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 /* * proxy.c * lexer proxy for Lua parser -- implements __FILE__ and __LINE__ * Luiz Henrique de Figueiredo * This code is hereby placed in the public domain. * Add <<#include "proxy.c">> just before the definition of luaX_next in llex.c */ #include <string.h> static int nexttoken(LexState *ls, SemInfo *seminfo) { int t=llex(ls,seminfo); if (t==TK_NAME) { if (strcmp(getstr(seminfo->ts),"__FILE__")==0) { t=TK_STRING; seminfo->ts = ls->source; } else if (strcmp(getstr(seminfo->ts),"__LINE__")==0) { t=TK_NUMBER; seminfo->r = ls->linenumber; } } return t; } #define llex nexttoken 

An equivalent pure Lua code could be:

 function __FILE__() return debug.getinfo(2,'S').source end function __LINE__() return debug.getinfo(2, 'l').currentline end