source: trunk/third/perl/regcomp.h @ 14545

/*    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:
 */

/*
 * 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  str_len;
    U8  type;
    U16 next_off;
    char 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;
};

#define ANYOF_BITMAP_SIZE       32      /* 256 b/(8 b/B) */
#define ANYOF_CLASSBITMAP_SIZE   4

struct regnode_charclass {
    U8  flags;
    U8  type;
    U16 next_off;
    char bitmap[ANYOF_BITMAP_SIZE];
};

struct regnode_charclass_class {
    U8  flags;
    U8  type;
    U16 next_off;
    char bitmap[ANYOF_BITMAP_SIZE];
    char classflags[ANYOF_CLASSBITMAP_SIZE];
};

/* 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 MASK(p)         ((char*)OPERAND(p))
#define STR_LEN(p)      (((struct regnode_string *)p)->str_len)
#define STRING(p)       (((struct regnode_string *)p)->string)
#define STR_SZ(l)       ((l + sizeof(regnode) - 1) / sizeof(regnode))
#define NODE_SZ_STR(p)  (STR_SZ(STR_LEN(p))+1)

#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 REG_MAGIC 0234

#define SIZE_ONLY (PL_regcode == &PL_regdummy)

/* Flags for node->flags of ANYOF */

#define ANYOF_CLASS     0x08
#define ANYOF_INVERT    0x04
#define ANYOF_FOLD      0x02
#define ANYOF_LOCALE    0x01

/* Used for regstclass only */
#define ANYOF_EOS       0x10            /* Can match an empty string too */

/* Character classes for node->classflags of ANYOF */
/* Should be synchronized with a table in regprop() */
/* 2n should pair with 2n+1 */

#define ANYOF_ALNUM      0      /* \w, utf8::IsWord, isALNUM() */
#define ANYOF_NALNUM     1
#define ANYOF_SPACE      2
#define ANYOF_NSPACE     3
#define ANYOF_DIGIT      4
#define ANYOF_NDIGIT     5
#define ANYOF_ALNUMC     6      /* isalnum(3), utf8::IsAlnum, isALNUMC() */
#define ANYOF_NALNUMC    7
#define ANYOF_ALPHA      8
#define ANYOF_NALPHA     9
#define ANYOF_ASCII     10
#define ANYOF_NASCII    11
#define ANYOF_CNTRL     12
#define ANYOF_NCNTRL    13
#define ANYOF_GRAPH     14
#define ANYOF_NGRAPH    15
#define ANYOF_LOWER     16
#define ANYOF_NLOWER    17
#define ANYOF_PRINT     18
#define ANYOF_NPRINT    19
#define ANYOF_PUNCT     20
#define ANYOF_NPUNCT    21
#define ANYOF_UPPER     22
#define ANYOF_NUPPER    23
#define ANYOF_XDIGIT    24
#define ANYOF_NXDIGIT   25

#define ANYOF_MAX       31

/* Backward source code compatibility. */

#define ANYOF_ALNUML     ANYOF_ALNUM
#define ANYOF_NALNUML    ANYOF_NALNUM
#define ANYOF_SPACEL     ANYOF_SPACE
#define ANYOF_NSPACEL    ANYOF_NSPACE

/* Utility macros for the bitmap and classes of ANYOF */

#define ANYOF_SIZE              (sizeof(struct regnode_charclass))
#define ANYOF_CLASS_SIZE        (sizeof(struct regnode_charclass_class))

#define ANYOF_FLAGS(p)          ((p)->flags)
#define ANYOF_FLAGS_ALL         0xff

#define ANYOF_BIT(c)            (1 << ((c) & 7))

#define ANYOF_CLASS_BYTE(p, c)  (((struct regnode_charclass_class*)(p))->classflags[((c) >> 3) & 3])
#define ANYOF_CLASS_SET(p, c)   (ANYOF_CLASS_BYTE(p, c) |=  ANYOF_BIT(c))
#define ANYOF_CLASS_CLEAR(p, c) (ANYOF_CLASS_BYTE(p, c) &= ~ANYOF_BIT(c))
#define ANYOF_CLASS_TEST(p, c)  (ANYOF_CLASS_BYTE(p, c) &   ANYOF_BIT(c))

#define ANYOF_CLASS_ZERO(ret)   Zero(((struct regnode_charclass_class*)(ret))->classflags, ANYOF_CLASSBITMAP_SIZE, char)
#define ANYOF_BITMAP_ZERO(ret)  Zero(((struct regnode_charclass*)(ret))->bitmap, ANYOF_BITMAP_SIZE, char)

