lua/lua.stx
1997-08-04 16:15:05 -03:00

844 lines
18 KiB
Plaintext

%{
char *rcs_luastx = "$Id: lua.stx,v 3.50 1997/07/31 20:46:59 roberto Exp roberto $";
#include <stdlib.h>
#include "luadebug.h"
#include "luamem.h"
#include "lex.h"
#include "opcode.h"
#include "hash.h"
#include "inout.h"
#include "tree.h"
#include "table.h"
#include "lua.h"
#include "func.h"
/* to avoid warnings generated by yacc */
int yyparse (void);
#define malloc luaI_malloc
#define realloc luaI_realloc
#define free luaI_free
#ifndef LISTING
#define LISTING 0
#endif
#ifndef CODE_BLOCK
#define CODE_BLOCK 1000
#endif
#define MAXLOCALS 32
/* state needed to generate code for a given function */
struct State {
TFunc *f; /* current function header */
int codesize;
int pc; /* next position to code */
TaggedString *localvar[MAXLOCALS]; /* store local variable names */
int nlocalvar; /* number of active local variables */
int maxconsts; /* size of consts vector */
int nvars; /* total number of local variables (for debugging information) */
int maxvars; /* = -1 if no debug information */
} stateMain, stateFunc, *currState;
#define MAXVAR 32
static Long varbuffer[MAXVAR]; /* variables in an assignment list;
it's long to store negative Word values */
static int nvarbuffer=0; /* number of variables at a list */
int lua_debug = 0;
/* Internal functions */
static void yyerror (char *s)
{
luaI_syntaxerror(s);
}
static void check_space (int i)
{
if (currState->pc+i >= currState->codesize)
currState->codesize = growvector(&currState->f->code, currState->codesize,
Byte, codeEM, MAX_INT);
}
static void code_byte (Byte c)
{
check_space(1);
currState->f->code[currState->pc++] = c;
}
static void code_word_at (int pc, int n)
{
Word w = n;
if (w != n)
yyerror("block too big");
currState->f->code[pc] = n&0xFF;
currState->f->code[pc+1] = n>>8;
}
static void code_word (int n)
{
code_byte(n&0xFF);
code_byte(n>>8);
}
static void code_constant (int c)
{
if (c <= 255) {
code_byte(PUSHCONSTANTB);
code_byte(c);
}
else {
code_byte(PUSHCONSTANT);
code_word(c);
}
}
static int next_constant (void)
{
TFunc *f = currState->f;
if (f->nconsts >= currState->maxconsts) {
currState->maxconsts =
growvector(&f->consts, currState->maxconsts, TObject,
constantEM, MAX_WORD);
}
return f->nconsts++;
}
static int string_constant (TaggedString *s)
{
TFunc *f = currState->f;
int c = s->u.s.constindex;
if (!(0 <= c && c < f->nconsts &&
ttype(&f->consts[c]) == LUA_T_STRING && tsvalue(&f->consts[c]) == s)) {
c = next_constant();
ttype(&f->consts[c]) = LUA_T_STRING;
tsvalue(&f->consts[c]) = s;
s->u.s.constindex = c; /* hint for next time */
}
luaI_releasestring(s);
return c;
}
static void code_string (TaggedString *s)
{
code_constant(string_constant(s));
}
#define LIM 10
static int real_constant (real r)
{
/* check whether 'r' has appeared within the last LIM entries */
TObject *cnt = currState->f->consts;
int c = currState->f->nconsts;
int lim = c < LIM ? 0 : c-LIM;
while (--c >= lim) {
if (ttype(&cnt[c]) == LUA_T_NUMBER && nvalue(&cnt[c]) == r)
return c;
}
/* not found; create a new entry */
c = next_constant();
cnt = currState->f->consts; /* 'next_constant' may reallocate this vector */
