compile-file: need endian mark in .tlo files.

VM machine code is endian-specific: it consists of 32 bit
instruction words which are 32 bit in the local byte order.

Thus code assembled on a little-endian machine won't run
on a big endian-machine, or vice versa: unless we identify
the situation and byte-swap the code when we load it.

* buf.c (buf_swap32): New function.

* buf.h (buf_swap32): Declared.

* parser.c (read_file_common): Decode the third element from
the version: a Boolean indicating big endian, if true.
If the object file's endian is opposite from our endian, then
byte swap the code.

* itypes.c (itypes_init): Oops, calculation of
itypes_little_endian was broken due to classic C =/== typo.
Luckily, nothing has used this flag so far; it's been waiting
for this first use. I caught this due to testing on a PPC64
box.

* share/txr/stdlib/compiler.tl (%big-endian%, %tlo-ver%): New
variables.
(usr:compile-file): The file version comes from %tlo-ver% now,
which includes the big-endian flag.

1 files changed, 2 insertions, 0 deletions

diff --git a/buf.h b/buf.h
index 107d7608..cf394ff0 100644
--- a/buf.h
+++ b/buf.h
@@ -106,4 +106,6 @@ val buf_pprint(val buf, val stream);
 val make_buf_stream(val buf_opt);
 val get_buf_from_stream(val stream);
 
+void buf_swap32(val buf);
+
 void buf_init(void);