removing stdint's dependency on wchar

[Paul Eggert]

I looked into importing the md5 module into Emacs, and
found that it dragged in a whole bunch of stuff related
to wchar_t that were irrelevant to md5.  The problem is
that md5 includes stdint.h for uint32_t, and the stdint
module depends on wchar for WCHAR_MIN etc; but md5 does
not need WCHAR_MIN etc.

Here's a proposed patch to make stdint configure faster,
primarily by removing its dependency on wchar.

Independently, I'll look into removing the dependency
of md5 on stdint.

stdint: don't depend on wchar
* NEWS: Document this.
* lib/stdint.in.h: Put the wchar-related stuff inside
"#if @GNULIB_WCHAR@".
* m4/stdint.m4 (gl_STDINT_H): Require gl_STDINT_H_DEFAULTS.
Invoke gl_PREREQ_STDINT_H if building a substitute stdint.h.
(gl_PREREQ_STDINT_H): New macro.
Move gl_CHECK_NEXT_HEADERS([stdint.h]) and related code here,
from gl_STDINT_H, because it needs to be executed only if we
are building the substitute stdint.h.  Similarly for
sys/inttypes.h and other stuff needed only by the substitute.
(gl_STDINT_H_DEFAULTS): New macro, with default initializations
that should work regardless of whether the wchar module is also
used.
* m4/wchar_h.m4 (gl_WCHAR_H): Set GNULIB_WCHAR=1, as a witness,
for stdint's benefit.
* modules/stdint (Depends-on): Remove wchar.
(Makefile.in): Propagate GNULIB_WCHAR into stdint.h.
* modules/stdint-tests (Depends-on): Add wchar.
diff --git a/NEWS b/NEWS
index b203b2c..2ad3b99 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,10 @@ User visible incompatible changes

 Date        Modules         Changes

+2011-02-18  stdint          This module no longer guarantees that WCHAR_MAX,
+                            WCHAR_MIN, WINT_MAX, and WINT_MIN are #defined
+                            unless the wchar module is also used.
+
 2011-02-14  getloadavg      This module no longer #defines C_GETLOADAVG or
                             HAVE_GETLOADAVG, as the application no longer needs
                             to worry about how getloadavg is defined.  It no
diff --git a/lib/stdint.in.h b/lib/stdint.in.h
index c48be52..4c806eb 100644
--- a/lib/stdint.in.h
+++ b/lib/stdint.in.h
@@ -491,6 +491,7 @@ typedef int _verify_intmax_size[sizeof (intmax_t) == sizeof 
(uintmax_t)
 # define SIZE_MAX  _STDINT_MAX (0, @BITSIZEOF_SIZE_T@, address@hidden@)
 #endif

+#if @GNULIB_WCHAR@
 /* wchar_t limits */
 /* Get WCHAR_MIN, WCHAR_MAX.
    This include is not on the top, above, because on OSF/1 4.0 we have a
@@ -516,6 +517,7 @@ typedef int _verify_intmax_size[sizeof (intmax_t) == sizeof 
(uintmax_t)
    _STDINT_MIN (@HAVE_SIGNED_WINT_T@, @BITSIZEOF_WINT_T@, address@hidden@)
 #define WINT_MAX  \
    _STDINT_MAX (@HAVE_SIGNED_WINT_T@, @BITSIZEOF_WINT_T@, address@hidden@)
+#endif /* @GNULIB_WCHAR@ */

 #endif /* !defined __cplusplus || defined __STDC_LIMIT_MACROS */

diff --git a/m4/stdint.m4 b/m4/stdint.m4
index 26654c6..0145ceb 100644
--- a/m4/stdint.m4
+++ b/m4/stdint.m4
@@ -1,4 +1,4 @@
-# stdint.m4 serial 37
+# stdint.m4 serial 38
 dnl Copyright (C) 2001-2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -10,6 +10,7 @@ dnl Test whether <stdint.h> is supported or must be 
substituted.
 AC_DEFUN([gl_STDINT_H],
 [
   AC_PREREQ([2.59])dnl
+  AC_REQUIRE([gl_STDINT_H_DEFAULTS])

   dnl Check for long long int and unsigned long long int.
   AC_REQUIRE([AC_TYPE_LONG_LONG_INT])
@@ -45,17 +46,8 @@ AC_DEFUN([gl_STDINT_H],
   fi
   AC_SUBST([HAVE_SYS_TYPES_H])

