class.c (emit_register_classes_in_jcr_section): Use DECL_PRESERVE_P instead of mark_decl_referenced.

	* class.c (emit_register_classes_in_jcr_section): Use DECL_PRESERVE_P
	instead of mark_decl_referenced.

	* decl2.c (maybe_make_one_only): Use forced_by_abi instad of
	mark_decl_referenced.
	(mark_needed): Likewise.

	* cgraph.c (cgraph_remove_node): Clear forced_by_abi.
	(cgraph_node_cannot_be_local_p_1): Honnor symbol.forced_by_abi
	and symtab_used_from_object_file_p.
	(cgraph_make_node_local_1): Clear forced_by_abi.
	(cgraph_can_remove_if_no_direct_calls_and): Use forced_by_abi
	* cgraph.h (symtab_node_base): Add forced_by_abi.
	(decide_is_variable_needed): Remove.
	(varpool_can_remove_if_no_refs): Honnor symbol.forced_by_abi.
	* cgraphunit.c (cgraph_decide_is_function_needed): Rename to ..
	(decide_is_symbol_needed): ... this one; handle symbols in general;
	always analyze virtuals; honnor forced_by_abi.
	(cgraph_finalize_function): Update.
	(varpool_finalize_decl): Update.
	(symbol_defined_and_needed): Remove.
	(analyze_functions): Update.
	* lto-cgraph.c (lto_output_node, lto_output_varpool_node,
	output_refs, input_overwrite_node): Handle forced_by_abi.
	* ipa.c (cgraph_address_taken_from_non_vtable_p): Rename to ...
	(address_taken_from_non_vtable_p): ... this one.
	(comdat_can_be_unshared_p_1): New function.
	(cgraph_comdat_can_be_unshared_p): Rename to ...
	(comdat_can_be_unshared_p): ... this one; handle symbols in general.
	(varpool_externally_visible_p): Use comdat_can_be_unshared_p.
	(function_and_variable_visibility): Clear forced_by_abi as needed.
	* trans-mem.c (ipa_tm_mark_forced_by_abi_node): New functoin.
	(ipa_tm_create_version_alias, ipa_tm_create_version): Update.
	* varasm.c (mark_decl_referenced): Remove.
	* symtab.c (dump_symtab_base): Dump forced_by_abi.
	* varpool.c (decide_is_variable_needed): Remove.

From-SVN: r199695

1 files changed, 56 insertions, 19 deletions

diff --git a/gcc/ipa.c b/gcc/ipa.c
index 443d737..a73cbb1 100644
--- a/gcc/ipa.c
+++ b/gcc/ipa.c
@@ -519,7 +519,7 @@ ipa_discover_readonly_nonaddressable_vars (void)
 
 /* Return true when there is a reference to node and it is not vtable.  */
 static bool
-cgraph_address_taken_from_non_vtable_p (struct cgraph_node *node)
+address_taken_from_non_vtable_p (symtab_node node)
 {
   int i;
   struct ipa_ref *ref;
@@ -537,6 +537,38 @@ cgraph_address_taken_from_non_vtable_p (struct cgraph_node *node)
   return false;
 }
 
+/* A helper for comdat_can_be_unshared_p.  */
+
+static bool
+comdat_can_be_unshared_p_1 (symtab_node node)
+{
+  /* When address is taken, we don't know if equality comparison won't
+     break eventaully. Exception are virutal functions and vtables, where
+     this is not possible by language standard.  */
+  if (!DECL_VIRTUAL_P (node->symbol.decl)
+      && address_taken_from_non_vtable_p (node))
+    return false;
+
+  /* If the symbol is used in some weird way, better to not touch it.  */
+  if (node->symbol.force_output)
+    return false;
+
+  /* Explicit instantiations needs to be output when possibly
+     used externally.  */
+  if (node->symbol.forced_by_abi
+      && TREE_PUBLIC (node->symbol.decl)
+      && (node->symbol.resolution != LDPR_PREVAILING_DEF_IRONLY
+          && !flag_whole_program))
+    return false;
+
+  /* Non-readonly and volatile variables can not be duplicated.  */
+  if (is_a <varpool_node> (node)
+      && (!TREE_READONLY (node->symbol.decl)
+	  || TREE_THIS_VOLATILE (node->symbol.decl)))
+    return false;
+  return true;
+}
+
 /* COMDAT functions must be shared only if they have address taken,
    otherwise we can produce our own private implementation with
    -fwhole-program.  
@@ -547,24 +579,21 @@ cgraph_address_taken_from_non_vtable_p (struct cgraph_node *node)
    but in C++ there is no way to compare their addresses for equality.  */
 
