On targets without alias support (Darwin) bootstrap was failing with a
warning about one of the constructor clones being unused. We shouldn't
warn about that, since clones are artificial; we should only warn if the
abstract constructor is unused.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit 16232674086f330d05f7279681978eb683990ed5
Author: Jason Merrill <ja...@redhat.com>
Date: Tue Jun 9 10:12:47 2015 -0400
PR bootstrap/66448
* toplev.c (check_global_declaration): Don't warn about a clone.
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-function1.C b/gcc/testsuite/g++.dg/warn/Wunused-function1.C
new file mode 100644
index 0000000..86b319a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-function1.C
@@ -0,0 +1,12 @@
+// PR bootstrap/66448
+// { dg-options "-Wunused-function" }
+
+struct A { A(); };
+namespace {
+ struct B: virtual A { B(); };
+ B::B() { }
+ B b;
+
+ struct C: virtual A { C(); };
+ C::C() { } // { dg-warning "defined but not used" }
+}
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 306d008..b1ccc18 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -529,6 +529,7 @@ check_global_declaration (tree decl)
&& ! (DECL_NAME (decl) && TREE_USED (DECL_NAME (decl)))
&& ! DECL_EXTERNAL (decl)
&& ! DECL_ARTIFICIAL (decl)
+ && ! DECL_ABSTRACT_ORIGIN (decl)
&& ! TREE_PUBLIC (decl)
/* A volatile variable might be used in some non-obvious way. */
&& ! TREE_THIS_VOLATILE (decl)
