Fix PR31489 - std::function self-swap segfaults

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@290721 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/copy_assign.pass.cpp

@@ -19,92 +19,120 @@
 #include "test_macros.h"
 #include "count_new.hpp"
 
-class A
-{
-    int data_[10];
+class A {
+  int data_[10];
+
 public:
-    static int count;
+  static int count;
 
-    A()
-    {
-        ++count;
-        for (int i = 0; i < 10; ++i)
-            data_[i] = i;
-    }
+  A() {
+    ++count;
+    for (int i = 0; i < 10; ++i)
+      data_[i] = i;
+  }
 
-    A(const A&) {++count;}
+  A(const A &) { ++count; }
 
-    ~A() {--count;}
+  ~A() { --count; }
 
-    int operator()(int i) const
-    {
-        for (int j = 0; j < 10; ++j)
-            i += data_[j];
-        return i;
-    }
+  int operator()(int i) const {
+    for (int j = 0; j < 10; ++j)
+      i += data_[j];
+    return i;
+  }
 };
 
 int A::count = 0;
 
-int g(int) {return 0;}
+int g0() { return 0; }
+int g(int) { return 0; }
+int g2(int, int) { return 2; }
+int g3(int, int, int) { return 3; }
 
-int main()
-{
-    assert(globalMemCounter.checkOutstandingNewEq(0));
-    {
+int main() {
+  assert(globalMemCounter.checkOutstandingNewEq(0));
+  {
     std::function<int(int)> f = A();
     assert(A::count == 1);
     assert(globalMemCounter.checkOutstandingNewEq(1));
     assert(f.target<A>());
-    assert(f.target<int(*)(int)>() == 0);
+    assert(f.target<int (*)(int)>() == 0);
     std::function<int(int)> f2;
     f2 = f;
     assert(A::count == 2);
     assert(globalMemCounter.checkOutstandingNewEq(2));
     assert(f2.target<A>());
-    assert(f2.target<int(*)(int)>() == 0);
-    }
-    assert(A::count == 0);
-    assert(globalMemCounter.checkOutstandingNewEq(0));
-    {
+    assert(f2.target<int (*)(int)>() == 0);
+  }
+  assert(A::count == 0);
+  assert(globalMemCounter.checkOutstandingNewEq(0));
+  {
     std::function<int(int)> f = g;
     assert(globalMemCounter.checkOutstandingNewEq(0));
-    assert(f.target<int(*)(int)>());
+    assert(f.target<int (*)(int)>());
     assert(f.target<A>() == 0);
     std::function<int(int)> f2;
     f2 = f;
     assert(globalMemCounter.checkOutstandingNewEq(0));
-    assert(f2.target<int(*)(int)>());
+    assert(f2.target<int (*)(int)>());
     assert(f2.target<A>() == 0);
-    }
-    assert(globalMemCounter.checkOutstandingNewEq(0));
-    {
+  }
+  assert(globalMemCounter.checkOutstandingNewEq(0));
+  {
     std::function<int(int)> f;
     assert(globalMemCounter.checkOutstandingNewEq(0));
-    assert(f.target<int(*)(int)>() == 0);
+    assert(f.target<int (*)(int)>() == 0);
     assert(f.target<A>() == 0);
     std::function<int(int)> f2;
     f2 = f;
     assert(globalMemCounter.checkOutstandingNewEq(0));
-    assert(f2.target<int(*)(int)>() == 0);
+    assert(f2.target<int (*)(int)>() == 0);
     assert(f2.target<A>() == 0);
-    }
+  }
+  {
+    typedef std::function<int()> Func;
+    Func f = g0;
+    Func& fr = (f = f);
+    assert(&fr == &f);
+    assert(*f.target<int(*)()>() == g0);
+  }
+  {
+    typedef std::function<int(int)> Func;
+    Func f = g;
+    Func& fr = (f = f);
+    assert(&fr == &f);
+    assert(*f.target<int(*)(int)>() == g);
+  }
+  {
+    typedef std::function<int(int, int)> Func;
+    Func f = g2;
+    Func& fr = (f = f);
+    assert(&fr == &f);
+    assert(*f.target<int(*)(int, int)>() == g2);
+  }
+  {
+    typedef std::function<int(int, int, int)> Func;
+    Func f = g3;
+    Func& fr = (f = f);
+    assert(&fr == &f);
+    assert(*f.target<int(*)(int, int, int)>() == g3);
+  }
 #if TEST_STD_VER >= 11
-    assert(globalMemCounter.checkOutstandingNewEq(0));
-    {
+  assert(globalMemCounter.checkOutstandingNewEq(0));
+  {
     std::function<int(int)> f = A();
     assert(A::count == 1);
     assert(globalMemCounter.checkOutstandingNewEq(1));
     assert(f.target<A>());
-    assert(f.target<int(*)(int)>() == 0);
+    assert(f.target<int (*)(int)>() == 0);
     std::function<int(int)> f2;
     f2 = std::move(f);
     assert(A::count == 1);
     assert(globalMemCounter.checkOutstandingNewEq(1));
     assert(f2.target<A>());
-    assert(f2.target<int(*)(int)>() == 0);
+    assert(f2.target<int (*)(int)>() == 0);
     assert(f.target<A>() == 0);
-    assert(f.target<int(*)(int)>() == 0);
-    }
+    assert(f.target<int (*)(int)>() == 0);
+  }
 #endif
 }