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1087
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1 /*
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2 ** $Id: lparser.c,v 2.128 2012/05/20 14:51:23 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=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 */
|
|
|
517 static void codeclosure (LexState *ls, expdesc *v) {
|
|
|
518 FuncState *fs = ls->fs->prev;
|
|
|
519 init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1));
|
|
|
520 luaK_exp2nextreg(fs, v); /* fix it at stack top (for GC) */
|
|
|
521 }
|
|
|
522
|
|
|
523
|
|
|
524 static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) {
|
|
|
525 lua_State *L = ls->L;
|
|
|
526 Proto *f;
|
|
|
527 fs->prev = ls->fs; /* linked list of funcstates */
|
|
|
528 fs->ls = ls;
|
|
|
529 ls->fs = fs;
|
|
|
530 fs->pc = 0;
|
|
|
531 fs->lasttarget = 0;
|
|
|
532 fs->jpc = NO_JUMP;
|
|
|
533 fs->freereg = 0;
|
|
|
534 fs->nk = 0;
|
|
|
535 fs->np = 0;
|
|
|
536 fs->nups = 0;
|
|
|
537 fs->nlocvars = 0;
|
|
|
538 fs->nactvar = 0;
|
|
|
539 fs->firstlocal = ls->dyd->actvar.n;
|
|
|
540 fs->bl = NULL;
|
|
|
541 f = fs->f;
|
|
|
542 f->source = ls->source;
|
|
|
543 f->maxstacksize = 2; /* registers 0/1 are always valid */
|
|
|
544 fs->h = luaH_new(L);
|
|
|
545 /* anchor table of constants (to avoid being collected) */
|
|
|
546 sethvalue2s(L, L->top, fs->h);
|
|
|
547 incr_top(L);
|
|
|
548 enterblock(fs, bl, 0);
|
|
|
549 }
|
|
|
550
|
|
|
551
|
|
|
552 static void close_func (LexState *ls) {
|
|
|
553 lua_State *L = ls->L;
|
|
|
554 FuncState *fs = ls->fs;
|
|
|
555 Proto *f = fs->f;
|
|
|
556 luaK_ret(fs, 0, 0); /* final return */
|
|
|
557 leaveblock(fs);
|
|
|
558 luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
|
|
|
559 f->sizecode = fs->pc;
|
|
|
560 luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
|
|
|
561 f->sizelineinfo = fs->pc;
|
|
|
562 luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue);
|
|
|
563 f->sizek = fs->nk;
|
|
|
564 luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *);
|
|
|
565 f->sizep = fs->np;
|
|
|
566 luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar);
|
|
|
567 f->sizelocvars = fs->nlocvars;
|
|
|
568 luaM_reallocvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc);
|
|
|
569 f->sizeupvalues = fs->nups;
|
|
|
570 lua_assert(fs->bl == NULL);
|
|
|
571 ls->fs = fs->prev;
|
|
|
572 /* last token read was anchored in defunct function; must re-anchor it */
|
|
|
573 anchor_token(ls);
|
|
|
574 L->top--; /* pop table of constants */
|
|
|
575 luaC_checkGC(L);
|
|
|
576 }
|
|
|
577
|
|
|
578
|
|
|
579
|
|
|
580 /*============================================================*/
|
|
|
581 /* GRAMMAR RULES */
|
|
|
582 /*============================================================*/
|
|
|
583
|
|
|
584
|
|
|
585 /*
|
|
|
586 ** check whether current token is in the follow set of a block.
|
|
|
587 ** 'until' closes syntactical blocks, but do not close scope,
|
|
|
588 ** so it handled in separate.
|
|
|
589 */
|
|
|
590 static int block_follow (LexState *ls, int withuntil) {
|
|
|
591 switch (ls->t.token) {
|
|
|
592 case TK_ELSE: case TK_ELSEIF:
|
|
|
593 case TK_END: case TK_EOS:
|
|
|
594 return 1;
|
|
|
595 case TK_UNTIL: return withuntil;
|
|
|
596 default: return 0;
|
|
|
597 }
|
|
|
598 }
|
|
|
599
|
|
|
600
|
|
|
601 static void statlist (LexState *ls) {
|
|
|
602 /* statlist -> { stat [`;'] } */
|
|
|
603 while (!block_follow(ls, 1)) {
|
|
|
604 if (ls->t.token == TK_RETURN) {
|
|
|
605 statement(ls);
|
|
|
606 return; /* 'return' must be last statement */
|
|
|
607 }
|
|
|
608 statement(ls);
|
|
|
609 }
|
|
|
610 }
|
|
|
611
|
|
|
612
|
|
|
613 static void fieldsel (LexState *ls, expdesc *v) {
|
|
|
614 /* fieldsel -> ['.' | ':'] NAME */
|
|
|
615 FuncState *fs = ls->fs;
|
|
|
616 expdesc key;
|
|
|
617 luaK_exp2anyregup(fs, v);
|
|
|
618 luaX_next(ls); /* skip the dot or colon */
|
|
|
619 checkname(ls, &key);
|
|
|
620 luaK_indexed(fs, v, &key);
|
|
|
621 }
|
|
|
622
|
|
|
623
|
|
|
624 static void yindex (LexState *ls, expdesc *v) {
|
|
|
625 /* index -> '[' expr ']' */
|
|
|
626 luaX_next(ls); /* skip the '[' */
|
|
|
627 expr(ls, v);
|
|
|
628 luaK_exp2val(ls->fs, v);
|
|
|
629 checknext(ls, ']');
|
|
|
630 }
|
|
|
631
|
|
|
632
|
|
|
633 /*
|
|
|
634 ** {======================================================================
|
|
|
635 ** Rules for Constructors
|
|
|
636 ** =======================================================================
|
|
|
637 */
|
|
|
638
|
|
|
639
|
|
|
640 struct ConsControl {
|
|
|
641 expdesc v; /* last list item read */
|
|
|
642 expdesc *t; /* table descriptor */
|
|
|
643 int nh; /* total number of `record' elements */
|
|
|
644 int na; /* total number of array elements */
|
|
|
645 int tostore; /* number of array elements pending to be stored */
|
|
|
646 };
|
|
|
647
|
|
|
648
|
|
|
649 static void recfield (LexState *ls, struct ConsControl *cc) {
