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Diffstat (limited to 'fluent-bit/lib/luajit-3065c9/src/lj_parse.c')
| -rw-r--r-- | fluent-bit/lib/luajit-3065c9/src/lj_parse.c | 2747 |
1 files changed, 2747 insertions, 0 deletions
diff --git a/fluent-bit/lib/luajit-3065c9/src/lj_parse.c b/fluent-bit/lib/luajit-3065c9/src/lj_parse.c new file mode 100644 index 00000000..9ddf60ed --- /dev/null +++ b/fluent-bit/lib/luajit-3065c9/src/lj_parse.c @@ -0,0 +1,2747 @@ +/* +** Lua parser (source code -> bytecode). +** Copyright (C) 2005-2022 Mike Pall. See Copyright Notice in luajit.h +** +** Major portions taken verbatim or adapted from the Lua interpreter. +** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h +*/ + +#define lj_parse_c +#define LUA_CORE + +#include "lj_obj.h" +#include "lj_gc.h" +#include "lj_err.h" +#include "lj_debug.h" +#include "lj_buf.h" +#include "lj_str.h" +#include "lj_tab.h" +#include "lj_func.h" +#include "lj_state.h" +#include "lj_bc.h" +#if LJ_HASFFI +#include "lj_ctype.h" +#endif +#include "lj_strfmt.h" +#include "lj_lex.h" +#include "lj_parse.h" +#include "lj_vm.h" +#include "lj_vmevent.h" + +/* -- Parser structures and definitions ----------------------------------- */ + +/* Expression kinds. */ +typedef enum { + /* Constant expressions must be first and in this order: */ + VKNIL, + VKFALSE, + VKTRUE, + VKSTR, /* sval = string value */ + VKNUM, /* nval = number value */ + VKLAST = VKNUM, + VKCDATA, /* nval = cdata value, not treated as a constant expression */ + /* Non-constant expressions follow: */ + VLOCAL, /* info = local register, aux = vstack index */ + VUPVAL, /* info = upvalue index, aux = vstack index */ + VGLOBAL, /* sval = string value */ + VINDEXED, /* info = table register, aux = index reg/byte/string const */ + VJMP, /* info = instruction PC */ + VRELOCABLE, /* info = instruction PC */ + VNONRELOC, /* info = result register */ + VCALL, /* info = instruction PC, aux = base */ + VVOID +} ExpKind; + +/* Expression descriptor. */ +typedef struct ExpDesc { + union { + struct { + uint32_t info; /* Primary info. */ + uint32_t aux; /* Secondary info. */ + } s; + TValue nval; /* Number value. */ + GCstr *sval; /* String value. */ + } u; + ExpKind k; + BCPos t; /* True condition jump list. */ + BCPos f; /* False condition jump list. */ +} ExpDesc; + +/* Macros for expressions. */ +#define expr_hasjump(e) ((e)->t != (e)->f) + +#define expr_isk(e) ((e)->k <= VKLAST) +#define expr_isk_nojump(e) (expr_isk(e) && !expr_hasjump(e)) +#define expr_isnumk(e) ((e)->k == VKNUM) +#define expr_isnumk_nojump(e) (expr_isnumk(e) && !expr_hasjump(e)) +#define expr_isstrk(e) ((e)->k == VKSTR) + +#define expr_numtv(e) check_exp(expr_isnumk((e)), &(e)->u.nval) +#define expr_numberV(e) numberVnum(expr_numtv((e))) + +/* Initialize expression. */ +static LJ_AINLINE void expr_init(ExpDesc *e, ExpKind k, uint32_t info) +{ + e->k = k; + e->u.s.info = info; + e->f = e->t = NO_JMP; +} + +/* Check number constant for +-0. */ +static int expr_numiszero(ExpDesc *e) +{ + TValue *o = expr_numtv(e); + return tvisint(o) ? (intV(o) == 0) : tviszero(o); +} + +/* Per-function linked list of scope blocks. */ +typedef struct FuncScope { + struct FuncScope *prev; /* Link to outer scope. */ + MSize vstart; /* Start of block-local variables. */ + uint8_t nactvar; /* Number of active vars outside the scope. */ + uint8_t flags; /* Scope flags. */ +} FuncScope; + +#define FSCOPE_LOOP 0x01 /* Scope is a (breakable) loop. */ +#define FSCOPE_BREAK 0x02 /* Break used in scope. */ +#define FSCOPE_GOLA 0x04 /* Goto or label used in scope. */ +#define FSCOPE_UPVAL 0x08 /* Upvalue in scope. */ +#define FSCOPE_NOCLOSE 0x10 /* Do not close upvalues. */ + +#define NAME_BREAK ((GCstr *)(uintptr_t)1) + +/* Index into variable stack. */ +typedef uint16_t VarIndex; +#define LJ_MAX_VSTACK (65536 - LJ_MAX_UPVAL) + +/* Variable/goto/label info. */ +#define VSTACK_VAR_RW 0x01 /* R/W variable. */ +#define VSTACK_GOTO 0x02 /* Pending goto. */ +#define VSTACK_LABEL 0x04 /* Label. */ + +/* Per-function state. */ +typedef struct FuncState { + GCtab *kt; /* Hash table for constants. */ + LexState *ls; /* Lexer state. */ + lua_State *L; /* Lua state. */ + FuncScope *bl; /* Current scope. */ + struct FuncState *prev; /* Enclosing function. */ + BCPos pc; /* Next bytecode position. */ + BCPos lasttarget; /* Bytecode position of last jump target. */ + BCPos jpc; /* Pending jump list to next bytecode. */ + BCReg freereg; /* First free register. */ + BCReg nactvar; /* Number of active local variables. */ + BCReg nkn, nkgc; /* Number of lua_Number/GCobj constants */ + BCLine linedefined; /* First line of the function definition. */ + BCInsLine *bcbase; /* Base of bytecode stack. */ + BCPos bclim; /* Limit of bytecode stack. */ + MSize vbase; /* Base of variable stack for this function. */ + uint8_t flags; /* Prototype flags. */ + uint8_t numparams; /* Number of parameters. */ + uint8_t framesize; /* Fixed frame size. */ + uint8_t nuv; /* Number of upvalues */ + VarIndex varmap[LJ_MAX_LOCVAR]; /* Map from register to variable idx. */ + VarIndex uvmap[LJ_MAX_UPVAL]; /* Map from upvalue to variable idx. */ + VarIndex uvtmp[LJ_MAX_UPVAL]; /* Temporary upvalue map. */ +} FuncState; + +/* Binary and unary operators. ORDER OPR */ +typedef enum BinOpr { + OPR_ADD, OPR_SUB, OPR_MUL, OPR_DIV, OPR_MOD, OPR_POW, /* ORDER ARITH */ + OPR_CONCAT, + OPR_NE, OPR_EQ, + OPR_LT, OPR_GE, OPR_LE, OPR_GT, + OPR_AND, OPR_OR, + OPR_NOBINOPR +} BinOpr; + +LJ_STATIC_ASSERT((int)BC_ISGE-(int)BC_ISLT == (int)OPR_GE-(int)OPR_LT); +LJ_STATIC_ASSERT((int)BC_ISLE-(int)BC_ISLT == (int)OPR_LE-(int)OPR_LT); +LJ_STATIC_ASSERT((int)BC_ISGT-(int)BC_ISLT == (int)OPR_GT-(int)OPR_LT); +LJ_STATIC_ASSERT((int)BC_SUBVV-(int)BC_ADDVV == (int)OPR_SUB-(int)OPR_ADD); +LJ_STATIC_ASSERT((int)BC_MULVV-(int)BC_ADDVV == (int)OPR_MUL-(int)OPR_ADD); +LJ_STATIC_ASSERT((int)BC_DIVVV-(int)BC_ADDVV == (int)OPR_DIV-(int)OPR_ADD); +LJ_STATIC_ASSERT((int)BC_MODVV-(int)BC_ADDVV == (int)OPR_MOD-(int)OPR_ADD); + +#ifdef LUA_USE_ASSERT +#define lj_assertFS(c, ...) (lj_assertG_(G(fs->L), (c), __VA_ARGS__)) +#else +#define lj_assertFS(c, ...) ((void)fs) +#endif + +/* -- Error handling ------------------------------------------------------ */ + +LJ_NORET LJ_NOINLINE static void err_syntax(LexState *ls, ErrMsg em) +{ + lj_lex_error(ls, ls->tok, em); +} + +LJ_NORET LJ_NOINLINE static void err_token(LexState *ls, LexToken tok) +{ + lj_lex_error(ls, ls->tok, LJ_ERR_XTOKEN, lj_lex_token2str(ls, tok)); +} + +LJ_NORET static void err_limit(FuncState *fs, uint32_t limit, const char *what) +{ + if (fs->linedefined == 0) + lj_lex_error(fs->ls, 0, LJ_ERR_XLIMM, limit, what); + else + lj_lex_error(fs->ls, 0, LJ_ERR_XLIMF, fs->linedefined, limit, what); +} + +#define checklimit(fs, v, l, m) if ((v) >= (l)) err_limit(fs, l, m) +#define checklimitgt(fs, v, l, m) if ((v) > (l)) err_limit(fs, l, m) +#define checkcond(ls, c, em) { if (!(c)) err_syntax(ls, em); } + +/* -- Management of constants --------------------------------------------- */ + +/* Return bytecode encoding for primitive constant. */ +#define const_pri(e) check_exp((e)->k <= VKTRUE, (e)->k) + +#define tvhaskslot(o) ((o)->u32.hi == 0) +#define tvkslot(o) ((o)->u32.lo) + +/* Add a number constant. */ +static BCReg const_num(FuncState *fs, ExpDesc *e) +{ + lua_State *L = fs->L; + TValue *o; + lj_assertFS(expr_isnumk(e), "bad usage"); + o = lj_tab_set(L, fs->kt, &e->u.nval); + if (tvhaskslot(o)) + return tvkslot(o); + o->u64 = fs->nkn; + return fs->nkn++; +} + +/* Add a GC object constant. */ +static BCReg const_gc(FuncState *fs, GCobj *gc, uint32_t itype) +{ + lua_State *L = fs->L; + TValue key, *o; + setgcV(L, &key, gc, itype); + /* NOBARRIER: the key is new or kept alive. */ + o = lj_tab_set(L, fs->kt, &key); + if (tvhaskslot(o)) + return tvkslot(o); + o->u64 = fs->nkgc; + return fs->nkgc++; +} + +/* Add a string constant. */ +static BCReg const_str(FuncState *fs, ExpDesc *e) +{ + lj_assertFS(expr_isstrk(e) || e->k == VGLOBAL, "bad usage"); + return const_gc(fs, obj2gco(e->u.sval), LJ_TSTR); +} + +/* Anchor string constant to avoid GC. */ +GCstr *lj_parse_keepstr(LexState *ls, const char *str, size_t len) +{ + /* NOBARRIER: the key is new or kept alive. */ + lua_State *L = ls->L; + GCstr *s = lj_str_new(L, str, len); + TValue *tv = lj_tab_setstr(L, ls->fs->kt, s); + if (tvisnil(tv)) setboolV(tv, 1); + lj_gc_check(L); + return s; +} + +#if LJ_HASFFI +/* Anchor cdata to avoid GC. */ +void lj_parse_keepcdata(LexState *ls, TValue *tv, GCcdata *cd) +{ + /* NOBARRIER: the key is new or kept alive. */ + lua_State *L = ls->L; + setcdataV(L, tv, cd); + setboolV(lj_tab_set(L, ls->fs->kt, tv), 1); +} +#endif + +/* -- Jump list handling -------------------------------------------------- */ + +/* Get next element in jump list. */ +static BCPos jmp_next(FuncState *fs, BCPos pc) +{ + ptrdiff_t delta = bc_j(fs->bcbase[pc].ins); + if ((BCPos)delta == NO_JMP) + return NO_JMP; + else + return (BCPos)(((ptrdiff_t)pc+1)+delta); +} + +/* Check if any of the instructions on the jump list produce no value. */ +static int jmp_novalue(FuncState *fs, BCPos list) +{ + for (; list != NO_JMP; list = jmp_next(fs, list)) { + BCIns p = fs->bcbase[list >= 1 ? list-1 : list].ins; + if (!