clang/test/SemaCXX/warn-unsafe-buffer-usage-libc-functions-inline-namespace.cpp

   1 // RUN: %clang_cc1 -std=c++20 -Wno-all -Wunsafe-buffer-usage \
   2 // RUN:            -verify %s
   3
   4 namespace std {
   5   inline namespace __1 {
   6   template< class InputIt, class OutputIt >
   7   OutputIt copy( InputIt first, InputIt last,
   8                  OutputIt d_first );
   9
  10   struct iterator{};
  11   template<typename T>
  12   struct span {
  13     T * ptr;
  14     T * data();
  15     unsigned size_bytes();
  16     unsigned size();
  17     iterator begin() const noexcept;
  18     iterator end() const noexcept;
  19   };
  20
  21   template<typename T>
  22   struct basic_string {
  23     T* p;
  24     T *c_str();
  25     T *data();
  26     unsigned size_bytes();
  27   };
  28
  29   typedef basic_string<char> string;
  30   typedef basic_string<wchar_t> wstring;
  31
  32   // C function under std:
  33   void memcpy();
  34   void strcpy();
  35   int snprintf( char* buffer, unsigned buf_size, const char* format, ... );
  36   }
  37 }
  38
  39 void f(char * p, char * q, std::span<char> s) {
  40   std::memcpy();              // expected-warning{{function 'memcpy' is unsafe}}
  41   std::strcpy();              // expected-warning{{function 'strcpy' is unsafe}}
  42   std::__1::memcpy();              // expected-warning{{function 'memcpy' is unsafe}}
  43   std::__1::strcpy();              // expected-warning{{function 'strcpy' is unsafe}}
  44
  45   /* Test printfs */
  46   std::snprintf(s.data(), 10, "%s%d", "hello", *p); // expected-warning{{function 'snprintf' is unsafe}} expected-note{{buffer pointer and size may not match}}
  47   std::__1::snprintf(s.data(), 10, "%s%d", "hello", *p); // expected-warning{{function 'snprintf' is unsafe}} expected-note{{buffer pointer and size may not match}}
  48   std::snprintf(s.data(), s.size_bytes(), "%s%d", "hello", *p); // no warn
  49   std::__1::snprintf(s.data(), s.size_bytes(), "%s%d", "hello", *p); // no warn
  50 }
  51
  52 void v(std::string s1) {
  53   std::snprintf(s1.data(), s1.size_bytes(), "%s%d", s1.c_str(), 0); // no warn
  54   std::__1::snprintf(s1.data(), s1.size_bytes(), "%s%d", s1.c_str(), 0); // no warn
  55 }
  56
  57 void g(char *begin, char *end, char *p, std::span<char> s) {
  58   std::copy(begin, end, p); // no warn
  59   std::copy(s.begin(), s.end(), s.begin()); // no warn
  60 }