constexpr: overflow checking for integral and floating-point arithmetic.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149473 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 41 insertions, 0 deletions

diff --git a/test/CXX/expr/expr.const/p2-0x.cpp b/test/CXX/expr/expr.const/p2-0x.cpp
index 1355bbb7c2..857f02960f 100644
--- a/test/CXX/expr/expr.const/p2-0x.cpp
+++ b/test/CXX/expr/expr.const/p2-0x.cpp
@@ -196,6 +196,47 @@ namespace UndefinedBehavior {
     C c2;
     constexpr int k4 = c2.f(); // ok!
   }
+
+  namespace Overflow {
+    // Signed int overflow.
+    constexpr int n1 = 2 * 3 * 3 * 7 * 11 * 31 * 151 * 331; // ok
+    constexpr int n2 = 65536 * 32768; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range of }}
+    constexpr int n3 = n1 + 1; // ok
+    constexpr int n4 = n3 + 1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range of }}
+    constexpr int n5 = -65536 * 32768; // ok
+    constexpr int n6 = 3 * -715827883; // expected-error {{constant expression}} expected-note {{value -2147483649 is outside the range of }}
+    constexpr int n7 = -n3 + -1; // ok
+    constexpr int n8 = -1 + n7; // expected-error {{constant expression}} expected-note {{value -2147483649 is outside the range of }}
+    constexpr int n9 = n3 - 0; // ok
+    constexpr int n10 = n3 - -1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range of }}
+    constexpr int n11 = -1 - n3; // ok
+    constexpr int n12 = -2 - n3; // expected-error {{constant expression}} expected-note {{value -2147483649 is outside the range of }}
+    constexpr int n13 = n5 + n5; // expected-error {{constant expression}} expected-note {{value -4294967296 is outside the range of }}
+    constexpr int n14 = n3 - n5; // expected-error {{constant expression}} expected-note {{value 4294967295 is outside the range of }}
+    constexpr int n15 = n5 * n5; // expected-error {{constant expression}} expected-note {{value 4611686018427387904 is outside the range of }}
+    constexpr signed char c1 = 100 * 2; // ok
+    constexpr signed char c2 = '\x64' * '\2'; // also ok
+    constexpr long long ll1 = 0x7fffffffffffffff; // ok
+    constexpr long long ll2 = ll1 + 1; // expected-error {{constant}} expected-note {{ 9223372036854775808 }}
+    constexpr long long ll3 = -ll1 - 1; // ok
+    constexpr long long ll4 = ll3 - 1; // expected-error {{constant}} expected-note {{ -9223372036854775809 }}
+    constexpr long long ll5 = ll3 * ll3; // expected-error {{constant}} expected-note {{ 85070591730234615865843651857942052864 }}
+
+    // Unsigned int overflow.
+    static_assert(65536u * 65536u == 0u, ""); // ok
+    static_assert(4294967295u + 1u == 0u, ""); // ok
+    static_assert(0u - 1u == 4294967295u, ""); // ok
+    static_assert(~0u * ~0u == 1u, ""); // ok
+
+    // Floating-point overflow and NaN.
+    constexpr float f1 = 1e38f * 3.4028f; // ok
+    constexpr float f2 = 1e38f * 3.4029f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}}
+    constexpr float f3 = 1e38f / -.2939f; // ok
+    constexpr float f4 = 1e38f / -.2938f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}}
+    constexpr float f5 = 2e38f + 2e38f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}}
+    constexpr float f6 = -2e38f - 2e38f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}}
+    constexpr float f7 = 0.f / 0.f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces a NaN}}
+  }
 }
 
 // - a lambda-expression (5.1.2);