1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
|
// RUN: %clang_analyze_cc1 -triple x86_64-unknown-linux -std=c++14 -analyzer-checker=optin.performance -analyzer-config optin.performance.Padding:AllowedPad=2 -verify %s
// expected-warning@+7{{\
Excessive padding in 'struct IntSandwich' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
i, \
c1, \
c2, \
}}
struct IntSandwich {
char c1;
int i;
char c2;
};
// expected-warning@+7{{\
Excessive padding in 'struct TurDuckHen' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
i, \
c1, \
c2, \
}}
struct TurDuckHen {
char c1;
struct IntSandwich i;
char c2;
};
#pragma pack(push)
#pragma pack(2)
// expected-warning@+11{{\
Excessive padding in 'struct SmallIntSandwich' (4 padding bytes, where 0 is optimal). \
Optimal fields order: \
i1, \
i2, \
i3, \
c1, \
c2, \
c3, \
c4, \
}}
struct SmallIntSandwich {
char c1;
int i1;
char c2;
int i2;
char c3;
int i3;
char c4;
};
#pragma pack(pop)
union SomeUnion { // no-warning
char c;
short s;
int i;
};
// expected-warning@+7{{\
Excessive padding in 'struct HoldsAUnion' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
u, \
c1, \
c2, \
}}
struct HoldsAUnion {
char c1;
union SomeUnion u;
char c2;
};
struct SmallCharArray { // no-warning
char c[5];
};
struct MediumIntArray { // no-warning
int i[5];
};
// expected-warning@+7{{\
Excessive padding in 'struct StructSandwich' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
m, \
s, \
s2, \
}}
struct StructSandwich {
struct SmallCharArray s;
struct MediumIntArray m;
struct SmallCharArray s2;
};
// expected-warning@+7{{\
Excessive padding in 'TypedefSandwich' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
i, \
c1, \
c2, \
}}
typedef struct {
char c1;
int i;
char c2;
} TypedefSandwich;
// expected-warning@+7{{\
Excessive padding in 'struct StructAttrAlign' (10 padding bytes, where 2 is optimal). \
Optimal fields order: \
i, \
c1, \
c2, \
}}
struct StructAttrAlign {
char c1;
int i;
char c2;
} __attribute__((aligned(8)));
// expected-warning@+8{{\
Excessive padding in 'struct OverlyAlignedChar' (8185 padding bytes, where 4089 is optimal). \
Optimal fields order: \
c, \
c1, \
c2, \
x, \
}}
struct OverlyAlignedChar {
char c1;
int x;
char c2;
char c __attribute__((aligned(4096)));
};
// expected-warning@+7{{\
Excessive padding in 'struct HoldsOverlyAlignedChar' (8190 padding bytes, where 4094 is optimal). \
Optimal fields order: \
o, \
c1, \
c2, \
}}
struct HoldsOverlyAlignedChar {
char c1;
struct OverlyAlignedChar o;
char c2;
};
void internalStructFunc() {
// expected-warning@+7{{\
Excessive padding in 'struct X' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
t, \
c1, \
c2, \
}}
struct X {
char c1;
int t;
char c2;
};
struct X obj;
}
void typedefStructFunc() {
// expected-warning@+7{{\
Excessive padding in 'S' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
t, \
c1, \
c2, \
}}
typedef struct {
char c1;
int t;
char c2;
} S;
S obj;
}
// expected-warning@+7{{\
Excessive padding in 'struct DefaultAttrAlign' (22 padding bytes, where 6 is optimal). \
Optimal fields order: \
i, \
c1, \
c2, \
}}
struct DefaultAttrAlign {
char c1;
long long i;
char c2;
} __attribute__((aligned));
// expected-warning@+7{{\
Excessive padding in 'struct SmallArrayShortSandwich' (2 padding bytes, where 0 is optimal). \
Optimal fields order: \
s, \
c1, \
c2, \
}}
struct SmallArrayShortSandwich {
char c1;
short s;
char c2;
} ShortArray[20];
// expected-warning@+7{{\
Excessive padding in 'struct SmallArrayInFunc' (2 padding bytes, where 0 is optimal). \
Optimal fields order: \
s, \
c1, \
c2, \
}}
struct SmallArrayInFunc {
char c1;
short s;
char c2;
};
void arrayHolder() {
struct SmallArrayInFunc Arr[15];
}
// expected-warning@+7{{\
Excessive padding in 'class VirtualIntSandwich' (10 padding bytes, where 2 is optimal). \
Optimal fields order: \
i, \
c1, \
c2, \
}}
class VirtualIntSandwich {
virtual void foo() {}
char c1;
int i;
char c2;
};
// constructed so as not to have tail padding
// expected-warning@+8{{\
Excessive padding in 'class InnerPaddedB' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
i1, \
i2, \
c1, \
c2, \
}}
class InnerPaddedB {
char c1;
int i1;
char c2;
int i2;
};
class Empty {}; // no-warning
// expected-warning@+7{{\
Excessive padding in 'class LotsOfSpace' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
i, \
e1, \
e2, \
}}
class LotsOfSpace {
Empty e1;
int i;
Empty e2;
};
// expected-warning@+7{{\
Excessive padding in 'TypedefSandwich2' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
t, \
c1, \
c2, \
}}
typedef struct {
char c1;
// expected-warning@+7{{\
Excessive padding in 'TypedefSandwich2::NestedTypedef' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
i, \
c1, \
c2, \
}}
typedef struct {
char c1;
int i;
char c2;
} NestedTypedef;
NestedTypedef t;
char c2;
} TypedefSandwich2;
template <typename T>
struct Foo {
// expected-warning@+7{{\
Excessive padding in 'struct Foo<int>::Nested' (6 padding bytes, where 2 is optimal). \
Optimal fields order: \
t, \
c1, \
c2, \
}}
struct Nested {
char c1;
T t;
char c2;
};
};
struct Holder { // no-warning
Foo<int>::Nested t1;
Foo<char>::Nested t2;
};
|
