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hexadecimal escape sequences in strings + better error messages for

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bad decimal escape sequences
This commit is contained in:
Roberto Ierusalimschy 2009-05-18 14:28:04 -03:00
parent 6956331093
commit 889284ebd0
1 changed files with 55 additions and 22 deletions
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77
llex.c
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@ -1,5 +1,5 @@
/*
** $Id: llex.c,v 2.31 2009/02/19 17:18:25 roberto Exp roberto $
** $Id: llex.c,v 2.32 2009/03/11 13:27:32 roberto Exp roberto $
** Lexical Analyzer
** See Copyright Notice in lua.h
*/
@ -29,7 +29,6 @@
#define currIsNewline(ls) (ls->current == '\n' || ls->current == '\r')
@ -52,14 +51,14 @@ static void lexerror (LexState *ls, const char *msg, int token);
static void save (LexState *ls, int c) {
Mbuffer *b = ls->buff;
if (b->n + 1 > b->buffsize) {
if (luaZ_bufflen(b) + 1 > luaZ_sizebuffer(b)) {
size_t newsize;
if (b->buffsize >= MAX_SIZET/2)
if (luaZ_sizebuffer(b) >= MAX_SIZET/2)
lexerror(ls, "lexical element too long", 0);
newsize = b->buffsize * 2;
newsize = luaZ_sizebuffer(b) * 2;
luaZ_resizebuffer(ls->L, b, newsize);
}
b->buffer[b->n++] = cast(char, c);
b->buffer[luaZ_bufflen(b)++] = cast(char, c);
}
@ -264,6 +263,48 @@ static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) {
}
static int hexavalue (int c) {
if (lisdigit(c)) return c - '0';
else if (lisupper(c)) return c - 'A' + 10;
else return c - 'a' + 10;
}
static int readhexaesc (LexState *ls) {
int c1, c2 = EOZ;
if (!lisxdigit(c1 = next(ls)) || !lisxdigit(c2 = next(ls))) {
luaZ_resetbuffer(ls->buff); /* prepare error message */
save(ls, '\\'); save(ls, 'x');
if (c1 != EOZ) save(ls, c1);
if (c2 != EOZ) save(ls, c2);
lexerror(ls, "hexadecimal digit expected", TK_STRING);
}
return (hexavalue(c1) << 4) + hexavalue(c2);
}
static int readdecesc (LexState *ls) {
int c1 = ls->current, c2, c3;
int c = c1 - '0';
if (lisdigit(c2 = next(ls))) {
c = 10*c + c2 - '0';
if (lisdigit(c3 = next(ls))) {
c = 10*c + c3 - '0';
if (c > UCHAR_MAX) {
luaZ_resetbuffer(ls->buff); /* prepare error message */
save(ls, '\\');
save(ls, c1); save(ls, c2); save(ls, c3);
lexerror(ls, "decimal escape too large", TK_STRING);
}
return c;
}
}
/* else, has read one character that was not a digit */
zungetc(ls->z); /* return it to input stream */
return c;
}
static void read_string (LexState *ls, int del, SemInfo *seminfo) {
save_and_next(ls);
while (ls->current != del) {
@ -275,8 +316,8 @@ static void read_string (LexState *ls, int del, SemInfo *seminfo) {
case '\r':
lexerror(ls, "unfinished string", TK_STRING);
continue; /* to avoid warnings */
case '\\': {
int c;
case '\\': { /* escape sequences */
int c; /* final character to be saved */
next(ls); /* do not save the `\' */
switch (ls->current) {
case 'a': c = '\a'; break;
@ -286,28 +327,20 @@ static void read_string (LexState *ls, int del, SemInfo *seminfo) {
case 'r': c = '\r'; break;
case 't': c = '\t'; break;
case 'v': c = '\v'; break;
case 'x': c = readhexaesc(ls); break;
case '\n':
case '\r': save(ls, '\n'); inclinenumber(ls); continue;
case EOZ: continue; /* will raise an error next loop */
default: {
if (!lisdigit(ls->current))
save_and_next(ls); /* handles \\, \", \', and \? */
else { /* \xxx */
int i = 0;
c = 0;
do {
c = 10*c + (ls->current-'0');
next(ls);
} while (++i<3 && lisdigit(ls->current));
if (c > UCHAR_MAX)
lexerror(ls, "escape sequence too large", TK_STRING);
save(ls, c);
}
continue;
c = ls->current; /* handles \\, \", \', and \? */
else /* digital escape \ddd */
c = readdecesc(ls);
break;
}
}
save(ls, c);
next(ls);
save(ls, c);
continue;
}
default: