gazagnaire.org
Mach-O (macOS / iOS) binary reader in pure OCaml
mach-o: restore hexadecimal magic in rejection messages
The optint migration switched the not-a-Mach-O and bad-magic messages to Optint.pp, which prints decimal; a magic is only recognisable in hex, and the README's documented output says so. Print the unsigned value with 0x%08x as before, and compare magics with Optint.equal rather than the polymorphic operators.
author
Thomas Gazagnaire
date
(Jul 16, 2026, 7:57 PM UTC)
commit
710fb47f
710fb47f1110c59cb77420f2ffe6fc347493c044
parent
df822df3
df822df3fce1e77cf777ff487bcb6a0360f67612
+5
-4
+5
-4
lib/mach_o.ml
+5
-4
lib/mach_o.ml
···
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in
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let* () =
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guard
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-
(u32_le data off <> mh_magic_64)
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+
(not (Optint.equal (u32_le data off) mh_magic_64))
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"fat slice is not a 64-bit Mach-O"
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in
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Ok off
···
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slice for a fat binary. *)
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let thin_base data ~len =
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let magic = u32_le data 0 in
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if magic = mh_magic_64 then Ok 0
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+
if Optint.equal magic mh_magic_64 then Ok 0
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else
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let fat = u32_be_word data 0 in
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if Optint.equal fat fat_magic then pick_fat data ~len ~is64:false
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else if Optint.equal fat fat_magic_64 then pick_fat data ~len ~is64:true
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else err "not a 64-bit Mach-O (magic %a)" Optint.pp magic
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else err "not a 64-bit Mach-O (magic 0x%08x)" (Optint.to_unsigned_int magic)
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(* Read the defined symbols, after bounds-checking the table extents. *)
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let read_symtab data ~len = function
···
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let* () =
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Fmt.kstr
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(guard (not (Optint.equal hdr.magic mh_magic_64)))
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"bad Mach magic %a" Optint.pp hdr.magic
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+
"bad Mach magic 0x%08x"
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+
(Optint.to_unsigned_int hdr.magic)
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in
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let lc_off = base + header_size in
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let end_lc = lc_off + hdr.sizeofcmds in