(bc_op(p) == BC_ISTC || bc_op(p) == BC_ISFC || bc_a(p) == NO_REG)) + return 1; + } + return 0; +} + +/* Patch register of test instructions. */ +static int jmp_patchtestreg(FuncState *fs, BCPos pc, BCReg reg) +{ + BCInsLine *ilp = &fs->bcbase[pc >= 1 ? pc-1 : pc]; + BCOp op = bc_op(ilp->ins); + if (op == BC_ISTC || op == BC_ISFC) { + if (reg != NO_REG && reg != bc_d(ilp->ins)) { + setbc_a(&ilp->ins, reg); + } else { /* Nothing to store or already in the right register. */ + setbc_op(&ilp->ins, op+(BC_IST-BC_ISTC)); + setbc_a(&ilp->ins, 0); + } + } else if (bc_a(ilp->ins) == NO_REG) { + if (reg == NO_REG) { + ilp->ins = BCINS_AJ(BC_JMP, bc_a(fs->bcbase[pc].ins), 0); + } else { + setbc_a(&ilp->ins, reg); + if (reg >= bc_a(ilp[1].ins)) + setbc_a(&ilp[1].ins, reg+1); + } + } else { + return 0; /* Cannot patch other instructions. */ + } + return 1; +} + +/* Drop values for all instructions on jump list. */ +static void jmp_dropval(FuncState *fs, BCPos list) +{ + for (; list != NO_JMP; list = jmp_next(fs, list)) + jmp_patchtestreg(fs, list, NO_REG); +} + +/* Patch jump instruction to target. */ +static void jmp_patchins(FuncState *fs, BCPos pc, BCPos dest) +{ + BCIns *jmp = &fs->bcbase[pc].ins; + BCPos offset = dest-(pc+1)+BCBIAS_J; + lj_assertFS(dest != NO_JMP, "uninitialized jump target"); + if (offset > BCMAX_D) + err_syntax(fs->ls, LJ_ERR_XJUMP); + setbc_d(jmp, offset); +} + +/* Append to jump list. */ +static void jmp_append(FuncState *fs, BCPos *l1, BCPos l2) +{ + if (l2 == NO_JMP) { + return; + } else if (*l1 == NO_JMP) { + *l1 = l2; + } else { + BCPos list = *l1; + BCPos next; + while ((next = jmp_next(fs, list)) != NO_JMP) /* Find last element. */ + list = next; + jmp_patchins(fs, list, l2); + } +} + +/* Patch jump list and preserve produced values. */ +static void jmp_patchval(FuncState *fs, BCPos list, BCPos vtarget, + BCReg reg, BCPos dtarget) +{ + while (list != NO_JMP) { + BCPos next = jmp_next(fs, list); + if (jmp_patchtestreg(fs, list, reg)) + jmp_patchins(fs, list, vtarget); /* Jump to target with value. */ + else + jmp_patchins(fs, list, dtarget); /* Jump to default target. */ + list = next; + } +} + +/* Jump to following instruction. Append to list of pending jumps. */ +static void jmp_tohere(FuncState *fs, BCPos list) +{ + fs->lasttarget = fs->pc; + jmp_append(fs, &fs->jpc, list); +} + +/* Patch jump list to target. */ +static void jmp_patch(FuncState *fs, BCPos list, BCPos target) +{ + if (target == fs->pc) { + jmp_tohere(fs, list); + } else { + lj_assertFS(target < fs->pc, "bad jump target"); + jmp_patchval(fs, list, target, NO_REG, target); + } +} + +/* -- Bytecode register allocator ----------------------------------------- */ + +/* Bump frame size. */ +static void bcreg_bump(FuncState *fs, BCReg n) +{ + BCReg sz = fs->freereg + n; + if (sz > fs->framesize) { + if (sz >= LJ_MAX_SLOTS) + err_syntax(fs->ls, LJ_ERR_XSLOTS); + fs->framesize = (uint8_t)sz; + } +} + +/* Reserve registers. */ +static void bcreg_reserve(FuncState *fs, BCReg n) +{ + bcreg_bump(fs, n); + fs->freereg += n; +} + +/* Free register. */ +static void bcreg_free(FuncState *fs, BCReg reg) +{ + if (reg >= fs->nactvar) { + fs->freereg--; + lj_assertFS(reg == fs->freereg, "bad regfree"); + } +} + +/* Free register for expression. */ +static void expr_free(FuncState *fs, ExpDesc *e) +{ + if (e->k == VNONRELOC) + bcreg_free(fs, e->u.s.info); +} + +/* -- Bytecode emitter ---------------------------------------------------- */ + +/* Emit bytecode instruction. */ +static BCPos bcemit_INS(FuncState *fs, BCIns ins) +{ + BCPos pc = fs->pc; + LexState *ls = fs->ls; + jmp_patchval(fs, fs->jpc, pc, NO_REG, pc); + fs->jpc = NO_JMP; + if (LJ_UNLIKELY(pc >= fs->bclim)) { + ptrdiff_t base = fs->bcbase - ls->bcstack; + checklimit(fs, ls->sizebcstack, LJ_MAX_BCINS, "bytecode instructions"); + lj_mem_growvec(fs->L, ls->bcstack, ls->sizebcstack, LJ_MAX_BCINS,BCInsLine); + fs->bclim = (BCPos)(ls->sizebcstack - base); + fs->bcbase = ls->bcstack + base; + } + fs->bcbase[pc].ins = ins; + fs->bcbase[pc].line = ls->lastline; + fs->pc = pc+1; + return pc; +} + +#define bcemit_ABC(fs, o, a, b, c) bcemit_INS(fs, BCINS_ABC(o, a, b, c)) +#define bcemit_AD(fs, o, a, d) bcemit_INS(fs, BCINS_AD(o, a, d)) +#define bcemit_AJ(fs, o, a, j) bcemit_INS(fs, BCINS_AJ(o, a, j)) + +#define bcptr(fs, e) (&(fs)->bcbase[(e)->u.s.info].ins) + +/* -- Bytecode emitter for expressions ------------------------------------ */ + +/* Discharge non-constant expression to any register. */ +static void expr_discharge(FuncState *fs, ExpDesc *e) +{ + BCIns ins; + if (e->k == VUPVAL) { + ins = BCINS_AD(BC_UGET, 0, e->u.s.info); + } else if (e->k == VGLOBAL) { + ins = BCINS_AD(BC_GGET, 0, const_str(fs, e)); + } else if (e->k == VINDEXED) { + BCReg rc = e->u.s.aux; + if ((int32_t)rc < 0) { + ins = BCINS_ABC(BC_TGETS, 0, e->u.s.info, ~rc); + } else if (rc > BCMAX_C) { + ins = BCINS_ABC(BC_TGETB, 0, e->u.s.info, rc-(BCMAX_C+1)); + } else { + bcreg_free(fs, rc); + ins = BCINS_ABC(BC_TGETV, 0, e->u.s.info, rc); + } + bcreg_free(fs, e->u.s.info); + } else if (e->k == VCALL) { + e->u.s.info = e->u.s.aux; + e->k = VNONRELOC; + return; + } else if (e->k == VLOCAL) { + e->k = VNONRELOC; + return; + } else { + return; + } + e->u.s.info = bcemit_INS(fs, ins); + e->k = VRELOCABLE; +} + +/* Emit bytecode to set a range of registers to nil. */ +static void bcemit_nil(FuncState *fs, BCReg from, BCReg n) +{ + if (fs->pc > fs->lasttarget) { /* No jumps to current position? */ + BCIns *ip = &fs->bcbase[fs->pc-1].ins; + BCReg pto, pfrom = bc_a(*ip); + switch (bc_op(*ip)) { /* Try to merge with the previous instruction. */ + case BC_KPRI: + if (bc_d(*ip) != ~LJ_TNIL) break; + if (from == pfrom) { + if (n == 1) return; + } else if (from == pfrom+1) { + from = pfrom; + n++; + } else { + break; + } + *ip = BCINS_AD(BC_KNIL, from, from+n-1); /* Replace KPRI. */ + return; + case BC_KNIL: + pto = bc_d(*ip); + if (pfrom <= from && from <= pto+1) { /* Can we connect both ranges? */ + if (from+n-1 > pto) + setbc_d(ip, from+n-1); /* Patch previous instruction range. */ + return; + } + break; + default: + break; + } + } + /* Emit new instruction or replace old instruction. */ + bcemit_INS(fs, n == 1 ? BCINS_AD(BC_KPRI, from, VKNIL) : + BCINS_AD(BC_KNIL, from, from+n-1)); +} + +/* Discharge an expression to a specific register. Ignore branches. */ +static void expr_toreg_nobranch(FuncState *fs, ExpDesc *e, BCReg reg) +{ + BCIns ins; + expr_discharge(fs, e); + if (e->k == VKSTR) { + ins = BCINS_AD(BC_KSTR, reg, const_str(fs, e)); + } else if (e->k == VKNUM) { +#if LJ_DUALNUM + cTValue *tv = expr_numtv(e); + if (tvisint(tv) && checki16(intV(tv))) + ins = BCINS_AD(BC_KSHORT, reg, (BCReg)(uint16_t)intV(tv)); + else +#else + lua_Number n = expr_numberV(e); + int32_t k = lj_num2int(n); + if (checki16(k) && n == (lua_Number)k) + ins = BCINS_AD(BC_KSHORT, reg, (BCReg)(uint16_t)k); + else +#endif + ins = BCINS_AD(BC_KNUM, reg, const_num(fs, e)); +#if LJ_HASFFI + } else if (e->k == VKCDATA) { + fs->flags |= PROTO_FFI; + ins = BCINS_AD(BC_KCDATA, reg, + const_gc(fs, obj2gco(cdataV(&e->u.nval)), LJ_TCDATA)); +#endif + } else if (e->k == VRELOCABLE) { + setbc_a(bcptr(fs, e), reg); + goto noins; + } else if (e->k == VNONRELOC) { + if (reg == e->u.s.info) + goto noins; + ins = BCINS_AD(BC_MOV, reg, e->u.s.info); + } else if (e->k == VKNIL) { + bcemit_nil(fs, reg, 1); + goto noins; + } else if (e->k <= VKTRUE) { + ins = BCINS_AD(BC_KPRI, reg, const_pri(e)); + } else { + lj_assertFS(e->k == VVOID || e->k == VJMP, "bad expr type %d", e->k); + return; + } + bcemit_INS(fs, ins); +noins: + e->u.s.info = reg; + e->k = VNONRELOC; +} + +/* Forward declaration. */ +static BCPos bcemit_jmp(FuncState *fs); + +/* Discharge an expression to a specific register. */ +static void expr_toreg(FuncState *fs, ExpDesc *e, BCReg reg) +{ + expr_toreg_nobranch(fs, e, reg); + if (e->k == VJMP) + jmp_append(fs, &e->t, e->u.s.info); /* Add it to the true jump list. */ + if (expr_hasjump(e)) { /* Discharge expression with branches. */ + BCPos jend, jfalse = NO_JMP, jtrue = NO_JMP; + if (jmp_novalue(fs, e->t) || jmp_novalue(fs, e->f)) { + BCPos jval = (e->k == VJMP) ? NO_JMP : bcemit_jmp(fs); + jfalse = bcemit_AD(fs, BC_KPRI, reg, VKFALSE); + bcemit_AJ(fs, BC_JMP, fs->freereg, 1); + jtrue = bcemit_AD(fs, BC_KPRI, reg, VKTRUE); + jmp_tohere(fs, jval); + } + jend = fs->pc; + fs->lasttarget = jend; + jmp_patchval(fs, e->f, jend, reg, jfalse); + jmp_patchval(fs, e->t, jend, reg, jtrue); + } + e->f = e->t = NO_JMP; + e->u.s.info = reg; + e->k = VNONRELOC; +} + +/* Discharge an expression to the next free register. */ +static void expr_tonextreg(FuncState *fs, ExpDesc *e) +{ + expr_discharge(fs, e); + expr_free(fs, e); + bcreg_reserve(fs, 1); + expr_toreg(fs, e, fs->freereg - 1); +} + +/* Discharge an expression to any register. */ +static BCReg expr_toanyreg(FuncState *fs, ExpDesc *e) +{ + expr_discharge(fs, e); + if (e->k == VNONRELOC) { + if (!expr_hasjump(e)) return e->u.s.info; /* Already in a register. */ + if (e->u.s.info >= fs->nactvar) { + expr_toreg(fs, e, e->u.s.info); /* Discharge to temp. register. */ + return e->u.s.info; + } + } + expr_tonextreg(fs, e); /* Discharge to next register. */ + return e->u.s.info; +} + +/* Partially discharge expression to a value. */ +static void expr_toval(FuncState *fs, ExpDesc *e) +{ + if (expr_hasjump(e)) + expr_toanyreg(fs, e); + else + expr_discharge(fs, e); +} + +/* Emit store for LHS expression. */ +static void bcemit_store(FuncState *fs, ExpDesc *var, ExpDesc *e) +{ + BCIns ins; + if (var->k == VLOCAL) { + fs->ls->vstack[var->u.s.aux].info |= VSTACK_VAR_RW; + expr_free(fs, e); + expr_toreg(fs, e, var->u.s.info); + return; + } else if (var->k == VUPVAL) { + fs->ls->vstack[var->u.s.aux].info |= VSTACK_VAR_RW; + expr_toval(fs, e); + if (e->k <= VKTRUE) + ins = BCINS_AD(BC_USETP, var->u.s.info, const_pri(e)); + else if (e->k == VKSTR) + ins = BCINS_AD(BC_USETS, var->u.s.info, const_str(fs, e)); + else if (e->k == VKNUM) + ins = BCINS_AD(BC_USETN, var->u.s.info, const_num(fs, e)); + else + ins = BCINS_AD(BC_USETV, var->u.s.info, expr_toanyreg(fs, e)); + } else if (var->k == VGLOBAL) { + BCReg ra = expr_toanyreg(fs, e); + ins = BCINS_AD(BC_GSET, ra, const_str(fs, var)); + } else { + BCReg ra, rc; + lj_assertFS(var->k == VINDEXED, "bad expr type %d", var->k); + ra = expr_toanyreg(fs, e); + rc = var->u.s.aux; + if ((int32_t)rc < 0) { + ins = BCINS_ABC(BC_TSETS, ra, var->u.s.info, ~rc); + } else if (rc > BCMAX_C) { + ins = BCINS_ABC(BC_TSETB, ra, var->u.s.info, rc-(BCMAX_C+1)); + } else { +#ifdef LUA_USE_ASSERT + /* Free late alloced key reg to avoid assert on free of value reg. */ + /* This can only happen when called from expr_table(). */ + if (e->k == VNONRELOC && ra >= fs->nactvar && rc >= ra) + bcreg_free(fs, rc); +#endif + ins = BCINS_ABC(BC_TSETV, ra, var->u.s.info, rc); + } + } + bcemit_INS(fs, ins); + expr_free(fs, e); +} + +/* Emit method lookup expression. */ +static void bcemit_method(FuncState *fs, ExpDesc *e, ExpDesc *key) +{ + BCReg idx, func, obj = expr_toanyreg(fs, e); + expr_free(fs, e); + func = fs->freereg; + bcemit_AD(fs, BC_MOV, func+1+LJ_FR2, obj); /* Copy object to 1st argument. */ + lj_assertFS(expr_isstrk(key), "bad usage"); + idx = const_str(fs, key); + if (idx <= BCMAX_C) { + bcreg_reserve(fs, 2+LJ_FR2); + bcemit_ABC(fs, BC_TGETS, func, obj, idx); + } else { + bcreg_reserve(fs, 3+LJ_FR2); + bcemit_AD(fs, BC_KSTR, func+2+LJ_FR2, idx); + bcemit_ABC(fs, BC_TGETV, func, obj, func+2+LJ_FR2); + fs->freereg--; + } + e->u.s.info = func; + e->k = VNONRELOC; +} + +/* -- Bytecode emitter for branches --------------------------------------- */ + +/* Emit unconditional branch. */ +static BCPos bcemit_jmp(FuncState *fs) +{ + BCPos jpc = fs->jpc; + BCPos j = fs->pc - 1; + BCIns *ip = &fs->bcbase[j].ins; + fs->jpc = NO_JMP; + if ((int32_t)j >= (int32_t)fs->lasttarget && bc_op(*ip) == BC_UCLO) { + setbc_j(ip, NO_JMP); + fs->lasttarget = j+1; + } else { + j = bcemit_AJ(fs, BC_JMP, fs->freereg, NO_JMP); + } + jmp_append(fs, &j, jpc); + return j; +} + +/* Invert branch condition of bytecode instruction. */ +static void invertcond(FuncState *fs, ExpDesc *e) +{ + BCIns *ip = &fs->bcbase[e->u.s.info - 1].ins; + setbc_op(ip, bc_op(*ip)^1); +} + +/* Emit conditional branch. */ +static BCPos bcemit_branch(FuncState *fs, ExpDesc *e, int cond) +{ + BCPos pc; + if (e->k == VRELOCABLE) { + BCIns *ip = bcptr(fs, e); + if (bc_op(*ip) == BC_NOT) { + *ip = BCINS_AD(cond ? BC_ISF : BC_IST, 0, bc_d(*ip)); + return bcemit_jmp(fs); + } + } + if (e->k != VNONRELOC) { + bcreg_reserve(fs, 1); + expr_toreg_nobranch(fs, e, fs->freereg-1); + } + bcemit_AD(fs, cond ? BC_ISTC : BC_ISFC, NO_REG, e->u.s.info); + pc = bcemit_jmp(fs); + expr_free(fs, e); + return pc; +} + +/* Emit branch on true condition. */ +static void bcemit_branch_t(FuncState *fs, ExpDesc *e) +{ + BCPos pc; + expr_discharge(fs, e); + if (e->k == VKSTR || e->k == VKNUM || e->k == VKTRUE) + pc = NO_JMP; /* Never jump. */ + else if (e->k == VJMP) + invertcond(fs, e), pc = e->u.s.info; + else if (e->k == VKFALSE || e->k == VKNIL) + expr_toreg_nobranch(fs, e, NO_REG), pc = bcemit_jmp(fs); + else + pc = bcemit_branch(fs, e, 0); + jmp_append(fs, &e->f, pc); + jmp_tohere(fs, e->t); + e->t = NO_JMP; +} + +/* Emit branch on false condition. */ +static void bcemit_branch_f(FuncState *fs, ExpDesc *e) +{ + BCPos pc; + expr_discharge(fs, e); + if (e->k == VKNIL || e->k == VKFALSE) + pc = NO_JMP; /* Never jump. */ + else if (e->k == VJMP) + pc = e->u.s.info; + else if (e->k == VKSTR || e->k == VKNUM || e->k == VKTRUE) + expr_toreg_nobranch(fs, e, NO_REG), pc = bcemit_jmp(fs); + else + pc = bcemit_branch(fs, e, 1); + jmp_append(fs, &e->t, pc); + jmp_tohere(fs, e->f); + e->f = NO_JMP; +} + +/* -- Bytecode emitter for operators -------------------------------------- */ + +/* Try constant-folding of arithmetic operators. */ +static int foldarith(BinOpr opr, ExpDesc *e1, ExpDesc *e2) +{ + TValue o; + lua_Number n; + if (!expr_isnumk_nojump(e1) || !expr_isnumk_nojump(e2)) return 0; + n = lj_vm_foldarith(expr_numberV(e1), expr_numberV(e2), (int)opr-OPR_ADD); + setnumV(&o, n); + if (tvisnan(&o) || tvismzero(&o)) return 0; /* Avoid NaN and -0 as consts. */ + if (LJ_DUALNUM) { + int32_t k = lj_num2int(n); + if ((lua_Number)k == n) { + setintV(&e1->u.nval, k); + return 1; + } + } + setnumV(&e1->u.nval, n); + return 1; +} + +/* Emit arithmetic operator. */ +static void bcemit_arith(FuncState *fs, BinOpr opr, ExpDesc *e1, ExpDesc *e2) +{ + BCReg rb, rc, t; + uint32_t op; + if (foldarith(opr, e1, e2)) + return; + if (opr == OPR_POW) { + op = BC_POW; + rc = expr_toanyreg(fs, e2); + rb = expr_toanyreg(fs, e1); + } else { + op = opr-OPR_ADD+BC_ADDVV; + /* Must discharge 2nd operand first since VINDEXED might free regs. */ + expr_toval(fs, e2); + if (expr_isnumk(e2) && (rc = const_num(fs, e2)) <= BCMAX_C) + op -= BC_ADDVV-BC_ADDVN; + else + rc = expr_toanyreg(fs, e2); + /* 1st operand discharged by bcemit_binop_left, but need KNUM/KSHORT. */ + lj_assertFS(expr_isnumk(e1) || e1->k == VNONRELOC, + "bad expr type %d", e1->k); + expr_toval(fs, e1); + /* Avoid two consts to satisfy bytecode constraints. */ + if (expr_isnumk(e1) && !expr_isnumk(e2) && + (t = const_num(fs, e1)) <= BCMAX_B) { + rb = rc; rc = t; op -= BC_ADDVV-BC_ADDNV; + } else { + rb = expr_toanyreg(fs, e1); + } + } + /* Using expr_free might cause asserts if the order is wrong. */ + if (e1->k == VNONRELOC && e1->u.s.info >= fs->nactvar) fs->freereg--; + if (e2->k == VNONRELOC && e2->u.s.info >= fs->nactvar) fs->freereg--; + e1->u.s.info = bcemit_ABC(fs, op, 0, rb, rc); + e1->k = VRELOCABLE; +} + +/* Emit comparison operator. */ +static void bcemit_comp(FuncState *fs, BinOpr opr, ExpDesc *e1, ExpDesc *e2) +{ + ExpDesc *eret = e1; + BCIns ins; + expr_toval(fs, e1); + if (opr == OPR_EQ || opr == OPR_NE) { + BCOp op = opr == OPR_EQ ? BC_ISEQV : BC_ISNEV; + BCReg ra; + if (expr_isk(e1)) { e1 = e2; e2 = eret; } /* Need constant in 2nd arg. */ + ra = expr_toanyreg(fs, e1); /* First arg must be in a reg. */ + expr_toval(fs, e2); + switch (e2->k) { + case VKNIL: case VKFALSE: case VKTRUE: + ins = BCINS_AD(op+(BC_ISEQP-BC_ISEQV), ra, const_pri(e2)); + break; + case VKSTR: + ins = BCINS_AD(op+(BC_ISEQS-BC_ISEQV), ra, const_str(fs, e2)); + break; + case VKNUM: + ins = BCINS_AD(op+(BC_ISEQN-BC_ISEQV), ra, const_num(fs, e2)); + break; + default: + ins = BCINS_AD(op, ra, expr_toanyreg(fs, e2)); + break; + } + } else { + uint32_t op = opr-OPR_LT+BC_ISLT; + BCReg ra, rd; + if ((op-BC_ISLT) & 1) { /* GT -> LT, GE -> LE */ + e1 = e2; e2 = eret; /* Swap operands. */ + op = ((op-BC_ISLT)^3)+BC_ISLT; + expr_toval(fs, e1); + ra = expr_toanyreg(fs, e1); + rd = expr_toanyreg(fs, e2); + } else { + rd = expr_toanyreg(fs, e2); + ra = expr_toanyreg(fs, e1); + } + ins = BCINS_AD(op, ra, rd); + } + /* Using expr_free might cause asserts if the order is wrong. */ + if (e1->k == VNONRELOC && e1->u.s.info >= fs->nactvar) fs->freereg--; + if (e2->k == VNONRELOC && e2->u.s.info >= fs->nactvar) fs->freereg--; + bcemit_INS(fs, ins); + eret->u.s.info = bcemit_jmp(fs); + eret->k = VJMP; +} + +/* Fixup left side of binary operator. */ +static void bcemit_binop_left(FuncState *fs, BinOpr op, ExpDesc *e) +{ + if (op == OPR_AND) { + bcemit_branch_t(fs, e); + } else if (op == OPR_OR) { + bcemit_branch_f(fs, e); + } else if (op == OPR_CONCAT) { + expr_tonextreg(fs, e); + } else if (op == OPR_EQ || op == OPR_NE) { + if (!expr_isk_nojump(e)) expr_toanyreg(fs, e); + } else { + if (!expr_isnumk_nojump(e)) expr_toanyreg(fs, e); + } +} + +/* Emit binary operator. */ +static void bcemit_binop(FuncState *fs, BinOpr op, ExpDesc *e1, ExpDesc *e2) +{ + if (op <= OPR_POW) { + bcemit_arith(fs, op, e1, e2); + } else if (op == OPR_AND) { + lj_assertFS(e1->t == NO_JMP, "jump list not closed"); + expr_discharge(fs, e2); + jmp_append(fs, &e2->f, e1->f); + *e1 = *e2; + } else if (op == OPR_OR) { + lj_assertFS(e1->f == NO_JMP, "jump list not closed"); + expr_discharge(fs, e2); + jmp_append(fs, &e2->t, e1->t); + *e1 = *e2; + } else if (op == OPR_CONCAT) { + expr_toval(fs, e2); + if (e2->k == VRELOCABLE && bc_op(*bcptr(fs, e2)) == BC_CAT) { + lj_assertFS(e1->u.s.info == bc_b(*bcptr(fs, e2))-1, + "bad CAT stack layout"); + expr_free(fs, e1); + setbc_b(bcptr(fs, e2), e1->u.s.info); + e1->u.s.info = e2->u.s.info; + } else { + expr_tonextreg(fs, e2); + expr_free(fs, e2); + expr_free(fs, e1); + e1->u.s.info = bcemit_ABC(fs, BC_CAT, 0, e1->u.s.info, e2->u.s.info); + } + e1->k = VRELOCABLE; + } else { + lj_assertFS(op == OPR_NE || op == OPR_EQ || + op == OPR_LT || op == OPR_GE || op == OPR_LE || op == OPR_GT, + "bad binop %d", op); + bcemit_comp(fs, op, e1, e2); + } +} + +/* Emit unary operator. */ +static void bcemit_unop(FuncState *fs, BCOp op, ExpDesc *e) +{ + if (op == BC_NOT) { + /* Swap true and false lists. */ + { BCPos temp = e->f; e->f = e->t; e->t = temp; } + jmp_dropval(fs, e->f); + jmp_dropval(fs, e->t); + expr_discharge(fs, e); + if (e->k == VKNIL || e->k == VKFALSE) { + e->k = VKTRUE; + return; + } else if (expr_isk(e) || (LJ_HASFFI && e->k == VKCDATA)) { + e->k = VKFALSE; + return; + } else if (e->k == VJMP) { + invertcond(fs, e); + return; + } else if (e->k == VRELOCABLE) { + bcreg_reserve(fs, 1); + setbc_a(bcptr(fs, e), fs->freereg-1); + e->u.s.info = fs->freereg-1; + e->k = VNONRELOC; + } else { + lj_assertFS(e->k == VNONRELOC, "bad expr type %d", e->k); + } + } else { + lj_assertFS(op == BC_UNM || op == BC_LEN, "bad unop %d", op); + if (op == BC_UNM && !expr_hasjump(e)) { /* Constant-fold negations. */ +#if LJ_HASFFI + if (e->k == VKCDATA) { /* Fold in-place since cdata is not interned. */ + GCcdata *cd = cdataV(&e->u.nval); + int64_t *p = (int64_t *)cdataptr(cd); + if (cd->ctypeid == CTID_COMPLEX_DOUBLE) + p[1] ^= (int64_t)U64x(80000000,00000000); + else + *p = -*p; + return; + } else +#endif + if (expr_isnumk(e) && !expr_numiszero(e)) { /* Avoid folding to -0. */ + TValue *o = expr_numtv(e); + if (tvisint(o)) { + int32_t k = intV(o); + if (k == -k) + setnumV(o, -(lua_Number)k); + else + setintV(o, -k); + return; + } else { + o->u64 ^= U64x(80000000,00000000); + return; + } + } + } + expr_toanyreg(fs, e); + } + expr_free(fs, e); + e->u.s.info = bcemit_AD(fs, op, 0, e->u.s.info); + e->k = VRELOCABLE; +} + +/* -- Lexer support ------------------------------------------------------- */ + +/* Check and consume optional token. */ +static int lex_opt(LexState *ls, LexToken tok) +{ + if (ls->tok == tok) { + lj_lex_next(ls); + return 1; + } + return 0; +} + +/* Check and consume token. */ +static void lex_check(LexState *ls, LexToken