xref: /llvm-project/clang/test/Sema/struct-packed-align.c (revision 0f1c1be1968076d6f96f8a7bcc4a15cf195ecd97)
1 // RUN: %clang_cc1 %s -fsyntax-only -verify
2 // RUN: %clang_cc1 %s -fsyntax-only -triple=x86_64-windows-coff -verify
3 // RUN: %clang_cc1 %s -fsyntax-only -triple=x86_64-scei-ps4 -verify
4 // RUN: %clang_cc1 %s -fsyntax-only -triple=x86_64-sie-ps5 -verify
5 
6 // Packed structs.
7 struct s {
8     char a;
9     int b  __attribute__((packed));
10     char c;
11     int d;
12 };
13 
14 extern int a1[sizeof(struct s) == 12 ? 1 : -1];
15 extern int a2[__alignof(struct s) == 4 ? 1 : -1];
16 
17 struct __attribute__((packed)) packed_s {
18     char a;
19     int b  __attribute__((packed));
20     char c;
21     int d;
22 };
23 
24 extern int b1[sizeof(struct packed_s) == 10 ? 1 : -1];
25 extern int b2[__alignof(struct packed_s) == 1 ? 1 : -1];
26 
27 struct fas {
28     char a;
29     int b[];
30 };
31 
32 extern int c1[sizeof(struct fas) == 4 ? 1 : -1];
33 extern int c2[__alignof(struct fas) == 4 ? 1 : -1];
34 
35 struct __attribute__((packed)) packed_fas {
36     char a;
37     int b[];
38 };
39 
40 extern int d1[sizeof(struct packed_fas) == 1 ? 1 : -1];
41 extern int d2[__alignof(struct packed_fas) == 1 ? 1 : -1];
42 
43 struct packed_after_fas {
44     char a;
45     int b[];
46 } __attribute__((packed));
47 
48 extern int d1_2[sizeof(struct packed_after_fas) == 1 ? 1 : -1];
49 extern int d2_2[__alignof(struct packed_after_fas) == 1 ? 1 : -1];
50 
51 // Alignment
52 
53 struct __attribute__((aligned(8))) as1 {
54     char c;
55 };
56 
57 extern int e1[sizeof(struct as1) == 8 ? 1 : -1];
58 extern int e2[__alignof(struct as1) == 8 ? 1 : -1];
59 
60 struct __attribute__((aligned)) as1_2 {
61     char c;
62 };
63 #if ( defined(__s390x__) || ( defined (__ARM_32BIT_STATE) && ! defined(__ANDROID__) ) )
64 extern int e1_2[sizeof(struct as1_2) == 8 ? 1 : -1];
65 extern int e2_2[__alignof(struct as1_2) == 8 ? 1 : -1];
66 #else
67 extern int e1_2[sizeof(struct as1_2) == 16 ? 1 : -1];
68 extern int e2_2[__alignof(struct as1_2) == 16 ? 1 : -1];
69 #endif
70 
71 struct as2 {
72     char c;
73     int __attribute__((aligned(8))) a;
74 };
75 
76 extern int f1[sizeof(struct as2) == 16 ? 1 : -1];
77 extern int f2[__alignof(struct as2) == 8 ? 1 : -1];
78 
79 struct __attribute__((packed)) as3 {
80     char c;
81     int a;
82     int __attribute__((aligned(8))) b;
83 };
84 
85 extern int g1[sizeof(struct as3) == 16 ? 1 : -1];
86 extern int g2[__alignof(struct as3) == 8 ? 1 : -1];
87 
88 
89 struct packedtest {
90   int ted_likes_cheese;
91   void *args[] __attribute__((packed));
92 };
93 
94 // Packed union
95 union __attribute__((packed)) au4 {char c; int x;};
96 extern int h1[sizeof(union au4) == 4 ? 1 : -1];
97 extern int h2[__alignof(union au4) == 1 ? 1 : -1];
98 
99 // Aligned union
100 union au5 {__attribute__((aligned(4))) char c;};
101 extern int h1[sizeof(union au5) == 4 ? 1 : -1];
102 extern int h2[__alignof(union au5) == 4 ? 1 : -1];
103 
104 // Alignment+packed
105 struct as6 {char c; __attribute__((packed, aligned(2))) int x;};