-  gl_CHECK_NEXT_HEADERS([stdint.h])
-  if test $ac_cv_header_stdint_h = yes; then
-    HAVE_STDINT_H=1
-  else
-    HAVE_STDINT_H=0
-  fi
-  AC_SUBST([HAVE_STDINT_H])
-
   dnl Now see whether we need a substitute <stdint.h>.
-  if test $ac_cv_header_stdint_h = yes; then
-    AC_CACHE_CHECK([whether stdint.h conforms to C99],
+  AC_CACHE_CHECK([whether stdint.h conforms to C99],
       [gl_cv_header_working_stdint_h],
       [gl_cv_header_working_stdint_h=no
        AC_COMPILE_IFELSE([
@@ -272,10 +264,25 @@ static const char *macro_values[] =
               ])
          ])
       ])
-  fi
   if test "$gl_cv_header_working_stdint_h" = yes; then
     STDINT_H=
   else
+    STDINT_H=stdint.h
+    gl_PREREQ_STDINT_H
+  fi
+  AC_SUBST([STDINT_H])
+])
+
+AC_DEFUN([gl_PREREQ_STDINT_H],
+[
+    gl_CHECK_NEXT_HEADERS([stdint.h])
+    if test $ac_cv_header_stdint_h = yes; then
+      HAVE_STDINT_H=1
+    else
+      HAVE_STDINT_H=0
+    fi
+    AC_SUBST([HAVE_STDINT_H])
+
     dnl Check for <sys/inttypes.h>, and for
     dnl <sys/bitypes.h> (used in Linux libc4 >= 4.6.7 and libc5).
     AC_CHECK_HEADERS([sys/inttypes.h sys/bitypes.h])
@@ -297,9 +304,6 @@ static const char *macro_values[] =
     AC_CHECK_HEADERS_ONCE([wchar.h])

     gl_STDINT_TYPE_PROPERTIES
-    STDINT_H=stdint.h
-  fi
-  AC_SUBST([STDINT_H])
 ])

 dnl gl_STDINT_BITSIZEOF(TYPES, INCLUDES)
@@ -468,6 +472,14 @@ m4_ifdef([AC_COMPUTE_INT], [], [
   AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
 ])

+AC_DEFUN([gl_STDINT_H_DEFAULTS],
+[
+  dnl Set these to zero only if not set already, so that the default
+  dnl is OK regardless of whether the wchar module is present.
+  : ${GNULIB_WCHAR=0};    AC_SUBST([GNULIB_WCHAR])
+  : ${HAVE_WCHAR_H=0};    AC_SUBST([HAVE_WCHAR_H])
+])
+
 # Hey Emacs!
 # Local Variables:
 # indent-tabs-mode: nil
diff --git a/m4/wchar_h.m4 b/m4/wchar_h.m4
index 6255ff3..ba5ba4e 100644
--- a/m4/wchar_h.m4
+++ b/m4/wchar_h.m4
@@ -7,10 +7,11 @@ dnl with or without modifications, as long as this notice is 
preserved.

 dnl Written by Eric Blake.

-# wchar_h.m4 serial 38
+# wchar_h.m4 serial 39

 AC_DEFUN([gl_WCHAR_H],
 [
+  GNULIB_WCHAR=1
   AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
   AC_REQUIRE([gl_WCHAR_H_INLINE_OK])
   dnl Prepare for creating substitute <wchar.h>.
diff --git a/modules/stdint b/modules/stdint
index 9e5f7ad..1950397 100644
--- a/modules/stdint
+++ b/modules/stdint
@@ -14,7 +14,6 @@ m4/longlong.m4
 Depends-on:
 include_next
 multiarch
-wchar

 configure.ac:
 gl_STDINT_H
@@ -32,6 +31,7 @@ stdint.h: stdint.in.h
              -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
              -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
              -e 's|@''NEXT_STDINT_H''@|$(NEXT_STDINT_H)|g' \
+             -e 's/@''GNULIB_WCHAR''@/$(GNULIB_WCHAR)/g' \
              -e 's/@''HAVE_SYS_TYPES_H''@/$(HAVE_SYS_TYPES_H)/g' \
              -e 's/@''HAVE_INTTYPES_H''@/$(HAVE_INTTYPES_H)/g' \
              -e 's/@''HAVE_SYS_INTTYPES_H''@/$(HAVE_SYS_INTTYPES_H)/g' \
diff --git a/modules/stdint-tests b/modules/stdint-tests
index ad320b2..ed177f8 100644
--- a/modules/stdint-tests
+++ b/modules/stdint-tests
@@ -4,6 +4,7 @@ m4/wchar_t.m4
 m4/wint_t.m4

 Depends-on:
+wchar
 verify
 intprops