libcdecl: Use macros for packing tokens into bytes.

[cdecl99.git] / src / cdecl-internal.h

diff --git a/src/cdecl-internal.h b/src/cdecl-internal.h
index cf7fc1487469fa9881dce071111146c9f1102369..c85ca6180a781246772a8b0e0b2c45ada19991e6 100644 (file)
--- a/src/cdecl-internal.h
+++ b/src/cdecl-internal.h
@@ -24,6 +24,21 @@
 #define _(s) dgettext(PACKAGE, s)
 #define N_(s) s
 
+/*
+ * Pack a parser token into 7 bits.
+ *
+ * Bison normally numbers user-defined tokens sequentially starting from 258.
+ * If api.token,raw is used, then the numbering starts from 3.  As we have
+ * about 50 tokens, the latter case will fit in 7 bits easily; in the former
+ * case the upper bits are constant so we don't need to store them.
+ */
+#define PACK_TOKEN(x) ((x) & 0x7f)
+
+/*
+ * Expand a packed token to its original value.
+ */
+#define UNPACK_TOKEN(x) ((x) | ((T_IDENT > 256) << 8))
+
 struct cdecl_error;
 struct cdecl_declspec;