llvm-project/clang/test/Analysis/misc-ps-region-store.m

// RUN: %clang_cc1 -triple i386-apple-darwin9 -analyze -analyzer-experimental-internal-checks -checker-cfref -analyzer-store=region -verify -fblocks -analyzer-opt-analyze-nested-blocks %s
// RUN: %clang_cc1 -triple x86_64-apple-darwin9 -analyze -analyzer-experimental-internal-checks -checker-cfref -analyzer-store=region -verify -fblocks   -analyzer-opt-analyze-nested-blocks %s

typedef struct objc_selector *SEL;
typedef signed char BOOL;
typedef int NSInteger;
typedef unsigned int NSUInteger;
typedef struct _NSZone NSZone;
@class NSInvocation, NSMethodSignature, NSCoder, NSString, NSEnumerator;
@protocol NSObject  - (BOOL)isEqual:(id)object; @end
@protocol NSCopying  - (id)copyWithZone:(NSZone *)zone; @end
@protocol NSMutableCopying  - (id)mutableCopyWithZone:(NSZone *)zone; @end
@protocol NSCoding  - (void)encodeWithCoder:(NSCoder *)aCoder; @end
@interface NSObject <NSObject> {} - (id)init; @end
extern id NSAllocateObject(Class aClass, NSUInteger extraBytes, NSZone *zone);
@interface NSString : NSObject <NSCopying, NSMutableCopying, NSCoding>
- (NSUInteger)length;
+ (id)stringWithUTF8String:(const char *)nullTerminatedCString;
@end extern NSString * const NSBundleDidLoadNotification;
@interface NSAssertionHandler : NSObject {}
+ (NSAssertionHandler *)currentHandler;
- (void)handleFailureInMethod:(SEL)selector object:(id)object file:(NSString *)fileName lineNumber:(NSInteger)line description:(NSString *)format,...;
@end
extern NSString * const NSConnectionReplyMode;


//---------------------------------------------------------------------------
// Test case 'checkaccess_union' differs for region store and basic store.
// The basic store doesn't reason about compound literals, so the code
// below won't fire an "uninitialized value" warning.
//---------------------------------------------------------------------------

// PR 2948 (testcase; crash on VisitLValue for union types)
// http://llvm.org/bugs/show_bug.cgi?id=2948
void checkaccess_union() {
  int ret = 0, status;
  // Since RegionStore doesn't handle unions yet,
  // this branch condition won't be triggered
  // as involving an uninitialized value.  
  if (((((__extension__ (((union {  // no-warning
    __typeof (status) __in; int __i;}
    )
    {
      .__in = (status)}
      ).__i))) & 0xff00) >> 8) == 1)
        ret = 1;
}

// Check our handling of fields being invalidated by function calls.
struct test2_struct { int x; int y; char* s; };
void test2_helper(struct test2_struct* p);

char test2() {
  struct test2_struct s;
  test2_help(&s);
  char *p = 0;
  
  if (s.x > 1) {
    if (s.s != 0) {
      p = "hello";
    }
  }
  
  if (s.x > 1) {
    if (s.s != 0) {
      return *p;
    }
  }

  return 'a';
}

// BasicStore handles this case incorrectly because it doesn't reason about
// the value pointed to by 'x' and thus creates different symbolic values
// at the declarations of 'a' and 'b' respectively.  RegionStore handles
// it correctly. See the companion test in 'misc-ps-basic-store.m'.
void test_trivial_symbolic_comparison_pointer_parameter(int *x) {
  int a = *x;
  int b = *x;
  if (a != b) {
    int *p = 0;
    *p = 0xDEADBEEF;     // no-warning
  }
}