ttype(&cnt[c]) = LUA_T_NUMBER;
nvalue(&cnt[c]) = r;
return c;
}
static void code_number (real f)
{
Word i;
if (f >= 0 && f <= (real)MAX_WORD && (real)(i=(Word)f) == f) {
/* f has an (short) integer value */
if (i <= 2) code_byte(PUSH0 + i);
else if (i <= 255) {
code_byte(PUSHBYTE);
code_byte(i);
}
else {
code_byte(PUSHWORD);
code_word(i);
}
}
else
code_constant(real_constant(f));
}
static void flush_record (int n)
{
if (n == 0) return;
code_byte(STOREMAP);
code_byte(n);
}
static void flush_list (int m, int n)
{
if (n == 0) return;
if (m == 0)
code_byte(STORELIST0);
else
if (m < 255)
{
code_byte(STORELIST);
code_byte(m);
}
else
yyerror ("list constructor too long");
code_byte(n);
}
static void luaI_registerlocalvar (TaggedString *varname, int line)
{
if (currState->maxvars != -1) { /* debug information? */
if (currState->nvars >= currState->maxvars)
currState->maxvars = growvector(&currState->f->locvars,
currState->maxvars, LocVar, "", MAX_WORD);
currState->f->locvars[currState->nvars].varname = varname;
currState->f->locvars[currState->nvars].line = line;
currState->nvars++;
}
}
static void luaI_unregisterlocalvar (int line)
{
luaI_registerlocalvar(NULL, line);
}
static void store_localvar (TaggedString *name, int n)
{
luaI_fixstring(name); /* local var names cannot be GC */
if (currState->nlocalvar+n < MAXLOCALS)
currState->localvar[currState->nlocalvar+n] = name;
else
yyerror ("too many local variables");
luaI_registerlocalvar(name, lua_linenumber);
}
static void add_localvar (TaggedString *name)
{
store_localvar(name, 0);
currState->nlocalvar++;
}
static void add_varbuffer (Long var)
{
if (nvarbuffer < MAXVAR)
varbuffer[nvarbuffer++] = var;
else
yyerror ("variable buffer overflow");
}
/*
** Search a local name and if find return its index. If do not find return -1
*/
static int lua_localname (TaggedString *n)
{
int i;
for (i=currState->nlocalvar-1; i >= 0; i--)
if (n == currState->localvar[i]) return i; /* local var */
return -1; /* global var */
}
/*
** Push a variable given a number. If number is positive, push global variable
** indexed by (number -1). If negative, push local indexed by ABS(number)-1.
** Otherwise, if zero, push indexed variable (record).
*/
static void lua_pushvar (Long number)
{
if (number > 0) /* global var */
{
code_byte(PUSHGLOBAL);
code_word(number-1);
}
else if (number < 0) /* local var */
{
number = (-number) - 1;
if (number < 10) code_byte(PUSHLOCAL0 + number);
else
{
code_byte(PUSHLOCAL);
code_byte(number);
}
}
else
{
code_byte(PUSHINDEXED);
}
}
static void lua_codeadjust (int n)
{
n += currState->nlocalvar;
if (n == 0)
code_byte(ADJUST0);
else {
code_byte(ADJUST);
code_byte(n);
}
}
void luaI_codedebugline (int line)
{
static int lastline = 0;
if (lua_debug && line != lastline)
{
code_byte(SETLINE);
code_word(line);
lastline = line;
}
}
static int adjust_functioncall (Long exp, int i)
{
if (exp <= 0)
return -exp; /* exp is -list length */
else {
int temp = currState->f->code[exp];
currState->f->code[exp] = i;
return temp+i;
}
}
static void adjust_mult_assign (int vars, Long exps, int temps)
{
if (exps > 0) { /* must correct function call */
int diff = vars - currState->f->code[exps];
