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Put back the cygwin32 Configure fix of 3582 undone by 3597.
[perl5.git] / regcomp.h
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a0d0e21e 1/* regcomp.h
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2 */
3
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4typedef OP OP_4tree; /* Will be redefined later. */
5
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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
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12 * reganch is the match anchored (at beginning-of-line only)?
13 * regmust string (pointer into program) that match must include, or NULL
79072805 14 * [regmust changed to SV* for bminstr()--law]
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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
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22 * potentially expensive (at present, the only such thing detected is * or +
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
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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
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52/*
53 * A node is one char of opcode followed by two chars of "next" pointer.
54 * "Next" pointers are stored as two 8-bit pieces, high order first. The
55 * value is a positive offset from the opcode of the node containing it.
56 * An operand, if any, simply follows the node. (Note that much of the
57 * code generation knows about this implicit relationship.)
58 *
59 * Using two bytes for the "next" pointer is vast overkill for most things,
60 * but allows patterns to get big without disasters.
61 *
e91177ed 62 * [The "next" pointer is always aligned on an even
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63 * boundary, and reads the offset directly as a short. Also, there is no
64 * special test to reverse the sign of BACK pointers since the offset is
65 * stored negative.]
66 */
67
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68struct regnode_string {
69 U8 flags;
70 U8 type;
71 U16 next_off;
72 U8 string[1];
73};
a687059c 74
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75struct regnode_1 {
76 U8 flags;
77 U8 type;
78 U16 next_off;
79 U32 arg1;
80};
81
82struct regnode_2 {
83 U8 flags;
84 U8 type;
85 U16 next_off;
86 U16 arg1;
87 U16 arg2;
88};
89
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90/* XXX fix this description.
91 Impose a limit of REG_INFTY on various pattern matching operations
92 to limit stack growth and to avoid "infinite" recursions.
93*/
94/* The default size for REG_INFTY is I16_MAX, which is the same as
95 SHORT_MAX (see perl.h). Unfortunately I16 isn't necessarily 16 bits
96 (see handy.h). On the Cray C90, sizeof(short)==4 and hence I16_MAX is
97 ((1<<31)-1), while on the Cray T90, sizeof(short)==8 and I16_MAX is
98 ((1<<63)-1). To limit stack growth to reasonable sizes, supply a
99 smaller default.
100 --Andy Dougherty 11 June 1998
101*/
102#if SHORTSIZE > 2
103# ifndef REG_INFTY
104# define REG_INFTY ((1<<15)-1)
105# endif
106#endif
107
108#ifndef REG_INFTY
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109# define REG_INFTY I16_MAX
110#endif
a687059c 111
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112#define ARG_VALUE(arg) (arg)
113#define ARG__SET(arg,val) ((arg) = (val))
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114
115#define ARG(p) ARG_VALUE(ARG_LOC(p))
116#define ARG1(p) ARG_VALUE(ARG1_LOC(p))
117#define ARG2(p) ARG_VALUE(ARG2_LOC(p))
118#define ARG_SET(p, val) ARG__SET(ARG_LOC(p), (val))
119#define ARG1_SET(p, val) ARG__SET(ARG1_LOC(p), (val))
120#define ARG2_SET(p, val) ARG__SET(ARG2_LOC(p), (val))
121
122#ifndef lint
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123# define NEXT_OFF(p) ((p)->next_off)
124# define NODE_ALIGN(node)
125# define NODE_ALIGN_FILL(node) ((node)->flags = 0xde) /* deadbeef */
a687059c 126#else /* lint */
c277df42 127# define NEXT_OFF(p) 0
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128# define NODE_ALIGN(node)
129# define NODE_ALIGN_FILL(node)
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130#endif /* lint */
131
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132#define SIZE_ALIGN NODE_ALIGN
133
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134#define OP(p) ((p)->type)
135#define OPERAND(p) (((struct regnode_string *)p)->string)
