return.c
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// RUN: %clang_cc1 -triple x86_64-apple-darwin9 %s -fsyntax-only -Wignored-qualifiers -Wno-error=return-type -verify -fblocks -Wno-unreachable-code -Wno-unused-value
// clang emits the following warning by default.
// With GCC, -pedantic, -Wreturn-type or -Wall are required to produce the
// following warning.
int t14() {
return; // expected-warning {{non-void function 't14' should return a value}}
}
void t15() {
return 1; // expected-warning {{void function 't15' should not return a value}}
}
int unknown();
void test0() {
}
int test1() {
} // expected-warning {{non-void function does not return a value}}
int test2() {
a: goto a;
}
int test3() {
goto a;
a: ;
} // expected-warning {{non-void function does not return a value}}
void halt() {
a: goto a;
}
void halt2() __attribute__((noreturn));
int test4() {
halt2();
}
int test5() {
halt2(), (void)1;
}
int test6() {
1, halt2();
}
int j;
int unknown_nohalt() {
return j;
}
int test7() {
unknown();
} // expected-warning {{non-void function does not return a value}}
int test8() {
(void)(1 + unknown());
} // expected-warning {{non-void function does not return a value}}
int halt3() __attribute__((noreturn));
int test9() {
(void)(halt3() + unknown());
}
int test10() {
(void)(unknown() || halt3());
} // expected-warning {{non-void function does not return a value in all control paths}}
int test11() {
(void)(unknown() && halt3());
} // expected-warning {{non-void function does not return a value in all control paths}}
int test12() {
(void)(halt3() || unknown());
}
int test13() {
(void)(halt3() && unknown());
}
int test14() {
(void)(1 || unknown());
} // expected-warning {{non-void function does not return a value}}
int test15() {
(void)(0 || unknown());
} // expected-warning {{non-void function does not return a value}}
int test16() {
(void)(0 && unknown());
} // expected-warning {{non-void function does not return a value}}
int test17() {
(void)(1 && unknown());
} // expected-warning {{non-void function does not return a value}}
int test18() {
(void)(unknown_nohalt() && halt3());
} // expected-warning {{non-void function does not return a value in all control paths}}
int test19() {
(void)(unknown_nohalt() && unknown());
} // expected-warning {{non-void function does not return a value}}
int test20() {
int i;
if (i)
return 0;
else if (0)
return 2;
} // expected-warning {{non-void function does not return a value in all control paths}}
int test21() {
int i;
if (i)
return 0;
else if (1)
return 2;
}
int test22() {
int i;
switch (i) default: ;
} // expected-warning {{non-void function does not return a value}}
int test23() {
int i;
switch (i) {
case 0:
return 0;
case 2:
return 2;
}
} // expected-warning {{non-void function does not return a value in all control paths}}
int test24() {
int i;
switch (i) {
case 0:
return 0;
case 2:
return 2;
default:
return -1;
}
}
int test25() {
1 ? halt3() : unknown();
}
int test26() {
0 ? halt3() : unknown();
} // expected-warning {{non-void function does not return a value}}
int j;
void (*fptr)() __attribute__((noreturn));
int test27() {
switch (j) {
case 1:
do { } while (1);
break;
case 2:
for (;;) ;
break;
case 3:
for (;1;) ;
for (;0;) {
goto done;
}
return 1;
case 4:
while (0) { goto done; }
return 1;
case 5:
while (1) { return 1; }
break;
case 6:
fptr();
break;
default:
return 1;
}
done: ;
}
// PR4624
void test28() __attribute__((noreturn));
void test28(x) { while (1) { } }
void exit(int);
int test29() {
exit(1);
}
// Include these declarations here explicitly so we don't depend on system headers.
typedef struct __jmp_buf_tag{} jmp_buf[1];
extern void longjmp (struct __jmp_buf_tag __env[1], int __val) __attribute__ ((noreturn));
extern void _longjmp (struct __jmp_buf_tag __env[1], int __val) __attribute__ ((noreturn));
jmp_buf test30_j;
int test30() {
if (j)
longjmp(test30_j, 1);
else
#if defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__)
longjmp(test30_j, 2);
#else
_longjmp(test30_j, 1);
#endif
}
typedef void test31_t(int status);
void test31(test31_t *callback __attribute__((noreturn)));
void test32() {
^ (void) { while (1) { } }();
^ (void) { if (j) while (1) { } }();
while (1) { }
}
void test33() {
if (j) while (1) { }
}
// Test that 'static inline' functions are only analyzed for CFG-based warnings
// when they are used.
static inline int si_has_missing_return() {} // expected-warning{{non-void function does not return a value}}
static inline int si_has_missing_return_2() {}; // expected-warning{{non-void function does not return a value}}
static inline int si_forward();
static inline int si_has_missing_return_3(int x) {
if (x)
return si_has_missing_return_3(x+1);
} // expected-warning{{non-void function does not return a value in all control paths}}
int test_static_inline(int x) {
si_forward();
return x ? si_has_missing_return_2() : si_has_missing_return_3(x);
}
static inline int si_forward() {} // expected-warning{{non-void function does not return a value}}
// Test warnings on ignored qualifiers on return types.
const int ignored_c_quals(); // expected-warning{{'const' type qualifier on return type has no effect}}
const volatile int ignored_cv_quals(); // expected-warning{{'const volatile' type qualifiers on return type have no effect}}
char* const volatile restrict ignored_cvr_quals(); // expected-warning{{'const volatile restrict' type qualifiers on return type have no effect}}
typedef const int CI;
CI ignored_quals_typedef();
const CI ignored_quals_typedef_2(); // expected-warning{{'const' type qualifier}}
// Test that for switch(enum) that if the switch statement covers all the cases
// that we don't consider that for -Wreturn-type.
enum Cases { C1, C2, C3, C4 };
int test_enum_cases(enum Cases C) {
switch (C) {
case C1: return 1;
case C2: return 2;
case C4: return 3;
case C3: return 4;
}
} // no-warning
// PR12318 - Don't give a may reach end of non-void function warning.
int test34(int x) {
if (x == 1) {
return 3;
} else if ( x == 2 || 1) {
return 5;
}
}
// PR18999
int test35() {
lbl:
if (1)
goto lbl;
}
int test36a(int b) {
if (b)
return 43;
__builtin_unreachable();
}
int test36b(int b) {
if (b)
return 43;
__builtin_assume(0);
}
// PR19074.
void abort(void) __attribute__((noreturn));
#define av_assert0(cond) do {\
if (!(cond)) {\
abort();\
}\
} while (0)
int PR19074(int x) {
switch(x) {
case 0:
return 0;
default:
av_assert0(0);
} // no-warning
}
int PR19074_positive(int x) {
switch(x) {
case 0:
return 0;
default:
break;
}
} // expected-warning {{non-void function does not return a value in all control paths}}
// sizeof(long) test.
int sizeof_long() {
if (sizeof(long) == 4)
return 1;
if (sizeof(long) == 8)
return 2;
} // no-warning
int return_statement_expression() {
if (unknown())
return ({
while (0)
;
0;
});
else
return 0;
} // no-warning (used to be "non-void function does not return a value in all control paths")