warn-assignment-condition.cpp
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// RUN: %clang_cc1 -fsyntax-only -Wparentheses -verify %s
struct A {
int foo();
friend A operator+(const A&, const A&);
A operator|=(const A&);
operator bool();
};
void test() {
int x, *p;
A a, b;
// With scalars.
if (x = 7) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
if ((x = 7)) {}
do {
} while (x = 7); // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
do {
} while ((x = 7));
while (x = 7) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
while ((x = 7)) {}
for (; x = 7; ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
for (; (x = 7); ) {}
if (p = p) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
if ((p = p)) {}
do {
} while (p = p); // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
do {
} while ((p = p));
while (p = p) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
while ((p = p)) {}
for (; p = p; ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
for (; (p = p); ) {}
// Initializing variables (shouldn't warn).
if (int y = x) {}
while (int y = x) {}
if (A y = a) {}
while (A y = a) {}
// With temporaries.
if (x = (b+b).foo()) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
if ((x = (b+b).foo())) {}
do {
} while (x = (b+b).foo()); // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
do {
} while ((x = (b+b).foo()));
while (x = (b+b).foo()) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
while ((x = (b+b).foo())) {}
for (; x = (b+b).foo(); ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
for (; (x = (b+b).foo()); ) {}
// With a user-defined operator.
if (a = b + b) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
if ((a = b + b)) {}
do {
} while (a = b + b); // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
do {
} while ((a = b + b));
while (a = b + b) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
while ((a = b + b)) {}
for (; a = b + b; ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '==' to turn this assignment into an equality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
for (; (a = b + b); ) {}
// Compound assignments.
if (x |= 2) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '!=' to turn this compound assignment into an inequality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
if (a |= b) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
// expected-note{{use '!=' to turn this compound assignment into an inequality comparison}} \
// expected-note{{place parentheses around the assignment to silence this warning}}
if ((x == 5)) {} // expected-warning {{equality comparison with extraneous parentheses}} \
// expected-note {{use '=' to turn this equality comparison into an assignment}} \
// expected-note {{remove extraneous parentheses around the comparison to silence this warning}}
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wparentheses-equality"
if ((x == 5)) {} // no-warning
#pragma clang diagnostic pop
if ((5 == x)) {}
#define EQ(x,y) ((x) == (y))
if (EQ(x, 5)) {}
#undef EQ
}
void (*fn)();
void test2() {
if ((fn == test2)) {} // expected-warning {{equality comparison with extraneous parentheses}} \
// expected-note {{use '=' to turn this equality comparison into an assignment}} \
// expected-note {{remove extraneous parentheses around the comparison to silence this warning}}
if ((test2 == fn)) {}
}
namespace rdar9027658 {
template <typename T>
void f(T t) {
if ((t.g == 3)) { } // expected-warning {{equality comparison with extraneous parentheses}} \
// expected-note {{use '=' to turn this equality comparison into an assignment}} \
// expected-note {{remove extraneous parentheses around the comparison to silence this warning}}
}
struct S { int g; };
void test() {
f(S()); // expected-note {{in instantiation}}
}
}