clang/test/SemaCXX/functional-cast.cpp

   1 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
   2 // REQUIRES: LP64
   3
   4 // ------------ not interpreted as C-style cast ------------
   5
   6 struct SimpleValueInit {
   7   int i;
   8 };
   9
  10 struct InitViaConstructor {
  11   InitViaConstructor(int i = 7);
  12 };
  13
  14 struct NoValueInit { // expected-note 2 {{candidate constructor (the implicit copy constructor)}} expected-note 2 {{candidate constructor (the implicit move constructor)}}
  15   NoValueInit(int i, int j); // expected-note 2 {{candidate constructor}}
  16 };
  17
  18 void test_cxx_functional_value_init() {
  19   (void)SimpleValueInit();
  20   (void)InitViaConstructor();
  21   (void)NoValueInit(); // expected-error{{no matching constructor for initialization}}
  22 }
  23
  24 void test_cxx_function_cast_multi() {
  25   (void)NoValueInit(0, 0);
  26   (void)NoValueInit(0, 0, 0); // expected-error{{no matching constructor for initialization}}
  27   (void)int(1, 2); // expected-error{{excess elements in scalar initializer}}
  28   (void)int({}, 2);           // expected-error{{excess elements in scalar initializer}}
  29 }
  30
  31
  32 // ------------------ everything else --------------------
  33
  34 struct A {};
  35
  36 // ----------- const_cast --------------
  37
  38 typedef char c;
  39 typedef c *cp;
  40 typedef cp *cpp;
  41 typedef cpp *cppp;
  42 typedef cppp &cpppr;
  43 typedef const cppp &cpppcr;
  44 typedef const char cc;
  45 typedef cc *ccp;
  46 typedef volatile ccp ccvp;
  47 typedef ccvp *ccvpp;
  48 typedef const volatile ccvpp ccvpcvp;
  49 typedef ccvpcvp *ccvpcvpp;
  50 typedef int iar[100];
  51 typedef iar &iarr;
  52 typedef int (*f)(int);
  53
  54 void t_cc()
  55 {
  56   ccvpcvpp var = 0;
  57   // Cast away deep consts and volatiles.
  58   char ***var2 = cppp(var);
  59   char ***const &var3 = var2;
  60   // Const reference to reference.
  61   char ***&var4 = cpppr(var3);
  62   // Drop reference. Intentionally without qualifier change.
  63   char *** var5 = cppp(var4);
  64   const int ar[100] = {0};
  65   // Array decay. Intentionally without qualifier change.
  66   typedef int *intp;
  67   int *pi = intp(ar);
  68   f fp = 0;
  69   // Don't misidentify fn** as a function pointer.
  70   typedef f *fp_t;
  71   f *fpp = fp_t(&fp);
  72   int const A::* const A::*icapcap = 0;
  73   typedef int A::* A::*iapap_t;
  74   iapap_t iapap = iapap_t(icapcap);
  75 }
  76
  77 // ----------- static_cast -------------
  78
  79 struct B : public A {};             // Single public base.
  80 struct C1 : public virtual B {};    // Single virtual base.
  81 struct C2 : public virtual B {};
  82 struct D : public C1, public C2 {}; // Diamond
  83 struct E : private A {};            // Single private base.
  84 struct F : public C1 {};            // Single path to B with virtual.
  85 struct G1 : public B {};
  86 struct G2 : public B {};
  87 struct H : public G1, public G2 {}; // Ambiguous path to B.