|
|
|
650 /* recfield -> (NAME | `['exp1`]') = exp1 */
|
|
|
651 FuncState *fs = ls->fs;
|
|
|
652 int reg = ls->fs->freereg;
|
|
|
653 expdesc key, val;
|
|
|
654 int rkkey;
|
|
|
655 if (ls->t.token == TK_NAME) {
|
|
|
656 checklimit(fs, cc->nh, MAX_INT, "items in a constructor");
|
|
|
657 checkname(ls, &key);
|
|
|
658 }
|
|
|
659 else /* ls->t.token == '[' */
|
|
|
660 yindex(ls, &key);
|
|
|
661 cc->nh++;
|
|
|
662 checknext(ls, '=');
|
|
|
663 rkkey = luaK_exp2RK(fs, &key);
|
|
|
664 expr(ls, &val);
|
|
|
665 luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val));
|
|
|
666 fs->freereg = reg; /* free registers */
|
|
|
667 }
|
|
|
668
|
|
|
669
|
|
|
670 static void closelistfield (FuncState *fs, struct ConsControl *cc) {
|
|
|
671 if (cc->v.k == VVOID) return; /* there is no list item */
|
|
|
672 luaK_exp2nextreg(fs, &cc->v);
|
|
|
673 cc->v.k = VVOID;
|
|
|
674 if (cc->tostore == LFIELDS_PER_FLUSH) {
|
|
|
675 luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); /* flush */
|
|
|
676 cc->tostore = 0; /* no more items pending */
|
|
|
677 }
|
|
|
678 }
|
|
|
679
|
|
|
680
|
|
|
681 static void lastlistfield (FuncState *fs, struct ConsControl *cc) {
|
|
|
682 if (cc->tostore == 0) return;
|
|
|
683 if (hasmultret(cc->v.k)) {
|
|
|
684 luaK_setmultret(fs, &cc->v);
|
|
|
685 luaK_setlist(fs, cc->t->u.info, cc->na, LUA_MULTRET);
|
|
|
686 cc->na--; /* do not count last expression (unknown number of elements) */
|
|
|
687 }
|
|
|
688 else {
|
|
|
689 if (cc->v.k != VVOID)
|
|
|
690 luaK_exp2nextreg(fs, &cc->v);
|
|
|
691 luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore);
|
|
|
692 }
|
|
|
693 }
|
|
|
694
|
|
|
695
|
|
|
696 static void listfield (LexState *ls, struct ConsControl *cc) {
|
|
|
697 /* listfield -> exp */
|
|
|
698 expr(ls, &cc->v);
|
|
|
699 checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor");
|
|
|
700 cc->na++;
|
|
|
701 cc->tostore++;
|
|
|
702 }
|
|
|
703
|
|
|
704
|
|
|
705 static void field (LexState *ls, struct ConsControl *cc) {
|
|
|
706 /* field -> listfield | recfield */
|
|
|
707 switch(ls->t.token) {
|
|
|
708 case TK_NAME: { /* may be 'listfield' or 'recfield' */
|
|
|
709 if (luaX_lookahead(ls) != '=') /* expression? */
|
|
|
710 listfield(ls, cc);
|
|
|
711 else
|
|
|
712 recfield(ls, cc);
|
|
|
713 break;
|
|
|
714 }
|
|
|
715 case '[': {
|
|
|
716 recfield(ls, cc);
|
|
|
717 break;
|
|
|
718 }
|
|
|
719 default: {
|
|
|
720 listfield(ls, cc);
|
|
|
721 break;
|
|
|
722 }
|
|
|
723 }
|
|
|
724 }
|
|
|
725
|
|
|
726
|
|
|
727 static void constructor (LexState *ls, expdesc *t) {
|
|
|
728 /* constructor -> '{' [ field { sep field } [sep] ] '}'
|
|
|
729 sep -> ',' | ';' */
|
|
|
730 FuncState *fs = ls->fs;
|
|
|
731 int line = ls->linenumber;
|
|
|
732 int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0);
|
|
|
733 struct ConsControl cc;
|
|
|
734 cc.na = cc.nh = cc.tostore = 0;
|
|
|
735 cc.t = t;
|
|
|
736 init_exp(t, VRELOCABLE, pc);
|
|
|
737 init_exp(&cc.v, VVOID, 0); /* no value (yet) */
|
|
|
738 luaK_exp2nextreg(ls->fs, t); /* fix it at stack top */
|
|
|
739 checknext(ls, '{');
|
|
|
740 do {
|
|
|
741 lua_assert(cc.v.k == VVOID || cc.tostore > 0);
|
|
|
742 if (ls->t.token == '}') break;
|
|
|
743 closelistfield(fs, &cc);
|
|
|
744 field(ls, &cc);
|
|
|
745 } while (testnext(ls, ',') || testnext(ls, ';'));
|
|
|
746 check_match(ls, '}', '{', line);
|
|
|
747 lastlistfield(fs, &cc);
|
|
|
748 SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */
|
|
|
749 SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh)); /* set initial table size */
|
|
|
750 }
|
|
|
751
|
|
|
752 /* }====================================================================== */
|
|
|
753
|
|
|
754
|
|
|
755
|
|
|
756 static void parlist (LexState *ls) {
|
|
|
757 /* parlist -> [ param { `,' param } ] */
|
|
|
758 FuncState *fs = ls->fs;
|
|
|
759 Proto *f = fs->f;
|
|
|
760 int nparams = 0;
|
|
|
761 f->is_vararg = 0;
|
|
|
762 if (ls->t.token != ')') { /* is `parlist' not empty? */
|
|
|
763 do {
|
|
|
764 switch (ls->t.token) {
|
|
|
765 case TK_NAME: { /* param -> NAME */
|
|
|
766 new_localvar(ls, str_checkname(ls));
|
|
|
767 nparams++;
|
|
|
768 break;
|
|
|
769 }
|
|
|
770 case TK_DOTS: { /* param -> `...' */
|
|
|
771 luaX_next(ls);
|
|
|
772 f->is_vararg = 1;
|
|
|
773 break;
|
|
|
774 }
|
|
|
775 default: luaX_syntaxerror(ls, "<name> or " LUA_QL("...") " expected");
|
|
|
776 }
|
|
|
777 } while (!f->is_vararg && testnext(ls, ','));
|
|
|
778 }
|
|
|
779 adjustlocalvars(ls, nparams);
|
|
|
780 f->numparams = cast_byte(fs->nactvar);
|
|
|
781 luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */
|
|
|
782 }
|
|
|
783
|
|
|
784
|
|
|
785 static void body (LexState *ls, expdesc *e, int ismethod, int line) {
|
|
|
786 /* body -> `(' parlist `)' block END */
|
|
|
787 FuncState new_fs;
|
|
|
788 BlockCnt bl;
|
|
|
789 new_fs.f = addprototype(ls);
|
|
|
790 new_fs.f->linedefined = line;
|
