forked from OSchip/llvm-project
				
			
		
			
				
	
	
		
			124 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			124 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
| // 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 {{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 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{{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}}
 | |
| }
 | |
| 
 | |
| // 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_fabsf(0); // expected-warning {{ignoring return value of function declared with const 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));
 |