/*
** $Id: lptypes.h,v 1.8 2013/04/12 16:26:38 roberto Exp $
** LPeg - PEG pattern matching for Lua
** Copyright 2007, Lua.org & PUC-Rio (see 'lpeg.html' for license)
** written by Roberto Ierusalimschy
*/
#if !defined(lptypes_h)
#define lptypes_h
#if !defined(LPEG_DEBUG)
#define NDEBUG
#endif
#include <assert.h>
#include <limits.h>
#include "lua.h"
#define VERSION "0.12"
#define PATTERN_T "lpeg-pattern"
#define MAXSTACKIDX "lpeg-maxstack"
/*
** compatibility with Lua 5.2
*/
#if (LUA_VERSION_NUM == 502)
#undef lua_equal
#define lua_equal(L,idx1,idx2) lua_compare(L,(idx1),(idx2),LUA_OPEQ)
#undef lua_getfenv
#define lua_getfenv lua_getuservalue
#undef lua_setfenv
#define lua_setfenv lua_setuservalue
#undef lua_objlen
#define lua_objlen lua_rawlen
#undef luaL_register
#define luaL_register(L,n,f) \
{ if ((n) == NULL) luaL_setfuncs(L,f,0); else luaL_newlib(L,f); }
#endif
/* default maximum size for call/backtrack stack */
#if !defined(MAXBACK)
#define MAXBACK 100
#endif
/* maximum number of rules in a grammar */
#define MAXRULES 200
/* initial size for capture's list */
#define INITCAPSIZE 32
/* index, on Lua stack, for subject */
#define SUBJIDX 2
/* number of fixed arguments to 'match' (before capture arguments) */
#define FIXEDARGS 3
/* index, on Lua stack, for capture list */
#define caplistidx(ptop) ((ptop) + 2)
/* index, on Lua stack, for pattern's ktable */
#define ktableidx(ptop) ((ptop) + 3)
/* index, on Lua stack, for backtracking stack */
#define stackidx(ptop) ((ptop) + 4)
typedef unsigned char byte;
#define BITSPERCHAR 8
#define CHARSETSIZE ((UCHAR_MAX/BITSPERCHAR) + 1)
typedef struct Charset {
byte cs[CHARSETSIZE];
} Charset;
#define loopset(v,b) { int v; for (v = 0; v < CHARSETSIZE; v++) {b;} }
/* access to charset */
#define treebuffer(t) ((byte *)((t) + 1))
/* number of slots needed for 'n' bytes */
#define bytes2slots(n) (((n) - 1) / sizeof(TTree) + 1)
/* set 'b' bit in charset 'cs' */
#define setchar(cs,b) ((cs)[(b) >> 3] |= (1 << ((b) & 7)))
/*
** in capture instructions, 'kind' of capture and its offset are
** packed in field 'aux', 4 bits for each
*/
#define getkind(op) ((op)->i.aux & 0xF)
#define getoff(op) (((op)->i.aux >> 4) & 0xF)
#define joinkindoff(k,o) ((k) | ((o) << 4))
#define MAXOFF 0xF
#define MAXAUX 0xFF
/* maximum number of bytes to look behind */
#define MAXBEHIND MAXAUX
/* maximum size (in elements) for a pattern */
#define MAXPATTSIZE (SHRT_MAX - 10)
/* size (in elements) for an instruction plus extra l bytes */
#define instsize(l) (((l) + sizeof(Instruction) - 1)/sizeof(Instruction) + 1)
/* size (in elements) for a ISet instruction */
#define CHARSETINSTSIZE instsize(CHARSETSIZE)
/* size (in elements) for a IFunc instruction */
#define funcinstsize(p) ((p)->i.aux + 2)
#define testchar(st,c) (((int)(st)[((c) >> 3)] & (1 << ((c) & 7))))
#endif
/*
** $Id: lptree.h,v 1.2 2013/03/24 13:51:12 roberto Exp $
*/
#if !defined(lptree_h)
#define lptree_h
/*
** types of trees
*/
typedef enum TTag {
TChar = 0, TSet, TAny, /* standard PEG elements */
TTrue, TFalse,
TRep,
TSeq, TChoice,
TNot, TAnd,
TCall,
TOpenCall,
TRule, /* sib1 is rule's pattern, sib2 is 'next' rule */
TGrammar, /* sib1 is initial (and first) rule */
TBehind, /* match behind */
TCapture, /* regular capture */
TRunTime /* run-time capture */
} TTag;
/* number of siblings for each tree */
extern const byte numsiblings[];
/*
** Tree trees
** The first sibling of a tree (if there is one) is immediately after
** the tree. A reference to a second sibling (ps) is its position
** relative to the position of the tree itself. A key in ktable
** uses the (unique) address of the original tree that created that
** entry. NULL means no data.
*/
typedef struct TTree {
byte tag;
byte cap; /* kind of capture (if it is a capture) */
unsigned short key; /* key in ktable for Lua data (0 if no key) */
union {
int ps; /* occasional second sibling */
int n; /* occasional counter */
} u;
} TTree;
/*
** A complete pattern has its tree plus, if already compiled,
** its corresponding code
*/
typedef struct Pattern {
union Instruction *code;
int codesize;
TTree tree[1];
} Pattern;
/* number of siblings for each tree */
extern const byte numsiblings[];
/* access to siblings */
#define sib1(t) ((t) + 1)
#define sib2(t) ((t) + (t)->u.ps)
#endif
/*
** $Id: lpcap.h,v 1.1 2013/03/21 20:25:12 roberto Exp $
*/
#if !defined(lpcap_h)
#define lpcap_h
/* kinds of captures */
typedef enum CapKind {
Cclose, Cposition, Cconst, Cbackref, Carg, Csimple, Ctable, Cfunction,
Cquery, Cstring, Cnum, Csubst, Cfold, Cruntime, Cgroup
} CapKind;
typedef struct Capture {
const char *s; /* subject position */
short idx; /* extra info about capture (group name, arg index, etc.) */
byte kind; /* kind of capture */
byte siz; /* size of full capture + 1 (0 = not a full capture) */
} Capture;
typedef struct CapState {
Capture *cap; /* current capture */
Capture *ocap; /* (original) capture list */
lua_State *L;
int ptop; /* index of last argument to 'match' */
const char *s; /* original string */
int valuecached; /* value stored in cache slot */
} CapState;
int runtimecap (CapState *cs, Capture *close, const char *s, int *rem);
int getcaptures (lua_State *L, const char *s, const char *r, int ptop);
int finddyncap (Capture *cap, Capture *last);
#endif
/*
** $Id: lpvm.h,v 1.2 2013/04/03 20:37:18 roberto Exp $
*/
#if !defined(lpvm_h)
#define lpvm_h
/* Virtual Machine's instructions */
typedef enum Opcode {
IAny, /* if no char, fail */
IChar, /* if char != aux, fail */
ISet, /* if char not in buff, fail */
ITestAny, /* in no char, jump to 'offset' */
ITestChar, /* if char != aux, jump to 'offset' */
ITestSet, /* if char not in buff, jump to 'offset' */
ISpan, /* read a span of chars in buff */
IBehind, /* walk back 'aux' characters (fail if not possible) */
IRet, /* return from a rule */
IEnd, /* end of pattern */
IChoice, /* stack a choice; next fail will jump to 'offset' */
IJmp, /* jump to 'offset' */
ICall, /* call rule at 'offset' */
IOpenCall, /* call rule number 'key' (must be closed to a ICall) */
ICommit, /* pop choice and jump to 'offset' */
IPartialCommit, /* update top choice to current position and jump */
IBackCommit, /* "fails" but jump to its own 'offset' */
IFailTwice, /* pop one choice and then fail */
IFail, /* go back to saved state on choice and jump to saved offset */
IGiveup, /* internal use */
IFullCapture, /* complete capture of last 'off' chars */
IOpenCapture, /* start a capture */
ICloseCapture,
ICloseRunTime
} Opcode;
typedef union Instruction {
struct Inst {
byte code;
byte aux;
short key;
} i;
int offset;
byte buff[1];
} Instruction;
int getposition (lua_State *L, int t, int i);
void printpatt (Instruction *p, int n);
const char *match (lua_State *L, const char *o, const char *s, const char *e,
Instruction *op, Capture *capture, int ptop);
int verify (lua_State *L, Instruction *op, const Instruction *p,
Instruction *e, int postable, int rule);
void checkrule (lua_State *L, Instruction *op, int from, int to,
int postable, int rule);
#endif
/*
** $Id: lpcode.h,v 1.5 2013/04/04 21:24:45 roberto Exp $
*/
#if !defined(lpcode_h)
#define lpcode_h
#include "lua.h"
int tocharset (TTree *tree, Charset *cs);
int checkaux (TTree *tree, int pred);
int fixedlenx (TTree *tree, int count, int len);
int hascaptures (TTree *tree);
int lp_gc (lua_State *L);
Instruction *compile (lua_State *L, Pattern *p);
void reallocprog (lua_State *L, Pattern *p, int nsize);
int sizei (const Instruction *i);
#define PEnullable 0
#define PEnofail 1
#define nofail(t) checkaux(t, PEnofail)
#define nullable(t) checkaux(t, PEnullable)
#define fixedlen(t) fixedlenx(t, 0, 0)
#endif
/*
** $Id: lpprint.h,v 1.1 2013/03/21 20:25:12 roberto Exp $
*/
#if !defined(lpprint_h)
#define lpprint_h
#if defined(LPEG_DEBUG)
void printpatt (Instruction *p, int n);
void printtree (TTree *tree, int ident);
void printktable (lua_State *L, int idx);
void printcharset (const byte *st);
void printcaplist (Capture *cap, Capture *limit);
#else
#define printktable(L,idx) \
luaL_error(L, "function only implemented in debug mode")
#define printtree(tree,i) \
luaL_error(L, "function only implemented in debug mode")
#define printpatt(p,n) \
luaL_error(L, "function only implemented in debug mode")
#endif
#endif
/*
** $Id: lpcap.c,v 1.4 2013/03/21 20:25:12 roberto Exp $
** Copyright 2007, Lua.org & PUC-Rio (see 'lpeg.html' for license)
*/
#include "lua.h"
#include "lauxlib.h"
#define captype(cap) ((cap)->kind)
#define isclosecap(cap) (captype(cap) == Cclose)
#define closeaddr(c) ((c)->s + (c)->siz - 1)
#define isfullcap(cap) ((cap)->siz != 0)
#define getfromktable(cs,v) lua_rawgeti((cs)->L, ktableidx((cs)->ptop), v)
#define pushluaval(cs) getfromktable(cs, (cs)->cap->idx)
/*
** Put at the cache for Lua values the value indexed by 'v' in ktable
** of the running pattern (if it is not there yet); returns its index.
*/
static int updatecache (CapState *cs, int v) {
int idx = cs->ptop + 1; /* stack index of cache for Lua values */
if (v != cs->valuecached) { /* not there? */
getfromktable(cs, v); /* get value from 'ktable' */
lua_replace(cs->L, idx); /* put it at reserved stack position */
cs->valuecached = v; /* keep track of what is there */
}
return idx;
}
static int pushcapture (CapState *cs);
/*
** Goes back in a list of captures looking for an open capture
** corresponding to a close
*/
static Capture *findopen (Capture *cap) {
int n = 0; /* number of closes waiting an open */
for (;;) {
cap--;
if (isclosecap(cap)) n++; /* one more open to skip */
else if (!isfullcap(cap))
if (n-- == 0) return cap;
}
}
/*
** Go to the next capture
*/
static void nextcap (CapState *cs) {
Capture *cap = cs->cap;
if (!isfullcap(cap)) { /* not a single capture? */
int n = 0; /* number of opens waiting a close */
for (;;) { /* look for corresponding close */
cap++;
if (isclosecap(cap)) {
if (n-- == 0) break;
}
else if (!isfullcap(cap)) n++;
}
}
cs->cap = cap + 1; /* + 1 to skip last close (or entire single capture) */
}
/*
** Push on the Lua stack all values generated by nested captures inside
** the current capture. Returns number of values pushed. 'addextra'
** makes it push the entire match after all captured values. The
** entire match is pushed also if there are no other nested values,
** so the function never returns zero.
*/
static int pushnestedvalues (CapState *cs, int addextra) {
Capture *co = cs->cap;
if (isfullcap(cs->cap++)) { /* no nested captures? */
lua_pushlstring(cs->L, co->s, co->siz - 1); /* push whole match */
return 1; /* that is it */
}
else {
int n = 0;
while (!isclosecap(cs->cap)) /* repeat for all nested patterns */
n += pushcapture(cs);
if (addextra || n == 0) { /* need extra? */
lua_pushlstring(cs->L, co->s, cs->cap->s - co->s); /* push whole match */
n++;
}
cs->cap++; /* skip close entry */
return n;
}
}
/*
** Push only the first value generated by nested captures
*/
static void pushonenestedvalue (CapState *cs) {
int n = pushnestedvalues(cs, 0);
if (n > 1)
lua_pop(cs->L, n - 1); /* pop extra values */
}
/*
** Try to find a named group capture with the name given at the top of
** the stack; goes backward from 'cap'.
*/
static Capture *findback (CapState *cs, Capture *cap) {
lua_State *L = cs->L;
while (cap-- > cs->ocap) { /* repeat until end of list */
if (isclosecap(cap))
cap = findopen(cap); /* skip nested captures */
else if (!isfullcap(cap))
continue; /* opening an enclosing capture: skip and get previous */
if (captype(cap) == Cgroup) {
getfromktable(cs, cap->idx); /* get group name */
if (lua_equal(L, -2, -1)) { /* right group? */
lua_pop(L, 2); /* remove reference name and group name */
return cap;
}
else lua_pop(L, 1); /* remove group name */
}
}
luaL_error(L, "back reference '%s' not found", lua_tostring(L, -1));
