Use Gnulib's `alignof' module.

* m4/gnulib-cache.m4: Use `alignof'.

* libguile/objcodes.c (scm_c_make_objcode_slice): Use `alignof_type'.

lib/Makefile.am

@@ -9,7 +9,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl --libtool --macro-prefix=gl --no-vc-files alloca-opt autobuild byteswap canonicalize-lgpl environ extensions flock fpieee full-read full-write havelib iconv_open-utf inet_ntop inet_pton lib-symbol-versions lib-symbol-visibility libunistring putenv stdlib strcase strftime striconveh string verify vsnprintf
+# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl --libtool --macro-prefix=gl --no-vc-files alignof alloca-opt autobuild byteswap canonicalize-lgpl environ extensions flock fpieee full-read full-write havelib iconv_open-utf inet_ntop inet_pton lib-symbol-versions lib-symbol-visibility libunistring putenv stdlib strcase strftime striconveh string verify vsnprintf
 
 AUTOMAKE_OPTIONS = 1.5 gnits subdir-objects
 

libguile/objcodes.c

@@ -27,6 +27,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <assert.h>
+#include <alignof.h>
 
 #include "_scm.h"
 #include "vm-bootstrap.h"
@@ -119,11 +120,10 @@ scm_c_make_objcode_slice (SCM parent, const scm_t_uint8 *ptr)
 				scm_from_uint32 (parent_data->len),
 				scm_from_uint32 (parent_data->metalen)));
 
-#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);
+  assert ((((scm_t_bits) ptr) &
-#endif
+	   (alignof_type (struct scm_objcode) - 1UL)) == 0);
 
   data = (struct scm_objcode*)ptr;
   if (data->base + data->len + data->metalen > parent_data->base + parent_data->len + parent_data->metalen)

m4/gnulib-cache.m4

@@ -15,11 +15,12 @@
 
 
 # Specification in the form of a command-line invocation:
-#   gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl --libtool --macro-prefix=gl --no-vc-files alloca-opt autobuild byteswap canonicalize-lgpl environ extensions flock fpieee full-read full-write havelib iconv_open-utf inet_ntop inet_pton lib-symbol-versions lib-symbol-visibility libunistring putenv stdlib strcase strftime striconveh string verify vsnprintf
+#   gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl --libtool --macro-prefix=gl --no-vc-files alignof alloca-opt autobuild byteswap canonicalize-lgpl environ extensions flock fpieee full-read full-write havelib iconv_open-utf inet_ntop inet_pton lib-symbol-versions lib-symbol-visibility libunistring putenv stdlib strcase strftime striconveh string verify vsnprintf
 
 # Specification in the form of a few gnulib-tool.m4 macro invocations:
 gl_LOCAL_DIR([])
 gl_MODULES([
+  alignof
   alloca-opt
   autobuild
   byteswap