-# $Id: Makefile,v 1.1 2008-03-31 22:52:17 rjones Exp $
+# $Id: Makefile,v 1.2 2008-04-01 08:56:43 rjones Exp $
OCAMLFIND = ocamlfind
OCAMLMKLIB = ocamlmklib
bitmatch.cmxa: bitmatch.cmx
$(OCAMLFIND) ocamlopt -a -o $@ $^
-test:
+test: pa_bitmatch.cmo bitmatch.cma
@for f in $(TESTS); do \
echo Test: $$f; \
- $(OCAMLFIND) ocamlc -pp "camlp4o pa_bitmatch.cmo" \
+ $(OCAMLFIND) ocamlc $(OCAMLCFLAGS) -pp "camlp4o pa_bitmatch.cmo" \
-I . bitmatch.cma $$f.ml -o $$f; \
+ if [ $$? -ne 0 ]; then exit 1; fi; \
$$f; \
+ if [ $$? -ne 0 ]; then exit 1; fi; \
done
print-tests: pa_bitmatch.cmo
(* Bitmatch library.
- * $Id: bitmatch.ml,v 1.1 2008-03-31 22:52:17 rjones Exp $
+ * $Id: bitmatch.ml,v 1.2 2008-04-01 08:56:43 rjones Exp $
*)
+open Printf
+
(* A bitstring is simply the data itself (as a string), and the
* bitoffset and the bitlength within the string. Note offset/length
* are counted in bits, not bytes.
close_in chan;
bs
-(* Extraction functions (internal: called from the generated macros,
- * and the parameters should have been checked for sanity already).
+(*----------------------------------------------------------------------*)
+(* Extraction functions.
+ *
+ * NB: internal functions, called from the generated macros, and
+ * the parameters should have been checked for sanity already).
*)
+
+(* Bitstrings. *)
let extract_bitstring data off len flen =
(data, off, flen), off+flen, len-flen
let extract_remainder data off len =
(data, off, len), off+len, 0
-(* Extract and convert to numeric. *)
+(* Extract and convert to numeric. A single bit is returned as
+ * a boolean. There are no endianness or signedness considerations.
+ *)
let extract_bit data off len _ = (* final param is always 1 *)
let byteoff = off lsr 3 in
let bitmask = 1 lsl (7 - (off land 7)) in
let b = Char.code data.[byteoff] land bitmask <> 0 in
b, off+1, len-1
+
+(* Extract [2..8] bits. Because the result fits into a single
+ * byte we don't have to worry about endianness, only signedness.
+ *)
+let extract_char_unsigned data off len flen =
+ let byteoff = off lsr 3 in
+
+ (* Extract the 16 bits at byteoff and byteoff+1 (note that the
+ * second byte might not exist in the original string).
+ *)
+ let word =
+ (Char.code data.[byteoff] lsl 8) +
+ (if String.length data > byteoff+1 then Char.code data.[byteoff+1]
+ else 0) in
+
+ (* Mask off the top bits. *)
+ let bitmask = (1 lsl (16 - (off land 7))) - 1 in
+ let word = word land bitmask in
+ (* Shift right to get rid of the bottom bits. *)
+ let shift = 16 - ((off land 7) + flen) in
+ let word = word lsr shift in
+
+ word, off+flen, len-flen
(* Bitmatch library.
- * $Id: bitmatch.mli,v 1.1 2008-03-31 22:52:17 rjones Exp $
+ * $Id: bitmatch.mli,v 1.2 2008-04-01 08:56:43 rjones Exp $
*)
type bitstring = string * int * int
val extract_remainder : string -> int -> int -> bitstring * int * int
val extract_bit : string -> int -> int -> int -> bool * int * int
+
+val extract_char_unsigned : string -> int -> int -> int -> int * int * int
(* Bitmatch syntax extension.
- * $Id: pa_bitmatch.ml,v 1.1 2008-03-31 22:52:17 rjones Exp $
+ * $Id: pa_bitmatch.ml,v 1.2 2008-04-01 08:56:43 rjones Exp $
*)
open Printf
| _ -> None in
let name_of_int_extract_const = function
+ (* XXX As an enhancement we should allow a 64-bit-only
+ * mode which lets us use 'int' up to 63 bits and won't
+ * compile on 32-bit platforms.
+ *)
+ (* XXX The meaning of signed/unsigned breaks down at
+ * 31, 32, 63 and 64 bits.