if (diff >= 0)
adjust_functioncall(exps, diff);
else {
adjust_functioncall(exps, 0);
lua_codeadjust(temps);
}
}
else if (vars != -exps)
lua_codeadjust(temps);
}
static int close_parlist (int dots)
{
if (!dots)
lua_codeadjust(0);
else {
code_byte(VARARGS);
code_byte(currState->nlocalvar);
add_localvar(luaI_createstring("arg"));
}
return lua_linenumber;
}
static void storesinglevar (Long v)
{
if (v > 0) /* global var */
{
code_byte(STOREGLOBAL);
code_word(v-1);
}
else if (v < 0) /* local var */
{
int number = (-v) - 1;
if (number < 10) code_byte(STORELOCAL0 + number);
else
{
code_byte(STORELOCAL);
code_byte(number);
}
}
else
code_byte(STOREINDEXED0);
}
static void lua_codestore (int i)
{
if (varbuffer[i] != 0) /* global or local var */
storesinglevar(varbuffer[i]);
else /* indexed var */
{
int j;
int upper=0; /* number of indexed variables upper */
int param; /* number of itens until indexed expression */
for (j=i+1; j <nvarbuffer; j++)
if (varbuffer[j] == 0) upper++;
param = upper*2 + i;
if (param == 0)
code_byte(STOREINDEXED0);
else
{
code_byte(STOREINDEXED);
code_byte(param);
}
}
}
static void codeIf (Long thenAdd, Long elseAdd)
{
Long elseinit = elseAdd+sizeof(Word)+1;
if (currState->pc == elseinit) { /* no else */
currState->pc -= sizeof(Word)+1;
elseinit = currState->pc;
}
else {
currState->f->code[elseAdd] = JMP;
code_word_at(elseAdd+1, currState->pc-elseinit);
}
currState->f->code[thenAdd] = IFFJMP;
code_word_at(thenAdd+1, elseinit-(thenAdd+sizeof(Word)+1));
}
static void code_shortcircuit (int pc, Byte jmp)
{
currState->f->code[pc] = jmp;
code_word_at(pc+1, currState->pc - (pc + sizeof(Word)+1));
}
static void init_state (TFunc *f)
{
currState->nlocalvar = 0;
currState->f = f;
currState->pc = 0;
currState->codesize = CODE_BLOCK;
f->code = newvector(CODE_BLOCK, Byte);
currState->maxconsts = 0;
if (lua_debug) {
currState->nvars = 0;
currState->maxvars = 0;
}
else
currState->maxvars = -1; /* flag no debug information */
}
static void init_func (Long v)
{
TFunc *f = new(TFunc);
int c = next_constant();
ttype(&currState->f->consts[c]) = LUA_T_FUNCTION;
currState->f->consts[c].value.tf = f;
code_constant(c);
storesinglevar(v);
currState = &stateFunc;
luaI_initTFunc(f);
init_state(f);
luaI_codedebugline(lua_linenumber);
}
static void codereturn (void)
{
if (currState->nlocalvar == 0)
code_byte(RETCODE0);
else
{
code_byte(RETCODE);
code_byte(currState->nlocalvar);
}
}
static void close_func (void)
{
codereturn();
code_byte(ENDCODE);
currState->f->code = shrinkvector(currState->f->code, currState->pc, Byte);
currState->f->consts = shrinkvector(currState->f->consts,
currState->f->nconsts, TObject);
if (currState->maxvars != -1) { /* debug information? */
luaI_registerlocalvar(NULL, -1); /* flag end of vector */
currState->f->locvars = shrinkvector(currState->f->locvars,
currState->nvars, LocVar);
}
}
/*
** Parse LUA code.
*/
void lua_parse (TFunc *tf)
{
currState = &stateMain;
init_state(tf);
if (yyparse ()) lua_error("parse error");
currState = &stateMain;
close_func();
}
%}
%union
{
int vInt;
real vReal;
char *pChar;
Long vLong;
TaggedString *pTStr;
}
%start chunk
%token WRONGTOKEN
%token NIL