136#define NODE_ALIGN(node)
137#define ARG_LOC(p) (((struct regnode_1 *)p)->arg1)
138#define ARG1_LOC(p) (((struct regnode_2 *)p)->arg1)
139#define ARG2_LOC(p) (((struct regnode_2 *)p)->arg2)
140#define NODE_STEP_REGNODE 1 /* sizeof(regnode)/sizeof(regnode) */
141#define EXTRA_STEP_2ARGS EXTRA_SIZE(struct regnode_2)
142
143#define NODE_STEP_B 4
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144
145#define NEXTOPER(p) ((p) + NODE_STEP_REGNODE)
146#define PREVOPER(p) ((p) - NODE_STEP_REGNODE)
147
e91177ed 148#define FILL_ADVANCE_NODE(ptr, op) STMT_START { \
c277df42 149 (ptr)->type = op; (ptr)->next_off = 0; (ptr)++; } STMT_END
e91177ed 150#define FILL_ADVANCE_NODE_ARG(ptr, op, arg) STMT_START { \
c277df42 151 ARG_SET(ptr, arg); FILL_ADVANCE_NODE(ptr, op); (ptr) += 1; } STMT_END
a687059c 152
22c35a8c 153#define REG_MAGIC 0234
a687059c 154
3280af22 155#define SIZE_ONLY (PL_regcode == &PL_regdummy)
c277df42 156
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157/* Flags for first parameter byte of ANYOF */
158#define ANYOF_INVERT 0x40
159#define ANYOF_FOLD 0x20
160#define ANYOF_LOCALE 0x10
161#define ANYOF_ISA 0x0F
162#define ANYOF_ALNUML 0x08
163#define ANYOF_NALNUML 0x04
164#define ANYOF_SPACEL 0x02
165#define ANYOF_NSPACEL 0x01
166
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167/* Utility macros for bitmap of ANYOF */
168#define ANYOF_BYTE(p,c) (p)[1 + (((c) >> 3) & 31)]
169#define ANYOF_BIT(c) (1 << ((c) & 7))
170#define ANYOF_SET(p,c) (ANYOF_BYTE(p,c) |= ANYOF_BIT(c))
171#define ANYOF_CLEAR(p,c) (ANYOF_BYTE(p,c) &= ~ANYOF_BIT(c))
172#define ANYOF_TEST(p,c) (ANYOF_BYTE(p,c) & ANYOF_BIT(c))
173
c277df42 174#define ANY_SKIP ((33 - 1)/sizeof(regnode) + 1)
c277df42 175
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176/*
177 * Utility definitions.
178 */
179#ifndef lint
2304df62 180#ifndef CHARMASK
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181#define UCHARAT(p) ((int)*(unsigned char *)(p))
182#else
2304df62 183#define UCHARAT(p) ((int)*(p)&CHARMASK)
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184#endif
185#else /* lint */
6b88bc9c 186#define UCHARAT(p) PL_regdummy
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187#endif /* lint */
188
34184a49 189#define FAIL(m) \
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190 STMT_START { \
191 if (!SIZE_ONLY) \
192 SAVEDESTRUCTOR(S_clear_re,(void*)PL_regcomp_rx); \
193 Perl_croak(aTHX_ "/%.127s/: %s", PL_regprecomp,m); \
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194 } STMT_END
195
196#define FAIL2(pat,m) \
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197 STMT_START { \
198 if (!SIZE_ONLY) \
199 SAVEDESTRUCTOR(S_clear_re,(void*)PL_regcomp_rx); \
200 S_re_croak2(aTHX_ "/%.127s/: ",pat,PL_regprecomp,m); \
34184a49 201 } STMT_END
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202
203#define EXTRA_SIZE(guy) ((sizeof(guy)-1)/sizeof(struct regnode))
204
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205#define REG_SEEN_ZERO_LEN 1
206#define REG_SEEN_LOOKBEHIND 2
207#define REG_SEEN_GPOS 4
208#define REG_SEEN_EVAL 8
209
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210START_EXTERN_C
211
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212#include "regnodes.h"
213
214/* The following have no fixed length. char* since we do strchr on it. */
215#ifndef DOINIT
22c35a8c 216EXTCONST char PL_varies[];
d09b2d29 217#else
22c35a8c 218EXTCONST char PL_varies[] = {
d09b2d29 219 BRANCH, BACK, STAR, PLUS, CURLY, CURLYX, REF, REFF, REFFL,
a0ed51b3 220 WHILEM, CURLYM, CURLYN, BRANCHJ, IFTHEN, SUSPEND, CLUMP, 0
c277df42 221};
d09b2d29 222#endif
c277df42 223
d09b2d29 224/* The following always have a length of 1. char* since we do strchr on it. */
a0ed51b3 225/* (Note that lenght 1 means "one character" under UTF8, not "one octet".) */
d09b2d29 226#ifndef DOINIT
22c35a8c 227EXTCONST char PL_simple[];
d09b2d29 228#else
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229EXTCONST char PL_simple[] = {
230 REG_ANY, ANYUTF8, SANY, SANYUTF8, ANYOF, ANYOFUTF8,
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231 ALNUM, ALNUMUTF8, ALNUML, ALNUMLUTF8,
232 NALNUM, NALNUMUTF8, NALNUML, NALNUMLUTF8,
233 SPACE, SPACEUTF8, SPACEL, SPACELUTF8,
234 NSPACE, NSPACEUTF8, NSPACEL, NSPACELUTF8,
235 DIGIT, DIGITUTF8, NDIGIT, NDIGITUTF8, 0
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236};
237#endif
238
73c4f7a1 239END_EXTERN_C