In Linux with musl libc, we have this inclusion chain: compat/regex/regex.c:69 `-> compat/regex/regex_internal.h `-> /usr/include/stdlib.h `-> /usr/include/features.h `-> /usr/include/alloca.h In that inclusion chain, `<features.h>` claims it's _BSD_SOURCE compatible when it's NOT asked to be either {_POSIX,_GNU,_XOPEN,_BSD}_SOURCE, or __STRICT_ANSI__. And, `<stdlib.h>` will include `<alloca.h>` to be compatible with software written for GNU and BSD. Thus, redefine `alloca` macro, which was defined before at compat/regex/regex.c:66. Considering this is only compat code, we've taken from other project, it's not our business to decide which source should we adhere to. Include `<stdlib.h>` early to prevent the redefinition of alloca. This also remove a potential warning about alloca not defined on: #undef alloca Helped-by: Ramsay Jones <ramsay@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Đoàn Trần Công Danh <congdanhqx@xxxxxxxxx> --- Notes: There is another warning about un-match declaration and definition of re_string_context_at. It's arguably, a bug in sparse itself. Consider that there's a fix for it in their development version already, and, we expect they'll fix the zero-ing pattern in 1/? before enable it again. There're no point to change that pair of declaration/definition. This patch is technically Ramsay's work. Since <alloca.h> is likely unportable, my patch will be likely unusable. I took Ramsay's work and write the commit message instead. I would love to see Ramsay's SoB on reply to this patch. compat/regex/regex.c | 1 + compat/regex/regex_internal.h | 1 - 2 files changed, 1 insertion(+), 1 deletion(-) diff --git a/compat/regex/regex.c b/compat/regex/regex.c index f3e03a9eab..e6f4a5d177 100644 --- a/compat/regex/regex.c +++ b/compat/regex/regex.c @@ -60,6 +60,7 @@ #undefs RE_DUP_MAX and sets it to the right value. */ #include <limits.h> #include <stdint.h> +#include <stdlib.h> #ifdef GAWK #undef alloca diff --git a/compat/regex/regex_internal.h b/compat/regex/regex_internal.h index 3ee8aae59d..0bad8b841e 100644 --- a/compat/regex/regex_internal.h +++ b/compat/regex/regex_internal.h @@ -23,7 +23,6 @@ #include <assert.h> #include <ctype.h> #include <stdio.h> -#include <stdlib.h> #include <string.h> #if defined HAVE_LANGINFO_H || defined HAVE_LANGINFO_CODESET || defined _LIBC -- 2.26.2.526.g744177e7f7