clang/test/Analysis/string.cpp

   1 // RUN: %clang_analyze_cc1 -analyzer-checker=core,unix,alpha.unix.cstring,debug.ExprInspection -verify %s
   2
   3 // Test functions that are called "memcpy" but aren't the memcpy
   4 // we're looking for. Unfortunately, this test cannot be put into
   5 // a namespace. The out-of-class weird memcpy needs to be recognized
   6 // as a normal C function for the test to make sense.
   7 typedef __typeof(sizeof(int)) size_t;
   8 void *memcpy(void *, const void *, size_t);
   9 size_t strlen(const char *s);
  10
  11 int sprintf(char *str, const char *format, ...);
  12 int snprintf(char *str, size_t size, const char *format, ...);
  13
  14 void clang_analyzer_warnIfReached();
  15
  16 struct S {
  17   static S s1, s2;
  18
  19   // A weird overload within the class that accepts a structure reference
  20   // instead of a pointer.
  21   void memcpy(void *, const S &, size_t);
  22   void test_in_class_weird_memcpy() {
  23     memcpy(this, s2, 1); // no-crash
  24   }
  25 };
  26
  27 // A similarly weird overload outside of the class.
  28 void *memcpy(void *, const S &, size_t);
  29
  30 void test_out_of_class_weird_memcpy() {
  31   memcpy(&S::s1, S::s2, 1); // no-crash
  32 }
  33
  34 template<typename... Args>
  35 void log(const char* fmt, const Args&... args) {
  36   char buf[100] = {};
  37   auto f = snprintf;
  38   auto g = sprintf;
  39   int n = 0;
  40   n += f(buf, 99, fmt, args...); // no-crash: The CalleeDecl is a VarDecl, but it's okay.
  41   n += g(buf, fmt, args...); // no-crash: Same.
  42   (void)n;
  43   clang_analyzer_warnIfReached(); // expected-warning {{REACHABLE}}
  44 }
  45
  46 void test_gh_74269_no_crash() {
  47   log("%d", 1);
  48 }
  49
  50 struct TestNotNullTerm {
  51   void test1() {
  52     TestNotNullTerm * const &x = this;
  53     strlen((char *)&x); // expected-warning{{Argument to string length function is not a null-terminated string}}
  54   }
  55 };
  56
  57 void test_notcstring_tempobject() {
  58   // FIXME: This warning from cstring.NotNullTerminated is a false positive.
  59   // Handling of similar cases is not perfect in other cstring checkers.
  60   // The fix would be a larger change in CStringChecker and affect multiple checkers.
  61   strlen((char[]){'a', 0}); // expected-warning{{Argument to string length function is a C++ temp object of type char[2], which is not a null-terminated string}}
  62 }