llvm-project/clang/test/Analysis/uninit-vals-ps-region.m

// RUN: %clang_analyze_cc1 -analyzer-store=region -analyzer-checker=core -verify %s

struct s {
  int data;
};

struct s global;

void g(int);

void f4() {
  int a;
  if (global.data == 0)
    a = 3;
  if (global.data == 0) // When the true branch is feasible 'a = 3'.
    g(a); // no-warning
}


// Test uninitialized value due to part of the structure being uninitialized.
struct TestUninit { int x; int y; };
struct TestUninit test_uninit_aux();
void test_unit_aux2(int);
void test_uninit_pos() {
  struct TestUninit v1 = { 0, 0 };
  struct TestUninit v2 = test_uninit_aux();
  int z;
  v1.y = z; // expected-warning{{Assigned value is garbage or undefined}}
  test_unit_aux2(v2.x + v1.y);
}
void test_uninit_pos_2() {
  struct TestUninit v1 = { 0, 0 };
  struct TestUninit v2;
  test_unit_aux2(v2.x + v1.y);  // expected-warning{{The left operand of '+' is a garbage value}}
}
void test_uninit_pos_3() {
  struct TestUninit v1 = { 0, 0 };
  struct TestUninit v2;
  test_unit_aux2(v1.y + v2.x);  // expected-warning{{The right operand of '+' is a garbage value}}
}

void test_uninit_neg() {
  struct TestUninit v1 = { 0, 0 };
  struct TestUninit v2 = test_uninit_aux();
  test_unit_aux2(v2.x + v1.y);
}

extern void test_uninit_struct_arg_aux(struct TestUninit arg);
void test_uninit_struct_arg() {
  struct TestUninit x;
  test_uninit_struct_arg_aux(x); // expected-warning{{Passed-by-value struct argument contains uninitialized data (e.g., field: 'x')}}
}

@interface Foo
- (void) passVal:(struct TestUninit)arg;
@end
void testFoo(Foo *o) {
  struct TestUninit x;
  [o passVal:x]; // expected-warning{{Passed-by-value struct argument contains uninitialized data (e.g., field: 'x')}}
}

// Test case from <rdar://problem/7780304>.  That shows an uninitialized value
// being used in the LHS of a compound assignment.
void rdar_7780304() {
  typedef struct s_r7780304 { int x; } s_r7780304;
  s_r7780304 b;
  b.x |= 1; // expected-warning{{The left expression of the compound assignment is an uninitialized value. The computed value will also be garbage}}
}


// The flip side of PR10163 -- float arrays that are actually uninitialized
// (The main test is in uninit-vals.m)
void test_PR10163(float);
void PR10163 (void) {
  float x[2];
  test_PR10163(x[1]); // expected-warning{{uninitialized value}}
}

struct MyStr {
  int x;
  int y;
};
void swap(struct MyStr *To, struct MyStr *From) {
  // This is not really a swap but close enough for our test.
  To->x = From->x;
  To->y = From->y; // no warning
}
int test_undefined_member_assignment_in_swap(struct MyStr *s2) {
  struct MyStr s1;
  s1.x = 5;
  swap(s2, &s1);
  return s2->y; // expected-warning{{Undefined or garbage value returned to caller}}
}