|
|
791 open_func(ls, &new_fs, &bl);
|
|
|
792 checknext(ls, '(');
|
|
|
793 if (ismethod) {
|
|
|
794 new_localvarliteral(ls, "self"); /* create 'self' parameter */
|
|
|
795 adjustlocalvars(ls, 1);
|
|
|
796 }
|
|
|
797 parlist(ls);
|
|
|
798 checknext(ls, ')');
|
|
|
799 statlist(ls);
|
|
|
800 new_fs.f->lastlinedefined = ls->linenumber;
|
|
|
801 check_match(ls, TK_END, TK_FUNCTION, line);
|
|
|
802 codeclosure(ls, e);
|
|
|
803 close_func(ls);
|
|
|
804 }
|
|
|
805
|
|
|
806
|
|
|
807 static int explist (LexState *ls, expdesc *v) {
|
|
|
808 /* explist -> expr { `,' expr } */
|
|
|
809 int n = 1; /* at least one expression */
|
|
|
810 expr(ls, v);
|
|
|
811 while (testnext(ls, ',')) {
|
|
|
812 luaK_exp2nextreg(ls->fs, v);
|
|
|
813 expr(ls, v);
|
|
|
814 n++;
|
|
|
815 }
|
|
|
816 return n;
|
|
|
817 }
|
|
|
818
|
|
|
819
|
|
|
820 static void funcargs (LexState *ls, expdesc *f, int line) {
|
|
|
821 FuncState *fs = ls->fs;
|
|
|
822 expdesc args;
|
|
|
823 int base, nparams;
|
|
|
824 switch (ls->t.token) {
|
|
|
825 case '(': { /* funcargs -> `(' [ explist ] `)' */
|
|
|
826 luaX_next(ls);
|
|
|
827 if (ls->t.token == ')') /* arg list is empty? */
|
|
|
828 args.k = VVOID;
|
|
|
829 else {
|
|
|
830 explist(ls, &args);
|
|
|
831 luaK_setmultret(fs, &args);
|
|
|
832 }
|
|
|
833 check_match(ls, ')', '(', line);
|
|
|
834 break;
|
|
|
835 }
|
|
|
836 case '{': { /* funcargs -> constructor */
|
|
|
837 constructor(ls, &args);
|
|
|
838 break;
|
|
|
839 }
|
|
|
840 case TK_STRING: { /* funcargs -> STRING */
|
|
|
841 codestring(ls, &args, ls->t.seminfo.ts);
|
|
|
842 luaX_next(ls); /* must use `seminfo' before `next' */
|
|
|
843 break;
|
|
|
844 }
|
|
|
845 default: {
|
|
|
846 luaX_syntaxerror(ls, "function arguments expected");
|
|
|
847 }
|
|
|
848 }
|
|
|
849 lua_assert(f->k == VNONRELOC);
|
|
|
850 base = f->u.info; /* base register for call */
|
|
|
851 if (hasmultret(args.k))
|
|
|
852 nparams = LUA_MULTRET; /* open call */
|
|
|
853 else {
|
|
|
854 if (args.k != VVOID)
|
|
|
855 luaK_exp2nextreg(fs, &args); /* close last argument */
|
|
|
856 nparams = fs->freereg - (base+1);
|
|
|
857 }
|
|
|
858 init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2));
|
|
|
859 luaK_fixline(fs, line);
|
|
|
860 fs->freereg = base+1; /* call remove function and arguments and leaves
|
|
|
861 (unless changed) one result */
|
|
|
862 }
|
|
|
863
|
|
|
864
|
|
|
865
|
|
|
866
|
|
|
867 /*
|
|
|
868 ** {======================================================================
|
|
|
869 ** Expression parsing
|
|
|
870 ** =======================================================================
|
|
|
871 */
|
|
|
872
|
|
|
873
|
|
|
874 static void primaryexp (LexState *ls, expdesc *v) {
|
|
|
875 /* primaryexp -> NAME | '(' expr ')' */
|
|
|
876 switch (ls->t.token) {
|
|
|
877 case '(': {
|
|
|
878 int line = ls->linenumber;
|
|
|
879 luaX_next(ls);
|
|
|
880 expr(ls, v);
|
|
|
881 check_match(ls, ')', '(', line);
|
|
|
882 luaK_dischargevars(ls->fs, v);
|
|
|
883 return;
|
|
|
884 }
|
|
|
885 case TK_NAME: {
|
|
|
886 singlevar(ls, v);
|
|
|
887 return;
|
|
|
888 }
|
|
|
889 default: {
|
|
|
890 luaX_syntaxerror(ls, "unexpected symbol");
|
|
|
891 }
|
|
|
892 }
|
|
|
893 }
|
|
|
894
|
|
|
895
|
|
|
896 static void suffixedexp (LexState *ls, expdesc *v) {
|
|
|
897 /* suffixedexp ->
|
|
|
898 primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */
|
|
|
899 FuncState *fs = ls->fs;
|
|
|
900 int line = ls->linenumber;
|
|
|
901 primaryexp(ls, v);
|
|
|
902 for (;;) {
|
|
|
903 switch (ls->t.token) {
|
|
|
904 case '.': { /* fieldsel */
|
|
|
905 fieldsel(ls, v);
|
|
|
906 break;
|
|
|
907 }
|
|
|
908 case '[': { /* `[' exp1 `]' */
|
|
|
909 expdesc key;
|
|
|
910 luaK_exp2anyregup(fs, v);
|
|
|
911 yindex(ls, &key);
|
|
|
912 luaK_indexed(fs, v, &key);
|
|
|
913 break;
|
|
|
914 }
|
|
|
915 case ':': { /* `:' NAME funcargs */
|
|
|
916 expdesc key;
|
|
|
917 luaX_next(ls);
|
|
|
918 checkname(ls, &key);
|
|
|
919 luaK_self(fs, v, &key);
|
|
|
920 funcargs(ls, v, line);
|
|
|
921 break;
|
|
|
922 }
|
|
|
923 case '(': case TK_STRING: case '{': { /* funcargs */
|
|
|
924 luaK_exp2nextreg(fs, v);
|
|
|
925 funcargs(ls, v, line);
|
|
|
926 break;
|
|
|
927 }
|
|
|
928 default: return;
|
|
|
929 }
|
|
|
930 }
|
|
|
931 }
|
|
|
932
|
|
|
933
|
|
|
934 static void simpleexp (LexState *ls, expdesc *v) {
|
|
|
935 /* simpleexp -> NUMBER | STRING | NIL | TRUE | FALSE | ... |
|
|
|
936 constructor | FUNCTION body | suffixedexp */
|
|
|
937 switch (ls->t.token) {
|
|
|
938 case TK_NUMBER: {
|
|
|
939 init_exp(v, VKNUM, 0);
|
|
|
940 v->u.nval = ls->t.seminfo.r;
|
|
|
941 break;
|
|
|
942 }
|
|
|
943 case TK_STRING: {
|
|
|
944 codestring(ls, v, ls->t.seminfo.ts);
|
|
|
945 break;
|
|
|
946 }
|
|
|
947 case TK_NIL: {
|
|
|
948 init_exp(v, VNIL, 0);
|
|
|
949 break;
|
|
|
950 }
|
|
|
951 case TK_TRUE: {
|
|
|
952 init_exp(v, VTRUE, 0);
|
|
|
953 break;
|
|
|
954 }
|
|
|
