xref: /aosp_15_r20/external/clang/test/CodeGen/union-init.c (revision 67e74705e28f6214e480b399dd47ea732279e315)
1*67e74705SXin Li // RUN: %clang_cc1 -emit-llvm < %s -o -
2*67e74705SXin Li 
3*67e74705SXin Li // A nice and complicated initialization example with unions from Python
4*67e74705SXin Li typedef int Py_ssize_t;
5*67e74705SXin Li 
6*67e74705SXin Li typedef union _gc_head {
7*67e74705SXin Li   struct {
8*67e74705SXin Li     union _gc_head *gc_next;
9*67e74705SXin Li     union _gc_head *gc_prev;
10*67e74705SXin Li     Py_ssize_t gc_refs;
11*67e74705SXin Li   } gc;
12*67e74705SXin Li   long double dummy;  /* force worst-case alignment */
13*67e74705SXin Li } PyGC_Head;
14*67e74705SXin Li 
15*67e74705SXin Li struct gc_generation {
16*67e74705SXin Li   PyGC_Head head;
17*67e74705SXin Li   int threshold; /* collection threshold */
18*67e74705SXin Li   int count;     /* count of allocations or collections of younger
19*67e74705SXin Li                     generations */
20*67e74705SXin Li };
21*67e74705SXin Li 
22*67e74705SXin Li #define NUM_GENERATIONS 3
23*67e74705SXin Li #define GEN_HEAD(n) (&generations[n].head)
24*67e74705SXin Li 
25*67e74705SXin Li /* linked lists of container objects */
26*67e74705SXin Li struct gc_generation generations[NUM_GENERATIONS] = {
27*67e74705SXin Li   /* PyGC_Head,                     threshold,      count */
28*67e74705SXin Li   {{{GEN_HEAD(0), GEN_HEAD(0), 0}}, 700,            0},
29*67e74705SXin Li   {{{GEN_HEAD(1), GEN_HEAD(1), 0}},  10,            0},
30*67e74705SXin Li   {{{GEN_HEAD(2), GEN_HEAD(2), 0}},  10,            0},
31*67e74705SXin Li };
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