1 | /* |
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2 | ** $Id: lparser.c,v 1.208a 2003/04/03 13:35:34 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 | |
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12 | #include "lua.h" |
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13 | |
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14 | #include "lcode.h" |
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15 | #include "ldebug.h" |
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16 | #include "lfunc.h" |
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17 | #include "llex.h" |
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18 | #include "lmem.h" |
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19 | #include "lobject.h" |
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20 | #include "lopcodes.h" |
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21 | #include "lparser.h" |
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22 | #include "lstate.h" |
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23 | #include "lstring.h" |
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24 | |
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25 | |
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26 | |
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27 | |
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28 | #define getlocvar(fs, i) ((fs)->f->locvars[(fs)->actvar[i]]) |
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29 | |
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30 | |
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31 | #define enterlevel(ls) if (++(ls)->nestlevel > LUA_MAXPARSERLEVEL) \ |
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32 | luaX_syntaxerror(ls, "too many syntax levels"); |
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33 | #define leavelevel(ls) ((ls)->nestlevel--) |
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34 | |
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35 | |
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36 | /* |
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37 | ** nodes for block list (list of active blocks) |
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38 | */ |
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39 | typedef struct BlockCnt { |
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40 | struct BlockCnt *previous; /* chain */ |
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41 | int breaklist; /* list of jumps out of this loop */ |
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42 | int nactvar; /* # active local variables outside the breakable structure */ |
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43 | int upval; /* true if some variable in the block is an upvalue */ |
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44 | int isbreakable; /* true if `block' is a loop */ |
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45 | } BlockCnt; |
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46 | |
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47 | |
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48 | |
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49 | /* |
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50 | ** prototypes for recursive non-terminal functions |
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51 | */ |
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52 | static void chunk (LexState *ls); |
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53 | static void expr (LexState *ls, expdesc *v); |
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54 | |
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55 | |
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56 | |
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57 | static void next (LexState *ls) { |
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58 | ls->lastline = ls->linenumber; |
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59 | if (ls->lookahead.token != TK_EOS) { /* is there a look-ahead token? */ |
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60 | ls->t = ls->lookahead; /* use this one */ |
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61 | ls->lookahead.token = TK_EOS; /* and discharge it */ |
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62 | } |
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63 | else |
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64 | ls->t.token = luaX_lex(ls, &ls->t.seminfo); /* read next token */ |
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65 | } |
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66 | |
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67 | |
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68 | static void lookahead (LexState *ls) { |
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69 | lua_assert(ls->lookahead.token == TK_EOS); |
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70 | ls->lookahead.token = luaX_lex(ls, &ls->lookahead.seminfo); |
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71 | } |
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72 | |
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73 | |
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74 | static void error_expected (LexState *ls, int token) { |
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75 | luaX_syntaxerror(ls, |
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76 | luaO_pushfstring(ls->L, "`%s' expected", luaX_token2str(ls, token))); |
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77 | } |
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78 | |
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79 | |
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80 | static int testnext (LexState *ls, int c) { |
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81 | if (ls->t.token == c) { |
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82 | next(ls); |
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83 | return 1; |
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84 | } |
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85 | else return 0; |
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86 | } |
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87 | |
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88 | |
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89 | static void check (LexState *ls, int c) { |
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90 | if (!testnext(ls, c)) |
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91 | error_expected(ls, c); |
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92 | } |
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93 | |
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94 | |
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95 | #define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); } |
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96 | |
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97 | |
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98 | |
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99 | static void check_match (LexState *ls, int what, int who, int where) { |
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100 | if (!testnext(ls, what)) { |
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101 | if (where == ls->linenumber) |
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102 | error_expected(ls, what); |
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103 | else { |
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104 | luaX_syntaxerror(ls, luaO_pushfstring(ls->L, |
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105 | "`%s' expected (to close `%s' at line %d)", |
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106 | luaX_token2str(ls, what), luaX_token2str(ls, who), where)); |
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107 | } |
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108 | } |
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109 | } |
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110 | |
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111 | |
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112 | static TString *str_checkname (LexState *ls) { |
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113 | TString *ts; |
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114 | check_condition(ls, (ls->t.token == TK_NAME), "<name> expected"); |
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115 | ts = ls->t.seminfo.ts; |
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116 | next(ls); |
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117 | return ts; |
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118 | } |
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119 | |
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120 | |
