Add symbols for global entry stubs, and report stats

[Alan Modra <amodra at gmail dot com>]

The undefined function symbols (with non-zero value) on global entry
stubs are discarded by objdump when disassembling, so give objdump
another symbol to mark the stubs.

Also fixes a couple of bugs:
- entry_section was set to .opd for ELFv2, which meant a hard error
  rather than a warning when _start wasn't defined.
- global entry stubs were not built if they were the only type of
  stub in an executable.

bfd/
	* elf64-ppc.c (ppc_stub_type): Add ppc_stub_global_entry.
	(struct ppc_link_hash_table): Increase size of stub_count array.
	(build_global_entry_stubs): Emit symbol on global entry stub.
	(ppc64_elf_build_stubs): NULL check htab->brlt.  Add global entry
	stub stats.
ld/
	* emultempl/ppc64elf.em (stub_added): Delete.
	(gld${EMULATION_NAME}_finish): Call ppc64_elf_build_stubs even when
	none of the usual stubs have been added.  Only change entry_section
	for ELFv1.

diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 3e7993e..267a925 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -3785,7 +3785,8 @@ enum ppc_stub_type {
   ppc_stub_plt_branch,
   ppc_stub_plt_branch_r2off,
   ppc_stub_plt_call,
-  ppc_stub_plt_call_r2save
+  ppc_stub_plt_call_r2save,
+  ppc_stub_global_entry
 };
 
 struct ppc_stub_hash_entry {
@@ -3959,7 +3960,7 @@ struct ppc_link_hash_table
   bfd_size_type got_reli_size;
 
   /* Statistics.  */
-  unsigned long stub_count[ppc_stub_plt_call_r2save];
+  unsigned long stub_count[ppc_stub_global_entry];
 
   /* Number of stubs against global syms.  */
   unsigned long stub_globals;
@@ -12491,6 +12492,32 @@ build_global_entry_stubs (struct elf_link_hash_entry *h, void *inf)
 	    htab->stub_error = TRUE;
 	  }
 
+	htab->stub_count[ppc_stub_global_entry - 1] += 1;
+	if (htab->params->emit_stub_syms)
+	  {
+	    size_t len = strlen (h->root.root.string);
+	    char *name = bfd_malloc (sizeof "12345678.global_entry." + len);
+
+	    if (name == NULL)
+	      return FALSE;
+
+	    sprintf (name, "%08x.global_entry.%s", s->id, h->root.root.string);
+	    h = elf_link_hash_lookup (&htab->elf, name, TRUE, FALSE, FALSE);
+	    if (h == NULL)
+	      return FALSE;
+	    if (h->root.type == bfd_link_hash_new)
+	      {
+		h->root.type = bfd_link_hash_defined;
+		h->root.u.def.section = s;
+		h->root.u.def.value = p - s->contents;
+		h->ref_regular = 1;
+		h->def_regular = 1;
+		h->ref_regular_nonweak = 1;
+		h->forced_local = 1;
+		h->non_elf = 0;
+	      }
+	  }
+
 	if (PPC_HA (off) != 0)
 	  {
 	    bfd_put_32 (s->owner, ADDIS_R12_R12 | PPC_HA (off), p);
@@ -12669,7 +12696,7 @@ ppc64_elf_build_stubs (struct bfd_link_info *info,
 	elf_link_hash_traverse (&htab->elf, build_global_entry_stubs, info);
     }
 
