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1866
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1 /*
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2 ** $Id: lparser.c,v 2.130 2013/02/06 13:37:39 roberto Exp $
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3 ** Lua Parser
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4 ** See Copyright Notice in lua.h
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5 */
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6
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7
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8 #include <string.h>
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9
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10 #define lparser_c
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11 #define LUA_CORE
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12
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13 #include "lua.h"
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14
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15 #include "lcode.h"
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16 #include "ldebug.h"
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17 #include "ldo.h"
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18 #include "lfunc.h"
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19 #include "llex.h"
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20 #include "lmem.h"
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21 #include "lobject.h"
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22 #include "lopcodes.h"
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23 #include "lparser.h"
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24 #include "lstate.h"
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25 #include "lstring.h"
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26 #include "ltable.h"
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27
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28
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29
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30 /* maximum number of local variables per function (must be smaller
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31 than 250, due to the bytecode format) */
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32 #define MAXVARS 200
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33
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34
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35 #define hasmultret(k) ((k) == VCALL || (k) == VVARARG)
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36
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37
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38
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39 /*
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40 ** nodes for block list (list of active blocks)
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41 */
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42 typedef struct BlockCnt {
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43 struct BlockCnt *previous; /* chain */
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44 short firstlabel; /* index of first label in this block */
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45 short firstgoto; /* index of first pending goto in this block */
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46 lu_byte nactvar; /* # active locals outside the block */
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47 lu_byte upval; /* true if some variable in the block is an upvalue */
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48 lu_byte isloop; /* true if `block' is a loop */
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49 } BlockCnt;
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50
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51
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52
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53 /*
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54 ** prototypes for recursive non-terminal functions
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55 */
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56 static void statement (LexState *ls);
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57 static void expr (LexState *ls, expdesc *v);
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58
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59
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60 static void anchor_token (LexState *ls) {
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61 /* last token from outer function must be EOS */
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62 lua_assert(ls->fs != NULL || ls->t.token == TK_EOS);
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63 if (ls->t.token == TK_NAME || ls->t.token == TK_STRING) {
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64 TString *ts = ls->t.seminfo.ts;
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65 luaX_newstring(ls, getstr(ts), ts->tsv.len);
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66 }
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67 }
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68
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69
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70 /* semantic error */
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71 static l_noret semerror (LexState *ls, const char *msg) {
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72 ls->t.token = 0; /* remove 'near to' from final message */
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73 luaX_syntaxerror(ls, msg);
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74 }
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75
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76
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77 static l_noret error_expected (LexState *ls, int token) {
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78 luaX_syntaxerror(ls,
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79 luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token)));
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80 }
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81
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82
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83 static l_noret errorlimit (FuncState *fs, int limit, const char *what) {
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84 lua_State *L = fs->ls->L;
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85 const char *msg;
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86 int line = fs->f->linedefined;
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87 const char *where = (line == 0)
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88 ? "main function"
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89 : luaO_pushfstring(L, "function at line %d", line);
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90 msg = luaO_pushfstring(L, "too many %s (limit is %d) in %s",
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91 what, limit, where);
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92 luaX_syntaxerror(fs->ls, msg);
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93 }
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94
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95
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96 static void checklimit (FuncState *fs, int v, int l, const char *what) {
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97 if (v > l) errorlimit(fs, l, what);
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98 }
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99
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100
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101 static int testnext (LexState *ls, int c) {
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102 if (ls->t.token == c) {
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103 luaX_next(ls);
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104 return 1;
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105 }
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106 else return 0;
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107 }
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108
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109
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110 static void check (LexState *ls, int c) {
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111 if (ls->t.token != c)
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112 error_expected(ls, c);
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113 }
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114
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115
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116 static void checknext (LexState *ls, int c) {
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117 check(ls, c);
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118 luaX_next(ls);
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119 }
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120
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121
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122 #define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); }
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123
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124
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125
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126 static void check_match (LexState *ls, int what, int who, int where) {
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127 if (!testnext(ls, what)) {
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128 if (where == ls->linenumber)
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129 error_expected(ls, what);
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130 else {
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131 luaX_syntaxerror(ls, luaO_pushfstring(ls->L,
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132 "%s expected (to close %s at line %d)",
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133 luaX_token2str(ls, what), luaX_token2str(ls, who), where));
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134 }
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135 }
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136 }
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137
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138
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139 static TString *str_checkname (LexState *ls) {
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140 TString *ts;
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141 check(ls, TK_NAME);
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142 ts = ls->t.seminfo.ts;
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143 luaX_next(ls);
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144 return ts;
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145 }
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146
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147
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148 static void init_exp (expdesc *e, expkind k, int i) {
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149 e->f = e->t = NO_JUMP;
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150 e->k = k;
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151 e->u.info = i;
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152 }
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153
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154
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155 static void codestring (LexState *ls, expdesc *e, TString *s) {
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156 init_exp(e, VK, luaK_stringK(ls->fs, s));
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157 }
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158
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159
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160 static void checkname (LexState *ls, expdesc *e) {
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161 codestring(ls, e, str_checkname(ls));
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162 }
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163
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164
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165 static int registerlocalvar (LexState *ls, TString *varname) {
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166 FuncState *fs = ls->fs;
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167 Proto *f = fs->f;
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168 int oldsize = f->sizelocvars;
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169 luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars,
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170 LocVar, SHRT_MAX, "local variables");
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171 while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL;
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172 f->locvars[fs->nlocvars].varname = varname;
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173 luaC_objbarrier(ls->L, f, varname);
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174 return fs->nlocvars++;
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175 }
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176
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177
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178 static void new_localvar (LexState *ls, TString *name) {
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179 FuncState *fs = ls->fs;
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180 Dyndata *dyd = ls->dyd;
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181 int reg = registerlocalvar(ls, name);
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182 checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal,
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183 MAXVARS, "local variables");
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184 luaM_growvector(ls->L, dyd->actvar.arr, dyd->actvar.n + 1,
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185 dyd->actvar.size, Vardesc, MAX_INT, "local variables");
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186 dyd->actvar.arr[dyd->actvar.n++].idx = cast(short, reg);
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187 }
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188
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189
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190 static void new_localvarliteral_ (LexState *ls, const char *name, size_t sz) {
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191 new_localvar(ls, luaX_newstring(ls, name, sz));
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192 }
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193
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194 #define new_localvarliteral(ls,v) \
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195 new_localvarliteral_(ls, "" v, (sizeof(v)/sizeof(char))-1)
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196
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197
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198 static LocVar *getlocvar (FuncState *fs, int i) {
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199 int idx = fs->ls->dyd->actvar.arr[fs->firstlocal + i].idx;
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200 lua_assert(idx < fs->nlocvars);
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201 return &fs->f->locvars[idx];
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202 }
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203
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204
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205 static void adjustlocalvars (LexState *ls, int nvars) {
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206 FuncState *fs = ls->fs;
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207 fs->nactvar = cast_byte(fs->nactvar + nvars);
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208 for (; nvars; nvars--) {
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209 getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc;
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210 }
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211 }
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212
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213
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214 static void removevars (FuncState *fs, int tolevel) {
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215 fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel);
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216 while (fs->nactvar > tolevel)
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217 getlocvar(fs, --fs->nactvar)->endpc = fs->pc;
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218 }
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219
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220
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221 static int searchupvalue (FuncState *fs, TString *name) {
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222 int i;
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223 Upvaldesc *up = fs->f->upvalues;
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224 for (i = 0; i < fs->nups; i++) {
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225 if (luaS_eqstr(up[i].name, name)) return i;
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226 }
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227 return -1; /* not found */
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228 }
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229
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230
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231 static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
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232 Proto *f = fs->f;
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233 int oldsize = f->sizeupvalues;
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234 checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues");
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235 luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues,
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236 Upvaldesc, MAXUPVAL, "upvalues");
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237 while (oldsize < f->sizeupvalues) f->upvalues[oldsize++].name = NULL;
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238 f->upvalues[fs->nups].instack = (v->k == VLOCAL);
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239 f->upvalues[fs->nups].idx = cast_byte(v->u.info);
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240 f->upvalues[fs->nups].name = name;
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241 luaC_objbarrier(fs->ls->L, f, name);
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242 return fs->nups++;
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243 }
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244
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245
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246 static int searchvar (FuncState *fs, TString *n) {
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247 int i;
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248 for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) {
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249 if (luaS_eqstr(n, getlocvar(fs, i)->varname))
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250 return i;
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251 }
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252 return -1; /* not found */
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253 }
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254
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255
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256 /*
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257 Mark block where variable at given level was defined
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258 (to emit close instructions later).
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259 */
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260 static void markupval (FuncState *fs, int level) {
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261 BlockCnt *bl = fs->bl;
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262 while (bl->nactvar > level) bl = bl->previous;
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263 bl->upval = 1;
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264 }
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265
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266
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267 /*
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268 Find variable with given name 'n'. If it is an upvalue, add this
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269 upvalue into all intermediate functions.
