[libcxx] Fix max_size() across all containers

Summary: The `max_size()` method of containers should respect both the allocator's reported `max_size` and the range of the `difference_type`. This patch makes all containers choose the smallest of those two values.

Reviewers: mclow.lists, EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D26885

llvm-svn: 287729

1 files changed, 27 insertions, 11 deletions

diff --git a/libcxx/test/std/containers/associative/map/map.access/max_size.pass.cpp b/libcxx/test/std/containers/associative/map/map.access/max_size.pass.cpp
index c67d8b1f674..82a817a1f4a 100644
--- a/libcxx/test/std/containers/associative/map/map.access/max_size.pass.cpp
+++ b/libcxx/test/std/containers/associative/map/map.access/max_size.pass.cpp
@@ -13,23 +13,39 @@
 
 // size_type max_size() const;
 
-#include <map>
 #include <cassert>
+#include <limits>
+#include <map>
+#include <type_traits>
 
-#include "min_allocator.h"
+#include "test_allocator.h"
+#include "test_macros.h"
 
 int main()
 {
-    {
-    typedef std::map<int, double> M;
-    M m;
-    assert(m.max_size() != 0);
+  typedef std::pair<const int, int> KV;
+  {
+    typedef limited_allocator<KV, 10> A;
+    typedef std::map<int, int, std::less<int>, A> C;
+    C c;
+    assert(c.max_size() <= 10);
+    LIBCPP_ASSERT(c.max_size() == 10);
+  }
+  {
+    typedef limited_allocator<KV, (size_t)-1> A;
+    typedef std::map<int, int, std::less<int>, A> C;
+    const C::difference_type max_dist =
+        std::numeric_limits<C::difference_type>::max();
+    C c;
+    assert(c.max_size() <= max_dist);
+    LIBCPP_ASSERT(c.max_size() == max_dist);
     }
-#if TEST_STD_VER >= 11
     {
-    typedef std::map<int, double, std::less<int>, min_allocator<std::pair<const int, double>>> M;
-    M m;
-    assert(m.max_size() != 0);
+      typedef std::map<char, int> C;
+      const C::difference_type max_dist =
+          std::numeric_limits<C::difference_type>::max();
+      C c;
+      assert(c.max_size() <= max_dist);
+      assert(c.max_size() <= alloc_max_size(c.get_allocator()));
     }
-#endif
 }