// This is a modified test from 'misc-ps.m'.  Here we have the extra
// NULL dereferences which are pruned out by RegionStore's symbolic reasoning
// of fields.
typedef struct _BStruct { void *grue; } BStruct;
void testB_aux(void *ptr);

void testB(BStruct *b) {
  {
    int *__gruep__ = ((int *)&((b)->grue));
    int __gruev__ = *__gruep__;
    int __gruev2__ = *__gruep__;
    if (__gruev__ != __gruev2__) {
      int *p = 0;
      *p = 0xDEADBEEF; // no-warning
    }

    testB_aux(__gruep__);
  }
  {
    int *__gruep__ = ((int *)&((b)->grue));
    int __gruev__ = *__gruep__;
    int __gruev2__ = *__gruep__;
    if (__gruev__ != __gruev2__) {
      int *p = 0;
      *p = 0xDEADBEEF; // no-warning
    }

    if (~0 != __gruev__) {}
  }
}

void testB_2(BStruct *b) {
  {
    int **__gruep__ = ((int **)&((b)->grue));
    int *__gruev__ = *__gruep__;
    testB_aux(__gruep__);
  }
  {
    int **__gruep__ = ((int **)&((b)->grue));
    int *__gruev__ = *__gruep__;
    if ((int*)~0 != __gruev__) {}
  }
}

// This test case is a reduced case of a caching bug discovered by an
// assertion failure in RegionStoreManager::BindArray.  Essentially the
// DeclStmt is evaluated twice, but on the second loop iteration the
// engine caches out.  Previously a false transition would cause UnknownVal
// to bind to the variable, firing an assertion failure.  This bug was fixed
// in r76262.
void test_declstmt_caching() {
again:
  {
    const char a[] = "I like to crash";
    goto again;
  }
}

//===----------------------------------------------------------------------===//
// Reduced test case from <rdar://problem/7114618>.
// Basically a null check is performed on the field value, which is then
// assigned to a variable and then checked again.
//===----------------------------------------------------------------------===//
struct s_7114618 { int *p; };
void test_rdar_7114618(struct s_7114618 *s) {
  if (s->p) {
    int *p = s->p;
    if (!p) {
      // Infeasible
      int *dead = 0;
      *dead = 0xDEADBEEF; // no-warning
    }
  }
}

// Test pointers increment correctly.
void f() {
  int a[2];
  a[1] = 3;
  int *p = a;
  p++;
  if (*p != 3) {
    int *q = 0;
    *q = 3; // no-warning
  }
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7185607>
// Bit-fields of a struct should be invalidated when blasting the entire
// struct with an integer constant.
//===----------------------------------------------------------------------===//
struct test_7185607 {
  int x : 10;
  int y : 22;
};
int rdar_test_7185607() {
  struct test_7185607 s; // Uninitialized.
  *((unsigned *) &s) = 0U;
  return s.x; // no-warning
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7242006> [RegionStore] compound literal assignment with
//  floats not honored
// This test case is mirrored in misc-ps.m, but this case is a negative.
//===----------------------------------------------------------------------===//
typedef float CGFloat;
typedef struct _NSSize {
    CGFloat width;
    CGFloat height;
} NSSize;

CGFloat rdar7242006_negative(CGFloat x) {
  NSSize y;
  return y.width; // expected-warning{{garbage}}
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7249340> - Allow binding of values to symbolic regions.
// This test case shows how RegionStore tracks the value bound to 'x'
// after the assignment.
//===----------------------------------------------------------------------===//
typedef int* ptr_rdar_7249340;
void rdar_7249340(ptr_rdar_7249340 x) {
  *x = 1;
  if (*x)
    return;
  int *p = 0;   // This is unreachable.
  *p = 0xDEADBEEF; // no-warning
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7249327> - This test case tests both value tracking of
// array values and that we handle symbolic values that are casted
// between different integer types.  Note the assignment 'n = *a++'; here
// 'n' is and 'int' and '*a' is 'unsigned'.  Previously we got a false positive
// at 'x += *b++' (undefined value) because we got a false path.
//===----------------------------------------------------------------------===//
int rdar_7249327_aux(void);

void rdar_7249327(unsigned int A[2*32]) {
  int B[2*32];
  int *b;
  unsigned int *a;
  int x = 0;
  
  int n;
  
  a = A;
  b = B;
  
  n = *a++;
  if (n)
    *b++ = rdar_7249327_aux();

  a = A;
  b = B;
  
  n = *a++;
  if (n)
    x += *b++; // no-warning
}

//===----------------------------------------------------------------------===//
// <rdar://problem/6914474> - Check that 'x' is invalidated because its
// address is passed in as a value to a struct.
//===----------------------------------------------------------------------===//
struct doodad_6914474 { int *v; };
extern void prod_6914474(struct doodad_6914474 *d);
int rdar_6914474(void) {
  int x;
  struct doodad_6914474 d;
  d.v = &x;
  prod_6914474(&d);
  return x; // no-warning
}

