decouple internal.h headers

Saves comitters' daily life by avoid #include-ing everything from
internal.h to make each file do so instead.  This would significantly
speed up incremental builds.

We take the following inclusion order in this changeset:

1.  "ruby/config.h", where _GNU_SOURCE is defined (must be the very
    first thing among everything).
2.  RUBY_EXTCONF_H if any.
3.  Standard C headers, sorted alphabetically.
4.  Other system headers, maybe guarded by #ifdef
5.  Everything else, sorted alphabetically.

Exceptions are those win32-related headers, which tend not be self-
containing (headers have inclusion order dependencies).

1 files changed, 25 insertions, 12 deletions

diff --git a/bignum.c b/bignum.c
index 3923da7d0b..8492853104 100644
--- a/bignum.c
+++ b/bignum.c
@@ -9,27 +9,40 @@
 
 **********************************************************************/
 
-#include "internal.h"
-#include "ruby/thread.h"
-#include "ruby/util.h"
-#include "id.h"
+#include "ruby/config.h"
+
+#include <ctype.h>
+#include <float.h>
+#include <math.h>
 
 #ifdef HAVE_STRINGS_H
-#include <strings.h>
+# include <strings.h>
 #endif
-#include <math.h>
-#include <float.h>
-#include <ctype.h>
+
 #ifdef HAVE_IEEEFP_H
-#include <ieeefp.h>
+# include <ieeefp.h>
 #endif
-#include "ruby_assert.h"
 
 #if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H)
-#define USE_GMP
-#include <gmp.h>
+# define USE_GMP
+# include <gmp.h>
 #endif
 
+#include "id.h"
+#include "internal.h"
+#include "internal/bignum.h"
+#include "internal/complex.h"
+#include "internal/gc.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/sanitizers.h"
+#include "internal/util.h"
+#include "internal/variable.h"
+#include "internal/warnings.h"
+#include "ruby/thread.h"
+#include "ruby/util.h"
+#include "ruby_assert.h"
+
 #define RB_BIGNUM_TYPE_P(x) RB_TYPE_P((x), T_BIGNUM)
 
 #ifndef RUBY_INTEGER_UNIFICATION