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121 | static void init_exp (expdesc *e, expkind k, int i) { |
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122 | e->f = e->t = NO_JUMP; |
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123 | e->k = k; |
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124 | e->info = i; |
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125 | } |
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126 | |
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127 | |
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128 | static void codestring (LexState *ls, expdesc *e, TString *s) { |
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129 | init_exp(e, VK, luaK_stringK(ls->fs, s)); |
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130 | } |
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131 | |
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132 | |
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133 | static void checkname(LexState *ls, expdesc *e) { |
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134 | codestring(ls, e, str_checkname(ls)); |
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135 | } |
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136 | |
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137 | |
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138 | static int luaI_registerlocalvar (LexState *ls, TString *varname) { |
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139 | FuncState *fs = ls->fs; |
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140 | Proto *f = fs->f; |
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141 | luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars, |
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142 | LocVar, MAX_INT, ""); |
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143 | f->locvars[fs->nlocvars].varname = varname; |
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144 | return fs->nlocvars++; |
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145 | } |
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146 | |
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147 | |
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148 | static void new_localvar (LexState *ls, TString *name, int n) { |
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149 | FuncState *fs = ls->fs; |
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150 | luaX_checklimit(ls, fs->nactvar+n+1, MAXVARS, "local variables"); |
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151 | fs->actvar[fs->nactvar+n] = luaI_registerlocalvar(ls, name); |
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152 | } |
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153 | |
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154 | |
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155 | static void adjustlocalvars (LexState *ls, int nvars) { |
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156 | FuncState *fs = ls->fs; |
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157 | fs->nactvar += nvars; |
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158 | for (; nvars; nvars--) { |
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159 | getlocvar(fs, fs->nactvar - nvars).startpc = fs->pc; |
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160 | } |
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161 | } |
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162 | |
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163 | |
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164 | static void removevars (LexState *ls, int tolevel) { |
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165 | FuncState *fs = ls->fs; |
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166 | while (fs->nactvar > tolevel) |
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167 | getlocvar(fs, --fs->nactvar).endpc = fs->pc; |
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168 | } |
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169 | |
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170 | |
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171 | static void new_localvarstr (LexState *ls, const char *name, int n) { |
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172 | new_localvar(ls, luaS_new(ls->L, name), n); |
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173 | } |
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174 | |
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175 | |
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176 | static void create_local (LexState *ls, const char *name) { |
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177 | new_localvarstr(ls, name, 0); |
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178 | adjustlocalvars(ls, 1); |
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179 | } |
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180 | |
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181 | |
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182 | static int indexupvalue (FuncState *fs, TString *name, expdesc *v) { |
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183 | int i; |
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184 | Proto *f = fs->f; |
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185 | for (i=0; i<f->nups; i++) { |
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186 | if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->info) { |
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187 | lua_assert(fs->f->upvalues[i] == name); |
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188 | return i; |
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189 | } |
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190 | } |
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191 | /* new one */ |
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192 | luaX_checklimit(fs->ls, f->nups + 1, MAXUPVALUES, "upvalues"); |
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193 | luaM_growvector(fs->L, fs->f->upvalues, f->nups, fs->f->sizeupvalues, |
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194 | TString *, MAX_INT, ""); |
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195 | fs->f->upvalues[f->nups] = name; |
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196 | fs->upvalues[f->nups] = *v; |
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197 | return f->nups++; |
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198 | } |
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199 | |
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200 | |
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201 | static int searchvar (FuncState *fs, TString *n) { |
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202 | int i; |
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203 | for (i=fs->nactvar-1; i >= 0; i--) { |
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204 | if (n == getlocvar(fs, i).varname) |
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205 | return i; |
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206 | } |
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207 | return -1; /* not found */ |
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208 | } |
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209 | |
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210 | |
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211 | static void markupval (FuncState *fs, int level) { |
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212 | BlockCnt *bl = fs->bl; |
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213 | while (bl && bl->nactvar > level) bl = bl->previous; |
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214 | if (bl) bl->upval = 1; |
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215 | } |
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216 | |
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217 | |
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218 | static void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) { |
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219 | if (fs == NULL) /* no more levels? */ |
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220 | init_exp(var, VGLOBAL, NO_REG); /* default is global variable */ |
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221 | else { |
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222 | int v = searchvar(fs, n); /* look up at current level */ |
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223 | if (v >= 0) { |
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224 | init_exp(var, VLOCAL, v); |
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225 | if (!base) |
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226 | markupval(fs, v); /* local will be used as an upval */ |
