scummvm/engines/grim/lua/llex.cpp
Paweł Kołodziejski 690f9d2a5c GRIM,LUA: Janitorial
2022-01-06 18:26:30 +01:00

447 lines
10 KiB
C++

/*
** Lexical Analizer
** See Copyright Notice in lua.h
*/
#define FORBIDDEN_SYMBOL_EXCEPTION_setjmp
#define FORBIDDEN_SYMBOL_EXCEPTION_longjmp
#include "common/util.h"
#include "engines/grim/lua/lauxlib.h"
#include "engines/grim/lua/llex.h"
#include "engines/grim/lua/lmem.h"
#include "engines/grim/lua/lobject.h"
#include "engines/grim/lua/lparser.h"
#include "engines/grim/lua/lstate.h"
#include "engines/grim/lua/lstring.h"
#include "engines/grim/lua/lstx.h"
#include "engines/grim/lua/luadebug.h"
#include "engines/grim/lua/lzio.h"
namespace Grim {
int32 lua_debug = 0;
#define next(LS) (LS->current = zgetc(LS->lex_z))
static struct {
const char *name;
int token;
} reserved [] = {
{"and", AND}, {"do", DO}, {"else", ELSE}, {"elseif", ELSEIF},
{"end", END}, {"function", FUNCTION}, {"if", IF}, {"local", LOCAL},
{"nil", NIL}, {"not", NOT}, {"or", OR}, {"repeat", REPEAT},
{"return", RETURN}, {"then", THEN}, {"until", UNTIL}, {"while", WHILE}
};
void luaX_init() {
uint32 i;
for (i = 0; i < (sizeof(reserved) / sizeof(reserved[0])); i++) {
TaggedString *ts = luaS_new(reserved[i].name);
ts->head.marked = reserved[i].token; /* reserved word (always > 255) */
}
}
static void firstline(LexState *LS) {
int32 c = zgetc(LS->lex_z);
if (c == '#') {
LS->linenumber++;
while ((c = zgetc(LS->lex_z)) != '\n' && c != EOZ) ; // skip first line
}
zungetc(LS->lex_z);
}
void luaX_setinput(ZIO *z) {
LexState *LS = lua_state->lexstate;
LS->current = '\n';
LS->linelasttoken = 0;
LS->linenumber = 0;
LS->iflevel = 0;
LS->ifstate[0].skip = 0;
LS->ifstate[0].elsepart = 1; // to avoid a free $else
LS->lex_z = z;
firstline(LS);
luaL_resetbuffer();
}
/*
** =======================================================
** PRAGMAS
** =======================================================
*/
#define PRAGMASIZE 20
static void skipspace(LexState *LS) {
while (LS->current == ' ' || LS->current == '\t' || LS->current == '\r')
next(LS);
}
static int32 checkcond(char *buff) {
static const char *opts[] = { "nil", "1", nullptr };
int32 i = luaO_findstring(buff, opts);
if (i >= 0)
return i;
else if (Common::isAlpha((byte)buff[0]) || buff[0] == '_')
return luaS_globaldefined(buff);
else {
luaY_syntaxerror("invalid $if condition", buff);
return 0; // to avoid warnings
}
}
static void readname(LexState *LS, char *buff) {
int32 i = 0;
skipspace(LS);
while (Common::isAlnum(LS->current) || LS->current == '_') {
if (i >= PRAGMASIZE) {
buff[PRAGMASIZE] = 0;
luaY_syntaxerror("pragma too long", buff);
}
buff[i++] = LS->current;
next(LS);
}
buff[i] = 0;
}
static void inclinenumber (LexState *LS);
static void ifskip (LexState *LS) {
while (LS->ifstate[LS->iflevel].skip) {
if (LS->current == '\n')
inclinenumber(LS);
else if (LS->current == EOZ)
luaY_syntaxerror("input ends inside a $if", "");
else
next(LS);
}
}
static void inclinenumber (LexState *LS) {
static const char *pragmas [] =
{ "debug", "nodebug", "endinput", "end", "ifnot", "if", "else", nullptr };
next(LS); // skip '\n'
++LS->linenumber;
if (LS->current == '$') { // is a pragma?
