llvm-project/clang/test/Sema/uninit-variables.c

394 lines
10 KiB
C

// RUN: %clang_cc1 -fsyntax-only -Wuninitialized -Wconditional-uninitialized -fsyntax-only -fblocks %s -verify
typedef __typeof(sizeof(int)) size_t;
void *malloc(size_t);
int test1() {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
return x; // expected-warning{{variable 'x' is uninitialized when used here}}
}
int test2() {
int x = 0;
return x; // no-warning
}
int test3() {
int x;
x = 0;
return x; // no-warning
}
int test4() {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
++x; // expected-warning{{variable 'x' is uninitialized when used here}}
return x;
}
int test5() {
int x, y; // expected-note{{initialize the variable 'y' to silence this warning}}
x = y; // expected-warning{{variable 'y' is uninitialized when used here}}
return x;
}
int test6() {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
x += 2; // expected-warning{{variable 'x' is uninitialized when used here}}
return x;
}
int test7(int y) {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
if (y)
x = 1;
return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
}
int test8(int y) {
int x;
if (y)
x = 1;
else
x = 0;
return x;
}
int test9(int n) {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
for (unsigned i = 0 ; i < n; ++i) {
if (i == n - 1)
break;
x = 1;
}
return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
}
int test10(unsigned n) {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
for (unsigned i = 0 ; i < n; ++i) {
x = 1;
}
return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
}
int test11(unsigned n) {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
for (unsigned i = 0 ; i <= n; ++i) {
x = 1;
}
return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
}
void test12(unsigned n) {
for (unsigned i ; n ; ++i) ; // expected-warning{{variable 'i' is uninitialized when used here}} expected-note{{initialize the variable 'i' to silence this warning}}
}
int test13() {
static int i;
return i; // no-warning
}
// Simply don't crash on this test case.
void test14() {
const char *p = 0;
for (;;) {}
}
int test15() {
int x = x; // no-warning: signals intended lack of initialization. \
// expected-note{{variable 'x' is declared here}}
return x; // expected-warning{{variable 'x' is uninitialized when used here}}
}
// Don't warn in the following example; shows dataflow confluence.
char *test16_aux();
void test16() {
char *p = test16_aux();
for (unsigned i = 0 ; i < 100 ; i++)
p[i] = 'a'; // no-warning
}
void test17() {
// Don't warn multiple times about the same uninitialized variable
// along the same path.
int *x; // expected-note{{initialize the variable 'x' to silence this warning}}
*x = 1; // expected-warning{{variable 'x' is uninitialized when used here}}
*x = 1; // no-warning
}
int test18(int x, int y) {
int z;
if (x && y && (z = 1)) {
return z; // no-warning
}
return 0;
}
int test19_aux1();
int test19_aux2();
int test19_aux3(int *x);
int test19() {
int z;
if (test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z))
return z; // no-warning
return 0;
}
int test20() {
int z; // expected-note{{initialize the variable 'z' to silence this warning}}
if ((test19_aux1() + test19_aux2() && test19_aux1()) || test19_aux3(&z))
return z; // expected-warning{{variable 'z' may be uninitialized when used here}}
return 0;
}
int test21(int x, int y) {
int z; // expected-note{{initialize the variable 'z' to silence this warning}}
if ((x && y) || test19_aux3(&z) || test19_aux2())
return z; // expected-warning{{variable 'z' may be uninitialized when used here}}
return 0;
}
int test22() {
int z;
while (test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z))
return z; // no-warning
return 0;
}
int test23() {
int z;
for ( ; test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z) ; )
return z; // no-warning
return 0;
}
// The basic uninitialized value analysis doesn't have enough path-sensitivity
// to catch initializations relying on control-dependencies spanning multiple
// conditionals. This possibly can be handled by making the CFG itself
// represent such control-dependencies, but it is a niche case.
int test24(int flag) {
unsigned val; // expected-note{{initialize the variable 'val' to silence this warning}}
if (flag)
val = 1;
if (!flag)
val = 1;
return val; // expected-warning{{variable 'val' may be uninitialized when used here}}
}
float test25() {
float x; // expected-note{{initialize the variable 'x' to silence this warning}}
return x; // expected-warning{{variable 'x' is uninitialized when used here}}
}
typedef int MyInt;
MyInt test26() {
MyInt x; // expected-note{{initialize the variable 'x' to silence this warning}}
return x; // expected-warning{{variable 'x' is uninitialized when used here}}
}
// Test handling of sizeof().