-  if (htab->brlt->size != 0)
+  if (htab->brlt != NULL && htab->brlt->size != 0)
     {
       htab->brlt->contents = bfd_zalloc (htab->brlt->owner,
 					 htab->brlt->size);
@@ -12843,7 +12870,8 @@ ppc64_elf_build_stubs (struct bfd_link_info *info,
 			 "  long branch  %lu\n"
 			 "  long toc adj %lu\n"
 			 "  plt call     %lu\n"
-			 "  plt call toc %lu"),
+			 "  plt call toc %lu\n"
+			 "  global entry %lu"),
 	       stub_sec_count,
 	       stub_sec_count == 1 ? "" : "s",
 	       htab->stub_count[ppc_stub_long_branch - 1],
@@ -12851,7 +12879,8 @@ ppc64_elf_build_stubs (struct bfd_link_info *info,
 	       htab->stub_count[ppc_stub_plt_branch - 1],
 	       htab->stub_count[ppc_stub_plt_branch_r2off - 1],
 	       htab->stub_count[ppc_stub_plt_call - 1],
-	       htab->stub_count[ppc_stub_plt_call_r2save - 1]);
+	       htab->stub_count[ppc_stub_plt_call_r2save - 1],
+	       htab->stub_count[ppc_stub_global_entry - 1]);
     }
   return TRUE;
 }
diff --git a/ld/emultempl/ppc64elf.em b/ld/emultempl/ppc64elf.em
index 78faf68..d45fdac 100644
--- a/ld/emultempl/ppc64elf.em
+++ b/ld/emultempl/ppc64elf.em
@@ -29,6 +29,7 @@ fragment <<EOF
 #include "elf-bfd.h"
 #include "elf64-ppc.h"
 #include "ldlex.h"
+#include "elf/ppc64.h"
 
 static asection *ppc_add_stub_section (const char *, asection *);
 static void ppc_layout_sections_again (void);
@@ -42,7 +43,6 @@ static struct ppc64_elf_params params = { NULL,
 
 /* Fake input file for stubs.  */
 static lang_input_statement_type *stub_file;
-static int stub_added = 0;
 
 /* Whether we need to call ppc_layout_sections_again.  */
 static int need_laying_out = 0;
@@ -390,7 +390,6 @@ ppc_add_stub_section (const char *stub_sec_name, asection *input_section)
   if (info.add.head == NULL)
     goto err_ret;
 
-  stub_added = 1;
   if (hook_in_stub (&info, &os->children.head))
     return stub_sec;
 
@@ -518,33 +517,33 @@ gld${EMULATION_NAME}_after_allocation (void)
 static void
 gld${EMULATION_NAME}_finish (void)
 {
+  char *msg = NULL;
+  char *line, *endline;
+
   /* e_entry on PowerPC64 points to the function descriptor for
      _start.  If _start is missing, default to the first function
      descriptor in the .opd section.  */
-  entry_section = ".opd";
-
-  if (stub_added)
+  if ((elf_elfheader (link_info.output_bfd)->e_flags & EF_PPC64_ABI) == 1)
+    entry_section = ".opd";
+
+  if (params.emit_stub_syms < 0)
+    params.emit_stub_syms = 1;
+  if (stub_file != NULL
+      && !link_info.relocatable
+      && !ppc64_elf_build_stubs (&link_info, config.stats ? &msg : NULL))
+    einfo ("%X%P: can not build stubs: %E\n");
+
+  fflush (stdout);
+  for (line = msg; line != NULL; line = endline)
     {
-      char *msg = NULL;
-      char *line, *endline;
-
-      if (params.emit_stub_syms < 0)
-	params.emit_stub_syms = 1;
-      if (!ppc64_elf_build_stubs (&link_info, config.stats ? &msg : NULL))
-	einfo ("%X%P: can not build stubs: %E\n");
-
-      fflush (stdout);
-      for (line = msg; line != NULL; line = endline)
-	{
-	  endline = strchr (line, '\n');
-	  if (endline != NULL)
-	    *endline++ = '\0';
-	  fprintf (stderr, "%s: %s\n", program_name, line);
-	}
-      fflush (stderr);
-      if (msg != NULL)
-	free (msg);
+      endline = strchr (line, '\n');
+      if (endline != NULL)
+	*endline++ = '\0';
+      fprintf (stderr, "%s: %s\n", program_name, line);
     }
+  fflush (stderr);
+  if (msg != NULL)
+    free (msg);
 
   ppc64_elf_restore_symbols (&link_info);
   finish_default ();

-- 
Alan Modra
Australia Development Lab, IBM