[p5sagit/p5-mst-13.2.git] / regcomp.h

/*    regcomp.h
 */

typedef OP OP_4tree;			/* Will be redefined later. */

/*
 * The "internal use only" fields in regexp.h are present to pass info from
 * compile to execute that permits the execute phase to run lots faster on
 * simple cases.  They are:
 *
 * regstart	sv that must begin a match; Nullch if none obvious
 * reganch	is the match anchored (at beginning-of-line only)?
 * regmust	string (pointer into program) that match must include, or NULL
 *  [regmust changed to SV* for bminstr()--law]
 * regmlen	length of regmust string
 *  [regmlen not used currently]
 *
 * Regstart and reganch permit very fast decisions on suitable starting points
 * for a match, cutting down the work a lot.  Regmust permits fast rejection
 * of lines that cannot possibly match.  The regmust tests are costly enough
 * that pregcomp() supplies a regmust only if the r.e. contains something
 * potentially expensive (at present, the only such thing detected is * or +
 * at the start of the r.e., which can involve a lot of backup).  Regmlen is
 * supplied because the test in pregexec() needs it and pregcomp() is computing
 * it anyway.
 * [regmust is now supplied always.  The tests that use regmust have a
 * heuristic that disables the test if it usually matches.]
 *
 * [In fact, we now use regmust in many cases to locate where the search
 * starts in the string, so if regback is >= 0, the regmust search is never
 * wasted effort.  The regback variable says how many characters back from
 * where regmust matched is the earliest possible start of the match.
 * For instance, /[a-z].foo/ has a regmust of 'foo' and a regback of 2.]
 */

/*
 * Structure for regexp "program".  This is essentially a linear encoding
 * of a nondeterministic finite-state machine (aka syntax charts or
 * "railroad normal form" in parsing technology).  Each node is an opcode
 * plus a "next" pointer, possibly plus an operand.  "Next" pointers of
 * all nodes except BRANCH implement concatenation; a "next" pointer with
 * a BRANCH on both ends of it is connecting two alternatives.  (Here we
 * have one of the subtle syntax dependencies:  an individual BRANCH (as
 * opposed to a collection of them) is never concatenated with anything
 * because of operator precedence.)  The operand of some types of node is
 * a literal string; for others, it is a node leading into a sub-FSM.  In
 * particular, the operand of a BRANCH node is the first node of the branch.
 * (NB this is *not* a tree structure:  the tail of the branch connects
 * to the thing following the set of BRANCHes.)  The opcodes are:
 */

/* definition	number	opnd?	meaning */
#define	END	 0	/* no	End of program. */
#define	BOL	 1	/* no	Match "" at beginning of line. */
#define MBOL	 2	/* no	Same, assuming multiline. */
#define SBOL	 3	/* no	Same, assuming singleline. */
#define	EOL	 4	/* no	Match "" at end of line. */
#define MEOL	 5	/* no	Same, assuming multiline. */
#define SEOL	 6	/* no	Same, assuming singleline. */
#define	ANY	 7	/* no	Match any one character (except newline). */
#define	SANY	 8	/* no	Match any one character. */
#define	ANYOF	 9	/* sv	Match character in (or not in) this class. */
#define	CURLY	10	/* sv	Match this simple thing {n,m} times. */
#define	CURLYX	11	/* sv	Match this complex thing {n,m} times. */
#define	BRANCH	12	/* node	Match this alternative, or the next... */
#define	BACK	13	/* no	Match "", "next" ptr points backward. */
#define	EXACT	14	/* sv	Match this string (preceded by length). */
#define	EXACTF	15	/* sv	Match this string, folded (prec. by length). */
#define	EXACTFL	16	/* sv	Match this string, folded in locale (w/len). */
#define	NOTHING	17	/* no	Match empty string. */
#define	STAR	18	/* node	Match this (simple) thing 0 or more times. */
#define	PLUS	19	/* node	Match this (simple) thing 1 or more times. */
#define BOUND	20	/* no	Match "" at any word boundary */
#define BOUNDL	21	/* no	Match "" at any word boundary */
#define NBOUND	22	/* no	Match "" at any word non-boundary */
#define NBOUNDL	23	/* no	Match "" at any word non-boundary */
#define REF	24	/* num	Match some already matched string */
#define	OPEN	25	/* num	Mark this point in input as start of #n. */
#define	CLOSE	26	/* num	Analogous to OPEN. */
#define MINMOD	27	/* no	Next operator is not greedy. */
#define GPOS	28	/* no	Matches where last m//g left off. */
#define IFMATCH	29	/* off	Succeeds if the following matches. */
#define UNLESSM	30	/* off	Fails if the following matches. */
#define SUCCEED	31	/* no	Return from a subroutine, basically. */
#define WHILEM	32	/* no	Do curly processing and see if rest matches. */
#define ALNUM	33	/* no	Match any alphanumeric character */
#define ALNUML	34 	/* no	Match any alphanumeric char in locale */
#define NALNUM	35	/* no	Match any non-alphanumeric character */
#define NALNUML	36	/* no	Match any non-alphanumeric char in locale */
#define SPACE	37	/* no	Match any whitespace character */
#define SPACEL	38	/* no	Match any whitespace char in locale */
#define NSPACE	39	/* no	Match any non-whitespace character */
#define NSPACEL	40	/* no	Match any non-whitespace char in locale */
#define DIGIT	41	/* no	Match any numeric character */
#define NDIGIT	42	/* no	Match any non-numeric character */
#define CURLYM	43	/* no	Match this medium-complex thing {n,m} times. */
#define CURLYN	44	/* no	Match next-after-this simple thing
			   {n,m} times, set parenths. */
#define	TAIL	45	/* no	Match empty string. Can jump here from outside. */
#define REFF	46      /* num  Match already matched string, folded */
#define REFFL	47      /* num  Match already matched string, folded in loc. */
#define EVAL	48      /* evl  Execute some Perl code. */
#define LONGJMP	49      /* off  Jump far away. */
#define BRANCHJ	50      /* off  BRANCH with long offset. */
#define IFTHEN	51      /* off  Switch, should be preceeded by switcher . */
#define GROUPP	52      /* num  Whether the group matched. */
#define LOGICAL	53	/* no	Next opcode should set the flag only. */
#define SUSPEND	54	/* off	"Independent" sub-RE. */
#define RENUM	55	/* off	Group with independently numbered parens. */
#define OPTIMIZED	56	/* off	Placeholder for dump. */