 static bool
-cgraph_comdat_can_be_unshared_p (struct cgraph_node *node)
+comdat_can_be_unshared_p (symtab_node node)
 {
-  if ((cgraph_address_taken_from_non_vtable_p (node)
-       && !DECL_VIRTUAL_P (node->symbol.decl))
-      || !node->symbol.definition)
+  if (!comdat_can_be_unshared_p_1 (node))
     return false;
   if (node->symbol.same_comdat_group)
     {
-      struct cgraph_node *next;
+      symtab_node next;
 
       /* If more than one function is in the same COMDAT group, it must
          be shared even if just one function in the comdat group has
          address taken.  */
-      for (next = cgraph (node->symbol.same_comdat_group);
-	   next != node; next = cgraph (next->symbol.same_comdat_group))
-	if (cgraph_address_taken_from_non_vtable_p (next)
-	    && !DECL_VIRTUAL_P (next->symbol.decl))
-	  return false;
+      for (next = node->symbol.same_comdat_group;
+	   next != node; next = next->symbol.same_comdat_group)
+        if (!comdat_can_be_unshared_p_1 (next))
+          return false;
     }
   return true;
 }
@@ -610,7 +639,7 @@ cgraph_externally_visible_p (struct cgraph_node *node,
       implementing same COMDAT)  */
   if ((in_lto_p || whole_program)
       && DECL_COMDAT (node->symbol.decl)
-      && cgraph_comdat_can_be_unshared_p (node))
+      && comdat_can_be_unshared_p ((symtab_node) node))
     return false;
 
   /* When doing link time optimizations, hidden symbols become local.  */
@@ -680,8 +709,8 @@ varpool_externally_visible_p (struct varpool_node *vnode)
      is faster for dynamic linking.  Also this match logic hidding vtables
      from LTO symbol tables.  */
   if ((in_lto_p || flag_whole_program)
-      && !vnode->symbol.force_output
-      && DECL_COMDAT (vnode->symbol.decl) && DECL_VIRTUAL_P (vnode->symbol.decl))
+      && DECL_COMDAT (vnode->symbol.decl)
+      && comdat_can_be_unshared_p ((symtab_node) vnode))
     return false;
 
   /* When doing link time optimizations, hidden symbols become local.  */
@@ -743,9 +772,11 @@ function_and_variable_visibility (bool whole_program)
       /* Frontends and alias code marks nodes as needed before parsing is finished.
 	 We may end up marking as node external nodes where this flag is meaningless
 	 strip it.  */
-      if (node->symbol.force_output
-	  && (DECL_EXTERNAL (node->symbol.decl) || !node->symbol.definition))
-	node->symbol.force_output = 0;
+      if (DECL_EXTERNAL (node->symbol.decl) || !node->symbol.definition)
+	{
+	  node->symbol.force_output = 0;
+	  node->symbol.forced_by_abi = 0;
+	}
 
       /* C++ FE on lack of COMDAT support create local COMDAT functions
 	 (that ought to be shared but can not due to object format
@@ -780,7 +811,10 @@ function_and_variable_visibility (bool whole_program)
 	  node->symbol.externally_visible = true;
 	}
       else
-	node->symbol.externally_visible = false;
+	{
+	  node->symbol.externally_visible = false;
+	  node->symbol.forced_by_abi = false;
+	}
       if (!node->symbol.externally_visible && node->symbol.definition
 	  && !DECL_EXTERNAL (node->symbol.decl))
 	{
@@ -859,7 +893,10 @@ function_and_variable_visibility (bool whole_program)
       if (varpool_externally_visible_p (vnode))
 	vnode->symbol.externally_visible = true;
       else
-        vnode->symbol.externally_visible = false;
+	{
+          vnode->symbol.externally_visible = false;
+	  vnode->symbol.forced_by_abi = false;
+	}
       if (!vnode->symbol.externally_visible)
 	{
 	  gcc_assert (in_lto_p || whole_program || !TREE_PUBLIC (vnode->symbol.decl));