diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 7933e02e57d..90b1671e6f0 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2017-01-26  Jason Merrill  <jason@redhat.com>
+
+	PR c++/79176 - lambda ICE with -flto -Os
+	* decl2.c (vague_linkage_p): Handle decloned 'tors.
+	* tree.c (decl_linkage): Likewise.
+
 2017-01-25  Martin Sebor  <msebor@redhat.com>
 
 	* decl.c (grokdeclarator): Fix a typo in a comment.
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 0a4c5671df1..a9a1d2286a8 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -1816,6 +1816,14 @@ vague_linkage_p (tree decl)
 {
   if (!TREE_PUBLIC (decl))
     {
+      /* maybe_thunk_body clears TREE_PUBLIC on the maybe-in-charge 'tor
+	 variants, check one of the "clones" for the real linkage.  */
+      if ((DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (decl)
+	   || DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (decl))
+	  && DECL_CHAIN (decl)
+	  && DECL_CLONED_FUNCTION (DECL_CHAIN (decl)))
+	return vague_linkage_p (DECL_CHAIN (decl));
+
       gcc_checking_assert (!DECL_COMDAT (decl));
       return false;
     }
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 6fbc99ee56b..3ecc2b00fef 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -4418,6 +4418,14 @@ decl_linkage (tree decl)
   if (TREE_PUBLIC (decl))
     return lk_external;
 
+  /* maybe_thunk_body clears TREE_PUBLIC on the maybe-in-charge 'tor variants,
+     check one of the "clones" for the real linkage.  */
+  if ((DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (decl)
+       || DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (decl))
+      && DECL_CHAIN (decl)
+      && DECL_CLONED_FUNCTION (DECL_CHAIN (decl)))
+    return decl_linkage (DECL_CHAIN (decl));
+
   if (TREE_CODE (decl) == NAMESPACE_DECL)
     return lk_external;
 
diff --git a/gcc/testsuite/g++.dg/opt/declone3.C b/gcc/testsuite/g++.dg/opt/declone3.C
new file mode 100644
index 00000000000..d8c24921116
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/declone3.C
@@ -0,0 +1,16 @@
+// PR c++/79176
+// { dg-do compile { target c++11 } }
+// { dg-options "-flto -Os" }
+
+struct A {};
+struct Object {
+  virtual bool m_fn1();
+  virtual ~Object();
+};
+struct Item : Object, virtual A {
+  ~Item() {
+    [] {};
+  }
+  bool m_fn1();
+};
+bool Item::m_fn1() {}