plugin: Use LDPT_ADD_SYMBOLS_V2 to get symbol type

Since LTO plugin may generate more than one ltrans.o file from one input
IR object as LTO wrapper ignores -flto-partition=none:

lto-wrapper.c:608:

   604          /* Drop arguments that we want to take from the link line.  */
   605          case OPT_flto_:
   606          case OPT_flto:
   607          case OPT_flto_partition_:
   608            continue;

the LTO wrapper approach is not only slow but also unreliable.  Since
the LTO plugin API has been extended to add LDPT_ADD_SYMBOLS_V2 with
symbol type and section kind, we can use LDPT_ADD_SYMBOLS_V2 to get
symbol type, instead of invoking the LTO wrapper.

	PR binutils/25640
	* plugin.c (plugin_list_entry): Add has_symbol_type.
	(add_symbols_v2): New function.
	(bfd_plugin_open_input): Don't invoke LTO wrapper if LTO plugin
	provides symbol type.
	(try_load_plugin): Add LDPT_ADD_SYMBOLS_V2.
	(bfd_plugin_canonicalize_symtab): Use LTO plugin symbol type if
	available.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index e04f008779319e3fde07e6ab25488c20f76e8825..47ae881c2536ed1df8d56fe390c46d75afaa64da 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,14 @@
+2020-03-19  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR binutils/25640
+       * plugin.c (plugin_list_entry): Add has_symbol_type.
+       (add_symbols_v2): New function.
+       (bfd_plugin_open_input): Don't invoke LTO wrapper if LTO plugin
+       provides symbol type.
+       (try_load_plugin): Add LDPT_ADD_SYMBOLS_V2.
+       (bfd_plugin_canonicalize_symtab): Use LTO plugin symbol type if
+       available.
+
 2020-03-20  Alan Modra  <amodra@gmail.com>
 
        * coff-rs6000.c (_bfd_xcoff_slurp_armap): Ensure size is large

diff --git a/bfd/plugin.c b/bfd/plugin.c
index a0f172d363793753601db6afa892c97f79da0aab..13549d24e7ef15ee295b80aa8742c7f02deb524d 100644 (file)
--- a/bfd/plugin.c
+++ b/bfd/plugin.c
@@ -136,6 +136,7 @@ struct plugin_list_entry
   asymbol **real_syms;
   int lto_nsyms;
   const struct ld_plugin_symbol *lto_syms;
+  bfd_boolean has_symbol_type;
 
   struct plugin_list_entry *next;
 
@@ -503,6 +504,14 @@ add_symbols (void * handle,
   return LDPS_OK;
 }
 
+static enum ld_plugin_status
+add_symbols_v2 (void *handle, int nsyms,
+               const struct ld_plugin_symbol *syms)
+{
+  current_plugin->has_symbol_type = TRUE;
+  return add_symbols (handle, nsyms, syms);
+}
+
 int
 bfd_plugin_open_input (bfd *ibfd, struct ld_plugin_input_file *file)
 {
@@ -560,7 +569,8 @@ try_claim (bfd *abfd)
       current_plugin->claim_file (&file, &claimed);
       if (claimed)
        {
-         if (current_plugin->all_symbols_read)
+         if (current_plugin->all_symbols_read
+             && !current_plugin->has_symbol_type)
            {
              struct plugin_data_struct *plugin_data
                = abfd->tdata.plugin_data;
@@ -602,7 +612,7 @@ try_load_plugin (const char *pname,
                 bfd *abfd, bfd_boolean build_list_p)
 {
   void *plugin_handle;
-  struct ld_plugin_tv tv[12];
+  struct ld_plugin_tv tv[13];
   int i;
   ld_plugin_onload onload;
   enum ld_plugin_status status;
@@ -665,6 +675,10 @@ try_load_plugin (const char *pname,
   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
   tv[i].tv_u.tv_add_symbols = add_symbols;
 
+  ++i;
+  tv[i].tv_tag = LDPT_ADD_SYMBOLS_V2;
+  tv[i].tv_u.tv_add_symbols = add_symbols_v2;
+
   if (get_lto_wrapper (plugin_list_iter))
     {
       ++i;
@@ -977,9 +991,15 @@ bfd_plugin_canonicalize_symtab (bfd *abfd,
   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
   long nsyms = plugin_data->nsyms;
   const struct ld_plugin_symbol *syms = plugin_data->syms;
-  static asection fake_section
-    = BFD_FAKE_SECTION (fake_section, NULL, "plug", 0,
+  static asection fake_text_section
+    = BFD_FAKE_SECTION (fake_text_section, NULL, "plug", 0,
                        SEC_ALLOC | SEC_LOAD | SEC_CODE | SEC_HAS_CONTENTS);
+  static asection fake_data_section
+    = BFD_FAKE_SECTION (fake_data_section, NULL, "plug", 0,
+                       SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS);
+  static asection fake_bss_section
+    = BFD_FAKE_SECTION (fake_bss_section, NULL, "plug", 0,
+                       SEC_ALLOC);
   static asection fake_common_section
     = BFD_FAKE_SECTION (fake_common_section, NULL, "plug", 0, SEC_IS_COMMON);
   int i, j;
@@ -1014,16 +1034,34 @@ bfd_plugin_canonicalize_symtab (bfd *abfd,
          break;
        case LDPK_DEF:
        case LDPK_WEAKDEF:
-         s->section = &fake_section;
-         if (real_nsyms)
-           /* Use real LTO symbols if possible.  */
-           for (j = 0; j < real_nsyms; j++)
-             if (real_syms[j]->name
-                 && strcmp (syms[i].name, real_syms[j]->name) == 0)
-               {
-                 s->section = real_syms[j]->section;
-                 break;
-               }
+         if (current_plugin->has_symbol_type)
+           switch (syms[i].symbol_type)
+             {
+             case LDST_UNKNOWN:
+               /* What is the best fake section for LDST_UNKNOWN?  */
+             case LDST_FUNCTION:
+               s->section = &fake_text_section;
+               break;
+             case LDST_VARIABLE:
+               if (syms[i].section_kind == LDSSK_BSS)
+                 s->section = &fake_bss_section;
+               else
+                 s->section = &fake_data_section;
+               break;
+             }
+         else
+           {
+             s->section = &fake_text_section;
+             if (real_nsyms)
+               /* Use real LTO symbols if possible.  */
+               for (j = 0; j < real_nsyms; j++)
+                 if (real_syms[j]->name
+                     && strcmp (syms[i].name, real_syms[j]->name) == 0)
+                   {
+                     s->section = real_syms[j]->section;
+                     break;
+                   }
+           }
          break;
        default:
          BFD_ASSERT (0);