955 case TK_FALSE: {
|
|
|
956 init_exp(v, VFALSE, 0);
|
|
|
957 break;
|
|
|
958 }
|
|
|
959 case TK_DOTS: { /* vararg */
|
|
|
960 FuncState *fs = ls->fs;
|
|
|
961 check_condition(ls, fs->f->is_vararg,
|
|
|
962 "cannot use " LUA_QL("...") " outside a vararg function");
|
|
|
963 init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0));
|
|
|
964 break;
|
|
|
965 }
|
|
|
966 case '{': { /* constructor */
|
|
|
967 constructor(ls, v);
|
|
|
968 return;
|
|
|
969 }
|
|
|
970 case TK_FUNCTION: {
|
|
|
971 luaX_next(ls);
|
|
|
972 body(ls, v, 0, ls->linenumber);
|
|
|
973 return;
|
|
|
974 }
|
|
|
975 default: {
|
|
|
976 suffixedexp(ls, v);
|
|
|
977 return;
|
|
|
978 }
|
|
|
979 }
|
|
|
980 luaX_next(ls);
|
|
|
981 }
|
|
|
982
|
|
|
983
|
|
|
984 static UnOpr getunopr (int op) {
|
|
|
985 switch (op) {
|
|
|
986 case TK_NOT: return OPR_NOT;
|
|
|
987 case '-': return OPR_MINUS;
|
|
|
988 case '#': return OPR_LEN;
|
|
|
989 default: return OPR_NOUNOPR;
|
|
|
990 }
|
|
|
991 }
|
|
|
992
|
|
|
993
|
|
|
994 static BinOpr getbinopr (int op) {
|
|
|
995 switch (op) {
|
|
|
996 case '+': return OPR_ADD;
|
|
|
997 case '-': return OPR_SUB;
|
|
|
998 case '*': return OPR_MUL;
|
|
|
999 case '/': return OPR_DIV;
|
|
|
1000 case '%': return OPR_MOD;
|
|
|
1001 case '^': return OPR_POW;
|
|
|
1002 case TK_CONCAT: return OPR_CONCAT;
|
|
|
1003 case TK_NE: return OPR_NE;
|
|
|
1004 case TK_EQ: return OPR_EQ;
|
|
|
1005 case '<': return OPR_LT;
|
|
|
1006 case TK_LE: return OPR_LE;
|
|
|
1007 case '>': return OPR_GT;
|
|
|
1008 case TK_GE: return OPR_GE;
|
|
|
1009 case TK_AND: return OPR_AND;
|
|
|
1010 case TK_OR: return OPR_OR;
|
|
|
1011 default: return OPR_NOBINOPR;
|
|
|
1012 }
|
|
|
1013 }
|
|
|
1014
|
|
|
1015
|
|
|
1016 static const struct {
|
|
|
1017 lu_byte left; /* left priority for each binary operator */
|
|
|
1018 lu_byte right; /* right priority */
|
|
|
1019 } priority[] = { /* ORDER OPR */
|
|
|
1020 {6, 6}, {6, 6}, {7, 7}, {7, 7}, {7, 7}, /* `+' `-' `*' `/' `%' */
|
|
|
1021 {10, 9}, {5, 4}, /* ^, .. (right associative) */
|
|
|
1022 {3, 3}, {3, 3}, {3, 3}, /* ==, <, <= */
|
|
|
1023 {3, 3}, {3, 3}, {3, 3}, /* ~=, >, >= */
|
|
|
1024 {2, 2}, {1, 1} /* and, or */
|
|
|
1025 };
|
|
|
1026
|
|
|
1027 #define UNARY_PRIORITY 8 /* priority for unary operators */
|
|
|
1028
|
|
|
1029
|
|
|
1030 /*
|
|
|
1031 ** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
|
|
|
1032 ** where `binop' is any binary operator with a priority higher than `limit'
|
|
|
1033 */
|
|
|
1034 static BinOpr subexpr (LexState *ls, expdesc *v, int limit) {
|
|
|
1035 BinOpr op;
|
|
|
1036 UnOpr uop;
|
|
|
1037 enterlevel(ls);
|
|
|
1038 uop = getunopr(ls->t.token);
|
|
|
1039 if (uop != OPR_NOUNOPR) {
|
|
|
1040 int line = ls->linenumber;
|
|
|
1041 luaX_next(ls);
|
|
|
1042 subexpr(ls, v, UNARY_PRIORITY);
|
|
|
1043 luaK_prefix(ls->fs, uop, v, line);
|
|
|
1044 }
|
|
|
1045 else simpleexp(ls, v);
|
|
|
1046 /* expand while operators have priorities higher than `limit' */
|
|
|
1047 op = getbinopr(ls->t.token);
|
|
|
1048 while (op != OPR_NOBINOPR && priority[op].left > limit) {
|
|
|
1049 expdesc v2;
|
|
|
1050 BinOpr nextop;
|
|
|
1051 int line = ls->linenumber;
|
|
|
1052 luaX_next(ls);
|
|
|
1053 luaK_infix(ls->fs, op, v);
|
|
|
1054 /* read sub-expression with higher priority */
|
|
|
1055 nextop = subexpr(ls, &v2, priority[op].right);
|
|
|
1056 luaK_posfix(ls->fs, op, v, &v2, line);
|
|
|
1057 op = nextop;
|
|
|
1058 }
|
|
|
1059 leavelevel(ls);
|
|
|
1060 return op; /* return first untreated operator */
|
|
|
1061 }
|
|
|
1062
|
|
|
1063
|
|
|
1064 static void expr (LexState *ls, expdesc *v) {
|
|
|
1065 subexpr(ls, v, 0);
|
|
|
1066 }
|
|
|
1067
|
|
|
1068 /* }==================================================================== */
|
|
|
1069
|
|
|
1070
|
|
|
1071
|
|
|
1072 /*
|
|
|
1073 ** {======================================================================
|
|
|
1074 ** Rules for Statements
|
|
|
1075 ** =======================================================================
|
|
|
1076 */
|
|
|
1077
|
|
|
1078
|
|
|
1079 static void block (LexState *ls) {
|
|
|
1080 /* block -> statlist */
|
|
|
1081 FuncState *fs = ls->fs;
|
|
|
1082 BlockCnt bl;
|
|
|
1083 enterblock(fs, &bl, 0);
|
|
|
1084 statlist(ls);
|
|
|
1085 leaveblock(fs);
|
|
|
1086 }
|
|
|
1087
|
|
|
1088
|
|
|
1089 /*
|
|
|
1090 ** structure to chain all variables in the left-hand side of an
|
|
|
1091 ** assignment
|
|
|
1092 */
|
|
|
1093 struct LHS_assign {
|
|
|
1094 struct LHS_assign *prev;
|
|
|
1095 expdesc v; /* variable (global, local, upvalue, or indexed) */
|
|
|
1096 };
|
|
|
1097
|
|
|
1098
|
|
|
1099 /*
|
|
|
1100 ** check whether, in an assignment to an upvalue/local variable, the
|
|
|
1101 ** upvalue/local variable is begin used in a previous assignment to a
|
|
|
1102 ** table. If so, save original upvalue/local value in a safe place and
|
|
|
1103 ** use this safe copy in the previous assignment.