return NULL; /* to avoid warnings */
}
/*
** Back-reference capture. Return number of values pushed.
*/
static int backrefcap (CapState *cs) {
int n;
Capture *curr = cs->cap;
pushluaval(cs); /* reference name */
cs->cap = findback(cs, curr); /* find corresponding group */
n = pushnestedvalues(cs, 0); /* push group's values */
cs->cap = curr + 1;
return n;
}
/*
** Table capture: creates a new table and populates it with nested
** captures.
*/
static int tablecap (CapState *cs) {
lua_State *L = cs->L;
int n = 0;
lua_newtable(L);
if (isfullcap(cs->cap++))
return 1; /* table is empty */
while (!isclosecap(cs->cap)) {
if (captype(cs->cap) == Cgroup && cs->cap->idx != 0) { /* named group? */
pushluaval(cs); /* push group name */
pushonenestedvalue(cs);
lua_settable(L, -3);
}
else { /* not a named group */
int i;
int k = pushcapture(cs);
for (i = k; i > 0; i--) /* store all values into table */
lua_rawseti(L, -(i + 1), n + i);
n += k;
}
}
cs->cap++; /* skip close entry */
return 1; /* number of values pushed (only the table) */
}
/*
** Table-query capture
*/
static int querycap (CapState *cs) {
int idx = cs->cap->idx;
pushonenestedvalue(cs); /* get nested capture */
lua_gettable(cs->L, updatecache(cs, idx)); /* query cap. value at table */
if (!lua_isnil(cs->L, -1))
return 1;
else { /* no value */
lua_pop(cs->L, 1); /* remove nil */
return 0;
}
}
/*
** Fold capture
*/
static int foldcap (CapState *cs) {
int n;
lua_State *L = cs->L;
int idx = cs->cap->idx;
if (isfullcap(cs->cap++) || /* no nested captures? */
isclosecap(cs->cap) || /* no nested captures (large subject)? */
(n = pushcapture(cs)) == 0) /* nested captures with no values? */
return luaL_error(L, "no initial value for fold capture");
if (n > 1)
lua_pop(L, n - 1); /* leave only one result for accumulator */
while (!isclosecap(cs->cap)) {
lua_pushvalue(L, updatecache(cs, idx)); /* get folding function */
lua_insert(L, -2); /* put it before accumulator */
n = pushcapture(cs); /* get next capture's values */
lua_call(L, n + 1, 1); /* call folding function */
}
cs->cap++; /* skip close entry */
return 1; /* only accumulator left on the stack */
}
/*
** Function capture
*/
static int functioncap (CapState *cs) {
int n;
int top = lua_gettop(cs->L);
pushluaval(cs); /* push function */
n = pushnestedvalues(cs, 0); /* push nested captures */
lua_call(cs->L, n, LUA_MULTRET); /* call function */
return lua_gettop(cs->L) - top; /* return function's results */
}
/*
** Select capture
*/
static int numcap (CapState *cs) {
int idx = cs->cap->idx; /* value to select */
if (idx == 0) { /* no values? */
nextcap(cs); /* skip entire capture */
return 0; /* no value produced */
}
else {
int n = pushnestedvalues(cs, 0);
if (n < idx) /* invalid index? */
return luaL_error(cs->L, "no capture '%d'", idx);
else {
lua_pushvalue(cs->L, -(n - idx + 1)); /* get selected capture */
lua_replace(cs->L, -(n + 1)); /* put it in place of 1st capture */
lua_pop(cs->L, n - 1); /* remove other captures */
return 1;
}
}
}
/*
** Return the stack index of the first runtime capture in the given
** list of captures (or zero if no runtime captures)
*/
int finddyncap (Capture *cap, Capture *last) {
for (; cap < last; cap++) {
if (cap->kind == Cruntime)
return cap->idx; /* stack position of first capture */
}
return 0; /* no dynamic captures in this segment */
}
/*
** Calls a runtime capture. Returns number of captures removed by
** the call, including the initial Cgroup. (Captures to be added are
** on the Lua stack.)
*/
int runtimecap (CapState *cs, Capture *close, const char *s, int *rem) {
int n, id;
lua_State *L = cs->L;
int otop = lua_gettop(L);
Capture *open = findopen(close);
assert(captype(open) == Cgroup);
id = finddyncap(open, close); /* get first dynamic capture argument */
close->kind = Cclose; /* closes the group */
close->s = s;
cs->cap = open; cs->valuecached = 0; /* prepare capture state */
luaL_checkstack(L, 4, "too many runtime captures");
pushluaval(cs); /* push function to be called */
lua_pushvalue(L, SUBJIDX); /* push original subject */
lua_pushinteger(L, s - cs->s + 1); /* push current position */
n = pushnestedvalues(cs, 0); /* push nested captures */
lua_call(L, n + 2, LUA_MULTRET); /* call dynamic function */
if (id > 0) { /* are there old dynamic captures to be removed? */
int i;
for (i = id; i <= otop; i++)
lua_remove(L, id); /* remove old dynamic captures */
*rem = otop - id + 1; /* total number of dynamic captures removed */
}
else
*rem = 0; /* no dynamic captures removed */
return close - open; /* number of captures of all kinds removed */
}
/*
** Auxiliary structure for substitution and string captures: keep
** information about nested captures for future use, avoiding to push
** string results into Lua
*/
typedef struct StrAux {
int isstring; /* whether capture is a string */
union {
Capture *cp; /* if not a string, respective capture */
struct { /* if it is a string... */
const char *s; /* ... starts here */
const char *e; /* ... ends here */
} s;
} u;
} StrAux;
#define MAXSTRCAPS 10
/*
** Collect values from current capture into array 'cps'. Current
** capture must be Cstring (first call) or Csimple (recursive calls).
** (In first call, fills %0 with whole match for Cstring.)
** Returns number of elements in the array that were filled.
*/
static int getstrcaps (CapState *cs, StrAux *cps, int n) {
int k = n++;
cps[k].isstring = 1; /* get string value */
cps[k].u.s.s = cs->cap->s; /* starts here */
if (!isfullcap(cs->cap++)) { /* nested captures? */
while (!isclosecap(cs->cap)) { /* traverse them */
if (n >= MAXSTRCAPS) /* too many captures? */
nextcap(cs); /* skip extra captures (will not need them) */
else if (captype(cs->cap) == Csimple) /* string? */
n = getstrcaps(cs, cps, n); /* put info. into array */
else {
cps[n].isstring = 0; /* not a string */
cps[n].u.cp = cs->cap; /* keep original capture */
nextcap(cs);
n++;
}
}
cs->cap++; /* skip close */
}
cps[k].u.s.e = closeaddr(cs->cap - 1); /* ends here */
return n;
}
/*
** add next capture value (which should be a string) to buffer 'b'
*/
static int addonestring (luaL_Buffer *b, CapState *cs, const char *what);
/*
** String capture: add result to buffer 'b' (instead of pushing
** it into the stack)
*/
static void stringcap (luaL_Buffer *b, CapState *cs) {
StrAux cps[MAXSTRCAPS];
int n;
size_t len, i;
const char *fmt; /* format string */
fmt = lua_tolstring(cs->L, updatecache(cs, cs->cap->idx), &len);
n = getstrcaps(cs, cps, 0) - 1; /* collect nested captures */
for (i = 0; i < len; i++) { /* traverse them */
if (fmt[i] != '%') /* not an escape? */
luaL_addchar(b, fmt[i]); /* add it to buffer */
else if (fmt[++i] < '0' || fmt[i] > '9') /* not followed by a digit? */
luaL_addchar(b, fmt[i]); /* add to buffer */
else {
int l = fmt[i] - '0'; /* capture index */
if (l > n)
luaL_error(cs->L, "invalid capture index (%d)", l);
else if (cps[l].isstring)
luaL_addlstring(b, cps[l].u.s.s, cps[l].u.s.e - cps[l].u.s.s);
else {
Capture *curr = cs->cap;
cs->cap = cps[l].u.cp; /* go back to evaluate that nested capture */
if (!addonestring(b, cs, "capture"))
luaL_error(cs->L, "no values in capture index %d", l);
cs->cap = curr; /* continue from where it stopped */
}
}
}
}
/*
** Substitution capture: add result to buffer 'b'
*/
static void substcap (luaL_Buffer *b, CapState *cs) {
const char *curr = cs->cap->s;
if (isfullcap(cs->cap)) /* no nested captures? */
luaL_addlstring(b, curr, cs->cap->siz - 1); /* keep original text */
else {
cs->cap++; /* skip open entry */
while (!isclosecap(cs->cap)) { /* traverse nested captures */
const char *next = cs->cap->s;
luaL_addlstring(b, curr, next - curr); /* add text up to capture */
if (addonestring(b, cs, "replacement"))
curr = closeaddr(cs->cap - 1); /* continue after match */
else /* no capture value */
curr = next; /* keep original text in final result */
}
luaL_addlstring(b, curr, cs->cap->s - curr); /* add last piece of text */
}
cs->cap++; /* go to next capture */
}
/*
** Evaluates a capture and adds its first value to buffer 'b'; returns
** whether there was a value
*/
static int addonestring (luaL_Buffer *b, CapState *cs, const char *what) {
switch (captype(cs->cap)) {
case Cstring:
stringcap(b, cs); /* add capture directly to buffer */
return 1;
case Csubst:
substcap(b, cs); /* add capture directly to buffer */
return 1;
default: {
lua_State *L = cs->L;
int n = pushcapture(cs);
if (n > 0) {
if (n > 1) lua_pop(L, n - 1); /* only one result */
if (!lua_isstring(L, -1))
luaL_error(L, "invalid %s value (a %s)", what, luaL_typename(L, -1));
luaL_addvalue(b);
}
return n;
}
}
}
/*
** Push all values of the current capture into the stack; returns
** number of values pushed
*/
static int pushcapture (CapState *cs) {
lua_State *L = cs->L;
luaL_checkstack(L, 4, "too many captures");
switch (captype(cs->cap)) {
case Cposition: {
lua_pushinteger(L, cs->cap->s - cs->s + 1);
cs->cap++;
return 1;
}
case Cconst: {
pushluaval(cs);
cs->cap++;
return 1;
}
case Carg: {
int arg = (cs->cap++)->idx;
if (arg + FIXEDARGS > cs->ptop)
return luaL_error(L, "reference to absent argument #%d", arg);
lua_pushvalue(L, arg + FIXEDARGS);
return 1;
}
case Csimple: {
int k = pushnestedvalues(cs, 1);
lua_insert(L, -k); /* make whole match be first result */
return k;
}
case Cruntime: {
lua_pushvalue(L, (cs->cap++)->idx); /* value is in the stack */
return 1;
}
case Cstring: {
luaL_Buffer b;
luaL_buffinit(L, &b);
stringcap(&b, cs);
luaL_pushresult(&b);
return 1;
}
case Csubst: {
luaL_Buffer b;
luaL_buffinit(L, &b);
substcap(&b, cs);
luaL_pushresult(&b);
return 1;
}
case Cgroup: {
if (cs->cap->idx == 0) /* anonymous group? */
return pushnestedvalues(cs, 0); /* add all nested values */
else { /* named group: add no values */
nextcap(cs); /* skip capture */
return 0;
}
}
case Cbackref: return backrefcap(cs);
case Ctable: return tablecap(cs);
case Cfunction: return functioncap(cs);
case Cnum: return numcap(cs);
case Cquery: return querycap(cs);
case Cfold: return foldcap(cs);
default: assert(0); return 0;
}
}
/*
** Prepare a CapState structure and traverse the entire list of
** captures in the stack pushing its results. 's' is the subject
** string, 'r' is the final position of the match, and 'ptop'
** the index in the stack where some useful values were pushed.
** Returns the number of results pushed. (If the list produces no
** results, push the final position of the match.)
*/
int getcaptures (lua_State *L, const char *s, const char *r, int ptop) {
Capture *capture = (Capture *)lua_touserdata(L, caplistidx(ptop));
int n = 0;
if (!isclosecap(capture)) { /* is there any capture? */
CapState cs;
cs.ocap = cs.cap = capture; cs.L = L;
cs.s = s; cs.valuecached = 0; cs.ptop = ptop;
do { /* collect their values */
n += pushcapture(&cs);
} while (!isclosecap(cs.cap));
}
if (n == 0) { /* no capture values? */
lua_pushinteger(L, r - s + 1); /* return only end position */
n = 1;
}
return n;
}
/*
** $Id: lpcode.c,v 1.18 2013/04/12 16:30:33 roberto Exp $
** Copyright 2007, Lua.org & PUC-Rio (see 'lpeg.html' for license)
*/
#include <limits.h>
#include "lua.h"
#include "lauxlib.h"
/* signals a "no-instruction */
#define NOINST -1
static const Charset fullset_ =
{{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}};
static const Charset *fullset = &fullset_;
