cgraph.c (cgraph_node::make_local): No name is unique during incremental linking.

	* cgraph.c (cgraph_node::make_local): No name is unique during
	incremental linking.
	* cgraph.h (can_be_discarded_p): Update comment; also common and
	WEAK in named sections can be discarded; when doing incremental
	link do not rely on resolution being the final one.
	* varasm.c (default_binds_local_p_3, decl_binds_to_current_def_p):
	When symbol can be discarded, do not rely on resolution info.
	* symtab.c (symtab_node::nonzero_address): Take into account that
	symbol can be discarded.
	* ipa-visibility.c (update_visibility_by_resolution_info): Handle
	definition correctly.
	(function_and_variable_visibility): Do not set unique_name when
	incrementally linking.

From-SVN: r231050

6 files changed, 58 insertions, 27 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e49fd7a..3f6024e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,19 @@
+2015-11-29  Jan Hubicka  <hubicka@ucw.cz>
+
+	* cgraph.c (cgraph_node::make_local): No name is unique during
+	incremental linking.
+	* cgraph.h (can_be_discarded_p): Update comment; also common and
+	WEAK in named sections can be discarded; when doing incremental
+	link do not rely on resolution being the final one.
+	* varasm.c (default_binds_local_p_3, decl_binds_to_current_def_p):
+	When symbol can be discarded, do not rely on resolution info.
+	* symtab.c (symtab_node::nonzero_address): Take into account that
+	symbol can be discarded.
+	* ipa-visibility.c (update_visibility_by_resolution_info): Handle
+	definition correctly.
+	(function_and_variable_visibility): Do not set unique_name when
+	incrementally linking.
+
 2015-11-29  Nathan Sidwell  <nathan@acm.org>
 
 	* config/nvptx/nvptx.md (const_0_operand, global_mem_operand,
diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index b1228a2..3ee1907 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -2253,8 +2253,9 @@ cgraph_node::make_local (cgraph_node *node, void *)
       node->forced_by_abi = false;
       node->local.local = true;
       node->set_section (NULL);
-      node->unique_name = (node->resolution == LDPR_PREVAILING_DEF_IRONLY
-				  || node->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP);
+      node->unique_name = ((node->resolution == LDPR_PREVAILING_DEF_IRONLY
+			   || node->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
+			   && !flag_incremental_link);
       node->resolution = LDPR_PREVAILING_DEF_IRONLY;
       gcc_assert (node->get_availability () == AVAIL_LOCAL);
     }
diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index b639099..6cff446 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -319,15 +319,23 @@ public:
   /* Return true when there are references to the node.  */
   bool referred_to_p (bool include_self = true);
 
-  /* Return true if NODE can be discarded by linker from the binary.  */
+  /* Return true if symbol can be discarded by linker from the binary.
+     Assume that symbol is used (so there is no need to take into account
+     garbage collecting linkers)
+
+     This can happen for comdats, commons and weaks when they are previaled
+     by other definition at static linking time.  */
   inline bool
   can_be_discarded_p (void)
   {
     return (DECL_EXTERNAL (decl)
-	    || (get_comdat_group ()
-		&& resolution != LDPR_PREVAILING_DEF
-		&& resolution != LDPR_PREVAILING_DEF_IRONLY
-		&& resolution != LDPR_PREVAILING_DEF_IRONLY_EXP));
+	    || ((get_comdat_group ()
+		 || DECL_COMMON (decl)
+		 || (DECL_SECTION_NAME (decl) && DECL_WEAK (decl)))
+		&& ((resolution != LDPR_PREVAILING_DEF
+		     && resolution != LDPR_PREVAILING_DEF_IRONLY_EXP)
+		    || flag_incremental_link)
+		&& resolution != LDPR_PREVAILING_DEF_IRONLY));
   }
 