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270 */
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271 static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
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272 if (fs == NULL) /* no more levels? */
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273 return VVOID; /* default is global */
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274 else {
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275 int v = searchvar(fs, n); /* look up locals at current level */
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276 if (v >= 0) { /* found? */
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277 init_exp(var, VLOCAL, v); /* variable is local */
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278 if (!base)
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279 markupval(fs, v); /* local will be used as an upval */
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280 return VLOCAL;
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281 }
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282 else { /* not found as local at current level; try upvalues */
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283 int idx = searchupvalue(fs, n); /* try existing upvalues */
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284 if (idx < 0) { /* not found? */
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285 if (singlevaraux(fs->prev, n, var, 0) == VVOID) /* try upper levels */
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286 return VVOID; /* not found; is a global */
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287 /* else was LOCAL or UPVAL */
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288 idx = newupvalue(fs, n, var); /* will be a new upvalue */
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289 }
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290 init_exp(var, VUPVAL, idx);
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291 return VUPVAL;
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292 }
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293 }
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294 }
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295
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296
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297 static void singlevar (LexState *ls, expdesc *var) {
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298 TString *varname = str_checkname(ls);
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299 FuncState *fs = ls->fs;
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300 if (singlevaraux(fs, varname, var, 1) == VVOID) { /* global name? */
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301 expdesc key;
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302 singlevaraux(fs, ls->envn, var, 1); /* get environment variable */
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303 lua_assert(var->k == VLOCAL || var->k == VUPVAL);
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304 codestring(ls, &key, varname); /* key is variable name */
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305 luaK_indexed(fs, var, &key); /* env[varname] */
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306 }
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307 }
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308
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309
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310 static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
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311 FuncState *fs = ls->fs;
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312 int extra = nvars - nexps;
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313 if (hasmultret(e->k)) {
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314 extra++; /* includes call itself */
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315 if (extra < 0) extra = 0;
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316 luaK_setreturns(fs, e, extra); /* last exp. provides the difference */
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317 if (extra > 1) luaK_reserveregs(fs, extra-1);
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318 }
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319 else {
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320 if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */
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321 if (extra > 0) {
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322 int reg = fs->freereg;
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323 luaK_reserveregs(fs, extra);
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324 luaK_nil(fs, reg, extra);
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325 }
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326 }
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327 }
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328
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329
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330 static void enterlevel (LexState *ls) {
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331 lua_State *L = ls->L;
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332 ++L->nCcalls;
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333 checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels");
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334 }
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335
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336
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337 #define leavelevel(ls) ((ls)->L->nCcalls--)
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338
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339
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340 static void closegoto (LexState *ls, int g, Labeldesc *label) {
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341 int i;
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342 FuncState *fs = ls->fs;
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343 Labellist *gl = &ls->dyd->gt;
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344 Labeldesc *gt = &gl->arr[g];
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345 lua_assert(luaS_eqstr(gt->name, label->name));
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346 if (gt->nactvar < label->nactvar) {
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347 TString *vname = getlocvar(fs, gt->nactvar)->varname;
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348 const char *msg = luaO_pushfstring(ls->L,
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349 "<goto %s> at line %d jumps into the scope of local " LUA_QS,
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350 getstr(gt->name), gt->line, getstr(vname));
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351 semerror(ls, msg);
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352 }
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353 luaK_patchlist(fs, gt->pc, label->pc);
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354 /* remove goto from pending list */
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355 for (i = g; i < gl->n - 1; i++)
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356 gl->arr[i] = gl->arr[i + 1];
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357 gl->n--;
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358 }
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359
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360
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361 /*
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362 ** try to close a goto with existing labels; this solves backward jumps
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363 */
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364 static int findlabel (LexState *ls, int g) {
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365 int i;
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366 BlockCnt *bl = ls->fs->bl;
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367 Dyndata *dyd = ls->dyd;
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368 Labeldesc *gt = &dyd->gt.arr[g];
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369 /* check labels in current block for a match */
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370 for (i = bl->firstlabel; i < dyd->label.n; i++) {
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371 Labeldesc *lb = &dyd->label.arr[i];
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372 if (luaS_eqstr(lb->name, gt->name)) { /* correct label? */
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373 if (gt->nactvar > lb->nactvar &&
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374 (bl->upval || dyd->label.n > bl->firstlabel))
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375 luaK_patchclose(ls->fs, gt->pc, lb->nactvar);
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376 closegoto(ls, g, lb); /* close it */
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377 return 1;
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378 }
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379 }
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380 return 0; /* label not found; cannot close goto */
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381 }
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382
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383
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384 static int newlabelentry (LexState *ls, Labellist *l, TString *name,
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385 int line, int pc) {
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386 int n = l->n;
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387 luaM_growvector(ls->L, l->arr, n, l->size,
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388 Labeldesc, SHRT_MAX, "labels/gotos");
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389 l->arr[n].name = name;
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390 l->arr[n].line = line;
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391 l->arr[n].nactvar = ls->fs->nactvar;
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392 l->arr[n].pc = pc;
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393 l->n++;
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394 return n;
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|
395 }
|
|
|
396
|
|
|
397
|
|
|
398 /*
|
|
|
399 ** check whether new label 'lb' matches any pending gotos in current
|
|
|
400 ** block; solves forward jumps
|
|
|
401 */
|
|
|
402 static void findgotos (LexState *ls, Labeldesc *lb) {
|
|
|
403 Labellist *gl = &ls->dyd->gt;
|
|
|
404 int i = ls->fs->bl->firstgoto;
|
|
|
405 while (i < gl->n) {
|
|
|
406 if (luaS_eqstr(gl->arr[i].name, lb->name))
|
|
|
407 closegoto(ls, i, lb);
|
|
|
408 else
|
|
|
409 i++;
|
|
|
410 }
|
|
|
411 }
|
|
|
412
|
|
|
413
|
|
|
414 /*
|
|
|
415 ** "export" pending gotos to outer level, to check them against
|
|
|
416 ** outer labels; if the block being exited has upvalues, and
|
|
|
417 ** the goto exits the scope of any variable (which can be the
|
|
|
418 ** upvalue), close those variables being exited.
|
|
|
419 */
|
|
|
420 static void movegotosout (FuncState *fs, BlockCnt *bl) {
|
|
|
421 int i = bl->firstgoto;
|
|
|
422 Labellist *gl = &fs->ls->dyd->gt;
|
|
|
423 /* correct pending gotos to current block and try to close it
|
|
|
424 with visible labels */
|
|
|
425 while (i < gl->n) {
|
|
|
426 Labeldesc *gt = &gl->arr[i];
|
|
|
427 if (gt->nactvar > bl->nactvar) {
|
|
|
428 if (bl->upval)
|
|
|
429 luaK_patchclose(fs, gt->pc, bl->nactvar);
|
|
|
430 gt->nactvar = bl->nactvar;
|
|
|
431 }
|
|
|
432 if (!findlabel(fs->ls, i))
|
|
|
433 i++; /* move to next one */
|
|
|
434 }
|
|
|
435 }
|
|
|
436
|
|
|
437
|
|
|
438 static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) {
|
|
|
439 bl->isloop = isloop;
|
|
|
440 bl->nactvar = fs->nactvar;
|
|
|
441 bl->firstlabel = fs->ls->dyd->label.n;
|
|
|
442 bl->firstgoto = fs->ls->dyd->gt.n;
|
|
|
443 bl->upval = 0;
|
|
|
444 bl->previous = fs->bl;
|
|
|
445 fs->bl = bl;
|
|
|
446 lua_assert(fs->freereg == fs->nactvar);
|
|
|
447 }
|
|
|
448
|
|
|
449
|
|
|
450 /*
|
|
|
451 ** create a label named "break" to resolve break statements
|
|
|
452 */
|
|
|
453 static void breaklabel (LexState *ls) {
|
|
|
454 TString *n = luaS_new(ls->L, "break");
|
|
|
455 int l = newlabelentry(ls, &ls->dyd->label, n, 0, ls->fs->pc);
|
|
|
456 findgotos(ls, &ls->dyd->label.arr[l]);
|
|
|
457 }
|
|
|
458
|
|
|
459 /*
|
|
|
460 ** generates an error for an undefined 'goto'; choose appropriate
|
|
|
461 ** message when label name is a reserved word (which can only be 'break')
|
|
|
462 */
|
|
|
463 static l_noret undefgoto (LexState *ls, Labeldesc *gt) {
|
|
|
464 const char *msg = isreserved(gt->name)
|
|
|
465 ? "<%s> at line %d not inside a loop"
|
|
|
466 : "no visible label " LUA_QS " for <goto> at line %d";
|
|
|
467 msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line);
|
|
|
468 semerror(ls, msg);
|
|
|
469 }
|
|
|
470
|
|
|
471
|
|
|
472 static void leaveblock (FuncState *fs) {
|
|
|
473 BlockCnt *bl = fs->bl;
|
|
|
474 LexState *ls = fs->ls;
|
|
|
475 if (bl->previous && bl->upval) {
|
|
|
476 /* create a 'jump to here' to close upvalues */
|
|
|
477 int j = luaK_jump(fs);
|
|
|
478 luaK_patchclose(fs, j, bl->nactvar);
|
|
|
479 luaK_patchtohere(fs, j);
|
|
|
480 }
|
|
|
481 if (bl->isloop)
|
|
|
482 breaklabel(ls); /* close pending breaks */
|
|
|
483 fs->bl = bl->previous;
|
|
|
484 removevars(fs, bl->nactvar);
|
|
|
485 lua_assert(bl->nactvar == fs->nactvar);
|
|
|
486 fs->freereg = fs->nactvar; /* free registers */
|
|
|
487 ls->dyd->label.n = bl->firstlabel; /* remove local labels */
|
|
|
488 if (bl->previous) /* inner block? */
|
|
|
489 movegotosout(fs, bl); /* update pending gotos to outer block */
|
|
|
490 else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */
|
|
|
491 undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */
|
|
|
492 }
|
|
|
493
|
|
|
494
|
|
|
495 /*
|
|
|
496 ** adds a new prototype into list of prototypes
|
|
|
497 */
|
|
|
498 static Proto *addprototype (LexState *ls) {
|
|
|
499 Proto *clp;
|
|
|
500 lua_State *L = ls->L;
|
|
|
501 FuncState *fs = ls->fs;
|
|
|
502 Proto *f = fs->f; /* prototype of current function */
|
|
|
503 if (fs->np >= f->sizep) {
|
|
|
504 int oldsize = f->sizep;
|
|
|
505 luaM_growvector(L, f->p, fs->np, f->sizep, Proto *, MAXARG_Bx, "functions");
|
|
|
506 while (oldsize < f->sizep) f->p[oldsize++] = NULL;
|
|
|
507 }
|
|
|
508 f->p[fs->np++] = clp = luaF_newproto(L);
|
|
|
509 luaC_objbarrier(L, f, clp);
|
|
|
510 return clp;
|
|
|
511 }
|
|
|
512
|
|
|
513
|
|
|
514 /*
|
|
|
515 ** codes instruction to create new closure in parent function.
