#
# * the object-like macro LOPT_PACK_BITS expands to an integer constant
# expression, suitable for use in #if directives, that specifies the
-# minimum number of bits required by the encoding.
+# minimum number of bits required by the encoding. LOPT_PACK_BITS2
+# is the same, but rounded up to the next power of two greater than
+# or equal to 8.
#
# * the object-like macro LOPTS_PACKED_INITIALIZER expands to a
# comma-separated sequence of integer constant expressions, suitable
# Currently, this only works if none of the options use action specifications
# (as these would require encoding user-specified pointer expressions and
# arbitrary int values).
-function output_packed_macros(i, tmp, accum, max)
+function output_packed_macros(i, tmp, accum, max, totalbits)
{
- print "\n#define LOPT_PACK_BITS (LOPT_SC_BITS + LOPT_HA_BITS + LOPT_LS_BITS)";
+ print "";
# determine number of bits to encode offsets in SOPT_STRING
max = length(sopt_string);
- accum = 0;
+ totalbits = accum = 0;
for (i = 1; i <= max; i *= 2) {
accum++;
}
print "#define LOPT_SC_BITS " accum;
+ totalbits += accum;
# determine number of bits to encode has_arg values
max = 0;
if (tmp > max)
max = tmp;
}
- print "#define LOPT_HA_BITS " (max > 1 ? 2 : max > 0 ? 1 : 0);
+ accum = (max > 1 ? 2 : max > 0 ? 1 : 0);
+ print "#define LOPT_HA_BITS " accum;
+ totalbits += accum;
# determine number of bits to encode offsets in lopt_strings
max = 0;
accum++;
}
print "#define LOPT_LS_BITS " accum;
+ totalbits += accum;
+
+ print "#define LOPT_PACK_BITS " totalbits;
+ for (i = 8; i < totalbits; i *= 2)
+ ;
+ print "#define LOPT_PACK_BITS2 " i;
# Now emit the packed initializer macro
print "\n#define LOPTS_PACKED_INITIALIZER \\";
--- /dev/null
+/*
+ * Copyright © 2023 Nick Bowler
+ *
+ * License WTFPL2: Do What The Fuck You Want To Public License, version 2.
+ * This is free software: you are free to do what the fuck you want to.
+ * There is NO WARRANTY, to the extent permitted by law.
+ */
+
+#ifndef DX_XTRA_H_
+#define DX_XTRA_H_
+
+#define XTRA_PASTE(a, b) a ## b
+#define XTRA_PASTE2(a, b) XTRA_PASTE(a, b)
+
+#define XTRA_ARRAYSIZE(a) (sizeof (a) / sizeof (a)[0])
+
+/*
+ * This macro may be used to simplify construction of a 'struct option'
+ * array from the packed format produced by gen-options.awk.
+ *
+ * Expanding this in a function will
+ *
+ * (1) declare a constant array with static storage duration that
+ * contains the packed representation, and
+ * (2) declare an array of struct option of suitable length, with
+ * the given name, and
+ * (3) emit code to fill the struct option array from the packed
+ * representation.
+ *
+ * The uint_leastXX_t typedefs must be in scope in order to use this macro.
+ */
+#define XTRA_PACKED_LOPTS(name) \
+ static const XTRA_PASTE2(uint_least, XTRA_PASTE2(LOPT_PACK_BITS2, _t)) \
+ name##_packed[] = { LOPTS_PACKED_INITIALIZER }; \
+ struct option name[XTRA_ARRAYSIZE(name##_packed) + 1] = {0}; \
+ do { \
+ unsigned i; \
+ for (i = 0; i < XTRA_ARRAYSIZE(name##_packed); i++) \
+ LOPT_UNPACK(name[i], name##_packed[i]); \
+ } while (0)
+
+#endif