op_reg_common.h: Continue refactoring

The new op_reg_common.h did not have in it all the things that made
sense for it to have, including some comment changes that I should have
made when I created it.

I also realized the the new mechanism of using shifts allowed
RXf_PMf_STD_PMMOD_SHIFT to actually control things, rather than be a
 #define that one had to remember to change if those things changed
independently.

Finally, I created a check so that adding bits without adding them to
RXf_PMf_COMPILETIME will force a compilation error.  (This came from the
school of hard knocks)

1 files changed, 34 insertions, 8 deletions

diff --git a/op_reg_common.h b/op_reg_common.h
index b6a4f75f5f..d4e39873e1 100644
--- a/op_reg_common.h
+++ b/op_reg_common.h
@@ -10,18 +10,33 @@
  */
 
 /* These defines are used in both op.h and regexp.h  The definitions use the
- * shift form so that ext/B/defsubs_h.PL will pick them up */
-#define RXf_PMf_MULTILINE	(1 << 0)	/* /m */
-#define RXf_PMf_SINGLELINE	(1 << 1)	/* /s */
-#define RXf_PMf_FOLD	        (1 << 2)	/* /i */
-#define RXf_PMf_EXTENDED	(1 << 3)	/* /x */
-#define RXf_PMf_KEEPCOPY	(1 << 4)	/* /p */
-#define RXf_PMf_LOCALE		(1 << 5)
+ * shift form so that ext/B/defsubs_h.PL will pick them up.
+ *
+ * Data structures used in the two headers have common fields, and in fact one
+ * is copied onto the other.  This makes it easy to keep them in sync */
+
+/* This tells where the first of these bits is.  Setting it to 0 saved cycles
+ * and memory.  I (khw) think the code will work if changed back, but haven't
+ * tested it */
+#define RXf_PMf_STD_PMMOD_SHIFT 0
+
+/* The bits need to be ordered so that the msix are contiguous starting at bit
+ * RXf_PMf_STD_PMMOD_SHIFT, followed by the p.  See STD_PAT_MODS and
+ * INT_PAT_MODS in regexp.h for the reason contiguity is needed */
+#define RXf_PMf_MULTILINE      (1 << (RXf_PMf_STD_PMMOD_SHIFT+0))    /* /m */
+#define RXf_PMf_SINGLELINE     (1 << (RXf_PMf_STD_PMMOD_SHIFT+1))    /* /s */
+#define RXf_PMf_FOLD           (1 << (RXf_PMf_STD_PMMOD_SHIFT+2))    /* /i */
+#define RXf_PMf_EXTENDED       (1 << (RXf_PMf_STD_PMMOD_SHIFT+3))    /* /x */
+#define RXf_PMf_KEEPCOPY       (1 << (RXf_PMf_STD_PMMOD_SHIFT+4))    /* /p */
+#define RXf_PMf_LOCALE         (1 << (RXf_PMf_STD_PMMOD_SHIFT+5))
 
 /* Next available bit after the above.  Name begins with '_' so won't be
  * exported by B */
-#define _RXf_PMf_SHIFT_NEXT 6
+#define _RXf_PMf_SHIFT_NEXT (RXf_PMf_STD_PMMOD_SHIFT+6)
 
+/* Mask of the above bits.  These need to be transferred from op_pmflags to
+ * re->extflags during compilation */
+#define RXf_PMf_COMPILETIME    (RXf_PMf_MULTILINE|RXf_PMf_SINGLELINE|RXf_PMf_LOCALE|RXf_PMf_FOLD|RXf_PMf_EXTENDED|RXf_PMf_KEEPCOPY)
 
 /* These copies need to be numerical or defsubs_h.PL won't know about them. */
 #define PMf_MULTILINE    1<<0
@@ -34,3 +49,14 @@
 #if PMf_MULTILINE != RXf_PMf_MULTILINE || PMf_SINGLELINE != RXf_PMf_SINGLELINE || PMf_FOLD != RXf_PMf_FOLD || PMf_EXTENDED != RXf_PMf_EXTENDED || PMf_KEEPCOPY != RXf_PMf_KEEPCOPY || PMf_LOCALE != RXf_PMf_LOCALE
 #   error RXf_PMf defines are wrong
 #endif
+
+#define PMf_COMPILETIME RXf_PMf_COMPILETIME
+
+/*  Error check that haven't left something out of this.  This isn't done
+ *  directly in the #define because doing so confuses regcomp.pl.
+ *  (2**n - 1) is n 1 bits, so the below gets the contiguous bits between the
+ *  beginning and ending shifts */
+#if RXf_PMf_COMPILETIME != (((1 << (_RXf_PMf_SHIFT_NEXT))-1) \
+                            & (~((1 << RXf_PMf_STD_PMMOD_SHIFT)-1)))
+#   error RXf_PMf_COMPILETIME is invalid
+#endif