/*
** {======================================================
** Analysis and some optimizations
** =======================================================
*/
/*
** Check whether a charset is empty (IFail), singleton (IChar),
** full (IAny), or none of those (ISet).
*/
static Opcode charsettype (const byte *cs, int *c) {
int count = 0;
int i;
int candidate = -1; /* candidate position for a char */
for (i = 0; i < CHARSETSIZE; i++) {
int b = cs[i];
if (b == 0) {
if (count > 1) return ISet; /* else set is still empty */
}
else if (b == 0xFF) {
if (count < (i * BITSPERCHAR))
return ISet;
else count += BITSPERCHAR; /* set is still full */
}
else if ((b & (b - 1)) == 0) { /* byte has only one bit? */
if (count > 0)
return ISet; /* set is neither full nor empty */
else { /* set has only one char till now; track it */
count++;
candidate = i;
}
}
else return ISet; /* byte is neither empty, full, nor singleton */
}
switch (count) {
case 0: return IFail; /* empty set */
case 1: { /* singleton; find character bit inside byte */
int b = cs[candidate];
*c = candidate * BITSPERCHAR;
if ((b & 0xF0) != 0) { *c += 4; b >>= 4; }
if ((b & 0x0C) != 0) { *c += 2; b >>= 2; }
if ((b & 0x02) != 0) { *c += 1; }
return IChar;
}
default: {
assert(count == CHARSETSIZE * BITSPERCHAR); /* full set */
return IAny;
}
}
}
/*
** A few basic operations on Charsets
*/
static void cs_complement (Charset *cs) {
loopset(i, cs->cs[i] = ~cs->cs[i]);
}
static int cs_equal (const byte *cs1, const byte *cs2) {
loopset(i, if (cs1[i] != cs2[i]) return 0);
return 1;
}
/*
** computes whether sets cs1 and cs2 are disjoint
*/
static int cs_disjoint (const Charset *cs1, const Charset *cs2) {
loopset(i, if ((cs1->cs[i] & cs2->cs[i]) != 0) return 0;)
return 1;
}
/*
** Convert a 'char' pattern (TSet, TChar, TAny) to a charset
*/
int tocharset (TTree *tree, Charset *cs) {
switch (tree->tag) {
case TSet: { /* copy set */
loopset(i, cs->cs[i] = treebuffer(tree)[i]);
return 1;
}
case TChar: { /* only one char */
assert(0 <= tree->u.n && tree->u.n <= UCHAR_MAX);
loopset(i, cs->cs[i] = 0); /* erase all chars */
setchar(cs->cs, tree->u.n); /* add that one */
return 1;
}
case TAny: {
loopset(i, cs->cs[i] = 0xFF); /* add all to the set */
return 1;
}
default: return 0;
}
}
/*
** Checks whether a pattern has captures
*/
int hascaptures (TTree *tree) {
tailcall:
switch (tree->tag) {
case TCapture: case TRunTime:
return 1;
default: {
switch (numsiblings[tree->tag]) {
case 1: /* return hascaptures(sib1(tree)); */
tree = sib1(tree); goto tailcall;
case 2:
if (hascaptures(sib1(tree))) return 1;
/* else return hascaptures(sib2(tree)); */
tree = sib2(tree); goto tailcall;
default: assert(numsiblings[tree->tag] == 0); return 0;
}
}
}
}
/*
** Checks how a pattern behaves regarding the empty string,
** in one of two different ways:
** A pattern is *nullable* if it can match without consuming any character;
** A pattern is *nofail* if it never fails for any string
** (including the empty string).
** The difference is only for predicates and run-time captures;
** for other patterns, the two properties are equivalent.
** (With predicates, &'a' is nullable but not nofail. Of course,
** nofail => nullable.)
** These functions are all convervative in the following way:
** p is nullable => nullable(p)
** nofail(p) => p cannot fail
** The function assumes that TOpenCall is not nullable;
** this will be checked again when the grammar is fixed.)
** Run-time captures can do whatever they want, so the result
** is conservative.
*/
int checkaux (TTree *tree, int pred) {
tailcall:
switch (tree->tag) {
case TChar: case TSet: case TAny:
case TFalse: case TOpenCall:
return 0; /* not nullable */
case TRep: case TTrue:
return 1; /* no fail */
case TNot: case TBehind: /* can match empty, but can fail */
if (pred == PEnofail) return 0;
else return 1; /* PEnullable */
case TAnd: /* can match empty; fail iff body does */
if (pred == PEnullable) return 1;
/* else return checkaux(sib1(tree), pred); */
tree = sib1(tree); goto tailcall;
case TRunTime: /* can fail; match empty iff body does */
if (pred == PEnofail) return 0;
/* else return checkaux(sib1(tree), pred); */
tree = sib1(tree); goto tailcall;
case TSeq:
if (!checkaux(sib1(tree), pred)) return 0;
/* else return checkaux(sib2(tree), pred); */
tree = sib2(tree); goto tailcall;
case TChoice:
if (checkaux(sib2(tree), pred)) return 1;
/* else return checkaux(sib1(tree), pred); */
tree = sib1(tree); goto tailcall;
case TCapture: case TGrammar: case TRule:
/* return checkaux(sib1(tree), pred); */
tree = sib1(tree); goto tailcall;
case TCall: /* return checkaux(sib2(tree), pred); */
tree = sib2(tree); goto tailcall;
default: assert(0); return 0;
};
}
/*
** number of characters to match a pattern (or -1 if variable)
** ('count' avoids infinite loops for grammars)
*/
int fixedlenx (TTree *tree, int count, int len) {
tailcall:
switch (tree->tag) {
case TChar: case TSet: case TAny:
return len + 1;
case TFalse: case TTrue: case TNot: case TAnd: case TBehind:
return len;
case TRep: case TRunTime: case TOpenCall:
return -1;
case TCapture: case TRule: case TGrammar:
/* return fixedlenx(sib1(tree), count); */
tree = sib1(tree); goto tailcall;
case TCall:
if (count++ >= MAXRULES)
return -1; /* may be a loop */
/* else return fixedlenx(sib2(tree), count); */
tree = sib2(tree); goto tailcall;
case TSeq: {
len = fixedlenx(sib1(tree), count, len);
if (len < 0) return -1;
/* else return fixedlenx(sib2(tree), count, len); */
tree = sib2(tree); goto tailcall;
}
case TChoice: {
int n1, n2;
n1 = fixedlenx(sib1(tree), count, len);
if (n1 < 0) return -1;
n2 = fixedlenx(sib2(tree), count, len);
if (n1 == n2) return n1;
else return -1;
}
default: assert(0); return 0;
};
}
/*
** Computes the 'first set' of a pattern.
** The result is a conservative aproximation:
** match p ax -> x' for some x ==> a in first(p).
** The set 'follow' is the first set of what follows the
** pattern (full set if nothing follows it).
** The function returns 0 when this set can be used for
** tests that avoid the pattern altogether.
** A non-zero return can happen for two reasons:
** 1) match p '' -> '' ==> returns 1.
** (tests cannot be used because they always fail for an empty input)
** 2) there is a match-time capture ==> returns 2.
** (match-time captures should not be avoided by optimizations)
*/
static int getfirst (TTree *tree, const Charset *follow, Charset *firstset) {
tailcall:
switch (tree->tag) {
case TChar: case TSet: case TAny: {
tocharset(tree, firstset);
return 0;
}
case TTrue: {
loopset(i, firstset->cs[i] = follow->cs[i]);
return 1;
}
case TFalse: {
loopset(i, firstset->cs[i] = 0);
return 0;
}
case TChoice: {
Charset csaux;
int e1 = getfirst(sib1(tree), follow, firstset);
int e2 = getfirst(sib2(tree), follow, &csaux);
loopset(i, firstset->cs[i] |= csaux.cs[i]);
return e1 | e2;
}
case TSeq: {
if (!nullable(sib1(tree))) {
/* return getfirst(sib1(tree), fullset, firstset); */
tree = sib1(tree); follow = fullset; goto tailcall;
}
else { /* FIRST(p1 p2, fl) = FIRST(p1, FIRST(p2, fl)) */
Charset csaux;
int e2 = getfirst(sib2(tree), follow, &csaux);
int e1 = getfirst(sib1(tree), &csaux, firstset);
if (e1 == 0) return 0; /* 'e1' ensures that first can be used */
else if ((e1 | e2) & 2) /* one of the children has a matchtime? */
return 2; /* pattern has a matchtime capture */
else return e2; /* else depends on 'e2' */
}
}
case TRep: {
getfirst(sib1(tree), follow, firstset);
loopset(i, firstset->cs[i] |= follow->cs[i]);
return 1; /* accept the empty string */
}
case TCapture: case TGrammar: case TRule: {
/* return getfirst(sib1(tree), follow, firstset); */
tree = sib1(tree); goto tailcall;
}
case TRunTime: { /* function invalidates any follow info. */
int e = getfirst(sib1(tree), fullset, firstset);
if (e) return 2; /* function is not "protected"? */
else return 0; /* pattern inside capture ensures first can be used */
}
case TCall: {
/* return getfirst(sib2(tree), follow, firstset); */
tree = sib2(tree); goto tailcall;
}
case TAnd: {
int e = getfirst(sib1(tree), follow, firstset);
loopset(i, firstset->cs[i] &= follow->cs[i]);
return e;
}
case TNot: {
if (tocharset(sib1(tree), firstset)) {
cs_complement(firstset);
return 1;
}
/* else go through */
}
case TBehind: { /* instruction gives no new information */
/* call 'getfirst' to check for math-time captures */
int e = getfirst(sib1(tree), follow, firstset);
loopset(i, firstset->cs[i] = follow->cs[i]); /* uses follow */
return e | 1; /* always can accept the empty string */
}
default: assert(0); return 0;
}
}
/*
** If it returns true, then pattern can fail only depending on the next
** character of the subject
*/
static int headfail (TTree *tree) {
tailcall:
switch (tree->tag) {
case TChar: case TSet: case TAny: case TFalse:
return 1;
case TTrue: case TRep: case TRunTime: case TNot:
case TBehind:
return 0;
case TCapture: case TGrammar: case TRule: case TAnd:
tree = sib1(tree); goto tailcall; /* return headfail(sib1(tree)); */
case TCall:
tree = sib2(tree); goto tailcall; /* return headfail(sib2(tree)); */
case TSeq:
if (!nofail(sib2(tree))) return 0;
/* else return headfail(sib1(tree)); */
tree = sib1(tree); goto tailcall;
case TChoice:
if (!headfail(sib1(tree))) return 0;
/* else return headfail(sib2(tree)); */
tree = sib2(tree); goto tailcall;
default: assert(0); return 0;
}
}
/*
** Check whether the code generation for the given tree can benefit
** from a follow set (to avoid computing the follow set when it is
** not needed)
*/
static int needfollow (TTree *tree) {
tailcall:
switch (tree->tag) {
case TChar: case TSet: case TAny:
case TFalse: case TTrue: case TAnd: case TNot:
case TRunTime: case TGrammar: case TCall: case TBehind:
return 0;
case TChoice: case TRep:
return 1;
case TCapture:
tree = sib1(tree); goto tailcall;
case TSeq:
tree = sib2(tree); goto tailcall;
default: assert(0); return 0;
}
}
/* }====================================================== */
/*
** {======================================================
** Code generation
** =======================================================
*/
/*
** size of an instruction
*/
int sizei (const Instruction *i) {
switch((Opcode)i->i.code) {
case ISet: case ISpan: return CHARSETINSTSIZE;
case ITestSet: return CHARSETINSTSIZE + 1;
case ITestChar: case ITestAny: case IChoice: case IJmp:
case ICall: case IOpenCall: case ICommit: case IPartialCommit:
case IBackCommit: return 2;
default: return 1;
}
}
/*
** state for the compiler
*/
typedef struct CompileState {
Pattern *p; /* pattern being compiled */
int ncode; /* next position in p->code to be filled */
lua_State *L;
} CompileState;
/*
** code generation is recursive; 'opt' indicates that the code is
** being generated under a 'IChoice' operator jumping to its end.
** 'tt' points to a previous test protecting this code. 'fl' is
** the follow set of the pattern.
*/
static void codegen (CompileState *compst, TTree *tree, int opt, int tt,
const Charset *fl);
void reallocprog (lua_State *L, Pattern *p, int nsize) {
void *ud;
lua_Alloc f = lua_getallocf(L, &ud);
void *newblock = f(ud, p->code, p->codesize * sizeof(Instruction),
nsize * sizeof(Instruction));
if (newblock == NULL && nsize > 0)
luaL_error(L, "not enough memory");
p->code = (Instruction *)newblock;
p->codesize = nsize;
}
static int nextinstruction (CompileState *compst) {
int size = compst->p->codesize;
if (compst->ncode >= size)
reallocprog(compst->L, compst->p, size * 2);
return compst->ncode++;
}
#define getinstr(cs,i) ((cs)->p->code[i])
static int addinstruction (CompileState *compst, Opcode op, int aux) {
int i = nextinstruction(compst);
getinstr(compst, i).i.code = op;
getinstr(compst, i).i.aux = aux;
return i;
}
static int addoffsetinst (CompileState *compst, Opcode op) {
int i = addinstruction(compst, op, 0); /* instruction */
addinstruction(compst, (Opcode)0, 0); /* open space for offset */
assert(op == ITestSet || sizei(&getinstr(compst, i)) == 2);
return i;
}
static void setoffset (CompileState *compst, int instruction, int offset) {
getinstr(compst, instruction + 1).offset = offset;
}
/*
** Add a capture instruction:
** 'op' is the capture instruction; 'cap' the capture kind;
** 'key' the key into ktable; 'aux' is optional offset
**
*/
static int addinstcap (CompileState *compst, Opcode op, int cap, int key,
int aux) {
int i = addinstruction(compst, op, joinkindoff(cap, aux));
getinstr(compst, i).i.key = key;
return i;
}
#define gethere(compst) ((compst)->ncode)
#define target(code,i) ((i) + code[i + 1].offset)
static void jumptothere (CompileState *compst, int instruction, int target) {
if (instruction >= 0)
setoffset(compst, instruction, target - instruction);
}
static void jumptohere (CompileState *compst, int instruction) {
jumptothere(compst, instruction, gethere(compst));
}
/*
** Code an IChar instruction, or IAny if there is an equivalent
** test dominating it
*/
static void codechar (CompileState *compst, int c, int tt) {
if (tt >= 0 && getinstr(compst, tt).i.code == ITestChar &&
getinstr(compst, tt).i.aux == c)
addinstruction(compst, IAny, 0);
else
addinstruction(compst, IChar, c);
}
/*
** Add a charset posfix to an instruction
*/
static void addcharset (CompileState *compst, const byte *cs) {
int p = gethere(compst);
int i;
for (i = 0; i < (int)CHARSETINSTSIZE - 1; i++)
nextinstruction(compst); /* space for buffer */
/* fill buffer with charset */
loopset(j, getinstr(compst, p).buff[j] = cs[j]);
