llvm-project/clang/test/Analysis/casts.c

// RUN: %clang_analyze_cc1 -triple x86_64-apple-darwin9 -analyzer-checker=core,alpha.core,debug.ExprInspection -analyzer-store=region -verify %s
// RUN: %clang_analyze_cc1 -triple i386-apple-darwin9 -analyzer-checker=core,alpha.core,debug.ExprInspection -analyzer-store=region -verify %s

extern void clang_analyzer_eval(_Bool);

// Test if the 'storage' region gets properly initialized after it is cast to
// 'struct sockaddr *'. 

typedef unsigned char __uint8_t;
typedef unsigned int __uint32_t;
typedef __uint32_t __darwin_socklen_t;
typedef __uint8_t sa_family_t;
typedef __darwin_socklen_t socklen_t;
struct sockaddr { sa_family_t sa_family; };
struct sockaddr_storage {};

void getsockname();

void f(int sock) {
  struct sockaddr_storage storage;
  struct sockaddr* sockaddr = (struct sockaddr*)&storage; // expected-warning{{Casting data to a larger structure type and accessing a field can lead to memory access errors or data corruption}}
  socklen_t addrlen = sizeof(storage);
  getsockname(sock, sockaddr, &addrlen);
  switch (sockaddr->sa_family) { // no-warning
  default:
    ;
  }
}

struct s {
  struct s *value;
};

void f1(struct s **pval) {
  int *tbool = ((void*)0);
  struct s *t = *pval;
  pval = &(t->value);
  tbool = (int *)pval; // use the cast-to type 'int *' to create element region.
  char c = (unsigned char) *tbool; // Should use cast-to type to create symbol.
  if (*tbool == -1) // here load the element region with the correct type 'int'
    (void)3;
}

void f2(const char *str) {
 unsigned char ch, cl, *p;

 p = (unsigned char *)str;
 ch = *p++; // use cast-to type 'unsigned char' to create element region.
 cl = *p++;
 if(!cl)
    cl = 'a';
}

// Test cast VariableSizeArray to pointer does not crash.
void *memcpy(void *, void const *, unsigned long);
typedef unsigned char Byte;
void doit(char *data, int len) {
    if (len) {
        Byte buf[len];
        memcpy(buf, data, len);
    }
}

// PR 6013 and 6035 - Test that a cast of a pointer to long and then to int does not crash SValuator.
void pr6013_6035_test(void *p) {
  unsigned int foo;
  foo = ((long)(p));
  (void) foo;
}

// PR12511 and radar://11215362 - Test that we support SymCastExpr, which represents symbolic int to float cast.
char ttt(int intSeconds) {
  double seconds = intSeconds;
  if (seconds)
    return 0;
  return 0;
}

int foo (int* p) {
  int y = 0;
  if (p == 0) {
    if ((*((void**)&p)) == (void*)0) // Test that the cast to void preserves the symbolic region.
      return 0;
    else
      return 5/y; // This code should be unreachable: no-warning.
  }
  return 0;
}

void castsToBool() {
  clang_analyzer_eval(0); // expected-warning{{FALSE}}
  clang_analyzer_eval(0U); // expected-warning{{FALSE}}
  clang_analyzer_eval((void *)0); // expected-warning{{FALSE}}

  clang_analyzer_eval(1); // expected-warning{{TRUE}}
  clang_analyzer_eval(1U); // expected-warning{{TRUE}}
  clang_analyzer_eval(-1); // expected-warning{{TRUE}}
  clang_analyzer_eval(0x100); // expected-warning{{TRUE}}
  clang_analyzer_eval(0x100U); // expected-warning{{TRUE}}
  clang_analyzer_eval((void *)0x100); // expected-warning{{TRUE}}

  extern int symbolicInt;
  clang_analyzer_eval(symbolicInt); // expected-warning{{UNKNOWN}}
  if (symbolicInt)
    clang_analyzer_eval(symbolicInt); // expected-warning{{TRUE}}

  extern void *symbolicPointer;
  clang_analyzer_eval(symbolicPointer); // expected-warning{{UNKNOWN}}
  if (symbolicPointer)
    clang_analyzer_eval(symbolicPointer); // expected-warning{{TRUE}}

  int localInt;
  int* ptr = &localInt;
  clang_analyzer_eval(ptr); // expected-warning{{TRUE}}
  clang_analyzer_eval(&castsToBool); // expected-warning{{TRUE}}
  clang_analyzer_eval("abc"); // expected-warning{{TRUE}}

  extern float globalFloat;
  clang_analyzer_eval(globalFloat); // expected-warning{{UNKNOWN}}
}

void locAsIntegerCasts(void *p) {
  int x = (int) p;
  clang_analyzer_eval(++x < 10); // no-crash // expected-warning{{UNKNOWN}}
}

void multiDimensionalArrayPointerCasts() {
  static int x[10][10];
  int *y1 = &(x[3][5]);
  char *z = ((char *) y1) + 2;
  int *y2 = (int *)(z - 2);
  int *y3 = ((int *)x) + 35; // This is offset for [3][5].

  clang_analyzer_eval(y1 == y2); // expected-warning{{TRUE}}

  // FIXME: should be FALSE (i.e. equal pointers).
  clang_analyzer_eval(y1 - y2); // expected-warning{{UNKNOWN}}
  // FIXME: should be TRUE (i.e. same symbol).
  clang_analyzer_eval(*y1 == *y2); // expected-warning{{UNKNOWN}}

  clang_analyzer_eval(*((char *)y1) == *((char *) y2)); // expected-warning{{TRUE}}

  clang_analyzer_eval(y1 == y3); // expected-warning{{TRUE}}

  // FIXME: should be FALSE (i.e. equal pointers).
  clang_analyzer_eval(y1 - y3); // expected-warning{{UNKNOWN}}
  // FIXME: should be TRUE (i.e. same symbol).
  clang_analyzer_eval(*y1 == *y3); // expected-warning{{UNKNOWN}}

  clang_analyzer_eval(*((char *)y1) == *((char *) y3)); // expected-warning{{TRUE}}
}