158 lines
4.7 KiB
C
158 lines
4.7 KiB
C
// RUN: %clang_cc1 -fsyntax-only -verify %s -Wno-unreachable-code
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int foo(int X, int Y);
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double sqrt(double X); // implicitly const because of no -fmath-errno!
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void bar(volatile int *VP, int *P, int A,
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_Complex double C, volatile _Complex double VC) {
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VP < P; // expected-warning {{expression result unused}}
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(void)A;
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(void)foo(1,2); // no warning.
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A < foo(1, 2); // expected-warning {{expression result unused}}
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foo(1,2)+foo(4,3); // expected-warning {{expression result unused}}
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*P; // expected-warning {{expression result unused}}
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*VP; // no warning.
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P[4]; // expected-warning {{expression result unused}}
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VP[4]; // no warning.
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__real__ C; // expected-warning {{expression result unused}}
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__real__ VC;
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// We know this can't change errno because of no -fmath-errno.
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sqrt(A); // expected-warning {{ignoring return value of function declared with const attribute}}
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}
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extern void t1();
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extern void t2();
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void t3(int c) {
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c ? t1() : t2();
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}
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// This shouldn't warn: the expr at the end of the stmtexpr really is used.
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int stmt_expr(int x, int y) {
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return ({int _a = x, _b = y; _a > _b ? _a : _b; });
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}
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void nowarn(unsigned char* a, unsigned char* b)
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{
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unsigned char c = 1;
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*a |= c, *b += c;
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// PR4633
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int y, x;
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((void)0), y = x;
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}
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void t4(int a) {
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int b = 0;
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if (a)
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b < 1; // expected-warning{{expression result unused}}
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else
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b < 2; // expected-warning{{expression result unused}}
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while (1)
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b < 3; // expected-warning{{expression result unused}}
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do
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b < 4; // expected-warning{{expression result unused}}
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while (1);
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for (;;)
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b < 5; // expected-warning{{expression result unused}}
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for (b < 1;;) {} // expected-warning{{expression result unused}}
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for (;b < 1;) {}
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for (;;b < 1) {} // expected-warning{{expression result unused}}
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}
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// rdar://7186119
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int t5f(void) __attribute__((warn_unused_result));
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void t5() {
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t5f(); // expected-warning {{ignoring return value of function declared with warn_unused_result}}
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}
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int fn1() __attribute__ ((warn_unused_result));
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int fn2() __attribute__ ((pure));
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int fn3() __attribute__ ((__const));
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// rdar://6587766
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int t6() {
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if (fn1() < 0 || fn2(2,1) < 0 || fn3(2) < 0) // no warnings
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return -1;
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fn1(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}}
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fn2(92, 21); // expected-warning {{ignoring return value of function declared with pure attribute}}
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fn3(42); // expected-warning {{ignoring return value of function declared with const attribute}}
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__builtin_fabsf(0); // expected-warning {{ignoring return value of function declared with const attribute}}
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(void)0, fn1(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}}
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return 0;
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}
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int t7 __attribute__ ((warn_unused_result)); // expected-warning {{'warn_unused_result' attribute only applies to functions}}
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// PR4010
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int (*fn4)(void) __attribute__ ((warn_unused_result));
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void t8() {
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fn4(); // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}}
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}
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void t9() __attribute__((warn_unused_result)); // expected-warning {{attribute 'warn_unused_result' cannot be applied to functions without return value}}
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// rdar://7410924
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void *some_function(void);
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void t10() {
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(void*) some_function(); //expected-warning {{expression result unused; should this cast be to 'void'?}}
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}
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void f(int i, ...) {
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__builtin_va_list ap;
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__builtin_va_start(ap, i);
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__builtin_va_arg(ap, int);
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__builtin_va_end(ap);
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}
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// PR8371
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int fn5() __attribute__ ((__const));
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// Don't warn for unused expressions in macro bodies; however, do warn for
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// unused expressions in macro arguments. Macros below are reduced from code
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// found in the wild.
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#define NOP(a) (a)
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#define M1(a, b) (long)foo((a), (b))
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#define M2 (long)0;
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#define M3(a) (t3(a), fn2())
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#define M4(a, b) (foo((a), (b)) ? 0 : t3(a), 1)
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#define M5(a, b) (foo((a), (b)), 1)
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#define M6() fn1()
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#define M7() fn2()
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void t11(int i, int j) {
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M1(i, j); // no warning
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NOP((long)foo(i, j)); // expected-warning {{expression result unused}}
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M2; // no warning
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NOP((long)0); // expected-warning {{expression result unused}}
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M3(i); // no warning
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NOP((t3(i), fn2())); // expected-warning {{ignoring return value}}
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M4(i, j); // no warning
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NOP((foo(i, j) ? 0 : t3(i), 1)); // expected-warning {{expression result unused}}
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M5(i, j); // no warning
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NOP((foo(i, j), 1)); // expected-warning {{expression result unused}}
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M6(); // expected-warning {{ignoring return value}}
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M7(); // no warning
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}
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#undef NOP
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#undef M1
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#undef M2
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#undef M3
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#undef M4
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#undef M5
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#undef M6
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#undef M7
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