tok) +{ + if (ls->tok != tok) + err_token(ls, tok); + lj_lex_next(ls); +} + +/* Check for matching token. */ +static void lex_match(LexState *ls, LexToken what, LexToken who, BCLine line) +{ + if (!lex_opt(ls, what)) { + if (line == ls->linenumber) { + err_token(ls, what); + } else { + const char *swhat = lj_lex_token2str(ls, what); + const char *swho = lj_lex_token2str(ls, who); + lj_lex_error(ls, ls->tok, LJ_ERR_XMATCH, swhat, swho, line); + } + } +} + +/* Check for string token. */ +static GCstr *lex_str(LexState *ls) +{ + GCstr *s; + if (ls->tok != TK_name && (LJ_52 || ls->tok != TK_goto)) + err_token(ls, TK_name); + s = strV(&ls->tokval); + lj_lex_next(ls); + return s; +} + +/* -- Variable handling --------------------------------------------------- */ + +#define var_get(ls, fs, i) ((ls)->vstack[(fs)->varmap[(i)]]) + +/* Define a new local variable. */ +static void var_new(LexState *ls, BCReg n, GCstr *name) +{ + FuncState *fs = ls->fs; + MSize vtop = ls->vtop; + checklimit(fs, fs->nactvar+n, LJ_MAX_LOCVAR, "local variables"); + if (LJ_UNLIKELY(vtop >= ls->sizevstack)) { + if (ls->sizevstack >= LJ_MAX_VSTACK) + lj_lex_error(ls, 0, LJ_ERR_XLIMC, LJ_MAX_VSTACK); + lj_mem_growvec(ls->L, ls->vstack, ls->sizevstack, LJ_MAX_VSTACK, VarInfo); + } + lj_assertFS((uintptr_t)name < VARNAME__MAX || + lj_tab_getstr(fs->kt, name) != NULL, + "unanchored variable name"); + /* NOBARRIER: name is anchored in fs->kt and ls->vstack is not a GCobj. */ + setgcref(ls->vstack[vtop].name, obj2gco(name)); + fs->varmap[fs->nactvar+n] = (uint16_t)vtop; + ls->vtop = vtop+1; +} + +#define var_new_lit(ls, n, v) \ + var_new(ls, (n), lj_parse_keepstr(ls, "" v, sizeof(v)-1)) + +#define var_new_fixed(ls, n, vn) \ + var_new(ls, (n), (GCstr *)(uintptr_t)(vn)) + +/* Add local variables. */ +static void var_add(LexState *ls, BCReg nvars) +{ + FuncState *fs = ls->fs; + BCReg nactvar = fs->nactvar; + while (nvars--) { + VarInfo *v = &var_get(ls, fs, nactvar); + v->startpc = fs->pc; + v->slot = nactvar++; + v->info = 0; + } + fs->nactvar = nactvar; +} + +/* Remove local variables. */ +static void var_remove(LexState *ls, BCReg tolevel) +{ + FuncState *fs = ls->fs; + while (fs->nactvar > tolevel) + var_get(ls, fs, --fs->nactvar).endpc = fs->pc; +} + +/* Lookup local variable name. */ +static BCReg var_lookup_local(FuncState *fs, GCstr *n) +{ + int i; + for (i = fs->nactvar-1; i >= 0; i--) { + if (n == strref(var_get(fs->ls, fs, i).name)) + return (BCReg)i; + } + return (BCReg)-1; /* Not found. */ +} + +/* Lookup or add upvalue index. */ +static MSize var_lookup_uv(FuncState *fs, MSize vidx, ExpDesc *e) +{ + MSize i, n = fs->nuv; + for (i = 0; i < n; i++) + if (fs->uvmap[i] == vidx) + return i; /* Already exists. */ + /* Otherwise create a new one. */ + checklimit(fs, fs->nuv, LJ_MAX_UPVAL, "upvalues"); + lj_assertFS(e->k == VLOCAL || e->k == VUPVAL, "bad expr type %d", e->k); + fs->uvmap[n] = (uint16_t)vidx; + fs->uvtmp[n] = (uint16_t)(e->k == VLOCAL ? vidx : LJ_MAX_VSTACK+e->u.s.info); + fs->nuv = n+1; + return n; +} + +/* Forward declaration. */ +static void fscope_uvmark(FuncState *fs, BCReg level); + +/* Recursively lookup variables in enclosing functions. */ +static MSize var_lookup_(FuncState *fs, GCstr *name, ExpDesc *e, int first) +{ + if (fs) { + BCReg reg = var_lookup_local(fs, name); + if ((int32_t)reg >= 0) { /* Local in this function? */ + expr_init(e, VLOCAL, reg); + if (!first) + fscope_uvmark(fs, reg); /* Scope now has an upvalue. */ + return (MSize)(e->u.s.aux = (uint32_t)fs->varmap[reg]); + } else { + MSize vidx = var_lookup_(fs->prev, name, e, 0); /* Var in outer func? */ + if ((int32_t)vidx >= 0) { /* Yes, make it an upvalue here. */ + e->u.s.info = (uint8_t)var_lookup_uv(fs, vidx, e); + e->k = VUPVAL; + return vidx; + } + } + } else { /* Not found in any function, must be a global. */ + expr_init(e, VGLOBAL, 0); + e->u.sval = name; + } + return (MSize)-1; /* Global. */ +} + +/* Lookup variable name. */ +#define var_lookup(ls, e) \ + var_lookup_((ls)->fs, lex_str(ls), (e), 1) + +/* -- Goto an label handling ---------------------------------------------- */ + +/* Add a new goto or label. */ +static MSize gola_new(LexState *ls, GCstr *name, uint8_t info, BCPos pc) +{ + FuncState *fs = ls->fs; + MSize vtop = ls->vtop; + if (LJ_UNLIKELY(vtop >= ls->sizevstack)) { + if (ls->sizevstack >= LJ_MAX_VSTACK) + lj_lex_error(ls, 0, LJ_ERR_XLIMC, LJ_MAX_VSTACK); + lj_mem_growvec(ls->L, ls->vstack, ls->sizevstack, LJ_MAX_VSTACK, VarInfo); + } + lj_assertFS(name == NAME_BREAK || lj_tab_getstr(fs->kt, name) != NULL, + "unanchored label name"); + /* NOBARRIER: name is anchored in fs->kt and ls->vstack is not a GCobj. */ + setgcref(ls->vstack[vtop].name, obj2gco(name)); + ls->vstack[vtop].startpc = pc; + ls->vstack[vtop].slot = (uint8_t)fs->nactvar; + ls->vstack[vtop].info = info; + ls->vtop = vtop+1; + return vtop; +} + +#define gola_isgoto(v) ((v)->info & VSTACK_GOTO) +#define gola_islabel(v) ((v)->info & VSTACK_LABEL) +#define gola_isgotolabel(v) ((v)->info & (VSTACK_GOTO|VSTACK_LABEL)) + +/* Patch goto to jump to label. */ +static void gola_patch(LexState *ls, VarInfo *vg, VarInfo *vl) +{ + FuncState *fs = ls->fs; + BCPos pc = vg->startpc; + setgcrefnull(vg->name); /* Invalidate pending goto. */ + setbc_a(&fs->bcbase[pc].ins, vl->slot); + jmp_patch(fs, pc, vl->startpc); +} + +/* Patch goto to close upvalues. */ +static void gola_close(LexState *ls, VarInfo *vg) +{ + FuncState *fs = ls->fs; + BCPos pc = vg->startpc; + BCIns *ip = &fs->bcbase[pc].ins; + lj_assertFS(gola_isgoto(vg), "expected goto"); + lj_assertFS(bc_op(*ip) == BC_JMP || bc_op(*ip) == BC_UCLO, + "bad bytecode op %d", bc_op(*ip)); + setbc_a(ip, vg->slot); + if (bc_op(*ip) == BC_JMP) { + BCPos next = jmp_next(fs, pc); + if (next != NO_JMP) jmp_patch(fs, next, pc); /* Jump to UCLO. */ + setbc_op(ip, BC_UCLO); /* Turn into UCLO. */ + setbc_j(ip, NO_JMP); + } +} + +/* Resolve pending forward gotos for label. */ +static void gola_resolve(LexState *ls, FuncScope *bl, MSize idx) +{ + VarInfo *vg = ls->vstack + bl->vstart; + VarInfo *vl = ls->vstack + idx; + for (; vg < vl; vg++) + if (gcrefeq(vg->name, vl->name) && gola_isgoto(vg)) { + if (vg->slot < vl->slot) { + GCstr *name = strref(var_get(ls, ls->fs, vg->slot).name); + lj_assertLS((uintptr_t)name >= VARNAME__MAX, "expected goto name"); + ls->linenumber = ls->fs->bcbase[vg->startpc].line; + lj_assertLS(strref(vg->name) != NAME_BREAK, "unexpected break"); + lj_lex_error(ls, 0, LJ_ERR_XGSCOPE, + strdata(strref(vg->name)), strdata(name)); + } + gola_patch(ls, vg, vl); + } +} + +/* Fixup remaining gotos and labels for scope. */ +static void gola_fixup(LexState *ls, FuncScope *bl) +{ + VarInfo *v = ls->vstack + bl->vstart; + VarInfo *ve = ls->vstack + ls->vtop; + for (; v < ve; v++) { + GCstr *name = strref(v->name); + if (name != NULL) { /* Only consider remaining valid gotos/labels. */ + if (gola_islabel(v)) { + VarInfo *vg; + setgcrefnull(v->name); /* Invalidate label that goes out of scope. */ + for (vg = v+1; vg < ve; vg++) /* Resolve pending backward gotos. */ + if (strref(vg->name) == name && gola_isgoto(vg)) { + if ((bl->flags&FSCOPE_UPVAL) && vg->slot > v->slot) + gola_close(ls, vg); + gola_patch(ls, vg, v); + } + } else if (gola_isgoto(v)) { + if (bl->prev) { /* Propagate goto or break to outer scope. */ + bl->prev->flags |= name == NAME_BREAK ? FSCOPE_BREAK : FSCOPE_GOLA; + v->slot = bl->nactvar; + if ((bl->flags & FSCOPE_UPVAL)) + gola_close(ls, v); + } else { /* No outer scope: undefined goto label or no loop. */ + ls->linenumber = ls->fs->bcbase[v->startpc].line; + if (name == NAME_BREAK) + lj_lex_error(ls, 0, LJ_ERR_XBREAK); + else + lj_lex_error(ls, 0, LJ_ERR_XLUNDEF, strdata(name)); + } + } + } + } +} + +/* Find existing label. */ +static VarInfo *gola_findlabel(LexState *ls, GCstr *name) +{ + VarInfo *v = ls->vstack + ls->fs->bl->vstart; + VarInfo *ve = ls->vstack + ls->vtop; + for (; v < ve; v++) + if (strref(v->name) == name && gola_islabel(v)) + return v; + return NULL; +} + +/* -- Scope handling ------------------------------------------------------ */ + +/* Begin a scope. */ +static void fscope_begin(FuncState *fs, FuncScope *bl, int flags) +{ + bl->nactvar = (uint8_t)fs->nactvar; + bl->flags = flags; + bl->vstart = fs->ls->vtop; + bl->prev = fs->bl; + fs->bl = bl; + lj_assertFS(fs->freereg == fs->nactvar, "bad regalloc"); +} + +/* End a scope. */ +static void fscope_end(FuncState *fs) +{ + FuncScope *bl = fs->bl; + LexState *ls = fs->ls; + fs->bl = bl->prev; + var_remove(ls, bl->nactvar); + fs->freereg = fs->nactvar; + lj_assertFS(bl->nactvar == fs->nactvar, "bad regalloc"); + if ((bl->flags & (FSCOPE_UPVAL|FSCOPE_NOCLOSE)) == FSCOPE_UPVAL) + bcemit_AJ(fs, BC_UCLO, bl->nactvar, 0); + if ((bl->flags & FSCOPE_BREAK)) { + if ((bl->flags & FSCOPE_LOOP)) { + MSize idx = gola_new(ls, NAME_BREAK, VSTACK_LABEL, fs->pc); + ls->vtop = idx; /* Drop break label immediately. */ + gola_resolve(ls, bl, idx); + } else { /* Need the fixup step to propagate the breaks. */ + gola_fixup(ls, bl); + return; + } + } + if ((bl->flags & FSCOPE_GOLA)) { + gola_fixup(ls, bl); + } +} + +/* Mark scope as having an upvalue. */ +static void fscope_uvmark(FuncState *fs, BCReg level) +{ + FuncScope *bl; + for (bl = fs->bl; bl && bl->nactvar > level; bl = bl->prev) + ; + if (bl) + bl->flags |= FSCOPE_UPVAL; +} + +/* -- Function state management ------------------------------------------- */ + +/* Fixup bytecode for prototype. */ +static void fs_fixup_bc(FuncState *fs, GCproto *pt, BCIns *bc, MSize n) +{ + BCInsLine *base = fs->bcbase; + MSize i; + pt->sizebc = n; + bc[0] = BCINS_AD((fs->flags & PROTO_VARARG) ? BC_FUNCV : BC_FUNCF, + fs->framesize, 0); + for (i = 1; i < n; i++) + bc[i] = base[i].ins; +} + +/* Fixup upvalues for child prototype, step #2. */ +static void fs_fixup_uv2(FuncState *fs, GCproto *pt) +{ + VarInfo *vstack = fs->ls->vstack; + uint16_t *uv = proto_uv(pt); + MSize i, n = pt->sizeuv; + for (i = 0; i < n; i++) { + VarIndex vidx = uv[i]; + if (vidx >= LJ_MAX_VSTACK) + uv[i] = vidx - LJ_MAX_VSTACK; + else if ((vstack[vidx].info & VSTACK_VAR_RW)) + uv[i] = vstack[vidx].slot | PROTO_UV_LOCAL; + else + uv[i] = vstack[vidx].slot | PROTO_UV_LOCAL | PROTO_UV_IMMUTABLE; + } +} + +/* Fixup constants for prototype. */ +static void fs_fixup_k(FuncState *fs, GCproto *pt, void *kptr) +{ + GCtab *kt; + TValue *array; + Node *node; + MSize i, hmask; + checklimitgt(fs, fs->nkn, BCMAX_D+1, "constants"); + checklimitgt(fs, fs->nkgc, BCMAX_D+1, "constants"); + setmref(pt->k, kptr); + pt->sizekn = fs->nkn; + pt->sizekgc = fs->nkgc; + kt = fs->kt; + array = tvref(kt->array); + for (i = 0; i < kt->asize; i++) + if (tvhaskslot(&array[i])) { + TValue *tv = &((TValue *)kptr)[tvkslot(&array[i])]; + if (LJ_DUALNUM) + setintV(tv, (int32_t)i); + else + setnumV(tv, (lua_Number)i); + } + node = noderef(kt->node); + hmask = kt->hmask; + for (i = 0; i <= hmask; i++) { + Node *n = &node[i]; + if (tvhaskslot(&n->val)) { + ptrdiff_t kidx = (ptrdiff_t)tvkslot(&n->val); + lj_assertFS(!tvisint(&n->key), "unexpected integer key"); + if (tvisnum(&n->key)) { + TValue *tv = &((TValue *)kptr)[kidx]; + if (LJ_DUALNUM) { + lua_Number nn = numV(&n->key); + int32_t k = lj_num2int(nn); + lj_assertFS(!tvismzero(&n->key), "unexpected -0 key"); + if ((lua_Number)k == nn) + setintV(tv, k); + else + *tv = n->key; + } else { + *tv = n->key; + } + } else { + GCobj *o = gcV(&n->key); + setgcref(((GCRef *)kptr)[~kidx], o); + lj_gc_objbarrier(fs->L, pt, o); + if (tvisproto(&n->key)) + fs_fixup_uv2(fs, gco2pt(o)); + } + } + } +} + +/* Fixup upvalues for prototype, step #1. */ +static void fs_fixup_uv1(FuncState *fs, GCproto *pt, uint16_t *uv) +{ + setmref(pt->uv, uv); + pt->sizeuv = fs->nuv; + memcpy(uv, fs->uvtmp, fs->nuv*sizeof(VarIndex)); +} + +#ifndef LUAJIT_DISABLE_DEBUGINFO +/* Prepare lineinfo for prototype. */ +static size_t fs_prep_line(FuncState *fs, BCLine numline) +{ + return (fs->pc-1) << (numline < 256 ? 0 : numline < 65536 ? 1 : 2); +} + +/* Fixup lineinfo for prototype. */ +static void fs_fixup_line(FuncState *fs, GCproto *pt, + void *lineinfo, BCLine numline) +{ + BCInsLine *base = fs->bcbase + 1; + BCLine first = fs->linedefined; + MSize i = 0, n = fs->pc-1; + pt->firstline = fs->linedefined; + pt->numline = numline; + setmref(pt->lineinfo, lineinfo); + if (LJ_LIKELY(numline < 256)) { + uint8_t *li = (uint8_t *)lineinfo; + do { + BCLine delta = base[i].line - first; + lj_assertFS(delta >= 0 && delta < 256, "bad line delta"); + li[i] = (uint8_t)delta; + } while (++i < n); + } else if (LJ_LIKELY(numline < 65536)) { + uint16_t *li = (uint16_t *)lineinfo; + do { + BCLine delta = base[i].line - first; + lj_assertFS(delta >= 0 && delta < 65536, "bad line delta"); + li[i] = (uint16_t)delta; + } while (++i < n); + } else { + uint32_t *li = (uint32_t *)lineinfo; + do { + BCLine delta = base[i].line - first; + lj_assertFS(delta >= 0, "bad line delta"); + li[i] = (uint32_t)delta; + } while (++i < n); + } +} + +/* Prepare variable info for prototype. */ +static size_t fs_prep_var(LexState *ls, FuncState *fs, size_t *ofsvar) +{ + VarInfo *vs =ls->vstack, *ve; + MSize i, n; + BCPos lastpc; + lj_buf_reset(&ls->sb); /* Copy to temp. string buffer. */ + /* Store upvalue names. */ + for (i = 0, n = fs->nuv; i < n; i++) { + GCstr *s = strref(vs[fs->uvmap[i]].name); + MSize len = s->len+1; + char *p = lj_buf_more(&ls->sb, len); + p = lj_buf_wmem(p, strdata(s), len); + ls->sb.w = p; + } + *ofsvar = sbuflen(&ls->sb); + lastpc = 0; + /* Store local variable names and compressed ranges. */ + for (ve = vs + ls->vtop, vs += fs->vbase; vs < ve; vs++) { + if (!gola_isgotolabel(vs)) { + GCstr *s = strref(vs->name); + BCPos startpc; + char *p; + if ((uintptr_t)s < VARNAME__MAX) { + p = lj_buf_more(&ls->sb, 1 + 2*5); + *p++ = (char)(uintptr_t)s; + } else { + MSize len = s->len+1; + p = lj_buf_more(&ls->sb, len + 2*5); + p = lj_buf_wmem(p, strdata(s), len); + } + startpc = vs->startpc; + p = lj_strfmt_wuleb128(p, startpc-lastpc); + p = lj_strfmt_wuleb128(p, vs->endpc-startpc); + ls->sb.w = p; + lastpc = startpc; + } + } + lj_buf_putb(&ls->sb, '\0'); /* Terminator for varinfo. */ + return sbuflen(&ls->sb); +} + +/* Fixup variable info for prototype. */ +static void fs_fixup_var(LexState *ls, GCproto *pt, uint8_t *p, size_t ofsvar) +{ + setmref(pt->uvinfo, p); + setmref(pt->varinfo, (char *)p + ofsvar); + memcpy(p, ls->sb.b, sbuflen(&ls->sb)); /* Copy from temp. buffer. */ +} +#else + +/* Initialize with empty debug info, if disabled. */ +#define fs_prep_line(fs, numline) (UNUSED(numline), 0) +#define fs_fixup_line(fs, pt, li, numline) \ + pt->firstline = pt->numline = 0, setmref((pt)->lineinfo, NULL) +#define fs_prep_var(ls, fs, ofsvar) (UNUSED(ofsvar), 0) +#define fs_fixup_var(ls, pt, p, ofsvar) \ + setmref((pt)->uvinfo, NULL), setmref((pt)->varinfo, NULL) + +#endif + +/* Check if bytecode op returns. */ +static int bcopisret(BCOp op) +{ + switch (op) { + case BC_CALLMT: case BC_CALLT: + case BC_RETM: case BC_RET: case BC_RET0: case BC_RET1: + return 1; + default: + return 0; + } +} + +/* Fixup return instruction for prototype. */ +static void fs_fixup_ret(FuncState *fs) +{ + BCPos lastpc = fs->pc; + if (lastpc <= fs->lasttarget || !bcopisret(bc_op(fs->bcbase[lastpc-1].ins))) { + if ((fs->bl->flags & FSCOPE_UPVAL)) + bcemit_AJ(fs, BC_UCLO, 0, 0); + bcemit_AD(fs, BC_RET0, 0, 1); /* Need final return. */ + } + fs->bl->flags |= FSCOPE_NOCLOSE; /* Handled above. */ + fscope_end(fs); + lj_assertFS(fs->bl == NULL, "bad scope nesting"); + /* May need to fixup returns encoded before first function was created. */ + if (fs->flags & PROTO_FIXUP_RETURN) { + BCPos pc; + for (pc = 1; pc < lastpc; pc++) { + BCIns ins = fs->bcbase[pc].ins; + BCPos offset; + switch (bc_op(ins)) { + case BC_CALLMT: case BC_CALLT: + case BC_RETM: case BC_RET: case BC_RET0: case BC_RET1: + offset = bcemit_INS(fs, ins); /* Copy original instruction. */ + fs->bcbase[offset].line = fs->bcbase[pc].line; + offset = offset-(pc+1)+BCBIAS_J; + if (offset > BCMAX_D) + err_syntax(fs->ls, LJ_ERR_XFIXUP); + /* Replace with UCLO plus branch. */ + fs->bcbase[pc].ins = BCINS_AD(BC_UCLO, 0, offset); + break; + case BC_FNEW: + return; /* We're done. */ + default: + break; + } + } + } +} + +/* Finish a FuncState and return the new prototype. */ +static GCproto *fs_finish(LexState *ls, BCLine line) +{ + lua_State *L = ls->L; + FuncState *fs = ls->fs; + BCLine numline = line - fs->linedefined; + size_t sizept, ofsk, ofsuv, ofsli, ofsdbg, ofsvar; + GCproto *pt; + + /* Apply final fixups. */ + fs_fixup_ret(fs); + + /* Calculate total size of prototype including all colocated arrays. */ + sizept = sizeof(GCproto) + fs->pc*sizeof(BCIns) + fs->nkgc*sizeof(GCRef); + sizept = (sizept + sizeof(TValue)-1) & ~(sizeof(TValue)-1); + ofsk = sizept; sizept += fs->nkn*sizeof(TValue); + ofsuv = sizept; sizept += ((fs->nuv+1)&~1)*2; + ofsli = sizept; sizept += fs_prep_line(fs, numline); + ofsdbg = sizept; sizept += fs_prep_var(ls, fs, &ofsvar); + + /* Allocate prototype and initialize its fields. */ + pt = (GCproto *)lj_mem_newgco(L, (MSize)sizept); + pt->gct = ~LJ_TPROTO; + pt->sizept = (MSize)sizept; + pt->trace = 0; + pt->flags = (uint8_t)(fs->flags & ~(PROTO_HAS_RETURN|PROTO_FIXUP_RETURN)); + pt->numparams = fs->numparams; + pt->framesize = fs->framesize; + setgcref(pt->chunkname, obj2gco(ls->chunkname)); + + /* Close potentially uninitialized gap between bc and kgc. */ + *(uint32_t *)((char *)pt + ofsk - sizeof(GCRef)*(fs->nkgc+1)) = 0; + fs_fixup_bc(fs, pt, (BCIns *)((char *)pt + sizeof(GCproto)), fs->pc); + fs_fixup_k(fs, pt, (void *)((char *)pt + ofsk)); + fs_fixup_uv1(fs, pt, (uint16_t *)((char *)pt + ofsuv)); + fs_fixup_line(fs, pt, (void *)((char *)pt + ofsli), numline); + fs_fixup_var(ls, pt, (uint8_t *)((char *)pt + ofsdbg), ofsvar); + + lj_vmevent_send(L, BC, + setprotoV(L, L->top++, pt); + ); + + L->top--; /* Pop table of constants. */ + ls->vtop = fs->vbase; /* Reset variable stack. */ + ls->fs = fs->prev; + lj_assertL(ls->fs != NULL || ls->tok == TK_eof, "bad parser state"); + return pt; +} + +/* Initialize a new FuncState. */ +static void fs_init(LexState *ls, FuncState *fs) +{ + lua_State *L = ls->L; + fs->prev = ls->fs; ls->fs = fs; /* Append to list. */ + fs->ls = ls; + fs->vbase = ls->vtop; + fs->L = L; + fs->pc = 0; + fs->lasttarget = 0; + fs->jpc = NO_JMP; + fs->freereg = 0; + fs->nkgc = 0; + fs->nkn = 0; + fs->nactvar = 0; + fs->nuv = 0; + fs->bl = NULL; + fs->flags = 0; + fs->framesize = 1; /* Minimum frame size. */ + fs->kt = lj_tab_new(L, 0, 0); + /* Anchor table of constants in stack to avoid being collected. */ + settabV(L, L->top, fs->kt); + incr_top(L); +} + +/* -- Expressions --------------------------------------------------------- */ + +/* Forward declaration. */ +static void expr(LexState *ls, ExpDesc *v); + +/* Return string expression. */ +static void expr_str(LexState *ls, ExpDesc *e) +{ + expr_init(e, VKSTR, 0); + e->u.sval = lex_str(ls); +} + +/* Return index expression. */ +static void expr_index(FuncState *fs, ExpDesc *t, ExpDesc *e) +{ + /* Already called: expr_toval(fs, e). */ + t->k = VINDEXED; + if (expr_isnumk(e)) { +#if LJ_DUALNUM + if (tvisint(expr_numtv(e))) { + int32_t k = intV(expr_numtv(e)); + if (checku8(k)) { + t->u.s.aux = BCMAX_C+1+(uint32_t)k; /* 256..511: const byte key */ + return; + } + } +#else + lua_Number n = expr_numberV(e); + int32_t k = lj_num2int(n); + if (checku8(k) && n == (lua_Number)k) { + t->u.s.aux = BCMAX_C+1+(uint32_t)k; /* 256..511: const byte key */ + return; + } +#endif + } else if (expr_isstrk(e)) { + BCReg idx = const_str(fs, e); + if (idx <= BCMAX_C) { + t->u.s.aux = ~idx; /* -256..