106 extern int i1[sizeof(struct as6) == 6 ? 1 : -1];
107 extern int i2[__alignof(struct as6) == 2 ? 1 : -1];
108 
109 union au6 {char c; __attribute__((packed, aligned(2))) int x;};
110 extern int k1[sizeof(union au6) == 4 ? 1 : -1];
111 extern int k2[__alignof(union au6) == 2 ? 1 : -1];
112 
113 // Check postfix attributes
114 union au7 {char c; int x;} __attribute__((packed));
115 extern int l1[sizeof(union au7) == 4 ? 1 : -1];
116 extern int l2[__alignof(union au7) == 1 ? 1 : -1];
117 
118 struct packed_fas2 {
119     char a;
120     int b[];
121 } __attribute__((packed));
122 
123 extern int m1[sizeof(struct packed_fas2) == 1 ? 1 : -1];
124 extern int m2[__alignof(struct packed_fas2) == 1 ? 1 : -1];
125 
126 // Attribute aligned can round down typedefs.  PR9253
127 typedef long long  __attribute__((aligned(1))) nt;
128 
129 struct nS {
130   char buf_nr;
131   nt start_lba;
132 };
133 
134 #if defined(_WIN32) && !defined(__declspec) // _MSC_VER is unavailable in cc1.
135 // Alignment doesn't affect packing in MS mode.
136 extern int n1[sizeof(struct nS) == 16 ? 1 : -1];
137 extern int n2[__alignof(struct nS) == 8 ? 1 : -1];
138 #else
139 extern int n1[sizeof(struct nS) == 9 ? 1 : -1];
140 extern int n2[__alignof(struct nS) == 1 ? 1 : -1];
141 #endif
142 
143 // Packed attribute shouldn't be ignored for bit-field of char types.
144 // Note from GCC reference manual: The 4.1, 4.2 and 4.3 series of GCC ignore
145 // the packed attribute on bit-fields of type char. This has been fixed in
146 // GCC 4.4 but the change can lead to differences in the structure layout.
147 // See the documentation of -Wpacked-bitfield-compat for more information.
148 struct packed_chars {
149   char a : 8, b : 8, c : 8, d : 4;
150 #ifdef __SCE__
151   // Test for pre-r254596 clang behavior on the PS4/PS5 targets, which must
152   // maintain ABI backwards compatibility.
153   char e : 8 __attribute__((packed));
154   // expected-warning@-1 {{'packed' attribute ignored for field of type 'char'}}
155 #else
156   char e : 8 __attribute__((packed));
157   // expected-warning@-1 {{'packed' attribute was ignored on bit-fields with single-byte alignment in older versions of GCC and Clang}}
158 #endif
159   char f : 4, g : 8, h : 8, i : 8;
160 };
161 
162 #if (defined(_WIN32) || defined(__SCE__)) && !defined(__declspec) // _MSC_VER is unavailable in cc1.
163 // On Windows clang uses MSVC compatible layout in this case.
164 //
165 // Additionally, test for pre-r254596 clang behavior on the PS4/PS5 targets.
166 // They must maintain ABI backwards compatibility.
167 extern int o1[sizeof(struct packed_chars) == 9 ? 1 : -1];
168 extern int o2[__alignof(struct packed_chars) == 1 ? 1 : -1];
169 #elif defined(_AIX)
170 // On AIX, char bitfields have the same alignment as unsigned int.
171 extern int o1[sizeof(struct packed_chars) == 8 ? 1 : -1];
172 extern int o2[__alignof(struct packed_chars) == 4 ? 1 : -1];
173 #else
174 extern int o1[sizeof(struct packed_chars) == 8 ? 1 : -1];
175 extern int o2[__alignof(struct packed_chars) == 1 ? 1 : -1];
176 #endif
177