// Test invalidation of a single field.
struct s_test_field_invalidate {
  int x;
};
extern void test_invalidate_field(int *x);
int test_invalidate_field_test() {
  struct s_test_field_invalidate y;
  test_invalidate_field(&y.x);
  return y.x; // no-warning
}
int test_invalidate_field_test_positive() {
  struct s_test_field_invalidate y;
  return y.x; // expected-warning{{garbage}}
}

// This test case illustrates how a typeless array of bytes casted to a
// struct should be treated as initialized.  RemoveDeadBindings previously
// had a bug that caused 'x' to lose its default symbolic value after the
// assignment to 'p', thus causing 'p->z' to evaluate to "undefined".
struct ArrayWrapper { unsigned char y[16]; };
struct WrappedStruct { unsigned z; };

int test_handle_array_wrapper() {
  struct ArrayWrapper x;
  test_handle_array_wrapper(&x);
  struct WrappedStruct *p = (struct WrappedStruct*) x.y; // expected-warning{{Casting a non-structure type to a structure type and accessing a field can lead to memory access errors or data corruption.}}
  return p->z;  // no-warning
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7261075> [RegionStore] crash when 
//   handling load: '*((unsigned int *)"????")'
//===----------------------------------------------------------------------===//

int rdar_7261075(void) {
  unsigned int var = 0;
  if (var == *((unsigned int *)"????"))
    return 1;
  return 0;
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7275774> false path due to limited pointer 
//                          arithmetic constraints
//===----------------------------------------------------------------------===//

void rdar_7275774(void *data, unsigned n) {
  if (!(data || n == 0))
    return;
  
  unsigned short *p = (unsigned short*) data;
  unsigned short *q = p + (n / 2);

  if (p < q) {
    // If we reach here, 'p' cannot be null.  If 'p' is null, then 'n' must
    // be '0', meaning that this branch is not feasible.
    *p = *q; // no-warning
  }
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7312221>
//
//  Test that Objective-C instance variables aren't prematurely pruned
//  from the analysis state.
//===----------------------------------------------------------------------===//

struct rdar_7312221_value { int x; };

@interface RDar7312221
{
  struct rdar_7312221_value *y;
}
- (void) doSomething_7312221;
@end

extern struct rdar_7312221_value *rdar_7312221_helper();
extern int rdar_7312221_helper_2(id o);
extern void rdar_7312221_helper_3(int z);

@implementation RDar7312221
- (void) doSomething_7312221 {
  if (y == 0) {
    y = rdar_7312221_helper();
    if (y != 0) {
      y->x = rdar_7312221_helper_2(self);
      // The following use of 'y->x' previously triggered a null dereference, as the value of 'y'
      // before 'y = rdar_7312221_helper()' would be used.
      rdar_7312221_helper_3(y->x); // no-warning
    }
  }
}
@end

struct rdar_7312221_container {
  struct rdar_7312221_value *y;
};

extern int rdar_7312221_helper_4(struct rdar_7312221_container *s);