   /* Return true if NODE is local to a particular COMDAT group, and must not
diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
index 41ed4db..2eab214 100644
--- a/gcc/ipa-visibility.c
+++ b/gcc/ipa-visibility.c
@@ -413,10 +413,10 @@ update_visibility_by_resolution_info (symtab_node * node)
 	    DECL_WEAK (next->decl) = false;
 	    next->set_comdat_group (NULL);
 	  }
-	if (next->externally_visible
-	    && !define)
+	if (!define)
 	  {
-	    DECL_EXTERNAL (next->decl) = true;
+	    if (next->externally_visible)
+	      DECL_EXTERNAL (next->decl) = true;
 	    next->set_comdat_group (NULL);
 	  }
       }
@@ -513,10 +513,10 @@ function_and_variable_visibility (bool whole_program)
 	{
 	  gcc_assert (whole_program || in_lto_p
 		      || !TREE_PUBLIC (node->decl));
-	  node->unique_name = ((node->resolution == LDPR_PREVAILING_DEF_IRONLY
-				|| node->unique_name
-				|| node->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
-				&& TREE_PUBLIC (node->decl));
+	  node->unique_name |= ((node->resolution == LDPR_PREVAILING_DEF_IRONLY
+				 || node->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
+				&& TREE_PUBLIC (node->decl)
+				&& !flag_incremental_link);
 	  node->resolution = LDPR_PREVAILING_DEF_IRONLY;
 	  if (node->same_comdat_group && TREE_PUBLIC (node->decl))
 	    {
@@ -532,10 +532,10 @@ function_and_variable_visibility (bool whole_program)
 		  if (!next->alias)
 		    next->set_section (NULL);
 		  next->make_decl_local ();
-		  next->unique_name = ((next->resolution == LDPR_PREVAILING_DEF_IRONLY
-					|| next->unique_name
-					|| next->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
-				       && TREE_PUBLIC (next->decl));
+		  next->unique_name |= ((next->resolution == LDPR_PREVAILING_DEF_IRONLY
+					 || next->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
+				        && TREE_PUBLIC (next->decl)
+					&& !flag_incremental_link);
 		}
 	      /* cgraph_externally_visible_p has already checked all other nodes
 	         in the group and they will all be made local.  We need to
@@ -657,10 +657,11 @@ function_and_variable_visibility (bool whole_program)
 	  && !vnode->weakref)
 	{
 	  gcc_assert (in_lto_p || whole_program || !TREE_PUBLIC (vnode->decl));
-	  vnode->unique_name = ((vnode->resolution == LDPR_PREVAILING_DEF_IRONLY
-			         || vnode->resolution
+	  vnode->unique_name |= ((vnode->resolution == LDPR_PREVAILING_DEF_IRONLY
+			          || vnode->resolution
 				      == LDPR_PREVAILING_DEF_IRONLY_EXP)
-			        && TREE_PUBLIC (vnode->decl));
+			         && TREE_PUBLIC (vnode->decl)
+				 && !flag_incremental_link);
 	  if (vnode->same_comdat_group && TREE_PUBLIC (vnode->decl))
 	    {
 	      symtab_node *next = vnode;
@@ -675,10 +676,10 @@ function_and_variable_visibility (bool whole_program)
 		  if (!next->alias)
 		    next->set_section (NULL);
 		  next->make_decl_local ();
-		  next->unique_name = ((next->resolution == LDPR_PREVAILING_DEF_IRONLY
-					|| next->unique_name
-					|| next->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
-				       && TREE_PUBLIC (next->decl));
+		  next->unique_name |= ((next->resolution == LDPR_PREVAILING_DEF_IRONLY
+					 || next->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
+				        && TREE_PUBLIC (next->decl)
+					&& !flag_incremental_link);
 		}
 	      vnode->dissolve_same_comdat_group_list ();
 	    }
diff --git a/gcc/symtab.c b/gcc/symtab.c
index 9677131..c188710 100644
--- a/gcc/symtab.c
+++ b/gcc/symtab.c
@@ -1713,6 +1713,7 @@ symtab_node::nonzero_address ()
 	      return true;
 	  if (target->resolution != LDPR_UNKNOWN
 	      && target->resolution != LDPR_UNDEF
+	      && !target->can_be_discarded_p ()
 	      && flag_delete_null_pointer_checks)
 	    return true;
 	  return false;
@@ -1751,6 +1752,7 @@ symtab_node::nonzero_address ()
   /* As the last resort, check the resolution info.  */
   if (resolution != LDPR_UNKNOWN
       && resolution != LDPR_UNDEF
+      && !can_be_discarded_p ()
       && flag_delete_null_pointer_checks)
     return true;
   return false;
diff --git a/gcc/varasm.c b/gcc/varasm.c
index a2adcdb..c4c55e7 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -6837,7 +6837,9 @@ default_binds_local_p_3 (const_tree exp, bool shlib, bool weak_dominate,
     {
       if (node->in_other_partition)
 	defined_locally = true;
-      if (resolution_to_local_definition_p (node->resolution))
+      if (node->can_be_discarded_p ())
+	;
+      else if (resolution_to_local_definition_p (node->resolution))
 	defined_locally = resolved_locally = true;
       else if (resolution_local_p (node->resolution))
 	resolved_locally = true;
@@ -6930,7 +6932,8 @@ decl_binds_to_current_def_p (const_tree decl)
   /* When resolution is available, just use it.  */
   if (symtab_node *node = symtab_node::get (decl))
     {
-      if (node->resolution != LDPR_UNKNOWN)
+      if (node->resolution != LDPR_UNKNOWN
+	  && !node->can_be_discarded_p ())
 	return resolution_to_local_definition_p (node->resolution);
     }