#define ANYOF_BITMAP(p)         (((struct regnode_charclass*)(p))->bitmap)
#define ANYOF_BITMAP_BYTE(p, c) (ANYOF_BITMAP(p)[((c) >> 3) & 31])
#define ANYOF_BITMAP_SET(p, c)  (ANYOF_BITMAP_BYTE(p, c) |=  ANYOF_BIT(c))
#define ANYOF_BITMAP_CLEAR(p,c) (ANYOF_BITMAP_BYTE(p, c) &= ~ANYOF_BIT(c))
#define ANYOF_BITMAP_TEST(p, c) (ANYOF_BITMAP_BYTE(p, c) &   ANYOF_BIT(c))

#define ANYOF_SKIP              ((ANYOF_SIZE - 1)/sizeof(regnode))
#define ANYOF_CLASS_SKIP        ((ANYOF_CLASS_SIZE - 1)/sizeof(regnode))
#define ANYOF_CLASS_ADD_SKIP    (ANYOF_CLASS_SKIP - ANYOF_SKIP)

/*
 * Utility definitions.
 */
#ifndef lint
#ifndef CHARMASK
#define UCHARAT(p)      ((int)*(U8*)(p))
#else
#define UCHARAT(p)      ((int)*(p)&CHARMASK)
#endif
#else /* lint */
#define UCHARAT(p)      PL_regdummy
#endif /* lint */

#define FAIL(m) \
    STMT_START {                                                        \
        if (!SIZE_ONLY)                                                 \
            SAVEDESTRUCTOR_X(clear_re,(void*)PL_regcomp_rx);            \
        Perl_croak(aTHX_ "/%.127s/: %s",  PL_regprecomp,m);             \
    } STMT_END

#define FAIL2(pat,m) \
    STMT_START {                                                        \
        if (!SIZE_ONLY)                                                 \
            SAVEDESTRUCTOR_X(clear_re,(void*)PL_regcomp_rx);            \
        S_re_croak2(aTHX_ "/%.127s/: ",pat,PL_regprecomp,m);            \
    } STMT_END

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

#define REG_SEEN_ZERO_LEN       1
#define REG_SEEN_LOOKBEHIND     2
#define REG_SEEN_GPOS           4
#define REG_SEEN_EVAL           8

START_EXTERN_C

#include "regnodes.h"

/* The following have no fixed length. U8 so we can do strchr() on it. */
#ifndef DOINIT
EXTCONST U8 PL_varies[];
#else
EXTCONST U8 PL_varies[] = {
    BRANCH, BACK, STAR, PLUS, CURLY, CURLYX, REF, REFF, REFFL, 
    WHILEM, CURLYM, CURLYN, BRANCHJ, IFTHEN, SUSPEND, CLUMP, 0
};
#endif

/* The following always have a length of 1. U8 we can do strchr() on it. */
/* (Note that length 1 means "one character" under UTF8, not "one octet".) */
#ifndef DOINIT
EXTCONST U8 PL_simple[];
#else
EXTCONST U8 PL_simple[] = {
    REG_ANY, ANYUTF8, SANY, SANYUTF8, ANYOF, ANYOFUTF8,
    ALNUM, ALNUMUTF8, ALNUML, ALNUMLUTF8,
    NALNUM, NALNUMUTF8, NALNUML, NALNUMLUTF8,
    SPACE, SPACEUTF8, SPACEL, SPACELUTF8,
    NSPACE, NSPACEUTF8, NSPACEL, NSPACELUTF8,
    DIGIT, DIGITUTF8, NDIGIT, NDIGITUTF8, 0
};
#endif

END_EXTERN_C

typedef struct re_scream_pos_data_s
{
    char **scream_olds;         /* match pos */
    I32 *scream_pos;            /* Internal iterator of scream. */
} re_scream_pos_data;

struct reg_data {
    U32 count;
    U8 *what;
    void* data[1];
};

struct reg_substr_datum {
    I32 min_offset;
    I32 max_offset;
    SV *substr;
};

struct reg_substr_data {
    struct reg_substr_datum data[3];    /* Actual array */
};

#define anchored_substr substrs->data[0].substr
#define anchored_offset substrs->data[0].min_offset
#define float_substr substrs->data[1].substr
#define float_min_offset substrs->data[1].min_offset
#define float_max_offset substrs->data[1].max_offset
#define check_substr substrs->data[2].substr
#define check_offset_min substrs->data[2].min_offset
#define check_offset_max substrs->data[2].max_offset