/*
 * Opcode notes:
 *
 * BRANCH	The set of branches constituting a single choice are hooked
 *		together with their "next" pointers, since precedence prevents
 *		anything being concatenated to any individual branch.  The
 *		"next" pointer of the last BRANCH in a choice points to the
 *		thing following the whole choice.  This is also where the
 *		final "next" pointer of each individual branch points; each
 *		branch starts with the operand node of a BRANCH node.
 *
 * BACK		Normal "next" pointers all implicitly point forward; BACK
 *		exists to make loop structures possible.
 *
 * STAR,PLUS	'?', and complex '*' and '+', are implemented as circular
 *		BRANCH structures using BACK.  Simple cases (one character
 *		per match) are implemented with STAR and PLUS for speed
 *		and to minimize recursive plunges.
 *
 * OPEN,CLOSE,GROUPP	...are numbered at compile time.
 */

#ifndef DOINIT
EXTCONST U8 regkind[];
#else
EXTCONST U8 regkind[] = {
	END,
	BOL,
	BOL,
	BOL,
	EOL,
	EOL,
	EOL,
	ANY,
	ANY,
	ANYOF,
	CURLY,
	CURLY,
	BRANCH,
	BACK,
	EXACT,
	EXACT,
	EXACT,
	NOTHING,
	STAR,
	PLUS,
	BOUND,
	BOUND,
	NBOUND,
	NBOUND,
	REF,
	OPEN,
	CLOSE,
	MINMOD,
	GPOS,
	BRANCHJ,
	BRANCHJ,
	END,
	WHILEM,
	ALNUM,
	ALNUM,
	NALNUM,
	NALNUM,
	SPACE,
	SPACE,
	NSPACE,
	NSPACE,
	DIGIT,
	NDIGIT,
	CURLY,
	CURLY,
	NOTHING,
	REF,
	REF,
	EVAL,
	LONGJMP,
	BRANCHJ,
	BRANCHJ,
	GROUPP,
	LOGICAL,
	BRANCHJ,
	BRANCHJ,
	NOTHING,
};
#endif

/* The following have no fixed length. char* since we do strchr on it. */
#ifndef DOINIT
EXTCONST char varies[];
#else
EXTCONST char varies[] = {
    BRANCH, BACK, STAR, PLUS, CURLY, CURLYX, REF, REFF, REFFL, 
    WHILEM, CURLYM, CURLYN, BRANCHJ, IFTHEN, SUSPEND, 0
};
#endif

/* The following always have a length of 1. char* since we do strchr on it. */
#ifndef DOINIT
EXTCONST char simple[];
#else
EXTCONST char simple[] = {
    ANY, SANY, ANYOF,
    ALNUM, ALNUML, NALNUM, NALNUML,
    SPACE, SPACEL, NSPACE, NSPACEL,
    DIGIT, NDIGIT, 0
};
#endif

