commit for once

1 files changed, 30 insertions, 0 deletions

diff --git a/3/9_data_structures/41_struct_test.c b/3/9_data_structures/41_struct_test.c
new file mode 100644
index 0000000..1816b31
--- /dev/null
+++ b/3/9_data_structures/41_struct_test.c
@@ -0,0 +1,30 @@
+struct test {
+    short *p;
+    struct {
+        short x;
+        short y;
+    } s;
+    struct test *next;
+}
+
+// A.
+//      p: 0, it's at the beginning of the struct
+//      s.x: (length p) <- 8
+//      s.y: (length p) + (length s.x) <- 10
+//      next: (length p) + (length s.x) + (length s.y) <- 12
+// B.
+//      total bytes should be 20. pointer + short + short + pointer
+// C.
+//  st in %rdi
+//  st_init:
+//      movl 8(%rdi), %eax
+//      movl %eax, 10(%rdi)
+//      leaq 10(%rdi), %rax
+//      movq %rax, (%rdi)
+//      movq %rdi, 12(%rdi)
+//      ret
+void st_init(struct test *st) {
+    st->s.y = st->s.x;
+    st->p = &(st->s.y);
+    st->next = st;
+}