Re: missing dependency

[Eric Blake]

Bruno Haible <bruno <at> clisp.org> writes:

> >     * modules/obstack-printf-posix (Depends-on): Add obstack-printf.
> 
> This is not needed. The modules 'obstack-printf-posix' and 'obstack-printf'
> are two modules that use the same source code but different .m4 macros.
> There is no need for running gl_FUNC_OBSTACK_PRINTF when we are also running
> gl_FUNC_OBSTACK_PRINTF_POSIX.

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>.

I suppose the alternative is this (untested; but I can use it instead of the 
first if it passes testing):


From: Eric Blake <address@hidden>
Date: Mon, 8 Feb 2010 15:07:14 -0700
Subject: [PATCH] obstack-printf-posix: ensure declaration

The replacement <stdio.h> was failing to declare obstack_printf
if obstack-printf-posix was used in isolation without unit tests.

* m4/obstack-printf.m4 (gl_FUNC_OBSTACK_PRINTF): Move declaration
check...
(gl_REPLACE_OBSTACK_PRINTF): ...here.
Analysis aided by Bruno Haible.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog            |    8 ++++++++
 m4/obstack-printf.m4 |   12 ++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 8c3d813..ab2834a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2010-02-08  Eric Blake  <address@hidden>
+
+       obstack-printf-posix: ensure declaration
+       * m4/obstack-printf.m4 (gl_FUNC_OBSTACK_PRINTF): Move declaration
+       check...
+       (gl_REPLACE_OBSTACK_PRINTF): ...here.
+       Analysis aided by Bruno Haible.
+
 2009-11-17  Eric Blake  <address@hidden>

        manywarnings: add more warnings
diff --git a/m4/obstack-printf.m4 b/m4/obstack-printf.m4
index ae2e5d9..5be4b42 100644
--- a/m4/obstack-printf.m4
+++ b/m4/obstack-printf.m4
@@ -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,
@@ -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
 ])
-- 
1.6.6.1