clang/test/Sema/test-wunaligned-access.cpp

   1 // RUN: %clang_cc1 %s -triple=armv7-none-none-eabi -verify -Wunaligned-access -S -emit-llvm -o %t
   2 // REQUIRES: arm-registered-target
   3 //
   4 // This test suite tests the warning triggered by the -Wunaligned-access option.
   5 // The warning occurs when a struct or other type of record contains a field
   6 // that is itself a record. The outer record must be a packed structure, while
   7 // while the inner record must be unpacked. This is the fundamental condition
   8 // for the warning to be triggered. Some of these tests may have three layers.
   9 //
  10 // The command line option -fsyntax-only is not used as Clang needs to be
  11 // forced to layout the structs used in this test.
  12 // The triple in the command line above is used for the assumptions about
  13 // size and alignment of types.
  14
  15 // Packed-Unpacked Tests (No Pragma)
  16
  17 struct T1 {
  18   char a;
  19   int b;
  20 };
  21
  22 struct __attribute__((packed)) U1 {
  23   char a;
  24   T1 b; // expected-warning {{field b within 'U1' is less aligned than 'T1' and is usually due to 'U1' being packed, which can lead to unaligned accesses}}
  25   int c;
  26 };
  27
  28 struct __attribute__((packed)) U2 {
  29   char a;
  30   T1 b __attribute__((aligned(4)));
  31   int c;
  32 };
  33
  34 struct __attribute__((packed)) U3 {
  35   char a;
  36   char b;
  37   short c;
  38   T1 d;
  39 };
  40
  41 struct __attribute__((packed)) U4 {
  42   T1 a;
  43   int b;
  44 };
  45
  46 struct __attribute__((aligned(4), packed)) U5 {
  47   char a;
  48   T1 b; // expected-warning {{field b within 'U5' is less aligned than 'T1' and is usually due to 'U5' being packed, which can lead to unaligned accesses}}
  49   int c;
  50 };
  51
  52 struct __attribute__((aligned(4), packed)) U6 {
  53   char a;
  54   char b;
  55   short c;
  56   T1 d;
  57 };
  58
  59 // Packed-Unpacked Tests with Pragma
  60
  61 #pragma pack(push, 1)
  62
  63 struct __attribute__((packed)) U7 {
  64   char a;
  65   T1 b; // expected-warning {{field b within 'U7' is less aligned than 'T1' and is usually due to 'U7' being packed, which can lead to unaligned accesses}}
  66   int c;
  67 };
  68
  69 struct __attribute__((packed)) U8 {
  70   char a;
  71   T1 b __attribute__((aligned(4))); // expected-warning {{field b within 'U8' is less aligned than 'T1' and is usually due to 'U8' being packed, which can lead to unaligned accesses}}
  72   int c;
  73 };
  74
  75 struct __attribute__((aligned(4))) U9 {
  76   char a;
  77   T1 b; // expected-warning {{field b within 'U9' is less aligned than 'T1' and is usually due to 'U9' being packed, which can lead to unaligned accesses}}
  78   int c;
  79 };
  80
  81 struct U10 {
  82   char a;
  83   T1 b; // expected-warning {{field b within 'U10' is less aligned than 'T1' and is usually due to 'U10' being packed, which can lead to unaligned accesses}}
  84   int c;
  85 };
  86
  87 #pragma pack(pop)
  88
  89 // Packed-Packed Tests
  90
  91 struct __attribute__((packed)) T2 {
  92   char a;
  93   int b;
  94 };
  95
  96 struct __attribute__((packed)) U11 {
  97   char a;
  98   T2 b;
  99   int c;
 100 };
 101
 102 #pragma pack(push, 1)
 103 struct U12 {
 104   char a;
 105   T2 b;
 106   int c;
 107 };
 108 #pragma pack(pop)
 109
 110 // Unpacked-Packed Tests
 111
 112 struct U13 {
 113   char a;
 114   T2 b;
 115   int c;