|
|
|
1104 */
|
|
|
1105 static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) {
|
|
|
1106 FuncState *fs = ls->fs;
|
|
|
1107 int extra = fs->freereg; /* eventual position to save local variable */
|
|
|
1108 int conflict = 0;
|
|
|
1109 for (; lh; lh = lh->prev) { /* check all previous assignments */
|
|
|
1110 if (lh->v.k == VINDEXED) { /* assigning to a table? */
|
|
|
1111 /* table is the upvalue/local being assigned now? */
|
|
|
1112 if (lh->v.u.ind.vt == v->k && lh->v.u.ind.t == v->u.info) {
|
|
|
1113 conflict = 1;
|
|
|
1114 lh->v.u.ind.vt = VLOCAL;
|
|
|
1115 lh->v.u.ind.t = extra; /* previous assignment will use safe copy */
|
|
|
1116 }
|
|
|
1117 /* index is the local being assigned? (index cannot be upvalue) */
|
|
|
1118 if (v->k == VLOCAL && lh->v.u.ind.idx == v->u.info) {
|
|
|
1119 conflict = 1;
|
|
|
1120 lh->v.u.ind.idx = extra; /* previous assignment will use safe copy */
|
|
|
1121 }
|
|
|
1122 }
|
|
|
1123 }
|
|
|
1124 if (conflict) {
|
|
|
1125 /* copy upvalue/local value to a temporary (in position 'extra') */
|
|
|
1126 OpCode op = (v->k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
|
|
|
1127 luaK_codeABC(fs, op, extra, v->u.info, 0);
|
|
|
1128 luaK_reserveregs(fs, 1);
|
|
|
1129 }
|
|
|
1130 }
|
|
|
1131
|
|
|
1132
|
|
|
1133 static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
|
|
|
1134 expdesc e;
|
|
|
1135 check_condition(ls, vkisvar(lh->v.k), "syntax error");
|
|
|
1136 if (testnext(ls, ',')) { /* assignment -> ',' suffixedexp assignment */
|
|
|
1137 struct LHS_assign nv;
|
|
|
1138 nv.prev = lh;
|
|
|
1139 suffixedexp(ls, &nv.v);
|
|
|
1140 if (nv.v.k != VINDEXED)
|
|
|
1141 check_conflict(ls, lh, &nv.v);
|
|
|
1142 checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS,
|
|
|
1143 "C levels");
|
|
|
1144 assignment(ls, &nv, nvars+1);
|
|
|
1145 }
|
|
|
1146 else { /* assignment -> `=' explist */
|
|
|
1147 int nexps;
|
|
|
1148 checknext(ls, '=');
|
|
|
1149 nexps = explist(ls, &e);
|
|
|
1150 if (nexps != nvars) {
|
|
|
1151 adjust_assign(ls, nvars, nexps, &e);
|
|
|
1152 if (nexps > nvars)
|
|
|
1153 ls->fs->freereg -= nexps - nvars; /* remove extra values */
|
|
|
1154 }
|
|
|
1155 else {
|
|
|
1156 luaK_setoneret(ls->fs, &e); /* close last expression */
|
|
|
1157 luaK_storevar(ls->fs, &lh->v, &e);
|
|
|
1158 return; /* avoid default */
|
|
|
1159 }
|
|
|
1160 }
|
|
|
1161 init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
|
|
|
1162 luaK_storevar(ls->fs, &lh->v, &e);
|
|
|
1163 }
|
|
|
1164
|
|
|
1165
|
|
|
1166 static int cond (LexState *ls) {
|
|
|
1167 /* cond -> exp */
|
|
|
1168 expdesc v;
|
|
|
1169 expr(ls, &v); /* read condition */
|
|
|
1170 if (v.k == VNIL) v.k = VFALSE; /* `falses' are all equal here */
|
|
|
1171 luaK_goiftrue(ls->fs, &v);
|
|
|
1172 return v.f;
|
|
|
1173 }
|
|
|
1174
|
|
|
1175
|
|
|
1176 static void gotostat (LexState *ls, int pc) {
|
|
|
1177 int line = ls->linenumber;
|
|
|
1178 TString *label;
|
|
|
1179 int g;
|
|
|
1180 if (testnext(ls, TK_GOTO))
|
|
|
1181 label = str_checkname(ls);
|
|
|
1182 else {
|
|
|
1183 luaX_next(ls); /* skip break */
|
|
|
1184 label = luaS_new(ls->L, "break");
|
|
|
1185 }
|
|
|
1186 g = newlabelentry(ls, &ls->dyd->gt, label, line, pc);
|
|
|
1187 findlabel(ls, g); /* close it if label already defined */
|
|
|
1188 }
|
|
|
1189
|
|
|
1190
|
|
|
1191 /* check for repeated labels on the same block */
|
|
|
1192 static void checkrepeated (FuncState *fs, Labellist *ll, TString *label) {
|
|
|
1193 int i;
|
|
|
1194 for (i = fs->bl->firstlabel; i < ll->n; i++) {
|
|
|
1195 if (luaS_eqstr(label, ll->arr[i].name)) {
|
|
|
1196 const char *msg = luaO_pushfstring(fs->ls->L,
|
|
|
1197 "label " LUA_QS " already defined on line %d",
|
|
|
1198 getstr(label), ll->arr[i].line);
|
|
|
1199 semerror(fs->ls, msg);
|
|
|
1200 }
|
|
|
1201 }
|
|
|
1202 }
|
|
|
1203
|
|
|
1204
|
|
|
1205 /* skip no-op statements */
|
|
|
1206 static void skipnoopstat (LexState *ls) {
|
|
|
1207 while (ls->t.token == ';' || ls->t.token == TK_DBCOLON)
|
|
|
1208 statement(ls);
|
|
|
1209 }
|
|
|
1210
|
|
|
1211
|
|
|
1212 static void labelstat (LexState *ls, TString *label, int line) {
|
|
|
1213 /* label -> '::' NAME '::' */
|
|
|
1214 FuncState *fs = ls->fs;
|
|
|
1215 Labellist *ll = &ls->dyd->label;
|
|
|
1216 int l; /* index of new label being created */
|
|
|
1217 checkrepeated(fs, ll, label); /* check for repeated labels */
|
|
|
1218 checknext(ls, TK_DBCOLON); /* skip double colon */
|
|
|
1219 /* create new entry for this label */
|
|
|
1220 l = newlabelentry(ls, ll, label, line, fs->pc);
|
|
|
1221 skipnoopstat(ls); /* skip other no-op statements */
