clang/test/Analysis/padding_c.c

   1 // FIXME -Wno-aix-compat added temporarily while the diagnostic is being
   2 // refined.
   3 // RUN: %clang_analyze_cc1 -verify -Wno-aix-compat %s \
   4 // RUN:   -analyzer-checker=optin.performance \
   5 // RUN:   -analyzer-config optin.performance.Padding:AllowedPad=2
   6
   7 // RUN: not %clang_analyze_cc1 -verify -Wno-aix-compat %s \
   8 // RUN:   -analyzer-checker=core \
   9 // RUN:   -analyzer-checker=optin.performance.Padding \
  10 // RUN:   -analyzer-config optin.performance.Padding:AllowedPad=-10 \
  11 // RUN:   2>&1 | FileCheck %s -check-prefix=CHECK-PAD-NEGATIVE-VALUE
  12
  13 // CHECK-PAD-NEGATIVE-VALUE: (frontend): invalid input for checker option
  14 // CHECK-PAD-NEGATIVE-VALUE-SAME: 'optin.performance.Padding:AllowedPad', that
  15 // CHECK-PAD-NEGATIVE-VALUE-SAME: expects a non-negative value
  16
  17 #if __has_include(<stdalign.h>)
  18 #include <stdalign.h>
  19 #endif
  20
  21 #if __has_include(<stdalign.h>) || defined(__cplusplus)
  22 // expected-warning@+1{{Excessive padding in 'struct FieldAttrAlign' (6 padding}}
  23 struct FieldAttrAlign {
  24   char c1;
  25   alignas(4) int i;
  26   char c2;
  27 };
  28
  29 // expected-warning@+1{{Excessive padding in 'struct FieldAttrOverAlign' (10 padding}}
  30 struct FieldAttrOverAlign {
  31   char c1;
  32   alignas(8) int i;
  33   char c2;
  34 };
  35
  36 #endif // __has_include(<stdalign.h>) || defined(__cplusplus)
  37
  38 // Re-ordering members of these structs won't reduce padding, so don't warn
  39 struct LeadingChar { // no-warning
  40   char c;
  41   int i;
  42 };
  43
  44 struct TrailingChar { // no-warning
  45   int i;
  46   char c;
  47 };
  48
  49 struct Helpless { // no-warning
  50   struct TrailingChar i1;
  51   struct LeadingChar i2;
  52   char c;
  53 };
  54
  55 #pragma pack(push)
  56 #pragma pack(1)
  57 struct SquishedIntSandwich { // no-warning
  58   char c1;
  59   int i;
  60   char c2;
  61 };
  62 #pragma pack(pop)
  63
  64 // Re-ordering members of these structs will reduce padding, so warn
  65 struct IntSandwich { // expected-warning{{Excessive padding in 'struct IntSandwich'}}
  66   char c1;
  67   int i;
  68   char c2;
  69 };
  70
  71 struct TurDuckHen { // expected-warning{{Excessive padding in 'struct TurDuckHen'}}
  72   char c1;
  73   struct IntSandwich i;
  74   char c2;
  75 };
  76
  77 #pragma pack(push)
  78 #pragma pack(2)
  79 struct SmallIntSandwich { // expected-warning{{Excessive padding in 'struct SmallIntSandwich'}}
  80   char c1;
  81   int i1;
  82   char c2;
  83   int i2;
  84   char c3;
  85   int i3;
  86   char c4;
  87 };
  88 #pragma pack(pop)
  89
  90 union SomeUnion { // no-warning
  91   char c;
  92   short s;
  93   int i;
  94 };
  95
  96 struct HoldsAUnion { // expected-warning{{Excessive padding in 'struct HoldsAUnion'}}
  97   char c1;
  98   union SomeUnion u;
  99   char c2;
 100 };
 101
 102 struct BigCharArray { // no-warning
 103   char c[129];
 104 };
 105
 106 struct SmallCharArray { // no-warning
 107   char c[5];
 108 };
 109
 110 struct MediumIntArray { // no-warning
 111   int i[5];
 112 };
 113
 114 struct LargeSizeToSmallSize { // expected-warning{{Excessive padding in 'struct LargeSizeToSmallSize'}}
 115   struct BigCharArray b;
 116   struct MediumIntArray m;
