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, 5 insertions, 1 deletions

diff --git a/share/txr/stdlib/compiler.tl b/share/txr/stdlib/compiler.tl
index 6a8bc59c..a10f4f14 100644
--- a/share/txr/stdlib/compiler.tl
+++ b/share/txr/stdlib/compiler.tl
@@ -1313,6 +1313,10 @@
 
 (defvar *eval*)
 
+(defvarl %big-endian% (equal (ffi-put 1 (ffi uint32)) #b'00000001'))
+
+(defvarl %tlo-ver% ^(0 0 ,%big-endian%))
+
 (defun open-compile-streams (in-path out-path)
   (let* ((rsuff (r$ %file-suff-rx% in-path))
          (suff (if rsuff [in-path rsuff]))
@@ -1386,7 +1390,7 @@
                                 (sys:vm-execute-toplevel vm-desc))
                               (when *emit*
                                 out.(add flat-vd)))))))))
-          (prinl '(0 0) out-stream)
+          (prinl %tlo-ver% out-stream)
           (unwind-protect
             (whilet ((obj (read in-stream *stderr* err-ret))
                      ((neq obj err-ret)))