C++1y: support for increment and decrement in constant expression evaluation.
llvm-svn: 181173
diff --git a/clang/test/SemaCXX/constant-expression-cxx1y.cpp b/clang/test/SemaCXX/constant-expression-cxx1y.cpp
index 62739ee..2dfded4 100644
--- a/clang/test/SemaCXX/constant-expression-cxx1y.cpp
+++ b/clang/test/SemaCXX/constant-expression-cxx1y.cpp
@@ -161,11 +161,9 @@
swap(*begin++, *end);
#else
if (begin != end) {
- end = end - 1;
- if (begin == end)
+ if (begin == --end)
return;
- swap(*begin, *end);
- begin = begin + 1;
+ swap(*begin++, *end);
reverse(begin, end);
}
#endif
@@ -180,10 +178,8 @@
}
#else
if (a != ae && b != be) {
- if (*a != *b)
+ if (*a++ != *b++)
return false;
- a = a + 1;
- b = b + 1;
return equal(a, ae, b, be);
}
#endif
@@ -286,3 +282,73 @@
}
static_assert(test(0), ""); // expected-error {{constant expression}} expected-note {{in call}}
}
+
+namespace incdec {
+ template<typename T> constexpr T &ref(T &&r) { return r; }
+ template<typename T> constexpr T postinc(T &&r) { return (r++, r); }
+ template<typename T> constexpr T postdec(T &&r) { return (r--, r); }
+
+ static_assert(++ref(0) == 1, "");
+ static_assert(ref(0)++ == 0, "");
+ static_assert(postinc(0) == 1, "");
+ static_assert(--ref(0) == -1, "");
+ static_assert(ref(0)-- == 0, "");
+ static_assert(postdec(0) == -1, "");
+
+ constexpr int overflow_int_inc_1 = ref(0x7fffffff)++; // expected-error {{constant}} expected-note {{2147483648}}
+ constexpr int overflow_int_inc_1_ok = ref(0x7ffffffe)++;
+ constexpr int overflow_int_inc_2 = ++ref(0x7fffffff); // expected-error {{constant}} expected-note {{2147483648}}
+ constexpr int overflow_int_inc_2_ok = ++ref(0x7ffffffe);
+
+ // inc/dec on short can't overflow because we promote to int first
+ static_assert(++ref<short>(0x7fff) == (int)0xffff8000u, "");
+ static_assert(--ref<short>(0x8000) == 0x7fff, "");
+
+ // inc on bool sets to true
+ static_assert(++ref(false), ""); // expected-warning {{deprecated}}
+ static_assert(++ref(true), ""); // expected-warning {{deprecated}}
+
+ int arr[10];
+ static_assert(++ref(&arr[0]) == &arr[1], "");
+ static_assert(++ref(&arr[9]) == &arr[10], "");
+ static_assert(++ref(&arr[10]) == &arr[11], ""); // expected-error {{constant}} expected-note {{cannot refer to element 11}}
+ static_assert(ref(&arr[0])++ == &arr[0], "");
+ static_assert(ref(&arr[10])++ == &arr[10], ""); // expected-error {{constant}} expected-note {{cannot refer to element 11}}
+ static_assert(postinc(&arr[0]) == &arr[1], "");
+ static_assert(--ref(&arr[10]) == &arr[9], "");
+ static_assert(--ref(&arr[1]) == &arr[0], "");
+ static_assert(--ref(&arr[0]) != &arr[0], ""); // expected-error {{constant}} expected-note {{cannot refer to element -1}}
+ static_assert(ref(&arr[1])-- == &arr[1], "");
+ static_assert(ref(&arr[0])-- == &arr[0], ""); // expected-error {{constant}} expected-note {{cannot refer to element -1}}
+ static_assert(postdec(&arr[1]) == &arr[0], "");
+
+ int x;
+ static_assert(++ref(&x) == &x + 1, "");
+
+ static_assert(++ref(0.0) == 1.0, "");
+ static_assert(ref(0.0)++ == 0.0, "");
+ static_assert(postinc(0.0) == 1.0, "");
+ static_assert(--ref(0.0) == -1.0, "");
+ static_assert(ref(0.0)-- == 0.0, "");
+ static_assert(postdec(0.0) == -1.0, "");
+
+ static_assert(++ref(1e100) == 1e100, "");
+ static_assert(--ref(1e100) == 1e100, "");
+
+ union U {
+ int a, b;
+ };
+ constexpr int f(U u) {
+ return ++u.b; // expected-note {{increment of member 'b' of union with active member 'a'}}
+ }
+ constexpr int wrong_member = f({0}); // expected-error {{constant}} expected-note {{in call to 'f({.a = 0})'}}
+ constexpr int vol = --ref<volatile int>(0); // expected-error {{constant}} expected-note {{decrement of volatile-qualified}}
+
+ constexpr int incr(int k) {
+ int x = k;
+ if (x++ == 100)
+ return x;
+ return incr(x);
+ }
+ static_assert(incr(0) == 101, "");
+}