 116 };
 117
 118 struct U14 {
 119   char a;
 120   T2 b __attribute__((aligned(4)));
 121   int c;
 122 };
 123
 124 // Unpacked-Unpacked Test
 125
 126 struct T3 {
 127   char a;
 128   int b;
 129 };
 130
 131 struct U15 {
 132   char a;
 133   T3 b;
 134   int c;
 135 };
 136
 137 // Packed-Packed-Unpacked Test (No pragma)
 138
 139 struct __attribute__((packed)) A1 {
 140   char a;
 141   T1 b; // expected-warning {{field b within 'A1' is less aligned than 'T1' and is usually due to 'A1' being packed, which can lead to unaligned accesses}}
 142 };
 143
 144 struct __attribute__((packed)) U16 {
 145   char a;
 146   A1 b;
 147   int c;
 148 };
 149
 150 struct __attribute__((packed)) A2 {
 151   char a;
 152   T1 b __attribute__((aligned(4)));
 153 };
 154
 155 struct __attribute__((packed)) U17 {
 156   char a;
 157   A2 b; // expected-warning {{field b within 'U17' is less aligned than 'A2' and is usually due to 'U17' being packed, which can lead to unaligned accesses}}
 158   int c;
 159 };
 160
 161 // Packed-Unpacked-Packed tests
 162
 163 struct A3 {
 164   char a;
 165   T2 b;
 166 };
 167
 168 struct __attribute__((packed)) U18 {
 169   char a;
 170   A3 b;
 171   int c;
 172 };
 173
 174 struct A4 {
 175   char a;
 176   T2 b;
 177   int c;
 178 };
 179
 180 #pragma pack(push, 1)
 181 struct U19 {
 182   char a;
 183   A4 b; // expected-warning {{field b within 'U19' is less aligned than 'A4' and is usually due to 'U19' being packed, which can lead to unaligned accesses}}
 184   int c;
 185 };
 186 #pragma pack(pop)
 187
 188 // Packed-Unpacked-Unpacked tests
 189
 190 struct A5 {
 191   char a;
 192   T1 b;
 193 };
 194
 195 struct __attribute__((packed)) U20 {
 196   char a;
 197   A5 b; // expected-warning {{field b within 'U20' is less aligned than 'A5' and is usually due to 'U20' being packed, which can lead to unaligned accesses}}
 198   int c;
 199 };
 200
 201 struct A6 {
 202   char a;
 203   T1 b;
 204 };
 205
 206 #pragma pack(push, 1)
 207 struct U21 {
 208   char a;
 209   A6 b; // expected-warning {{field b within 'U21' is less aligned than 'A6' and is usually due to 'U21' being packed, which can lead to unaligned accesses}}
 210   int c;
 211 };
 212 #pragma pack(pop)
 213
 214 // Unpacked-Packed-Packed test
 215
 216 struct __attribute__((packed)) A7 {
 217   char a;
 218   T2 b;
 219 };
 220
 221 struct U22 {
 222   char a;
 223   A7 b;
 224   int c;
 225 };
 226
 227 // Unpacked-Packed-Unpacked tests
 228
 229 struct __attribute__((packed)) A8 {
 230   char a;
 231   T1 b; // expected-warning {{field b within 'A8' is less aligned than 'T1' and is usually due to 'A8' being packed, which can lead to unaligned accesses}}
 232 };
 233
 234 struct U23 {
 235   char a;
 236   A8 b;
 237   int c;
 238 };
 239
 240 struct __attribute__((packed)) A9 {
 241   char a;
 242   T1 b __attribute__((aligned(4)));
 243 };
 244
 245 struct U24 {
 246   char a;
 247   A9 b;
 248   int c;
 249 };
 250
 251 struct U1 s1;
 252 struct U2 s2;
 253 struct U3 s3;
 254 struct U4 s4;
 255 struct U5 s5;
 256 struct U6 s6;
 257 struct U7 s7;
 258 struct U8 s8;
 259 struct U9 s9;
 260 struct U10 s10;
 261 struct U11 s11;
 262 struct U12 s12;
 263 struct U13 s13;
 264 struct U14 s14;
 265 struct U15 s15;
 266 struct U16 s16;
 267 struct U17 s17;
 268 struct U18 s18;
 269 struct U19 s19;
 270 struct U20 s20;
 271 struct U21 s21;
 272 struct U22 s22;
 273 struct U23 s23;
 274 struct U24 s24;