src/types.c: Rearrange the main typeinfo table.

[adns.git] / src / internal.h

diff --git a/src/internal.h b/src/internal.h
index 58cd15d2fba69ae80e8f09bf99b71580b8cce07a..f459a24766a61c3138062f28fa04d3f5a4b7c04a 100644 (file)
--- a/src/internal.h
+++ b/src/internal.h
@@ -72,6 +72,27 @@ typedef unsigned char byte;
 
 #define MAX_POLLFDS  ADNS_POLLFDS_RECOMMENDED
 
+/* Some preprocessor hackery */
+
+#define GLUE(x, y) GLUE_(x, y)
+#define GLUE_(x, y) x##y
+
+/* C99 macro `...' must match at least one argument, so the naive definition
+ * `#define CAR(car, ...) car' won't work.  But it's easy to arrange for the
+ * tail to be nonempty if we're just going to discard it anyway. */
+#define CAR(...) CAR_(__VA_ARGS__, _)
+#define CAR_(car, ...) car
+
+/* Extracting the tail of an argument list is rather more difficult.  The
+ * following trick is based on one by Laurent Deniau to count the number of
+ * arguments to a macro, simplified in two ways: (a) it only handles up to
+ * eight arguments, and (b) it only needs to distinguish the one-argument
+ * case from many arguments. */
+#define CDR(...) CDR_(__VA_ARGS__, m, m, m, m, m, m, m, 1, _)(__VA_ARGS__)
+#define CDR_(_1, _2, _3, _4, _5, _6, _7, _8, n, ...) CDR_##n
+#define CDR_1(_)
+#define CDR_m(_, ...) __VA_ARGS__
+
 typedef enum {
   cc_user,
   cc_entex,
@@ -89,15 +110,6 @@ typedef enum {
 
 /* Shared data structures */
 
-typedef union {
-  adns_status status;
-  char *cp;
-  adns_rrtype type;
-  int i;
-  struct in_addr ia;
-  unsigned long ul;
-} rr_align;
-
 typedef struct {
   int used, avail;
   byte *buf;
@@ -190,10 +202,15 @@ union maxalign {
 typedef struct {
   void *ext;
   void (*callback)(adns_query parent, adns_query child);
+
+  union {
+    adns_rr_addr ptr_addr;
+  } tinfo; /* type-specific state for the query itself: zero-init if you
+           * don't know better. */
+
   union {
-    adns_rr_addr ptr_parent_addr;
     adns_rr_hostaddr *hostaddr;
-  } info;
+  } pinfo; /* state for use by parent's callback function */
 } qcontext;
 
 struct adns__query {