/*
 * A node is one char of opcode followed by two chars of "next" pointer.
 * "Next" pointers are stored as two 8-bit pieces, high order first.  The
 * value is a positive offset from the opcode of the node containing it.
 * An operand, if any, simply follows the node.  (Note that much of the
 * code generation knows about this implicit relationship.)
 *
 * Using two bytes for the "next" pointer is vast overkill for most things,
 * but allows patterns to get big without disasters.
 *
 * [The "next" pointer is always aligned on an even
 * boundary, and reads the offset directly as a short.  Also, there is no
 * special test to reverse the sign of BACK pointers since the offset is
 * stored negative.]
 */

struct regnode_string {
    U8	flags;
    U8  type;
    U16 next_off;
    U8 string[1];
};

struct regnode_1 {
    U8	flags;
    U8  type;
    U16 next_off;
    U32 arg1;
};

struct regnode_2 {
    U8	flags;
    U8  type;
    U16 next_off;
    U16 arg1;
    U16 arg2;
};

/* XXX fix this description.
   Impose a limit of REG_INFTY on various pattern matching operations
   to limit stack growth and to avoid "infinite" recursions.
*/
/* The default size for REG_INFTY is I16_MAX, which is the same as
   SHORT_MAX (see perl.h).  Unfortunately I16 isn't necessarily 16 bits
   (see handy.h).  On the Cray C90, sizeof(short)==4 and hence I16_MAX is
   ((1<<31)-1), while on the Cray T90, sizeof(short)==8 and I16_MAX is
   ((1<<63)-1).  To limit stack growth to reasonable sizes, supply a
   smaller default.
	--Andy Dougherty  11 June 1998
*/
#if SHORTSIZE > 2
#  ifndef REG_INFTY
#    define REG_INFTY ((1<<15)-1)
#  endif
#endif

#ifndef REG_INFTY
#  define REG_INFTY I16_MAX
#endif

#define ARG_VALUE(arg) (arg)
#define ARG__SET(arg,val) ((arg) = (val))

#define ARG(p) ARG_VALUE(ARG_LOC(p))
#define ARG1(p) ARG_VALUE(ARG1_LOC(p))
#define ARG2(p) ARG_VALUE(ARG2_LOC(p))
#define ARG_SET(p, val) ARG__SET(ARG_LOC(p), (val))
#define ARG1_SET(p, val) ARG__SET(ARG1_LOC(p), (val))
#define ARG2_SET(p, val) ARG__SET(ARG2_LOC(p), (val))

#ifndef lint
#  define NEXT_OFF(p) ((p)->next_off)
#  define NODE_ALIGN(node)
#  define NODE_ALIGN_FILL(node) ((node)->flags = 0xde) /* deadbeef */
#else /* lint */
#  define NEXT_OFF(p) 0
#  define NODE_ALIGN(node)
#  define NODE_ALIGN_FILL(node)
#endif /* lint */

#define SIZE_ALIGN NODE_ALIGN

#define	OP(p)		((p)->type)
#define	OPERAND(p)	(((struct regnode_string *)p)->string)
#define	NODE_ALIGN(node)
#define	ARG_LOC(p)	(((struct regnode_1 *)p)->arg1)
#define	ARG1_LOC(p)	(((struct regnode_2 *)p)->arg1)
#define	ARG2_LOC(p)	(((struct regnode_2 *)p)->arg2)
#define NODE_STEP_REGNODE	1	/* sizeof(regnode)/sizeof(regnode) */
#define EXTRA_STEP_2ARGS	EXTRA_SIZE(struct regnode_2)

#define NODE_STEP_B	4

#define	NEXTOPER(p)	((p) + NODE_STEP_REGNODE)
#define	PREVOPER(p)	((p) - NODE_STEP_REGNODE)

#define FILL_ADVANCE_NODE(ptr, op) STMT_START { \
    (ptr)->type = op;    (ptr)->next_off = 0;   (ptr)++; } STMT_END
#define FILL_ADVANCE_NODE_ARG(ptr, op, arg) STMT_START { \
    ARG_SET(ptr, arg);  FILL_ADVANCE_NODE(ptr, op); (ptr) += 1; } STMT_END

#define MAGIC 0234

#define SIZE_ONLY (regcode == &regdummy)

/* Flags for first parameter byte of ANYOF */
#define ANYOF_INVERT	0x40
#define ANYOF_FOLD	0x20
#define ANYOF_LOCALE	0x10
#define ANYOF_ISA	0x0F
#define ANYOF_ALNUML	 0x08
#define ANYOF_NALNUML	 0x04
#define ANYOF_SPACEL	 0x02
#define ANYOF_NSPACEL	 0x01

/* Utility macros for bitmap of ANYOF */
#define ANYOF_BYTE(p,c)     (p)[1 + (((c) >> 3) & 31)]
#define ANYOF_BIT(c)        (1 << ((c) & 7))
#define ANYOF_SET(p,c)      (ANYOF_BYTE(p,c) |=  ANYOF_BIT(c))
#define ANYOF_CLEAR(p,c)    (ANYOF_BYTE(p,c) &= ~ANYOF_BIT(c))
#define ANYOF_TEST(p,c)     (ANYOF_BYTE(p,c) &   ANYOF_BIT(c))