}
/*
** code a char set, optimizing unit sets for IChar, "complete"
** sets for IAny, and empty sets for IFail; also use an IAny
** when instruction is dominated by an equivalent test.
*/
static void codecharset (CompileState *compst, const byte *cs, int tt) {
int c = 0; /* (=) to avoid warnings */
Opcode op = charsettype(cs, &c);
switch (op) {
case IChar: codechar(compst, c, tt); break;
case ISet: { /* non-trivial set? */
if (tt >= 0 && getinstr(compst, tt).i.code == ITestSet &&
cs_equal(cs, getinstr(compst, tt + 2).buff))
addinstruction(compst, IAny, 0);
else {
addinstruction(compst, ISet, 0);
addcharset(compst, cs);
}
break;
}
default: addinstruction(compst, op, c); break;
}
}
/*
** code a test set, optimizing unit sets for ITestChar, "complete"
** sets for ITestAny, and empty sets for IJmp (always fails).
** 'e' is true iff test should accept the empty string. (Test
** instructions in the current VM never accept the empty string.)
*/
static int codetestset (CompileState *compst, Charset *cs, int e) {
if (e) return NOINST; /* no test */
else {
int c = 0;
Opcode op = charsettype(cs->cs, &c);
switch (op) {
case IFail: return addoffsetinst(compst, IJmp); /* always jump */
case IAny: return addoffsetinst(compst, ITestAny);
case IChar: {
int i = addoffsetinst(compst, ITestChar);
getinstr(compst, i).i.aux = c;
return i;
}
case ISet: {
int i = addoffsetinst(compst, ITestSet);
addcharset(compst, cs->cs);
return i;
}
default: assert(0); return 0;
}
}
}
/*
** Find the final destination of a sequence of jumps
*/
static int finaltarget (Instruction *code, int i) {
while (code[i].i.code == IJmp)
i = target(code, i);
return i;
}
/*
** final label (after traversing any jumps)
*/
static int finallabel (Instruction *code, int i) {
return finaltarget(code, target(code, i));
}
/*
** <behind(p)> == behind n; <p> (where n = fixedlen(p))
*/
static void codebehind (CompileState *compst, TTree *tree) {
if (tree->u.n > 0)
addinstruction(compst, IBehind, tree->u.n);
codegen(compst, sib1(tree), 0, NOINST, fullset);
}
/*
** Choice; optimizations:
** - when p1 is headfail
** - when first(p1) and first(p2) are disjoint; than
** a character not in first(p1) cannot go to p1, and a character
** in first(p1) cannot go to p2 (at it is not in first(p2)).
** (The optimization is not valid if p1 accepts the empty string,
** as then there is no character at all...)
** - when p2 is empty and opt is true; a IPartialCommit can resuse
** the Choice already active in the stack.
*/
static void codechoice (CompileState *compst, TTree *p1, TTree *p2, int opt,
const Charset *fl) {
int emptyp2 = (p2->tag == TTrue);
Charset cs1, cs2;
int e1 = getfirst(p1, fullset, &cs1);
if (headfail(p1) ||
(!e1 && (getfirst(p2, fl, &cs2), cs_disjoint(&cs1, &cs2)))) {
/* <p1 / p2> == test (fail(p1)) -> L1 ; p1 ; jmp L2; L1: p2; L2: */
int test = codetestset(compst, &cs1, 0);
int jmp = NOINST;
codegen(compst, p1, 0, test, fl);
if (!emptyp2)
jmp = addoffsetinst(compst, IJmp);
jumptohere(compst, test);
codegen(compst, p2, opt, NOINST, fl);
jumptohere(compst, jmp);
}
else if (opt && emptyp2) {
/* p1? == IPartialCommit; p1 */
jumptohere(compst, addoffsetinst(compst, IPartialCommit));
codegen(compst, p1, 1, NOINST, fullset);
}
else {
/* <p1 / p2> ==
test(fail(p1)) -> L1; choice L1; <p1>; commit L2; L1: <p2>; L2: */
int pcommit;
int test = codetestset(compst, &cs1, e1);
int pchoice = addoffsetinst(compst, IChoice);
codegen(compst, p1, emptyp2, test, fullset);
pcommit = addoffsetinst(compst, ICommit);
jumptohere(compst, pchoice);
jumptohere(compst, test);
codegen(compst, p2, opt, NOINST, fl);
jumptohere(compst, pcommit);
}
}
/*
** And predicate
** optimization: fixedlen(p) = n ==> <&p> == <p>; behind n
** (valid only when 'p' has no captures)
*/
static void codeand (CompileState *compst, TTree *tree, int tt) {
int n = fixedlen(tree);
if (n >= 0 && n <= MAXBEHIND && !hascaptures(tree)) {
codegen(compst, tree, 0, tt, fullset);
if (n > 0)
addinstruction(compst, IBehind, n);
}
else { /* default: Choice L1; p1; BackCommit L2; L1: Fail; L2: */
int pcommit;
int pchoice = addoffsetinst(compst, IChoice);
codegen(compst, tree, 0, tt, fullset);
pcommit = addoffsetinst(compst, IBackCommit);
jumptohere(compst, pchoice);
addinstruction(compst, IFail, 0);
jumptohere(compst, pcommit);
}
}
/*
** Captures: if pattern has fixed (and not too big) length, use
** a single IFullCapture instruction after the match; otherwise,
** enclose the pattern with OpenCapture - CloseCapture.
*/
static void codecapture (CompileState *compst, TTree *tree, int tt,
const Charset *fl) {
int len = fixedlen(sib1(tree));
if (len >= 0 && len <= MAXOFF && !hascaptures(sib1(tree))) {
codegen(compst, sib1(tree), 0, tt, fl);
addinstcap(compst, IFullCapture, tree->cap, tree->key, len);
}
else {
addinstcap(compst, IOpenCapture, tree->cap, tree->key, 0);
codegen(compst, sib1(tree), 0, tt, fl);
addinstcap(compst, ICloseCapture, Cclose, 0, 0);
}
}
static void coderuntime (CompileState *compst, TTree *tree, int tt) {
addinstcap(compst, IOpenCapture, Cgroup, tree->key, 0);
codegen(compst, sib1(tree), 0, tt, fullset);
addinstcap(compst, ICloseRunTime, Cclose, 0, 0);
}
/*
** Repetion; optimizations:
** When pattern is a charset, can use special instruction ISpan.
** When pattern is head fail, or if it starts with characters that
** are disjoint from what follows the repetions, a simple test
** is enough (a fail inside the repetition would backtrack to fail
** again in the following pattern, so there is no need for a choice).
** When 'opt' is true, the repetion can reuse the Choice already
** active in the stack.
*/
static void coderep (CompileState *compst, TTree *tree, int opt,
const Charset *fl) {
Charset st;
if (tocharset(tree, &st)) {
addinstruction(compst, ISpan, 0);
addcharset(compst, st.cs);
}
else {
int e1 = getfirst(tree, fullset, &st);
if (headfail(tree) || (!e1 && cs_disjoint(&st, fl))) {
/* L1: test (fail(p1)) -> L2; <p>; jmp L1; L2: */
int jmp;
int test = codetestset(compst, &st, 0);
codegen(compst, tree, opt, test, fullset);
jmp = addoffsetinst(compst, IJmp);
jumptohere(compst, test);
jumptothere(compst, jmp, test);
}
else {
/* test(fail(p1)) -> L2; choice L2; L1: <p>; partialcommit L1; L2: */
/* or (if 'opt'): partialcommit L1; L1: <p>; partialcommit L1; */
int commit, l2;
int test = codetestset(compst, &st, e1);
int pchoice = NOINST;
if (opt)
jumptohere(compst, addoffsetinst(compst, IPartialCommit));
else
pchoice = addoffsetinst(compst, IChoice);
l2 = gethere(compst);
codegen(compst, tree, 0, NOINST, fullset);
commit = addoffsetinst(compst, IPartialCommit);
jumptothere(compst, commit, l2);
jumptohere(compst, pchoice);
jumptohere(compst, test);
}
}
}
/*
** Not predicate; optimizations:
** In any case, if first test fails, 'not' succeeds, so it can jump to
** the end. If pattern is headfail, that is all (it cannot fail
** in other parts); this case includes 'not' of simple sets. Otherwise,
** use the default code (a choice plus a failtwice).
*/
static void codenot (CompileState *compst, TTree *tree) {
Charset st;
int e = getfirst(tree, fullset, &st);
int test = codetestset(compst, &st, e);
if (headfail(tree)) /* test (fail(p1)) -> L1; fail; L1: */
addinstruction(compst, IFail, 0);
else {
/* test(fail(p))-> L1; choice L1; <p>; failtwice; L1: */
int pchoice = addoffsetinst(compst, IChoice);
codegen(compst, tree, 0, NOINST, fullset);
addinstruction(compst, IFailTwice, 0);
jumptohere(compst, pchoice);
}
jumptohere(compst, test);
}
/*
** change open calls to calls, using list 'positions' to find
** correct offsets; also optimize tail calls
*/
static void correctcalls (CompileState *compst, int *positions,
int from, int to) {
int i;
Instruction *code = compst->p->code;
for (i = from; i < to; i += sizei(&code[i])) {
if (code[i].i.code == IOpenCall) {
int n = code[i].i.key; /* rule number */
int rule = positions[n]; /* rule position */
assert(rule == from || code[rule - 1].i.code == IRet);
if (code[finaltarget(code, i + 2)].i.code == IRet) /* call; ret ? */
code[i].i.code = IJmp; /* tail call */
else
code[i].i.code = ICall;
jumptothere(compst, i, rule); /* call jumps to respective rule */
}
}
assert(i == to);
}
/*
** Code for a grammar:
** call L1; jmp L2; L1: rule 1; ret; rule 2; ret; ...; L2:
*/
static void codegrammar (CompileState *compst, TTree *grammar) {
int positions[MAXRULES];
int rulenumber = 0;
TTree *rule;
int firstcall = addoffsetinst(compst, ICall); /* call initial rule */
int jumptoend = addoffsetinst(compst, IJmp); /* jump to the end */
int start = gethere(compst); /* here starts the initial rule */
jumptohere(compst, firstcall);
for (rule = sib1(grammar); rule->tag == TRule; rule = sib2(rule)) {
positions[rulenumber++] = gethere(compst); /* save rule position */
codegen(compst, sib1(rule), 0, NOINST, fullset); /* code rule */
addinstruction(compst, IRet, 0);
}
assert(rule->tag == TTrue);
jumptohere(compst, jumptoend);
correctcalls(compst, positions, start, gethere(compst));
}
static void codecall (CompileState *compst, TTree *call) {
int c = addoffsetinst(compst, IOpenCall); /* to be corrected later */
getinstr(compst, c).i.key = sib2(call)->cap; /* rule number */
assert(sib2(call)->tag == TRule);
}
/*
** Code first child of a sequence
** (second child is called in-place to allow tail call)
** Return 'tt' for second child
*/
static int codeseq1 (CompileState *compst, TTree *p1, TTree *p2,
int tt, const Charset *fl) {
if (needfollow(p1)) {
Charset fl1;
getfirst(p2, fl, &fl1); /* p1 follow is p2 first */
codegen(compst, p1, 0, tt, &fl1);
}
else /* use 'fullset' as follow */
codegen(compst, p1, 0, tt, fullset);
if (fixedlen(p1) != 0) /* can 'p1' consume anything? */
return NOINST; /* invalidate test */
else return tt; /* else 'tt' still protects sib2 */
}
/*
** Main code-generation function: dispatch to auxiliar functions
** according to kind of tree
*/
static void codegen (CompileState *compst, TTree *tree, int opt, int tt,
const Charset *fl) {
tailcall:
switch (tree->tag) {
case TChar: codechar(compst, tree->u.n, tt); break;
case TAny: addinstruction(compst, IAny, 0); break;
case TSet: codecharset(compst, treebuffer(tree), tt); break;
case TTrue: break;
case TFalse: addinstruction(compst, IFail, 0); break;
case TChoice: codechoice(compst, sib1(tree), sib2(tree), opt, fl); break;
case TRep: coderep(compst, sib1(tree), opt, fl); break;
case TBehind: codebehind(compst, tree); break;
case TNot: codenot(compst, sib1(tree)); break;
case TAnd: codeand(compst, sib1(tree), tt); break;
case TCapture: codecapture(compst, tree, tt, fl); break;
case TRunTime: coderuntime(compst, tree, tt); break;
case TGrammar: codegrammar(compst, tree); break;
case TCall: codecall(compst, tree); break;
case TSeq: {
tt = codeseq1(compst, sib1(tree), sib2(tree), tt, fl); /* code 'p1' */
/* codegen(compst, p2, opt, tt, fl); */
tree = sib2(tree); goto tailcall;
}
default: assert(0);
