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authorVsevolod Stakhov <vsevolod@highsecure.ru>2018-05-23 18:14:15 +0100
committerVsevolod Stakhov <vsevolod@highsecure.ru>2018-05-23 18:14:15 +0100
commit714eb56e1760fdfb26afccde92664d3a2f1e8435 (patch)
tree84d1399acbb92f852b4bd64f9ea5412680b0c6ab /contrib/lpeg/lpcode.c
parent220a51ff68013dd668a45b78c60a7b8bfc10f074 (diff)
downloadrspamd-714eb56e1760fdfb26afccde92664d3a2f1e8435.tar.gz
rspamd-714eb56e1760fdfb26afccde92664d3a2f1e8435.zip
[Minor] Move lua contrib libraries to lua- prefix
Diffstat (limited to 'contrib/lpeg/lpcode.c')
-rw-r--r--contrib/lpeg/lpcode.c986
1 files changed, 0 insertions, 986 deletions
diff --git a/contrib/lpeg/lpcode.c b/contrib/lpeg/lpcode.c
deleted file mode 100644
index 6feefeb43..000000000
--- a/contrib/lpeg/lpcode.c
+++ /dev/null
@@ -1,986 +0,0 @@
-/*
-** $Id: lpcode.c,v 1.23 2015/06/12 18:36:47 roberto Exp $
-** Copyright 2007, Lua.org & PUC-Rio (see 'lpeg.html' for license)
-*/
-
-#include <limits.h>
-
-
-#include "lua.h"
-#include "lauxlib.h"
-
-#include "lptypes.h"
-#include "lpcode.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 (returns IFail), singleton (IChar),
-** full (IAny), or none of those (ISet). When singleton, '*c' returns
-** which character it is. (When generic set, the set was the input,
-** so there is no need to return it.)
-*/
-static Opcode charsettype (const byte *cs, int *c) {
- int count = 0; /* number of characters in the set */
- int i;
- int candidate = -1; /* candidate position for the singleton char */
- for (i = 0; i < CHARSETSIZE; i++) { /* for each byte */
- int b = cs[i];
- if (b == 0) { /* is byte empty? */
- if (count > 1) /* was set neither empty nor singleton? */
- return ISet; /* neither full nor empty nor singleton */
- /* else set is still empty or singleton */
- }
- else if (b == 0xFF) { /* is byte full? */
- if (count < (i * BITSPERCHAR)) /* was set not full? */
- return ISet; /* neither full nor empty nor singleton */
- else count += BITSPERCHAR; /* set is still full */
- }
- else if ((b & (b - 1)) == 0) { /* has byte only one bit? */
- if (count > 0) /* was set not empty? */
- return ISet; /* neither full nor empty nor singleton */
- 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;
-}
-
-static int cs_disjoint (const Charset *cs1, const Charset *cs2) {
- loopset(i, if ((cs1->cs[i] & cs2->cs[i]) != 0) return 0;)
- return 1;
-}
-
-
-/*
-** If 'tree' is a 'char' pattern (TSet, TChar, TAny), convert it into a
-** charset and return 1; else return 0.
-*/
-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 characters to the set */
- return 1;
- }
- default: return 0;
- }
-}
-
-
-/*
-** Check whether a pattern tree has captures
-*/
-int hascaptures (TTree *tree) {
- tailcall:
- switch (tree->tag) {
- case TCapture: case TRunTime:
- return 1;
- case TCall:
- tree = sib2(tree); goto tailcall; /* return hascaptures(sib2(tree)); */
- case TOpenCall: assert(0);
- 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 approximation:
-** match p ax -> x (for some x) ==> a belongs to first(p)
-** or
-** a not in first(p) ==> match p ax -> fail (for all x)
-**
-** The set 'follow' is the first set of what follows the
-** pattern (full set if nothing follows it).
-**
-** The function returns 0 when this resulting set can be used for
-** test instructions that avoid the pattern altogether.
-** A non-zero return can happen for two reasons:
-** 1) match p '' -> '' ==> return has bit 1 set
-** (tests cannot be used because they would always fail for an empty input);
-** 2) there is a match-time capture ==> return has bit 2 set
-** (optimizations should not bypass match-time captures).
-*/
-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; /* accepts the empty string */
- }
- 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))) {
- /* when p1 is not nullable, p2 has nothing to contribute;
- 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' only 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 'headfail(tree)' true, then 'tree' 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 as the last thing inside an optional pattern (so, if that
-** code is optional too, it can reuse the 'IChoice' already in place for
-** the outer pattern). 'tt' points to a previous test protecting this
-** code (or NOINST). 'fl' is the follow set of the pattern.
-*/
-static void codegen (CompileState *compst, TTree *tree, int opt, int tt,
- const Charset *fl);
-
-
-void realloccode (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)
- realloccode(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;
-}
-
-
-/*
-** Add an instruction followed by space for an offset (to be set later)
-*/
-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;
-}
-
-
-/*
-** Set the offset of an instruction
-*/
-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 the optional capture 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)
-
-
-/*
-** Patch 'instruction' to jump to 'target'
-*/
-static void jumptothere (CompileState *compst, int instruction, int target) {
- if (instruction >= 0)
- setoffset(compst, instruction, target - instruction);
-}
-
-
-/*
-** Patch 'instruction' to jump to current position
-*/
-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 or
-** 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 reuse
-** 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(first(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);
-}
-
-
-/*
-** Repetition; 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 repetition 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, 0, 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 auxiliary functions
-** according to kind of tree. ('needfollow' should return true
-** only for consructions that use 'fl'.)
-*/
-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])) {
- redo:
- 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 */
- goto redo; /* reoptimize its label */
- }
- 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;
- realloccode(L, p, 2); /* minimum initial size */
- codegen(&compst, p->tree, 0, NOINST, fullset);
- addinstruction(&compst, IEnd, 0);
- realloccode(L, p, compst.ncode); /* set final size */
- peephole(&compst);
- return p->code;
-}
-
-
-/* }====================================================== */
-
generated by cgit v1.2.3 (git 2.39.1) at 2025-03-27 21:00:49 +0000