clang/test/CodeGenCXX/weak-external.cpp

   1 // RUN: %clang_cc1 -fcxx-exceptions -fexceptions -triple %itanium_abi_triple %s -S -emit-llvm -o - | FileCheck %s
   2 // PR4262
   3
   4 // CHECK-NOT: _ZNSs12_S_constructIPKcEEPcT_S3_RKSaIcESt20forward_iterator_tag
   5
   6 // The "basic_string" extern template instantiation declaration is supposed to
   7 // suppress the implicit instantiation of non-inline member functions. Make sure
   8 // that we suppress the implicit instantiation of non-inline member functions
   9 // defined out-of-line. That we aren't instantiating the basic_string
  10 // constructor when we shouldn't be. Such an instantiation forces the implicit
  11 // instantiation of _S_construct<const char*>. Since _S_construct is a member
  12 // template, it's instantiation is *not* suppressed (despite being in
  13 // basic_string<char>), so we would emit it as a weak definition.
  14
  15 #define _LIBCPP_EXCEPTION_ABI __attribute__ ((__visibility__("default")))
  16 #define _LIBCPP_INLINE_VISIBILITY __attribute__ ((__visibility__("hidden"), __always_inline__))
  17 #define _LIBCPP_VISIBLE __attribute__ ((__visibility__("default")))
  18 #if (__has_feature(cxx_noexcept))
  19 #  define _NOEXCEPT noexcept
  20 #  define _NOEXCEPT_(x) noexcept(x)
  21 #else
  22 #  define _NOEXCEPT throw()
  23 #  define _NOEXCEPT_(x)
  24 #endif
  25
  26 namespace std  // purposefully not using versioning namespace
  27 {
  28
  29 template<class charT> struct char_traits;
  30 template<class T>     class allocator;
  31 template <class _CharT,
  32           class _Traits = char_traits<_CharT>,
  33           class _Allocator = allocator<_CharT> >
  34     class _LIBCPP_VISIBLE basic_string;
  35 typedef basic_string<char, char_traits<char>, allocator<char> > string;
  36
  37 class _LIBCPP_EXCEPTION_ABI exception
  38 {
  39 public:
  40     _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
  41     virtual ~exception() _NOEXCEPT;
  42     virtual const char* what() const _NOEXCEPT;
  43 };
  44
  45 class _LIBCPP_EXCEPTION_ABI runtime_error
  46     : public exception
  47 {
  48 private:
  49     void* __imp_;
  50 public:
  51     explicit runtime_error(const string&);
  52     explicit runtime_error(const char*);
  53
  54     runtime_error(const runtime_error&) _NOEXCEPT;
  55     runtime_error& operator=(const runtime_error&) _NOEXCEPT;
  56
  57     virtual ~runtime_error() _NOEXCEPT;
  58
  59     virtual const char* what() const _NOEXCEPT;
  60 };
  61
  62 }
  63
  64 void dummysymbol() {
  65   throw(std::runtime_error("string"));
  66 }
  67
  68 namespace not_weak_on_first {
  69   int func();
  70   // CHECK: {{.*}} extern_weak {{.*}} @_ZN17not_weak_on_first4funcEv(
  71   int func() __attribute__ ((weak));
  72
  73   typedef int (*FuncT)();
  74
  75   extern const FuncT table[] = {
  76       func,
  77   };
  78 }
  79
  80 namespace constant_eval {
  81   [[gnu::weak]] extern int a;
  82   // CHECK-LABEL: define {{.*}} @__cxx_global_var_init
  83   // CHECK:     store i8 zext (i1 icmp ne (ptr @_ZN13constant_eval1aE, ptr null) to i8), ptr @_ZN13constant_eval6has_a1E,
  84   bool has_a1 = &a;
  85   // CHECK-LABEL: define {{.*}} @__cxx_global_var_init
  86   // CHECK:     store i8 zext (i1 icmp ne (ptr @_ZN13constant_eval1aE, ptr null) to i8), ptr @_ZN13constant_eval6has_a2E,
  87   bool has_a2 = &a != nullptr;
  88
  89   struct X {
  90     [[gnu::weak]] void f();
  91   };
  92   // CHECK-LABEL: define {{.*}} @__cxx_global_var_init
  93   // CHECK:     store i8 zext (i1 icmp ne (i{{32|64}} ptrtoint (ptr @_ZN13constant_eval1X1fEv to i{{32|64}}), i{{32|64}} 0) to i8), ptr @_ZN13constant_eval6has_f1E,
  94   bool has_f1 = &X::f;
  95   // CHECK-LABEL: define {{.*}} @__cxx_global_var_init
  96   // CHECK:     store i8 zext (i1 icmp ne (i{{32|64}} ptrtoint (ptr @_ZN13constant_eval1X1fEv to i{{32|64}}), i{{32|64}} 0) to i8), ptr @_ZN13constant_eval6has_f2E,
  97   bool has_f2 = &X::f != nullptr;
  98 }