Introduce llless(), and use it for llmin(), llmax().

Add tests to verify that llless() correctly handles signed <=> unsigned
comparison, which native "<" does not.

1 files changed, 75 insertions, 0 deletions

diff --git a/indra/llcommon/tests/llcond_test.cpp b/indra/llcommon/tests/llcond_test.cpp
index f2a302ed13..7d1ac6edb9 100644
--- a/indra/llcommon/tests/llcond_test.cpp
+++ b/indra/llcommon/tests/llcond_test.cpp
@@ -19,6 +19,7 @@
 // other Linden headers
 #include "../test/lltut.h"
 #include "llcoros.h"
+#include "lldefs.h"                 // llless()
 
 /*****************************************************************************
 *   TUT
@@ -64,4 +65,78 @@ namespace tut
         cond.set_all(2);
         cond.wait_equal(3);
     }
+
+    template <typename T0, typename T1>
+    struct compare
+    {
+        const char* desc;
+        T0 lhs;
+        T1 rhs;
+        bool expect;
+
+        void test() const
+        {
+            // fails
+//          ensure_equals(desc, (lhs <  rhs), expect);
+            ensure_equals(desc, llless(lhs, rhs), expect);
+        }
+    };
+
+    template<> template<>
+    void object::test<3>()
+    {
+        set_test_name("comparison");
+        // Try to construct signed and unsigned variables such that the
+        // compiler can't optimize away the code to compare at runtime.
+        std::istringstream input("-1 10 20 10 20");
+        int minus1, s10, s20;
+        input >> minus1 >> s10 >> s20;
+        unsigned u10, u20;
+        input >> u10 >> u20;
+        ensure_equals("minus1 wrong", minus1, -1);
+        ensure_equals("s10 wrong", s10, 10);
+        ensure_equals("s20 wrong", s20, 20);
+        ensure_equals("u10 wrong", u10, 10);
+        ensure_equals("u20 wrong", u20, 20);
+        // signed < signed should always work!
+        compare<int, int> ss[] =
+            { {"minus1 < s10", minus1, s10, true},
+              {"s10 < s10", s10, s10, false},
+              {"s20 < s10", s20, s20, false}
+            };
+        for (const auto& cmp : ss)
+        {
+            cmp.test();
+        }
+        // unsigned < unsigned should always work!
+        compare<unsigned, unsigned> uu[] =
+            { {"u10 < u20", u10, u20, true},
+              {"u20 < u20", u20, u20, false},
+              {"u20 < u10", u20, u10, false}
+            };
+        for (const auto& cmp : uu)
+        {
+            cmp.test();
+        }
+        // signed < unsigned ??
+        compare<int, unsigned> su[] =
+            { {"minus1 < u10", minus1, u10, true},
+              {"s10 < u10", s10, u10, false},
+              {"s20 < u10", s20, u10, false}
+            };
+        for (const auto& cmp : su)
+        {
+            cmp.test();
+        }
+        // unsigned < signed ??
+        compare<unsigned, int> us[] =
+            { {"u10 < minus1", u10, minus1, false},
+              {"u10 < s10", u10, s10, false},
+              {"u10 < s20", u10, s20, true}
+            };
+        for (const auto& cmp : us)
+        {
+            cmp.test();
+        }
+    }
 } // namespace tut