}
}
/*
** Optimize jumps and other jump-like instructions.
** * Update labels of instructions with labels to their final
** destinations (e.g., choice L1; ... L1: jmp L2: becomes
** choice L2)
** * Jumps to other instructions that do jumps become those
** instructions (e.g., jump to return becomes a return; jump
** to commit becomes a commit)
*/
static void peephole (CompileState *compst) {
Instruction *code = compst->p->code;
int i;
for (i = 0; i < compst->ncode; i += sizei(&code[i])) {
switch (code[i].i.code) {
case IChoice: case ICall: case ICommit: case IPartialCommit:
case IBackCommit: case ITestChar: case ITestSet:
case ITestAny: { /* instructions with labels */
jumptothere(compst, i, finallabel(code, i)); /* optimize label */
break;
}
case IJmp: {
int ft = finaltarget(code, i);
switch (code[ft].i.code) { /* jumping to what? */
case IRet: case IFail: case IFailTwice:
case IEnd: { /* instructions with unconditional implicit jumps */
code[i] = code[ft]; /* jump becomes that instruction */
code[i + 1].i.code = IAny; /* 'no-op' for target position */
break;
}
case ICommit: case IPartialCommit:
case IBackCommit: { /* inst. with unconditional explicit jumps */
int fft = finallabel(code, ft);
code[i] = code[ft]; /* jump becomes that instruction... */
jumptothere(compst, i, fft); /* but must correct its offset */
i--; /* reoptimize its label */
break;
}
default: {
jumptothere(compst, i, ft); /* optimize label */
break;
}
}
break;
}
default: break;
}
}
assert(code[i - 1].i.code == IEnd);
}
/*
** Compile a pattern
*/
Instruction *compile (lua_State *L, Pattern *p) {
CompileState compst;
compst.p = p; compst.ncode = 0; compst.L = L;
reallocprog(L, p, 2); /* minimum initial size */
codegen(&compst, p->tree, 0, NOINST, fullset);
addinstruction(&compst, IEnd, 0);
reallocprog(L, p, compst.ncode); /* set final size */
peephole(&compst);
return p->code;
}
/* }====================================================== */
/*
** $Id: lpprint.c,v 1.7 2013/04/12 16:29:49 roberto Exp $
** Copyright 2007, Lua.org & PUC-Rio (see 'lpeg.html' for license)
*/
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#if defined(LPEG_DEBUG)
/*
** {======================================================
** Printing patterns (for debugging)
** =======================================================
*/
void printcharset (const byte *st) {
int i;
printf("[");
for (i = 0; i <= UCHAR_MAX; i++) {
int first = i;
while (testchar(st, i) && i <= UCHAR_MAX) i++;
if (i - 1 == first) /* unary range? */
printf("(%02x)", first);
else if (i - 1 > first) /* non-empty range? */
printf("(%02x-%02x)", first, i - 1);
}
printf("]");
}
static void printcapkind (int kind) {
const char *const modes[] = {
"close", "position", "constant", "backref",
"argument", "simple", "table", "function",
"query", "string", "num", "substitution", "fold",
"runtime", "group"};
printf("%s", modes[kind]);
}
static void printjmp (const Instruction *op, const Instruction *p) {
printf("-> %d", (int)(p + (p + 1)->offset - op));
}
static void printinst (const Instruction *op, const Instruction *p) {
const char *const names[] = {
"any", "char", "set",
"testany", "testchar", "testset",
"span", "behind",
"ret", "end",
"choice", "jmp", "call", "open_call",
"commit", "partial_commit", "back_commit", "failtwice", "fail", "giveup",
"fullcapture", "opencapture", "closecapture", "closeruntime"
};
printf("%02ld: %s ", (long)(p - op), names[p->i.code]);
switch ((Opcode)p->i.code) {
case IChar: {
printf("'%c'", p->i.aux);
break;
}
case ITestChar: {
printf("'%c'", p->i.aux); printjmp(op, p);
break;
}
case IFullCapture: {
printcapkind(getkind(p));
printf(" (size = %d) (idx = %d)", getoff(p), p->i.key);
break;
}
case IOpenCapture: {
printcapkind(getkind(p));
printf(" (idx = %d)", p->i.key);
break;
}
case ISet: {
printcharset((p+1)->buff);
break;
}
case ITestSet: {
printcharset((p+2)->buff); printjmp(op, p);
break;
}
case ISpan: {
printcharset((p+1)->buff);
break;
}
case IOpenCall: {
printf("-> %d", (p + 1)->offset);
break;
}
case IBehind: {
printf("%d", p->i.aux);
break;
}
case IJmp: case ICall: case ICommit: case IChoice:
case IPartialCommit: case IBackCommit: case ITestAny: {
printjmp(op, p);
break;
}
default: break;
}
printf("\n");
}
void printpatt (Instruction *p, int n) {
Instruction *op = p;
while (p < op + n) {
printinst(op, p);
p += sizei(p);
}
}
#if defined(LPEG_DEBUG)
static void printcap (Capture *cap) {
printcapkind(cap->kind);
printf(" (idx: %d - size: %d) -> %p\n", cap->idx, cap->siz, cap->s);
}
void printcaplist (Capture *cap, Capture *limit) {
printf(">======\n");
for (; cap->s && (limit == NULL || cap < limit); cap++)
printcap(cap);
printf("=======\n");
}
#endif
/* }====================================================== */
/*
** {======================================================
** Printing trees (for debugging)
** =======================================================
*/
static const char *tagnames[] = {
"char", "set", "any",
"true", "false",
"rep",
"seq", "choice",
"not", "and",
"call", "opencall", "rule", "grammar",
"behind",
"capture", "run-time"
};
void printtree (TTree *tree, int ident) {
int i;
for (i = 0; i < ident; i++) printf(" ");
printf("%s", tagnames[tree->tag]);
switch (tree->tag) {
case TChar: {
int c = tree->u.n;
if (isprint(c))
printf(" '%c'\n", c);
else
printf(" (%02X)\n", c);
break;
}
case TSet: {
printcharset(treebuffer(tree));
printf("\n");
break;
}
case TOpenCall: case TCall: {
printf(" key: %d\n", tree->key);
break;
}
case TBehind: {
printf(" %d\n", tree->u.n);
printtree(sib1(tree), ident + 2);
break;
}
case TCapture: {
printf(" cap: %d key: %d n: %d\n", tree->cap, tree->key, tree->u.n);
printtree(sib1(tree), ident + 2);
break;
}
case TRule: {
printf(" n: %d key: %d\n", tree->cap, tree->key);
printtree(sib1(tree), ident + 2);
break; /* do not print next rule as a sibling */
}
case TGrammar: {
TTree *rule = sib1(tree);
printf(" %d\n", tree->u.n); /* number of rules */
for (i = 0; i < tree->u.n; i++) {
printtree(rule, ident + 2);
rule = sib2(rule);
}
assert(rule->tag == TTrue); /* sentinel */
break;
}
default: {
int sibs = numsiblings[tree->tag];
printf("\n");
if (sibs >= 1) {
printtree(sib1(tree), ident + 2);
if (sibs >= 2)
printtree(sib2(tree), ident + 2);
}
break;
}
}
}
void printktable (lua_State *L, int idx) {
int n, i;
lua_getfenv(L, idx);
if (lua_isnil(L, -1)) /* no ktable? */
return;
n = lua_objlen(L, -1);
printf("[");
for (i = 1; i <= n; i++) {
printf("%d = ", i);
lua_rawgeti(L, -1, i);
if (lua_isstring(L, -1))
printf("%s ", lua_tostring(L, -1));
else
printf("%s ", lua_typename(L, lua_type(L, -1)));
lua_pop(L, 1);
}
printf("]\n");
/* leave ktable at the stack */
}
/* }====================================================== */
#endif
/*
** $Id: lptree.c,v 1.10 2013/04/12 16:30:33 roberto Exp $
** Copyright 2013, Lua.org & PUC-Rio (see 'lpeg.html' for license)
*/
#include <ctype.h>
#include <limits.h>
#include <string.h>
#include "lua.h"
#include "lauxlib.h"
/* number of siblings for each tree */
const byte numsiblings[] = {
0, 0, 0, /* char, set, any */
0, 0, /* true, false */
1, /* rep */
2, 2, /* seq, choice */
1, 1, /* not, and */
0, 0, 2, 1, /* call, opencall, rule, grammar */
1, /* behind */
1, 1 /* capture, runtime capture */
};
static TTree *newgrammar (lua_State *L, int arg);
/*
** returns a reasonable name for value at index 'idx' on the stack
*/
static const char *val2str (lua_State *L, int idx) {
const char *k = lua_tostring(L, idx);
if (k != NULL)
return lua_pushfstring(L, "%s", k);
else
return lua_pushfstring(L, "(a %s)", luaL_typename(L, idx));
}
/*
** Fix a TOpenCall into a TCall node, using table 'postable' to
** translate a key to its rule address in the tree. Raises an
** error if key does not exist.
*/
static void fixonecall (lua_State *L, int postable, TTree *g, TTree *t) {
int n;
lua_rawgeti(L, -1, t->key); /* get rule's name */
lua_gettable(L, postable); /* query name in position table */
n = (int)lua_tonumber(L, -1); /* get (absolute) position */
lua_pop(L, 1); /* remove position */
if (n == 0) { /* no position? */
lua_rawgeti(L, -1, t->key); /* get rule's name again */
luaL_error(L, "rule '%s' undefined in given grammar", val2str(L, -1));
}
t->tag = TCall;
t->u.ps = n - (t - g); /* position relative to node */
assert(sib2(t)->tag == TRule);
sib2(t)->key = t->key;
}
/*
** Transform left associative constructions into right
** associative ones, for sequence and choice; that is:
** (t11 + t12) + t2 => t11 + (t12 + t2)
** (t11 * t12) * t2 => t11 * (t12 * t2)
** (that is, Op (Op t11 t12) t2 => Op t11 (Op t12 t2))
*/
static void correctassociativity (TTree *tree) {
TTree *t1 = sib1(tree);
assert(tree->tag == TChoice || tree->tag == TSeq);
while (t1->tag == tree->tag) {
int n1size = tree->u.ps - 1; /* t1 == Op t11 t12 */
int n11size = t1->u.ps - 1;
int n12size = n1size - n11size - 1;
memmove(sib1(tree), sib1(t1), n11size * sizeof(TTree)); /* move t11 */
tree->u.ps = n11size + 1;
sib2(tree)->tag = tree->tag;
sib2(tree)->u.ps = n12size + 1;
}
}
/*
** Make final adjustments in a tree. Fix open calls in tree 't',
** making them refer to their respective rules or raising appropriate
** errors (if not inside a grammar). Correct associativity of associative
** constructions (making them right associative). Assume that tree's
** ktable is at the top of the stack (for error messages).
*/
static void finalfix (lua_State *L, int postable, TTree *g, TTree *t) {
tailcall:
switch (t->tag) {
case TGrammar: /* subgrammars were already fixed */
return;
case TOpenCall: {
if (g != NULL) /* inside a grammar? */
fixonecall(L, postable, g, t);
else { /* open call outside grammar */
lua_rawgeti(L, -1, t->key);
luaL_error(L, "rule '%s' used outside a grammar", val2str(L, -1));
}
break;
}
case TSeq: case TChoice:
correctassociativity(t);
break;
}
switch (numsiblings[t->tag]) {
case 1: /* finalfix(L, postable, g, sib1(t)); */
t = sib1(t); goto tailcall;
case 2:
finalfix(L, postable, g, sib1(t));
t = sib2(t); goto tailcall; /* finalfix(L, postable, g, sib2(t)); */
default: assert(numsiblings[t->tag] == 0); break;
}
}
/*
** {======================================================
** Tree generation
** =======================================================
*/
/*
** In 5.2, could use 'luaL_testudata'...
*/
static int testpattern (lua_State *L, int idx) {
if (lua_touserdata(L, idx)) { /* value is a userdata? */
if (lua_getmetatable(L, idx)) { /* does it have a metatable? */
luaL_getmetatable(L, PATTERN_T);
if (lua_rawequal(L, -1, -2)) { /* does it have the correct mt? */
lua_pop(L, 2); /* remove both metatables */
return 1;
}
}
}
return 0;
}
static Pattern *getpattern (lua_State *L, int idx) {
return (Pattern *)luaL_checkudata(L, idx, PATTERN_T);
}
static int getsize (lua_State *L, int idx) {
return (lua_objlen(L, idx) - sizeof(Pattern)) / sizeof(TTree) + 1;
}
static TTree *gettree (lua_State *L, int idx, int *len) {
Pattern *p = getpattern(L, idx);
if (len)
*len = getsize(L, idx);
return p->tree;
}
/*
** create a pattern
*/
static TTree *newtree (lua_State *L, int len) {
size_t size = (len - 1) * sizeof(TTree) + sizeof(Pattern);
Pattern *p = (Pattern *)lua_newuserdata(L, size);
luaL_getmetatable(L, PATTERN_T);
lua_setmetatable(L, -2);
p->code = NULL; p->codesize = 0;
return p->tree;
}
static TTree *newleaf (lua_State *L, int tag) {
TTree *tree = newtree(L, 1);
tree->tag = tag;
return tree;
}
static TTree *newcharset (lua_State *L) {
TTree *tree = newtree(L, bytes2slots(CHARSETSIZE) + 1);
tree->tag = TSet;
loopset(i, treebuffer(tree)[i] = 0);
return tree;
}
/*
** add to tree a sequence where first sibling is 'sib' (with size
** 'sibsize'); returns position for second sibling
*/
static TTree *seqaux (TTree *tree, TTree *sib, int sibsize) {
tree->tag = TSeq; tree->u.ps = sibsize + 1;
memcpy(sib1(tree), sib, sibsize * sizeof(TTree));
return sib2(tree);
}
/*
** Add element 'idx' to 'ktable' of pattern at the top of the stack;
** create new 'ktable' if necessary. Return index of new element.
*/
static int addtoktable (lua_State *L, int idx) {
if (idx == 0 || lua_isnil(L, idx)) /* no actual value to insert? */
return 0;
else {
int n;
lua_getfenv(L, -1); /* get ktable from pattern */
n = lua_objlen(L, -1);
if (n == 0) { /* is it empty/non-existent? */
lua_pop(L, 1); /* remove it */
lua_createtable(L, 1, 0); /* create a fresh table */
}
lua_pushvalue(L, idx); /* element to be added */
lua_rawseti(L, -2, n + 1);
lua_setfenv(L, -2); /* set it as ktable for pattern */
return n + 1;
