Re: missing dependency

[Bruno Haible]

Eric Blake wrote:
> But something IS needed.  If you use gnulib-tool, but not --with-tests, then 
> nothing calls gl_FUNC_OBSTACK_PRINTF, which means that 
> HAVE_DECL_OBSTACK_PRINTF 
> is never set to 0, which causes compilation failures on non-glibc platforms 
> because obstack_printf is no longer declared in our replacement <stdio.h>.

Ah, now I see. Yes, in this case HAVE_DECL_OBSTACK_PRINTF is not set to 0, and
GNULIB_OBSTACK_PRINTF is not set to 1.

> diff --git a/m4/obstack-printf.m4 b/m4/obstack-printf.m4
> @@ -18,11 +18,6 @@ AC_DEFUN([gl_FUNC_OBSTACK_PRINTF],
>    if test $ac_cv_func_obstack_printf = no ; then
>      gl_REPLACE_OBSTACK_PRINTF
>    fi
> -
> -  AC_CHECK_DECLS_ONCE([obstack_printf])
> -  if test $ac_cv_have_decl_obstack_printf = no; then
> -    HAVE_DECL_OBSTACK_PRINTF=0
> -  fi
>  ])
> 
>  AC_DEFUN([gl_REPLACE_OBSTACK_PRINTF],
> @@ -32,4 +27,9 @@ AC_DEFUN([gl_REPLACE_OBSTACK_PRINTF],
>    if test $ac_cv_func_obstack_printf = yes; then
>      REPLACE_OBSTACK_PRINTF=1
>    fi
> +
> +  AC_CHECK_DECLS_ONCE([obstack_printf])
> +  if test $ac_cv_have_decl_obstack_printf = no; then
> +    HAVE_DECL_OBSTACK_PRINTF=0
> +  fi
>  ])

I think it's a little safer to this check also when gl_REPLACE_OBSTACK_PRINTF
is not being invoked. (Think of a platform that has obstack_printf in its
libraries but we are missing the magic that causes it to be declared in the
system's <stdio.h>.)

So the combined proposed patch would look like this:


2010-02-08  Eric Blake  <address@hidden>
            Bruno Haible  <address@hidden>

        * m4/obstack-printf.m4 (gl_DECL_OBSTACK_PRINTF): New macro, extracted
        from gl_FUNC_OBSTACK_PRINTF.
        (gl_FUNC_OBSTACK_PRINTF): Invoke it.
        * m4/obstack-printf-posix.m4 (gl_FUNC_OBSTACK_PRINTF_POSIX): Likewise.
        * lib/stdio.in.h (obstack_printf, obstack_vprintf): Declare also if
        GNULIB_OBSTACK_PRINTF_POSIX is 1 and GNULIB_OBSTACK_PRINTF is 0.

--- m4/obstack-printf.m4.orig   Tue Feb  9 00:34:39 2010
+++ m4/obstack-printf.m4        Tue Feb  9 00:33:38 2010
@@ -1,4 +1,4 @@
-# obstack-printf.m4 serial 2
+# obstack-printf.m4 serial 3
 dnl Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -19,10 +19,7 @@
     gl_REPLACE_OBSTACK_PRINTF
   fi
 
-  AC_CHECK_DECLS_ONCE([obstack_printf])
-  if test $ac_cv_have_decl_obstack_printf = no; then
-    HAVE_DECL_OBSTACK_PRINTF=0
-  fi
+  gl_DECL_OBSTACK_PRINTF
 ])
 
 AC_DEFUN([gl_REPLACE_OBSTACK_PRINTF],
@@ -33,3 +30,13 @@
     REPLACE_OBSTACK_PRINTF=1
   fi
 ])
+
+dnl Ensure obstack_printf(), obstack_vprintf() are declared (whether they are
+dnl being replaced or not).
+AC_DEFUN([gl_DECL_OBSTACK_PRINTF],
+[
+  AC_CHECK_DECLS_ONCE([obstack_printf])
+  if test $ac_cv_have_decl_obstack_printf = no; then
+    HAVE_DECL_OBSTACK_PRINTF=0
+  fi
+])
--- m4/obstack-printf-posix.m4.orig     Tue Feb  9 00:34:39 2010
+++ m4/obstack-printf-posix.m4  Tue Feb  9 00:33:46 2010
@@ -1,4 +1,4 @@
-# obstack-printf-posix.m4 serial 3
+# obstack-printf-posix.m4 serial 4
 dnl Copyright (C) 2008-2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -101,4 +101,5 @@
     gl_REPLACE_VASNPRINTF
     gl_REPLACE_OBSTACK_PRINTF
   fi
+  gl_DECL_OBSTACK_PRINTF
 ])
--- lib/stdio.in.h.orig Tue Feb  9 00:34:39 2010
+++ lib/stdio.in.h      Tue Feb  9 00:29:30 2010
@@ -386,7 +386,7 @@
 # endif
 #endif
 
-#if @GNULIB_OBSTACK_PRINTF@
+#if @GNULIB_OBSTACK_PRINTF@ || @GNULIB_OBSTACK_PRINTF_POSIX@
 # if @REPLACE_OBSTACK_PRINTF@
 #  define obstack_printf rpl_osbtack_printf
 #  define obstack_vprintf rpl_obstack_vprintf