0,0 → 1,516 |
/* |
** $Id: llex.c,v 2.59 2011/11/30 12:43:51 roberto Exp $ |
** Lexical Analyzer |
** See Copyright Notice in lua.h |
*/ |
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#include <locale.h> |
#include <string.h> |
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#define llex_c |
#define LUA_CORE |
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#include "lua.h" |
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#include "lctype.h" |
#include "ldo.h" |
#include "llex.h" |
#include "lobject.h" |
#include "lparser.h" |
#include "lstate.h" |
#include "lstring.h" |
#include "ltable.h" |
#include "lzio.h" |
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#define next(ls) (ls->current = zgetc(ls->z)) |
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#define currIsNewline(ls) (ls->current == '\n' || ls->current == '\r') |
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/* ORDER RESERVED */ |
static const char *const luaX_tokens [] = { |
"and", "break", "do", "else", "elseif", |
"end", "false", "for", "function", "goto", "if", |
"in", "local", "nil", "not", "or", "repeat", |
"return", "then", "true", "until", "while", |
"..", "...", "==", ">=", "<=", "~=", "::", "<eof>", |
"<number>", "<name>", "<string>" |
}; |
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#define save_and_next(ls) (save(ls, ls->current), next(ls)) |
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static l_noret lexerror (LexState *ls, const char *msg, int token); |
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static void save (LexState *ls, int c) { |
Mbuffer *b = ls->buff; |
if (luaZ_bufflen(b) + 1 > luaZ_sizebuffer(b)) { |
size_t newsize; |
if (luaZ_sizebuffer(b) >= MAX_SIZET/2) |
lexerror(ls, "lexical element too long", 0); |
newsize = luaZ_sizebuffer(b) * 2; |
luaZ_resizebuffer(ls->L, b, newsize); |
} |
b->buffer[luaZ_bufflen(b)++] = cast(char, c); |
} |
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void luaX_init (lua_State *L) { |
int i; |
for (i=0; i<NUM_RESERVED; i++) { |
TString *ts = luaS_new(L, luaX_tokens[i]); |
luaS_fix(ts); /* reserved words are never collected */ |
ts->tsv.reserved = cast_byte(i+1); /* reserved word */ |
} |
} |
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const char *luaX_token2str (LexState *ls, int token) { |
if (token < FIRST_RESERVED) { |
lua_assert(token == cast(unsigned char, token)); |
return (lisprint(token)) ? luaO_pushfstring(ls->L, LUA_QL("%c"), token) : |
luaO_pushfstring(ls->L, "char(%d)", token); |
} |
else { |
const char *s = luaX_tokens[token - FIRST_RESERVED]; |
if (token < TK_EOS) |
return luaO_pushfstring(ls->L, LUA_QS, s); |
else |
return s; |
} |
} |
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static const char *txtToken (LexState *ls, int token) { |
switch (token) { |
case TK_NAME: |
case TK_STRING: |
case TK_NUMBER: |
save(ls, '\0'); |
return luaO_pushfstring(ls->L, LUA_QS, luaZ_buffer(ls->buff)); |
default: |
return luaX_token2str(ls, token); |
} |
} |
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static l_noret lexerror (LexState *ls, const char *msg, int token) { |
char buff[LUA_IDSIZE]; |
luaO_chunkid(buff, getstr(ls->source), LUA_IDSIZE); |
msg = luaO_pushfstring(ls->L, "%s:%d: %s", buff, ls->linenumber, msg); |
if (token) |
luaO_pushfstring(ls->L, "%s near %s", msg, txtToken(ls, token)); |
luaD_throw(ls->L, LUA_ERRSYNTAX); |
} |
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l_noret luaX_syntaxerror (LexState *ls, const char *msg) { |
lexerror(ls, msg, ls->t.token); |
} |
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/* |
** creates a new string and anchors it in function's table so that |
** it will not be collected until the end of the function's compilation |
** (by that time it should be anchored in function's prototype) |
*/ |
