Re: Issuing deprecation warnings

[Daniel Kraft]

Andy Wingo wrote:
> > Thus here my question:  What's the opinion on the matter?  I'd like to
> > provide a simple patch for this issue (it is trivial, but hey :)), but
> > want to know which way to go for it.  As stated above, my feeling would
> > be to not remove the warning-issuing-methods on --disable-deprected.
>
> I agree. It is useful to have this API for extensions.

Attached is an attempt to provide a patch for this; I hope I did get 
everything right.  The default value for GUILE_WARN_DEPRECATED when 
--disable-deprecated is set is probably something to dicuss, though.

Yours,
Daniel

2008-12-28  Daniel Kraft  <address@hidden>

        * configure.in (enable_deprecated): Set SCM_WARN_DEPRECATED_DEFAULT
        even when --disable-deprecated is passed.
        * libguile/deprecation.h: Declare deprecation-issuing methods even
        if SCM_ENABLE_DEPRECATED is not set.
        * libguile/deprecation.c: Ditto.
        (scm_init_deprecation): Include full body even for unset
        SCM_ENABLE_DEPRECATED.

diff --git a/configure.in b/configure.in
index a7fd9c9..385f4d9 100644
--- a/configure.in
+++ b/configure.in
@@ -159,6 +159,7 @@ AC_ARG_ENABLE([deprecated],
 
 if test "$enable_deprecated" = no; then
   SCM_I_GSC_ENABLE_DEPRECATED=0
+  warn_default=no
 else
   if test "$enable_deprecated" = yes || test "$enable_deprecated" = ""; then
     warn_default=summary
@@ -168,9 +169,9 @@ else
     warn_default=$enable_deprecated
   fi
   SCM_I_GSC_ENABLE_DEPRECATED=1
-  AC_DEFINE_UNQUOTED(SCM_WARN_DEPRECATED_DEFAULT, "$warn_default",
-  [Define this to control the default warning level for deprecated features.])
 fi
+AC_DEFINE_UNQUOTED(SCM_WARN_DEPRECATED_DEFAULT, "$warn_default",
+[Define this to control the default warning level for deprecated features.])
 
 AC_ARG_ENABLE(elisp,
   [  --disable-elisp         omit Emacs Lisp support],,
diff --git a/libguile/deprecation.c b/libguile/deprecation.c
index 338c47c..780e246 100644
--- a/libguile/deprecation.c
+++ b/libguile/deprecation.c
@@ -41,8 +41,6 @@
 
 
 
-#if (SCM_ENABLE_DEPRECATED == 1)
-
 struct issued_warning {
   struct issued_warning *prev;
   const char *message;
@@ -138,8 +136,6 @@ print_deprecation_summary (void)
     }
 }
 
-#endif /* SCM_ENABLE_DEPRECATED == 1 */
-
 SCM_DEFINE(scm_include_deprecated_features,
           "include-deprecated-features", 0, 0, 0,
           (),
@@ -157,7 +153,6 @@ SCM_DEFINE(scm_include_deprecated_features,
 void
 scm_init_deprecation ()
 {
-#if (SCM_ENABLE_DEPRECATED == 1)
   const char *level = getenv ("GUILE_WARN_DEPRECATED");
   if (level == NULL)
     level = SCM_WARN_DEPRECATED_DEFAULT;
@@ -170,7 +165,6 @@ scm_init_deprecation ()
       SCM_WARN_DEPRECATED = 0;
       atexit (print_deprecation_summary);
     }
-#endif
 #include "libguile/deprecation.x"
 }
 
diff --git a/libguile/deprecation.h b/libguile/deprecation.h
index 7885327..05928b7 100644
--- a/libguile/deprecation.h
+++ b/libguile/deprecation.h
@@ -26,20 +26,15 @@
 
 
 
-#if (SCM_ENABLE_DEPRECATED == 1)
-
-/* These functions are _not_ deprecated, but we exclude them along
-   with the really deprecated features to be sure that no-one is
-   trying to emit deprecation warnings when libguile is supposed to be
-   clean of them.
+/* These functions are a possibly useful part of the API and not only used
+   internally, thus they are exported always, not depending on
+   SCM_ENABLE_DEPRECATED.
 */
 
 SCM_API void scm_c_issue_deprecation_warning (const char *msg);
 SCM_API void scm_c_issue_deprecation_warning_fmt (const char *msg, ...);
 SCM_API SCM scm_issue_deprecation_warning (SCM msgs);
 
-#endif
-
 SCM_API SCM scm_include_deprecated_features (void);
 SCM_INTERNAL void scm_init_deprecation (void);