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227 | } |
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228 | else { /* not found at current level; try upper one */ |
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229 | singlevaraux(fs->prev, n, var, 0); |
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230 | if (var->k == VGLOBAL) { |
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231 | if (base) |
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232 | var->info = luaK_stringK(fs, n); /* info points to global name */ |
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233 | } |
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234 | else { /* LOCAL or UPVAL */ |
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235 | var->info = indexupvalue(fs, n, var); |
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236 | var->k = VUPVAL; /* upvalue in this level */ |
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237 | } |
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238 | } |
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239 | } |
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240 | } |
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241 | |
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242 | |
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243 | static TString *singlevar (LexState *ls, expdesc *var, int base) { |
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244 | TString *varname = str_checkname(ls); |
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245 | singlevaraux(ls->fs, varname, var, base); |
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246 | return varname; |
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247 | } |
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248 | |
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249 | |
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250 | static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) { |
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251 | FuncState *fs = ls->fs; |
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252 | int extra = nvars - nexps; |
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253 | if (e->k == VCALL) { |
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254 | extra++; /* includes call itself */ |
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255 | if (extra <= 0) extra = 0; |
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256 | else luaK_reserveregs(fs, extra-1); |
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257 | luaK_setcallreturns(fs, e, extra); /* call provides the difference */ |
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258 | } |
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259 | else { |
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260 | if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */ |
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261 | if (extra > 0) { |
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262 | int reg = fs->freereg; |
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263 | luaK_reserveregs(fs, extra); |
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264 | luaK_nil(fs, reg, extra); |
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265 | } |
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266 | } |
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267 | } |
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268 | |
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269 | |
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270 | static void code_params (LexState *ls, int nparams, int dots) { |
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271 | FuncState *fs = ls->fs; |
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272 | adjustlocalvars(ls, nparams); |
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273 | luaX_checklimit(ls, fs->nactvar, MAXPARAMS, "parameters"); |
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274 | fs->f->numparams = cast(lu_byte, fs->nactvar); |
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275 | fs->f->is_vararg = cast(lu_byte, dots); |
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276 | if (dots) |
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277 | create_local(ls, "arg"); |
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278 | luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */ |
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279 | } |
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280 | |
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281 | |
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282 | static void enterblock (FuncState *fs, BlockCnt *bl, int isbreakable) { |
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283 | bl->breaklist = NO_JUMP; |
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284 | bl->isbreakable = isbreakable; |
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285 | bl->nactvar = fs->nactvar; |
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286 | bl->upval = 0; |
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287 | bl->previous = fs->bl; |
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288 | fs->bl = bl; |
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289 | lua_assert(fs->freereg == fs->nactvar); |
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290 | } |
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291 | |
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292 | |
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293 | static void leaveblock (FuncState *fs) { |
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294 | BlockCnt *bl = fs->bl; |
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295 | fs->bl = bl->previous; |
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296 | removevars(fs->ls, bl->nactvar); |
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297 | if (bl->upval) |
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298 | luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0); |
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299 | lua_assert(bl->nactvar == fs->nactvar); |
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300 | fs->freereg = fs->nactvar; /* free registers */ |
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301 | luaK_patchtohere(fs, bl->breaklist); |
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302 | } |
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303 | |
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304 | |
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305 | static void pushclosure (LexState *ls, FuncState *func, expdesc *v) { |
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306 | FuncState *fs = ls->fs; |
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307 | Proto *f = fs->f; |
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308 | int i; |
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309 | luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *, |
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310 | MAXARG_Bx, "constant table overflow"); |
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311 | f->p[fs->np++] = func->f; |
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312 | init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1)); |
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313 | for (i=0; i<func->f->nups; i++) { |
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314 | OpCode o = (func->upvalues[i].k == VLOCAL) ? OP_MOVE : OP_GETUPVAL; |
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315 | luaK_codeABC(fs, o, 0, func->upvalues[i].info, 0); |
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316 | } |
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317 | } |
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318 | |
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319 | |
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320 | static void open_func (LexState *ls, FuncState *fs) { |
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321 | Proto *f = luaF_newproto(ls->L); |
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322 | fs->f = f; |
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323 | fs->prev = ls->fs; /* linked list of funcstates */ |
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324 | fs->ls = ls; |
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325 | fs->L = ls->L; |
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326 | ls->fs = fs; |
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327 | fs->pc = 0; |
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328 | fs->lasttarget = 0; |
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329 | fs->jpc = NO_JUMP; |
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330 | fs->freereg = 0; |
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331 | fs->nk = 0; |