|
|
|
1222 if (block_follow(ls, 0)) { /* label is last no-op statement in the block? */
|
|
|
1223 /* assume that locals are already out of scope */
|
|
|
1224 ll->arr[l].nactvar = fs->bl->nactvar;
|
|
|
1225 }
|
|
|
1226 findgotos(ls, &ll->arr[l]);
|
|
|
1227 }
|
|
|
1228
|
|
|
1229
|
|
|
1230 static void whilestat (LexState *ls, int line) {
|
|
|
1231 /* whilestat -> WHILE cond DO block END */
|
|
|
1232 FuncState *fs = ls->fs;
|
|
|
1233 int whileinit;
|
|
|
1234 int condexit;
|
|
|
1235 BlockCnt bl;
|
|
|
1236 luaX_next(ls); /* skip WHILE */
|
|
|
1237 whileinit = luaK_getlabel(fs);
|
|
|
1238 condexit = cond(ls);
|
|
|
1239 enterblock(fs, &bl, 1);
|
|
|
1240 checknext(ls, TK_DO);
|
|
|
1241 block(ls);
|
|
|
1242 luaK_jumpto(fs, whileinit);
|
|
|
1243 check_match(ls, TK_END, TK_WHILE, line);
|
|
|
1244 leaveblock(fs);
|
|
|
1245 luaK_patchtohere(fs, condexit); /* false conditions finish the loop */
|
|
|
1246 }
|
|
|
1247
|
|
|
1248
|
|
|
1249 static void repeatstat (LexState *ls, int line) {
|
|
|
1250 /* repeatstat -> REPEAT block UNTIL cond */
|
|
|
1251 int condexit;
|
|
|
1252 FuncState *fs = ls->fs;
|
|
|
1253 int repeat_init = luaK_getlabel(fs);
|
|
|
1254 BlockCnt bl1, bl2;
|
|
|
1255 enterblock(fs, &bl1, 1); /* loop block */
|
|
|
1256 enterblock(fs, &bl2, 0); /* scope block */
|
|
|
1257 luaX_next(ls); /* skip REPEAT */
|
|
|
1258 statlist(ls);
|
|
|
1259 check_match(ls, TK_UNTIL, TK_REPEAT, line);
|
|
|
1260 condexit = cond(ls); /* read condition (inside scope block) */
|
|
|
1261 if (bl2.upval) /* upvalues? */
|
|
|
1262 luaK_patchclose(fs, condexit, bl2.nactvar);
|
|
|
1263 leaveblock(fs); /* finish scope */
|
|
|
1264 luaK_patchlist(fs, condexit, repeat_init); /* close the loop */
|
|
|
1265 leaveblock(fs); /* finish loop */
|
|
|
1266 }
|
|
|
1267
|
|
|
1268
|
|
|
1269 static int exp1 (LexState *ls) {
|
|
|
1270 expdesc e;
|
|
|
1271 int reg;
|
|
|
1272 expr(ls, &e);
|
|
|
1273 luaK_exp2nextreg(ls->fs, &e);
|
|
|
1274 lua_assert(e.k == VNONRELOC);
|
|
|
1275 reg = e.u.info;
|
|
|
1276 return reg;
|
|
|
1277 }
|
|
|
1278
|
|
|
1279
|
|
|
1280 static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
|
|
|
1281 /* forbody -> DO block */
|
|
|
1282 BlockCnt bl;
|
|
|
1283 FuncState *fs = ls->fs;
|
|
|
1284 int prep, endfor;
|
|
|
1285 adjustlocalvars(ls, 3); /* control variables */
|
|
|
1286 checknext(ls, TK_DO);
|
|
|
1287 prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs);
|
|
|
1288 enterblock(fs, &bl, 0); /* scope for declared variables */
|
|
|
1289 adjustlocalvars(ls, nvars);
|
|
|
1290 luaK_reserveregs(fs, nvars);
|
|
|
1291 block(ls);
|
|
|
1292 leaveblock(fs); /* end of scope for declared variables */
|
|
|
1293 luaK_patchtohere(fs, prep);
|
|
|
1294 if (isnum) /* numeric for? */
|
|
|
1295 endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP);
|
|
|
1296 else { /* generic for */
|
|
|
1297 luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars);
|
|
|
1298 luaK_fixline(fs, line);
|
|
|
1299 endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP);
|
|
|
1300 }
|
|
|
1301 luaK_patchlist(fs, endfor, prep + 1);
|
|
|
1302 luaK_fixline(fs, line);
|
|
|
1303 }
|
|
|
1304
|
|
|
1305
|
|
|
1306 static void fornum (LexState *ls, TString *varname, int line) {
|
|
|
1307 /* fornum -> NAME = exp1,exp1[,exp1] forbody */
|
|
|
1308 FuncState *fs = ls->fs;
|
|
|
1309 int base = fs->freereg;
|
|
|
1310 new_localvarliteral(ls, "(for index)");
|
|
|
1311 new_localvarliteral(ls, "(for limit)");
|
|
|
1312 new_localvarliteral(ls, "(for step)");
|
|
|
1313 new_localvar(ls, varname);
|
|
|
1314 checknext(ls, '=');
|
|
|
1315 exp1(ls); /* initial value */
|
|
|
1316 checknext(ls, ',');
|
|
|
1317 exp1(ls); /* limit */
|
|
|
1318 if (testnext(ls, ','))
|
|
|
1319 exp1(ls); /* optional step */
|
|
|
1320 else { /* default step = 1 */
|
|
|
1321 luaK_codek(fs, fs->freereg, luaK_numberK(fs, 1));
|
|
|
1322 luaK_reserveregs(fs, 1);
|
|
|
1323 }
|
|
|
1324 forbody(ls, base, line, 1, 1);
|
|
|
1325 }
|
|
|
1326
|
|
|
1327
|
|
|
1328 static void forlist (LexState *ls, TString *indexname) {
|
|
|
1329 /* forlist -> NAME {,NAME} IN explist forbody */
|
|
|
1330 FuncState *fs = ls->fs;
|
|
|
1331 expdesc e;
|
|
|
1332 int nvars = 4; /* gen, state, control, plus at least one declared var */
|
|
|
1333 int line;
|
|
|
1334 int base = fs->freereg;
|
|
|
1335 /* create control variables */
|
|
|
1336 new_localvarliteral(ls, "(for generator)");
|
|
|
1337 new_localvarliteral(ls, "(for state)");
|
|
|
1338 new_localvarliteral(ls, "(for control)");
|
|
|
1339 /* create declared variables */
|
|
|
1340 new_localvar(ls, indexname);
|
|
|
1341 while (testnext(ls, ',')) {