|
|
|
516 ** The OP_CLOSURE instruction must use the last available register,
|
|
|
517 ** so that, if it invokes the GC, the GC knows which registers
|
|
|
518 ** are in use at that time.
|
|
|
519 */
|
|
|
520 static void codeclosure (LexState *ls, expdesc *v) {
|
|
|
521 FuncState *fs = ls->fs->prev;
|
|
|
522 init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1));
|
|
|
523 luaK_exp2nextreg(fs, v); /* fix it at the last register */
|
|
|
524 }
|
|
|
525
|
|
|
526
|
|
|
527 static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) {
|
|
|
528 lua_State *L = ls->L;
|
|
|
529 Proto *f;
|
|
|
530 fs->prev = ls->fs; /* linked list of funcstates */
|
|
|
531 fs->ls = ls;
|
|
|
532 ls->fs = fs;
|
|
|
533 fs->pc = 0;
|
|
|
534 fs->lasttarget = 0;
|
|
|
535 fs->jpc = NO_JUMP;
|
|
|
536 fs->freereg = 0;
|
|
|
537 fs->nk = 0;
|
|
|
538 fs->np = 0;
|
|
|
539 fs->nups = 0;
|
|
|
540 fs->nlocvars = 0;
|
|
|
541 fs->nactvar = 0;
|
|
|
542 fs->firstlocal = ls->dyd->actvar.n;
|
|
|
543 fs->bl = NULL;
|
|
|
544 f = fs->f;
|
|
|
545 f->source = ls->source;
|
|
|
546 f->maxstacksize = 2; /* registers 0/1 are always valid */
|
|
|
547 fs->h = luaH_new(L);
|
|
|
548 /* anchor table of constants (to avoid being collected) */
|
|
|
549 sethvalue2s(L, L->top, fs->h);
|
|
|
550 incr_top(L);
|
|
|
551 enterblock(fs, bl, 0);
|
|
|
552 }
|
|
|
553
|
|
|
554
|
|
|
555 static void close_func (LexState *ls) {
|
|
|
556 lua_State *L = ls->L;
|
|
|
557 FuncState *fs = ls->fs;
|
|
|
558 Proto *f = fs->f;
|
|
|
559 luaK_ret(fs, 0, 0); /* final return */
|
|
|
560 leaveblock(fs);
|
|
|
561 luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
|
|
|
562 f->sizecode = fs->pc;
|
|
|
563 luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
|
|
|
564 f->sizelineinfo = fs->pc;
|
|
|
565 luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue);
|
|
|
566 f->sizek = fs->nk;
|
|
|
567 luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *);
|
|
|
568 f->sizep = fs->np;
|
|
|
569 luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar);
|
|
|
570 f->sizelocvars = fs->nlocvars;
|
|
|
571 luaM_reallocvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc);
|
|
|
572 f->sizeupvalues = fs->nups;
|
|
|
573 lua_assert(fs->bl == NULL);
|
|
|
574 ls->fs = fs->prev;
|
|
|
575 /* last token read was anchored in defunct function; must re-anchor it */
|
|
|
576 anchor_token(ls);
|
|
|
577 L->top--; /* pop table of constants */
|
|
|
578 luaC_checkGC(L);
|
|
|
579 }
|
|
|
580
|
|
|
581
|
|
|
582
|
|
|
583 /*============================================================*/
|
|
|
584 /* GRAMMAR RULES */
|
|
|
585 /*============================================================*/
|
|
|
586
|
|
|
587
|
|
|
588 /*
|
|
|
589 ** check whether current token is in the follow set of a block.
|
|
|
590 ** 'until' closes syntactical blocks, but do not close scope,
|
|
|
591 ** so it handled in separate.
|
|
|
592 */
|
|
|
593 static int block_follow (LexState *ls, int withuntil) {
|
|
|
594 switch (ls->t.token) {
|
|
|
595 case TK_ELSE: case TK_ELSEIF:
|
|
|
596 case TK_END: case TK_EOS:
|
|
|
597 return 1;
|
|
|
598 case TK_UNTIL: return withuntil;
|
|
|
599 default: return 0;
|
|
|
600 }
|
|
|
601 }
|
|
|
602
|
|
|
603
|
|
|
604 static void statlist (LexState *ls) {
|
|
|
605 /* statlist -> { stat [`;'] } */
|
|
|
606 while (!block_follow(ls, 1)) {
|
|
|
607 if (ls->t.token == TK_RETURN) {
|
|
|
608 statement(ls);
|
|
|
609 return; /* 'return' must be last statement */
|
|
|
610 }
|
|
|
611 statement(ls);
|
|
|
612 }
|
|
|
613 }
|
|
|
614
|
|
|
615
|
|
|
616 static void fieldsel (LexState *ls, expdesc *v) {
|
|
|
617 /* fieldsel -> ['.' | ':'] NAME */
|
|
|
618 FuncState *fs = ls->fs;
|
|
|
619 expdesc key;
|
|
|
620 luaK_exp2anyregup(fs, v);
|
|
|
621 luaX_next(ls); /* skip the dot or colon */
|
|
|
622 checkname(ls, &key);
|
|
|
623 luaK_indexed(fs, v, &key);
|
|
|
624 }
|
|
|
625
|
|
|
626
|
|
|
627 static void yindex (LexState *ls, expdesc *v) {
|
|
|
628 /* index -> '[' expr ']' */
|
|
|
629 luaX_next(ls); /* skip the '[' */
|
|
|
630 expr(ls, v);
|
|
|
631 luaK_exp2val(ls->fs, v);
|
|
|
632 checknext(ls, ']');
|
|
|
633 }
|
|
|
634
|
|
|
635
|
|
|
636 /*
|
|
|
637 ** {======================================================================
|
|
|
638 ** Rules for Constructors
|
|
|
639 ** =======================================================================
|
|
|
640 */
|
|
|
641
|
|
|
642
|
|
|
643 struct ConsControl {
|
|
|
644 expdesc v; /* last list item read */
|
|
|
645 expdesc *t; /* table descriptor */
|
|
|
646 int nh; /* total number of `record' elements */
|
|
|
647 int na; /* total number of array elements */
|
|
|
648 int tostore; /* number of array elements pending to be stored */
|
|
|
649 };
|
|
|
650
|
|
|
651
|
|
|
652 static void recfield (LexState *ls, struct ConsControl *cc) {
|
|
|
653 /* recfield -> (NAME | `['exp1`]') = exp1 */
|
|
|
654 FuncState *fs = ls->fs;
|
|
|
655 int reg = ls->fs->freereg;
|
|
|
656 expdesc key, val;
|
|
|
657 int rkkey;
|
|
|
658 if (ls->t.token == TK_NAME) {
|
|
|
659 checklimit(fs, cc->nh, MAX_INT, "items in a constructor");
|
|
|
660 checkname(ls, &key);
|
|
|
661 }
|
|
|
662 else /* ls->t.token == '[' */
|
|
|
663 yindex(ls, &key);
|
|
|
664 cc->nh++;
|
|
|
665 checknext(ls, '=');
|
|
|
666 rkkey = luaK_exp2RK(fs, &key);
|
|
|
667 expr(ls, &val);
|
|
|
668 luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val));
|
|
|
669 fs->freereg = reg; /* free registers */
|
|
|
670 }
|
|
|
671
|
|
|
672
|
|
|
673 static void closelistfield (FuncState *fs, struct ConsControl *cc) {
|
|
|
674 if (cc->v.k == VVOID) return; /* there is no list item */
|
|
|
675 luaK_exp2nextreg(fs, &cc->v);
|
|
|
676 cc->v.k = VVOID;
|
|
|
677 if (cc->tostore == LFIELDS_PER_FLUSH) {
|
|
|
678 luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); /* flush */
|
|
|
679 cc->tostore = 0; /* no more items pending */
|
|
|
680 }
|
|
|
681 }
|
|
|
682
|
|
|
683
|
|
|
684 static void lastlistfield (FuncState *fs, struct ConsControl *cc) {
|
|
|
685 if (cc->tostore == 0) return;
|
|
|
686 if (hasmultret(cc->v.k)) {
|
|
|
687 luaK_setmultret(fs, &cc->v);
|
|
|
688 luaK_setlist(fs, cc->t->u.info, cc->na, LUA_MULTRET);
|
|
|
689 cc->na--; /* do not count last expression (unknown number of elements) */
|
|
|
690 }
|
|
|
691 else {
|
|
|
692 if (cc->v.k != VVOID)
|
|
|
693 luaK_exp2nextreg(fs, &cc->v);
|
|
|
694 luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore);
|
|
|
695 }
|
|
|
696 }
|
|
|
697
|
|
|
698
|
|
|
699 static void listfield (LexState *ls, struct ConsControl *cc) {