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332 | fs->h = luaH_new(ls->L, 0, 0); |
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333 | fs->np = 0; |
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334 | fs->nlocvars = 0; |
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335 | fs->nactvar = 0; |
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336 | fs->bl = NULL; |
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337 | f->source = ls->source; |
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338 | f->maxstacksize = 2; /* registers 0/1 are always valid */ |
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339 | } |
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340 | |
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341 | |
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342 | static void close_func (LexState *ls) { |
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343 | lua_State *L = ls->L; |
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344 | FuncState *fs = ls->fs; |
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345 | Proto *f = fs->f; |
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346 | removevars(ls, 0); |
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347 | luaK_codeABC(fs, OP_RETURN, 0, 1, 0); /* final return */ |
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348 | luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction); |
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349 | f->sizecode = fs->pc; |
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350 | luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int); |
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351 | f->sizelineinfo = fs->pc; |
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352 | luaM_reallocvector(L, f->k, f->sizek, fs->nk, TObject); |
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353 | f->sizek = fs->nk; |
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354 | luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *); |
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355 | f->sizep = fs->np; |
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356 | luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar); |
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357 | f->sizelocvars = fs->nlocvars; |
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358 | luaM_reallocvector(L, f->upvalues, f->sizeupvalues, f->nups, TString *); |
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359 | f->sizeupvalues = f->nups; |
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360 | lua_assert(luaG_checkcode(f)); |
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361 | lua_assert(fs->bl == NULL); |
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362 | ls->fs = fs->prev; |
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363 | } |
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364 | |
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365 | |
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366 | Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff) { |
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367 | struct LexState lexstate; |
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368 | struct FuncState funcstate; |
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369 | lexstate.buff = buff; |
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370 | lexstate.nestlevel = 0; |
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371 | luaX_setinput(L, &lexstate, z, luaS_new(L, zname(z))); |
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372 | open_func(&lexstate, &funcstate); |
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373 | next(&lexstate); /* read first token */ |
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374 | chunk(&lexstate); |
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375 | check_condition(&lexstate, (lexstate.t.token == TK_EOS), "<eof> expected"); |
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376 | close_func(&lexstate); |
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377 | lua_assert(funcstate.prev == NULL); |
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378 | lua_assert(funcstate.f->nups == 0); |
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379 | lua_assert(lexstate.nestlevel == 0); |
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380 | return funcstate.f; |
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381 | } |
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382 | |
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383 | |
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384 | |
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385 | /*============================================================*/ |
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386 | /* GRAMMAR RULES */ |
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387 | /*============================================================*/ |
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388 | |
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389 | |
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390 | static void luaY_field (LexState *ls, expdesc *v) { |
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391 | /* field -> ['.' | ':'] NAME */ |
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392 | FuncState *fs = ls->fs; |
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393 | expdesc key; |
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394 | luaK_exp2anyreg(fs, v); |
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395 | next(ls); /* skip the dot or colon */ |
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396 | checkname(ls, &key); |
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397 | luaK_indexed(fs, v, &key); |
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398 | } |
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399 | |
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400 | |
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401 | static void luaY_index (LexState *ls, expdesc *v) { |
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402 | /* index -> '[' expr ']' */ |
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403 | next(ls); /* skip the '[' */ |
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404 | expr(ls, v); |
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405 | luaK_exp2val(ls->fs, v); |
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406 | check(ls, ']'); |
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407 | } |
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408 | |
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409 | |
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410 | /* |
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411 | ** {====================================================================== |
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412 | ** Rules for Constructors |
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413 | ** ======================================================================= |
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414 | */ |
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415 | |
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416 | |
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417 | struct ConsControl { |
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418 | expdesc v; /* last list item read */ |
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419 | expdesc *t; /* table descriptor */ |
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420 | int nh; /* total number of `record' elements */ |
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421 | int na; /* total number of array elements */ |
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422 | int tostore; /* number of array elements pending to be stored */ |
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423 | }; |
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424 | |
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425 | |
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426 | static void recfield (LexState *ls, struct ConsControl *cc) { |
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427 | /* recfield -> (NAME | `['exp1`]') = exp1 */ |
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428 | FuncState *fs = ls->fs; |
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429 | int reg = ls->fs->freereg; |
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430 | expdesc key, val; |
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431 | if (ls->t.token == TK_NAME) { |
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432 | luaX_checklimit(ls, cc->nh, MAX_INT, "items in a constructor"); |
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433 | cc->nh++; |
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434 | checkname(ls, &key); |