TString *luaX_newstring (LexState *ls, const char *str, size_t l) { |
lua_State *L = ls->L; |
TValue *o; /* entry for `str' */ |
TString *ts = luaS_newlstr(L, str, l); /* create new string */ |
setsvalue2s(L, L->top++, ts); /* temporarily anchor it in stack */ |
o = luaH_set(L, ls->fs->h, L->top - 1); |
if (ttisnil(o)) { /* not in use yet? (see 'addK') */ |
/* boolean value does not need GC barrier; |
table has no metatable, so it does not need to invalidate cache */ |
setbvalue(o, 1); /* t[string] = true */ |
luaC_checkGC(L); |
} |
L->top--; /* remove string from stack */ |
return ts; |
} |
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/* |
** increment line number and skips newline sequence (any of |
** \n, \r, \n\r, or \r\n) |
*/ |
static void inclinenumber (LexState *ls) { |
int old = ls->current; |
lua_assert(currIsNewline(ls)); |
next(ls); /* skip `\n' or `\r' */ |
if (currIsNewline(ls) && ls->current != old) |
next(ls); /* skip `\n\r' or `\r\n' */ |
if (++ls->linenumber >= MAX_INT) |
luaX_syntaxerror(ls, "chunk has too many lines"); |
} |
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void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source, |
int firstchar) { |
ls->decpoint = '.'; |
ls->L = L; |
ls->current = firstchar; |
ls->lookahead.token = TK_EOS; /* no look-ahead token */ |
ls->z = z; |
ls->fs = NULL; |
ls->linenumber = 1; |
ls->lastline = 1; |
ls->source = source; |
ls->envn = luaS_new(L, LUA_ENV); /* create env name */ |
luaS_fix(ls->envn); /* never collect this name */ |
luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER); /* initialize buffer */ |
} |
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/* |
** ======================================================= |
** LEXICAL ANALYZER |
** ======================================================= |
*/ |
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static int check_next (LexState *ls, const char *set) { |
if (ls->current == '\0' || !strchr(set, ls->current)) |
return 0; |
save_and_next(ls); |
return 1; |
} |
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/* |
** change all characters 'from' in buffer to 'to' |
*/ |
static void buffreplace (LexState *ls, char from, char to) { |
size_t n = luaZ_bufflen(ls->buff); |
char *p = luaZ_buffer(ls->buff); |
while (n--) |
if (p[n] == from) p[n] = to; |
} |
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#if !defined(getlocaledecpoint) |
#define getlocaledecpoint() (localeconv()->decimal_point[0]) |
#endif |
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#define buff2d(b,e) luaO_str2d(luaZ_buffer(b), luaZ_bufflen(b) - 1, e) |
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/* |
** in case of format error, try to change decimal point separator to |
** the one defined in the current locale and check again |
*/ |
static void trydecpoint (LexState *ls, SemInfo *seminfo) { |
char old = ls->decpoint; |
ls->decpoint = getlocaledecpoint(); |
buffreplace(ls, old, ls->decpoint); /* try new decimal separator */ |
if (!buff2d(ls->buff, &seminfo->r)) { |
/* format error with correct decimal point: no more options */ |
buffreplace(ls, ls->decpoint, '.'); /* undo change (for error message) */ |
lexerror(ls, "malformed number", TK_NUMBER); |
} |
} |
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/* LUA_NUMBER */ |
static void read_numeral (LexState *ls, SemInfo *seminfo) { |
lua_assert(lisdigit(ls->current)); |
do { |
save_and_next(ls); |
if (check_next(ls, "EePp")) /* exponent part? */ |
check_next(ls, "+-"); /* optional exponent sign */ |
} while (lislalnum(ls->current) || ls->current == '.'); |
save(ls, '\0'); |
buffreplace(ls, '.', ls->decpoint); /* follow locale for decimal point */ |
if (!buff2d(ls->buff, &seminfo->r)) /* format error? */ |
trydecpoint(ls, seminfo); /* try to update decimal point separator */ |
