[PATCH] Limit BFD_SUPPORTS_PLUGINS check to plugin.h and targets.c

[Alan Modra]

On Mon, Aug 18, 2025 at 06:16:19AM -0700, H.J. Lu wrote:
> Minimize the BFD_SUPPORTS_PLUGINS check to make code more readable and
> maintainable by:
> 
> 1. Update bfd/plugin.h to define plugin functions as static inline if
> BFD_SUPPORTS_PLUGINS is 0.
> 2. Add get_plugin_target to return "plugin" if plugin is enabled.
> 3. Remove BFD_SUPPORTS_PLUGINS check from all bfd and binutils files
> except plugin.h and targets.c.
> 4. Replace the remaining BFD_SUPPORTS_PLUGINS checks with a function so
> that plugin availability is checked at run time.

You neglected to compile this on a target that disables plugins, like
i386-msdos.

OK with the following on top of your patch, and the plugin.c changelog
entry corrected.  I put back the #if BFD_SUPPORTS_PLUGINS in plugin.c
so that unused code is not compiled into libbfd with
--enable-targets=all (and so that --disable-plugins would catch errors
like the plugin_vec reference in format.c).

diff --git a/bfd/format.c b/bfd/format.c
index b2cf416e0e2..81f29c5f54f 100644
--- a/bfd/format.c
+++ b/bfd/format.c
@@ -516,18 +516,17 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
      have target_defaulted false.  Failing that, bfd_find_target will
      have chosen a default target, and target_defaulted will be true.  */
   fail_targ = NULL;
-  if (abfd->format == bfd_object
+  if (bfd_plugin_enabled ()
+      && abfd->format == bfd_object
       && abfd->target_defaulted
       && !abfd->is_linker_input
       && abfd->plugin_format != bfd_plugin_no)
     {
-      extern const bfd_target plugin_vec;
-
       if (bfd_seek (abfd, 0, SEEK_SET) != 0)
 	goto err_ret;
 
-      BFD_ASSERT (save_targ != &plugin_vec);
-      abfd->xvec = &plugin_vec;
+      BFD_ASSERT (save_targ != bfd_plugin_vec ());
+      abfd->xvec = bfd_plugin_vec ();
       bfd_set_error (bfd_error_no_error);
       cleanup = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
       if (cleanup)
diff --git a/bfd/plugin.c b/bfd/plugin.c
index 393011432a8..5e5a0b70a04 100644
--- a/bfd/plugin.c
+++ b/bfd/plugin.c
@@ -21,6 +21,8 @@
 #include "sysdep.h"
 #include "bfd.h"
 
+#if BFD_SUPPORTS_PLUGINS
+
 #include <assert.h>
 #ifdef HAVE_DLFCN_H
 #include <dlfcn.h>
@@ -656,16 +658,6 @@ bfd_link_plugin_object_p (bfd *abfd)
   return false;
 }
 
-extern const bfd_target plugin_vec;
-
-/* Return TRUE if TARGET is a pointer to plugin_vec.  */
-
-bool
-bfd_plugin_target_p (const bfd_target *target)
-{
-  return target == &plugin_vec;
-}
-
 /* Register OBJECT_P to be used by bfd_plugin_object_p.  */
 
 void
@@ -1030,3 +1022,4 @@ const bfd_target plugin_vec =
 
   NULL				/* backend_data.  */
 };
+#endif /* BFD_SUPPORTS_PLUGINS */
diff --git a/bfd/plugin.h b/bfd/plugin.h
index d78186ba7f6..f16c45c8fa0 100644
--- a/bfd/plugin.h
+++ b/bfd/plugin.h
@@ -27,10 +27,22 @@ struct ld_plugin_input_file;
 void bfd_plugin_set_program_name (const char *);
 int bfd_plugin_open_input (bfd *, struct ld_plugin_input_file *);
 void bfd_plugin_set_plugin (const char *);
-bool bfd_plugin_target_p (const bfd_target *);
 bool bfd_link_plugin_object_p (bfd *);
 void register_ld_plugin_object_p (bfd_cleanup (*object_p) (bfd *, bool));
 void bfd_plugin_close_file_descriptor (bfd *, int);
+
+static inline const bfd_target *
+bfd_plugin_vec (void)
+{
+  extern const bfd_target plugin_vec;
+  return &plugin_vec;
+}
+
+static inline bool
+bfd_plugin_target_p (const bfd_target *target)
+{
+  return target == bfd_plugin_vec ();
+}
 #else
 static inline void
 bfd_plugin_set_program_name (const char *name ATTRIBUTE_UNUSED)
@@ -49,12 +61,6 @@ bfd_plugin_set_plugin (const char *p ATTRIBUTE_UNUSED)
 {
 }
 
-static inline bool
-bfd_plugin_target_p (const bfd_target *target ATTRIBUTE_UNUSED)
-{
-  return false;
-}
-
 static inline bool
 bfd_link_plugin_object_p (bfd *abfd ATTRIBUTE_UNUSED)
 {
@@ -72,6 +78,18 @@ bfd_plugin_close_file_descriptor (bfd *abfd ATTRIBUTE_UNUSED,
 				  int fd ATTRIBUTE_UNUSED)
 {
 }
+
+static inline const bfd_target *
+bfd_plugin_vec (void)
+{
+  return NULL;
+}
+
+static inline bool
+bfd_plugin_target_p (const bfd_target *target ATTRIBUTE_UNUSED)
+{
+  return false;
+}
 #endif
 
 #endif

-- 
Alan Modra