unused-expr.c revision 5bef8ddabfe157aa6f1f9010d3d144215b3e731a
1// RUN: clang -fsyntax-only -verify -fno-math-errno %s 2 3int foo(int X, int Y); 4 5double sqrt(double X); // implicitly const because of -fno-math-errno! 6 7void bar(volatile int *VP, int *P, int A, 8 _Complex double C, volatile _Complex double VC) { 9 10 VP == P; // expected-warning {{expression result unused}} 11 (void)A; 12 (void)foo(1,2); // no warning. 13 14 A == foo(1, 2); // expected-warning {{expression result unused}} 15 16 foo(1,2)+foo(4,3); // expected-warning {{expression result unused}} 17 18 19 *P; // expected-warning {{expression result unused}} 20 *VP; // no warning. 21 P[4]; // expected-warning {{expression result unused}} 22 VP[4]; // no warning. 23 24 __real__ C; // expected-warning {{expression result unused}} 25 __real__ VC; 26 27 // We know this can't change errno because of -fno-math-errno. 28 sqrt(A); // expected-warning {{expression result unused}} 29} 30 31extern void t1(); 32extern void t2(); 33void t3(int c) { 34 c ? t1() : t2(); 35} 36 37// This shouldn't warn: the expr at the end of the stmtexpr really is used. 38int stmt_expr(int x, int y) { 39 return ({int _a = x, _b = y; _a > _b ? _a : _b; }); 40} 41 42void nowarn(unsigned char* a, unsigned char* b) 43{ 44 unsigned char c = 1; 45 *a |= c, *b += c; 46} 47