clang/test/Analysis/padding_c.c

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