  88
  89 enum Enum { En1, En2 };
  90 enum Onom { On1, On2 };
  91
  92 struct Co1 { operator int(); };
  93 struct Co2 { Co2(int); };
  94 struct Co3 { };
  95 struct Co4 { Co4(Co3); operator Co3(); };
  96
  97 // Explicit implicits
  98 void t_529_2()
  99 {
 100   int i = 1;
 101   (void)float(i);
 102   double d = 1.0;
 103   (void)float(d);
 104   (void)int(d);
 105   (void)char(i);
 106   typedef unsigned long ulong;
 107   (void)ulong(i);
 108   (void)int(En1);
 109   (void)double(En1);
 110   typedef int &intr;
 111   (void)intr(i);
 112   typedef const int &cintr;
 113   (void)cintr(i);
 114
 115   int ar[1];
 116   typedef const int *cintp;
 117   (void)cintp(ar);
 118   typedef void (*pfvv)();
 119   (void)pfvv(t_529_2);
 120
 121   typedef void *voidp;
 122   (void)voidp(0);
 123   (void)voidp((int*)0);
 124   typedef volatile const void *vcvoidp;
 125   (void)vcvoidp((const int*)0);
 126   typedef A *Ap;
 127   (void)Ap((B*)0);
 128   typedef A &Ar;
 129   (void)Ar(*((B*)0)); // expected-warning {{binding dereferenced null pointer to reference has undefined behavior}}
 130   typedef const B *cBp;
 131   (void)cBp((C1*)0);
 132   typedef B &Br;
 133   (void)Br(*((C1*)0)); // expected-warning {{binding dereferenced null pointer to reference has undefined behavior}}
 134   (void)Ap((D*)0);
 135   typedef const A &cAr;
 136   (void)cAr(*((D*)0)); // expected-warning {{binding dereferenced null pointer to reference has undefined behavior}}
 137   typedef int B::*Bmp;
 138   (void)Bmp((int A::*)0);
 139   typedef void (B::*Bmfp)();
 140   (void)Bmfp((void (A::*)())0);
 141   (void)Ap((E*)0); // functional-style cast ignores access control
 142   (void)voidp((const int*)0); // const_cast appended
 143
 144   (void)int(Co1());
 145   (void)Co2(1);
 146   (void)Co3((Co4)(Co3()));
 147
 148   // Bad code below
 149   //(void)(A*)((H*)0); // {{static_cast from 'struct H *' to 'struct A *' is not allowed}}
 150 }
 151
 152 // Anything to void
 153 void t_529_4()
 154 {
 155   void(1);
 156   (void(t_529_4));
 157 }
 158
 159 // Static downcasts
 160 void t_529_5_8()
 161 {
 162   typedef B *Bp;
 163   (void)Bp((A*)0);
 164   typedef B &Br;
 165   (void)Br(*((A*)0));
 166   typedef const G1 *cG1p;
 167   (void)cG1p((A*)0);
 168   typedef const G1 &cG1r;
 169   (void)cG1r(*((A*)0));
 170   (void)Bp((const A*)0); // const_cast appended
 171   (void)Br(*((const A*)0)); // const_cast appended
 172   typedef E *Ep;
 173   (void)Ep((A*)0); // access control ignored
 174   typedef E &Er;
 175   (void)Er(*((A*)0)); // access control ignored
 176
 177   // Bad code below
 178
 179   typedef C1 *C1p;
 180   (void)C1p((A*)0); // expected-error {{cannot cast 'A *' to 'C1p' (aka 'C1 *') via virtual base 'B'}}
 181   typedef C1 &C1r;
 182   (void)C1r(*((A*)0)); // expected-error {{cannot cast 'A' to 'C1r' (aka 'C1 &') via virtual base 'B'}}
 183   typedef D *Dp;
 184   (void)Dp((A*)0); // expected-error {{cannot cast 'A *' to 'Dp' (aka 'D *') via virtual base 'B'}}
 185   typedef D &Dr;
 186   (void)Dr(*((A*)0)); // expected-error {{cannot cast 'A' to 'Dr' (aka 'D &') via virtual base 'B'}}
 187   typedef H *Hp;
 188   (void)Hp((A*)0); // expected-error {{ambiguous cast from base 'A' to derived 'H':\n    A -> B -> G1 -> struct H\n    A -> B -> G2 -> struct H}}
 189   typedef H &Hr;
 190   (void)Hr(*((A*)0)); // expected-error {{ambiguous cast from base 'A' to derived 'H':\n    A -> B -> G1 -> struct H\n    A -> B -> G2 -> struct H}}
 191
 192   // TODO: Test DR427. This requires user-defined conversions, though.
 193 }
 194
 195 // Enum conversions
 196 void t_529_7()
 197 {
 198   (void)Enum(1);
 199   (void)Enum(1.0);
 200   (void)Onom(En1);
 201
 202   // Bad code below
 203
 204   (void)Enum((int*)0); // expected-error {{functional-style cast from 'int *' to 'Enum' is not allowed}}
 205 }
 206
 207 // Void pointer to object pointer
 208 void t_529_10()
 209 {
 210   typedef int *intp;
 211   (void)intp((void*)0);
 212   typedef const A *cAp;
 213   (void)cAp((void*)0);
 214   (void)intp((const void*)0); // const_cast appended
 215 }
 216
 217 // Member pointer upcast.