// This test case essentially matches the one in [RDar7312221 doSomething_7312221].
void doSomething_7312221_with_struct(struct rdar_7312221_container *Self) {
  if (Self->y == 0) {
    Self->y = rdar_7312221_helper();
    if (Self->y != 0) {
      Self->y->x = rdar_7312221_helper_4(Self);
      rdar_7312221_helper_3(Self->y->x); // no-warning
    }
  }
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7332673> - Just more tests cases for regions
//===----------------------------------------------------------------------===//

void rdar_7332673_test1() {
    char value[1];
    if ( *(value) != 1 ) {} // expected-warning{{The left operand of '!=' is a garbage value}}
}
void rdar_rdar_7332673_test2_aux(char *x);
void rdar_7332673_test2() {
    char *value;
    if ( rdar_7332673_test2_aux(value) != 1 ) {} // expected-warning{{Pass-by-value argument in function call is undefined}}
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7347252>: Because of a bug in
//   RegionStoreManager::RemoveDeadBindings(), the symbol for s->session->p
//   would incorrectly be pruned from the state after the call to
//   rdar7347252_malloc1(), and would incorrectly result in a warning about
//   passing a null pointer to rdar7347252_memcpy().
//===----------------------------------------------------------------------===//

struct rdar7347252_AA { char *p;};
typedef struct {
 struct rdar7347252_AA *session;
 int t;
 char *q;
} rdar7347252_SSL1;

int rdar7347252_f(rdar7347252_SSL1 *s);
char *rdar7347252_malloc1(int);
char *rdar7347252_memcpy1(char *d, char *s, int n) __attribute__((nonnull (1,2)));

int rdar7347252(rdar7347252_SSL1 *s) {
 rdar7347252_f(s);  // the SymbolicRegion of 's' is set a default binding of conjured symbol
 if (s->session->p == ((void*)0)) {
   if ((s->session->p = rdar7347252_malloc1(10)) == ((void*)0)) {
     return 0;
   }
   rdar7347252_memcpy1(s->session->p, "aa", 2); // no-warning
 }
 return 0;
}

//===----------------------------------------------------------------------===//
// PR 5316 - "crash when accessing field of lazy compound value"
//  Previously this caused a crash at the MemberExpr '.chr' when loading
//  a field value from a LazyCompoundVal
//===----------------------------------------------------------------------===//

typedef unsigned int pr5316_wint_t;
typedef pr5316_wint_t pr5316_REFRESH_CHAR;
typedef struct {
  pr5316_REFRESH_CHAR chr;
}
pr5316_REFRESH_ELEMENT;
static void pr5316(pr5316_REFRESH_ELEMENT *dst, const pr5316_REFRESH_ELEMENT *src) {
  while ((*dst++ = *src++).chr != L'\0')  ;
}

//===----------------------------------------------------------------------===//
// Exercise creating ElementRegion with symbolic super region.
//===----------------------------------------------------------------------===//
void element_region_with_symbolic_superregion(int* p) {
  int *x;
  int a;
  if (p[0] == 1)
    x = &a;
  if (p[0] == 1)
    (void)*x; // no-warning
}

//===----------------------------------------------------------------------===//
// Test returning an out-of-bounds pointer (CWE-466)
//===----------------------------------------------------------------------===//

static int test_cwe466_return_outofbounds_pointer_a[10];
int *test_cwe466_return_outofbounds_pointer() {
  int *p = test_cwe466_return_outofbounds_pointer_a+10;
  return p; // expected-warning{{Returned pointer value points outside the original object}}
}

//===----------------------------------------------------------------------===//
// PR 3135 - Test case that shows that a variable may get invalidated when its
// address is included in a structure that is passed-by-value to an unknown function.
//===----------------------------------------------------------------------===//

typedef struct { int *a; } pr3135_structure;
int pr3135_bar(pr3135_structure *x);
int pr3135() {
  int x;
  pr3135_structure y = { &x };
  // the call to pr3135_bar may initialize x
  if (pr3135_bar(&y) && x) // no-warning
    return 1;
  return 0;
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7403269> - Test that we handle compound initializers with
// partially unspecified array values. Previously this caused a crash.
//===----------------------------------------------------------------------===//

typedef struct RDar7403269 {
  unsigned x[10];
  unsigned y;
} RDar7403269;

void rdar7403269() {
  RDar7403269 z = { .y = 0 };
  if (z.x[4] == 0)
    return;
  int *p = 0;
  *p = 0xDEADBEEF; // no-warning  
}

typedef struct RDar7403269_b {
  struct zorg { int w; int k; } x[10];
  unsigned y;
} RDar7403269_b;

void rdar7403269_b() {
  RDar7403269_b z = { .y = 0 };
  if (z.x[5].w == 0)
    return;
  int *p = 0;
  *p = 0xDEADBEEF; // no-warning
}

void rdar7403269_b_pos() {
  RDar7403269_b z = { .y = 0 };
  if (z.x[5].w == 1)
    return;
  int *p = 0;
  *p = 0xDEADBEEF; // expected-warning{{Dereference of null pointer}}
}


