llvm-project/clang/test/Sema/unused-expr.c

77 lines
1.9 KiB
C

// RUN: clang-cc -fsyntax-only -verify -fmath-errno=0 %s
int foo(int X, int Y);
double sqrt(double X); // implicitly const because of -fno-math-errno!
void bar(volatile int *VP, int *P, int A,
_Complex double C, volatile _Complex double VC) {
VP == P; // expected-warning {{expression result unused}}
(void)A;
(void)foo(1,2); // no warning.
A == foo(1, 2); // expected-warning {{expression result unused}}
foo(1,2)+foo(4,3); // expected-warning {{expression result unused}}
*P; // expected-warning {{expression result unused}}
*VP; // no warning.
P[4]; // expected-warning {{expression result unused}}
VP[4]; // no warning.
__real__ C; // expected-warning {{expression result unused}}
__real__ VC;
// We know this can't change errno because of -fno-math-errno.
sqrt(A); // expected-warning {{expression result unused}}
}
extern void t1();
extern void t2();
void t3(int c) {
c ? t1() : t2();
}
// This shouldn't warn: the expr at the end of the stmtexpr really is used.
int stmt_expr(int x, int y) {
return ({int _a = x, _b = y; _a > _b ? _a : _b; });
}
void nowarn(unsigned char* a, unsigned char* b)
{
unsigned char c = 1;
*a |= c, *b += c;
// PR4633
int y, x;
((void)0), y = x;
}
void t4(int a) {
int b = 0;
if (a)
b == 1; // expected-warning{{expression result unused}}
else
b == 2; // expected-warning{{expression result unused}}
while (1)
b == 3; // expected-warning{{expression result unused}}
do
b == 4; // expected-warning{{expression result unused}}
while (1);
for (;;)
b == 5; // expected-warning{{expression result unused}}
for (b == 1;;) {} // expected-warning{{expression result unused}}
for (;b == 1;) {}
for (;;b == 1) {} // expected-warning{{expression result unused}}
}