clang/test/SemaCXX/warn-cast-align.cpp

   1 // RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fsyntax-only -Wno-unused-value -Wcast-align -verify %s
   2
   3 // Simple casts.
   4 void test0(char *P) {
   5   char *a; short *b; int *c;
   6
   7   a = (char*) P;
   8   a = static_cast<char*>(P);
   9   a = reinterpret_cast<char*>(P);
  10   typedef char *CharPtr;
  11   a = CharPtr(P);
  12
  13   b = (short*) P; // expected-warning {{cast from 'char *' to 'short *' increases required alignment from 1 to 2}}
  14   b = reinterpret_cast<short*>(P);
  15   typedef short *ShortPtr;
  16   b = ShortPtr(P); // expected-warning {{cast from 'char *' to 'ShortPtr' (aka 'short *') increases required alignment from 1 to 2}}
  17
  18   c = (int*) P; // expected-warning {{cast from 'char *' to 'int *' increases required alignment from 1 to 4}}
  19   c = reinterpret_cast<int*>(P);
  20   typedef int *IntPtr;
  21   c = IntPtr(P); // expected-warning {{cast from 'char *' to 'IntPtr' (aka 'int *') increases required alignment from 1 to 4}}
  22 }
  23
  24 // Casts from void* are a special case.
  25 void test1(void *P) {
  26   char *a; short *b; int *c;
  27
  28   a = (char*) P;
  29   a = static_cast<char*>(P);
  30   a = reinterpret_cast<char*>(P);
  31   typedef char *CharPtr;
  32   a = CharPtr(P);
  33
  34   b = (short*) P;
  35   b = static_cast<short*>(P);
  36   b = reinterpret_cast<short*>(P);
  37   typedef short *ShortPtr;
  38   b = ShortPtr(P);
  39
  40   c = (int*) P;
  41   c = static_cast<int*>(P);
  42   c = reinterpret_cast<int*>(P);
  43   typedef int *IntPtr;
  44   c = IntPtr(P);
  45 }
  46
  47 struct __attribute__((aligned(16))) AlignedS {
  48   char m[16];
  49 };
  50
  51 struct __attribute__((aligned(16))) A {
  52   char m0[16];
  53   char m1[16];
  54   AlignedS *getAlignedS() {
  55     return (AlignedS *)m1;
  56   }
  57 };
  58
  59 struct B0 {
  60   char m0[16];
  61 };
  62
  63 struct B1 {
  64   char m0[16];
  65 };
  66
  67 struct C {
  68   A &m0;
  69   B0 &m1;
  70   A m2;
  71 };
  72
  73 struct __attribute__((aligned(16))) D0 : B0, B1 {
  74 };
  75
  76 struct __attribute__((aligned(16))) D1 : virtual B0 {
  77 };
  78
  79 struct B2 {
  80   char m0[8];
  81 };
  82
  83 struct B3 {
  84   char m0[8];
  85 };
  86
  87 struct B4 {
  88   char m0[8];
  89 };
  90
  91 struct D2 : B2, B3 {
  92 };
  93
  94 struct __attribute__((aligned(16))) D3 : B4, D2 {
  95 };
  96
  97 struct __attribute__((aligned(16))) D4 : virtual D2 {
  98 };
  99
 100 struct D5 : virtual D0 {
 101   char m0[16];
 102   AlignedS *get() {
 103     return (AlignedS *)m0; // expected-warning {{cast from 'char *' to 'AlignedS *'}}
 104   }
 105 };
 106
 107 struct D6 : virtual D5 {
 108 };
 109
 110 struct D7 : virtual D3 {
 111 };
 112
 113 void test2(int n, A *a2) {
 114   __attribute__((aligned(16))) char m[sizeof(A) * 2];
 115   char(&m_ref)[sizeof(A) * 2] = m;
 116   extern char(&m_ref_noinit)[sizeof(A) * 2];
 117   __attribute__((aligned(16))) char vararray[10][n];
 118   A t0;
 119   B0 t1;
 120   C t2 = {.m0 = t0, .m1 = t1};
 121   __attribute__((aligned(16))) char t3[5][5][5];
 122   __attribute__((aligned(16))) char t4[4][16];
 123   D0 t5;
 124   D1 t6;
 125   D3 t7;
 126   D4 t8;
 127   D6 t9;
 128   __attribute__((aligned(1))) D7 t10;
 129
 130   A *a;
 131   a = (A *)&m;
 132   a = (A *)(m + sizeof(A));
 133   a = (A *)(sizeof(A) + m);
 134   a = (A *)((sizeof(A) * 2 + m) - sizeof(A));
 135   a = (A *)((sizeof(A) * 2 + m) - 1); // expected-warning {{cast from 'char *' to 'A *'}}
 136   a = (A *)(m + 1);                   // expected-warning {{cast from 'char *' to 'A *'}}
 137   a = (A *)(1 + m);                   // expected-warning {{cast from 'char *' to 'A *'}}
 138   a = (A *)(m + n);                   // expected-warning {{cast from 'char *' to 'A *'}}
 139   a = (A *)&*&m[sizeof(A)];
 140   a = (A *)(0, 0, &m[sizeof(A)]);
 141   a = (A *)&(0, 0, *&m[sizeof(A)]);
 142   a = (A *)&m[n]; // expected-warning {{cast from 'char *' to 'A *'}}
 143   a = (A *)&m_ref;
 144   a = (A *)&m_ref_noinit;        // expected-warning {{cast from 'char (*)[64]' to 'A *'}}
 145   a = (A *)(&vararray[4][0]);    // expected-warning {{cast from 'char *' to 'A *'}}
 146   a = (A *)(a2->m0 + sizeof(A)); // expected-warning {{cast from 'char *' to 'A *'}}
 147   a = (A *)(&t2.m0);
 148   a = (A *)(&t2.m1); // expected-warning {{cast from 'B0 *' to 'A *'}}
 149   a = (A *)(&t2.m2);
 150   a = (A *)(t2.m2.m1);
 151   a = (A *)(&t3[3][3][0]); // expected-warning {{cast from 'char *' to 'A *'}}
 152   a = (A *)(&t3[2][2][4]);
 153   a = (A *)(&t3[0][n][0]); // expected-warning {{cast from 'char *' to 'A *'}}
 154   a = (A *)&t4[n][0];
 155   a = (A *)&t4[n][1]; // expected-warning {{cast from 'char *' to 'A *'}}
 156   a = (A *)(t4 + 1);
 157   a = (A *)(t4 + n);
 158   a = (A *)(static_cast<B1 *>(&t5));
 159   a = (A *)(&(static_cast<B1 &>(t5)));
 160   a = (A *)(static_cast<B0 *>(&t6)); // expected-warning {{cast from 'B0 *' to 'A *'}}
 161   a = (A *)(static_cast<B2 *>(&t7)); // expected-warning {{cast from 'B2 *' to 'A *'}}
 162   a = (A *)(static_cast<B3 *>(&t7));
 163   a = (A *)(static_cast<B2 *>(&t8));  // expected-warning {{cast from 'B2 *' to 'A *'}}
 164   a = (A *)(static_cast<B3 *>(&t8));  // expected-warning {{cast from 'B3 *' to 'A *'}}
 165   a = (A *)(static_cast<D5 *>(&t9));  // expected-warning {{cast from 'D5 *' to 'A *'}}
 166   a = (A *)(static_cast<D3 *>(&t10)); // expected-warning {{cast from 'D3 *' to 'A *'}}
 167 }