Use the IR symbol table for the IR input object

ELF linker shouldn't skip the IR object when searching the symbol table
of an archive element.  If linker doesn't know if the object file is an
IR object, it should give LTO plugin a chance to get the correct symbol
table and use the IR symbol table if the input is an IR object.

bfd/

	PR ld/18250
	PR ld/20267
	* elflink.c: Include plugin.h if BFD_SUPPORTS_PLUGINS is
	defined.
	(elf_link_is_defined_archive_symbol): Call
	bfd_link_plugin_object_p on unknown plugin object and use the
	IR symbol table if the input is an IR object.
	* plugin.c (bfd_link_plugin_object_p): New function.
	* plugin.h (bfd_link_plugin_object_p): New prototype.

ld/

	PR ld/20267
	* testsuite/ld-plugin/lto.exp (lto_link_tests): Add test for
	PR ld/20267.
	(lto_run_tests): Likewise.
	* testsuite/ld-plugin/pr20267a.c: New file.
	* testsuite/ld-plugin/pr20267b.c: Likewise.

bfd/ChangeLog

@@ -1,3 +1,15 @@
+2016-06-20  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/18250
+	PR ld/20267
+	* elflink.c: Include plugin.h if BFD_SUPPORTS_PLUGINS is
+	defined.
+	(elf_link_is_defined_archive_symbol): Call
+	bfd_link_plugin_object_p on unknown plugin object and use the
+	IR symbol table if the input is an IR object.
+	* plugin.c (bfd_link_plugin_object_p): New function.
+	* plugin.h (bfd_link_plugin_object_p): New prototype.
+
 2016-06-20  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/20276

bfd/elflink.c

@@ -28,6 +28,9 @@
 #include "safe-ctype.h"
 #include "libiberty.h"
 #include "objalloc.h"
+#ifdef BFD_SUPPORTS_PLUGINS
+#include "plugin.h"
+#endif
 
 /* This struct is used to pass information to routines called via
    elf_link_hash_traverse which must return failure.  */
@@ -3124,15 +3127,25 @@ elf_link_is_defined_archive_symbol (bfd * abfd, carsym * symdef)
   if (abfd == NULL)
     return FALSE;
 
-  /* Return FALSE if the object has been claimed by plugin.  */
-  if (abfd->plugin_format == bfd_plugin_yes)
-    return FALSE;
-
   if (! bfd_check_format (abfd, bfd_object))
     return FALSE;
 
-  /* Select the appropriate symbol table.  */
-  if ((abfd->flags & DYNAMIC) == 0 || elf_dynsymtab (abfd) == 0)
+  /* Select the appropriate symbol table.  If we don't know if the
+     object file is an IR object, give linker LTO plugin a chance to
+     get the correct symbol table.  */
+  if (abfd->plugin_format == bfd_plugin_yes
+#ifdef BFD_SUPPORTS_PLUGINS
+      || (abfd->plugin_format == bfd_plugin_unknown
+	  && bfd_link_plugin_object_p (abfd))
+#endif
+      )
+    {
+      /* Use the IR symbol table if the object has been claimed by
+	 plugin.  */
+      abfd = abfd->plugin_dummy_bfd;
+      hdr = &elf_tdata (abfd)->symtab_hdr;
+    }
+  else if ((abfd->flags & DYNAMIC) == 0 || elf_dynsymtab (abfd) == 0)
     hdr = &elf_tdata (abfd)->symtab_hdr;
   else
     hdr = &elf_tdata (abfd)->dynsymtab_hdr;

bfd/plugin.c

@@ -287,6 +287,16 @@ bfd_plugin_specified_p (void)
   return has_plugin > 0;
 }
 
+/* Return TRUE if ABFD can be claimed by linker LTO plugin.  */
+
+bfd_boolean
+bfd_link_plugin_object_p (bfd *abfd)
+{
+  if (ld_plugin_object_p)
+    return ld_plugin_object_p (abfd) != NULL;
+  return FALSE;
+}
+
 extern const bfd_target plugin_vec;
 
 /* Return TRUE if TARGET is a pointer to plugin_vec.  */

bfd/plugin.h

@@ -27,6 +27,7 @@ void bfd_plugin_set_program_name (const char *);
 void bfd_plugin_set_plugin (const char *);
 bfd_boolean bfd_plugin_target_p (const bfd_target *);
 bfd_boolean bfd_plugin_specified_p (void);
+bfd_boolean bfd_link_plugin_object_p (bfd *);
 void register_ld_plugin_object_p (const bfd_target *(*object_p) (bfd *));
 
 typedef struct plugin_data_struct

ld/ChangeLog

@@ -1,3 +1,12 @@
+2016-06-20  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/20267
+	* testsuite/ld-plugin/lto.exp (lto_link_tests): Add test for
+	PR ld/20267.
+	(lto_run_tests): Likewise.
+	* testsuite/ld-plugin/pr20267a.c: New file.
+	* testsuite/ld-plugin/pr20267b.c: Likewise.
+
 2016-06-20  H.J. Lu  <hongjiu.lu@intel.com>
 	    Alan Modra  <amodra@gmail.com>
 

ld/testsuite/ld-plugin/lto.exp

@@ -189,6 +189,15 @@ set lto_link_tests [list \
   [list "Build pr20276b.o" \
    "$plug_opt" "-flto $lto_no_fat" \
    {pr20276b.c}] \
+  [list "Build pr20267a.o" \
+   "" "" \
+   {pr20267a.c}] \
+  [list "Build libpr20267a.a" \
+   "$plug_opt" "-flto $lto_fat" \
+   {pr20267b.c} {} "libpr20267a.a"] \
+  [list "Build libpr20267b.a" \
+   "$plug_opt" "-flto $lto_no_fat" \
+   {pr20267b.c} {} "libpr20267b.a"] \
 ]
 
 if { [at_least_gcc_version 4 7] } {
@@ -341,6 +350,12 @@ set lto_run_tests [list \
   [list "Run pr20276" \
    "-O2 -flto tmpdir/pr20276a.o tmpdir/pr20276b.o" "" \
    {dummy.c} "pr20276" "pass.out" "-flto -O2" "c"] \
+  [list "Run pr20267a" \
+   "-O2 -flto tmpdir/pr20267a.o tmpdir/libpr20267a.a" "" \
+   {dummy.c} "pr20267a" "pass.out" "-flto -O2" "c"] \
+  [list "Run pr20267b" \
+   "-O2 -flto tmpdir/pr20267a.o tmpdir/libpr20267b.a" "" \
+   {dummy.c} "pr20267b" "pass.out" "-flto -O2" "c"] \
 ]
 
 if { [at_least_gcc_version 4 7] } {

ld/testsuite/ld-plugin/pr20267a.c

@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+int global_var;
+extern void abort ();
+
+int main(void)
+{
+  if (global_var != 20)
+    abort ();
+  printf ("PASS\n");
+  return 0;
+}

ld/testsuite/ld-plugin/pr20267b.c

@@ -0,0 +1 @@
+int global_var = 20;