|
|
|
1342 new_localvar(ls, str_checkname(ls));
|
|
|
1343 nvars++;
|
|
|
1344 }
|
|
|
1345 checknext(ls, TK_IN);
|
|
|
1346 line = ls->linenumber;
|
|
|
1347 adjust_assign(ls, 3, explist(ls, &e), &e);
|
|
|
1348 luaK_checkstack(fs, 3); /* extra space to call generator */
|
|
|
1349 forbody(ls, base, line, nvars - 3, 0);
|
|
|
1350 }
|
|
|
1351
|
|
|
1352
|
|
|
1353 static void forstat (LexState *ls, int line) {
|
|
|
1354 /* forstat -> FOR (fornum | forlist) END */
|
|
|
1355 FuncState *fs = ls->fs;
|
|
|
1356 TString *varname;
|
|
|
1357 BlockCnt bl;
|
|
|
1358 enterblock(fs, &bl, 1); /* scope for loop and control variables */
|
|
|
1359 luaX_next(ls); /* skip `for' */
|
|
|
1360 varname = str_checkname(ls); /* first variable name */
|
|
|
1361 switch (ls->t.token) {
|
|
|
1362 case '=': fornum(ls, varname, line); break;
|
|
|
1363 case ',': case TK_IN: forlist(ls, varname); break;
|
|
|
1364 default: luaX_syntaxerror(ls, LUA_QL("=") " or " LUA_QL("in") " expected");
|
|
|
1365 }
|
|
|
1366 check_match(ls, TK_END, TK_FOR, line);
|
|
|
1367 leaveblock(fs); /* loop scope (`break' jumps to this point) */
|
|
|
1368 }
|
|
|
1369
|
|
|
1370
|
|
|
1371 static void test_then_block (LexState *ls, int *escapelist) {
|
|
|
1372 /* test_then_block -> [IF | ELSEIF] cond THEN block */
|
|
|
1373 BlockCnt bl;
|
|
|
1374 FuncState *fs = ls->fs;
|
|
|
1375 expdesc v;
|
|
|
1376 int jf; /* instruction to skip 'then' code (if condition is false) */
|
|
|
1377 luaX_next(ls); /* skip IF or ELSEIF */
|
|
|
1378 expr(ls, &v); /* read condition */
|
|
|
1379 checknext(ls, TK_THEN);
|
|
|
1380 if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) {
|
|
|
1381 luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */
|
|
|
1382 enterblock(fs, &bl, 0); /* must enter block before 'goto' */
|
|
|
1383 gotostat(ls, v.t); /* handle goto/break */
|
|
|
1384 skipnoopstat(ls); /* skip other no-op statements */
|
|
|
1385 if (block_follow(ls, 0)) { /* 'goto' is the entire block? */
|
|
|
1386 leaveblock(fs);
|
|
|
1387 return; /* and that is it */
|
|
|
1388 }
|
|
|
1389 else /* must skip over 'then' part if condition is false */
|
|
|
1390 jf = luaK_jump(fs);
|
|
|
1391 }
|
|
|
1392 else { /* regular case (not goto/break) */
|
|
|
1393 luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */
|
|
|
1394 enterblock(fs, &bl, 0);
|
|
|
1395 jf = v.f;
|
|
|
1396 }
|
|
|
1397 statlist(ls); /* `then' part */
|
|
|
1398 leaveblock(fs);
|
|
|
1399 if (ls->t.token == TK_ELSE ||
|
|
|
1400 ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */
|
|
|
1401 luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */
|
|
|
1402 luaK_patchtohere(fs, jf);
|
|
|
1403 }
|
|
|
1404
|
|
|
1405
|
|
|
1406 static void ifstat (LexState *ls, int line) {
|
|
|
1407 /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
|
|
|
1408 FuncState *fs = ls->fs;
|
|
|
1409 int escapelist = NO_JUMP; /* exit list for finished parts */
|
|
|
1410 test_then_block(ls, &escapelist); /* IF cond THEN block */
|
|
|
1411 while (ls->t.token == TK_ELSEIF)
|
|
|
1412 test_then_block(ls, &escapelist); /* ELSEIF cond THEN block */
|
|
|
1413 if (testnext(ls, TK_ELSE))
|
|
|
1414 block(ls); /* `else' part */
|
|
|
1415 check_match(ls, TK_END, TK_IF, line);
|
|
|
1416 luaK_patchtohere(fs, escapelist); /* patch escape list to 'if' end */
|
|
|
1417 }
|
|
|
1418
|
|
|
1419
|
|
|
1420 static void localfunc (LexState *ls) {
|
|
|
1421 expdesc b;
|
|
|
1422 FuncState *fs = ls->fs;
|
|
|
1423 new_localvar(ls, str_checkname(ls)); /* new local variable */
|
|
|
1424 adjustlocalvars(ls, 1); /* enter its scope */
|
|
|
1425 body(ls, &b, 0, ls->linenumber); /* function created in next register */
|
|
|
1426 /* debug information will only see the variable after this point! */
|
|
|
1427 getlocvar(fs, b.u.info)->startpc = fs->pc;
|
|
|
1428 }
|
|
|
1429
|
|
|
1430
|
|
|
1431 static void localstat (LexState *ls) {
|
|
|
1432 /* stat -> LOCAL NAME {`,' NAME} [`=' explist] */
|
|
|
1433 int nvars = 0;
|
|
|
1434 int nexps;
|
|
|
1435 expdesc e;
|
|
|
1436 do {
|
|
|
1437 new_localvar(ls, str_checkname(ls));
|
|
|
1438 nvars++;
|
|
|
1439 } while (testnext(ls, ','));
|
|
|
1440 if (testnext(ls, '='))
|
|
|
1441 nexps = explist(ls, &e);
|
|
|
1442 else {
|
|
|
1443 e.k = VVOID;
|
|
|
1444 nexps = 0;
|
|
|
1445 }
|
|
|
1446 adjust_assign(ls, nvars, nexps, &e);
|
|
|
1447 adjustlocalvars(ls, nvars);
|
|
|
1448 }
|
|
|
1449
|
|
|
1450
|
|
|
1451 static int funcname (LexState *ls, expdesc *v) {
|
|
|
1452 /* funcname -> NAME {fieldsel} [`:' NAME] */
|
|
|
1453 int ismethod = 0;
|
|
|
1454 singlevar(ls, v);
|
|
|
1455 while (ls->t.token == '.')