|
|
|
700 /* listfield -> exp */
|
|
|
701 expr(ls, &cc->v);
|
|
|
702 checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor");
|
|
|
703 cc->na++;
|
|
|
704 cc->tostore++;
|
|
|
705 }
|
|
|
706
|
|
|
707
|
|
|
708 static void field (LexState *ls, struct ConsControl *cc) {
|
|
|
709 /* field -> listfield | recfield */
|
|
|
710 switch(ls->t.token) {
|
|
|
711 case TK_NAME: { /* may be 'listfield' or 'recfield' */
|
|
|
712 if (luaX_lookahead(ls) != '=') /* expression? */
|
|
|
713 listfield(ls, cc);
|
|
|
714 else
|
|
|
715 recfield(ls, cc);
|
|
|
716 break;
|
|
|
717 }
|
|
|
718 case '[': {
|
|
|
719 recfield(ls, cc);
|
|
|
720 break;
|
|
|
721 }
|
|
|
722 default: {
|
|
|
723 listfield(ls, cc);
|
|
|
724 break;
|
|
|
725 }
|
|
|
726 }
|
|
|
727 }
|
|
|
728
|
|
|
729
|
|
|
730 static void constructor (LexState *ls, expdesc *t) {
|
|
|
731 /* constructor -> '{' [ field { sep field } [sep] ] '}'
|
|
|
732 sep -> ',' | ';' */
|
|
|
733 FuncState *fs = ls->fs;
|
|
|
734 int line = ls->linenumber;
|
|
|
735 int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0);
|
|
|
736 struct ConsControl cc;
|
|
|
737 cc.na = cc.nh = cc.tostore = 0;
|
|
|
738 cc.t = t;
|
|
|
739 init_exp(t, VRELOCABLE, pc);
|
|
|
740 init_exp(&cc.v, VVOID, 0); /* no value (yet) */
|
|
|
741 luaK_exp2nextreg(ls->fs, t); /* fix it at stack top */
|
|
|
742 checknext(ls, '{');
|
|
|
743 do {
|
|
|
744 lua_assert(cc.v.k == VVOID || cc.tostore > 0);
|
|
|
745 if (ls->t.token == '}') break;
|
|
|
746 closelistfield(fs, &cc);
|
|
|
747 field(ls, &cc);
|
|
|
748 } while (testnext(ls, ',') || testnext(ls, ';'));
|
|
|
749 check_match(ls, '}', '{', line);
|
|
|
750 lastlistfield(fs, &cc);
|
|
|
751 SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */
|
|
|
752 SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh)); /* set initial table size */
|
|
|
753 }
|
|
|
754
|
|
|
755 /* }====================================================================== */
|
|
|
756
|
|
|
757
|
|
|
758
|
|
|
759 static void parlist (LexState *ls) {
|
|
|
760 /* parlist -> [ param { `,' param } ] */
|
|
|
761 FuncState *fs = ls->fs;
|
|
|
762 Proto *f = fs->f;
|
|
|
763 int nparams = 0;
|
|
|
764 f->is_vararg = 0;
|
|
|
765 if (ls->t.token != ')') { /* is `parlist' not empty? */
|
|
|
766 do {
|
|
|
767 switch (ls->t.token) {
|
|
|
768 case TK_NAME: { /* param -> NAME */
|
|
|
769 new_localvar(ls, str_checkname(ls));
|
|
|
770 nparams++;
|
|
|
771 break;
|
|
|
772 }
|
|
|
773 case TK_DOTS: { /* param -> `...' */
|
|
|
774 luaX_next(ls);
|
|
|
775 f->is_vararg = 1;
|
|
|
776 break;
|
|
|
777 }
|
|
|
778 default: luaX_syntaxerror(ls, "<name> or " LUA_QL("...") " expected");
|
|
|
779 }
|
|
|
780 } while (!f->is_vararg && testnext(ls, ','));
|
|
|
781 }
|
|
|
782 adjustlocalvars(ls, nparams);
|
|
|
783 f->numparams = cast_byte(fs->nactvar);
|
|
|
784 luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */
|
|
|
785 }
|
|
|
786
|
|
|
787
|
|
|
788 static void body (LexState *ls, expdesc *e, int ismethod, int line) {
|
|
|
789 /* body -> `(' parlist `)' block END */
|
|
|
790 FuncState new_fs;
|
|
|
791 BlockCnt bl;
|
|
|
792 new_fs.f = addprototype(ls);
|
|
|
793 new_fs.f->linedefined = line;
|
|
|
794 open_func(ls, &new_fs, &bl);
|
|
|
795 checknext(ls, '(');
|
|
|
796 if (ismethod) {
|
|
|
797 new_localvarliteral(ls, "self"); /* create 'self' parameter */
|
|
|
798 adjustlocalvars(ls, 1);
|
|
|
799 }
|
|
|
800 parlist(ls);
|
|
|
801 checknext(ls, ')');
|
|
|
802 statlist(ls);
|
|
|
803 new_fs.f->lastlinedefined = ls->linenumber;
|
|
|
804 check_match(ls, TK_END, TK_FUNCTION, line);
|
|
|
805 codeclosure(ls, e);
|
|
|
806 close_func(ls);
|
|
|
807 }
|
|
|
808
|
|
|
809
|
|
|
810 static int explist (LexState *ls, expdesc *v) {
|
|
|
811 /* explist -> expr { `,' expr } */
|
|
|
812 int n = 1; /* at least one expression */
|
|
|
813 expr(ls, v);
|
|
|
814 while (testnext(ls, ',')) {
|
|
|
815 luaK_exp2nextreg(ls->fs, v);
|
|
|
816 expr(ls, v);
|
|
|
817 n++;
|
|
|
818 }
|
|
|
819 return n;
|
|
|
820 }
|
|
|
821
|
|
|
822
|
|
|
823 static void funcargs (LexState *ls, expdesc *f, int line) {
|
|
|
824 FuncState *fs = ls->fs;
|
|
|
825 expdesc args;
|
|
|
826 int base, nparams;
|
|
|
827 switch (ls->t.token) {
|
|
|
828 case '(': { /* funcargs -> `(' [ explist ] `)' */
|
|
|
829 luaX_next(ls);
|
|
|
830 if (ls->t.token == ')') /* arg list is empty? */
|
|
|
831 args.k = VVOID;
|
|
|
832 else {
|
|
|
833 explist(ls, &args);
|
|
|
834 luaK_setmultret(fs, &args);
|
|
|
835 }
|
|
|
836 check_match(ls, ')', '(', line);
|
|
|
837 break;
|
|
|
838 }
|
|
|
839 case '{': { /* funcargs -> constructor */
|
|
|
840 constructor(ls, &args);
|
|
|
841 break;
|
|
|
842 }
|
|
|
843 case TK_STRING: { /* funcargs -> STRING */
|
|
|
844 codestring(ls, &args, ls->t.seminfo.ts);
|
|
|
845 luaX_next(ls); /* must use `seminfo' before `next' */
|
|
|
846 break;
|
|
|
847 }
|
|
|
848 default: {
|
|
|
849 luaX_syntaxerror(ls, "function arguments expected");
|
|
|
850 }
|
|
|
851 }
|
|
|
852 lua_assert(f->k == VNONRELOC);
|
|
|
853 base = f->u.info; /* base register for call */
|
|
|
854 if (hasmultret(args.k))
|
|
|
855 nparams = LUA_MULTRET; /* open call */
|
|
|
856 else {
|
|
|
857 if (args.k != VVOID)
|
|
|
858 luaK_exp2nextreg(fs, &args); /* close last argument */
|
|
|
859 nparams = fs->freereg - (base+1);
|
|
|
860 }
|
|
|
861 init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2));
|
|
|
862 luaK_fixline(fs, line);
|
|
|
863 fs->freereg = base+1; /* call remove function and arguments and leaves
|
|
|
864 (unless changed) one result */
|
|
|
865 }
|
|
|
866
|
|
|
867
|
|
|
868
|
|
|
869
|
|
|
870 /*
|
|
|
871 ** {======================================================================
|
|
|
872 ** Expression parsing
|
|
|
873 ** =======================================================================
|
|
|
874 */
|
|
|
875
|
|
|
876
|
|
|
877 static void primaryexp (LexState *ls, expdesc *v) {
|
|
|
878 /* primaryexp -> NAME | '(' expr ')' */
|
|
|
879 switch (ls->t.token) {
|
|
|
880 case '(': {
|
|
|
881 int line = ls->linenumber;
|
|
|
882 luaX_next(ls);
|
|
|
883 expr(ls, v);
|
|
|
884 check_match(ls, ')', '(', line);
|
|
|
885 luaK_dischargevars(ls->fs, v);
|
|
|
886 return;
|
|
|
887 }
|
|
|
888 case TK_NAME: {
|
|
|
889 singlevar(ls, v);
|
|
|
890 return;
|
|
|
891 }
|
|
|
892 default: {
|
|
|
893 luaX_syntaxerror(ls, "unexpected symbol");
|
|
|
894 }
|
|
|
895 }
|
|
|
896 }
|
|
|
897
|
|
|
898
|
|
|
899 static void suffixedexp (LexState *ls, expdesc *v) {
|
|
|
900 /* suffixedexp ->
|
|
|