}
}
/*
** Build a sequence of 'n' nodes, each with tag 'tag' and 'u.n' got
** from the array 's' (or 0 if array is NULL). (TSeq is binary, so it
** must build a sequence of sequence of sequence...)
*/
static void fillseq (TTree *tree, int tag, int n, const char *s) {
int i;
for (i = 0; i < n - 1; i++) { /* initial n-1 copies of Seq tag; Seq ... */
tree->tag = TSeq; tree->u.ps = 2;
sib1(tree)->tag = tag;
sib1(tree)->u.n = s ? (byte)s[i] : 0;
tree = sib2(tree);
}
tree->tag = tag; /* last one does not need TSeq */
tree->u.n = s ? (byte)s[i] : 0;
}
/*
** Numbers as patterns:
** 0 == true (always match); n == TAny repeated 'n' times;
** -n == not (TAny repeated 'n' times)
*/
static TTree *numtree (lua_State *L, int n) {
if (n == 0)
return newleaf(L, TTrue);
else {
TTree *tree, *nd;
if (n > 0)
tree = nd = newtree(L, 2 * n - 1);
else { /* negative: code it as !(-n) */
n = -n;
tree = newtree(L, 2 * n);
tree->tag = TNot;
nd = sib1(tree);
}
fillseq(nd, TAny, n, NULL); /* sequence of 'n' any's */
return tree;
}
}
/*
** Convert value at index 'idx' to a pattern
*/
static TTree *getpatt (lua_State *L, int idx, int *len) {
TTree *tree;
switch (lua_type(L, idx)) {
case LUA_TSTRING: {
size_t slen;
const char *s = lua_tolstring(L, idx, &slen); /* get string */
if (slen == 0) /* empty? */
tree = newleaf(L, TTrue); /* always match */
else {
tree = newtree(L, 2 * (slen - 1) + 1);
fillseq(tree, TChar, slen, s); /* sequence of 'slen' chars */
}
break;
}
case LUA_TNUMBER: {
int n = lua_tointeger(L, idx);
tree = numtree(L, n);
break;
}
case LUA_TBOOLEAN: {
tree = (lua_toboolean(L, idx) ? newleaf(L, TTrue) : newleaf(L, TFalse));
break;
}
case LUA_TTABLE: {
tree = newgrammar(L, idx);
break;
}
case LUA_TFUNCTION: {
tree = newtree(L, 2);
tree->tag = TRunTime;
tree->key = addtoktable(L, idx);
sib1(tree)->tag = TTrue;
break;
}
default: {
return gettree(L, idx, len);
}
}
lua_replace(L, idx); /* put new tree into 'idx' slot */
if (len)
*len = getsize(L, idx);
return tree;
}
/*
** Return the number of elements in the ktable of pattern at 'idx'.
** In Lua 5.2, default "environment" for patterns is nil, not
** a table. Treat it as an empty table. In Lua 5.1, assumes that
** the environment has no numeric indices (len == 0)
*/
static int ktablelen (lua_State *L, int idx) {
if (!lua_istable(L, idx)) return 0;
else return lua_objlen(L, idx);
}
/*
** Concatentate the contents of table 'idx1' into table 'idx2'.
** (Assume that both indices are negative.)
** Return the original length of table 'idx2'
*/
static int concattable (lua_State *L, int idx1, int idx2) {
int i;
int n1 = ktablelen(L, idx1);
int n2 = ktablelen(L, idx2);
if (n1 == 0) return 0; /* nothing to correct */
for (i = 1; i <= n1; i++) {
lua_rawgeti(L, idx1, i);
lua_rawseti(L, idx2 - 1, n2 + i); /* correct 'idx2' */
}
return n2;
}
/*
** Make a merge of ktables from p1 and p2 the ktable for the new
** pattern at the top of the stack.
*/
static int joinktables (lua_State *L, int p1, int p2) {
int n1, n2;
lua_getfenv(L, p1); /* get ktables */
lua_getfenv(L, p2);
n1 = ktablelen(L, -2);
n2 = ktablelen(L, -1);
if (n1 == 0 && n2 == 0) { /* are both tables empty? */
lua_pop(L, 2); /* nothing to be done; pop tables */
return 0; /* nothing to correct */
}
if (n2 == 0 || lua_equal(L, -2, -1)) { /* second table is empty or equal? */
lua_pop(L, 1); /* pop 2nd table */
lua_setfenv(L, -2); /* set 1st ktable into new pattern */
return 0; /* nothing to correct */
}
if (n1 == 0) { /* first table is empty? */
lua_setfenv(L, -3); /* set 2nd table into new pattern */
lua_pop(L, 1); /* pop 1st table */
return 0; /* nothing to correct */
}
else {
lua_createtable(L, n1 + n2, 0); /* create ktable for new pattern */
/* stack: new p; ktable p1; ktable p2; new ktable */
concattable(L, -3, -1); /* from p1 into new ktable */
concattable(L, -2, -1); /* from p2 into new ktable */
lua_setfenv(L, -4); /* new ktable becomes p env */
lua_pop(L, 2); /* pop other ktables */
return n1; /* correction for indices from p2 */
}
}
static void correctkeys (TTree *tree, int n) {
if (n == 0) return; /* no correction? */
tailcall:
switch (tree->tag) {
case TOpenCall: case TCall: case TRunTime: case TRule: {
if (tree->key > 0)
tree->key += n;
break;
}
case TCapture: {
if (tree->key > 0 && tree->cap != Carg && tree->cap != Cnum)
tree->key += n;
break;
}
default: break;
}
switch (numsiblings[tree->tag]) {
case 1: /* correctkeys(sib1(tree), n); */
tree = sib1(tree); goto tailcall;
case 2:
correctkeys(sib1(tree), n);
tree = sib2(tree); goto tailcall; /* correctkeys(sib2(tree), n); */
default: assert(numsiblings[tree->tag] == 0); break;
}
}
/*
** copy 'ktable' of element 'idx' to new tree (on top of stack)
*/
static void copyktable (lua_State *L, int idx) {
lua_getfenv(L, idx);
lua_setfenv(L, -2);
}
/*
** merge 'ktable' from rule at stack index 'idx' into 'ktable'
** from tree at the top of the stack, and correct corresponding
** tree.
*/
static void mergektable (lua_State *L, int idx, TTree *rule) {
int n;
lua_getfenv(L, -1); /* get ktables */
lua_getfenv(L, idx);
n = concattable(L, -1, -2);
lua_pop(L, 2); /* remove both ktables */
correctkeys(rule, n);
}
/*
** create a new tree, whith a new root and one sibling.
** Sibling must be on the Lua stack, at index 1.
*/
static TTree *newroot1sib (lua_State *L, int tag) {
int s1;
TTree *tree1 = getpatt(L, 1, &s1);
TTree *tree = newtree(L, 1 + s1); /* create new tree */
tree->tag = tag;
memcpy(sib1(tree), tree1, s1 * sizeof(TTree));
copyktable(L, 1);
return tree;
}
/*
** create a new tree, whith a new root and 2 siblings.
** Siblings must be on the Lua stack, first one at index 1.
*/
static TTree *newroot2sib (lua_State *L, int tag) {
int s1, s2;
TTree *tree1 = getpatt(L, 1, &s1);
TTree *tree2 = getpatt(L, 2, &s2);
TTree *tree = newtree(L, 1 + s1 + s2); /* create new tree */
tree->tag = tag;
tree->u.ps = 1 + s1;
memcpy(sib1(tree), tree1, s1 * sizeof(TTree));
memcpy(sib2(tree), tree2, s2 * sizeof(TTree));
correctkeys(sib2(tree), joinktables(L, 1, 2));
return tree;
}
static int lp_P (lua_State *L) {
luaL_checkany(L, 1);
getpatt(L, 1, NULL);
lua_settop(L, 1);
return 1;
}
/*
** sequence operator; optimizations:
** false x => false, x true => x, true x => x
** (cannot do x . false => false because x may have runtime captures)
*/
static int lp_seq (lua_State *L) {
TTree *tree1 = getpatt(L, 1, NULL);
TTree *tree2 = getpatt(L, 2, NULL);
if (tree1->tag == TFalse || tree2->tag == TTrue)
lua_pushvalue(L, 1); /* false . x == false, x . true = x */
else if (tree1->tag == TTrue)
lua_pushvalue(L, 2); /* true . x = x */
else
newroot2sib(L, TSeq);
return 1;
}
/*
** choice operator; optimizations:
** charset / charset => charset
** true / x => true, x / false => x, false / x => x
** (x / true is not equivalent to true)
*/
static int lp_choice (lua_State *L) {
Charset st1, st2;
TTree *t1 = getpatt(L, 1, NULL);
TTree *t2 = getpatt(L, 2, NULL);
if (tocharset(t1, &st1) && tocharset(t2, &st2)) {
TTree *t = newcharset(L);
loopset(i, treebuffer(t)[i] = st1.cs[i] | st2.cs[i]);
}
else if (nofail(t1) || t2->tag == TFalse)
lua_pushvalue(L, 1); /* true / x => true, x / false => x */
else if (t1->tag == TFalse)
lua_pushvalue(L, 2); /* false / x => x */
else
newroot2sib(L, TChoice);
return 1;
}
/*
** p^n
*/
static int lp_star (lua_State *L) {
int size1;
int n = luaL_checkint(L, 2);
TTree *tree1 = gettree(L, 1, &size1);
if (n >= 0) { /* seq tree1 (seq tree1 ... (seq tree1 (rep tree1))) */
TTree *tree = newtree(L, (n + 1) * (size1 + 1));
if (nullable(tree1))
luaL_error(L, "loop body may accept empty string");
while (n--) /* repeat 'n' times */
tree = seqaux(tree, tree1, size1);
tree->tag = TRep;
memcpy(sib1(tree), tree1, size1 * sizeof(TTree));
}
else { /* choice (seq tree1 ... choice tree1 true ...) true */
TTree *tree;
n = -n;
/* size = (choice + seq + tree1 + true) * n, but the last has no seq */
tree = newtree(L, n * (size1 + 3) - 1);
for (; n > 1; n--) { /* repeat (n - 1) times */
tree->tag = TChoice; tree->u.ps = n * (size1 + 3) - 2;
sib2(tree)->tag = TTrue;
tree = sib1(tree);
tree = seqaux(tree, tree1, size1);
}
tree->tag = TChoice; tree->u.ps = size1 + 1;
sib2(tree)->tag = TTrue;
memcpy(sib1(tree), tree1, size1 * sizeof(TTree));
}
copyktable(L, 1);
return 1;
}
/*
** #p == &p
*/
static int lp_and (lua_State *L) {
newroot1sib(L, TAnd);
return 1;
}
/*
** -p == !p
*/
static int lp_not (lua_State *L) {
newroot1sib(L, TNot);
return 1;
}
/*
** [t1 - t2] == Seq (Not t2) t1
** If t1 and t2 are charsets, make their difference.
*/
static int lp_sub (lua_State *L) {
Charset st1, st2;
int s1, s2;
TTree *t1 = getpatt(L, 1, &s1);
TTree *t2 = getpatt(L, 2, &s2);
if (tocharset(t1, &st1) && tocharset(t2, &st2)) {
TTree *t = newcharset(L);
loopset(i, treebuffer(t)[i] = st1.cs[i] & ~st2.cs[i]);
}
else {
TTree *tree = newtree(L, 2 + s1 + s2);
tree->tag = TSeq; /* sequence of... */
tree->u.ps = 2 + s2;
sib1(tree)->tag = TNot; /* ...not... */
memcpy(sib1(sib1(tree)), t2, s2 * sizeof(TTree)); /* ...t2 */
memcpy(sib2(tree), t1, s1 * sizeof(TTree)); /* ... and t1 */
correctkeys(sib1(tree), joinktables(L, 1, 2));
}
return 1;
}
static int lp_set (lua_State *L) {
size_t l;
const char *s = luaL_checklstring(L, 1, &l);
TTree *tree = newcharset(L);
while (l--) {
setchar(treebuffer(tree), (byte)(*s));
s++;
}
return 1;
}
static int lp_range (lua_State *L) {
int arg;
int top = lua_gettop(L);
TTree *tree = newcharset(L);
for (arg = 1; arg <= top; arg++) {
int c;
size_t l;
const char *r = luaL_checklstring(L, arg, &l);
luaL_argcheck(L, l == 2, arg, "range must have two characters");
for (c = (byte)r[0]; c <= (byte)r[1]; c++)
setchar(treebuffer(tree), c);
}
return 1;
}
/*
** Look-behind predicate
*/
static int lp_behind (lua_State *L) {
TTree *tree;
TTree *tree1 = getpatt(L, 1, NULL);
int n = fixedlen(tree1);
luaL_argcheck(L, !hascaptures(tree1), 1, "pattern have captures");
luaL_argcheck(L, n > 0, 1, "pattern may not have fixed length");
luaL_argcheck(L, n <= MAXBEHIND, 1, "pattern too long to look behind");
tree = newroot1sib(L, TBehind);
tree->u.n = n;
return 1;
}
/*
** Create a non-terminal
*/
static int lp_V (lua_State *L) {
TTree *tree = newleaf(L, TOpenCall);
luaL_argcheck(L, !lua_isnoneornil(L, 1), 1, "non-nil value expected");
tree->key = addtoktable(L, 1);
return 1;
}
/*
** Create a tree for a non-empty capture, with a body and
** optionally with an associated Lua value (at index 'labelidx' in the
** stack)
*/
static int capture_aux (lua_State *L, int cap, int labelidx) {
TTree *tree = newroot1sib(L, TCapture);
tree->cap = cap;
tree->key = addtoktable(L, labelidx);
return 1;
