warn-tautological-compare.c
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// RUN: %clang_cc1 -triple x86_64-apple-darwin -fsyntax-only -verify %s
// rdar://18716393
extern int a[] __attribute__((weak));
int b[] = {8,13,21};
struct {
int x[10];
} c;
const char str[] = "text";
void ignore() {
if (!a) {}
}
void test() {
if (!b) {} // expected-warning {{address of array 'b' will always evaluate to 'true'}}
if (b == 0) {} // expected-warning {{comparison of array 'b' equal to a null pointer is always false}}
if (!c.x) {} // expected-warning {{address of array 'c.x' will always evaluate to 'true'}}
if (c.x == 0) {} // expected-warning {{comparison of array 'c.x' equal to a null pointer is always false}}
if (!str) {} // expected-warning {{address of array 'str' will always evaluate to 'true'}}
if (0 == str) {} // expected-warning {{comparison of array 'str' equal to a null pointer is always false}}
}
int array[2];
int test1()
{
if (!array) { // expected-warning {{address of array 'array' will always evaluate to 'true'}}
return array[0];
} else if (array != 0) { // expected-warning {{comparison of array 'array' not equal to a null pointer is always true}}
return array[1];
}
if (array == 0) // expected-warning {{comparison of array 'array' equal to a null pointer is always false}}
return 1;
return 0;
}
#define NULL (void*)0
int test2(int* pointer, char ch, void * pv) {
if (!&pointer) { // expected-warning {{address of 'pointer' will always evaluate to 'true'}}
return 0;
}
if (&pointer) { // expected-warning {{address of 'pointer' will always evaluate to 'true'}}
return 0;
}
if (&pointer == NULL) {} // expected-warning {{comparison of address of 'pointer' equal to a null pointer is always false}}
if (&pointer != NULL) {} // expected-warning {{comparison of address of 'pointer' not equal to a null pointer is always true}}
return 1;
}
void test3() {
if (array) { } // expected-warning {{address of array 'array' will always evaluate to 'true'}}
if (array != 0) {} // expected-warning {{comparison of array 'array' not equal to a null pointer is always true}}
if (!array) { } // expected-warning {{address of array 'array' will always evaluate to 'true'}}
if (array == 0) {} // expected-warning {{comparison of array 'array' equal to a null pointer is always false}}
if (array[0] &&
array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
if (array[0] ||
array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
if (array[0] &&
!array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
if (array[0] ||
!array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
if (array && // expected-warning {{address of array 'array' will always evaluate to 'true'}}
array[0]) {}
if (!array || // expected-warning {{address of array 'array' will always evaluate to 'true'}}
array[0]) {}
if (array || // expected-warning {{address of array 'array' will always evaluate to 'true'}}
(!array && array[0])) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
}
// rdar://19256338
#define SAVE_READ(PTR) if( (PTR) && (&result) ) *result=*PTR;
void _HTTPClientErrorHandler(int me)
{
int *result;
SAVE_READ(&me);
}
void test_conditional_operator() {
int x;
x = b ? 1 : 0; // expected-warning {{address of array}}
x = c.x ? 1 : 0; // expected-warning {{address of array}}
x = str ? 1 : 0; // expected-warning {{address of array}}
x = array ? 1 : 0; // expected-warning {{address of array}}
x = &x ? 1 : 0; // expected-warning {{address of 'x'}}
}