+ *)
| (1, _, _) -> "extract_bit"
- | ((2|3|4|5|6|7), _, false) -> "extract_char_unsigned"
- | ((2|3|4|5|6|7), _, true) -> "extract_char_signed"
+ | ((2|3|4|5|6|7|8), _, false) -> "extract_char_unsigned"
+ | ((2|3|4|5|6|7|8), _, true) -> "extract_char_signed"
| (i, BigEndian, false) when i <= 31 -> "extract_int_be_unsigned"
| (i, BigEndian, true) when i <= 31 -> "extract_int_be_signed"
| (i, LittleEndian, false) when i <= 31 -> "extract_int_le_unsigned"
*.cmxa
01_load
05_bits
+06_ints1
+06_ints2
+06_ints3
(* Extract bits.
- * $Id: 05_bits.ml,v 1.1 2008-03-31 22:52:17 rjones Exp $
+ * $Id: 05_bits.ml,v 1.2 2008-04-01 08:56:43 rjones Exp $
*)
-open Printf
-
let bits = Bitmatch.make_bitstring 24 '\x5a' (* makes the string 0x5a5a5a *)
let () =
b8 : 1; b9 : 1; b10 : 1; b11 : 1; b12 : 1; b13 : 1; b14 : 1; b15 : 1;
b16 : 1; b17 : 1; b18 : 1; b19 : 1; b20 : 1; b21 : 1; b22 : 1; b23 : 1;
rest : -1 : bitstring ->
- assert (not b0 && b1 && not b2 && b3 && b4 && not b5 && b6 && not b7);
- assert (not b8 && b9 && not b10 && b11 && b12 && not b13 && b14 && not b15);
- assert (not b16 && b17 && not b18 && b19 && b20 && not b21 && b22 && not b23);
+ assert (not b0 && b1 && not b2 && b3 && (* 0x5 *)
+ b4 && not b5 && b6 && not b7); (* 0xA *)
+ assert (not b8 && b9 && not b10 && b11 && (* 0x5 *)
+ b12 && not b13 && b14 && not b15); (* 0xA *)
+ assert (not b16 && b17 && not b18 && b19 && (* 0x5 *)
+ b20 && not b21 && b22 && not b23); (* 0xA *)
let _, off, len = rest in
- assert (off = 24 && len = 0)
+ assert (off = 24 && len = 0) (* no further data *)
| _ ->
failwith "error: did not match\n"
--- /dev/null
+(* Extract some simple integers.
+ * $Id: 06_ints1.ml,v 1.1 2008-04-01 08:56:43 rjones Exp $
+ *)
+
+let bits = Bitmatch.make_bitstring 16 '\xcf' (* makes the string 0xcfcf *)
+
+let () =
+ bitmatch bits with
+ | n0 : 4; n1 : 4; n2 : 4; n3 : 4;
+ rest : -1 : bitstring ->
+ assert (n0 = 0xc);
+ assert (n1 = 0xf);
+ assert (n2 = 0xc);
+ assert (n3 = 0xf);
+
+ let _, off, len = rest in
+ assert (off = 16 && len = 0) (* no further data *)
+
+ | _ ->
+ failwith "error: did not match\n"
--- /dev/null
+(* Extract some simple integers.
+ * $Id: 06_ints2.ml,v 1.1 2008-04-01 08:56:43 rjones Exp $
+ *)
+
+let bits = Bitmatch.make_bitstring 16 '\xcf' (* makes the string 0xcfcf *)
+
+let () =
+ bitmatch bits with
+ | n0 : 2; n1 : 2; n2 : 2; n3 : 2; n4 : 2; n5 : 2; n6 : 2; n7 : 2;
+ rest : -1 : bitstring ->
+ assert (n0 = 0x3); (* 0xc *)
+ assert (n1 = 0x0);
+ assert (n2 = 0x3); (* 0xf *)
+ assert (n3 = 0x3);
+ assert (n4 = 0x3); (* 0xc *)
+ assert (n5 = 0x0);
+ assert (n6 = 0x3); (* 0xf *)
+ assert (n7 = 0x3);
+
+ let _, off, len = rest in
+ assert (off = 16 && len = 0) (* no further data *)
+
+ | _ ->
+ failwith "error: did not match\n"
--- /dev/null
+(* Extract some simple integers.
+ * $Id: 06_ints3.ml,v 1.1 2008-04-01 08:56:43 rjones Exp $
+ *)
+
+let bits = Bitmatch.make_bitstring 16 '\xcf' (* makes the string 0xcfcf *)
+
+let () =
+ bitmatch bits with
+ | n0 : 3; n1 : 3; n2 : 3; n3 : 3; n4 : 3; n5 : 1;
+ rest : -1 : bitstring ->
+ assert (n0 = 0b110);
+ assert (n1 = 0b011);
+ assert (n2 = 0b111);
+ assert (n3 = 0b100);
+ assert (n4 = 0b111);
+ assert (n5);
+
+ let _, off, len = rest in
+ assert (off = 16 && len = 0) (* no further data *)
+
+ | _ ->
+ failwith "error: did not match\n"
git.annexia.org / ocaml-bitstring.git / commitdiff