}
/*
** Fill a tree with an empty capture, using an empty (TTrue) sibling.
*/
static TTree *auxemptycap (lua_State *L, TTree *tree, int cap, int idx) {
tree->tag = TCapture;
tree->cap = cap;
tree->key = addtoktable(L, idx);
sib1(tree)->tag = TTrue;
return tree;
}
/*
** Create a tree for an empty capture
*/
static TTree *newemptycap (lua_State *L, int cap, int idx) {
return auxemptycap(L, newtree(L, 2), cap, idx);
}
/*
** Captures with syntax p / v
** (function capture, query capture, string capture, or number capture)
*/
static int lp_divcapture (lua_State *L) {
switch (lua_type(L, 2)) {
case LUA_TFUNCTION: return capture_aux(L, Cfunction, 2);
case LUA_TTABLE: return capture_aux(L, Cquery, 2);
case LUA_TSTRING: return capture_aux(L, Cstring, 2);
case LUA_TNUMBER: {
int n = lua_tointeger(L, 2);
TTree *tree = newroot1sib(L, TCapture);
luaL_argcheck(L, 0 <= n && n <= SHRT_MAX, 1, "invalid number");
tree->cap = Cnum;
tree->key = n;
return 1;
}
default: return luaL_argerror(L, 2, "invalid replacement value");
}
}
static int lp_substcapture (lua_State *L) {
return capture_aux(L, Csubst, 0);
}
static int lp_tablecapture (lua_State *L) {
return capture_aux(L, Ctable, 0);
}
static int lp_groupcapture (lua_State *L) {
if (lua_isnoneornil(L, 2))
return capture_aux(L, Cgroup, 0);
else {
luaL_checkstring(L, 2);
return capture_aux(L, Cgroup, 2);
}
}
static int lp_foldcapture (lua_State *L) {
luaL_checktype(L, 2, LUA_TFUNCTION);
return capture_aux(L, Cfold, 2);
}
static int lp_simplecapture (lua_State *L) {
return capture_aux(L, Csimple, 0);
}
static int lp_poscapture (lua_State *L) {
newemptycap(L, Cposition, 0);
return 1;
}
static int lp_argcapture (lua_State *L) {
int n = luaL_checkint(L, 1);
TTree *tree = newemptycap(L, Carg, 0);
tree->key = n;
luaL_argcheck(L, 0 < n && n <= SHRT_MAX, 1, "invalid argument index");
return 1;
}
static int lp_backref (lua_State *L) {
luaL_checkstring(L, 1);
newemptycap(L, Cbackref, 1);
return 1;
}
/*
** Constant capture
*/
static int lp_constcapture (lua_State *L) {
int i;
int n = lua_gettop(L); /* number of values */
if (n == 0) /* no values? */
newleaf(L, TTrue); /* no capture */
else if (n == 1)
newemptycap(L, Cconst, 1); /* single constant capture */
else { /* create a group capture with all values */
TTree *tree = newtree(L, 1 + 3 * (n - 1) + 2);
tree->tag = TCapture;
tree->cap = Cgroup;
tree->key = 0;
tree = sib1(tree);
for (i = 1; i <= n - 1; i++) {
tree->tag = TSeq;
tree->u.ps = 3; /* skip TCapture and its sibling */
auxemptycap(L, sib1(tree), Cconst, i);
tree = sib2(tree);
}
auxemptycap(L, tree, Cconst, i);
}
return 1;
}
static int lp_matchtime (lua_State *L) {
TTree *tree;
luaL_checktype(L, 2, LUA_TFUNCTION);
tree = newroot1sib(L, TRunTime);
tree->key = addtoktable(L, 2);
return 1;
}
/* }====================================================== */
/*
** {======================================================
** Grammar - Tree generation
** =======================================================
*/
/*
** push on the stack the index and the pattern for the
** initial rule of grammar at index 'arg' in the stack;
** also add that index into position table.
*/
static void getfirstrule (lua_State *L, int arg, int postab) {
lua_rawgeti(L, arg, 1); /* access first element */
if (lua_isstring(L, -1)) { /* is it the name of initial rule? */
lua_pushvalue(L, -1); /* duplicate it to use as key */
lua_gettable(L, arg); /* get associated rule */
}
else {
lua_pushinteger(L, 1); /* key for initial rule */
lua_insert(L, -2); /* put it before rule */
}
if (!testpattern(L, -1)) { /* initial rule not a pattern? */
if (lua_isnil(L, -1))
luaL_error(L, "grammar has no initial rule");
else
luaL_error(L, "initial rule '%s' is not a pattern", lua_tostring(L, -2));
}
lua_pushvalue(L, -2); /* push key */
lua_pushinteger(L, 1); /* push rule position (after TGrammar) */
lua_settable(L, postab); /* insert pair at position table */
}
/*
** traverse grammar at index 'arg', pushing all its keys and patterns
** into the stack. Create a new table (before all pairs key-pattern) to
** collect all keys and their associated positions in the final tree
** (the "position table").
** Return the number of rules and (in 'totalsize') the total size
** for the new tree.
*/
static int collectrules (lua_State *L, int arg, int *totalsize) {
int n = 1; /* to count number of rules */
int postab = lua_gettop(L) + 1; /* index of position table */
int size; /* accumulator for total size */
lua_newtable(L); /* create position table */
getfirstrule(L, arg, postab);
size = 2 + getsize(L, postab + 2); /* TGrammar + TRule + rule */
lua_pushnil(L); /* prepare to traverse grammar table */
while (lua_next(L, arg) != 0) {
if (lua_tonumber(L, -2) == 1 ||
lua_equal(L, -2, postab + 1)) { /* initial rule? */
lua_pop(L, 1); /* remove value (keep key for lua_next) */
continue;
}
if (!testpattern(L, -1)) /* value is not a pattern? */
luaL_error(L, "rule '%s' is not a pattern", val2str(L, -2));
luaL_checkstack(L, LUA_MINSTACK, "grammar has too many rules");
lua_pushvalue(L, -2); /* push key (to insert into position table) */
lua_pushinteger(L, size);
lua_settable(L, postab);
size += 1 + getsize(L, -1); /* update size */
lua_pushvalue(L, -2); /* push key (for next lua_next) */
n++;
}
*totalsize = size + 1; /* TTrue to finish list of rules */
return n;
}
static void buildgrammar (lua_State *L, TTree *grammar, int frule, int n) {
int i;
TTree *nd = sib1(grammar); /* auxiliary pointer to traverse the tree */
for (i = 0; i < n; i++) { /* add each rule into new tree */
int ridx = frule + 2*i + 1; /* index of i-th rule */
int rulesize;
TTree *rn = gettree(L, ridx, &rulesize);
nd->tag = TRule;
nd->key = 0;
nd->cap = i; /* rule number */
nd->u.ps = rulesize + 1; /* point to next rule */
memcpy(sib1(nd), rn, rulesize * sizeof(TTree)); /* copy rule */
mergektable(L, ridx, sib1(nd)); /* merge its ktable into new one */
nd = sib2(nd); /* move to next rule */
}
nd->tag = TTrue; /* finish list of rules */
}
/*
** Check whether a tree has potential infinite loops
*/
static int checkloops (TTree *tree) {
tailcall:
if (tree->tag == TRep && nullable(sib1(tree)))
return 1;
else if (tree->tag == TGrammar)
return 0; /* sub-grammars already checked */
else {
switch (numsiblings[tree->tag]) {
case 1: /* return checkloops(sib1(tree)); */
tree = sib1(tree); goto tailcall;
case 2:
if (checkloops(sib1(tree))) return 1;
/* else return checkloops(sib2(tree)); */
tree = sib2(tree); goto tailcall;
default: assert(numsiblings[tree->tag] == 0); return 0;
}
}
}
static int verifyerror (lua_State *L, int *passed, int npassed) {
int i, j;
for (i = npassed - 1; i >= 0; i--) { /* search for a repetition */
for (j = i - 1; j >= 0; j--) {
if (passed[i] == passed[j]) {
lua_rawgeti(L, -1, passed[i]); /* get rule's key */
return luaL_error(L, "rule '%s' may be left recursive", val2str(L, -1));
}
}
}
return luaL_error(L, "too many left calls in grammar");
}
/*
** Check whether a rule can be left recursive; raise an error in that
** case; otherwise return 1 iff pattern is nullable. Assume ktable at
** the top of the stack.
*/
static int verifyrule (lua_State *L, TTree *tree, int *passed, int npassed,
int nullable) {
tailcall:
switch (tree->tag) {
case TChar: case TSet: case TAny:
case TFalse:
return nullable; /* cannot pass from here */
case TTrue:
case TBehind: /* look-behind cannot have calls */
return 1;
case TNot: case TAnd: case TRep:
/* return verifyrule(L, sib1(tree), passed, npassed, 1); */
tree = sib1(tree); nullable = 1; goto tailcall;
case TCapture: case TRunTime:
/* return verifyrule(L, sib1(tree), passed, npassed); */
tree = sib1(tree); goto tailcall;
case TCall:
/* return verifyrule(L, sib2(tree), passed, npassed); */
tree = sib2(tree); goto tailcall;
case TSeq: /* only check 2nd child if first is nullable */
if (!verifyrule(L, sib1(tree), passed, npassed, 0))
return nullable;
/* else return verifyrule(L, sib2(tree), passed, npassed); */
tree = sib2(tree); goto tailcall;
case TChoice: /* must check both children */
nullable = verifyrule(L, sib1(tree), passed, npassed, nullable);
/* return verifyrule(L, sib2(tree), passed, npassed, nullable); */
tree = sib2(tree); goto tailcall;
case TRule:
if (npassed >= MAXRULES)
return verifyerror(L, passed, npassed);
else {
passed[npassed++] = tree->key;
/* return verifyrule(L, sib1(tree), passed, npassed); */
tree = sib1(tree); goto tailcall;
}
case TGrammar:
return nullable(tree); /* sub-grammar cannot be left recursive */
default: assert(0); return 0;
}
}
static void verifygrammar (lua_State *L, TTree *grammar) {
int passed[MAXRULES];
TTree *rule;
/* check left-recursive rules */
for (rule = sib1(grammar); rule->tag == TRule; rule = sib2(rule)) {
if (rule->key == 0) continue; /* unused rule */
verifyrule(L, sib1(rule), passed, 0, 0);
}
assert(rule->tag == TTrue);
/* check infinite loops inside rules */
for (rule = sib1(grammar); rule->tag == TRule; rule = sib2(rule)) {
if (rule->key == 0) continue; /* unused rule */
if (checkloops(sib1(rule))) {
lua_rawgeti(L, -1, rule->key); /* get rule's key */
luaL_error(L, "empty loop in rule '%s'", val2str(L, -1));
}
}
assert(rule->tag == TTrue);
}
/*
** Give a name for the initial rule if it is not referenced
*/
static void initialrulename (lua_State *L, TTree *grammar, int frule) {
if (sib1(grammar)->key == 0) { /* initial rule is not referenced? */
int n = lua_objlen(L, -1) + 1; /* index for name */
lua_pushvalue(L, frule); /* rule's name */
lua_rawseti(L, -2, n); /* ktable was on the top of the stack */
sib1(grammar)->key = n;
}
}
static TTree *newgrammar (lua_State *L, int arg) {
int treesize;
int frule = lua_gettop(L) + 2; /* position of first rule's key */
int n = collectrules(L, arg, &treesize);
TTree *g = newtree(L, treesize);
luaL_argcheck(L, n <= MAXRULES, arg, "grammar has too many rules");
g->tag = TGrammar; g->u.n = n;
lua_newtable(L); /* create 'ktable' */
lua_setfenv(L, -2);
buildgrammar(L, g, frule, n);
lua_getfenv(L, -1); /* get 'ktable' for new tree */
finalfix(L, frule - 1, g, sib1(g));
initialrulename(L, g, frule);
verifygrammar(L, g);
lua_pop(L, 1); /* remove 'ktable' */
lua_insert(L, -(n * 2 + 2)); /* move new table to proper position */
lua_pop(L, n * 2 + 1); /* remove position table + rule pairs */
return g; /* new table at the top of the stack */
}
/* }====================================================== */
static Instruction *prepcompile (lua_State *L, Pattern *p, int idx) {
lua_getfenv(L, idx); /* push 'ktable' (may be used by 'finalfix') */
finalfix(L, 0, NULL, p->tree);
lua_pop(L, 1); /* remove 'ktable' */
return compile(L, p);
}
static int lp_printtree (lua_State *L) {
TTree *tree = getpatt(L, 1, NULL);
int c = lua_toboolean(L, 2);
if (c) {
lua_getfenv(L, 1); /* push 'ktable' (may be used by 'finalfix') */
finalfix(L, 0, NULL, tree);
lua_pop(L, 1); /* remove 'ktable' */
}
printktable(L, 1);
printtree(tree, 0);
return 0;
}
static int lp_printcode (lua_State *L) {
Pattern *p = getpattern(L, 1);
printktable(L, 1);
if (p->code == NULL) /* not compiled yet? */
prepcompile(L, p, 1);
printpatt(p->code, p->codesize);
return 0;
}
/*
** Get the initial position for the match, interpreting negative
** values from the end of the subject
*/
static size_t initposition (lua_State *L, size_t len) {
lua_Integer ii = luaL_optinteger(L, 3, 1);
if (ii > 0) { /* positive index? */
if ((size_t)ii <= len) /* inside the string? */
return (size_t)ii - 1; /* return it (corrected to 0-base) */
else return len; /* crop at the end */
}
else { /* negative index */
if ((size_t)(-ii) <= len) /* inside the string? */
return len - ((size_t)(-ii)); /* return position from the end */
else return 0; /* crop at the beginning */
}
}
/*
** Main match function
*/
static int lp_match (lua_State *L) {
Capture capture[INITCAPSIZE];
const char *r;
size_t l;
Pattern *p = (getpatt(L, 1, NULL), getpattern(L, 1));