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435 | } |
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436 | else /* ls->t.token == '[' */ |
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437 | luaY_index(ls, &key); |
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438 | check(ls, '='); |
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439 | luaK_exp2RK(fs, &key); |
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440 | expr(ls, &val); |
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441 | luaK_codeABC(fs, OP_SETTABLE, cc->t->info, luaK_exp2RK(fs, &key), |
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442 | luaK_exp2RK(fs, &val)); |
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443 | fs->freereg = reg; /* free registers */ |
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444 | } |
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445 | |
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446 | |
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447 | static void closelistfield (FuncState *fs, struct ConsControl *cc) { |
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448 | if (cc->v.k == VVOID) return; /* there is no list item */ |
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449 | luaK_exp2nextreg(fs, &cc->v); |
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450 | cc->v.k = VVOID; |
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451 | if (cc->tostore == LFIELDS_PER_FLUSH) { |
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452 | luaK_codeABx(fs, OP_SETLIST, cc->t->info, cc->na-1); /* flush */ |
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453 | cc->tostore = 0; /* no more items pending */ |
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454 | fs->freereg = cc->t->info + 1; /* free registers */ |
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455 | } |
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456 | } |
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457 | |
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458 | |
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459 | static void lastlistfield (FuncState *fs, struct ConsControl *cc) { |
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460 | if (cc->tostore == 0) return; |
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461 | if (cc->v.k == VCALL) { |
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462 | luaK_setcallreturns(fs, &cc->v, LUA_MULTRET); |
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463 | luaK_codeABx(fs, OP_SETLISTO, cc->t->info, cc->na-1); |
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464 | } |
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465 | else { |
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466 | if (cc->v.k != VVOID) |
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467 | luaK_exp2nextreg(fs, &cc->v); |
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468 | luaK_codeABx(fs, OP_SETLIST, cc->t->info, cc->na-1); |
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469 | } |
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470 | fs->freereg = cc->t->info + 1; /* free registers */ |
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471 | } |
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472 | |
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473 | |
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474 | static void listfield (LexState *ls, struct ConsControl *cc) { |
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475 | expr(ls, &cc->v); |
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476 | luaX_checklimit(ls, cc->na, MAXARG_Bx, "items in a constructor"); |
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477 | cc->na++; |
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478 | cc->tostore++; |
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479 | } |
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480 | |
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481 | |
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482 | static void constructor (LexState *ls, expdesc *t) { |
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483 | /* constructor -> ?? */ |
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484 | FuncState *fs = ls->fs; |
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485 | int line = ls->linenumber; |
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486 | int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0); |
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487 | struct ConsControl cc; |
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488 | cc.na = cc.nh = cc.tostore = 0; |
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489 | cc.t = t; |
---|
490 | init_exp(t, VRELOCABLE, pc); |
---|
491 | init_exp(&cc.v, VVOID, 0); /* no value (yet) */ |
---|
492 | luaK_exp2nextreg(ls->fs, t); /* fix it at stack top (for gc) */ |
---|
493 | check(ls, '{'); |
---|
494 | do { |
---|
495 | lua_assert(cc.v.k == VVOID || cc.tostore > 0); |
---|
496 | testnext(ls, ';'); /* compatibility only */ |
---|
497 | if (ls->t.token == '}') break; |
---|
498 | closelistfield(fs, &cc); |
---|
499 | switch(ls->t.token) { |
---|
500 | case TK_NAME: { /* may be listfields or recfields */ |
---|
501 | lookahead(ls); |
---|
502 | if (ls->lookahead.token != '=') /* expression? */ |
---|
503 | listfield(ls, &cc); |
---|
504 | else |
---|
505 | recfield(ls, &cc); |
---|
506 | break; |
---|
507 | } |
---|
508 | case '[': { /* constructor_item -> recfield */ |
---|
509 | recfield(ls, &cc); |
---|
510 | break; |
---|
511 | } |
---|
512 | default: { /* constructor_part -> listfield */ |
---|
513 | listfield(ls, &cc); |
---|
514 | break; |
---|
515 | } |
---|
516 | } |
---|
517 | } while (testnext(ls, ',') || testnext(ls, ';')); |
---|
518 | check_match(ls, '}', '{', line); |
---|
519 | lastlistfield(fs, &cc); |
---|
520 | SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */ |
---|
521 | SETARG_C(fs->f->code[pc], luaO_log2(cc.nh)+1); /* set initial table size */ |
---|
522 | } |
---|
523 | |
---|
524 | /* }====================================================================== */ |
---|
525 | |
---|
526 | |
---|
527 | |
---|
528 | static void parlist (LexState *ls) { |
---|
529 | /* parlist -> [ param { `,' param } ] */ |
---|
530 | int nparams = 0; |
---|
531 | int dots = 0; |
---|
532 | if (ls->t.token != ')') { /* is `parlist' not empty? */ |
---|
533 | do { |
---|
534 | switch (ls->t.token) { |
---|
535 | case TK_DOTS: dots = 1; next(ls); break; |
---|
536 | case TK_NAME: new_localvar(ls, str_checkname(ls), nparams++); break; |
---|
537 | default: luaX_syntaxerror(ls, "<name> or `...' expected"); |
---|
538 | } |
---|
539 | } while (!dots && testnext(ls, ',')); |
---|
540 | } |
---|
541 | code_params(ls, nparams, dots); |
---|
542 | } |
---|
543 | |
---|
544 | |
---|
545 | static void body (LexState *ls, expdesc *e, int needself, int line) { |
---|
546 | /* body -> `(' parlist `)' chunk END */ |
---|
547 | FuncState new_fs; |
---|
548 | open_func(ls, &new_fs); |
---|
549 | new_fs.f->lineDefined = line; |
---|
550 | check(ls, '('); |
---|
551 | if (needself) |
---|
552 | create_local(ls, "self"); |
---|
553 | parlist(ls); |
---|
554 | check(ls, ')'); |
---|
555 | chunk(ls); |
---|
556 | check_match(ls, TK_END, TK_FUNCTION, line); |
---|
557 | close_func(ls); |
---|
558 | pushclosure(ls, &new_fs, e); |
---|
559 | } |
---|
560 | |
---|
561 | |
---|
562 | static int explist1 (LexState *ls, expdesc *v) { |
---|
563 | /* explist1 -> expr { `,' expr } */ |
---|
564 | int n = 1; /* at least one expression */ |
---|
565 | expr(ls, v); |
---|
566 | while (testnext(ls, ',')) { |
---|
567 | luaK_exp2nextreg(ls->fs, v); |
---|
568 | expr(ls, v); |
---|
569 | n++; |
---|
570 | } |
---|
571 | return n; |
---|
572 | } |
---|
573 | |
---|
574 | |
---|
575 | static void funcargs (LexState *ls, expdesc *f) { |
---|
576 | FuncState *fs = ls->fs; |
---|
577 | expdesc args; |
---|
578 | int base, nparams; |
---|
579 | int line = ls->linenumber; |
---|
580 | switch (ls->t.token) { |
---|
581 | case '(': { /* funcargs -> `(' [ explist1 ] `)' */ |
---|
582 | if (line != ls->lastline) |
---|
583 | luaX_syntaxerror(ls,"ambiguous syntax (function call x new statement)"); |
---|
584 | next(ls); |
---|
585 | if (ls->t.token == ')') /* arg list is empty? */ |
---|
586 | args.k = VVOID; |
---|
587 | else { |
---|
588 | explist1(ls, &args); |
---|
589 | luaK_setcallreturns(fs, &args, LUA_MULTRET); |
---|
590 | } |
---|
591 | check_match(ls, ')', '(', line); |
---|
592 | break; |
---|
593 | } |
---|
594 | case '{': { /* funcargs -> constructor */ |
---|
595 | constructor(ls, &args); |
---|
596 | break; |
---|
597 | } |
---|
598 | case TK_STRING: { /* funcargs -> STRING */ |
---|
599 | codestring(ls, &args, ls->t.seminfo.ts); |
---|
600 | next(ls); /* must use `seminfo' before `next' */ |
---|
601 | break; |
---|