-1: const string key */ + return; + } + } + t->u.s.aux = expr_toanyreg(fs, e); /* 0..255: register */ +} + +/* Parse index expression with named field. */ +static void expr_field(LexState *ls, ExpDesc *v) +{ + FuncState *fs = ls->fs; + ExpDesc key; + expr_toanyreg(fs, v); + lj_lex_next(ls); /* Skip dot or colon. */ + expr_str(ls, &key); + expr_index(fs, v, &key); +} + +/* Parse index expression with brackets. */ +static void expr_bracket(LexState *ls, ExpDesc *v) +{ + lj_lex_next(ls); /* Skip '['. */ + expr(ls, v); + expr_toval(ls->fs, v); + lex_check(ls, ']'); +} + +/* Get value of constant expression. */ +static void expr_kvalue(FuncState *fs, TValue *v, ExpDesc *e) +{ + UNUSED(fs); + if (e->k <= VKTRUE) { + setpriV(v, ~(uint32_t)e->k); + } else if (e->k == VKSTR) { + setgcVraw(v, obj2gco(e->u.sval), LJ_TSTR); + } else { + lj_assertFS(tvisnumber(expr_numtv(e)), "bad number constant"); + *v = *expr_numtv(e); + } +} + +/* Parse table constructor expression. */ +static void expr_table(LexState *ls, ExpDesc *e) +{ + FuncState *fs = ls->fs; + BCLine line = ls->linenumber; + GCtab *t = NULL; + int vcall = 0, needarr = 0, fixt = 0; + uint32_t narr = 1; /* First array index. */ + uint32_t nhash = 0; /* Number of hash entries. */ + BCReg freg = fs->freereg; + BCPos pc = bcemit_AD(fs, BC_TNEW, freg, 0); + expr_init(e, VNONRELOC, freg); + bcreg_reserve(fs, 1); + freg++; + lex_check(ls, '{'); + while (ls->tok != '}') { + ExpDesc key, val; + vcall = 0; + if (ls->tok == '[') { + expr_bracket(ls, &key); /* Already calls expr_toval. */ + if (!expr_isk(&key)) expr_index(fs, e, &key); + if (expr_isnumk(&key) && expr_numiszero(&key)) needarr = 1; else nhash++; + lex_check(ls, '='); + } else if ((ls->tok == TK_name || (!LJ_52 && ls->tok == TK_goto)) && + lj_lex_lookahead(ls) == '=') { + expr_str(ls, &key); + lex_check(ls, '='); + nhash++; + } else { + expr_init(&key, VKNUM, 0); + setintV(&key.u.nval, (int)narr); + narr++; + needarr = vcall = 1; + } + expr(ls, &val); + if (expr_isk(&key) && key.k != VKNIL && + (key.k == VKSTR || expr_isk_nojump(&val))) { + TValue k, *v; + if (!t) { /* Create template table on demand. */ + BCReg kidx; + t = lj_tab_new(fs->L, needarr ? narr : 0, hsize2hbits(nhash)); + kidx = const_gc(fs, obj2gco(t), LJ_TTAB); + fs->bcbase[pc].ins = BCINS_AD(BC_TDUP, freg-1, kidx); + } + vcall = 0; + expr_kvalue(fs, &k, &key); + v = lj_tab_set(fs->L, t, &k); + lj_gc_anybarriert(fs->L, t); + if (expr_isk_nojump(&val)) { /* Add const key/value to template table. */ + expr_kvalue(fs, v, &val); + } else { /* Otherwise create dummy string key (avoids lj_tab_newkey). */ + settabV(fs->L, v, t); /* Preserve key with table itself as value. */ + fixt = 1; /* Fix this later, after all resizes. */ + goto nonconst; + } + } else { + nonconst: + if (val.k != VCALL) { expr_toanyreg(fs, &val); vcall = 0; } + if (expr_isk(&key)) expr_index(fs, e, &key); + bcemit_store(fs, e, &val); + } + fs->freereg = freg; + if (!lex_opt(ls, ',') && !lex_opt(ls, ';')) break; + } + lex_match(ls, '}', '{', line); + if (vcall) { + BCInsLine *ilp = &fs->bcbase[fs->pc-1]; + ExpDesc en; + lj_assertFS(bc_a(ilp->ins) == freg && + bc_op(ilp->ins) == (narr > 256 ? BC_TSETV : BC_TSETB), + "bad CALL code generation"); + expr_init(&en, VKNUM, 0); + en.u.nval.u32.lo = narr-1; + en.u.nval.u32.hi = 0x43300000; /* Biased integer to avoid denormals. */ + if (narr > 256) { fs->pc--; ilp--; } + ilp->ins = BCINS_AD(BC_TSETM, freg, const_num(fs, &en)); + setbc_b(&ilp[-1].ins, 0); + } + if (pc == fs->pc-1) { /* Make expr relocable if possible. */ + e->u.s.info = pc; + fs->freereg--; + e->k = VRELOCABLE; + } else { + e->k = VNONRELOC; /* May have been changed by expr_index. */ + } + if (!t) { /* Construct TNEW RD: hhhhhaaaaaaaaaaa. */ + BCIns *ip = &fs->bcbase[pc].ins; + if (!needarr) narr = 0; + else if (narr < 3) narr = 3; + else if (narr > 0x7ff) narr = 0x7ff; + setbc_d(ip, narr|(hsize2hbits(nhash)<<11)); + } else { + if (needarr && t->asize < narr) + lj_tab_reasize(fs->L, t, narr-1); + if (fixt) { /* Fix value for dummy keys in template table. */ + Node *node = noderef(t->node); + uint32_t i, hmask = t->hmask; + for (i = 0; i <= hmask; i++) { + Node *n = &node[i]; + if (tvistab(&n->val)) { + lj_assertFS(tabV(&n->val) == t, "bad dummy key in template table"); + setnilV(&n->val); /* Turn value into nil. */ + } + } + } + lj_gc_check(fs->L); + } +} + +/* Parse function parameters. */ +static BCReg parse_params(LexState *ls, int needself) +{ + FuncState *fs = ls->fs; + BCReg nparams = 0; + lex_check(ls, '('); + if (needself) + var_new_lit(ls, nparams++, "self"); + if (ls->tok != ')') { + do { + if (ls->tok == TK_name || (!LJ_52 && ls->tok == TK_goto)) { + var_new(ls, nparams++, lex_str(ls)); + } else if (ls->tok == TK_dots) { + lj_lex_next(ls); + fs->flags |= PROTO_VARARG; + break; + } else { + err_syntax(ls, LJ_ERR_XPARAM); + } + } while (lex_opt(ls, ',')); + } + var_add(ls, nparams); + lj_assertFS(fs->nactvar == nparams, "bad regalloc"); + bcreg_reserve(fs, nparams); + lex_check(ls, ')'); + return nparams; +} + +/* Forward declaration. */ +static void parse_chunk(LexState *ls); + +/* Parse body of a function. */ +static void parse_body(LexState *ls, ExpDesc *e, int needself, BCLine line) +{ + FuncState fs, *pfs = ls->fs; + FuncScope bl; + GCproto *pt; + ptrdiff_t oldbase = pfs->bcbase - ls->bcstack; + fs_init(ls, &fs); + fscope_begin(&fs, &bl, 0); + fs.linedefined = line; + fs.numparams = (uint8_t)parse_params(ls, needself); + fs.bcbase = pfs->bcbase + pfs->pc; + fs.bclim = pfs->bclim - pfs->pc; + bcemit_AD(&fs, BC_FUNCF, 0, 0); /* Placeholder. */ + parse_chunk(ls); + if (ls->tok != TK_end) lex_match(ls, TK_end, TK_function, line); + pt = fs_finish(ls, (ls->lastline = ls->linenumber)); + pfs->bcbase = ls->bcstack + oldbase; /* May have been reallocated. */ + pfs->bclim = (BCPos)(ls->sizebcstack - oldbase); + /* Store new prototype in the constant array of the parent. */ + expr_init(e, VRELOCABLE, + bcemit_AD(pfs, BC_FNEW, 0, const_gc(pfs, obj2gco(pt), LJ_TPROTO))); +#if LJ_HASFFI + pfs->flags |= (fs.flags & PROTO_FFI); +#endif + if (!(pfs->flags & PROTO_CHILD)) { + if (pfs->flags & PROTO_HAS_RETURN) + pfs->flags |= PROTO_FIXUP_RETURN; + pfs->flags |= PROTO_CHILD; + } + lj_lex_next(ls); +} + +/* Parse expression list. Last expression is left open. */ +static BCReg expr_list(LexState *ls, ExpDesc *v) +{ + BCReg n = 1; + expr(ls, v); + while (lex_opt(ls, ',')) { + expr_tonextreg(ls->fs, v); + expr(ls, v); + n++; + } + return n; +} + +/* Parse function argument list. */ +static void parse_args(LexState *ls, ExpDesc *e) +{ + FuncState *fs = ls->fs; + ExpDesc args; + BCIns ins; + BCReg base; + BCLine line = ls->linenumber; + if (ls->tok == '(') { +#if !LJ_52 + if (line != ls->lastline) + err_syntax(ls, LJ_ERR_XAMBIG); +#endif + lj_lex_next(ls); + if (ls->tok == ')') { /* f(). */ + args.k = VVOID; + } else { + expr_list(ls, &args); + if (args.k == VCALL) /* f(a, b, g()) or f(a, b, ...). */ + setbc_b(bcptr(fs, &args), 0); /* Pass on multiple results. */ + } + lex_match(ls, ')', '(', line); + } else if (ls->tok == '{') { + expr_table(ls, &args); + } else if (ls->tok == TK_string) { + expr_init(&args, VKSTR, 0); + args.u.sval = strV(&ls->tokval); + lj_lex_next(ls); + } else { + err_syntax(ls, LJ_ERR_XFUNARG); + return; /* Silence compiler. */ + } + lj_assertFS(e->k == VNONRELOC, "bad expr type %d", e->k); + base = e->u.s.info; /* Base register for call. */ + if (args.k == VCALL) { + ins = BCINS_ABC(BC_CALLM, base, 2, args.u.s.aux - base - 1 - LJ_FR2); + } else { + if (args.k != VVOID) + expr_tonextreg(fs, &args); + ins = BCINS_ABC(BC_CALL, base, 2, fs->freereg - base - LJ_FR2); + } + expr_init(e, VCALL, bcemit_INS(fs, ins)); + e->u.s.aux = base; + fs->bcbase[fs->pc - 1].line = line; + fs->freereg = base+1; /* Leave one result by default. */ +} + +/* Parse primary expression. */ +static void expr_primary(LexState *ls, ExpDesc *v) +{ + FuncState *fs = ls->fs; + /* Parse prefix expression. */ + if (ls->tok == '(') { + BCLine line = ls->linenumber; + lj_lex_next(ls); + expr(ls, v); + lex_match(ls, ')', '(', line); + expr_discharge(ls->fs, v); + } else if (ls->tok == TK_name || (!LJ_52 && ls->tok == TK_goto)) { + var_lookup(ls, v); + } else { + err_syntax(ls, LJ_ERR_XSYMBOL); + } + for (;;) { /* Parse multiple expression suffixes. */ + if (ls->tok == '.') { + expr_field(ls, v); + } else if (ls->tok == '[') { + ExpDesc key; + expr_toanyreg(fs, v); + expr_bracket(ls, &key); + expr_index(fs, v, &key); + } else if (ls->tok == ':') { + ExpDesc key; + lj_lex_next(ls); + expr_str(ls, &key); + bcemit_method(fs, v, &key); + parse_args(ls, v); + } else if (ls->tok == '(' || ls->tok == TK_string || ls->tok == '{') { + expr_tonextreg(fs, v); + if (LJ_FR2) bcreg_reserve(fs, 1); + parse_args(ls, v); + } else { + break; + } + } +} + +/* Parse simple expression. */ +static void expr_simple(LexState *ls, ExpDesc *v) +{ + switch (ls->tok) { + case TK_number: + expr_init(v, (LJ_HASFFI && tviscdata(&ls->tokval)) ? VKCDATA : VKNUM, 0); + copyTV(ls->L, &v->u.nval, &ls->tokval); + break; + case TK_string: + expr_init(v, VKSTR, 0); + v->u.sval = strV(&ls->tokval); + break; + case TK_nil: + expr_init(v, VKNIL, 0); + break; + case TK_true: + expr_init(v, VKTRUE, 0); + break; + case TK_false: + expr_init(v, VKFALSE, 0); + break; + case TK_dots: { /* Vararg. */ + FuncState *fs = ls->fs; + BCReg base; + checkcond(ls, fs->flags & PROTO_VARARG, LJ_ERR_XDOTS); + bcreg_reserve(fs, 1); + base = fs->freereg-1; + expr_init(v, VCALL, bcemit_ABC(fs, BC_VARG, base, 2, fs->numparams)); + v->u.s.aux = base; + break; + } + case '{': /* Table constructor. */ + expr_table(ls, v); + return; + case TK_function: + lj_lex_next(ls); + parse_body(ls, v, 0, ls->linenumber); + return; + default: + expr_primary(ls, v); + return; + } + lj_lex_next(ls); +} + +/* Manage syntactic levels to avoid blowing up the stack. */ +static void synlevel_begin(LexState *ls) +{ + if (++ls->level >= LJ_MAX_XLEVEL) + lj_lex_error(ls, 0, LJ_ERR_XLEVELS); +} + +#define synlevel_end(ls) ((ls)->level--) + +/* Convert token to binary operator. */ +static BinOpr token2binop(LexToken tok) +{ + switch (tok) { + case '+': return OPR_ADD; + case '-': return OPR_SUB; + case '*': return OPR_MUL; + case '/': return OPR_DIV; + case '%': return OPR_MOD; + case '^': return OPR_POW; + case TK_concat: return OPR_CONCAT; + case TK_ne: return OPR_NE; + case TK_eq: return OPR_EQ; + case '<': return OPR_LT; + case TK_le: return OPR_LE; + case '>': return OPR_GT; + case TK_ge: return OPR_GE; + case TK_and: return OPR_AND; + case TK_or: return OPR_OR; + default: return OPR_NOBINOPR; + } +} + +/* Priorities for each binary operator. ORDER OPR. */ +static const struct { + uint8_t left; /* Left priority. */ + uint8_t right; /* Right priority. */ +} priority[] = { + {6,6}, {6,6}, {7,7}, {7,7}, {7,7}, /* ADD SUB MUL DIV MOD */ + {10,9}, {5,4}, /* POW CONCAT (right associative) */ + {3,3}, {3,3}, /* EQ NE */ + {3,3}, {3,3}, {3,3}, {3,3}, /* LT GE GT LE */ + {2,2}, {1,1} /* AND OR */ +}; + +#define UNARY_PRIORITY 8 /* Priority for unary operators. */ + +/* Forward declaration. */ +static BinOpr expr_binop(LexState *ls, ExpDesc *v, uint32_t limit); + +/* Parse unary expression. */ +static void expr_unop(LexState *ls, ExpDesc *v) +{ + BCOp op; + if (ls->tok == TK_not) { + op = BC_NOT; + } else if (ls->tok == '-') { + op = BC_UNM; + } else if (ls->tok == '#') { + op = BC_LEN; + } else { + expr_simple(ls, v); + return; + } + lj_lex_next(ls); + expr_binop(ls, v, UNARY_PRIORITY); + bcemit_unop(ls->fs, op, v); +} + +/* Parse binary expressions with priority higher than the limit. */ +static BinOpr expr_binop(LexState *ls, ExpDesc *v, uint32_t limit) +{ + BinOpr op; + synlevel_begin(ls); + expr_unop(ls, v); + op = token2binop(ls->tok); + while (op != OPR_NOBINOPR && priority[op].left > limit) { + ExpDesc v2; + BinOpr nextop; + lj_lex_next(ls); + bcemit_binop_left(ls->fs, op, v); + /* Parse binary expression with higher priority. */ + nextop = expr_binop(ls, &v2, priority[op].right); + bcemit_binop(ls->fs, op, v, &v2); + op = nextop; + } + synlevel_end(ls); + return op; /* Return unconsumed binary operator (if any). */ +} + +/* Parse expression. */ +static void expr(LexState *ls, ExpDesc *v) +{ + expr_binop(ls, v, 0); /* Priority 0: parse whole expression. */ +} + +/* Assign expression to the next register. */ +static void expr_next(LexState *ls) +{ + ExpDesc e; + expr(ls, &e); + expr_tonextreg(ls->fs, &e); +} + +/* Parse conditional expression. */ +static BCPos expr_cond(LexState *ls) +{ + ExpDesc v; + expr(ls, &v); + if (v.k == VKNIL) v.k = VKFALSE; + bcemit_branch_t(ls->fs, &v); + return v.f; +} + +/* -- Assignments --------------------------------------------------------- */ + +/* List of LHS variables. */ +typedef struct LHSVarList { + ExpDesc v; /* LHS variable. */ + struct LHSVarList *prev; /* Link to previous LHS variable. */ +} LHSVarList; + +/* Eliminate write-after-read hazards for local variable assignment. */ +static void assign_hazard(LexState *ls, LHSVarList *lh, const ExpDesc *v) +{ + FuncState *fs = ls->fs; + BCReg reg = v->u.s.info; /* Check against this variable. */ + BCReg tmp = fs->freereg; /* Rename to this temp. register (if needed). */ + int hazard = 0; + for (; lh; lh = lh->prev) { + if (lh->v.k == VINDEXED) { + if (lh->v.u.s.info == reg) { /* t[i], t = 1, 2 */ + hazard = 1; + lh->v.u.s.info = tmp; + } + if (lh->v.u.s.aux == reg) { /* t[i], i = 1, 2 */ + hazard = 1; + lh->v.u.s.aux = tmp; + } + } + } + if (hazard) { + bcemit_AD(fs, BC_MOV, tmp, reg); /* Rename conflicting variable. */ + bcreg_reserve(fs, 1); + } +} + +/* Adjust LHS/RHS of an assignment. */ +static void assign_adjust(LexState *ls, BCReg nvars, BCReg nexps, ExpDesc *e) +{ + FuncState *fs = ls->fs; + int32_t extra = (int32_t)nvars - (int32_t)nexps; + if (e->k == VCALL) { + extra++; /* Compensate for the VCALL itself. */ + if (extra < 0) extra = 0; + setbc_b(bcptr(fs, e), extra+1); /* Fixup call results. */ + if (extra > 1) bcreg_reserve(fs, (BCReg)extra-1); + } else { + if (e->k != VVOID) + expr_tonextreg(fs, e); /* Close last expression. */ + if (extra > 0) { /* Leftover LHS are set to nil. */ + BCReg reg = fs->freereg; + bcreg_reserve(fs, (BCReg)extra); + bcemit_nil(fs, reg, (BCReg)extra); + } + } + if (nexps > nvars) + ls->fs->freereg -= nexps - nvars; /* Drop leftover regs. */ +} + +/* Recursively parse assignment statement. */ +static void parse_assignment(LexState *ls, LHSVarList *lh, BCReg nvars) +{ + ExpDesc e; + checkcond(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED, LJ_ERR_XSYNTAX); + if (lex_opt(ls, ',')) { /* Collect LHS list and recurse upwards. */ + LHSVarList vl; + vl.prev = lh; + expr_primary(ls, &vl.v); + if (vl.v.k == VLOCAL) + assign_hazard(ls, lh, &vl.v); + checklimit(ls->fs, ls->level + nvars, LJ_MAX_XLEVEL, "variable names"); + parse_assignment(ls, &vl, nvars+1); + } else { /* Parse RHS. */ + BCReg nexps; + lex_check(ls, '='); + nexps = expr_list(ls, &e); + if (nexps == nvars) { + if (e.k == VCALL) { + if (bc_op(*bcptr(ls->fs, &e)) == BC_VARG) { /* Vararg assignment. */ + ls->fs->freereg--; + e.k = VRELOCABLE; + } else { /* Multiple call results. */ + e.u.s.info = e.u.s.aux; /* Base of call is not relocatable. */ + e.k = VNONRELOC; + } + } + bcemit_store(ls->fs, &lh->v, &e); + return; + } + assign_adjust(ls, nvars, nexps, &e); + } + /* Assign RHS to LHS and recurse downwards. */ + expr_init(&e, VNONRELOC, ls->fs->freereg-1); + bcemit_store(ls->fs, &lh->v, &e); +} + +/* Parse call statement or assignment. */ +static void parse_call_assign(LexState *ls) +{ + FuncState *fs = ls->fs; + LHSVarList vl; + expr_primary(ls, &vl.v); + if (vl.v.k == VCALL) { /* Function call statement. */ + setbc_b(bcptr(fs, &vl.v), 1); /* No results. */ + } else { /* Start of an assignment. */ + vl.prev = NULL; + parse_assignment(ls, &vl, 1); + } +} + +/* Parse 'local' statement. */ +static void parse_local(LexState *ls) +{ + if (lex_opt(ls, TK_function)) { /* Local function declaration. */ + ExpDesc v, b; + FuncState *fs = ls->fs; + var_new(ls, 0, lex_str(ls)); + expr_init(&v, VLOCAL, fs->freereg); + v.u.s.aux = fs->varmap[fs->freereg]; + bcreg_reserve(fs, 1); + var_add(ls, 1); + parse_body(ls, &b, 0, ls->linenumber); + /* bcemit_store(fs, &v, &b) without setting VSTACK_VAR_RW. */ + expr_free(fs, &b); + expr_toreg(fs, &b, v.u.s.info); + /* The upvalue is in scope, but the local is only valid after the store. */ + var_get(ls, fs, fs->nactvar - 1).startpc = fs->pc; + } else { /* Local variable declaration. */ + ExpDesc e; + BCReg nexps, nvars = 0; + do { /* Collect LHS. */ + var_new(ls, nvars++, lex_str(ls)); + } while (lex_opt(ls, ',')); + if (lex_opt(ls, '=')) { /* Optional RHS. */ + nexps = expr_list(ls, &e); + } else { /* Or implicitly set to nil. */ + e.k = VVOID; + nexps = 0; + } + assign_adjust(ls, nvars, nexps, &e); + var_add(ls, nvars); + } +} + +/* Parse 'function' statement. */ +static void parse_func(LexState *ls, BCLine line) +{ + FuncState *fs; + ExpDesc v, b; + int needself = 0; + lj_lex_next(ls); /* Skip 'function'. */ + /* Parse function name. */ + var_lookup(ls, &v); + while (ls->tok == '.') /* Multiple dot-separated fields. */ + expr_field(ls, &v); + if (ls->tok == ':') { /* Optional colon to signify method call. */ + needself = 1; + expr_field(ls, &v); + } + parse_body(ls, &b, needself, line); + fs = ls->fs; + bcemit_store(fs, &v, &b); + fs->bcbase[fs->pc - 1].line = line; /* Set line for the store. */ +} + +/* -- Control transfer statements ----------------------------------------- */ + +/* Check for end of block. */ +static int parse_isend(LexToken tok) +{ + switch (tok) { + case TK_else: case TK_elseif: case TK_end: case TK_until: case TK_eof: + return 1; + default: + return 0; + } +} + +/* Parse 'return' statement. */ +static void parse_return(LexState *ls) +{ + BCIns ins; + FuncState *fs = ls->fs; + lj_lex_next(ls); /* Skip 'return'. */ + fs->flags |= PROTO_HAS_RETURN; + if (parse_isend(ls->tok) || ls->tok == ';') { /* Bare return. */ + ins = BCINS_AD(BC_RET0, 0, 1); + } else { /* Return with one or more values. */ + ExpDesc e; /* Receives the _last_ expression in the list. */ + BCReg nret = expr_list(ls, &e); + if (nret == 1) { /* Return one result. */ + if (e.k == VCALL) { /* Check for tail call. */ + BCIns *ip = bcptr(fs, &e); + /* It doesn't pay off to add BC_VARGT just for 'return ...'. */ + if (bc_op(*ip) == BC_VARG) goto notailcall; + fs->pc--; + ins = BCINS_AD(bc_op(*ip)-BC_CALL+BC_CALLT, bc_a(*ip), bc_c(*ip)); + } else { /* Can return the result from any register. */ + ins = BCINS_AD(BC_RET1, expr_toanyreg(fs, &e), 2); + } + } else { + if (e.k == VCALL) { /* Append all results from a call. */ + notailcall: + setbc_b(bcptr(fs, &e), 0); + ins = BCINS_AD(BC_RETM, fs->nactvar, e.u.s.aux - fs->nactvar); + } else { + expr_tonextreg(fs, &e); /* Force contiguous registers. */ + ins = BCINS_AD(BC_RET, fs->nactvar, nret+1); + } + } + } + if (fs->flags & PROTO_CHILD) + bcemit_AJ(fs, BC_UCLO, 0, 0); /* May need to close upvalues first. */ + bcemit_INS(fs, ins); +} + +/* Parse 'break' statement. */ +static void parse_break(LexState *ls) +{ + ls->fs->bl->flags |= FSCOPE_BREAK; + gola_new(ls, NAME_BREAK, VSTACK_GOTO, bcemit_jmp(ls->fs)); +} + +/* Parse 'goto' statement. */ +static void parse_goto(LexState *ls) +{ + FuncState *fs = ls->fs; + GCstr *name = lex_str(ls); + VarInfo *vl = gola_findlabel(ls, name); + if (vl) /* Treat backwards goto within same scope like a loop. */ + bcemit_AJ(fs, BC_LOOP, vl->slot, -1); /* No BC range check. */ + fs->bl->flags |= FSCOPE_GOLA; + gola_new(ls, name, VSTACK_GOTO, bcemit_jmp(fs)); +} + +/* Parse label. */ +static void parse_label(LexState *ls) +{ + FuncState *fs = ls->fs; + GCstr *name; + MSize idx; + fs->lasttarget = fs->pc; + fs->bl->flags |= FSCOPE_GOLA; + lj_lex_next(ls); /* Skip '::'. */ + name = lex_str(ls); + if (gola_findlabel(ls, name)) + lj_lex_error(ls, 0, LJ_ERR_XLDUP, strdata(name)); + idx = gola_new(ls, name, VSTACK_LABEL, fs->pc); + lex_check(ls, TK_label); + /* Recursively parse trailing statements: labels and ';' (Lua 5.2 only). */ + for (;;) { + if (ls->tok == TK_label) { + synlevel_begin(ls); + parse_label(ls); + synlevel_end(ls); + } else