re PR lto/47247 (Linker plugin specification makes it difficult to handle COMDATs)

	PR lto/47247
	* lto-plugin.c (get_symbols_v2): New variable.
	(write_resolution): Use V2 API when available.
	(onload): Handle LDPT_GET_SYMBOLS_V2.

	* lto-symtab.c (lto_symtab_resolve_symbols): Do not resolve
	when resolution is already availbale from plugin.
	(lto_symtab_merge_decls_1): Handle LDPR_PREVAILING_DEF_IRONLY_EXP.
	* cgraph.c (ld_plugin_symbol_resolution): Add prevailing_def_ironly_exp.
	* lto-cgraph.c (LDPR_NUM_KNOWN): Update.
	* ipa.c (varpool_externally_visible_p): IRONLY variables are never
	externally visible.
	* varasm.c (resolution_to_local_definition_p): Add
	LDPR_PREVAILING_DEF_IRONLY_EXP.
	(resolution_local_p): Likewise.

	* common.c (lto_resolution_str): Add new resolution.
	* common.h (lto_resolution_str): Likewise.

From-SVN: r179424

gcc/ChangeLog

+2011-10-02  Jan Hubicka  <jh@suse.cz>
+
+	PR lto/47247
+	* lto-symtab.c (lto_symtab_resolve_symbols): Do not resolve
+	when resolution is already availbale from plugin.
+	(lto_symtab_merge_decls_1): Handle LDPR_PREVAILING_DEF_IRONLY_EXP.
+	* cgraph.c (ld_plugin_symbol_resolution): Add prevailing_def_ironly_exp.
+	* lto-cgraph.c (LDPR_NUM_KNOWN): Update.
+	* ipa.c (varpool_externally_visible_p): IRONLY variables are never
+	externally visible.
+	* varasm.c (resolution_to_local_definition_p): Add
+	LDPR_PREVAILING_DEF_IRONLY_EXP.
+	(resolution_local_p): Likewise.
+
 2011-10-01  David S. Miller  <davem@davemloft.net>
 
 	* config/sparc/sparc.opt (VIS3): New option.

gcc/cgraph.c

@@ -110,7 +110,8 @@ const char * const ld_plugin_symbol_resolution_names[]=
   "preempted_ir",
   "resolved_ir",
   "resolved_exec",
-  "resolved_dyn"
+  "resolved_dyn",
+  "prevailing_def_ironly_exp"
 };
 
 static void cgraph_node_remove_callers (struct cgraph_node *node);

gcc/ipa.c

@@ -685,6 +685,8 @@ varpool_externally_visible_p (struct varpool_node *vnode, bool aliased)
      This is needed for i.e. references from asm statements.   */
   if (varpool_used_from_object_file_p (vnode))
     return true;
+  if (vnode->resolution == LDPR_PREVAILING_DEF_IRONLY)
+    return false;
 
   /* As a special case, the COMDAT virutal tables can be unshared.
      In LTO mode turn vtables into static variables.  The variable is readonly,

gcc/lto-cgraph.c

@@ -52,7 +52,7 @@ static void output_cgraph_opt_summary (cgraph_node_set set);
 static void input_cgraph_opt_summary (VEC (cgraph_node_ptr, heap) * nodes);
 
 /* Number of LDPR values known to GCC.  */
-#define LDPR_NUM_KNOWN (LDPR_RESOLVED_DYN + 1)
+#define LDPR_NUM_KNOWN (LDPR_PREVAILING_DEF_IRONLY_EXP + 1)
 
 /* Cgraph streaming is organized as set of record whose type
    is indicated by a tag.  */

gcc/lto-symtab.c

@@ -441,12 +441,14 @@ lto_symtab_resolve_symbols (void **slot)
 	e->node = cgraph_get_node (e->decl);
       else if (TREE_CODE (e->decl) == VAR_DECL)
 	e->vnode = varpool_get_node (e->decl);
+      if (e->resolution == LDPR_PREVAILING_DEF_IRONLY
+	  || e->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP
+	  || e->resolution == LDPR_PREVAILING_DEF)
+	prevailing = e;
     }
 
-  e = (lto_symtab_entry_t) *slot;
-
   /* If the chain is already resolved there is nothing else to do.  */
-  if (e->resolution != LDPR_UNKNOWN)
+  if (prevailing)
     return;
 
   /* Find the single non-replaceable prevailing symbol and
@@ -586,6 +588,7 @@ lto_symtab_merge_decls_1 (void **slot, void *data ATTRIBUTE_UNUSED)
   for (prevailing = (lto_symtab_entry_t) *slot;
        prevailing
        && prevailing->resolution != LDPR_PREVAILING_DEF_IRONLY
+       && prevailing->resolution != LDPR_PREVAILING_DEF_IRONLY_EXP
        && prevailing->resolution != LDPR_PREVAILING_DEF;
        prevailing = prevailing->next)
     ;
@@ -595,6 +598,7 @@ lto_symtab_merge_decls_1 (void **slot, void *data ATTRIBUTE_UNUSED)
     for (e = prevailing->next; e; e = e->next)
       {
 	if (e->resolution == LDPR_PREVAILING_DEF_IRONLY
+	    || e->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP
 	    || e->resolution == LDPR_PREVAILING_DEF)
 	  fatal_error ("multiple prevailing defs for %qE",
 		       DECL_NAME (prevailing->decl));
@@ -685,9 +689,9 @@ lto_symtab_merge_decls_1 (void **slot, void *data ATTRIBUTE_UNUSED)
      to handle UNKNOWN relocation well.
 
