添加一些语法解析器注释

src/lapi.c

@@ -56,16 +56,20 @@ const char lua_ident[] =
 /*
 ** Convert an acceptable index to a pointer to its respective value.
 ** Non-valid indices return the special nil value 'G(L)->nilvalue'.
+将可接受的索引转换为指向其相应值的指针。无效索引返回特殊的nil值“G（L）->nilvalue”。
 */
 static TValue *index2value (lua_State *L, int idx) {
+  // ci 是当前函数 的上下文 每个函数有自己的栈
   CallInfo *ci = L->ci;
   if (idx > 0) {
+    // idx 大于0是函数调用？
     StkId o = ci->func.p + idx;
     api_check(L, idx <= ci->top.p - (ci->func.p + 1), "unacceptable index");
     if (o >= L->top.p) return &G(L)->nilvalue;
     else return s2v(o);
   }
   else if (!ispseudo(idx)) {  /* negative index */
+    // idx小于等于0是栈顶向下的距离
     api_check(L, idx != 0 && -idx <= L->top.p - (ci->func.p + 1),
                  "invalid index");
     return s2v(L->top.p + idx);

src/lapi.h

@@ -13,6 +13,7 @@
 
 
 /* Increments 'L->top.p', checking for stack overflows */
+// 栈增 check一下是否已满
 #define api_incr_top(L)	{L->top.p++; \
 			 api_check(L, L->top.p <= L->ci->top.p, \
 					"stack overflow");}

src/ldo.c

@@ -311,7 +311,7 @@ void luaD_shrinkstack (lua_State *L) {
   luaE_shrinkCI(L);  /* shrink CI list */
 }
 
-
+// 栈自增 
 void luaD_inctop (lua_State *L) {
   luaD_checkstack(L, 1);
   L->top.p++;
@@ -968,7 +968,7 @@ int luaD_pcall (lua_State *L, Pfunc func, void *u,
 ** Execute a protected parser.
 */
 struct SParser {  /* data to 'f_parser' */
-  ZIO *z;
+  ZIO *z;        // 输入流
   Mbuffer buff;  /* dynamic structure used by the scanner */
   Dyndata dyd;  /* dynamic structures used by the parser */
   const char *mode;
@@ -1001,7 +1001,7 @@ static void f_parser (lua_State *L, void *ud) {
   luaF_initupvals(L, cl);
 }
 
-
+// L 解析器状态，z 输入流
 int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
                                         const char *mode) {
   struct SParser p;

src/lobject.h

@@ -690,7 +690,7 @@ typedef struct Proto {
   { TValue *io = (obj); LClosure *x_ = (x); \
     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VLCL)); \
     checkliveness(L,io); }
-
+// 保存闭包到栈
 #define setclLvalue2s(L,o,cl)	setclLvalue(L,s2v(o),cl)
 
 #define setfvalue(obj,x) \
@@ -766,7 +766,7 @@ typedef union Closure {
   { TValue *io = (obj); Table *x_ = (x); \
     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VTABLE)); \
     checkliveness(L,io); }
-
+// 把表保存到 栈中
 #define sethvalue2s(L,o,h)	sethvalue(L,s2v(o),h)
 
 

src/lparser.c

@@ -61,6 +61,7 @@ typedef struct BlockCnt {
 
 /*
 ** prototypes for recursive non-terminal functions
+递归非终结函数的原型
 */
 static void statement (LexState *ls);
 static void expr (LexState *ls, expdesc *v);
@@ -119,7 +120,7 @@ static void checknext (LexState *ls, int c) {
   luaX_next(ls);
 }
 
-
+// 如果c为null 则输出错误
 #define check_condition(ls,c,msg)	{ if (!(c)) luaX_syntaxerror(ls, msg); }
 
 
@@ -127,6 +128,7 @@ static void checknext (LexState *ls, int c) {
 ** Check that next token is 'what' and skip it. In case of error,
 ** raise an error that the expected 'what' should match a 'who'
 ** in line 'where' (if that is not the current line).
+如果下一个 token 是what 则读取下一个 token ，否则产生一个错误
 */
 static void check_match (LexState *ls, int what, int who, int where) {
   if (l_unlikely(!testnext(ls, what))) {
@@ -140,7 +142,7 @@ static void check_match (LexState *ls, int what, int who, int where) {
   }
 }
 
-
+// 如果下一个token是名称 则解析下一个token
 static TString *str_checkname (LexState *ls) {
   TString *ts;
   check(ls, TK_NAME);
@@ -785,6 +787,7 @@ static void close_func (LexState *ls) {
 ** check whether current token is in the follow set of a block.
 ** 'until' closes syntactical blocks, but do not close scope,
 ** so it is handled in separate.
+检查当前 token 是否在块的后续集合中。'直到'关闭语法块，但不关闭作用域，因此它是单独处理的
 */
 static int block_follow (LexState *ls, int withuntil) {
   switch (ls->t.token) {
@@ -796,7 +799,7 @@ static int block_follow (LexState *ls, int withuntil) {
   }
 }
 
-
+// 主要是这个函数解析脚本
 static void statlist (LexState *ls) {
   /* statlist -> { stat [';'] } */
   while (!block_follow(ls, 1)) {
@@ -987,7 +990,7 @@ static void parlist (LexState *ls) {
   luaK_reserveregs(fs, fs->nactvar);  /* reserve registers for parameters */
 }
 