|
|
|
1456 fieldsel(ls, v);
|
|
|
1457 if (ls->t.token == ':') {
|
|
|
1458 ismethod = 1;
|
|
|
1459 fieldsel(ls, v);
|
|
|
1460 }
|
|
|
1461 return ismethod;
|
|
|
1462 }
|
|
|
1463
|
|
|
1464
|
|
|
1465 static void funcstat (LexState *ls, int line) {
|
|
|
1466 /* funcstat -> FUNCTION funcname body */
|
|
|
1467 int ismethod;
|
|
|
1468 expdesc v, b;
|
|
|
1469 luaX_next(ls); /* skip FUNCTION */
|
|
|
1470 ismethod = funcname(ls, &v);
|
|
|
1471 body(ls, &b, ismethod, line);
|
|
|
1472 luaK_storevar(ls->fs, &v, &b);
|
|
|
1473 luaK_fixline(ls->fs, line); /* definition `happens' in the first line */
|
|
|
1474 }
|
|
|
1475
|
|
|
1476
|
|
|
1477 static void exprstat (LexState *ls) {
|
|
|
1478 /* stat -> func | assignment */
|
|
|
1479 FuncState *fs = ls->fs;
|
|
|
1480 struct LHS_assign v;
|
|
|
1481 suffixedexp(ls, &v.v);
|
|
|
1482 if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */
|
|
|
1483 v.prev = NULL;
|
|
|
1484 assignment(ls, &v, 1);
|
|
|
1485 }
|
|
|
1486 else { /* stat -> func */
|
|
|
1487 check_condition(ls, v.v.k == VCALL, "syntax error");
|
|
|
1488 SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */
|
|
|
1489 }
|
|
|
1490 }
|
|
|
1491
|
|
|
1492
|
|
|
1493 static void retstat (LexState *ls) {
|
|
|
1494 /* stat -> RETURN [explist] [';'] */
|
|
|
1495 FuncState *fs = ls->fs;
|
|
|
1496 expdesc e;
|
|
|
1497 int first, nret; /* registers with returned values */
|
|
|
1498 if (block_follow(ls, 1) || ls->t.token == ';')
|
|
|
1499 first = nret = 0; /* return no values */
|
|
|
1500 else {
|
|
|
1501 nret = explist(ls, &e); /* optional return values */
|
|
|
1502 if (hasmultret(e.k)) {
|
|
|
1503 luaK_setmultret(fs, &e);
|
|
|
1504 if (e.k == VCALL && nret == 1) { /* tail call? */
|
|
|
1505 SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
|
|
|
1506 lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
|
|
|
1507 }
|
|
|
1508 first = fs->nactvar;
|
|
|
1509 nret = LUA_MULTRET; /* return all values */
|
|
|
1510 }
|
|
|
1511 else {
|
|
|
1512 if (nret == 1) /* only one single value? */
|
|
|
1513 first = luaK_exp2anyreg(fs, &e);
|
|
|
1514 else {
|
|
|
1515 luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */
|
|
|
1516 first = fs->nactvar; /* return all `active' values */
|
|
|
1517 lua_assert(nret == fs->freereg - first);
|
|
|
1518 }
|
|
|
1519 }
|
|
|
1520 }
|
|
|
1521 luaK_ret(fs, first, nret);
|
|
|
1522 testnext(ls, ';'); /* skip optional semicolon */
|
|
|
1523 }
|
|
|
1524
|
|
|
1525
|
|
|
1526 static void statement (LexState *ls) {
|
|
|
1527 int line = ls->linenumber; /* may be needed for error messages */
|
|
|
1528 enterlevel(ls);
|
|
|
1529 switch (ls->t.token) {
|
|
|
1530 case ';': { /* stat -> ';' (empty statement) */
|
|
|
1531 luaX_next(ls); /* skip ';' */
|
|
|
1532 break;
|
|
|
1533 }
|
|
|
1534 case TK_IF: { /* stat -> ifstat */
|
|
|
1535 ifstat(ls, line);
|
|
|
1536 break;
|
|
|
1537 }
|
|
|
1538 case TK_WHILE: { /* stat -> whilestat */
|
|
|
1539 whilestat(ls, line);
|
|
|
1540 break;
|
|
|
1541 }
|
|
|
1542 case TK_DO: { /* stat -> DO block END */
|
|
|
1543 luaX_next(ls); /* skip DO */
|
|
|
1544 block(ls);
|
|
|
1545 check_match(ls, TK_END, TK_DO, line);
|
|
|
1546 break;
|
|
|
1547 }
|
|
|
1548 case TK_FOR: { /* stat -> forstat */
|
|
|
1549 forstat(ls, line);
|
|
|
1550 break;
|
|
|
1551 }
|
|
|
1552 case TK_REPEAT: { /* stat -> repeatstat */
|
|
|
1553 repeatstat(ls, line);
|
|
|
1554 break;
|
|
|
1555 }
|
|
|
1556 case TK_FUNCTION: { /* stat -> funcstat */
|
|
|
1557 funcstat(ls, line);
|
|
|
1558 break;
|
|
|
1559 }
|
|
|
1560 case TK_LOCAL: { /* stat -> localstat */
|
|
|
1561 luaX_next(ls); /* skip LOCAL */
|
|
|
1562 if (testnext(ls, TK_FUNCTION)) /* local function? */
|
|
|
1563 localfunc(ls);
|
|
|
1564 else
|
|
|
1565 localstat(ls);
|
|
|
1566 break;
|
|
|
1567 }
|
|
|
1568 case TK_DBCOLON: { /* stat -> label */
|
|
|
1569 luaX_next(ls); /* skip double colon */
|
|
|
1570 labelstat(ls, str_checkname(ls), line);
|
|
|
1571 break;
|
|
|
1572 }
|
|
|
1573 case TK_RETURN: { /* stat -> retstat */
|
|
|
1574 luaX_next(ls); /* skip RETURN */
|
|
|
1575 retstat(ls);
|
|
|
1576 break;
|
|
|
1577 }
|
|
|
1578 case TK_BREAK: /* stat -> breakstat */
|
|
|
1579 case TK_GOTO: { /* stat -> 'goto' NAME */
|
|
|
1580 gotostat(ls, luaK_jump(ls->fs));
|
|
|
1581 break;
|
|
|
1582 }
|
|
|
1583 default: { /* stat -> func | assignment */
|
|
|
1584 exprstat(ls);
|
|
|
1585 break;
|
|
|
1586 }
|
|
|
1587 }
|
|
|
1588 lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg &&
|
|
|
1589 ls->fs->freereg >= ls->fs->nactvar);
|
|
|
1590 ls->fs->freereg = ls->fs->nactvar; /* free registers */
|
|
|
1591 leavelevel(ls);
|
|
|
1592 }
|
|
|
1593
|
|
|
1594 /* }====================================================================== */
|
|
|
1595
|
|
|
1596
|
|
|
1597 /*
|
|
|
1598 ** compiles the main function, which is a regular vararg function with an
|
|
|
1599 ** upvalue named LUA_ENV
|
|
|
1600 */
|
|
|
1601 static void mainfunc (LexState *ls, FuncState *fs) {
|
|
|
1602 BlockCnt bl;
|
|
|
1603 expdesc v;
|
|
|
1604 open_func(ls, fs, &bl);
|
|
|
1605 fs->f->is_vararg = 1; /* main function is always vararg */
|
|
|
1606 init_exp(&v, VLOCAL, 0); /* create and... */
|
|
|
1607 newupvalue(fs, ls->envn, &v); /* ...set environment upvalue */
|
|
|
1608 luaX_next(ls); /* read first token */
|
|
|
1609 statlist(ls); /* parse main body */
|
|
|
1610 check(ls, TK_EOS);
|
|
|
1611 close_func(ls);
|
|
|
1612 }
|
|
|
1613
|
|
|
1614
|
|
|
1615 Closure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
|
|
|
1616 Dyndata *dyd, const char *name, int firstchar) {
|
|
|
1617 LexState lexstate;
|
|
|
1618 FuncState funcstate;
|
|
|
1619 Closure *cl = luaF_newLclosure(L, 1); /* create main closure */
|
|
|
1620 /* anchor closure (to avoid being collected) */
|
|
|
1621 setclLvalue(L, L->top, cl);
|
|
|
1622 incr_top(L);
|
|
|
1623 funcstate.f = cl->l.p = luaF_newproto(L);
|
|
|
1624 funcstate.f->source = luaS_new(L, name); /* create and anchor TString */
|
|
|
1625 lexstate.buff = buff;
|
|
|
1626 lexstate.dyd = dyd;
|
|
|
1627 dyd->actvar.n = dyd->gt.n = dyd->label.n = 0;
|
|
|
1628 luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar);
|
|
|
1629 mainfunc(&lexstate, &funcstate);
|
|
|
1630 lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs);
|
|
|
1631 /* all scopes should be correctly finished */
|
|
|
1632 lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0);
|
|
|
1633 return cl; /* it's on the stack too */
|
|
|
1634 }
|
|
|
1635
|