      The problem with storing guessed decision is whether to use
-     PREVAILING_DEF or PREVAILING_DEF_IRONLY.  First one would disable
-     some whole program optimizations, while ther second would imply
-     to many whole program assumptions.  */
+     PREVAILING_DEF, PREVAILING_DEF_IRONLY, PREVAILING_DEF_IRONLY_EXP.
+     First one would disable some whole program optimizations, while
+     ther second would imply to many whole program assumptions.  */
   if (prevailing->node && !flag_ltrans && !prevailing->guessed)
     prevailing->node->resolution = prevailing->resolution;
   else if (prevailing->vnode && !flag_ltrans && !prevailing->guessed)

gcc/lto/ChangeLog

+2011-10-02  Jan Hubicka  <jh@suse.cz>
+
+	PR lto/47247
+	* common.c (lto_resolution_str): Add new resolution.
+	* common.h (lto_resolution_str): Likewise.
+
 2011-09-30  H.J. Lu  <hongjiu.lu@intel.com>
 	    Andi Kleen  <ak@linux.intel.com>
 

gcc/lto/common.c

@@ -31,7 +31,7 @@ const char *lto_visibility_str[4] __attribute__ ((visibility ("hidden"))) =
  "INTERNAL", "HIDDEN"
 };
 
-const char *lto_resolution_str[9] __attribute__ ((visibility ("hidden"))) =
+const char *lto_resolution_str[10] __attribute__ ((visibility ("hidden"))) =
 {
   "UNKNOWN",
   "UNDEF",
@@ -41,6 +41,7 @@ const char *lto_resolution_str[9] __attribute__ ((visibility ("hidden"))) =
   "PREEMPTED_IR",
   "RESOLVED_IR",
   "RESOLVED_EXEC",
-  "RESOLVED_DYN"
+  "RESOLVED_DYN",
+  "PREVAILING_DEF_IRONLY_EXP",
 };
 

gcc/lto/common.h

@@ -20,7 +20,7 @@ along with GCC; see the file COPYING3.  If not see
 
 
 
-static const char *lto_resolution_str[9] =
+static const char *lto_resolution_str[10] =
 {
   "UNKNOWN",
   "UNDEF",
@@ -30,5 +30,6 @@ static const char *lto_resolution_str[9] =
   "PREEMPTED_IR",
   "RESOLVED_IR",
   "RESOLVED_EXEC",
-  "RESOLVED_DYN"
+  "RESOLVED_DYN",
+  "PREVAILING_DEF_IRONLY_EXP",
 };

gcc/varasm.c

@@ -6683,6 +6683,7 @@ static bool
 resolution_to_local_definition_p (enum ld_plugin_symbol_resolution resolution)
 {
   return (resolution == LDPR_PREVAILING_DEF
+	  || resolution == LDPR_PREVAILING_DEF_IRONLY_EXP
 	  || resolution == LDPR_PREVAILING_DEF_IRONLY);
 }
 
@@ -6694,6 +6695,7 @@ resolution_local_p (enum ld_plugin_symbol_resolution resolution)
 {
   return (resolution == LDPR_PREVAILING_DEF
 	  || resolution == LDPR_PREVAILING_DEF_IRONLY
+	  || resolution == LDPR_PREVAILING_DEF_IRONLY_EXP
 	  || resolution == LDPR_PREEMPTED_REG
 	  || resolution == LDPR_PREEMPTED_IR
 	  || resolution == LDPR_RESOLVED_IR

lto-plugin/ChangeLog

+2011-10-02  Jan Hubicka  <jh@suse.cz>
+
+	PR lto/47247
+	* lto-plugin.c (get_symbols_v2): New variable.
+	(write_resolution): Use V2 API when available.
+	(onload): Handle LDPT_GET_SYMBOLS_V2.
+
 2011-09-30  H.J. Lu  <hongjiu.lu@intel.com>
 	    Andi Kleen  <ak@linux.intel.com>
 

lto-plugin/lto-plugin.c

@@ -130,7 +130,7 @@ enum symbol_style
 static char *arguments_file_name;
 static ld_plugin_register_claim_file register_claim_file;
 static ld_plugin_register_all_symbols_read register_all_symbols_read;
-static ld_plugin_get_symbols get_symbols;
+static ld_plugin_get_symbols get_symbols, get_symbols_v2;
 static ld_plugin_register_cleanup register_cleanup;
 static ld_plugin_add_input_file add_input_file;
 static ld_plugin_add_input_library add_input_library;
@@ -443,7 +443,12 @@ write_resolution (void)
       struct plugin_symtab *symtab = &info->symtab;
       struct ld_plugin_symbol *syms = symtab->syms;
 
-      get_symbols (info->handle, symtab->nsyms, syms);
+      /* Version 2 of API supports IRONLY_EXP resolution that is
+         accepted by GCC-4.7 and newer.  */
+      if (get_symbols_v2)
+        get_symbols_v2 (info->handle, symtab->nsyms, syms);
+      else
+        get_symbols (info->handle, symtab->nsyms, syms);
 
       finish_conflict_resolution (symtab, &info->conflicts);
 
@@ -988,6 +993,9 @@ onload (struct ld_plugin_tv *tv)
 	case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK:
 	  register_all_symbols_read = p->tv_u.tv_register_all_symbols_read;
 	  break;
+	case LDPT_GET_SYMBOLS_V2:
+	  get_symbols_v2 = p->tv_u.tv_get_symbols;
+	  break;
 	case LDPT_GET_SYMBOLS:
 	  get_symbols = p->tv_u.tv_get_symbols;
 	  break;