#define ANY_SKIP ((33 - 1)/sizeof(regnode) + 1)

/*
 * Utility definitions.
 */
#ifndef lint
#ifndef CHARMASK
#define	UCHARAT(p)	((int)*(unsigned char *)(p))
#else
#define	UCHARAT(p)	((int)*(p)&CHARMASK)
#endif
#else /* lint */
#define UCHARAT(p)	regdummy
#endif /* lint */

#define	FAIL(m)		croak    ("/%.127s/: %s",  regprecomp,m)
#define	FAIL2(pat,m)	re_croak2("/%.127s/: ",pat,regprecomp,m)

#define EXTRA_SIZE(guy) ((sizeof(guy)-1)/sizeof(struct regnode))

#ifdef REG_COMP_C
const static U8 regarglen[] = {
    0,0,0,0,0,0,0,0,0,0,
    /*CURLY*/ EXTRA_SIZE(struct regnode_2), 
    /*CURLYX*/ EXTRA_SIZE(struct regnode_2),
    0,0,0,0,0,0,0,0,0,0,0,0,
    /*REF*/ EXTRA_SIZE(struct regnode_1), 
    /*OPEN*/ EXTRA_SIZE(struct regnode_1),
    /*CLOSE*/ EXTRA_SIZE(struct regnode_1),
    0,0,
    /*IFMATCH*/ EXTRA_SIZE(struct regnode_1),
    /*UNLESSM*/ EXTRA_SIZE(struct regnode_1),
    0,0,0,0,0,0,0,0,0,0,0,0,
    /*CURLYM*/ EXTRA_SIZE(struct regnode_2),
    /*CURLYN*/ EXTRA_SIZE(struct regnode_2),
    0,
    /*REFF*/ EXTRA_SIZE(struct regnode_1),
    /*REFFL*/ EXTRA_SIZE(struct regnode_1),
    /*EVAL*/ EXTRA_SIZE(struct regnode_1),
    /*LONGJMP*/ EXTRA_SIZE(struct regnode_1),
    /*BRANCHJ*/ EXTRA_SIZE(struct regnode_1),
    /*IFTHEN*/ EXTRA_SIZE(struct regnode_1),
    /*GROUPP*/ EXTRA_SIZE(struct regnode_1),
    /*LOGICAL*/ 0,
    /*SUSPEND*/ EXTRA_SIZE(struct regnode_1),
    /*RENUM*/ EXTRA_SIZE(struct regnode_1), 0,
};

const static char reg_off_by_arg[] = {
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,	/* 0 .. 15 */
    0,0,0,0,0,0,0,0,0,0,0,0,0, /*IFMATCH*/ 2, /*UNLESSM*/ 2, 0,
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,	/* 32 .. 47 */
    0, /*LONGJMP*/ 1, /*BRANCHJ*/ 1, /*IFTHEN*/ 1, 0, 0,
    /*RENUM*/ 1, /*RENUM*/ 1,0,
};
#endif