if (LJ_52 && ls->tok == ';') { + lj_lex_next(ls); + } else { + break; + } + } + /* Trailing label is considered to be outside of scope. */ + if (parse_isend(ls->tok) && ls->tok != TK_until) + ls->vstack[idx].slot = fs->bl->nactvar; + gola_resolve(ls, fs->bl, idx); +} + +/* -- Blocks, loops and conditional statements ---------------------------- */ + +/* Parse a block. */ +static void parse_block(LexState *ls) +{ + FuncState *fs = ls->fs; + FuncScope bl; + fscope_begin(fs, &bl, 0); + parse_chunk(ls); + fscope_end(fs); +} + +/* Parse 'while' statement. */ +static void parse_while(LexState *ls, BCLine line) +{ + FuncState *fs = ls->fs; + BCPos start, loop, condexit; + FuncScope bl; + lj_lex_next(ls); /* Skip 'while'. */ + start = fs->lasttarget = fs->pc; + condexit = expr_cond(ls); + fscope_begin(fs, &bl, FSCOPE_LOOP); + lex_check(ls, TK_do); + loop = bcemit_AD(fs, BC_LOOP, fs->nactvar, 0); + parse_block(ls); + jmp_patch(fs, bcemit_jmp(fs), start); + lex_match(ls, TK_end, TK_while, line); + fscope_end(fs); + jmp_tohere(fs, condexit); + jmp_patchins(fs, loop, fs->pc); +} + +/* Parse 'repeat' statement. */ +static void parse_repeat(LexState *ls, BCLine line) +{ + FuncState *fs = ls->fs; + BCPos loop = fs->lasttarget = fs->pc; + BCPos condexit; + FuncScope bl1, bl2; + fscope_begin(fs, &bl1, FSCOPE_LOOP); /* Breakable loop scope. */ + fscope_begin(fs, &bl2, 0); /* Inner scope. */ + lj_lex_next(ls); /* Skip 'repeat'. */ + bcemit_AD(fs, BC_LOOP, fs->nactvar, 0); + parse_chunk(ls); + lex_match(ls, TK_until, TK_repeat, line); + condexit = expr_cond(ls); /* Parse condition (still inside inner scope). */ + if (!(bl2.flags & FSCOPE_UPVAL)) { /* No upvalues? Just end inner scope. */ + fscope_end(fs); + } else { /* Otherwise generate: cond: UCLO+JMP out, !cond: UCLO+JMP loop. */ + parse_break(ls); /* Break from loop and close upvalues. */ + jmp_tohere(fs, condexit); + fscope_end(fs); /* End inner scope and close upvalues. */ + condexit = bcemit_jmp(fs); + } + jmp_patch(fs, condexit, loop); /* Jump backwards if !cond. */ + jmp_patchins(fs, loop, fs->pc); + fscope_end(fs); /* End loop scope. */ +} + +/* Parse numeric 'for'. */ +static void parse_for_num(LexState *ls, GCstr *varname, BCLine line) +{ + FuncState *fs = ls->fs; + BCReg base = fs->freereg; + FuncScope bl; + BCPos loop, loopend; + /* Hidden control variables. */ + var_new_fixed(ls, FORL_IDX, VARNAME_FOR_IDX); + var_new_fixed(ls, FORL_STOP, VARNAME_FOR_STOP); + var_new_fixed(ls, FORL_STEP, VARNAME_FOR_STEP); + /* Visible copy of index variable. */ + var_new(ls, FORL_EXT, varname); + lex_check(ls, '='); + expr_next(ls); + lex_check(ls, ','); + expr_next(ls); + if (lex_opt(ls, ',')) { + expr_next(ls); + } else { + bcemit_AD(fs, BC_KSHORT, fs->freereg, 1); /* Default step is 1. */ + bcreg_reserve(fs, 1); + } + var_add(ls, 3); /* Hidden control variables. */ + lex_check(ls, TK_do); + loop = bcemit_AJ(fs, BC_FORI, base, NO_JMP); + fscope_begin(fs, &bl, 0); /* Scope for visible variables. */ + var_add(ls, 1); + bcreg_reserve(fs, 1); + parse_block(ls); + fscope_end(fs); + /* Perform loop inversion. Loop control instructions are at the end. */ + loopend = bcemit_AJ(fs, BC_FORL, base, NO_JMP); + fs->bcbase[loopend].line = line; /* Fix line for control ins. */ + jmp_patchins(fs, loopend, loop+1); + jmp_patchins(fs, loop, fs->pc); +} + +/* Try to predict whether the iterator is next() and specialize the bytecode. +** Detecting next() and pairs() by name is simplistic, but quite effective. +** The interpreter backs off if the check for the closure fails at runtime. +*/ +static int predict_next(LexState *ls, FuncState *fs, BCPos pc) +{ + BCIns ins = fs->bcbase[pc].ins; + GCstr *name; + cTValue *o; + switch (bc_op(ins)) { + case BC_MOV: + name = gco2str(gcref(var_get(ls, fs, bc_d(ins)).name)); + break; + case BC_UGET: + name = gco2str(gcref(ls->vstack[fs->uvmap[bc_d(ins)]].name)); + break; + case BC_GGET: + /* There's no inverse index (yet), so lookup the strings. */ + o = lj_tab_getstr(fs->kt, lj_str_newlit(ls->L, "pairs")); + if (o && tvhaskslot(o) && tvkslot(o) == bc_d(ins)) + return 1; + o = lj_tab_getstr(fs->kt, lj_str_newlit(ls->L, "next")); + if (o && tvhaskslot(o) && tvkslot(o) == bc_d(ins)) + return 1; + return 0; + default: + return 0; + } + return (name->len == 5 && !strcmp(strdata(name), "pairs")) || + (name->len == 4 && !strcmp(strdata(name), "next")); +} + +/* Parse 'for' iterator. */ +static void parse_for_iter(LexState *ls, GCstr *indexname) +{ + FuncState *fs = ls->fs; + ExpDesc e; + BCReg nvars = 0; + BCLine line; + BCReg base = fs->freereg + 3; + BCPos loop, loopend, exprpc = fs->pc; + FuncScope bl; + int isnext; + /* Hidden control variables. */ + var_new_fixed(ls, nvars++, VARNAME_FOR_GEN); + var_new_fixed(ls, nvars++, VARNAME_FOR_STATE); + var_new_fixed(ls, nvars++, VARNAME_FOR_CTL); + /* Visible variables returned from iterator. */ + var_new(ls, nvars++, indexname); + while (lex_opt(ls, ',')) + var_new(ls, nvars++, lex_str(ls)); + lex_check(ls, TK_in); + line = ls->linenumber; + assign_adjust(ls, 3, expr_list(ls, &e), &e); + /* The iterator needs another 3 [4] slots (func [pc] | state ctl). */ + bcreg_bump(fs, 3+LJ_FR2); + isnext = (nvars <= 5 && predict_next(ls, fs, exprpc)); + var_add(ls, 3); /* Hidden control variables. */ + lex_check(ls, TK_do); + loop = bcemit_AJ(fs, isnext ? BC_ISNEXT : BC_JMP, base, NO_JMP); + fscope_begin(fs, &bl, 0); /* Scope for visible variables. */ + var_add(ls, nvars-3); + bcreg_reserve(fs, nvars-3); + parse_block(ls); + fscope_end(fs); + /* Perform loop inversion. Loop control instructions are at the end. */ + jmp_patchins(fs, loop, fs->pc); + bcemit_ABC(fs, isnext ? BC_ITERN : BC_ITERC, base, nvars-3+1, 2+1); + loopend = bcemit_AJ(fs, BC_ITERL, base, NO_JMP); + fs->bcbase[loopend-1].line = line; /* Fix line for control ins. */ + fs->bcbase[loopend].line = line; + jmp_patchins(fs, loopend, loop+1); +} + +/* Parse 'for' statement. */ +static void parse_for(LexState *ls, BCLine line) +{ + FuncState *fs = ls->fs; + GCstr *varname; + FuncScope bl; + fscope_begin(fs, &bl, FSCOPE_LOOP); + lj_lex_next(ls); /* Skip 'for'. */ + varname = lex_str(ls); /* Get first variable name. */ + if (ls->tok == '=') + parse_for_num(ls, varname, line); + else if (ls->tok == ',' || ls->tok == TK_in) + parse_for_iter(ls, varname); + else + err_syntax(ls, LJ_ERR_XFOR); + lex_match(ls, TK_end, TK_for, line); + fscope_end(fs); /* Resolve break list. */ +} + +/* Parse condition and 'then' block. */ +static BCPos parse_then(LexState *ls) +{ + BCPos condexit; + lj_lex_next(ls); /* Skip 'if' or 'elseif'. */ + condexit = expr_cond(ls); + lex_check(ls, TK_then); + parse_block(ls); + return condexit; +} + +/* Parse 'if' statement. */ +static void parse_if(LexState *ls, BCLine line) +{ + FuncState *fs = ls->fs; + BCPos flist; + BCPos escapelist = NO_JMP; + flist = parse_then(ls); + while (ls->tok == TK_elseif) { /* Parse multiple 'elseif' blocks. */ + jmp_append(fs, &escapelist, bcemit_jmp(fs)); + jmp_tohere(fs, flist); + flist = parse_then(ls); + } + if (ls->tok == TK_else) { /* Parse optional 'else' block. */ + jmp_append(fs, &escapelist, bcemit_jmp(fs)); + jmp_tohere(fs, flist); + lj_lex_next(ls); /* Skip 'else'. */ + parse_block(ls); + } else { + jmp_append(fs, &escapelist, flist); + } + jmp_tohere(fs, escapelist); + lex_match(ls, TK_end, TK_if, line); +} + +/* -- Parse statements ---------------------------------------------------- */ + +/* Parse a statement. Returns 1 if it must be the last one in a chunk. */ +static int parse_stmt(LexState *ls) +{ + BCLine line = ls->linenumber; + switch (ls->tok) { + case TK_if: + parse_if(ls, line); + break; + case TK_while: + parse_while(ls, line); + break; + case TK_do: + lj_lex_next(ls); + parse_block(ls); + lex_match(ls, TK_end, TK_do, line); + break; + case TK_for: + parse_for(ls, line); + break; + case TK_repeat: + parse_repeat(ls, line); + break; + case TK_function: + parse_func(ls, line); + break; + case TK_local: + lj_lex_next(ls); + parse_local(ls); + break; + case TK_return: + parse_return(ls); + return 1; /* Must be last. */ + case TK_break: + lj_lex_next(ls); + parse_break(ls); + return !LJ_52; /* Must be last in Lua 5.1. */ +#if LJ_52 + case ';': + lj_lex_next(ls); + break; +#endif + case TK_label: + parse_label(ls); + break; + case TK_goto: + if (LJ_52 || lj_lex_lookahead(ls) == TK_name) { + lj_lex_next(ls); + parse_goto(ls); + break; + } + /* fallthrough */ + default: + parse_call_assign(ls); + break; + } + return 0; +} + +/* A chunk is a list of statements optionally separated by semicolons. */ +static void parse_chunk(LexState *ls) +{ + int islast = 0; + synlevel_begin(ls); + while (!islast && !parse_isend(ls->tok)) { + islast = parse_stmt(ls); + lex_opt(ls, ';'); + lj_assertLS(ls->fs->framesize >= ls->fs->freereg && + ls->fs->freereg >= ls->fs->nactvar, + "bad regalloc"); + ls->fs->freereg = ls->fs->nactvar; /* Free registers after each stmt. */ + } + synlevel_end(ls); +} + +/* Entry point of bytecode parser. */ +GCproto *lj_parse(LexState *ls) +{ + FuncState fs; + FuncScope bl; + GCproto *pt; + lua_State *L = ls->L; +#ifdef LUAJIT_DISABLE_DEBUGINFO + ls->chunkname = lj_str_newlit(L, "="); +#else + ls->chunkname = lj_str_newz(L, ls->chunkarg); +#endif + setstrV(L, L->top, ls->chunkname); /* Anchor chunkname string. */ + incr_top(L); + ls->level = 0; + fs_init(ls, &fs); + fs.linedefined = 0; + fs.numparams = 0; + fs.bcbase = NULL; + fs.bclim = 0; + fs.flags |= PROTO_VARARG; /* Main chunk is always a vararg func. */ + fscope_begin(&fs, &bl, 0); + bcemit_AD(&fs, BC_FUNCV, 0, 0); /* Placeholder. */ + lj_lex_next(ls); /* Read-ahead first token. */ + parse_chunk(ls); + if (ls->tok != TK_eof) + err_token(ls, TK_eof); + pt = fs_finish(ls, ls->linenumber); + L->top--; /* Drop chunkname. */ + lj_assertL(fs.prev == NULL && ls->fs == NULL, "mismatched frame nesting"); + lj_assertL(pt->sizeuv == 0, "toplevel proto has upvalues"); + return pt; +} + |