901 primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */
|
|
|
902 FuncState *fs = ls->fs;
|
|
|
903 int line = ls->linenumber;
|
|
|
904 primaryexp(ls, v);
|
|
|
905 for (;;) {
|
|
|
906 switch (ls->t.token) {
|
|
|
907 case '.': { /* fieldsel */
|
|
|
908 fieldsel(ls, v);
|
|
|
909 break;
|
|
|
910 }
|
|
|
911 case '[': { /* `[' exp1 `]' */
|
|
|
912 expdesc key;
|
|
|
913 luaK_exp2anyregup(fs, v);
|
|
|
914 yindex(ls, &key);
|
|
|
915 luaK_indexed(fs, v, &key);
|
|
|
916 break;
|
|
|
917 }
|
|
|
918 case ':': { /* `:' NAME funcargs */
|
|
|
919 expdesc key;
|
|
|
920 luaX_next(ls);
|
|
|
921 checkname(ls, &key);
|
|
|
922 luaK_self(fs, v, &key);
|
|
|
923 funcargs(ls, v, line);
|
|
|
924 break;
|
|
|
925 }
|
|
|
926 case '(': case TK_STRING: case '{': { /* funcargs */
|
|
|
927 luaK_exp2nextreg(fs, v);
|
|
|
928 funcargs(ls, v, line);
|
|
|
929 break;
|
|
|
930 }
|
|
|
931 default: return;
|
|
|
932 }
|
|
|
933 }
|
|
|
934 }
|
|
|
935
|
|
|
936
|
|
|
937 static void simpleexp (LexState *ls, expdesc *v) {
|
|
|
938 /* simpleexp -> NUMBER | STRING | NIL | TRUE | FALSE | ... |
|
|
|
939 constructor | FUNCTION body | suffixedexp */
|
|
|
940 switch (ls->t.token) {
|
|
|
941 case TK_NUMBER: {
|
|
|
942 init_exp(v, VKNUM, 0);
|
|
|
943 v->u.nval = ls->t.seminfo.r;
|
|
|
944 break;
|
|
|
945 }
|
|
|
946 case TK_STRING: {
|
|
|
947 codestring(ls, v, ls->t.seminfo.ts);
|
|
|
948 break;
|
|
|
949 }
|
|
|
950 case TK_NIL: {
|
|
|
951 init_exp(v, VNIL, 0);
|
|
|
952 break;
|
|
|
953 }
|
|
|
954 case TK_TRUE: {
|
|
|
955 init_exp(v, VTRUE, 0);
|
|
|
956 break;
|
|
|
957 }
|
|
|
958 case TK_FALSE: {
|
|
|
959 init_exp(v, VFALSE, 0);
|
|
|
960 break;
|
|
|
961 }
|
|
|
962 case TK_DOTS: { /* vararg */
|
|
|
963 FuncState *fs = ls->fs;
|
|
|
964 check_condition(ls, fs->f->is_vararg,
|
|
|
965 "cannot use " LUA_QL("...") " outside a vararg function");
|
|
|
966 init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0));
|
|
|
967 break;
|
|
|
968 }
|
|
|
969 case '{': { /* constructor */
|
|
|
970 constructor(ls, v);
|
|
|
971 return;
|
|
|
972 }
|
|
|
973 case TK_FUNCTION: {
|
|
|
974 luaX_next(ls);
|
|
|
975 body(ls, v, 0, ls->linenumber);
|
|
|
976 return;
|
|
|
977 }
|
|
|
978 default: {
|
|
|
979 suffixedexp(ls, v);
|
|
|
980 return;
|
|
|
981 }
|
|
|
982 }
|
|
|
983 luaX_next(ls);
|
|
|
984 }
|
|
|
985
|
|
|
986
|
|
|
987 static UnOpr getunopr (int op) {
|
|
|
988 switch (op) {
|
|
|
989 case TK_NOT: return OPR_NOT;
|
|
|
990 case '-': return OPR_MINUS;
|
|
|
991 case '#': return OPR_LEN;
|
|
|
992 default: return OPR_NOUNOPR;
|
|
|
993 }
|
|
|
994 }
|
|
|
995
|
|
|
996
|
|
|
997 static BinOpr getbinopr (int op) {
|
|
|
998 switch (op) {
|
|
|
999 case '+': return OPR_ADD;
|
|
|
1000 case '-': return OPR_SUB;
|
|
|
1001 case '*': return OPR_MUL;
|
|
|
1002 case '/': return OPR_DIV;
|
|
|
1003 case '%': return OPR_MOD;
|
|
|
1004 case '^': return OPR_POW;
|
|
|
1005 case TK_CONCAT: return OPR_CONCAT;
|
|
|
1006 case TK_NE: return OPR_NE;
|
|
|
1007 case TK_EQ: return OPR_EQ;
|
|
|
1008 case '<': return OPR_LT;
|
|
|
1009 case TK_LE: return OPR_LE;
|
|
|
1010 case '>': return OPR_GT;
|
|
|
1011 case TK_GE: return OPR_GE;
|
|
|
1012 case TK_AND: return OPR_AND;
|
|
|
1013 case TK_OR: return OPR_OR;
|
|
|
1014 default: return OPR_NOBINOPR;
|
|
|
1015 }
|
|
|
1016 }
|
|
|
1017
|
|
|
1018
|
|
|
1019 static const struct {
|
|
|
1020 lu_byte left; /* left priority for each binary operator */
|
|
|
1021 lu_byte right; /* right priority */
|
|
|
1022 } priority[] = { /* ORDER OPR */
|
|
|
1023 {6, 6}, {6, 6}, {7, 7}, {7, 7}, {7, 7}, /* `+' `-' `*' `/' `%' */
|
|
|
1024 {10, 9}, {5, 4}, /* ^, .. (right associative) */
|
|
|
1025 {3, 3}, {3, 3}, {3, 3}, /* ==, <, <= */
|
|
|
1026 {3, 3}, {3, 3}, {3, 3}, /* ~=, >, >= */
|
|
|
1027 {2, 2}, {1, 1} /* and, or */
|
|
|
1028 };
|
|
|
1029
|
|
|
1030 #define UNARY_PRIORITY 8 /* priority for unary operators */
|
|
|
1031
|
|
|
1032
|
|
|
1033 /*
|
|
|
1034 ** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
|
|
|
1035 ** where `binop' is any binary operator with a priority higher than `limit'
|
|
|
1036 */
|
|
|
1037 static BinOpr subexpr (LexState *ls, expdesc *v, int limit) {
|
|
|
1038 BinOpr op;
|
|
|
1039 UnOpr uop;
|
|
|
1040 enterlevel(ls);
|
|
|
1041 uop = getunopr(ls->t.token);
|
|
|
1042 if (uop != OPR_NOUNOPR) {
|
|
|
1043 int line = ls->linenumber;
|
|
|
1044 luaX_next(ls);
|
|
|
1045 subexpr(ls, v, UNARY_PRIORITY);
|
|
|
1046 luaK_prefix(ls->fs, uop, v, line);
|
|
|
1047 }
|
|
|
1048 else simpleexp(ls, v);
|
|
|
1049 /* expand while operators have priorities higher than `limit' */
|
|
|
1050 op = getbinopr(ls->t.token);
|
|
|
1051 while (op != OPR_NOBINOPR && priority[op].left > limit) {
|
|
|
1052 expdesc v2;
|
|
|
1053 BinOpr nextop;
|
|
|
1054 int line = ls->linenumber;
|
|
|
1055 luaX_next(ls);
|
|
|
1056 luaK_infix(ls->fs, op, v);
|
|
|
1057 /* read sub-expression with higher priority */
|
|
|
1058 nextop = subexpr(ls, &v2, priority[op].right);
|
|
|
1059 luaK_posfix(ls->fs, op, v, &v2, line);
|
|
|
1060 op = nextop;
|
|
|
1061 }
|
|
|
1062 leavelevel(ls);
|
|
|
1063 return op; /* return first untreated operator */
|
|
|
1064 }
|
|
|
1065
|
|
|
1066
|
|
|
1067 static void expr (LexState *ls, expdesc *v) {
|
|
|
1068 subexpr(ls, v, 0);
|
|
|
1069 }
|
|
|
1070
|
|
|
1071 /* }==================================================================== */
|
|
|
1072
|
|
|
1073
|
|
|
1074
|
|
|
1075 /*
|
|
|
1076 ** {======================================================================
|
|
|
1077 ** Rules for Statements
|
|
|
1078 ** =======================================================================
|
|
|
1079 */
|
|
|
1080
|
|
|
1081
|
|
|
1082 static void block (LexState *ls) {
|
|
|
1083 /* block -> statlist */
|
|
|
1084 FuncState *fs = ls->fs;
|
|
|
1085 BlockCnt bl;
|
|
|
1086 enterblock(fs, &bl, 0);
|
|
|
1087 statlist(ls);
|
|
|
1088 leaveblock(fs);
|
|
|
1089 }
|
|
|
1090
|
|
|
1091
|
|
|
1092 /*
|
|
|
1093 ** structure to chain all variables in the left-hand side of an
|
|
|
1094 ** assignment
|
|
|
1095 */
|
|
|
1096 struct LHS_assign {
|
|
|
1097 struct LHS_assign *prev;
|
|
|
1098 expdesc v; /* variable (global, local, upvalue, or indexed) */
|
|
|
1099 };
|
|
|
1100
|
|
|
1101
|
|
|
1102 /*
|
|
|
1103 ** check whether, in an assignment to an upvalue/local variable, the
|
|
|
1104 ** upvalue/local variable is begin used in a previous assignment to a
|
|
|
1105 ** table. If so, save original upvalue/local value in a safe place and
|
|
|
1106 ** use this safe copy in the previous assignment.