602 | } |
---|
603 | default: { |
---|
604 | luaX_syntaxerror(ls, "function arguments expected"); |
---|
605 | return; |
---|
606 | } |
---|
607 | } |
---|
608 | lua_assert(f->k == VNONRELOC); |
---|
609 | base = f->info; /* base register for call */ |
---|
610 | if (args.k == VCALL) |
---|
611 | nparams = LUA_MULTRET; /* open call */ |
---|
612 | else { |
---|
613 | if (args.k != VVOID) |
---|
614 | luaK_exp2nextreg(fs, &args); /* close last argument */ |
---|
615 | nparams = fs->freereg - (base+1); |
---|
616 | } |
---|
617 | init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2)); |
---|
618 | luaK_fixline(fs, line); |
---|
619 | fs->freereg = base+1; /* call remove function and arguments and leaves |
---|
620 | (unless changed) one result */ |
---|
621 | } |
---|
622 | |
---|
623 | |
---|
624 | |
---|
625 | |
---|
626 | /* |
---|
627 | ** {====================================================================== |
---|
628 | ** Expression parsing |
---|
629 | ** ======================================================================= |
---|
630 | */ |
---|
631 | |
---|
632 | |
---|
633 | static void prefixexp (LexState *ls, expdesc *v) { |
---|
634 | /* prefixexp -> NAME | '(' expr ')' */ |
---|
635 | switch (ls->t.token) { |
---|
636 | case '(': { |
---|
637 | int line = ls->linenumber; |
---|
638 | next(ls); |
---|
639 | expr(ls, v); |
---|
640 | check_match(ls, ')', '(', line); |
---|
641 | luaK_dischargevars(ls->fs, v); |
---|
642 | return; |
---|
643 | } |
---|
644 | case TK_NAME: { |
---|
645 | singlevar(ls, v, 1); |
---|
646 | return; |
---|
647 | } |
---|
648 | #ifdef LUA_COMPATUPSYNTAX |
---|
649 | case '%': { /* for compatibility only */ |
---|
650 | TString *varname; |
---|
651 | int line = ls->linenumber; |
---|
652 | next(ls); /* skip `%' */ |
---|
653 | varname = singlevar(ls, v, 1); |
---|
654 | if (v->k != VUPVAL) |
---|
655 | luaX_errorline(ls, "global upvalues are obsolete", |
---|
656 | getstr(varname), line); |
---|
657 | return; |
---|
658 | } |
---|
659 | #endif |
---|
660 | default: { |
---|
661 | luaX_syntaxerror(ls, "unexpected symbol"); |
---|
662 | return; |
---|
663 | } |
---|
664 | } |
---|
665 | } |
---|
666 | |
---|
667 | |
---|
668 | static void primaryexp (LexState *ls, expdesc *v) { |
---|
669 | /* primaryexp -> |
---|
670 | prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */ |
---|
671 | FuncState *fs = ls->fs; |
---|
672 | prefixexp(ls, v); |
---|
673 | for (;;) { |
---|
674 | switch (ls->t.token) { |
---|
675 | case '.': { /* field */ |
---|
676 | luaY_field(ls, v); |
---|
677 | break; |
---|
678 | } |
---|
679 | case '[': { /* `[' exp1 `]' */ |
---|
680 | expdesc key; |
---|
681 | luaK_exp2anyreg(fs, v); |
---|
682 | luaY_index(ls, &key); |
---|
683 | luaK_indexed(fs, v, &key); |
---|
684 | break; |
---|
685 | } |
---|
686 | case ':': { /* `:' NAME funcargs */ |
---|
687 | expdesc key; |
---|
688 | next(ls); |
---|
689 | checkname(ls, &key); |
---|
690 | luaK_self(fs, v, &key); |
---|
691 | funcargs(ls, v); |
---|
692 | break; |
---|
693 | } |
---|
694 | case '(': case TK_STRING: case '{': { /* funcargs */ |
---|
695 | luaK_exp2nextreg(fs, v); |
---|
696 | funcargs(ls, v); |
---|
697 | break; |
---|
698 | } |
---|
699 | default: return; |
---|
700 | } |
---|
701 | } |
---|
702 | } |
---|
703 | |
---|
704 | |
---|
705 | static void simpleexp (LexState *ls, expdesc *v) { |
---|
706 | /* simpleexp -> NUMBER | STRING | NIL | constructor | FUNCTION body |
---|
707 | | primaryexp */ |
---|
708 | switch (ls->t.token) { |
---|
709 | case TK_NUMBER: { |
---|
710 | init_exp(v, VK, luaK_numberK(ls->fs, ls->t.seminfo.r)); |
---|
711 | next(ls); /* must use `seminfo' before `next' */ |
---|
712 | break; |
---|
713 | } |
---|
714 | case TK_STRING: { |
---|
715 | codestring(ls, v, ls->t.seminfo.ts); |
---|
716 | next(ls); /* must use `seminfo' before `next' */ |
---|
717 | break; |
---|
718 | } |
---|
719 | case TK_NIL: { |
---|
720 | init_exp(v, VNIL, 0); |
---|
721 | next(ls); |
---|
722 | break; |
---|
723 | } |
---|
724 | case TK_TRUE: { |
---|
725 | init_exp(v, VTRUE, 0); |
---|
726 | next(ls); |
---|
727 | break; |
---|
728 | } |
---|
729 | case TK_FALSE: { |
---|
730 | init_exp(v, VFALSE, 0); |
---|
731 | next(ls); |
---|
732 | break; |
---|
733 | } |
---|
734 | case '{': { /* constructor */ |
---|
735 | constructor(ls, v); |
---|
736 | break; |
---|
737 | } |
---|
738 | case TK_FUNCTION: { |
---|
739 | next(ls); |
---|
740 | body(ls, v, 0, ls->linenumber); |
---|
741 | break; |
---|
742 | } |
---|
743 | default: { |
---|
744 | primaryexp(ls, v); |
---|
745 | break; |
---|
746 | } |
---|
747 | } |
---|
748 | } |
---|
749 | |
---|
750 | |
---|
751 | static UnOpr getunopr (int op) { |
---|
752 | switch (op) { |
---|
753 | case TK_NOT: return OPR_NOT; |
---|
754 | case '-': return OPR_MINUS; |
---|
755 | default: return OPR_NOUNOPR; |
---|
756 | } |
---|
757 | } |
---|
758 | |
---|
759 | |
---|
760 | static BinOpr getbinopr (int op) { |
---|
761 | switch (op) { |
---|
762 | case '+': return OPR_ADD; |
---|
763 | case '-': return OPR_SUB; |
---|
764 | case '*': return OPR_MULT; |
---|
765 | case '/': return OPR_DIV; |
---|
766 | case '^': return OPR_POW; |
---|
767 | case TK_CONCAT: return OPR_CONCAT; |
---|
768 | case TK_NE: return OPR_NE; |
---|
769 | case TK_EQ: return OPR_EQ; |
---|
770 | case '<': return OPR_LT; |
---|
771 | case TK_LE: return OPR_LE; |
---|
772 | case '>': return OPR_GT; |
---|
773 | case TK_GE: return OPR_GE; |
---|
774 | case TK_AND: return OPR_AND; |
---|
775 | case TK_OR: return OPR_OR; |
---|
776 | default: return OPR_NOBINOPR; |
---|
777 | } |
---|
778 | } |
---|
779 | |
---|
780 | |
---|
781 | static const struct { |
---|
782 | lu_byte left; /* left priority for each binary operator */ |
---|
783 | lu_byte right; /* right priority */ |
---|
784 | } priority[] = { /* ORDER OPR */ |
---|
785 | {6, 6}, {6, 6}, {7, 7}, {7, 7}, /* arithmetic */ |
---|
786 | {10, 9}, {5, 4}, /* power and concat (right associative) */ |
---|
787 | {3, 3}, {3, 3}, /* equality */ |
---|
788 | {3, 3}, {3, 3}, {3, 3}, {3, 3}, /* order */ |
---|
789 | {2, 2}, {1, 1} /* logical (and/or) */ |
---|
790 | }; |
---|
791 | |
---|
792 | #define UNARY_PRIORITY 8 /* priority for unary operators */ |
---|
793 | |
---|
794 | |
---|
795 | /* |
---|
796 | ** subexpr -> (simplexep | unop subexpr) { binop subexpr } |
---|
797 | ** where `binop' is any binary operator with a priority higher than `limit' |
---|
798 | */ |
---|
799 | static BinOpr subexpr (LexState *ls, expdesc *v, int limit) { |
---|
800 | BinOpr op; |
---|
801 | UnOpr uop; |
---|
802 | enterlevel(ls); |
---|
803 | uop = getunopr(ls->t.token); |
---|
804 | if (uop != OPR_NOUNOPR) { |
---|
805 | next(ls); |
---|
806 | subexpr(ls, v, UNARY_PRIORITY); |
---|
807 | luaK_prefix(ls->fs, uop, v); |
---|
808 | } |
---|
809 | else simpleexp(ls, v); |
---|
810 | /* expand while operators have priorities higher than `limit' */ |
---|
811 | op = getbinopr(ls->t.token); |
---|
812 | while (op != OPR_NOBINOPR && cast(int, priority[op].left) > limit) { |
---|
813 | expdesc v2; |
---|
814 | BinOpr nextop; |
---|
815 | next(ls); |
---|
816 | luaK_infix(ls->fs, op, v); |
---|
817 | /* read sub-expression with higher priority */ |
---|
818 | nextop = subexpr(ls, &v2, cast(int, priority[op].right)); |
---|
819 | luaK_posfix(ls->fs, op, v, &v2); |
---|
820 | op = nextop; |
---|
821 | } |
---|
822 | leavelevel(ls); |
---|
823 | return op; /* return first untreated operator */ |
---|
824 | } |
---|
825 | |
---|
826 | |
---|
827 | static void expr (LexState *ls, expdesc *v) { |
---|
828 | subexpr(ls, v, -1); |
---|
829 | } |
---|
830 | |
---|
831 | /* }==================================================================== */ |
---|
832 | |
---|
833 | |
---|
834 | |
---|
835 | /* |
---|
836 | ** {====================================================================== |
---|
837 | ** Rules for Statements |
---|
838 | ** ======================================================================= |
---|
839 | */ |
---|
840 | |
---|
841 | |
---|
842 | static int block_follow (int token) { |
---|
843 | switch (token) { |
---|
844 | case TK_ELSE: case TK_ELSEIF: case TK_END: |
---|
845 | case TK_UNTIL: case TK_EOS: |
---|
846 | return 1; |
---|
847 | default: return 0; |
---|
848 | } |
---|
849 | } |
---|
850 | |
---|
851 | |
---|
852 | static void block (LexState *ls) { |
---|
853 | /* block -> chunk */ |
---|
854 | FuncState *fs = ls->fs; |
---|
855 | BlockCnt bl; |
---|
856 | enterblock(fs, &bl, 0); |
---|
857 | chunk(ls); |
---|
858 | lua_assert(bl.breaklist == NO_JUMP); |
---|
859 | leaveblock(fs); |
---|
860 | } |
---|
861 | |
---|
862 | |
---|
863 | /* |
---|
864 | ** structure to chain all variables in the left-hand side of an |
---|
865 | ** assignment |
---|
866 | */ |
---|
867 | struct LHS_assign { |
---|
868 | struct LHS_assign *prev; |
---|
869 | expdesc v; /* variable (global, local, upvalue, or indexed) */ |
---|
870 | }; |
---|
871 | |
---|
872 | |
---|
873 | /* |
---|
