) fi diff --git a/openbsd-compat/bsd-malloc.c b/openbsd-compat/bsd-malloc.c index 6402ab58..482facdc 100644 --- a/openbsd-compat/bsd-malloc.c +++ b/openbsd-compat/bsd-malloc.c @@ -50,6 +50,8 @@ rpl_realloc(void *ptr, size_t size) { if (size == 0) size = 1; + if (ptr == 0) + return malloc(size); return realloc(ptr, size); } #endif |