|
|
|
1107 */
|
|
|
1108 static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) {
|
|
|
1109 FuncState *fs = ls->fs;
|
|
|
1110 int extra = fs->freereg; /* eventual position to save local variable */
|
|
|
1111 int conflict = 0;
|
|
|
1112 for (; lh; lh = lh->prev) { /* check all previous assignments */
|
|
|
1113 if (lh->v.k == VINDEXED) { /* assigning to a table? */
|
|
|
1114 /* table is the upvalue/local being assigned now? */
|
|
|
1115 if (lh->v.u.ind.vt == v->k && lh->v.u.ind.t == v->u.info) {
|
|
|
1116 conflict = 1;
|
|
|
1117 lh->v.u.ind.vt = VLOCAL;
|
|
|
1118 lh->v.u.ind.t = extra; /* previous assignment will use safe copy */
|
|
|
1119 }
|
|
|
1120 /* index is the local being assigned? (index cannot be upvalue) */
|
|
|
1121 if (v->k == VLOCAL && lh->v.u.ind.idx == v->u.info) {
|
|
|
1122 conflict = 1;
|
|
|
1123 lh->v.u.ind.idx = extra; /* previous assignment will use safe copy */
|
|
|
1124 }
|
|
|
1125 }
|
|
|
1126 }
|
|
|
1127 if (conflict) {
|
|
|
1128 /* copy upvalue/local value to a temporary (in position 'extra') */
|
|
|
1129 OpCode op = (v->k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
|
|
|
1130 luaK_codeABC(fs, op, extra, v->u.info, 0);
|
|
|
1131 luaK_reserveregs(fs, 1);
|
|
|
1132 }
|
|
|
1133 }
|
|
|
1134
|
|
|
1135
|
|
|
1136 static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
|
|
|
1137 expdesc e;
|
|
|
1138 check_condition(ls, vkisvar(lh->v.k), "syntax error");
|
|
|
1139 if (testnext(ls, ',')) { /* assignment -> ',' suffixedexp assignment */
|
|
|
1140 struct LHS_assign nv;
|
|
|
1141 nv.prev = lh;
|
|
|
1142 suffixedexp(ls, &nv.v);
|
|
|
1143 if (nv.v.k != VINDEXED)
|
|
|
1144 check_conflict(ls, lh, &nv.v);
|
|
|
1145 checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS,
|
|
|
1146 "C levels");
|
|
|
1147 assignment(ls, &nv, nvars+1);
|
|
|
1148 }
|
|
|
1149 else { /* assignment -> `=' explist */
|
|
|
1150 int nexps;
|
|
|
1151 checknext(ls, '=');
|
|
|
1152 nexps = explist(ls, &e);
|
|
|
1153 if (nexps != nvars) {
|
|
|
1154 adjust_assign(ls, nvars, nexps, &e);
|
|
|
1155 if (nexps > nvars)
|
|
|
1156 ls->fs->freereg -= nexps - nvars; /* remove extra values */
|
|
|
1157 }
|
|
|
1158 else {
|
|
|
1159 luaK_setoneret(ls->fs, &e); /* close last expression */
|
|
|
1160 luaK_storevar(ls->fs, &lh->v, &e);
|
|
|
1161 return; /* avoid default */
|
|
|
1162 }
|
|
|
1163 }
|
|
|
1164 init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
|
|
|
1165 luaK_storevar(ls->fs, &lh->v, &e);
|
|
|
1166 }
|
|
|
1167
|
|
|
1168
|
|
|
1169 static int cond (LexState *ls) {
|
|
|
1170 /* cond -> exp */
|
|
|
1171 expdesc v;
|
|
|
1172 expr(ls, &v); /* read condition */
|
|
|
1173 if (v.k == VNIL) v.k = VFALSE; /* `falses' are all equal here */
|
|
|
1174 luaK_goiftrue(ls->fs, &v);
|
|
|
1175 return v.f;
|
|
|
1176 }
|
|
|
1177
|
|
|
1178
|
|
|
1179 static void gotostat (LexState *ls, int pc) {
|
|
|
1180 int line = ls->linenumber;
|
|
|
1181 TString *label;
|
|
|
1182 int g;
|
|
|
1183 if (testnext(ls, TK_GOTO))
|
|
|
1184 label = str_checkname(ls);
|
|
|
1185 else {
|
|
|
1186 luaX_next(ls); /* skip break */
|
|
|
1187 label = luaS_new(ls->L, "break");
|
|
|
1188 }
|
|
|
1189 g = newlabelentry(ls, &ls->dyd->gt, label, line, pc);
|
|
|
1190 findlabel(ls, g); /* close it if label already defined */
|
|
|
1191 }
|
|
|
1192
|
|
|
1193
|
|
|
1194 /* check for repeated labels on the same block */
|
|
|
1195 static void checkrepeated (FuncState *fs, Labellist *ll, TString *label) {
|
|
|
1196 int i;
|
|
|
1197 for (i = fs->bl->firstlabel; i < ll->n; i++) {
|
|
|
1198 if (luaS_eqstr(label, ll->arr[i].name)) {
|
|
|
1199 const char *msg = luaO_pushfstring(fs->ls->L,
|
|
|
1200 "label " LUA_QS " already defined on line %d",
|
|
|
1201 getstr(label), ll->arr[i].line);
|
|
|
1202 semerror(fs->ls, msg);
|
|
|
1203 }
|
|
|
1204 }
|
|
|
1205 }
|
|
|
1206
|
|
|
1207
|
|
|
1208 /* skip no-op statements */
|
|
|
1209 static void skipnoopstat (LexState *ls) {
|
|
|
1210 while (ls->t.token == ';' || ls->t.token == TK_DBCOLON)
|
|
|
1211 statement(ls);
|
|
|
1212 }
|
|
|
1213
|
|
|
1214
|
|
|
1215 static void labelstat (LexState *ls, TString *label, int line) {
|
|
|
1216 /* label -> '::' NAME '::' */
|
|
|
1217 FuncState *fs = ls->fs;
|
|
|
1218 Labellist *ll = &ls->dyd->label;
|
|
|
1219 int l; /* index of new label being created */
|
|
|
1220 checkrepeated(fs, ll, label); /* check for repeated labels */
|
|
|
1221 checknext(ls, TK_DBCOLON); /* skip double colon */
|
|
|
1222 /* create new entry for this label */
|
|
|
1223 l = newlabelentry(ls, ll, label, line, fs->pc);
|
|
|
1224 skipnoopstat(ls); /* skip other no-op statements */
|
|
|
1225 if (block_follow(ls, 0)) { /* label is last no-op statement in the block? */
|
|
|
1226 /* assume that locals are already out of scope */
|
|
|
1227 ll->arr[l].nactvar = fs->bl->nactvar;
|
|
|
1228 }
|
|
|
1229 findgotos(ls, &ll->arr[l]);
|
|
|
1230 }
|
|
|
1231
|
|
|
1232
|
|
|
1233 static void whilestat (LexState *ls, int line) {
|
|
|
1234 /* whilestat -> WHILE cond DO block END */
|
|
|
1235 FuncState *fs = ls->fs;
|
|
|
1236 int whileinit;
|
|
|
1237 int condexit;
|
|
|
1238 BlockCnt bl;
|
|
|
1239 luaX_next(ls); /* skip WHILE */
|
|
|
1240 whileinit = luaK_getlabel(fs);
|
|
|
1241 condexit = cond(ls);
|
|
|
1242 enterblock(fs, &bl, 1);
|
|
|
1243 checknext(ls, TK_DO);
|
|
|
1244 block(ls);
|
|
|
1245 luaK_jumpto(fs, whileinit);
|
|
|
1246 check_match(ls, TK_END, TK_WHILE, line);
|
|
|
1247 leaveblock(fs);
|
|
|
1248 luaK_patchtohere(fs, condexit); /* false conditions finish the loop */
|
|
|
1249 }
|
|
|
1250
|
|
|
1251
|
|
|
1252 static void repeatstat (LexState *ls, int line) {
|
|
|
1253 /* repeatstat -> REPEAT block UNTIL cond */
|
|
|
1254 int condexit;
|
|
|
1255 FuncState *fs = ls->fs;
|
|
|
1256 int repeat_init = luaK_getlabel(fs);
|
|
|
1257 BlockCnt bl1, bl2;
|
|
|
1258 enterblock(fs, &bl1, 1); /* loop block */
|
|
|
1259 enterblock(fs, &bl2, 0); /* scope block */
|
|
|
1260 luaX_next(ls); /* skip REPEAT */
|
|
|
1261 statlist(ls);
|
|
|
1262 check_match(ls, TK_UNTIL, TK_REPEAT, line);
|
|
|
1263 condexit = cond(ls); /* read condition (inside scope block) */
|
|
|
1264 if (bl2.upval) /* upvalues? */
|
|
|
1265 luaK_patchclose(fs, condexit, bl2.nactvar);
|
|
|
1266 leaveblock(fs); /* finish scope */
|
|
|
1267 luaK_patchlist(fs, condexit, repeat_init); /* close the loop */
|
|
|
1268 leaveblock(fs); /* finish loop */
|
|
|
1269 }
|
|
|
1270
|
|
|
1271
|
|
|
1272 static int exp1 (LexState *ls) {
|
|
|
1273 expdesc e;
|
|
|
1274 int reg;
|
|
|
1275 expr(ls, &e);
|
|
|
1276 luaK_exp2nextreg(ls->fs, &e);
|
|
|
1277 lua_assert(e.k == VNONRELOC);
|
|
|
1278 reg = e.u.info;
|
|
|
1279 return reg;
|
|
|
1280 }
|
|
|
1281
|
|
|
1282
|
|
|
1283 static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
|
|
|
1284 /* forbody -> DO block */
|
|
|
1285 BlockCnt bl;
|
|
|
1286 FuncState *fs = ls->fs;
|
|
|
1287 int prep, endfor;
|
|
|
1288 adjustlocalvars(ls, 3); /* control variables */