#define REG_SEEN_ZERO_LEN	1
#define REG_SEEN_LOOKBEHIND	2
#define REG_SEEN_GPOS		4
#define REG_SEEN_EVAL		8
Commit	Line	Data
a0d0e21e	1	/* regcomp.h
a687059c	2	*/
a687059c	3
c277df42	4	typedef OP OP_4tree; /* Will be redefined later. */
c277df42	5
a687059c	6	/*
	7	* The "internal use only" fields in regexp.h are present to pass info from
	8	* compile to execute that permits the execute phase to run lots faster on
	9	* simple cases. They are:
	10	*
79072805	11	* regstart sv that must begin a match; Nullch if none obvious
a687059c	12	* reganch is the match anchored (at beginning-of-line only)?
a687059c	13	* regmust string (pointer into program) that match must include, or NULL
79072805	14	* [regmust changed to SV* for bminstr()--law]
a687059c	15	* regmlen length of regmust string
	16	* [regmlen not used currently]
	17	*
	18	* Regstart and reganch permit very fast decisions on suitable starting points
	19	* for a match, cutting down the work a lot. Regmust permits fast rejection
	20	* of lines that cannot possibly match. The regmust tests are costly enough
e50aee73	21	* that pregcomp() supplies a regmust only if the r.e. contains something
a687059c	22	* potentially expensive (at present, the only such thing detected is * or +
a687059c	23	* at the start of the r.e., which can involve a lot of backup). Regmlen is
e50aee73	24	* supplied because the test in pregexec() needs it and pregcomp() is computing
a687059c	25	* it anyway.
	26	* [regmust is now supplied always. The tests that use regmust have a
	27	* heuristic that disables the test if it usually matches.]
	28	*
	29	* [In fact, we now use regmust in many cases to locate where the search
	30	* starts in the string, so if regback is >= 0, the regmust search is never
	31	* wasted effort. The regback variable says how many characters back from
	32	* where regmust matched is the earliest possible start of the match.
	33	* For instance, /[a-z].foo/ has a regmust of 'foo' and a regback of 2.]
	34	*/
	35
	36	/*
	37	* Structure for regexp "program". This is essentially a linear encoding
	38	* of a nondeterministic finite-state machine (aka syntax charts or
	39	* "railroad normal form" in parsing technology). Each node is an opcode
	40	* plus a "next" pointer, possibly plus an operand. "Next" pointers of
	41	* all nodes except BRANCH implement concatenation; a "next" pointer with
	42	* a BRANCH on both ends of it is connecting two alternatives. (Here we
	43	* have one of the subtle syntax dependencies: an individual BRANCH (as
	44	* opposed to a collection of them) is never concatenated with anything
	45	* because of operator precedence.) The operand of some types of node is
	46	* a literal string; for others, it is a node leading into a sub-FSM. In
	47	* particular, the operand of a BRANCH node is the first node of the branch.
	48	* (NB this is not a tree structure: the tail of the branch connects
	49	* to the thing following the set of BRANCHes.) The opcodes are:
	50	*/
	51
	52	/* definition number opnd? meaning */
bbce6d69	53	#define END 0 /* no End of program. */
	54	#define BOL 1 /* no Match "" at beginning of line. */
	55	#define MBOL 2 /* no Same, assuming multiline. */
	56	#define SBOL 3 /* no Same, assuming singleline. */
	57	#define EOL 4 /* no Match "" at end of line. */
	58	#define MEOL 5 /* no Same, assuming multiline. */
	59	#define SEOL 6 /* no Same, assuming singleline. */
	60	#define ANY 7 /* no Match any one character (except newline). */
	61	#define SANY 8 /* no Match any one character. */
	62	#define ANYOF 9 /* sv Match character in (or not in) this class. */
a0d0e21e	63	#define CURLY 10 /* sv Match this simple thing {n,m} times. */
	64	#define CURLYX 11 /* sv Match this complex thing {n,m} times. */
	65	#define BRANCH 12 /* node Match this alternative, or the next... */
	66	#define BACK 13 /* no Match "", "next" ptr points backward. */
bbce6d69	67	#define EXACT 14 /* sv Match this string (preceded by length). */
	68	#define EXACTF 15 /* sv Match this string, folded (prec. by length). */