-
+// 函数的 参数部分, 用 () 包括的部分
 static void body (LexState *ls, expdesc *e, int ismethod, int line) {
   /* body ->  '(' parlist ')' block END */
   FuncState new_fs;
@@ -1192,7 +1195,7 @@ static void simpleexp (LexState *ls, expdesc *v) {
   luaX_next(ls);
 }
 
-
+// 匹配单目运算符
 static UnOpr getunopr (int op) {
   switch (op) {
     case TK_NOT: return OPR_NOT;
@@ -1203,7 +1206,7 @@ static UnOpr getunopr (int op) {
   }
 }
 
-
+// 匹配双目运算符
 static BinOpr getbinopr (int op) {
   switch (op) {
     case '+': return OPR_ADD;
@@ -1257,19 +1260,23 @@ static const struct {
 /*
 ** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
 ** where 'binop' is any binary operator with a priority higher than 'limit'
+读取子表达式 limit 用于限制表达式优先级
 */
 static BinOpr subexpr (LexState *ls, expdesc *v, int limit) {
   BinOpr op;
   UnOpr uop;
   enterlevel(ls);
+  // 如果是单目运算符
   uop = getunopr(ls->t.token);
   if (uop != OPR_NOUNOPR) {  /* prefix (unary) operator? */
     int line = ls->linenumber;
     luaX_next(ls);  /* skip operator */
     subexpr(ls, v, UNARY_PRIORITY);
     luaK_prefix(ls->fs, uop, v, line);
+  } else {
+    // 如果是单目运算符 则执行表达式
+    simpleexp(ls, v);
   }
-  else simpleexp(ls, v);
   /* expand while operators have priorities higher than 'limit' */
   op = getbinopr(ls->t.token);
   while (op != OPR_NOBINOPR && priority[op].left > limit) {
@@ -1287,7 +1294,7 @@ static BinOpr subexpr (LexState *ls, expdesc *v, int limit) {
   return op;  /* return first untreated operator */
 }
 
-
+// 读取表达式
 static void expr (LexState *ls, expdesc *v) {
   subexpr(ls, v, 0);
 }
@@ -1635,7 +1642,7 @@ static void forstat (LexState *ls, int line) {
   leaveblock(fs);  /* loop scope ('break' jumps to this point) */
 }
 
-
+// 解析 if 或 elseif 到 then 之间的语句块
 static void test_then_block (LexState *ls, int *escapelist) {
   /* test_then_block -> [IF | ELSEIF] cond THEN block */
   BlockCnt bl;
@@ -1672,7 +1679,7 @@ static void test_then_block (LexState *ls, int *escapelist) {
   luaK_patchtohere(fs, jf);
 }
 
-
+// if 语句块
 static void ifstat (LexState *ls, int line) {
   /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
   FuncState *fs = ls->fs;
@@ -1842,12 +1849,13 @@ static void retstat (LexState *ls) {
   testnext(ls, ';');  /* skip optional semicolon */
 }
 
-
+// 解析token
 static void statement (LexState *ls) {
   int line = ls->linenumber;  /* may be needed for error messages */
   enterlevel(ls);
   switch (ls->t.token) {
     case ';': {  /* stat -> ';' (empty statement) */
+      // 分号什么也不做 直接解析下一个 token
       luaX_next(ls);  /* skip ';' */
       break;
     }
@@ -1948,6 +1956,7 @@ LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
   setclLvalue2s(L, L->top.p, cl);  /* anchor it (to avoid being collected) */
   luaD_inctop(L);
   lexstate.h = luaH_new(L);  /* create table for scanner */
+  // 把这个表保存到栈顶？
   sethvalue2s(L, L->top.p, lexstate.h);  /* anchor it */
   luaD_inctop(L);
   funcstate.f = cl->p = luaF_newproto(L);
@@ -1958,6 +1967,7 @@ LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
   lexstate.dyd = dyd;
   dyd->actvar.n = dyd->gt.n = dyd->label.n = 0;
   luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar);
+  // 把这个输入流当作一个函数来调用
   mainfunc(&lexstate, &funcstate);
   lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs);
   /* all scopes should be correctly finished */

src/lparser.h

@@ -81,7 +81,7 @@ typedef enum {
 // 已编号的变量
 #define vkisindexed(k)	(VINDEXED <= (k) && (k) <= VINDEXSTR)
 
-
+// 定义表达式数据结构
 typedef struct expdesc {
   expkind k;
   union {

src/lzio.c

@@ -35,7 +35,7 @@ int luaZ_fill (ZIO *z) {
   return cast_uchar(*(z->p++));
 }
 
-
+// 初始化输入流
 void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
   z->L = L;
   z->reader = reader;

src/lzio.h

@@ -14,7 +14,7 @@
 
 
 #define EOZ	(-1)			/* end of stream */
-
+// 输入流
 typedef struct Zio ZIO;
 
 // 获取下一个字符
@@ -52,7 +52,7 @@ LUAI_FUNC size_t luaZ_read (ZIO* z, void *b, size_t n);	/* read next n bytes */
 
 
 /* --------- Private Part ------------------ */
-
+// 输入流
 struct Zio {
   size_t n;			/* bytes still unread */
   const char *p;		/* current position in buffer */