char buff[PRAGMASIZE + 1];
int32 ifnot = 0;
int32 skip = LS->ifstate[LS->iflevel].skip;
next(LS); // skip $
readname(LS, buff);
switch (luaO_findstring(buff, pragmas)) {
case 0: // debug
if (!skip)
lua_debug = 1;
break;
case 1: // nodebug
if (!skip)
lua_debug = 0;
break;
case 2: // endinput
if (!skip) {
LS->current = EOZ;
LS->iflevel = 0; // to allow $endinput inside a $if
}
break;
case 3: // end
if (LS->iflevel-- == 0)
luaY_syntaxerror("unmatched $end", "$end");
break;
case 4: // ifnot
ifnot = 1;
// fall through
case 5: // if
if (LS->iflevel == MAX_IFS - 1)
luaY_syntaxerror("too many nested $ifs", "$if");
readname(LS, buff);
LS->iflevel++;
LS->ifstate[LS->iflevel].elsepart = 0;
LS->ifstate[LS->iflevel].condition = checkcond(buff) ? !ifnot : ifnot;
LS->ifstate[LS->iflevel].skip = skip || !LS->ifstate[LS->iflevel].condition;
break;
case 6: // else
if (LS->ifstate[LS->iflevel].elsepart)
luaY_syntaxerror("unmatched $else", "$else");
LS->ifstate[LS->iflevel].elsepart = 1;
LS->ifstate[LS->iflevel].skip = LS->ifstate[LS->iflevel - 1].skip || LS->ifstate[LS->iflevel].condition;
break;
default:
luaY_syntaxerror("unknown pragma", buff);
}
skipspace(LS);
if (LS->current == '\n') // pragma must end with a '\n' ...
inclinenumber(LS);
else if (LS->current != EOZ) // or eof
luaY_syntaxerror("invalid pragma format", buff);
ifskip(LS);
}
}
/*
** =======================================================
** LEXICAL ANALIZER
** =======================================================
*/
#define save(c) luaL_addchar(c)
#define save_and_next(LS) (save(LS->current), next(LS))
char *luaX_lasttoken() {
save(0);
return luaL_buffer();
}
static int read_long_string(LexState *LS, YYSTYPE *l) {
int cont = 0;
while (1) {
switch (LS->current) {
case EOZ:
save(0);
return WRONGTOKEN;
case '[':
save_and_next(LS);
if (LS->current == '[') {
cont++;
save_and_next(LS);
}
continue;
case ']':
save_and_next(LS);
if (LS->current == ']') {
if (cont == 0)
goto endloop;
cont--;
save_and_next(LS);
}
continue;
case '\n':
save('\n');
inclinenumber(LS);
continue;
default:
save_and_next(LS);
}
}
endloop:
save_and_next(LS); // pass the second ']'
Mbuffer[Mbuffnext - 2] = 0; // erases ']]'
l->pTStr = luaS_new(Mbuffbase + 2);
Mbuffer[Mbuffnext - 2] = ']'; // restores ']]'
return STRING;