	69	#define EXACTFL 16 /* sv Match this string, folded in locale (w/len). */
	70	#define NOTHING 17 /* no Match empty string. */
	71	#define STAR 18 /* node Match this (simple) thing 0 or more times. */
	72	#define PLUS 19 /* node Match this (simple) thing 1 or more times. */
a0d0e21e	73	#define BOUND 20 /* no Match "" at any word boundary */
bbce6d69	74	#define BOUNDL 21 /* no Match "" at any word boundary */
	75	#define NBOUND 22 /* no Match "" at any word non-boundary */
	76	#define NBOUNDL 23 /* no Match "" at any word non-boundary */
c277df42	77	#define REF 24 /* num Match some already matched string */
	78	#define OPEN 25 /* num Mark this point in input as start of #n. */
	79	#define CLOSE 26 /* num Analogous to OPEN. */
	80	#define MINMOD 27 /* no Next operator is not greedy. */
	81	#define GPOS 28 /* no Matches where last m//g left off. */
	82	#define IFMATCH 29 /* off Succeeds if the following matches. */
	83	#define UNLESSM 30 /* off Fails if the following matches. */
	84	#define SUCCEED 31 /* no Return from a subroutine, basically. */
	85	#define WHILEM 32 /* no Do curly processing and see if rest matches. */
	86	#define ALNUM 33 /* no Match any alphanumeric character */
	87	#define ALNUML 34 /* no Match any alphanumeric char in locale */
	88	#define NALNUM 35 /* no Match any non-alphanumeric character */
	89	#define NALNUML 36 /* no Match any non-alphanumeric char in locale */
	90	#define SPACE 37 /* no Match any whitespace character */
	91	#define SPACEL 38 /* no Match any whitespace char in locale */
	92	#define NSPACE 39 /* no Match any non-whitespace character */
	93	#define NSPACEL 40 /* no Match any non-whitespace char in locale */
	94	#define DIGIT 41 /* no Match any numeric character */
	95	#define NDIGIT 42 /* no Match any non-numeric character */
	96	#define CURLYM 43 /* no Match this medium-complex thing {n,m} times. */
	97	#define CURLYN 44 /* no Match next-after-this simple thing
	98	{n,m} times, set parenths. */
	99	#define TAIL 45 /* no Match empty string. Can jump here from outside. */
	100	#define REFF 46 /* num Match already matched string, folded */
	101	#define REFFL 47 /* num Match already matched string, folded in loc. */
	102	#define EVAL 48 /* evl Execute some Perl code. */
e91177ed	103	#define LONGJMP 49 /* off Jump far away. */
e91177ed	104	#define BRANCHJ 50 /* off BRANCH with long offset. */
c277df42	105	#define IFTHEN 51 /* off Switch, should be preceeded by switcher . */
	106	#define GROUPP 52 /* num Whether the group matched. */
	107	#define LOGICAL 53 /* no Next opcode should set the flag only. */
	108	#define SUSPEND 54 /* off "Independent" sub-RE. */
	109	#define RENUM 55 /* off Group with independently numbered parens. */
	110	#define OPTIMIZED 56 /* off Placeholder for dump. */
a687059c	111
	112	/*
	113	* Opcode notes:
	114	*
	115	* BRANCH The set of branches constituting a single choice are hooked
	116	* together with their "next" pointers, since precedence prevents
	117	* anything being concatenated to any individual branch. The
	118	* "next" pointer of the last BRANCH in a choice points to the
	119	* thing following the whole choice. This is also where the
	120	* final "next" pointer of each individual branch points; each
	121	* branch starts with the operand node of a BRANCH node.
	122	*
	123	* BACK Normal "next" pointers all implicitly point forward; BACK
	124	* exists to make loop structures possible.
	125	*
	126	* STAR,PLUS '?', and complex '*' and '+', are implemented as circular
	127	* BRANCH structures using BACK. Simple cases (one character
	128	* per match) are implemented with STAR and PLUS for speed
	129	* and to minimize recursive plunges.
	130	*
c277df42	131	* OPEN,CLOSE,GROUPP ...are numbered at compile time.
a687059c	132	*/
a687059c	133
fe14fcc3	134	#ifndef DOINIT
161b471a	135	EXTCONST U8 regkind[];
a0d0e21e	136	#else
161b471a	137	EXTCONST U8 regkind[] = {
a0d0e21e	138	END,
	139	BOL,
	140	BOL,
	141	BOL,
	142	EOL,
	143	EOL,
	144	EOL,
	145	ANY,
	146	ANY,
	147	ANYOF,
	148	CURLY,
	149	CURLY,