874 | ** check whether, in an assignment to a local variable, the local variable |
---|
875 | ** is needed in a previous assignment (to a table). If so, save original |
---|
876 | ** local value in a safe place and use this safe copy in the previous |
---|
877 | ** assignment. |
---|
878 | */ |
---|
879 | static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) { |
---|
880 | FuncState *fs = ls->fs; |
---|
881 | int extra = fs->freereg; /* eventual position to save local variable */ |
---|
882 | int conflict = 0; |
---|
883 | for (; lh; lh = lh->prev) { |
---|
884 | if (lh->v.k == VINDEXED) { |
---|
885 | if (lh->v.info == v->info) { /* conflict? */ |
---|
886 | conflict = 1; |
---|
887 | lh->v.info = extra; /* previous assignment will use safe copy */ |
---|
888 | } |
---|
889 | if (lh->v.aux == v->info) { /* conflict? */ |
---|
890 | conflict = 1; |
---|
891 | lh->v.aux = extra; /* previous assignment will use safe copy */ |
---|
892 | } |
---|
893 | } |
---|
894 | } |
---|
895 | if (conflict) { |
---|
896 | luaK_codeABC(fs, OP_MOVE, fs->freereg, v->info, 0); /* make copy */ |
---|
897 | luaK_reserveregs(fs, 1); |
---|
898 | } |
---|
899 | } |
---|
900 | |
---|
901 | |
---|
902 | static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) { |
---|
903 | expdesc e; |
---|
904 | check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED, |
---|
905 | "syntax error"); |
---|
906 | if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */ |
---|
907 | struct LHS_assign nv; |
---|
908 | nv.prev = lh; |
---|
909 | primaryexp(ls, &nv.v); |
---|
910 | if (nv.v.k == VLOCAL) |
---|
911 | check_conflict(ls, lh, &nv.v); |
---|
912 | assignment(ls, &nv, nvars+1); |
---|
913 | } |
---|
914 | else { /* assignment -> `=' explist1 */ |
---|
915 | int nexps; |
---|
916 | check(ls, '='); |
---|
917 | nexps = explist1(ls, &e); |
---|
918 | if (nexps != nvars) { |
---|
919 | adjust_assign(ls, nvars, nexps, &e); |
---|
920 | if (nexps > nvars) |
---|
921 | ls->fs->freereg -= nexps - nvars; /* remove extra values */ |
---|
922 | } |
---|
923 | else { |
---|
924 | luaK_setcallreturns(ls->fs, &e, 1); /* close last expression */ |
---|
925 | luaK_storevar(ls->fs, &lh->v, &e); |
---|
926 | return; /* avoid default */ |
---|
927 | } |
---|
928 | } |
---|
929 | init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */ |
---|
930 | luaK_storevar(ls->fs, &lh->v, &e); |
---|
931 | } |
---|
932 | |
---|
933 | |
---|
934 | static void cond (LexState *ls, expdesc *v) { |
---|
935 | /* cond -> exp */ |
---|
936 | expr(ls, v); /* read condition */ |
---|
937 | if (v->k == VNIL) v->k = VFALSE; /* `falses' are all equal here */ |
---|
938 | luaK_goiftrue(ls->fs, v); |
---|
939 | luaK_patchtohere(ls->fs, v->t); |
---|
940 | } |
---|
941 | |
---|
942 | |
---|
943 | /* |
---|
944 | ** The while statement optimizes its code by coding the condition |
---|
945 | ** after its body (and thus avoiding one jump in the loop). |
---|
946 | */ |
---|
947 | |
---|
948 | /* |
---|
949 | ** maximum size of expressions for optimizing `while' code |
---|
950 | */ |
---|
951 | #ifndef MAXEXPWHILE |
---|
952 | #define MAXEXPWHILE 100 |
---|
953 | #endif |
---|
954 | |
---|
955 | /* |
---|
956 | ** the call `luaK_goiffalse' may grow the size of an expression by |
---|
957 | ** at most this: |
---|
958 | */ |
---|
959 | #define EXTRAEXP 5 |
---|
960 | |
---|
961 | static void whilestat (LexState *ls, int line) { |
---|
962 | /* whilestat -> WHILE cond DO block END */ |
---|
963 | Instruction codeexp[MAXEXPWHILE + EXTRAEXP]; |
---|
964 | int lineexp; |
---|
965 | int i; |
---|
966 | int sizeexp; |
---|
967 | FuncState *fs = ls->fs; |
---|
968 | int whileinit, blockinit, expinit; |
---|
969 | expdesc v; |
---|
970 | BlockCnt bl; |
---|
971 | next(ls); /* skip WHILE */ |
---|
972 | whileinit = luaK_jump(fs); /* jump to condition (which will be moved) */ |
---|
973 | expinit = luaK_getlabel(fs); |
---|
974 | expr(ls, &v); /* parse condition */ |
---|
975 | if (v.k == VK) v.k = VTRUE; /* `trues' are all equal here */ |
---|
976 | lineexp = ls->linenumber; |
---|
977 | luaK_goiffalse(fs, &v); |
---|
978 | luaK_concat(fs, &v.f, fs->jpc); |
---|
979 | fs->jpc = NO_JUMP; |
---|
980 | sizeexp = fs->pc - expinit; /* size of expression code */ |
---|
981 | if (sizeexp > MAXEXPWHILE) |
---|
982 | luaX_syntaxerror(ls, "`while' condition too complex"); |
---|
983 | for (i = 0; i < sizeexp; i++) /* save `exp' code */ |
---|
984 | codeexp[i] = fs->f->code[expinit + i]; |
---|
985 | fs->pc = expinit; /* remove `exp' code */ |
---|
986 | enterblock(fs, &bl, 1); |
---|
987 | check(ls, TK_DO); |
---|
988 | blockinit = luaK_getlabel(fs); |
---|
989 | block(ls); |
---|
990 | luaK_patchtohere(fs, whileinit); /* initial jump jumps to here */ |
---|
991 | /* move `exp' back to code */ |
---|
992 | if (v.t != NO_JUMP) v.t += fs->pc - expinit; |
---|
993 | if (v.f != NO_JUMP) v.f += fs->pc - expinit; |
---|
994 | for (i=0; i<sizeexp; i++) |
---|
995 | luaK_code(fs, codeexp[i], lineexp); |
---|
996 | check_match(ls, TK_END, TK_WHILE, line); |
---|
997 | leaveblock(fs); |
---|
998 | luaK_patchlist(fs, v.t, blockinit); /* true conditions go back to loop */ |
---|
999 | luaK_patchtohere(fs, v.f); /* false conditions finish the loop */ |
---|
1000 | } |
---|
1001 | |
---|
1002 | |
---|
1003 | static void repeatstat (LexState *ls, int line) { |
---|
1004 | /* repeatstat -> REPEAT block UNTIL cond */ |
---|
1005 | FuncState *fs = ls->fs; |
---|
1006 | int repeat_init = luaK_getlabel(fs); |
---|
1007 | expdesc v; |
---|
1008 | BlockCnt bl; |
---|
1009 | enterblock(fs, &bl, 1); |
---|
1010 | next(ls); |
---|
1011 | block(ls); |
---|
1012 | check_match(ls, TK_UNTIL, TK_REPEAT, line); |
---|
1013 | cond(ls, &v); |
---|
1014 | luaK_patchlist(fs, v.f, repeat_init); |
---|
1015 | leaveblock(fs); |
---|
1016 | } |
---|
1017 | |
---|
1018 | |
---|
1019 | static int exp1 (LexState *ls) { |
---|
1020 | expdesc e; |
---|
1021 | int k; |
---|
1022 | expr(ls, &e); |
---|
1023 | k = e.k; |
---|
1024 | luaK_exp2nextreg(ls->fs, &e); |
---|
1025 | return k; |
---|
1026 | } |
---|
1027 | |
---|
1028 | |
---|
1029 | static void forbody (LexState *ls, int base, int line, int nvars, int isnum) { |
---|
1030 | BlockCnt bl; |
---|
1031 | FuncState *fs = ls->fs; |
---|
1032 | int prep, endfor; |
---|
1033 | adjustlocalvars(ls, nvars); /* scope for all variables */ |
---|
1034 | check(ls, TK_DO); |
---|
1035 | enterblock(fs, &bl, 1); /* loop block */ |
---|
1036 | prep = luaK_getlabel(fs); |
---|
1037 | block(ls); |
---|
1038 | luaK_patchtohere(fs, prep-1); |
---|
1039 | endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) : |
---|
1040 | luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars - 3); |
---|
1041 | luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */ |
---|
1042 | luaK_patchlist(fs, (isnum) ? endfor : luaK_jump(fs), prep); |
---|
1043 | leaveblock(fs); |
---|
1044 | } |
---|
1045 | |
---|
1046 | |
---|
1047 | static void fornum (LexState *ls, TString *varname, int line) { |
---|
1048 | /* fornum -> NAME = exp1,exp1[,exp1] DO body */ |
---|
1049 | FuncState *fs = ls->fs; |
---|
1050 | int base = fs->freereg; |
---|
1051 | new_localvar(ls, varname, 0); |
---|
1052 | new_localvarstr(ls, "(for limit)", 1); |
---|
1053 | new_localvarstr(ls, "(for step)", 2); |
---|
1054 | check(ls, '='); |
---|
1055 | exp1(ls); /* initial value */ |
---|
1056 | check(ls, ','); |
---|
1057 | exp1(ls); /* limit */ |
---|
1058 | if (testnext(ls, ',')) |
---|
1059 | exp1(ls); /* optional step */ |
---|
1060 | else { /* default step = 1 */ |
---|
1061 | luaK_codeABx(fs, OP_LOADK, fs->freereg, luaK_numberK(fs, 1)); |
---|
1062 | luaK_reserveregs(fs, 1); |
---|
1063 | } |
---|
1064 | luaK_codeABC(fs, OP_SUB, fs->freereg - 3, fs->freereg - 3, fs->freereg - 1); |
---|
1065 | luaK_jump(fs); |
---|
1066 | forbody(ls, base, line, 3, 1); |
---|
1067 | } |
---|
1068 | |
---|
1069 | |
---|
1070 | static void forlist (LexState *ls, TString *indexname) { |
---|
1071 | /* forlist -> NAME {,NAME} IN explist1 DO body */ |
---|
1072 | FuncState *fs = ls->fs; |
---|
1073 | expdesc e; |
---|
1074 | int nvars = 0; |
---|
1075 | int line; |
---|
1076 | int base = fs->freereg; |
---|
1077 | new_localvarstr(ls, "(for generator)", nvars++); |
---|
1078 | new_localvarstr(ls, "(for state)", nvars++); |
---|
1079 | new_localvar(ls, indexname, nvars++); |
---|
1080 | while (testnext(ls, ',')) |
---|
1081 | new_localvar(ls, str_checkname(ls), nvars++); |
---|
1082 | check(ls, TK_IN); |
---|
1083 | line = ls->linenumber; |
---|
1084 | adjust_assign(ls, nvars, explist1(ls, &e), &e); |
---|
1085 | luaK_checkstack(fs, 3); /* extra space to call generator */ |
---|
1086 | luaK_codeAsBx(fs, OP_TFORPREP, base, NO_JUMP); |
---|
1087 | forbody(ls, base, line, nvars, 0); |
---|
1088 | } |
---|
1089 | |
---|
1090 | |
---|
1091 | static void forstat (LexState *ls, int line) { |
---|
1092 | /* forstat -> fornum | forlist */ |
---|
1093 | FuncState *fs = ls->fs; |
---|
1094 | TString *varname; |