} |
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/* |
** skip a sequence '[=*[' or ']=*]' and return its number of '='s or |
** -1 if sequence is malformed |
*/ |
static int skip_sep (LexState *ls) { |
int count = 0; |
int s = ls->current; |
lua_assert(s == '[' || s == ']'); |
save_and_next(ls); |
while (ls->current == '=') { |
save_and_next(ls); |
count++; |
} |
return (ls->current == s) ? count : (-count) - 1; |
} |
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static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) { |
save_and_next(ls); /* skip 2nd `[' */ |
if (currIsNewline(ls)) /* string starts with a newline? */ |
inclinenumber(ls); /* skip it */ |
for (;;) { |
switch (ls->current) { |
case EOZ: |
lexerror(ls, (seminfo) ? "unfinished long string" : |
"unfinished long comment", TK_EOS); |
break; /* to avoid warnings */ |
case ']': { |
if (skip_sep(ls) == sep) { |
save_and_next(ls); /* skip 2nd `]' */ |
goto endloop; |
} |
break; |
} |
case '\n': case '\r': { |
save(ls, '\n'); |
inclinenumber(ls); |
if (!seminfo) luaZ_resetbuffer(ls->buff); /* avoid wasting space */ |
break; |
} |
default: { |
if (seminfo) save_and_next(ls); |
else next(ls); |
} |
} |
} endloop: |
if (seminfo) |
seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + (2 + sep), |
luaZ_bufflen(ls->buff) - 2*(2 + sep)); |
} |
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static void escerror (LexState *ls, int *c, int n, const char *msg) { |
int i; |
luaZ_resetbuffer(ls->buff); /* prepare error message */ |
save(ls, '\\'); |
for (i = 0; i < n && c[i] != EOZ; i++) |
save(ls, c[i]); |
lexerror(ls, msg, TK_STRING); |
} |
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static int readhexaesc (LexState *ls) { |
int c[3], i; /* keep input for error message */ |
int r = 0; /* result accumulator */ |
c[0] = 'x'; /* for error message */ |
for (i = 1; i < 3; i++) { /* read two hexa digits */ |
c[i] = next(ls); |
if (!lisxdigit(c[i])) |
escerror(ls, c, i + 1, "hexadecimal digit expected"); |
r = (r << 4) + luaO_hexavalue(c[i]); |
} |
return r; |
} |
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static int readdecesc (LexState *ls) { |
int c[3], i; |
int r = 0; /* result accumulator */ |
for (i = 0; i < 3 && lisdigit(ls->current); i++) { /* read up to 3 digits */ |
c[i] = ls->current; |
r = 10*r + c[i] - '0'; |
next(ls); |
} |
if (r > UCHAR_MAX) |
escerror(ls, c, i, "decimal escape too large"); |
return r; |
} |
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static void read_string (LexState *ls, int del, SemInfo *seminfo) { |
save_and_next(ls); /* keep delimiter (for error messages) */ |
while (ls->current != del) { |
switch (ls->current) { |
case EOZ: |
lexerror(ls, "unfinished string", TK_EOS); |
break; /* to avoid warnings */ |
case '\n': |
case '\r': |
lexerror(ls, "unfinished string", TK_STRING); |
break; /* to avoid warnings */ |
case '\\': { /* escape sequences */ |
int c; /* final character to be saved */ |
next(ls); /* do not save the `\' */ |
switch (ls->current) { |
case 'a': c = '\a'; goto read_save; |
case 'b': c = '\b'; goto read_save; |
case 'f': c = '\f'; goto read_save; |
case 'n': c = '\n'; goto read_save; |
case 'r': c = '\r'; goto read_save; |
case 't': c = '\t'; goto read_save; |
case 'v': c = '\v'; goto read_save; |
case 'x': c = readhexaesc(ls); goto read_save; |
case '\n': case '\r': |
inclinenumber(ls); c = '\n'; goto only_save; |
case '\\': case '\"': case '\'': |
c = ls->current; goto read_save; |
case EOZ: goto no_save; /* will raise an error next loop */ |
case 'z': { /* zap following span of spaces */ |
next(ls); /* skip the 'z' */ |
while (lisspace(ls->current)) { |
if (currIsNewline(ls)) inclinenumber(ls); |
else next(ls); |
} |
goto no_save; |
} |
default: { |
if (!lisdigit(ls->current)) |