	150	BRANCH,
	151	BACK,
bbce6d69	152	EXACT,
	153	EXACT,
	154	EXACT,
a0d0e21e	155	NOTHING,
	156	STAR,
	157	PLUS,
bbce6d69	158	BOUND,
a0d0e21e	159	BOUND,
a0d0e21e	160	NBOUND,
bbce6d69	161	NBOUND,
a0d0e21e	162	REF,
	163	OPEN,
	164	CLOSE,
	165	MINMOD,
774d564b	166	GPOS,
c277df42	167	BRANCHJ,
c277df42	168	BRANCHJ,
a0d0e21e	169	END,
bbce6d69	170	WHILEM,
	171	ALNUM,
	172	ALNUM,
	173	NALNUM,
	174	NALNUM,
	175	SPACE,
	176	SPACE,
	177	NSPACE,
	178	NSPACE,
	179	DIGIT,
	180	NDIGIT,
c277df42	181	CURLY,
	182	CURLY,
	183	NOTHING,
	184	REF,
	185	REF,
	186	EVAL,
	187	LONGJMP,
	188	BRANCHJ,
	189	BRANCHJ,
	190	GROUPP,
	191	LOGICAL,
	192	BRANCHJ,
	193	BRANCHJ,
	194	NOTHING,
a0d0e21e	195	};
fe14fcc3	196	#endif
fe14fcc3	197
c277df42	198	/* The following have no fixed length. char* since we do strchr on it. */
a687059c	199	#ifndef DOINIT
fc1ce8cc	200	EXTCONST char varies[];
a687059c	201	#else
fc1ce8cc	202	EXTCONST char varies[] = {
c277df42	203	BRANCH, BACK, STAR, PLUS, CURLY, CURLYX, REF, REFF, REFFL,
c277df42	204	WHILEM, CURLYM, CURLYN, BRANCHJ, IFTHEN, SUSPEND, 0
bbce6d69	205	};
a687059c	206	#endif
a687059c	207
c277df42	208	/* The following always have a length of 1. char* since we do strchr on it. */
a687059c	209	#ifndef DOINIT
fc1ce8cc	210	EXTCONST char simple[];
a687059c	211	#else
fc1ce8cc	212	EXTCONST char simple[] = {
bbce6d69	213	ANY, SANY, ANYOF,
	214	ALNUM, ALNUML, NALNUM, NALNUML,
	215	SPACE, SPACEL, NSPACE, NSPACEL,
	216	DIGIT, NDIGIT, 0
	217	};
a687059c	218	#endif
a687059c	219
a687059c	220	/*
	221	* A node is one char of opcode followed by two chars of "next" pointer.
	222	* "Next" pointers are stored as two 8-bit pieces, high order first. The
	223	* value is a positive offset from the opcode of the node containing it.
	224	* An operand, if any, simply follows the node. (Note that much of the
	225	* code generation knows about this implicit relationship.)
	226	*
	227	* Using two bytes for the "next" pointer is vast overkill for most things,
	228	* but allows patterns to get big without disasters.
	229	*
e91177ed	230	* [The "next" pointer is always aligned on an even
a687059c	231	* boundary, and reads the offset directly as a short. Also, there is no
	232	* special test to reverse the sign of BACK pointers since the offset is
	233	* stored negative.]
	234	*/
	235
c277df42	236	struct regnode_string {
	237	U8 flags;
	238	U8 type;
	239	U16 next_off;
	240	U8 string[1];
	241	};
a687059c	242
c277df42	243	struct regnode_1 {
	244	U8 flags;
	245	U8 type;
	246	U16 next_off;
	247	U32 arg1;
	248	};
	249
	250	struct regnode_2 {
	251	U8 flags;
	252	U8 type;
	253	U16 next_off;
	254	U16 arg1;
	255	U16 arg2;
	256	};
	257
9c7e81e8	258	/* XXX fix this description.
	259	Impose a limit of REG_INFTY on various pattern matching operations
	260	to limit stack growth and to avoid "infinite" recursions.
	261	*/
	262	/* The default size for REG_INFTY is I16_MAX, which is the same as
	263	SHORT_MAX (see perl.h). Unfortunately I16 isn't necessarily 16 bits
	264	(see handy.h). On the Cray C90, sizeof(short)==4 and hence I16_MAX is
	265	((1<<31)-1), while on the Cray T90, sizeof(short)==8 and I16_MAX is
	266	((1<<63)-1). To limit stack growth to reasonable sizes, supply a
	267	smaller default.
	268	--Andy Dougherty 11 June 1998
	269	*/
	270	#if SHORTSIZE > 2
	271	# ifndef REG_INFTY
	272	# define REG_INFTY ((1<<15)-1)
	273	# endif
	274	#endif
	275
	276	#ifndef REG_INFTY
83cfe48c	277	# define REG_INFTY I16_MAX
83cfe48c	278	#endif
a687059c	279
e91177ed	280	#define ARG_VALUE(arg) (arg)
e91177ed	281	#define ARG__SET(arg,val) ((arg) = (val))
c277df42	282
	283	#define ARG(p) ARG_VALUE(ARG_LOC(p))
	284	#define ARG1(p) ARG_VALUE(ARG1_LOC(p))
	285	#define ARG2(p) ARG_VALUE(ARG2_LOC(p))
	286	#define ARG_SET(p, val) ARG__SET(ARG_LOC(p), (val))
	287	#define ARG1_SET(p, val) ARG__SET(ARG1_LOC(p), (val))
	288	#define ARG2_SET(p, val) ARG__SET(ARG2_LOC(p), (val))
	289
	290	#ifndef lint
e91177ed	291	# define NEXT_OFF(p) ((p)->next_off)
	292	# define NODE_ALIGN(node)
	293	# define NODE_ALIGN_FILL(node) ((node)->flags = 0xde) /* deadbeef */