 218 void t_529_9()
 219 {
 220   typedef int A::*Amp;
 221   (void)Amp((int B::*)0);
 222
 223   // Bad code below
 224   (void)Amp((int H::*)0); // expected-error {{ambiguous conversion from pointer to member of derived class 'H' to pointer to member of base class 'A':}}
 225   (void)Amp((int F::*)0); // expected-error {{conversion from pointer to member of class 'F' to pointer to member of class 'A' via virtual base 'B' is not allowed}}
 226 }
 227
 228 // -------- reinterpret_cast -----------
 229
 230 enum test { testval = 1 };
 231 struct structure { int m; };
 232 typedef void (*fnptr)();
 233
 234 // Test conversion between pointer and integral types, as in p3 and p4.
 235 void integral_conversion()
 236 {
 237   typedef void *voidp;
 238   void *vp = voidp(testval);
 239   long l = long(vp);
 240   typedef float *floatp;
 241   (void)floatp(l);
 242   fnptr fnp = fnptr(l);
 243   (void)char(fnp); // expected-error {{cast from pointer to smaller type 'char' loses information}}
 244   (void)long(fnp);
 245 }
 246
 247 void pointer_conversion()
 248 {
 249   int *p1 = 0;
 250   typedef float *floatp;
 251   float *p2 = floatp(p1);
 252   typedef structure *structurep;
 253   structure *p3 = structurep(p2);
 254   typedef int **ppint;
 255   typedef ppint *pppint;
 256   ppint *deep = pppint(p3);
 257   typedef fnptr fnptrp;
 258   (void)fnptrp(deep);
 259 }
 260
 261 void constness()
 262 {
 263   int ***const ipppc = 0;
 264   typedef int const *icp_t;
 265   int const *icp = icp_t(ipppc);
 266   typedef int *intp;
 267   (void)intp(icp); // const_cast appended
 268   typedef int const *const ** intcpcpp;
 269   intcpcpp icpcpp = intcpcpp(ipppc); // const_cast appended
 270   int *ip = intp(icpcpp);
 271   (void)icp_t(ip);
 272   typedef int const *const *const *intcpcpcp;
 273   (void)intcpcpcp(ipppc);
 274 }
 275
 276 void fnptrs()
 277 {
 278   typedef int (*fnptr2)(int);
 279   fnptr fp = 0;
 280   (void)fnptr2(fp);
 281   typedef void *voidp;
 282   void *vp = voidp(fp);
 283   (void)fnptr(vp);
 284 }
 285
 286 void refs()
 287 {
 288   long l = 0;
 289   typedef char &charr;
 290   char &c = charr(l);
 291   // Bad: from rvalue
 292   typedef int &intr;
 293   (void)intr(&c); // expected-error {{functional-style cast from rvalue to reference type 'intr' (aka 'int &')}}
 294 }
 295
 296 void memptrs()
 297 {
 298   const int structure::*psi = 0;
 299   typedef const float structure::*structurecfmp;
 300   (void)structurecfmp(psi);
 301   typedef int structure::*structureimp;
 302   (void)structureimp(psi); // const_cast appended
 303
 304   void (structure::*psf)() = 0;
 305   typedef int (structure::*structureimfp)();
 306   (void)structureimfp(psf);
 307
 308   typedef void (structure::*structurevmfp)();
 309   (void)structurevmfp(psi); // expected-error-re {{functional-style cast from 'const int structure::*' to 'structurevmfp' (aka 'void (structure::*)(){{( __attribute__\(\(thiscall\)\))?}}') is not allowed}}
 310   (void)structureimp(psf); // expected-error-re {{functional-style cast from 'void (structure::*)(){{( __attribute__\(\(thiscall\)\))?}}' to 'structureimp' (aka 'int structure::*') is not allowed}}
 311 }
 312
 313 // ---------------- misc ------------------
 314
 315 void crash_on_invalid_1()
 316 {
 317   typedef itn Typo; // expected-error {{unknown type name 'itn'}}
 318   (void)Typo(1); // used to crash
 319
 320   typedef int &int_ref;
 321   (void)int_ref(); // expected-error {{reference to type 'int' requires an initializer}}
 322 }