| // RUN: %clang_cc1 -fsyntax-only -verify %s -Wno-unreachable-code |
| |
| int foo(int X, int Y); |
| |
| double sqrt(double X); // implicitly const because of no -fmath-errno! |
| |
| void bar(volatile int *VP, int *P, int A, |
| _Complex double C, volatile _Complex double VC) { |
| |
| VP < P; // expected-warning {{relational comparison result unused}} |
| (void)A; |
| (void)foo(1,2); // no warning. |
| |
| A < foo(1, 2); // expected-warning {{relational comparison 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 no -fmath-errno. |
| sqrt(A); // expected-warning {{ignoring return value of function declared with const attribute}} |
| } |
| |
| 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{{relational comparison result unused}} |
| else |
| b < 2; // expected-warning{{relational comparison result unused}} |
| |
| while (1) |
| b < 3; // expected-warning{{relational comparison result unused}} |
| |
| do |
| b < 4; // expected-warning{{relational comparison result unused}} |
| while (1); |
| |
| for (;;) |
| b < 5; // expected-warning{{relational comparison result unused}} |
| |
| for (b < 1;;) {} // expected-warning{{relational comparison result unused}} |
| for (;b < 1;) {} |
| for (;;b < 1) {} // expected-warning{{relational comparison result unused}} |
| } |
| |
| // rdar://7186119 |
| int t5f(void) __attribute__((warn_unused_result)); |
| void t5() { |
| t5f(); // expected-warning {{ignoring return value of function declared with warn_unused_result}} |
| } |
| |
| |
| int fn1() __attribute__ ((warn_unused_result)); |
| int fn2() __attribute__ ((pure)); |
| int fn3() __attribute__ ((__const)); |
| // rdar://6587766 |
| int t6() { |
| if (fn1() < 0 || fn2(2,1) < 0 || fn3(2) < 0) // no warnings |
| return -1; |
| |
| fn1(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}} |
| fn2(92, 21); // expected-warning {{ignoring return value of function declared with pure attribute}} |
| fn3(42); // expected-warning {{ignoring return value of function declared with const attribute}} |
| __builtin_abs(0); // expected-warning {{ignoring return value of function declared with const attribute}} |
| (void)0, fn1(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}} |
| return 0; |
| } |
| |
| int t7 __attribute__ ((warn_unused_result)); // expected-warning {{'warn_unused_result' attribute only applies to functions}} |
| |
| // PR4010 |
| int (*fn4)(void) __attribute__ ((warn_unused_result)); |
| void t8() { |
| fn4(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}} |
| } |
| |
| void t9() __attribute__((warn_unused_result)); // expected-warning {{attribute 'warn_unused_result' cannot be applied to functions without return value}} |
| |
| // rdar://7410924 |
| void *some_function(void); |
| void t10() { |
| (void*) some_function(); //expected-warning {{expression result unused; should this cast be to 'void'?}} |
| } |
| |
| void f(int i, ...) { |
| __builtin_va_list ap; |
| |
| __builtin_va_start(ap, i); |
| __builtin_va_arg(ap, int); |
| __builtin_va_end(ap); |
| } |
| |
| // PR8371 |
| int fn5() __attribute__ ((__const)); |
| |
| // Don't warn for unused expressions in macro bodies; however, do warn for |
| // unused expressions in macro arguments. Macros below are reduced from code |
| // found in the wild. |
| #define NOP(a) (a) |
| #define M1(a, b) (long)foo((a), (b)) |
| #define M2 (long)0; |
| #define M3(a) (t3(a), fn2()) |
| #define M4(a, b) (foo((a), (b)) ? 0 : t3(a), 1) |
| #define M5(a, b) (foo((a), (b)), 1) |
| #define M6() fn1() |
| #define M7() fn2() |
| void t11(int i, int j) { |
| M1(i, j); // no warning |
| NOP((long)foo(i, j)); // expected-warning {{expression result unused}} |
| M2; // no warning |
| NOP((long)0); // expected-warning {{expression result unused}} |
| M3(i); // no warning |
| NOP((t3(i), fn2())); // expected-warning {{ignoring return value}} |
| M4(i, j); // no warning |
| NOP((foo(i, j) ? 0 : t3(i), 1)); // expected-warning {{expression result unused}} |
| M5(i, j); // no warning |
| NOP((foo(i, j), 1)); // expected-warning {{expression result unused}} |
| M6(); // expected-warning {{ignoring return value}} |
| M7(); // no warning |
| } |
| #undef NOP |
| #undef M1 |
| #undef M2 |
| #undef M3 |
| #undef M4 |
| #undef M5 |
| #undef M6 |
| #undef M7 |
| |
| #define UNREFERENCED_PARAMETER(x) (x) |
| |
| void unused_parm(int a) { |
| // Don't warn if the warning is introduced by a macro that's spelled |
| // UNREFERENCED_PARAMETER, as that's a commonly used macro in Windows headers. |
| UNREFERENCED_PARAMETER(a); |
| } |