|
|
|
1289 checknext(ls, TK_DO);
|
|
|
1290 prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs);
|
|
|
1291 enterblock(fs, &bl, 0); /* scope for declared variables */
|
|
|
1292 adjustlocalvars(ls, nvars);
|
|
|
1293 luaK_reserveregs(fs, nvars);
|
|
|
1294 block(ls);
|
|
|
1295 leaveblock(fs); /* end of scope for declared variables */
|
|
|
1296 luaK_patchtohere(fs, prep);
|
|
|
1297 if (isnum) /* numeric for? */
|
|
|
1298 endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP);
|
|
|
1299 else { /* generic for */
|
|
|
1300 luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars);
|
|
|
1301 luaK_fixline(fs, line);
|
|
|
1302 endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP);
|
|
|
1303 }
|
|
|
1304 luaK_patchlist(fs, endfor, prep + 1);
|
|
|
1305 luaK_fixline(fs, line);
|
|
|
1306 }
|
|
|
1307
|
|
|
1308
|
|
|
1309 static void fornum (LexState *ls, TString *varname, int line) {
|
|
|
1310 /* fornum -> NAME = exp1,exp1[,exp1] forbody */
|
|
|
1311 FuncState *fs = ls->fs;
|
|
|
1312 int base = fs->freereg;
|
|
|
1313 new_localvarliteral(ls, "(for index)");
|
|
|
1314 new_localvarliteral(ls, "(for limit)");
|
|
|
1315 new_localvarliteral(ls, "(for step)");
|
|
|
1316 new_localvar(ls, varname);
|
|
|
1317 checknext(ls, '=');
|
|
|
1318 exp1(ls); /* initial value */
|
|
|
1319 checknext(ls, ',');
|
|
|
1320 exp1(ls); /* limit */
|
|
|
1321 if (testnext(ls, ','))
|
|
|
1322 exp1(ls); /* optional step */
|
|
|
1323 else { /* default step = 1 */
|
|
|
1324 luaK_codek(fs, fs->freereg, luaK_numberK(fs, 1));
|
|
|
1325 luaK_reserveregs(fs, 1);
|
|
|
1326 }
|
|
|
1327 forbody(ls, base, line, 1, 1);
|
|
|
1328 }
|
|
|
1329
|
|
|
1330
|
|
|
1331 static void forlist (LexState *ls, TString *indexname) {
|
|
|
1332 /* forlist -> NAME {,NAME} IN explist forbody */
|
|
|
1333 FuncState *fs = ls->fs;
|
|
|
1334 expdesc e;
|
|
|
1335 int nvars = 4; /* gen, state, control, plus at least one declared var */
|
|
|
1336 int line;
|
|
|
1337 int base = fs->freereg;
|
|
|
1338 /* create control variables */
|
|
|
1339 new_localvarliteral(ls, "(for generator)");
|
|
|
1340 new_localvarliteral(ls, "(for state)");
|
|
|
1341 new_localvarliteral(ls, "(for control)");
|
|
|
1342 /* create declared variables */
|
|
|
1343 new_localvar(ls, indexname);
|
|
|
1344 while (testnext(ls, ',')) {
|
|
|
1345 new_localvar(ls, str_checkname(ls));
|
|
|
1346 nvars++;
|
|
|
1347 }
|
|
|
1348 checknext(ls, TK_IN);
|
|
|
1349 line = ls->linenumber;
|
|
|
1350 adjust_assign(ls, 3, explist(ls, &e), &e);
|
|
|
1351 luaK_checkstack(fs, 3); /* extra space to call generator */
|
|
|
1352 forbody(ls, base, line, nvars - 3, 0);
|
|
|
1353 }
|
|
|
1354
|
|
|
1355
|
|
|
1356 static void forstat (LexState *ls, int line) {
|
|
|
1357 /* forstat -> FOR (fornum | forlist) END */
|
|
|
1358 FuncState *fs = ls->fs;
|
|
|
1359 TString *varname;
|
|
|
1360 BlockCnt bl;
|
|
|
1361 enterblock(fs, &bl, 1); /* scope for loop and control variables */
|
|
|
1362 luaX_next(ls); /* skip `for' */
|
|
|
1363 varname = str_checkname(ls); /* first variable name */
|
|
|
1364 switch (ls->t.token) {
|
|
|
1365 case '=': fornum(ls, varname, line); break;
|
|
|
1366 case ',': case TK_IN: forlist(ls, varname); break;
|
|
|
1367 default: luaX_syntaxerror(ls, LUA_QL("=") " or " LUA_QL("in") " expected");
|
|
|
1368 }
|
|
|
1369 check_match(ls, TK_END, TK_FOR, line);
|
|
|
1370 leaveblock(fs); /* loop scope (`break' jumps to this point) */
|
|
|
1371 }
|
|
|
1372
|
|
|
1373
|
|
|
1374 static void test_then_block (LexState *ls, int *escapelist) {
|
|
|
1375 /* test_then_block -> [IF | ELSEIF] cond THEN block */
|
|
|
1376 BlockCnt bl;
|
|
|
1377 FuncState *fs = ls->fs;
|
|
|
1378 expdesc v;
|
|
|
1379 int jf; /* instruction to skip 'then' code (if condition is false) */
|
|
|
1380 luaX_next(ls); /* skip IF or ELSEIF */
|
|
|
1381 expr(ls, &v); /* read condition */
|
|
|
1382 checknext(ls, TK_THEN);
|
|
|
1383 if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) {
|
|
|
1384 luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */
|
|
|
1385 enterblock(fs, &bl, 0); /* must enter block before 'goto' */
|
|
|
1386 gotostat(ls, v.t); /* handle goto/break */
|
|
|
1387 skipnoopstat(ls); /* skip other no-op statements */
|
|
|
1388 if (block_follow(ls, 0)) { /* 'goto' is the entire block? */
|
|
|
1389 leaveblock(fs);
|
|
|
1390 return; /* and that is it */
|
|
|
1391 }
|
|
|
1392 else /* must skip over 'then' part if condition is false */
|
|
|
1393 jf = luaK_jump(fs);
|
|
|
1394 }
|
|
|
1395 else { /* regular case (not goto/break) */
|
|
|
1396 luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */
|
|
|
1397 enterblock(fs, &bl, 0);
|
|
|
1398 jf = v.f;
|
|
|
1399 }
|
|
|
1400 statlist(ls); /* `then' part */
|
|
|
1401 leaveblock(fs);
|
|
|
1402 if (ls->t.token == TK_ELSE ||
|
|
|
1403 ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */
|
|
|
1404 luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */
|
|
|
1405 luaK_patchtohere(fs, jf);
|
|
|
1406 }
|
|
|
1407
|
|
|
1408
|
|
|
1409 static void ifstat (LexState *ls, int line) {
|
|
|
1410 /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
|
|
|
1411 FuncState *fs = ls->fs;
|
|
|
1412 int escapelist = NO_JUMP; /* exit list for finished parts */
|
|
|
1413 test_then_block(ls, &escapelist); /* IF cond THEN block */
|
|
|
1414 while (ls->t.token == TK_ELSEIF)
|
|
|
1415 test_then_block(ls, &escapelist); /* ELSEIF cond THEN block */
|
|
|
1416 if (testnext(ls, TK_ELSE))
|
|
|
1417 block(ls); /* `else' part */
|
|
|
1418 check_match(ls, TK_END, TK_IF, line);
|
|
|
1419 luaK_patchtohere(fs, escapelist); /* patch escape list to 'if' end */
|
|
|
1420 }
|
|
|
1421
|
|
|
1422
|
|
|
1423 static void localfunc (LexState *ls) {
|
|
|
1424 expdesc b;
|
|
|
1425 FuncState *fs = ls->fs;
|
|
|
1426 new_localvar(ls, str_checkname(ls)); /* new local variable */
|
|
|
1427 adjustlocalvars(ls, 1); /* enter its scope */
|
|
|
1428 body(ls, &b, 0, ls->linenumber); /* function created in next register */
|
|
|
1429 /* debug information will only see the variable after this point! */
|
|
|
1430 getlocvar(fs, b.u.info)->startpc = fs->pc;
|
|
|
1431 }
|
|
|
1432
|
|
|
1433
|
|
|
1434 static void localstat (LexState *ls) {
|
|
|
1435 /* stat -> LOCAL NAME {`,' NAME} [`=' explist] */
|
|
|
1436 int nvars = 0;
|
|
|
1437 int nexps;
|
|
|
1438 expdesc e;
|
|
|
1439 do {
|
|
|
1440 new_localvar(ls, str_checkname(ls));
|
|
|
1441 nvars++;
|
|
|
1442 } while (testnext(ls, ','));
|
|
|
1443 if (testnext(ls, '='))
|
|
|
1444 nexps = explist(ls, &e);
|
|
|
1445 else {
|
|
|
1446 e.k = VVOID;
|
|
|
1447 nexps = 0;
|
|
|
1448 }
|
|
|
1449 adjust_assign(ls, nvars, nexps, &e);
|
|
|
1450 adjustlocalvars(ls, nvars);
|
|
|
1451 }
|
|
|
1452
|
|
|
1453
|
|
|
1454 static int funcname (LexState *ls, expdesc *v) {
|
|
|
1455 /* funcname -> NAME {fieldsel} [`:' NAME] */
|
|
|
1456 int ismethod = 0;
|
|
|
1457 singlevar(ls, v);
|
|
|
1458 while (ls->t.token == '.')
