// 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); }