%token IF THEN ELSE ELSEIF WHILE DO REPEAT UNTIL END
%token RETURN
%token LOCAL
%token FUNCTION
%token DOTS
%token <vReal> NUMBER
%token <pTStr> NAME STRING
%type <vLong> PrepJump
%type <vLong> exprlist, exprlist1 /* if > 0, points to function return
counter (which has list length); if <= 0, -list lenght */
%type <vLong> functioncall, expr /* if != 0, points to function return
counter */
%type <vInt> varlist1, funcParams, funcvalue
%type <vInt> fieldlist, localdeclist, decinit
%type <vInt> ffieldlist, ffieldlist1, semicolonpart
%type <vInt> lfieldlist, lfieldlist1
%type <vInt> parlist, parlist1, par
%type <vLong> var, singlevar
%left AND OR
%left EQ NE '>' '<' LE GE
%left CONC
%left '+' '-'
%left '*' '/'
%left UNARY NOT
%right '^'
%% /* beginning of rules section */
chunk : chunklist ret ;
chunklist : /* empty */
| chunklist stat sc
| chunklist function
;
function : FUNCTION funcname body
;
funcname : var { init_func($1); }
| varexp ':' NAME
{
code_string($3);
init_func(0); /* indexed variable */
add_localvar(luaI_createstring("self"));
}
;
body : '(' parlist ')' block END
{
close_func();
currState->f->lineDefined = $2;
currState = &stateMain; /* change back to main code */
}
;
statlist : /* empty */
| statlist stat sc
;
sc : /* empty */ | ';' ;
stat : IF expr1 THEN PrepJump block PrepJump elsepart END
{ codeIf($4, $6); }
| WHILE {$<vLong>$=currState->pc;} expr1 DO PrepJump block PrepJump END
{
currState->f->code[$5] = IFFJMP;
code_word_at($5+1, currState->pc - ($5+sizeof(Word)+1));
currState->f->code[$7] = UPJMP;
code_word_at($7+1, currState->pc - ($<vLong>2));
}
| REPEAT {$<vLong>$=currState->pc;} block UNTIL expr1 PrepJump
{
currState->f->code[$6] = IFFUPJMP;
code_word_at($6+1, currState->pc - ($<vLong>2));
}
| varlist1 '=' exprlist1
{
{
int i;
adjust_mult_assign(nvarbuffer, $3, $1 * 2 + nvarbuffer);
for (i=nvarbuffer-1; i>=0; i--)
lua_codestore(i);
if ($1 > 1 || ($1 == 1 && varbuffer[0] != 0))
lua_codeadjust(0);
}
}
| functioncall {;}
| LOCAL localdeclist decinit
{ currState->nlocalvar += $2;
adjust_mult_assign($2, $3, 0);
}
;
elsepart : /* empty */
| ELSE block
| ELSEIF expr1 THEN PrepJump block PrepJump elsepart
{ codeIf($4, $6); }
;
block : {$<vInt>$ = currState->nlocalvar;} statlist ret
{
if (currState->nlocalvar != $<vInt>1) {
for (; currState->nlocalvar > $<vInt>1; currState->nlocalvar--)
luaI_unregisterlocalvar(lua_linenumber);
lua_codeadjust(0);
}
}
;
ret : /* empty */
| RETURN exprlist sc
{
adjust_functioncall($2, MULT_RET);
codereturn();
}
;
PrepJump : /* empty */
{
$$ = currState->pc;
code_byte(0); /* open space */
code_word(0);
}
;
expr1 : expr { adjust_functioncall($1, 1); }
;
expr : '(' expr ')' { $$ = $2; }
| expr1 EQ expr1 { code_byte(EQOP); $$ = 0; }
| expr1 '<' expr1 { code_byte(LTOP); $$ = 0; }
| expr1 '>' expr1 { code_byte(GTOP); $$ = 0; }
| expr1 NE expr1 { code_byte(EQOP); code_byte(NOTOP); $$ = 0; }
| expr1 LE expr1 { code_byte(LEOP); $$ = 0; }
| expr1 GE expr1 { code_byte(GEOP); $$ = 0; }
| expr1 '+' expr1 { code_byte(ADDOP); $$ = 0; }
| expr1 '-' expr1 { code_byte(SUBOP); $$ = 0; }
| expr1 '*' expr1 { code_byte(MULTOP); $$ = 0; }
| expr1 '/' expr1 { code_byte(DIVOP); $$ = 0; }
