compat/regex: move stdlib.h up in inclusion chain

sgn · gitster · commit 3bc1f9e48cb9 · 2020-04-27T11:21:16.000-07:00
In Linux with musl libc, we have this inclusion chain:

compat/regex/regex.c:69
`-&gt; compat/regex/regex_internal.h
   `-&gt; /usr/include/stdlib.h
      `-&gt; /usr/include/features.h
      `-&gt; /usr/include/alloca.h

In that inclusion chain, `&lt;features.h&gt;` claims it's _BSD_SOURCE
compatible when it's NOT asked to be either
{_POSIX,_GNU,_XOPEN,_BSD}_SOURCE, or __STRICT_ANSI__.
And, `&lt;stdlib.h&gt;` will include `&lt;alloca.h&gt;` 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 `&lt;stdlib.h&gt;` early to prevent the redefinition of alloca.
This also remove a potential warning about alloca not defined on:
	#undef alloca

Helped-by: Ramsay Jones &lt;ramsay@ramsayjones.plus.com&gt;
Signed-off-by: Đoàn Trần Công Danh &lt;congdanhqx@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git 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
@@ -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
