strip: Don't treat fat IR objects as plugin object

Fat IR objects contains both regular sections and IR sections.  After

commit 717a38e9a02109fcbcb18bb2ec3aa251e2ad0a0d
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Sun May 4 05:12:46 2025 +0800

    strip: Add GCC LTO IR support

"strip --strip-debug" no longer strips debug sections in fat IR objects
since fat IR objects are recognized as plugin object and copied as unknown
objects.  Add a is_strip_input field to bfd to indicate called from strip.
Update bfd_check_format_matches not to treat archive member nor standalone
fat IR object as IR object so that strip can remove debug and IR sections
in fat IR object.  For archive member, it is copied as an unknown object
if the plugin target is in use or it is a slim IR object.  For standalone
fat IR object, it is copied as non-IR object.

bfd/

	PR binutils/33246
	* archive.c: Include "plugin-api.h" and "plugin.h" if plugin is
	enabled.
	(_bfd_compute_and_write_armap): Don't complain plugin is needed
	when the plugin target is in use.
	* bfd-in2.h: Regenerated.
	* bfd.c (bfd): Add is_strip_input.
	* format.c (bfd_set_lto_type): If there is .llvm.lto section,
	set LTO type to lto_fat_ir_object.
	(bfd_check_format_matches): Don't set LTO type when setting
	format.  When called from strip, don't treat archive member nor
	standalone fat IR object as an IR object.
	* plugin.c (bfd_plugin_get_symbols_in_object_only): Copy LTO
	type derived from input sections.

nm/

	PR binutils/33246
	* nm.c (filter_symbols): Don't complain plugin is needed when
	the plugin target is in use.
	(display_rel_file): Likewise.
	* objcopy.c (copy_archive): Set the BFD is_strip_input field of
	archive member to 1 to indicate called from strip.  Also copy
	slim IR archive member as unknown object.
	(copy_file): Set the BFD is_strip_input field of input bfd to
	1 to indicate called from strip.
	(strip_main): Keep .gnu.debuglto_* sections unless all GCC LTO
	sections will be removed.

ld/

	PR binutils/33246
	* testsuite/ld-plugin/lto-binutils.exp (run_pr33246_test): New.
	Run binutils/33246 tests with GCC and Clang.
	* testsuite/ld-plugin/pr33246.c: New file.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>

5 files changed, 39 insertions, 5 deletions

diff --git a/bfd/archive.c b/bfd/archive.c
index c61d4b1..697b2ed 100644
--- a/bfd/archive.c
+++ b/bfd/archive.c
@@ -141,6 +141,10 @@ SUBSECTION
 #include "hashtab.h"
 #include "filenames.h"
 #include "bfdlink.h"
+#if BFD_SUPPORTS_PLUGINS
+#include "plugin-api.h"
+#include "plugin.h"
+#endif
 
 #ifndef errno
 extern int errno;
@@ -2343,6 +2347,9 @@ _bfd_compute_and_write_armap (bfd *arch, unsigned int elength)
 	  long src_count;
 
 	  if (bfd_get_lto_type (current) == lto_slim_ir_object
+#if BFD_SUPPORTS_PLUGINS
+	      && !bfd_plugin_target_p (current->xvec)
+#endif
 	      && report_plugin_err)
 	    {
 	      report_plugin_err = false;
@@ -2400,6 +2407,9 @@ _bfd_compute_and_write_armap (bfd *arch, unsigned int elength)
 
 		      if (bfd_lto_slim_symbol_p (current,
 						 syms[src_count]->name)
+#if BFD_SUPPORTS_PLUGINS
+			  && !bfd_plugin_target_p (current->xvec)
+#endif
 			  && report_plugin_err)
 			{
 			  report_plugin_err = false;
diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index b013ef9..12512a3 100644
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@@ -2131,6 +2131,9 @@ struct bfd
   /* Set if this is the linker input BFD.  */
   unsigned int is_linker_input : 1;
 
+  /* Set if this is the strip input BFD.  */
+  unsigned int is_strip_input : 1;
+
   /* If this is an input for a compiler plug-in library.  */
   ENUM_BITFIELD (bfd_plugin_format) plugin_format : 2;
 
diff --git a/bfd/bfd.c b/bfd/bfd.c
index 858ab5c..4aded68 100644
--- a/bfd/bfd.c
+++ b/bfd/bfd.c
@@ -296,6 +296,9 @@ CODE_FRAGMENT
 .  {* Set if this is the linker input BFD.  *}
 .  unsigned int is_linker_input : 1;
 .
+.  {* Set if this is the strip input BFD.  *}
+.  unsigned int is_strip_input : 1;
+.
 .  {* If this is an input for a compiler plug-in library.  *}
 .  ENUM_BITFIELD (bfd_plugin_format) plugin_format : 2;
 .
diff --git a/bfd/format.c b/bfd/format.c
index d2bc318..bd9fa8d 100644
--- a/bfd/format.c
+++ b/bfd/format.c
@@ -389,6 +389,11 @@ bfd_set_lto_type (bfd *abfd ATTRIBUTE_UNUSED)
 	    abfd->object_only_section = sec;
 	    break;
 	  }
+	else if (strcmp (sec->name, ".llvm.lto") == 0)
+	  {
+	    type = lto_fat_ir_object;
+	    break;
+	  }
 	else if (lsection.major_version == 0
 		 && startswith (sec->name, ".gnu.lto_.lto.")
 		 && bfd_get_section_contents (abfd, sec, &lsection, 0,
@@ -453,10 +458,7 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
     }
 
   if (abfd->format != bfd_unknown)
-    {
-      bfd_set_lto_type (abfd);
-      return abfd->format == format;
-    }
+    return abfd->format == format;
 
   if (matching != NULL || *bfd_associated_vector != NULL)
     {
@@ -510,7 +512,20 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
 
       cleanup = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
 
-      if (cleanup)
+      /* When called from strip, don't treat archive member nor
+	 standalone fat IR object as an IR object.  For archive
+	 member, it will be copied as an unknown object if the
+	 plugin target is in use or it is a slim IR object.  For
+	 standalone fat IR object, it will be copied as non-IR
+	 object.  */
+      if (cleanup
+#if BFD_SUPPORTS_PLUGINS
+	  && (!abfd->is_strip_input
+	      || !bfd_plugin_target_p (abfd->xvec)
+	      || (abfd->lto_type != lto_fat_ir_object
+		  && abfd->my_archive == NULL))
+#endif
+	  )
 	goto ok_ret;
 
       /* For a long time the code has dropped through to check all
diff --git a/bfd/plugin.c b/bfd/plugin.c
index ebdf250..43ca444 100644
--- a/bfd/plugin.c
+++ b/bfd/plugin.c
@@ -206,6 +206,9 @@ bfd_plugin_get_symbols_in_object_only (bfd *abfd)
 	  bfd_close (nbfd);
 	  return;
 	}
+
+      /* Copy LTO type derived from input sections.  */
+      abfd->lto_type = nbfd->lto_type;
     }
   else
     {