| expr1 '^' expr1 { code_byte(POWOP); $$ = 0; }
| expr1 CONC expr1 { code_byte(CONCOP); $$ = 0; }
| '-' expr1 %prec UNARY { code_byte(MINUSOP); $$ = 0;}
| table { $$ = 0; }
| varexp { $$ = 0;}
| NUMBER { code_number($1); $$ = 0; }
| STRING
{
code_string($1);
$$ = 0;
}
| NIL {code_byte(PUSHNIL); $$ = 0; }
| functioncall { $$ = $1; }
| NOT expr1 { code_byte(NOTOP); $$ = 0;}
| expr1 AND PrepJump expr1
{
code_shortcircuit($3, ONFJMP);
$$ = 0;
}
| expr1 OR PrepJump expr1
{
code_shortcircuit($3, ONTJMP);
$$ = 0;
}
;
table :
{
code_byte(CREATEARRAY);
$<vLong>$ = currState->pc; code_word(0);
}
'{' fieldlist '}'
{
code_word_at($<vLong>1, $3);
}
;
functioncall : funcvalue funcParams
{
code_byte(CALLFUNC);
code_byte($1+$2);
$$ = currState->pc;
code_byte(0); /* may be modified by other rules */
}
;
funcvalue : varexp { $$ = 0; }
| varexp ':' NAME
{
code_byte(PUSHSELF);
code_word(string_constant($3));
$$ = 1;
}
;
funcParams : '(' exprlist ')'
{ $$ = adjust_functioncall($2, 1); }
| table { $$ = 1; }
;
exprlist : /* empty */ { $$ = 0; }
| exprlist1 { $$ = $1; }
;
exprlist1 : expr { if ($1 != 0) $$ = $1; else $$ = -1; }
| exprlist1 ',' { $<vLong>$ = adjust_functioncall($1, 1); } expr
{
if ($4 == 0) $$ = -($<vLong>3 + 1); /* -length */
else
{
adjust_functioncall($4, $<vLong>3);
$$ = $4;
}
}
;
parlist : /* empty */ { $$ = close_parlist(0); }
| parlist1 { $$ = close_parlist($1); }
;
parlist1 : par { $$ = $1; }
| parlist1 ',' par
{
if ($1)
lua_error("invalid parameter list");
$$ = $3;
}
;
par : NAME { add_localvar($1); $$ = 0; }
| DOTS { $$ = 1; }
;
fieldlist : lfieldlist
{ flush_list($1/FIELDS_PER_FLUSH, $1%FIELDS_PER_FLUSH); }
semicolonpart
{ $$ = $1+$3; }
| ffieldlist1 lastcomma
{ $$ = $1; flush_record($1%FIELDS_PER_FLUSH); }
;
semicolonpart : /* empty */
{ $$ = 0; }
| ';' ffieldlist
{ $$ = $2; flush_record($2%FIELDS_PER_FLUSH); }
;
lastcomma : /* empty */
| ','
;
ffieldlist : /* empty */ { $$ = 0; }
| ffieldlist1 lastcomma { $$ = $1; }
;
ffieldlist1 : ffield {$$=1;}
| ffieldlist1 ',' ffield
{
$$=$1+1;
if ($$%FIELDS_PER_FLUSH == 0) flush_record(FIELDS_PER_FLUSH);
}
;
ffield : ffieldkey '=' expr1
;
ffieldkey : '[' expr1 ']'
| NAME { code_string($1); }
;
lfieldlist : /* empty */ { $$ = 0; }
| lfieldlist1 lastcomma { $$ = $1; }
;
lfieldlist1 : expr1 {$$=1;}
| lfieldlist1 ',' expr1
{
$$=$1+1;
if ($$%FIELDS_PER_FLUSH == 0)
flush_list($$/FIELDS_PER_FLUSH - 1, FIELDS_PER_FLUSH);
}
;
varlist1 : var
{
nvarbuffer = 0;
add_varbuffer($1);
$$ = ($1 == 0) ? 1 : 0;
}
| varlist1 ',' var
{
add_varbuffer($3);
$$ = ($3 == 0) ? $1 + 1 : $1;
}
;
var : singlevar { $$ = $1; }
| varexp '[' expr1 ']'
{
$$ = 0; /* indexed variable */
}
| varexp '.' NAME
{
code_string($3);
$$ = 0; /* indexed variable */
}
;
singlevar : NAME
{
int local = lua_localname($1);
if (local == -1) /* global var */
$$ = luaI_findsymbol($1)+1; /* return positive value */
else
$$ = -(local+1); /* return negative value */
luaI_fixstring($1); /* cannot GC variable names */
}
;
varexp : var { lua_pushvar($1); }
;
localdeclist : NAME {store_localvar($1, 0); $$ = 1;}
| localdeclist ',' NAME
{
store_localvar($3, $1);
$$ = $1+1;
}
;
decinit : /* empty */ { $$ = 0; }
| '=' exprlist1 { $$ = $2; }
;
%%