1 // RUN: %check_clang_tidy %s altera-struct-pack-align %t -- -header-filter=.*
2
3 // Struct needs both alignment and packing
4 struct error {
5 char a;
6 double b;
7 char c;
8 };
9 // CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct 'error' is inefficient due to padding; only needs 10 bytes but is using 24 bytes [altera-struct-pack-align]
10 // CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((packed))" to reduce the amount of padding applied to struct 'error'
11 // CHECK-MESSAGES: :[[@LINE-7]]:8: warning: accessing fields in struct 'error' is inefficient due to poor alignment; currently aligned to 8 bytes, but recommended alignment is 16 bytes [altera-struct-pack-align]
12 // CHECK-MESSAGES: :[[@LINE-8]]:8: note: use "__attribute__((aligned(16)))" to align struct 'error' to 16 bytes
13 // CHECK-FIXES: __attribute__((packed))
14 // CHECK-FIXES: __attribute__((aligned(16)));
15
16 // Struct is explicitly packed, but needs alignment
17 struct error_packed {
18 char a;
19 double b;
20 char c;
21 } __attribute__((packed));
22 // CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct 'error_packed' is inefficient due to poor alignment; currently aligned to 1 bytes, but recommended alignment is 16 bytes [altera-struct-pack-align]
23 // CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((aligned(16)))" to align struct 'error_packed' to 16 bytes
24 // CHECK-FIXES: __attribute__((aligned(16)))
25
26 // Struct is properly packed, but needs alignment
27 struct align_only {
28 char a;
29 char b;
30 char c;
31 char d;
32 int e;
33 double f;
34 };
35 // CHECK-MESSAGES: :[[@LINE-8]]:8: warning: accessing fields in struct 'align_only' is inefficient due to poor alignment; currently aligned to 8 bytes, but recommended alignment is 16 bytes [altera-struct-pack-align]
36 // CHECK-MESSAGES: :[[@LINE-9]]:8: note: use "__attribute__((aligned(16)))" to align struct 'align_only' to 16 bytes
37 // CHECK-FIXES: __attribute__((aligned(16)));
38
39 // Struct is perfectly packed but wrongly aligned
40 struct bad_align {
41 char a;
42 double b;
43 char c;
44 } __attribute__((packed)) __attribute__((aligned(8)));
45 // CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct 'bad_align' is inefficient due to poor alignment; currently aligned to 8 bytes, but recommended alignment is 16 bytes [altera-struct-pack-align]
46 // CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((aligned(16)))" to align struct 'bad_align' to 16 bytes
47 // CHECK-FIXES: __attribute__((aligned(16)));
48
49 struct bad_align2 {
50 char a;
51 double b;
52 char c;
53 } __attribute__((packed)) __attribute__((aligned(32)));
54 // CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct 'bad_align2' is inefficient due to poor alignment; currently aligned to 32 bytes, but recommended alignment is 16 bytes [altera-struct-pack-align]
55 // CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((aligned(16)))" to align struct 'bad_align2' to 16 bytes
56 // CHECK-FIXES: __attribute__((aligned(16)));
57
58 struct bad_align3 {
59 char a;
60 double b;
61 char c;
62 } __attribute__((packed)) __attribute__((aligned(4)));
63 // CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct 'bad_align3' is inefficient due to poor alignment; currently aligned to 4 bytes, but recommended alignment is 16 bytes [altera-struct-pack-align]
64 // CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((aligned(16)))" to align struct 'bad_align3' to 16 bytes
65 // CHECK-FIXES: __attribute__((aligned(16)));
66
67 // Struct is both perfectly packed and aligned
68 struct success {
69 char a;
70 double b;
71 char c;
72 } __attribute__((packed)) __attribute__((aligned(16)));
73 //Should take 10 bytes and be aligned to 16 bytes
74
75 // Struct is properly packed, and explicitly aligned
76 struct success2 {
77 int a;
78 int b;
79 int c;
80 } __attribute__((aligned(16)));
81
82 // If struct is properly aligned, packing not needed
83 struct success3 {
84 char a;
85 double b;
86 char c;
87 } __attribute__((aligned(16)));
88
89 // If struct is templated, warnings should not be triggered
90 template <typename A, typename B>
91 struct success4 {
92 A a;
93 B b;
94 int c;
95 };
96
97 // Warnings should not trigger on struct instantiations
no_trigger_on_instantiation()98 void no_trigger_on_instantiation() {
99 struct bad_align3 instantiated { 'a', 0.001, 'b' };
100 }
101
102