a687059c	294	#else /* lint */
c277df42	295	# define NEXT_OFF(p) 0
e91177ed	296	# define NODE_ALIGN(node)
e91177ed	297	# define NODE_ALIGN_FILL(node)
a687059c	298	#endif /* lint */
a687059c	299
c277df42	300	#define SIZE_ALIGN NODE_ALIGN
c277df42	301
e91177ed	302	#define OP(p) ((p)->type)
	303	#define OPERAND(p) (((struct regnode_string *)p)->string)
	304	#define NODE_ALIGN(node)
	305	#define ARG_LOC(p) (((struct regnode_1 *)p)->arg1)
	306	#define ARG1_LOC(p) (((struct regnode_2 *)p)->arg1)
	307	#define ARG2_LOC(p) (((struct regnode_2 *)p)->arg2)
	308	#define NODE_STEP_REGNODE 1 /* sizeof(regnode)/sizeof(regnode) */
	309	#define EXTRA_STEP_2ARGS EXTRA_SIZE(struct regnode_2)
	310
	311	#define NODE_STEP_B 4
c277df42	312
	313	#define NEXTOPER(p) ((p) + NODE_STEP_REGNODE)
	314	#define PREVOPER(p) ((p) - NODE_STEP_REGNODE)
	315
e91177ed	316	#define FILL_ADVANCE_NODE(ptr, op) STMT_START { \
c277df42	317	(ptr)->type = op; (ptr)->next_off = 0; (ptr)++; } STMT_END
e91177ed	318	#define FILL_ADVANCE_NODE_ARG(ptr, op, arg) STMT_START { \
c277df42	319	ARG_SET(ptr, arg); FILL_ADVANCE_NODE(ptr, op); (ptr) += 1; } STMT_END
a687059c	320
	321	#define MAGIC 0234
	322
c277df42	323	#define SIZE_ONLY (regcode == &regdummy)
c277df42	324
bbce6d69	325	/* Flags for first parameter byte of ANYOF */
	326	#define ANYOF_INVERT 0x40
	327	#define ANYOF_FOLD 0x20
	328	#define ANYOF_LOCALE 0x10
	329	#define ANYOF_ISA 0x0F
	330	#define ANYOF_ALNUML 0x08
	331	#define ANYOF_NALNUML 0x04
	332	#define ANYOF_SPACEL 0x02
	333	#define ANYOF_NSPACEL 0x01
	334
ae5c130c	335	/* Utility macros for bitmap of ANYOF */
	336	#define ANYOF_BYTE(p,c) (p)[1 + (((c) >> 3) & 31)]
	337	#define ANYOF_BIT(c) (1 << ((c) & 7))
	338	#define ANYOF_SET(p,c) (ANYOF_BYTE(p,c) \|= ANYOF_BIT(c))
	339	#define ANYOF_CLEAR(p,c) (ANYOF_BYTE(p,c) &= ~ANYOF_BIT(c))
	340	#define ANYOF_TEST(p,c) (ANYOF_BYTE(p,c) & ANYOF_BIT(c))
	341
c277df42	342	#define ANY_SKIP ((33 - 1)/sizeof(regnode) + 1)
c277df42	343
a687059c	344	/*
	345	* Utility definitions.
	346	*/
	347	#ifndef lint
2304df62	348	#ifndef CHARMASK
a687059c	349	#define UCHARAT(p) ((int)(unsigned char )(p))
a687059c	350	#else
2304df62	351	#define UCHARAT(p) ((int)*(p)&CHARMASK)
a687059c	352	#endif
	353	#else /* lint */
	354	#define UCHARAT(p) regdummy
	355	#endif /* lint */
	356
c277df42	357	#define FAIL(m) croak ("/%.127s/: %s", regprecomp,m)
	358	#define FAIL2(pat,m) re_croak2("/%.127s/: ",pat,regprecomp,m)
	359
	360	#define EXTRA_SIZE(guy) ((sizeof(guy)-1)/sizeof(struct regnode))
	361
	362	#ifdef REG_COMP_C
	363	const static U8 regarglen[] = {
c277df42	364	0,0,0,0,0,0,0,0,0,0,
	365	/CURLY/ EXTRA_SIZE(struct regnode_2),
	366	/CURLYX/ EXTRA_SIZE(struct regnode_2),
	367	0,0,0,0,0,0,0,0,0,0,0,0,
	368	/REF/ EXTRA_SIZE(struct regnode_1),
	369	/OPEN/ EXTRA_SIZE(struct regnode_1),
	370	/CLOSE/ EXTRA_SIZE(struct regnode_1),
	371	0,0,
	372	/IFMATCH/ EXTRA_SIZE(struct regnode_1),
	373	/UNLESSM/ EXTRA_SIZE(struct regnode_1),
	374	0,0,0,0,0,0,0,0,0,0,0,0,
	375	/CURLYM/ EXTRA_SIZE(struct regnode_2),
	376	/CURLYN/ EXTRA_SIZE(struct regnode_2),
	377	0,
	378	/REFF/ EXTRA_SIZE(struct regnode_1),
	379	/REFFL/ EXTRA_SIZE(struct regnode_1),
	380	/EVAL/ EXTRA_SIZE(struct regnode_1),
	381	/LONGJMP/ EXTRA_SIZE(struct regnode_1),
	382	/BRANCHJ/ EXTRA_SIZE(struct regnode_1),
	383	/IFTHEN/ EXTRA_SIZE(struct regnode_1),
	384	/GROUPP/ EXTRA_SIZE(struct regnode_1),
	385	/LOGICAL/ 0,
	386	/SUSPEND/ EXTRA_SIZE(struct regnode_1),
	387	/RENUM/ EXTRA_SIZE(struct regnode_1), 0,
c277df42	388	};
	389
	390	const static char reg_off_by_arg[] = {
	391	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0 .. 15 */
	392	0,0,0,0,0,0,0,0,0,0,0,0,0, /IFMATCH/ 2, /UNLESSM/ 2, 0,
	393	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 32 .. 47 */
	394	0, /LONGJMP/ 1, /BRANCHJ/ 1, /IFTHEN/ 1, 0, 0,
	395	/RENUM/ 1, /RENUM/ 1,0,
	396	};
	397	#endif
	398
c277df42	399	#define REG_SEEN_ZERO_LEN 1
	400	#define REG_SEEN_LOOKBEHIND 2
	401	#define REG_SEEN_GPOS 4
ce862d02	402	#define REG_SEEN_EVAL 8