}
/* to avoid warnings; this declaration cannot be public since YYSTYPE
** cannot be visible in llex.h (otherwise there is an error, since
** the parser body redefines it!)
*/
int32 luaY_lex(YYSTYPE *l);
int32 luaY_lex(YYSTYPE *l) {
LexState *LS = lua_state->lexstate;
double a;
luaL_resetbuffer();
if (lua_debug)
luaY_codedebugline(LS->linelasttoken);
LS->linelasttoken = LS->linenumber;
while (1) {
switch (LS->current) {
case ' ':
case '\t':
case '\r': // CR: to avoid problems with DOS
next(LS);
continue;
case '\n':
inclinenumber(LS);
LS->linelasttoken = LS->linenumber;
continue;
case '-':
save_and_next(LS);
if (LS->current != '-')
return '-';
do {
next(LS);
} while (LS->current != '\n' && LS->current != EOZ);
luaL_resetbuffer();
continue;
case '[':
save_and_next(LS);
if (LS->current != '[')
return '[';
else {
save_and_next(LS); // pass the second '['
return read_long_string(LS, l);
}
case '=':
save_and_next(LS);
if (LS->current != '=')
return '=';
else {
save_and_next(LS);
return EQ;
}
case '<':
save_and_next(LS);
if (LS->current != '=')
return '<';
else {
save_and_next(LS);
return LE;
}
case '>':
save_and_next(LS);
if (LS->current != '=')
return '>';
else {
save_and_next(LS);
return GE;
}
case '~':
save_and_next(LS);
if (LS->current != '=')
return '~';
else {
save_and_next(LS);
return NE;
}
case '"':
case '\'':
{
int32 del = LS->current;
save_and_next(LS);
while (LS->current != del) {
switch (LS->current) {
case EOZ:
case '\n':
save(0);
return WRONGTOKEN;
case '\\':
next(LS); // do not save the '\'
switch (LS->current) {
case 'n':
save('\n');
next(LS);
break;
case 't':
save('\t');
next(LS);
break;
case 'r':
save('\r');
next(LS);
break;
case '\n':
save('\n');
inclinenumber(LS);
break;
default :
save_and_next(LS); break;
}
break;
default:
save_and_next(LS);
}
}
next(LS); // skip delimiter
save(0);
l->pTStr = luaS_new(Mbuffbase + 1);
Mbuffer[Mbuffnext - 1] = del; // restore delimiter
return STRING;
}
case '.':
save_and_next(LS);
if (LS->current == '.') {
save_and_next(LS);
if (LS->current == '.') {
save_and_next(LS);
return DOTS; // ...
} else
return CONC; // ..
} else if (!Common::isDigit(LS->current))
return '.';
// LS->current is a digit: goes through to number/
a = 0.0;
goto fraction;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
a = 0.0;
do {
a = 10.0 * a + (LS->current - '0');
save_and_next(LS);
} while (Common::isDigit(LS->current));
if (LS->current == '.') {
save_and_next(LS);
if (LS->current == '.') {
save(0);
luaY_error("ambiguous syntax (decimal point x string concatenation)");
}
}
fraction:
{
double da = 0.1;
while (Common::isDigit(LS->current)) {
a += (LS->current - '0') * da;
da /= 10.0;
save_and_next(LS);
}
if (toupper(LS->current) == 'E') {
int32 e = 0;
int32 neg;
double ea;
save_and_next(LS);
neg = (LS->current == '-');
if (LS->current == '+' || LS->current == '-')
save_and_next(LS);
if (!Common::isDigit(LS->current)) {
save(0);
return WRONGTOKEN;
}
do {
e = 10 * e + (LS->current - '0');
save_and_next(LS);
} while (Common::isDigit(LS->current));
for (ea = neg ? 0.1 : 10.0; e > 0; e >>= 1) {
if (e & 1)
a *= ea;
ea *= ea;
}
}
l->vReal = a;
return NUMBER;
}
case EOZ:
save(0);
if (LS->iflevel > 0)
luaY_syntaxerror("input ends inside a $if", "");
return 0;
default:
if (LS->current != '_' && !Common::isAlpha(LS->current)) {
int32 c = LS->current;
save_and_next(LS);
return c;
} else { // identifier or reserved word
TaggedString *ts;
do {
save_and_next(LS);
} while (Common::isAlnum(LS->current) || LS->current == '_');
save(0);
ts = luaS_new(Mbuffbase);
if (ts->head.marked >= 255)
return ts->head.marked; // reserved word
l->pTStr = ts;
return NAME;
}
}
}
}
} // end of namespace Grim