Another C++ PATCH for c++/61659 (DECL_COMDAT and devirt)

[Jason Merrill]

After

        * decl.c (maybe_commonize_var): Don't use DECL_COMDAT to trigger
        comdat_linkage.
targets without weak symbol support started getting link errors 
bootstrapping GCC.  This ought to fix that.

Tested x86_64-pc-linux-gnu, applying to trunk.
commit e3859ec10649526a24b439301db79a34d7b90ba3
Author: Jason Merrill <ja...@redhat.com>
Date:   Tue Sep 9 12:21:03 2014 -0400

    	PR c++/61659
    	* decl.c (grokfndecl): Don't set DECL_COMDAT on static inlines.
    	(duplicate_decls, start_decl): Likewise.
    	* pt.c (check_explicit_specialization): Likewise.
    	(push_template_decl_real): Or static templates.

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index d8fb35e..6e195bb 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -2215,7 +2215,8 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
 		      olddecl);
 
 	  SET_DECL_TEMPLATE_SPECIALIZATION (olddecl);
-	  DECL_COMDAT (newdecl) = DECL_DECLARED_INLINE_P (newdecl);
+	  DECL_COMDAT (newdecl) = (TREE_PUBLIC (newdecl)
+				   && DECL_DECLARED_INLINE_P (newdecl));
 
 	  /* Don't propagate visibility from the template to the
 	     specialization here.  We'll do that in determine_visibility if
@@ -4718,7 +4719,8 @@ start_decl (const cp_declarator *declarator,
 	{
 	  SET_DECL_TEMPLATE_SPECIALIZATION (decl);
 	  if (TREE_CODE (decl) == FUNCTION_DECL)
-	    DECL_COMDAT (decl) = DECL_DECLARED_INLINE_P (decl);
+	    DECL_COMDAT (decl) = (TREE_PUBLIC (decl)
+				  && DECL_DECLARED_INLINE_P (decl));
 	  else
 	    DECL_COMDAT (decl) = false;
 
@@ -7699,7 +7701,8 @@ grokfndecl (tree ctype,
   if (inlinep)
     {
       DECL_DECLARED_INLINE_P (decl) = 1;
-      DECL_COMDAT (decl) = 1;
+      if (publicp)
+	DECL_COMDAT (decl) = 1;
     }
   if (inlinep & 2)
     DECL_DECLARED_CONSTEXPR_P (decl) = true;
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 44569e2..3c93178 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -2813,7 +2813,8 @@ check_explicit_specialization (tree declarator,
 	    SET_DECL_IMPLICIT_INSTANTIATION (decl);
 	  else if (TREE_CODE (decl) == FUNCTION_DECL)
 	    /* A specialization is not necessarily COMDAT.  */
-	    DECL_COMDAT (decl) = DECL_DECLARED_INLINE_P (decl);
+	    DECL_COMDAT (decl) = (TREE_PUBLIC (decl)
+				  && DECL_DECLARED_INLINE_P (decl));
 	  else if (TREE_CODE (decl) == VAR_DECL)
 	    DECL_COMDAT (decl) = false;
 
@@ -5059,6 +5060,7 @@ template arguments to %qD do not match original template %qD",
 
   if (flag_implicit_templates
       && !is_friend
+      && TREE_PUBLIC (decl)
       && VAR_OR_FUNCTION_DECL_P (decl))
     /* Set DECL_COMDAT on template instantiations; if we force
        them to be emitted by explicit instantiation or -frepo,
diff --git a/gcc/testsuite/g++.dg/abi/no-weak1.C b/gcc/testsuite/g++.dg/abi/no-weak1.C
new file mode 100644
index 0000000..663643f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/no-weak1.C
@@ -0,0 +1,21 @@
+// { dg-options "-fno-weak" }
+// { dg-final { scan-assembler "local\[ \t\]*_ZZL1fvE1i" { target x86_64-*-*gnu } } }
+// { dg-final { scan-assembler "local\[ \t\]*_ZZ1gIiEvvE1i" { target x86_64-*-*gnu } } }
+
+static inline void f()
+{
+  static int i;
+  ++i;
+};
+
+template <class T> static void g()
+{
+  static int i;
+  ++i;
+}
+
+int main()
+{
+  f();
+  g<int>();
+}