|
|
|
1459 fieldsel(ls, v);
|
|
|
1460 if (ls->t.token == ':') {
|
|
|
1461 ismethod = 1;
|
|
|
1462 fieldsel(ls, v);
|
|
|
1463 }
|
|
|
1464 return ismethod;
|
|
|
1465 }
|
|
|
1466
|
|
|
1467
|
|
|
1468 static void funcstat (LexState *ls, int line) {
|
|
|
1469 /* funcstat -> FUNCTION funcname body */
|
|
|
1470 int ismethod;
|
|
|
1471 expdesc v, b;
|
|
|
1472 luaX_next(ls); /* skip FUNCTION */
|
|
|
1473 ismethod = funcname(ls, &v);
|
|
|
1474 body(ls, &b, ismethod, line);
|
|
|
1475 luaK_storevar(ls->fs, &v, &b);
|
|
|
1476 luaK_fixline(ls->fs, line); /* definition `happens' in the first line */
|
|
|
1477 }
|
|
|
1478
|
|
|
1479
|
|
|
1480 static void exprstat (LexState *ls) {
|
|
|
1481 /* stat -> func | assignment */
|
|
|
1482 FuncState *fs = ls->fs;
|
|
|
1483 struct LHS_assign v;
|
|
|
1484 suffixedexp(ls, &v.v);
|
|
|
1485 if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */
|
|
|
1486 v.prev = NULL;
|
|
|
1487 assignment(ls, &v, 1);
|
|
|
1488 }
|
|
|
1489 else { /* stat -> func */
|
|
|
1490 check_condition(ls, v.v.k == VCALL, "syntax error");
|
|
|
1491 SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */
|
|
|
1492 }
|
|
|
1493 }
|
|
|
1494
|
|
|
1495
|
|
|
1496 static void retstat (LexState *ls) {
|
|
|
1497 /* stat -> RETURN [explist] [';'] */
|
|
|
1498 FuncState *fs = ls->fs;
|
|
|
1499 expdesc e;
|
|
|
1500 int first, nret; /* registers with returned values */
|
|
|
1501 if (block_follow(ls, 1) || ls->t.token == ';')
|
|
|
1502 first = nret = 0; /* return no values */
|
|
|
1503 else {
|
|
|
1504 nret = explist(ls, &e); /* optional return values */
|
|
|
1505 if (hasmultret(e.k)) {
|
|
|
1506 luaK_setmultret(fs, &e);
|
|
|
1507 if (e.k == VCALL && nret == 1) { /* tail call? */
|
|
|
1508 SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
|
|
|
1509 lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
|
|
|
1510 }
|
|
|
1511 first = fs->nactvar;
|
|
|
1512 nret = LUA_MULTRET; /* return all values */
|
|
|
1513 }
|
|
|
1514 else {
|
|
|
1515 if (nret == 1) /* only one single value? */
|
|
|
1516 first = luaK_exp2anyreg(fs, &e);
|
|
|
1517 else {
|
|
|
1518 luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */
|
|
|
1519 first = fs->nactvar; /* return all `active' values */
|
|
|
1520 lua_assert(nret == fs->freereg - first);
|
|
|
1521 }
|
|
|
1522 }
|
|
|
1523 }
|
|
|
1524 luaK_ret(fs, first, nret);
|
|
|
1525 testnext(ls, ';'); /* skip optional semicolon */
|
|
|
1526 }
|
|
|
1527
|
|
|
1528
|
|
|
1529 static void statement (LexState *ls) {
|
|
|
1530 int line = ls->linenumber; /* may be needed for error messages */
|
|
|
1531 enterlevel(ls);
|
|
|
1532 switch (ls->t.token) {
|
|
|
1533 case ';': { /* stat -> ';' (empty statement) */
|
|
|
1534 luaX_next(ls); /* skip ';' */
|
|
|
1535 break;
|
|
|
1536 }
|
|
|
1537 case TK_IF: { /* stat -> ifstat */
|
|
|
1538 ifstat(ls, line);
|
|
|
1539 break;
|
|
|
1540 }
|
|
|
1541 case TK_WHILE: { /* stat -> whilestat */
|
|
|
1542 whilestat(ls, line);
|
|
|
1543 break;
|
|
|
1544 }
|
|
|
1545 case TK_DO: { /* stat -> DO block END */
|
|
|
1546 luaX_next(ls); /* skip DO */
|
|
|
1547 block(ls);
|
|
|
1548 check_match(ls, TK_END, TK_DO, line);
|
|
|
1549 break;
|
|
|
1550 }
|
|
|
1551 case TK_FOR: { /* stat -> forstat */
|
|
|
1552 forstat(ls, line);
|
|
|
1553 break;
|
|
|
1554 }
|
|
|
1555 case TK_REPEAT: { /* stat -> repeatstat */
|
|
|
1556 repeatstat(ls, line);
|
|
|
1557 break;
|
|
|
1558 }
|
|
|
1559 case TK_FUNCTION: { /* stat -> funcstat */
|
|
|
1560 funcstat(ls, line);
|
|
|
1561 break;
|
|
|
1562 }
|
|
|
1563 case TK_LOCAL: { /* stat -> localstat */
|
|
|
1564 luaX_next(ls); /* skip LOCAL */
|
|
|
1565 if (testnext(ls, TK_FUNCTION)) /* local function? */
|
|
|
1566 localfunc(ls);
|
|
|
1567 else
|
|
|
1568 localstat(ls);
|
|
|
1569 break;
|
|
|
1570 }
|
|
|
1571 case TK_DBCOLON: { /* stat -> label */
|
|
|
1572 luaX_next(ls); /* skip double colon */
|
|
|
1573 labelstat(ls, str_checkname(ls), line);
|
|
|
1574 break;
|
|
|
1575 }
|
|
|
1576 case TK_RETURN: { /* stat -> retstat */
|
|
|
1577 luaX_next(ls); /* skip RETURN */
|
|
|
1578 retstat(ls);
|
|
|
1579 break;
|
|
|
1580 }
|
|
|
1581 case TK_BREAK: /* stat -> breakstat */
|
|
|
1582 case TK_GOTO: { /* stat -> 'goto' NAME */
|
|
|
1583 gotostat(ls, luaK_jump(ls->fs));
|
|
|
1584 break;
|
|
|
1585 }
|
|
|
1586 default: { /* stat -> func | assignment */
|
|
|
1587 exprstat(ls);
|
|
|
1588 break;
|
|
|
1589 }
|
|
|
1590 }
|
|
|
1591 lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg &&
|
|
|
1592 ls->fs->freereg >= ls->fs->nactvar);
|
|
|
1593 ls->fs->freereg = ls->fs->nactvar; /* free registers */
|
|
|
1594 leavelevel(ls);
|
|
|
1595 }
|
|
|
1596
|
|
|
1597 /* }====================================================================== */
|
|
|
1598
|
|
|
1599
|
|
|
1600 /*
|
|
|
1601 ** compiles the main function, which is a regular vararg function with an
|
|
|
1602 ** upvalue named LUA_ENV
|
|
|
1603 */
|
|
|
1604 static void mainfunc (LexState *ls, FuncState *fs) {
|
|
|
1605 BlockCnt bl;
|
|
|
1606 expdesc v;
|
|
|
1607 open_func(ls, fs, &bl);
|
|
|
1608 fs->f->is_vararg = 1; /* main function is always vararg */
|
|
|
1609 init_exp(&v, VLOCAL, 0); /* create and... */
|
|
|
1610 newupvalue(fs, ls->envn, &v); /* ...set environment upvalue */
|
|
|
1611 luaX_next(ls); /* read first token */
|
|
|
1612 statlist(ls); /* parse main body */
|
|
|
1613 check(ls, TK_EOS);
|
|
|
1614 close_func(ls);
|
|
|
1615 }
|
|
|
1616
|
|
|
1617
|
|
|
1618 Closure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
|
|
|
1619 Dyndata *dyd, const char *name, int firstchar) {
|
|
|
1620 LexState lexstate;
|
|
|
1621 FuncState funcstate;
|
|
|
1622 Closure *cl = luaF_newLclosure(L, 1); /* create main closure */
|
|
|
1623 /* anchor closure (to avoid being collected) */
|
|
|
1624 setclLvalue(L, L->top, cl);
|
|
|
1625 incr_top(L);
|
|
|
1626 funcstate.f = cl->l.p = luaF_newproto(L);
|
|
|
1627 funcstate.f->source = luaS_new(L, name); /* create and anchor TString */
|
|
|
1628 lexstate.buff = buff;
|
|
|
1629 lexstate.dyd = dyd;
|
|
|
1630 dyd->actvar.n = dyd->gt.n = dyd->label.n = 0;
|
|
|
1631 luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar);
|
|
|
1632 mainfunc(&lexstate, &funcstate);
|
|
|
1633 lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs);
|
|
|
1634 /* all scopes should be correctly finished */
|
|
|
1635 lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0);
|
|
|
1636 return cl; /* it's on the stack too */
|
|
|
1637 }
|
|
|
1638
|
