Uncomment run-time objcode alignment check.

This should now work thanks to the changes in
28b119ee3da0f4b14cb87e638794d22843778cda ("make sure all programs are
8-byte aligned").  This commit is a follow-up to
ec99fe8ecb412e49e8e981246eb62ca46b32754b ("Add FIXMEs about misaligned
objcode-metas.").

* libguile/objcodes.c (scm_c_make_objcode_slice): Uncomment assertion
  that checks for proper alignment of PTR.

* module/language/assembly/compile-bytecode.scm (write-bytecode): Update
  comment about META's alignment.

diff --git a/libguile/objcodes.c b/libguile/objcodes.c
index 19c2406..5466ecc 100644 (file)
--- a/libguile/objcodes.c
+++ b/libguile/objcodes.c
@@ -119,10 +119,10 @@ scm_c_make_objcode_slice (SCM parent, const scm_t_uint8 *ptr)
                                scm_from_uint32 (parent_data->len),
                                scm_from_uint32 (parent_data->metalen)));
 
-#if 0
-  /* FIXME: We currently generate bytecode where the objcode-meta isn't
-     suitable aligned, which is an issue on some arches (e.g., SPARC).  */
-  assert ((((uintptr_t) ptr) & (__alignof__ (struct scm_objcode) - 1UL)) == 0);
+#ifdef __GNUC__ /* we need `__alignof__' */
+  /* Make sure bytecode for the objcode-meta is suitable aligned.  Failing to
+     do so leads to SIGBUS/SIGSEGV on some arches (e.g., SPARC).  */
+  assert ((((scm_t_bits) ptr) & (__alignof__ (struct scm_objcode) - 1UL)) == 0);
 #endif
 
   data = (struct scm_objcode*)ptr;

diff --git a/module/language/assembly/compile-bytecode.scm b/module/language/assembly/compile-bytecode.scm
index c49c200..4706cce 100644 (file)
--- a/module/language/assembly/compile-bytecode.scm
+++ b/module/language/assembly/compile-bytecode.scm
@@ -130,9 +130,9 @@
                                (set! i (1+ i))
                                (if (> i 0) (write-byte x))))
                       (get-addr (lambda () i)))
-               ;; FIXME: We should add padding here so that META's bytecode
-               ;; meets the alignment requirements of `scm_objcode'.  See
-               ;; `scm_c_make_objcode_slice ()'.
+               ;; META's bytecode meets the alignment requirements of
+               ;; `scm_objcode', thanks to the alignment computed in
+               ;; `(language assembly)'.
                (write-bytecode meta write get-addr '()))))
         ((make-char32 ,x) (write-uint32-be x))
         ((load-number ,str) (write-loader str))