//===----------------------------------------------------------------------===//
// Test that incrementing a non-null pointer results in a non-null pointer.
// (<rdar://problem/7191542>)
//===----------------------------------------------------------------------===//

void test_increment_nonnull_rdar_7191542(const char *path) {
  const char *alf = 0;
  
  for (;;) {
    // When using basic-store, we get a null dereference here because we lose information
    // about path after the pointer increment.
    char c = *path++; // no-warning
    if (c == 'a') {
      alf = path;
    }
    
    if (alf)
      return;
  }
}

//===----------------------------------------------------------------------===//
// Test that the store (implicitly) tracks values for doubles/floats that are
// uninitialized (<rdar://problem/6811085>)
//===----------------------------------------------------------------------===//

double rdar_6811085(void) {
  double u;
  return u + 10; // expected-warning{{The left operand of '+' is a garbage value}}
}

//===----------------------------------------------------------------------===//
// Path-sensitive tests for blocks.
//===----------------------------------------------------------------------===//

void indirect_block_call(void (^f)());

int blocks_1(int *p, int z) {
  __block int *q = 0;
  void (^bar)() = ^{ q = p; };
  
  if (z == 1) {
    // The call to 'bar' might cause 'q' to be invalidated.
    bar();
    *q = 0x1; // no-warning
  }
  else if (z == 2) {
    // The function 'indirect_block_call' might invoke bar, thus causing
    // 'q' to possibly be invalidated.
    indirect_block_call(bar);
    *q = 0x1; // no-warning
  }
  else {
    *q = 0xDEADBEEF; // expected-warning{{Dereference of null pointer}}
  }
  return z;
}

int blocks_2(int *p, int z) {
  int *q = 0;
  void (^bar)(int **) = ^(int **r){ *r = p; };
  
  if (z) {
    // The call to 'bar' might cause 'q' to be invalidated.
    bar(&q);
    *q = 0x1; // no-warning
  }
  else {
    *q = 0xDEADBEEF; // expected-warning{{Dereference of null pointer}}
  }
  return z;
}

//===----------------------------------------------------------------------===//
// <rdar://problem/7462324> - Test that variables passed using __blocks
//  are not treated as being uninitialized.
//===----------------------------------------------------------------------===//

typedef void (^RDar_7462324_Callback)(id obj);

@interface RDar7462324
- (void) foo:(id)target;
- (void) foo_positive:(id)target;

@end

@implementation RDar7462324
- (void) foo:(id)target {
  __block RDar_7462324_Callback builder = ((void*) 0);
  builder = ^(id object) {
    if (object) {
      builder(self); // no-warning
    }
  };
  builder(target);
}
- (void) foo_positive:(id)target {
  __block RDar_7462324_Callback builder = ((void*) 0);
  builder = ^(id object) {
    id x;
    if (object) {
      builder(x); // expected-warning{{Pass-by-value argument in function call is undefined}}
    }
  };
  builder(target);
}
@end

//===----------------------------------------------------------------------===//
// <rdar://problem/7468209> - Scanning for live variables within a block should
//  not crash on variables passed by reference via __block.
//===----------------------------------------------------------------------===//

int rdar7468209_aux();
void rdar7468209_aux2();

void rdar7468209() {
  __block int x = 0;
  ^{
    x = rdar7468209_aux();
    // We need a second statement so that 'x' would be removed from the store if it wasn't
    // passed by reference.
    rdar7468209_aux_2();
  }();
}