--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2008-12-25  Bruno Haible  <bruno@clisp.org>
 
+	Add support for universal builds to <stdint.h>.
+	* lib/stdint.in.h (PDFDIFF_MIN, PTRDIFF_MAX, SIZE_MAX): In Apple
+	universal builds, define directly, using _LP64.
+	* m4/stdint.m4 (gl_STDINT_TYPE_PROPERTIES): Require gl_MULTIARCH. In
+	Apple universal builds, don't test for the size and suffix of ptrdiff_t
+	and size_t.
+	* modules/stdint (Depends-on): Add multiarch.
+	(Makefile.am): Substitute APPLE_UNIVERSAL_BUILD.
+
 	New module 'multiarch'.
 	* modules/multiarch: New file.
 	* m4/multiarch.m4: New file.

--- a/lib/stdint.in.h
+++ b/lib/stdint.in.h
@@ -443,10 +443,20 @@
 /* ptrdiff_t limits */
 #undef PTRDIFF_MIN
 #undef PTRDIFF_MAX
-#define PTRDIFF_MIN  \
-   _STDINT_MIN (1, @BITSIZEOF_PTRDIFF_T@, 0@PTRDIFF_T_SUFFIX@)
-#define PTRDIFF_MAX  \
-   _STDINT_MAX (1, @BITSIZEOF_PTRDIFF_T@, 0@PTRDIFF_T_SUFFIX@)
+#if @APPLE_UNIVERSAL_BUILD@
+# if _LP64
+#  define PTRDIFF_MIN  _STDINT_MIN (1, 64, 0l)
+#  define PTRDIFF_MAX  _STDINT_MAX (1, 64, 0l)
+# else
+#  define PTRDIFF_MIN  _STDINT_MIN (1, 32, 0)
+#  define PTRDIFF_MAX  _STDINT_MAX (1, 32, 0)
+# endif
+#else
+# define PTRDIFF_MIN  \
+    _STDINT_MIN (1, @BITSIZEOF_PTRDIFF_T@, 0@PTRDIFF_T_SUFFIX@)
+# define PTRDIFF_MAX  \
+    _STDINT_MAX (1, @BITSIZEOF_PTRDIFF_T@, 0@PTRDIFF_T_SUFFIX@)
+#endif
 
 /* sig_atomic_t limits */
 #undef SIG_ATOMIC_MIN
@@ -461,7 +471,15 @@
 
 /* size_t limit */
 #undef SIZE_MAX
-#define SIZE_MAX  _STDINT_MAX (0, @BITSIZEOF_SIZE_T@, 0@SIZE_T_SUFFIX@)
+#if @APPLE_UNIVERSAL_BUILD@
+# if _LP64
+#  define SIZE_MAX  _STDINT_MAX (0, 64, 0ul)
+# else
+#  define SIZE_MAX  _STDINT_MAX (0, 32, 0ul)
+# endif
+#else
+# define SIZE_MAX  _STDINT_MAX (0, @BITSIZEOF_SIZE_T@, 0@SIZE_T_SUFFIX@)
+#endif
 
 /* wchar_t limits */
 #undef WCHAR_MIN

--- a/m4/stdint.m4
+++ b/m4/stdint.m4
@@ -1,4 +1,4 @@
-# stdint.m4 serial 31
+# stdint.m4 serial 32
 dnl Copyright (C) 2001-2008 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -373,13 +373,22 @@
 dnl of interest to stdint.in.h.
 AC_DEFUN([gl_STDINT_TYPE_PROPERTIES],
 [
-  gl_STDINT_BITSIZEOF([ptrdiff_t sig_atomic_t size_t wchar_t wint_t],
+  AC_REQUIRE([gl_MULTIARCH])
+  if test $APPLE_UNIVERSAL_BUILD = 0; then
+    gl_STDINT_BITSIZEOF([ptrdiff_t size_t],
+      [gl_STDINT_INCLUDES])
+  fi
+  gl_STDINT_BITSIZEOF([sig_atomic_t wchar_t wint_t],
     [gl_STDINT_INCLUDES])
   gl_CHECK_TYPES_SIGNED([sig_atomic_t wchar_t wint_t],
     [gl_STDINT_INCLUDES])
   gl_cv_type_ptrdiff_t_signed=yes
   gl_cv_type_size_t_signed=no
-  gl_INTEGER_TYPE_SUFFIX([ptrdiff_t sig_atomic_t size_t wchar_t wint_t],
+  if test $APPLE_UNIVERSAL_BUILD = 0; then
+    gl_INTEGER_TYPE_SUFFIX([ptrdiff_t size_t],
+      [gl_STDINT_INCLUDES])
+  fi
+  gl_INTEGER_TYPE_SUFFIX([sig_atomic_t wchar_t wint_t],
     [gl_STDINT_INCLUDES])
 ])
 

--- a/modules/stdint
+++ b/modules/stdint
@@ -13,6 +13,7 @@
 
 Depends-on:
 include_next
+multiarch
 wchar
 
 configure.ac:
@@ -36,6 +37,7 @@
 	      -e 's/@''HAVE_SYS_BITYPES_H''@/$(HAVE_SYS_BITYPES_H)/g' \
 	      -e 's/@''HAVE_LONG_LONG_INT''@/$(HAVE_LONG_LONG_INT)/g' \
 	      -e 's/@''HAVE_UNSIGNED_LONG_LONG_INT''@/$(HAVE_UNSIGNED_LONG_LONG_INT)/g' \
+	      -e 's/@''APPLE_UNIVERSAL_BUILD''@/$(APPLE_UNIVERSAL_BUILD)/g' \
 	      -e 's/@''BITSIZEOF_PTRDIFF_T''@/$(BITSIZEOF_PTRDIFF_T)/g' \
 	      -e 's/@''PTRDIFF_T_SUFFIX''@/$(PTRDIFF_T_SUFFIX)/g' \
 	      -e 's/@''BITSIZEOF_SIG_ATOMIC_T''@/$(BITSIZEOF_SIG_ATOMIC_T)/g' \