 117   struct SmallCharArray s;
 118 };
 119
 120 struct LargeAlignToSmallAlign { // no-warning
 121   struct MediumIntArray m;
 122   struct BigCharArray b;
 123   struct SmallCharArray s;
 124 };
 125
 126 // Currently ignoring VLA padding problems.  Still need to make sure we don't
 127 // choke on VLAs though
 128 struct HoldsVLA { // no-warning
 129   char c1;
 130   int x;
 131   char c2;
 132   int vla[];
 133 };
 134
 135 // Currently ignoring bitfield padding problems.  Still need to make sure we
 136 // don't choke on bitfields though
 137 struct HoldsBitfield { // no-warning
 138   char c1;
 139   int x;
 140   char c2;
 141   unsigned char b1 : 3;
 142   unsigned char b2 : 3;
 143   unsigned char b3 : 2;
 144 };
 145
 146 typedef struct { // expected-warning{{Excessive padding in 'TypedefSandwich'}}
 147   char c1;
 148   int i;
 149   char c2;
 150 } TypedefSandwich;
 151
 152 // expected-warning@+1{{Excessive padding in 'struct StructAttrAlign' (10 padding}}
 153 struct StructAttrAlign {
 154   char c1;
 155   int i;
 156   char c2;
 157 } __attribute__((aligned(8)));
 158
 159 struct CorrectOverlyAlignedChar { // no-warning
 160   char c __attribute__((aligned(4096)));
 161   char c1;
 162   int x1;
 163   char c2;
 164   int x2;
 165   char c3;
 166 };
 167
 168 struct OverlyAlignedChar { // expected-warning{{Excessive padding in 'struct OverlyAlignedChar'}}
 169   char c1;
 170   int x;
 171   char c2;
 172   char c __attribute__((aligned(4096)));
 173 };
 174
 175 struct HoldsOverlyAlignedChar { // expected-warning{{Excessive padding in 'struct HoldsOverlyAlignedChar'}}
 176   char c1;
 177   struct OverlyAlignedChar o;
 178   char c2;
 179 };
 180
 181 void internalStructFunc(void) {
 182   struct X { // expected-warning{{Excessive padding in 'struct X'}}
 183     char c1;
 184     int t;
 185     char c2;
 186   };
 187   struct X obj;
 188 }
 189
 190 void typedefStructFunc(void) {
 191   typedef struct { // expected-warning{{Excessive padding in 'S'}}
 192     char c1;
 193     int t;
 194     char c2;
 195   } S;
 196   S obj;
 197 }
 198
 199 void anonStructFunc(void) {
 200   struct { // expected-warning{{Excessive padding in 'struct (unnamed}}
 201     char c1;
 202     int t;
 203     char c2;
 204   } obj;
 205 }
 206
 207 struct CorrectDefaultAttrAlign { // no-warning
 208   long long i;
 209   char c1;
 210   char c2;
 211 } __attribute__((aligned));
 212
 213 struct TooSmallShortSandwich { // no-warning
 214   char c1;
 215   short s;
 216   char c2;
 217 };
 218
 219 // expected-warning@+1{{Excessive padding in 'struct SmallArrayShortSandwich'}}
 220 struct SmallArrayShortSandwich {
 221   char c1;
 222   short s;
 223   char c2;
 224 } ShortArray[20];
 225
 226 // expected-warning@+1{{Excessive padding in 'struct SmallArrayInFunc'}}
 227 struct SmallArrayInFunc {
 228   char c1;
 229   short s;
 230   char c2;
 231 };
 232
 233 void arrayHolder(void) {
 234   struct SmallArrayInFunc Arr[15];
 235 }
 236
 237 // xxxexpected-warning@+1{{Excessive padding in 'struct SmallArrayInStruct'}}
 238 struct SmallArrayInStruct {
 239   char c1;
 240   short s;
 241   char c2;
 242 };
 243
 244 struct HoldsSmallArray {
 245   struct SmallArrayInStruct Field[20];
 246 } HoldsSmallArrayElt;
 247
 248 void nestedPadding(void) {
 249   struct HoldsSmallArray Arr[15];
 250 }