Limit <config.h>’s includes

This follows up on recent problems with the fact that config.h
includes stdlib.h etc.; some files need to include stdlib.h later.
config.h generally should limit itself to includes that are
universally safe; outside of MS-Windows, only stdbool.h makes
the cut among the files currently included.  So, move the
other includes to just the files that need them (Bug#24506).
* configure.ac (config_opsysfile): Remove, as this generic hook
is no longer needed.
* lib-src/etags.c, src/unexmacosx.c, src/w32.c, src/w32notify.c:
* src/w32proc.c (_GNU_SOURCE):
Remove, as it’s OK for config.h to do this now.
* src/conf_post.h: Include <ms-w32.h>, instead of the generic
config_opsysfile, for simplicity as this old way of configuring is
now done only for the MS-Windows port.  Do not include <ms-w32.h>
if DEFER_MS_W32_H, for the benefit of the few files that want its
effects later.  Do not include <alloca.h>, <string.h>, or
<stdlib.h>.  Other files modified to include these headers as
needed, or to not include headers that are no longer needed.
* src/lisp.h: Include <alloca.h> and <string.h> here, since
some of the inline functions need them.
* src/regex.c: Include <alloca.h> if not emacs.  (If emacs,
we can rely on SAFE_ALLOCA.)  There is no longer any need to
worry about HAVE_ALLOCA_H.
* src/unexmacosx.c: Rely on config.h not including stdlib.h.
* src/w32.c, src/w32notify.c, src/w32proc.c (DEFER_MS_W32_H):
Define before including <config.h> first, and include <ms-w32.h>
after the troublesome headers.

1 files changed, 2 insertions, 14 deletions

diff --git a/src/regex.c b/src/regex.c
index 41c1d3f6106..1917a8480ae 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -50,6 +50,7 @@
 #include <config.h>
 
 #include <stddef.h>
+#include <stdlib.h>
 
 #ifdef emacs
 /* We need this for `regex.h', and perhaps for the Emacs include files.  */
@@ -443,25 +444,12 @@ init_syntax_once (void)
 
 #else /* not REGEX_MALLOC  */
 
-/* Emacs already defines alloca, sometimes.  */
-# ifndef alloca
-
-/* Make alloca work the best possible way.  */
-#  ifdef __GNUC__
-#   define alloca __builtin_alloca
-#  else /* not __GNUC__ */
-#   ifdef HAVE_ALLOCA_H
-#    include <alloca.h>
-#   endif /* HAVE_ALLOCA_H */
-#  endif /* not __GNUC__ */
-
-# endif /* not alloca */
-
 # ifdef emacs
 #  define REGEX_USE_SAFE_ALLOCA USE_SAFE_ALLOCA
 #  define REGEX_SAFE_FREE() SAFE_FREE ()
 #  define REGEX_ALLOCATE SAFE_ALLOCA
 # else
+#  include <alloca.h>
 #  define REGEX_ALLOCATE alloca
 # endif