PR c++/80916 - spurious "static but not defined" warning.

Nothing can refer to an internal decl with no definition, so we shouldn't
treat such a decl as a possible devirtualization target.

	* gimple-fold.c (can_refer_decl_in_current_unit_p): Return false
	for an internal symbol with DECL_EXTERNAL.

From-SVN: r269459

1 files changed, 16 insertions, 0 deletions

diff --git a/gcc/testsuite/g++.dg/warn/unused-fn1.C b/gcc/testsuite/g++.dg/warn/unused-fn1.C
new file mode 100644
index 0000000..aabc01b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/unused-fn1.C
@@ -0,0 +1,16 @@
+// PR c++/80916
+// { dg-options "-Os -Wunused" }
+
+struct j {
+  virtual void dispatch(void *) {}
+};
+template <typename>
+struct i : j {
+  void dispatch(void *) {} // warning: 'void i< <template-parameter-1-1> >::dispatch(void*) [with <template-parameter-1-1> = {anonymous}::l]' declared 'static' but never defined [-Wunused-function]
+};
+namespace {
+  struct l : i<l> {};
+}
+void f(j *k) {
+  k->dispatch(0);
+}