Instruction *code = (p->code != NULL) ? p->code : prepcompile(L, p, 1);
const char *s = luaL_checklstring(L, SUBJIDX, &l);
size_t i = initposition(L, l);
int ptop = lua_gettop(L);
lua_pushnil(L); /* initialize subscache */
lua_pushlightuserdata(L, capture); /* initialize caplistidx */
lua_getfenv(L, 1); /* initialize penvidx */
r = match(L, s, s + i, s + l, code, capture, ptop);
if (r == NULL) {
lua_pushnil(L);
return 1;
}
return getcaptures(L, s, r, ptop);
}
/*
** {======================================================
** Library creation and functions not related to matching
** =======================================================
*/
static int lp_setmax (lua_State *L) {
luaL_optinteger(L, 1, -1);
lua_settop(L, 1);
lua_setfield(L, LUA_REGISTRYINDEX, MAXSTACKIDX);
return 0;
}
static int lp_version (lua_State *L) {
lua_pushstring(L, VERSION);
return 1;
}
static int lp_type (lua_State *L) {
if (testpattern(L, 1))
lua_pushliteral(L, "pattern");
else
lua_pushnil(L);
return 1;
}
int lp_gc (lua_State *L) {
Pattern *p = getpattern(L, 1);
if (p->codesize > 0)
reallocprog(L, p, 0);
return 0;
}
static void createcat (lua_State *L, const char *catname, int (catf) (int)) {
TTree *t = newcharset(L);
int i;
for (i = 0; i <= UCHAR_MAX; i++)
if (catf(i)) setchar(treebuffer(t), i);
lua_setfield(L, -2, catname);
}
static int lp_locale (lua_State *L) {
if (lua_isnoneornil(L, 1)) {
lua_settop(L, 0);
lua_createtable(L, 0, 12);
}
else {
luaL_checktype(L, 1, LUA_TTABLE);
lua_settop(L, 1);
}
createcat(L, "alnum", isalnum);
createcat(L, "alpha", isalpha);
createcat(L, "cntrl", iscntrl);
createcat(L, "digit", isdigit);
createcat(L, "graph", isgraph);
createcat(L, "lower", islower);
createcat(L, "print", isprint);
createcat(L, "punct", ispunct);
createcat(L, "space", isspace);
createcat(L, "upper", isupper);
createcat(L, "xdigit", isxdigit);
return 1;
}
static struct luaL_Reg pattreg[] = {
{"ptree", lp_printtree},
{"pcode", lp_printcode},
{"match", lp_match},
{"B", lp_behind},
{"V", lp_V},
{"C", lp_simplecapture},
{"Cc", lp_constcapture},
{"Cmt", lp_matchtime},
{"Cb", lp_backref},
{"Carg", lp_argcapture},
{"Cp", lp_poscapture},
{"Cs", lp_substcapture},
{"Ct", lp_tablecapture},
{"Cf", lp_foldcapture},
{"Cg", lp_groupcapture},
{"P", lp_P},
{"S", lp_set},
{"R", lp_range},
{"locale", lp_locale},
{"version", lp_version},
{"setmaxstack", lp_setmax},
{"type", lp_type},
{NULL, NULL}
};
static struct luaL_Reg metareg[] = {
{"__mul", lp_seq},
{"__add", lp_choice},
{"__pow", lp_star},
{"__gc", lp_gc},
{"__len", lp_and},
{"__div", lp_divcapture},
{"__unm", lp_not},
{"__sub", lp_sub},
{NULL, NULL}
};
LUALIB_API int luaopen_lpeg (lua_State *L);
LUALIB_API int luaopen_lpeg (lua_State *L) {
luaL_newmetatable(L, PATTERN_T);
lua_pushnumber(L, MAXBACK); /* initialize maximum backtracking */
lua_setfield(L, LUA_REGISTRYINDEX, MAXSTACKIDX);
luaL_register(L, NULL, metareg);
luaL_register(L, "lpeg", pattreg);
lua_pushvalue(L, -1);
lua_setfield(L, -3, "__index");
return 1;
}
/* }====================================================== */
/*
** $Id: lpvm.c,v 1.5 2013/04/12 16:29:49 roberto Exp $
** Copyright 2007, Lua.org & PUC-Rio (see 'lpeg.html' for license)
*/
#include <limits.h>
#include <string.h>
#include "lua.h"
#include "lauxlib.h"
/* initial size for call/backtrack stack */
#if !defined(INITBACK)
#define INITBACK 100
#endif
#define getoffset(p) (((p) + 1)->offset)
static const Instruction giveup = {{IGiveup, 0, 0}};
/*
** {======================================================
** Virtual Machine
** =======================================================
*/
typedef struct Stack {
const char *s; /* saved position (or NULL for calls) */
const Instruction *p; /* next instruction */
int caplevel;
} Stack;
#define getstackbase(L, ptop) ((Stack *)lua_touserdata(L, stackidx(ptop)))
/*
** Double the size of the array of captures
*/
static Capture *doublecap (lua_State *L, Capture *cap, int captop, int ptop) {
Capture *newc;
if (captop >= INT_MAX/((int)sizeof(Capture) * 2))
luaL_error(L, "too many captures");
newc = (Capture *)lua_newuserdata(L, captop * 2 * sizeof(Capture));
memcpy(newc, cap, captop * sizeof(Capture));
lua_replace(L, caplistidx(ptop));
return newc;
}
/*
** Double the size of the stack
*/
static Stack *doublestack (lua_State *L, Stack **stacklimit, int ptop) {
Stack *stack = getstackbase(L, ptop);
Stack *newstack;
int n = *stacklimit - stack; /* current stack size */
int max, newn;
lua_getfield(L, LUA_REGISTRYINDEX, MAXSTACKIDX);
max = lua_tointeger(L, -1); /* maximum allowed size */
lua_pop(L, 1);
if (n >= max) /* already at maximum size? */
luaL_error(L, "too many pending calls/choices");
newn = 2 * n; /* new size */
if (newn > max) newn = max;
newstack = (Stack *)lua_newuserdata(L, newn * sizeof(Stack));
memcpy(newstack, stack, n * sizeof(Stack));
lua_replace(L, stackidx(ptop));
*stacklimit = newstack + newn;
return newstack + n; /* return next position */
}
/*
** Interpret the result of a dynamic capture: false -> fail;
** true -> keep current position; number -> next position.
** Return new subject position. 'fr' is stack index where
** is the result; 'curr' is current subject position; 'limit'
** is subject's size.
*/
static int resdyncaptures (lua_State *L, int fr, int curr, int limit) {
lua_Integer res;
if (!lua_toboolean(L, fr)) { /* false value? */
lua_settop(L, fr - 1); /* remove results */
return -1; /* and fail */
}
else if (lua_isboolean(L, fr)) /* true? */
res = curr; /* keep current position */
else {
res = lua_tointeger(L, fr) - 1; /* new position */
if (res < curr || res > limit)
luaL_error(L, "invalid position returned by match-time capture");
}
lua_remove(L, fr); /* remove first result (offset) */
return res;
}
/*
** Add capture values returned by a dynamic capture to the capture list
** 'base', nested inside a group capture. 'fd' indexes the first capture
** value, 'n' is the number of values (at least 1).
*/
static void adddyncaptures (const char *s, Capture *base, int n, int fd) {
int i;
/* Cgroup capture is already there */
assert(base[0].kind == Cgroup && base[0].siz == 0);
base[0].idx = 0; /* make it an anonymous group */
for (i = 1; i <= n; i++) { /* add runtime captures */
base[i].kind = Cruntime;
base[i].siz = 1; /* mark it as closed */
base[i].idx = fd + i - 1; /* stack index of capture value */
base[i].s = s;
}
base[i].kind = Cclose; /* close group */
base[i].siz = 1;
base[i].s = s;
}
/*
** Remove dynamic captures from the Lua stack (called in case of failure)
*/
static int removedyncap (lua_State *L, Capture *capture,
int level, int last) {
int id = finddyncap(capture + level, capture + last); /* index of 1st cap. */
int top = lua_gettop(L);
if (id == 0) return 0; /* no dynamic captures? */
lua_settop(L, id - 1); /* remove captures */
return top - id + 1; /* number of values removed */
}
/*
** Opcode interpreter
*/
const char *match (lua_State *L, const char *o, const char *s, const char *e,
Instruction *op, Capture *capture, int ptop) {
Stack stackbase[INITBACK];
Stack *stacklimit = stackbase + INITBACK;
Stack *stack = stackbase; /* point to first empty slot in stack */
int capsize = INITCAPSIZE;
int captop = 0; /* point to first empty slot in captures */
int ndyncap = 0; /* number of dynamic captures (in Lua stack) */
const Instruction *p = op; /* current instruction */
stack->p = &giveup; stack->s = s; stack->caplevel = 0; stack++;
lua_pushlightuserdata(L, stackbase);
for (;;) {
#if defined(DEBUG)
printf("s: |%s| stck:%d, dyncaps:%d, caps:%d ",
s, stack - getstackbase(L, ptop), ndyncap, captop);
printinst(op, p);
printcaplist(capture, capture + captop);
#endif
assert(stackidx(ptop) + ndyncap == lua_gettop(L) && ndyncap <= captop);
switch ((Opcode)p->i.code) {
case IEnd: {
assert(stack == getstackbase(L, ptop) + 1);
capture[captop].kind = Cclose;
capture[captop].s = NULL;
return s;
}
case IGiveup: {
assert(stack == getstackbase(L, ptop));
return NULL;
}
case IRet: {
assert(stack > getstackbase(L, ptop) && (stack - 1)->s == NULL);
p = (--stack)->p;
continue;
}
case IAny: {
if (s < e) { p++; s++; }
else goto fail;
continue;
}
case ITestAny: {
if (s < e) p += 2;
else p += getoffset(p);
continue;
}
case IChar: {
if ((byte)*s == p->i.aux && s < e) { p++; s++; }
else goto fail;
continue;
}
case ITestChar: {
if ((byte)*s == p->i.aux && s < e) p += 2;
else p += getoffset(p);
continue;
}
case ISet: {
int c = (byte)*s;
if (testchar((p+1)->buff, c) && s < e)
{ p += CHARSETINSTSIZE; s++; }
else goto fail;
continue;
}
case ITestSet: {
int c = (byte)*s;
if (testchar((p + 2)->buff, c) && s < e)
p += 1 + CHARSETINSTSIZE;
else p += getoffset(p);
continue;
}
case IBehind: {
int n = p->i.aux;
if (n > s - o) goto fail;
s -= n; p++;
continue;
}
case ISpan: {
for (; s < e; s++) {
int c = (byte)*s;
if (!testchar((p+1)->buff, c)) break;
}
p += CHARSETINSTSIZE;
continue;
}
case IJmp: {
p += getoffset(p);
continue;
}
case IChoice: {
if (stack == stacklimit)
stack = doublestack(L, &stacklimit, ptop);
stack->p = p + getoffset(p);
stack->s = s;
stack->caplevel = captop;
stack++;
p += 2;
continue;
}
case ICall: {
if (stack == stacklimit)
stack = doublestack(L, &stacklimit, ptop);
stack->s = NULL;
stack->p = p + 2; /* save return address */
stack++;
p += getoffset(p);
continue;
}
case ICommit: {
assert(stack > getstackbase(L, ptop) && (stack - 1)->s != NULL);
stack--;
p += getoffset(p);
continue;
}
case IPartialCommit: {
assert(stack > getstackbase(L, ptop) && (stack - 1)->s != NULL);
(stack - 1)->s = s;
(stack - 1)->caplevel = captop;
p += getoffset(p);
continue;
}
case IBackCommit: {
assert(stack > getstackbase(L, ptop) && (stack - 1)->s != NULL);
s = (--stack)->s;
captop = stack->caplevel;
p += getoffset(p);
continue;
}
case IFailTwice:
assert(stack > getstackbase(L, ptop));
stack--;
/* go through */
case IFail:
fail: { /* pattern failed: try to backtrack */
do { /* remove pending calls */
assert(stack > getstackbase(L, ptop));
s = (--stack)->s;
} while (s == NULL);
if (ndyncap > 0) /* is there matchtime captures? */
ndyncap -= removedyncap(L, capture, stack->caplevel, captop);
captop = stack->caplevel;
p = stack->p;
continue;
}
case ICloseRunTime: {
CapState cs;
int rem, res, n;
int fr = lua_gettop(L) + 1; /* stack index of first result */
cs.s = o; cs.L = L; cs.ocap = capture; cs.ptop = ptop;
n = runtimecap(&cs, capture + captop, s, &rem); /* call function */
captop -= n; /* remove nested captures */
fr -= rem; /* 'rem' items were popped from Lua stack */
res = resdyncaptures(L, fr, s - o, e - o); /* get result */
if (res == -1) /* fail? */
goto fail;
s = o + res; /* else update current position */
n = lua_gettop(L) - fr + 1; /* number of new captures */
ndyncap += n - rem; /* update number of dynamic captures */
if (n > 0) { /* any new capture? */
if ((captop += n + 2) >= capsize) {
capture = doublecap(L, capture, captop, ptop);
capsize = 2 * captop;
}
/* add new captures to 'capture' list */
adddyncaptures(s, capture + captop - n - 2, n, fr);
}
p++;
continue;
}
case ICloseCapture: {
const char *s1 = s;
assert(captop > 0);
/* if possible, turn capture into a full capture */
if (capture[captop - 1].siz == 0 &&
s1 - capture[captop - 1].s < UCHAR_MAX) {
capture[captop - 1].siz = s1 - capture[captop - 1].s + 1;
p++;
continue;
}
else {
capture[captop].siz = 1; /* mark entry as closed */
capture[captop].s = s;
goto pushcapture;
}
}
case IOpenCapture:
capture[captop].siz = 0; /* mark entry as open */
capture[captop].s = s;
goto pushcapture;
case IFullCapture:
capture[captop].siz = getoff(p) + 1; /* save capture size */
capture[captop].s = s - getoff(p);
/* goto pushcapture; */
pushcapture: {
capture[captop].idx = p->i.key;
capture[captop].kind = getkind(p);
if (++captop >= capsize) {
capture = doublecap(L, capture, captop, ptop);
capsize = 2 * captop;
}
p++;
continue;
}
default: assert(0); return NULL;
}
}
}
/* }====================================================== */