int test27() {
struct test_27 { int x; } *y;
return sizeof(y->x); // no-warning
}
int test28() {
int len; // expected-note{{initialize the variable 'len' to silence this warning}}
return sizeof(int[len]); // expected-warning{{variable 'len' is uninitialized when used here}}
}
void test29() {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
(void) ^{ (void) x; }; // expected-warning{{variable 'x' is uninitialized when captured by block}}
}
void test30() {
static int x; // no-warning
(void) ^{ (void) x; };
}
void test31() {
__block int x; // no-warning
(void) ^{ (void) x; };
}
int test32_x;
void test32() {
(void) ^{ (void) test32_x; }; // no-warning
}
void test_33() {
int x; // no-warning
(void) x;
}
int test_34() {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
(void) x;
return x; // expected-warning{{variable 'x' is uninitialized when used here}}
}
// Test that this case doesn't crash.
void test35(int x) {
__block int y = 0;
^{ y = (x == 0); }();
}
// Test handling of indirect goto.
void test36()
{
void **pc; // expected-note{{initialize the variable 'pc' to silence this warning}}
void *dummy[] = { &&L1, &&L2 };
L1:
goto *pc; // expected-warning{{variable 'pc' is uninitialized when used here}}
L2:
goto *pc;
}
// Test && nested in ||.
int test37_a();
int test37_b();
int test37()
{
int identifier;
if ((test37_a() && (identifier = 1)) ||
(test37_b() && (identifier = 2))) {
return identifier; // no-warning
}
return 0;
}
// Test merging of path-specific dataflow values (without asserting).
int test38(int r, int x, int y)
{
int z;
return ((r < 0) || ((r == 0) && (x < y)));
}
int test39(int x) {
int y; // expected-note{{initialize the variable 'y' to silence this warning}}
int z = x + y; // expected-warning {{variable 'y' is uninitialized when used here}}
return z;
}
int test40(int x) {
int y; // expected-note{{initialize the variable 'y' to silence this warning}}
return x ? 1 : y; // expected-warning {{variable 'y' is uninitialized when used here}}
}
int test41(int x) {
int y; // expected-note{{initialize the variable 'y' to silence this warning}}
if (x) y = 1; // no-warning
return y; // expected-warning {{variable 'y' may be uninitialized when used here}}
}
void test42() {
int a;
a = 30; // no-warning
}
void test43_aux(int x);
void test43(int i) {
int x; // expected-note{{initialize the variable 'x' to silence this warning}}
for (i = 0 ; i < 10; i++)
test43_aux(x++); // expected-warning {{variable 'x' is uninitialized when used here}}
}
void test44(int i) {
int x = i;
int y; // expected-note{{initialize the variable 'y' to silence this warning}}
for (i = 0; i < 10; i++ ) {
test43_aux(x++); // no-warning
x += y; // expected-warning {{variable 'y' is uninitialized when used here}}
}
}
int test45(int j) {
int x = 1, y = x + 1;
if (y) // no-warning
return x;
return y;
}
void test46()
{
int i; // expected-note{{initialize the variable 'i' to silence this warning}}
int j = i ? : 1; // expected-warning {{variable 'i' is uninitialized when used here}}
}
void *test47(int *i)
{
return i ? : 0; // no-warning
}
void *test49(int *i)
{
int a;
return &a ? : i; // no-warning
}
void test50()
{
char c[1 ? : 2]; // no-warning
}
int test51(void)
{
__block int a;
^(void) {
a = 42;
}();
return a; // no-warning
}
// FIXME: This is a false positive, but it tests logical operations in switch statements.
int test52(int a, int b) {
int x; // expected-note {{initialize the variable 'x' to silence this warning}}
switch (a || b) { // expected-warning {{switch condition has boolean value}}
case 0:
x = 1;
break;
case 1:
x = 2;
break;
}
return x; // expected-warning {{variable 'x' may be uninitialized when used here}}
}
void test53() {
int x; // expected-note {{initialize the variable 'x' to silence this warning}}
int y = (x); // expected-warning {{variable 'x' is uninitialized when used here}}
}
// This CFG caused the uninitialized values warning to inf-loop.
extern int PR10379_g();
void PR10379_f(int *len) {
int new_len; // expected-note{{initialize the variable 'new_len' to silence this warning}}
for (int i = 0; i < 42 && PR10379_g() == 0; i++) {
if (PR10379_g() == 1)
continue;
if (PR10379_g() == 2)
PR10379_f(&new_len);
else if (PR10379_g() == 3)
PR10379_f(&new_len);
*len += new_len; // expected-warning {{variable 'new_len' may be uninitialized when used here}}
}
}
// Test that sizeof(VLA) doesn't trigger a warning.
void test_vla_sizeof(int x) {
double (*memory)[2][x] = malloc(sizeof(*memory)); // no-warning
}
// Test absurd case of deadcode + use of blocks. This previously was a false positive
// due to an analysis bug.
int test_block_and_dead_code() {
__block int x;
^{ x = 1; }();
if (0)
return x;
return x; // no-warning
}