---|
1095 | BlockCnt bl; |
---|
1096 | enterblock(fs, &bl, 0); /* block to control variable scope */ |
---|
1097 | next(ls); /* skip `for' */ |
---|
1098 | varname = str_checkname(ls); /* first variable name */ |
---|
1099 | switch (ls->t.token) { |
---|
1100 | case '=': fornum(ls, varname, line); break; |
---|
1101 | case ',': case TK_IN: forlist(ls, varname); break; |
---|
1102 | default: luaX_syntaxerror(ls, "`=' or `in' expected"); |
---|
1103 | } |
---|
1104 | check_match(ls, TK_END, TK_FOR, line); |
---|
1105 | leaveblock(fs); |
---|
1106 | } |
---|
1107 | |
---|
1108 | |
---|
1109 | static void test_then_block (LexState *ls, expdesc *v) { |
---|
1110 | /* test_then_block -> [IF | ELSEIF] cond THEN block */ |
---|
1111 | next(ls); /* skip IF or ELSEIF */ |
---|
1112 | cond(ls, v); |
---|
1113 | check(ls, TK_THEN); |
---|
1114 | block(ls); /* `then' part */ |
---|
1115 | } |
---|
1116 | |
---|
1117 | |
---|
1118 | static void ifstat (LexState *ls, int line) { |
---|
1119 | /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */ |
---|
1120 | FuncState *fs = ls->fs; |
---|
1121 | expdesc v; |
---|
1122 | int escapelist = NO_JUMP; |
---|
1123 | test_then_block(ls, &v); /* IF cond THEN block */ |
---|
1124 | while (ls->t.token == TK_ELSEIF) { |
---|
1125 | luaK_concat(fs, &escapelist, luaK_jump(fs)); |
---|
1126 | luaK_patchtohere(fs, v.f); |
---|
1127 | test_then_block(ls, &v); /* ELSEIF cond THEN block */ |
---|
1128 | } |
---|
1129 | if (ls->t.token == TK_ELSE) { |
---|
1130 | luaK_concat(fs, &escapelist, luaK_jump(fs)); |
---|
1131 | luaK_patchtohere(fs, v.f); |
---|
1132 | next(ls); /* skip ELSE (after patch, for correct line info) */ |
---|
1133 | block(ls); /* `else' part */ |
---|
1134 | } |
---|
1135 | else |
---|
1136 | luaK_concat(fs, &escapelist, v.f); |
---|
1137 | luaK_patchtohere(fs, escapelist); |
---|
1138 | check_match(ls, TK_END, TK_IF, line); |
---|
1139 | } |
---|
1140 | |
---|
1141 | |
---|
1142 | static void localfunc (LexState *ls) { |
---|
1143 | expdesc v, b; |
---|
1144 | FuncState *fs = ls->fs; |
---|
1145 | new_localvar(ls, str_checkname(ls), 0); |
---|
1146 | init_exp(&v, VLOCAL, fs->freereg); |
---|
1147 | luaK_reserveregs(fs, 1); |
---|
1148 | adjustlocalvars(ls, 1); |
---|
1149 | body(ls, &b, 0, ls->linenumber); |
---|
1150 | luaK_storevar(fs, &v, &b); |
---|
1151 | /* debug information will only see the variable after this point! */ |
---|
1152 | getlocvar(fs, fs->nactvar - 1).startpc = fs->pc; |
---|
1153 | } |
---|
1154 | |
---|
1155 | |
---|
1156 | static void localstat (LexState *ls) { |
---|
1157 | /* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */ |
---|
1158 | int nvars = 0; |
---|
1159 | int nexps; |
---|
1160 | expdesc e; |
---|
1161 | do { |
---|
1162 | new_localvar(ls, str_checkname(ls), nvars++); |
---|
1163 | } while (testnext(ls, ',')); |
---|
1164 | if (testnext(ls, '=')) |
---|
1165 | nexps = explist1(ls, &e); |
---|
1166 | else { |
---|
1167 | e.k = VVOID; |
---|
1168 | nexps = 0; |
---|
1169 | } |
---|
1170 | adjust_assign(ls, nvars, nexps, &e); |
---|
1171 | adjustlocalvars(ls, nvars); |
---|
1172 | } |
---|
1173 | |
---|
1174 | |
---|
1175 | static int funcname (LexState *ls, expdesc *v) { |
---|
1176 | /* funcname -> NAME {field} [`:' NAME] */ |
---|
1177 | int needself = 0; |
---|
1178 | singlevar(ls, v, 1); |
---|
1179 | while (ls->t.token == '.') |
---|
1180 | luaY_field(ls, v); |
---|
1181 | if (ls->t.token == ':') { |
---|
1182 | needself = 1; |
---|
1183 | luaY_field(ls, v); |
---|
1184 | } |
---|
1185 | return needself; |
---|
1186 | } |
---|
1187 | |
---|
1188 | |
---|
1189 | static void funcstat (LexState *ls, int line) { |
---|
1190 | /* funcstat -> FUNCTION funcname body */ |
---|
1191 | int needself; |
---|
1192 | expdesc v, b; |
---|
1193 | next(ls); /* skip FUNCTION */ |
---|
1194 | needself = funcname(ls, &v); |
---|
1195 | body(ls, &b, needself, line); |
---|
1196 | luaK_storevar(ls->fs, &v, &b); |
---|
1197 | luaK_fixline(ls->fs, line); /* definition `happens' in the first line */ |
---|
1198 | } |
---|
1199 | |
---|
1200 | |
---|
1201 | static void exprstat (LexState *ls) { |
---|
1202 | /* stat -> func | assignment */ |
---|
1203 | FuncState *fs = ls->fs; |
---|
1204 | struct LHS_assign v; |
---|
1205 | primaryexp(ls, &v.v); |
---|
1206 | if (v.v.k == VCALL) { /* stat -> func */ |
---|
1207 | luaK_setcallreturns(fs, &v.v, 0); /* call statement uses no results */ |
---|
1208 | } |
---|
1209 | else { /* stat -> assignment */ |
---|
1210 | v.prev = NULL; |
---|
1211 | assignment(ls, &v, 1); |
---|
1212 | } |
---|
1213 | } |
---|
1214 | |
---|
1215 | |
---|
1216 | static void retstat (LexState *ls) { |
---|
1217 | /* stat -> RETURN explist */ |
---|
1218 | FuncState *fs = ls->fs; |
---|
1219 | expdesc e; |
---|
1220 | int first, nret; /* registers with returned values */ |
---|
1221 | next(ls); /* skip RETURN */ |
---|
1222 | if (block_follow(ls->t.token) || ls->t.token == ';') |
---|
1223 | first = nret = 0; /* return no values */ |
---|
1224 | else { |
---|
1225 | nret = explist1(ls, &e); /* optional return values */ |
---|
1226 | if (e.k == VCALL) { |
---|
1227 | luaK_setcallreturns(fs, &e, LUA_MULTRET); |
---|
1228 | if (nret == 1) { /* tail call? */ |
---|
1229 | SET_OPCODE(getcode(fs,&e), OP_TAILCALL); |
---|
1230 | lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar); |
---|
1231 | } |
---|
1232 | first = fs->nactvar; |
---|
1233 | nret = LUA_MULTRET; /* return all values */ |
---|
1234 | } |
---|
1235 | else { |
---|
1236 | if (nret == 1) /* only one single value? */ |
---|
1237 | first = luaK_exp2anyreg(fs, &e); |
---|
1238 | else { |
---|
1239 | luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */ |
---|
1240 | first = fs->nactvar; /* return all `active' values */ |
---|
1241 | lua_assert(nret == fs->freereg - first); |
---|
1242 | } |
---|
1243 | } |
---|
1244 | } |
---|
1245 | luaK_codeABC(fs, OP_RETURN, first, nret+1, 0); |
---|
1246 | } |
---|
1247 | |
---|
1248 | |
---|
1249 | static void breakstat (LexState *ls) { |
---|
1250 | /* stat -> BREAK [NAME] */ |
---|
1251 | FuncState *fs = ls->fs; |
---|
1252 | BlockCnt *bl = fs->bl; |
---|
1253 | int upval = 0; |
---|
1254 | next(ls); /* skip BREAK */ |
---|
1255 | while (bl && !bl->isbreakable) { |
---|
1256 | upval |= bl->upval; |
---|
1257 | bl = bl->previous; |
---|
1258 | } |
---|
1259 | if (!bl) |
---|
1260 | luaX_syntaxerror(ls, "no loop to break"); |
---|
1261 | if (upval) |
---|
1262 | luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0); |
---|
1263 | luaK_concat(fs, &bl->breaklist, luaK_jump(fs)); |
---|
1264 | } |
---|
1265 | |
---|
1266 | |
---|
1267 | static int statement (LexState *ls) { |
---|
1268 | int line = ls->linenumber; /* may be needed for error messages */ |
---|
1269 | switch (ls->t.token) { |
---|
1270 | case TK_IF: { /* stat -> ifstat */ |
---|
1271 | ifstat(ls, line); |
---|
1272 | return 0; |
---|
1273 | } |
---|
1274 | case TK_WHILE: { /* stat -> whilestat */ |
---|
1275 | whilestat(ls, line); |
---|
1276 | return 0; |
---|
1277 | } |
---|
1278 | case TK_DO: { /* stat -> DO block END */ |
---|
1279 | next(ls); /* skip DO */ |
---|
1280 | block(ls); |
---|
1281 | check_match(ls, TK_END, TK_DO, line); |
---|
1282 | return 0; |
---|
1283 | } |
---|
1284 | case TK_FOR: { /* stat -> forstat */ |
---|
1285 | forstat(ls, line); |
---|
1286 | return 0; |
---|
1287 | } |
---|
1288 | case TK_REPEAT: { /* stat -> repeatstat */ |
---|
1289 | repeatstat(ls, line); |
---|
1290 | return 0; |
---|
1291 | } |
---|
1292 | case TK_FUNCTION: { |
---|
1293 | funcstat(ls, line); /* stat -> funcstat */ |
---|
1294 | return 0; |
---|
1295 | } |
---|
1296 | case TK_LOCAL: { /* stat -> localstat */ |
---|
1297 | next(ls); /* skip LOCAL */ |
---|
1298 | if (testnext(ls, TK_FUNCTION)) /* local function? */ |
---|
1299 | localfunc(ls); |
---|
1300 | else |
---|
1301 | localstat(ls); |
---|
1302 | return 0; |
---|
1303 | } |
---|
1304 | case TK_RETURN: { /* stat -> retstat */ |
---|
1305 | retstat(ls); |
---|
1306 | return 1; /* must be last statement */ |
---|
1307 | } |
---|
1308 | case TK_BREAK: { /* stat -> breakstat */ |
---|
1309 | breakstat(ls); |
---|
1310 | return 1; /* must be last statement */ |
---|
1311 | } |
---|
1312 | default: { |
---|
1313 | exprstat(ls); |
---|
1314 | return 0; /* to avoid warnings */ |
---|
1315 | } |
---|
1316 | } |
---|
1317 | } |
---|
1318 | |
---|
1319 | |
---|
1320 | static void chunk (LexState *ls) { |
---|
1321 | /* chunk -> { stat [`;'] } */ |
---|
1322 | int islast = 0; |
---|
1323 | enterlevel(ls); |
---|
1324 | while (!islast && !block_follow(ls->t.token)) { |
---|
1325 | islast = statement(ls); |
---|
1326 | testnext(ls, ';'); |
---|
1327 | lua_assert(ls->fs->freereg >= ls->fs->nactvar); |
---|
1328 | ls->fs->freereg = ls->fs->nactvar; /* free registers */ |
---|
1329 | } |
---|
1330 | leavelevel(ls); |
---|
1331 | } |
---|
1332 | |
---|
1333 | /* }====================================================================== */ |
---|