escerror(ls, &ls->current, 1, "invalid escape sequence"); |
/* digital escape \ddd */ |
c = readdecesc(ls); |
goto only_save; |
} |
} |
read_save: next(ls); /* read next character */ |
only_save: save(ls, c); /* save 'c' */ |
no_save: break; |
} |
default: |
save_and_next(ls); |
} |
} |
save_and_next(ls); /* skip delimiter */ |
seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + 1, |
luaZ_bufflen(ls->buff) - 2); |
} |
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static int llex (LexState *ls, SemInfo *seminfo) { |
luaZ_resetbuffer(ls->buff); |
for (;;) { |
switch (ls->current) { |
case '\n': case '\r': { /* line breaks */ |
inclinenumber(ls); |
break; |
} |
case ' ': case '\f': case '\t': case '\v': { /* spaces */ |
next(ls); |
break; |
} |
case '-': { /* '-' or '--' (comment) */ |
next(ls); |
if (ls->current != '-') return '-'; |
/* else is a comment */ |
next(ls); |
if (ls->current == '[') { /* long comment? */ |
int sep = skip_sep(ls); |
luaZ_resetbuffer(ls->buff); /* `skip_sep' may dirty the buffer */ |
if (sep >= 0) { |
read_long_string(ls, NULL, sep); /* skip long comment */ |
luaZ_resetbuffer(ls->buff); /* previous call may dirty the buff. */ |
break; |
} |
} |
/* else short comment */ |
while (!currIsNewline(ls) && ls->current != EOZ) |
next(ls); /* skip until end of line (or end of file) */ |
break; |
} |
case '[': { /* long string or simply '[' */ |
int sep = skip_sep(ls); |
if (sep >= 0) { |
read_long_string(ls, seminfo, sep); |
return TK_STRING; |
} |
else if (sep == -1) return '['; |
else lexerror(ls, "invalid long string delimiter", TK_STRING); |
} |
case '=': { |
next(ls); |
if (ls->current != '=') return '='; |
else { next(ls); return TK_EQ; } |
} |
case '<': { |
next(ls); |
if (ls->current != '=') return '<'; |
else { next(ls); return TK_LE; } |
} |
case '>': { |
next(ls); |
if (ls->current != '=') return '>'; |
else { next(ls); return TK_GE; } |
} |
case '~': { |
next(ls); |
if (ls->current != '=') return '~'; |
else { next(ls); return TK_NE; } |
} |
case ':': { |
next(ls); |
if (ls->current != ':') return ':'; |
else { next(ls); return TK_DBCOLON; } |
} |
case '"': case '\'': { /* short literal strings */ |
read_string(ls, ls->current, seminfo); |
return TK_STRING; |
} |
case '.': { /* '.', '..', '...', or number */ |
save_and_next(ls); |
if (check_next(ls, ".")) { |
if (check_next(ls, ".")) |
return TK_DOTS; /* '...' */ |
else return TK_CONCAT; /* '..' */ |
} |
else if (!lisdigit(ls->current)) return '.'; |
/* else go through */ |
} |
case '0': case '1': case '2': case '3': case '4': |
case '5': case '6': case '7': case '8': case '9': { |
read_numeral(ls, seminfo); |
return TK_NUMBER; |
} |
case EOZ: { |
return TK_EOS; |
} |
default: { |
if (lislalpha(ls->current)) { /* identifier or reserved word? */ |
TString *ts; |
do { |
save_and_next(ls); |
} while (lislalnum(ls->current)); |
ts = luaX_newstring(ls, luaZ_buffer(ls->buff), |
luaZ_bufflen(ls->buff)); |
seminfo->ts = ts; |
if (ts->tsv.reserved > 0) /* reserved word? */ |
return ts->tsv.reserved - 1 + FIRST_RESERVED; |
else { |
return TK_NAME; |
} |
} |
else { /* single-char tokens (+ - / ...) */ |
int c = ls->current; |
next(ls); |
return c; |
} |
} |
} |
} |
} |
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void luaX_next (LexState *ls) { |
ls->lastline = ls->linenumber; |
if (ls->lookahead.token != TK_EOS) { /* is there a look-ahead token? */ |
ls->t = ls->lookahead; /* use this one */ |
ls->lookahead.token = TK_EOS; /* and discharge it */ |
} |
else |
ls->t.token = llex(ls, &ls->t.seminfo); /* read next token */ |
} |
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int luaX_lookahead (LexState *ls) { |
lua_assert(ls->lookahead.token == TK_EOS); |
ls->lookahead.token = llex(ls, &ls->lookahead.seminfo); |
return ls->lookahead.token; |
} |
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