lua.5.2.3源码阅读(02)：字符串对象

 1 /* type to ensure maximum alignment */
 2 #if !defined(LUAI_USER_ALIGNMENT_T)
 3 #define LUAI_USER_ALIGNMENT_T    union { double u; void *s; long l; }
 4 #endif
 5 
 6 typedef LUAI_USER_ALIGNMENT_T L_Umaxalign;
 7 
 8 /*
 9 ** Header for string value; string bytes follow the end of this structure
10 */
11 typedef union TString {
12   L_Umaxalign dummy;  /* ensures maximum alignment for strings */
13   struct {
14     CommonHeader;
15     lu_byte extra;  /* reserved words for short strings; "has hash" for longs */
16     unsigned int hash;
17     size_t len;  /* number of characters in string */
18   } tsv;
19 } TString;
20 
21 /*
22 ** Common Header for all collectable objects (in macro form, to be
23 ** included in other objects)
24 */
25 #define CommonHeader    GCObject *next; lu_byte tt; lu_byte marked

1   struct {
2     GCObject *next; 
3     lu_byte tt; 
4     lu_byte marked;
5     lu_byte extra;  /* reserved words for short strings; "has hash" for longs */
6     unsigned int hash;
7     size_t len;  /* number of characters in string */
8   } tsv;