You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
116 lines
4.4 KiB
116 lines
4.4 KiB
// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -Wno-unused %s
|
|
|
|
int f(int, int = 0);
|
|
|
|
struct A {
|
|
int x, y;
|
|
};
|
|
struct S {
|
|
S(int, int);
|
|
int n;
|
|
};
|
|
|
|
void test() {
|
|
int a;
|
|
int xs[10];
|
|
++a = 0; // ok
|
|
a + ++a; // expected-warning {{unsequenced modification and access to 'a'}}
|
|
a = ++a; // ok
|
|
a + a++; // expected-warning {{unsequenced modification and access to 'a'}}
|
|
a = a++; // expected-warning {{multiple unsequenced modifications to 'a'}}
|
|
++ ++a; // ok
|
|
(a++, a++); // ok
|
|
++a + ++a; // expected-warning {{multiple unsequenced modifications to 'a'}}
|
|
a++ + a++; // expected-warning {{multiple unsequenced modifications}}
|
|
(a++, a) = 0; // ok, increment is sequenced before value computation of LHS
|
|
a = xs[++a]; // ok
|
|
a = xs[a++]; // expected-warning {{multiple unsequenced modifications}}
|
|
(a ? xs[0] : xs[1]) = ++a; // expected-warning {{unsequenced modification and access}}
|
|
a = (++a, ++a); // ok
|
|
a = (a++, ++a); // ok
|
|
a = (a++, a++); // expected-warning {{multiple unsequenced modifications}}
|
|
f(a, a); // ok
|
|
f(a = 0, a); // expected-warning {{unsequenced modification and access}}
|
|
f(a, a += 0); // expected-warning {{unsequenced modification and access}}
|
|
f(a = 0, a = 0); // expected-warning {{multiple unsequenced modifications}}
|
|
a = f(++a); // ok
|
|
a = f(a++); // ok
|
|
a = f(++a, a++); // expected-warning {{multiple unsequenced modifications}}
|
|
|
|
// Compound assignment "A OP= B" is equivalent to "A = A OP B" except that A
|
|
// is evaluated only once.
|
|
(++a, a) = 1; // ok
|
|
(++a, a) += 1; // ok
|
|
a = ++a; // ok
|
|
a += ++a; // expected-warning {{unsequenced modification and access}}
|
|
|
|
A agg1 = { a++, a++ }; // ok
|
|
A agg2 = { a++ + a, a++ }; // expected-warning {{unsequenced modification and access}}
|
|
|
|
S str1(a++, a++); // expected-warning {{multiple unsequenced modifications}}
|
|
S str2 = { a++, a++ }; // ok
|
|
S str3 = { a++ + a, a++ }; // expected-warning {{unsequenced modification and access}}
|
|
|
|
struct Z { A a; S s; } z = { { ++a, ++a }, { ++a, ++a } }; // ok
|
|
a = S { ++a, a++ }.n; // ok
|
|
A { ++a, a++ }.x; // ok
|
|
a = A { ++a, a++ }.x; // expected-warning {{unsequenced modifications}}
|
|
A { ++a, a++ }.x + A { ++a, a++ }.y; // expected-warning {{unsequenced modifications}}
|
|
|
|
(xs[2] && (a = 0)) + a; // ok
|
|
(0 && (a = 0)) + a; // ok
|
|
(1 && (a = 0)) + a; // expected-warning {{unsequenced modification and access}}
|
|
|
|
(xs[3] || (a = 0)) + a; // ok
|
|
(0 || (a = 0)) + a; // expected-warning {{unsequenced modification and access}}
|
|
(1 || (a = 0)) + a; // ok
|
|
|
|
(xs[4] ? a : ++a) + a; // ok
|
|
(0 ? a : ++a) + a; // expected-warning {{unsequenced modification and access}}
|
|
(1 ? a : ++a) + a; // ok
|
|
(0 ? a : a++) + a; // expected-warning {{unsequenced modification and access}}
|
|
(1 ? a : a++) + a; // ok
|
|
(xs[5] ? ++a : ++a) + a; // FIXME: warn here
|
|
|
|
(++a, xs[6] ? ++a : 0) + a; // expected-warning {{unsequenced modification and access}}
|
|
|
|
// Here, the read of the fourth 'a' might happen before or after the write to
|
|
// the second 'a'.
|
|
a += (a++, a) + a; // expected-warning {{unsequenced modification and access}}
|
|
|
|
int *p = xs;
|
|
a = *(a++, p); // ok
|
|
a = a++ && a; // ok
|
|
|
|
A *q = &agg1;
|
|
(q = &agg2)->y = q->x; // expected-warning {{unsequenced modification and access to 'q'}}
|
|
|
|
// This has undefined behavior if a == 0; otherwise, the side-effect of the
|
|
// increment is sequenced before the value computation of 'f(a, a)', which is
|
|
// sequenced before the value computation of the '&&', which is sequenced
|
|
// before the assignment. We treat the sequencing in '&&' as being
|
|
// unconditional.
|
|
a = a++ && f(a, a);
|
|
|
|
// This has undefined behavior if a != 0. FIXME: We should diagnose this.
|
|
(a && a++) + a;
|
|
|
|
(xs[7] && ++a) * (!xs[7] && ++a); // ok
|
|
|
|
xs[0] = (a = 1, a); // ok
|
|
(a -= 128) &= 128; // ok
|
|
++a += 1; // ok
|
|
|
|
xs[8] ? ++a + a++ : 0; // expected-warning {{multiple unsequenced modifications}}
|
|
xs[8] ? 0 : ++a + a++; // expected-warning {{multiple unsequenced modifications}}
|
|
xs[8] ? ++a : a++; // ok
|
|
|
|
xs[8] && (++a + a++); // expected-warning {{multiple unsequenced modifications}}
|
|
xs[8] || (++a + a++); // expected-warning {{multiple unsequenced modifications}}
|
|
|
|
(__builtin_classify_type(++a) ? 1 : 0) + ++a; // ok
|
|
(__builtin_constant_p(++a) ? 1 : 0) + ++a; // ok
|
|
(__builtin_object_size(&(++a, a), 0) ? 1 : 0) + ++a; // ok
|
|
(__builtin_expect(++a, 0) ? 1 : 0) + ++a; // expected-warning {{multiple unsequenced modifications}}
|
|
}
|