1 /*    invlist_inline.h
2  *
3  *    Copyright (C) 2012 by Larry Wall and others
4  *
5  *    You may distribute under the terms of either the GNU General Public
6  *    License or the Artistic License, as specified in the README file.
7  */
8 
9 #ifndef PERL_INVLIST_INLINE_H_
10 #define PERL_INVLIST_INLINE_H_
11 
12 #if defined(PERL_IN_UTF8_C)             \
13  || defined(PERL_IN_REGCOMP_C)          \
14  || defined(PERL_IN_REGEXEC_C)          \
15  || defined(PERL_IN_TOKE_C)             \
16  || defined(PERL_IN_PP_C)               \
17  || defined(PERL_IN_OP_C)               \
18  || defined(PERL_IN_DOOP_C)
19 
20 /* An element is in an inversion list iff its index is even numbered: 0, 2, 4,
21  * etc */
22 #define ELEMENT_RANGE_MATCHES_INVLIST(i) (! ((i) & 1))
23 #define PREV_RANGE_MATCHES_INVLIST(i) (! ELEMENT_RANGE_MATCHES_INVLIST(i))
24 
25 /* This converts to/from our UVs to what the SV code is expecting: bytes. */
26 #define TO_INTERNAL_SIZE(x) ((x) * sizeof(UV))
27 #define FROM_INTERNAL_SIZE(x) ((x)/ sizeof(UV))
28 
29 PERL_STATIC_INLINE bool
S_is_invlist(SV * const invlist)30 S_is_invlist(SV* const invlist)
31 {
32     return invlist != NULL && SvTYPE(invlist) == SVt_INVLIST;
33 }
34 
35 PERL_STATIC_INLINE bool*
S_get_invlist_offset_addr(SV * invlist)36 S_get_invlist_offset_addr(SV* invlist)
37 {
38     /* Return the address of the field that says whether the inversion list is
39      * offset (it contains 1) or not (contains 0) */
40     PERL_ARGS_ASSERT_GET_INVLIST_OFFSET_ADDR;
41 
42     assert(is_invlist(invlist));
43 
44     return &(((XINVLIST*) SvANY(invlist))->is_offset);
45 }
46 
47 PERL_STATIC_INLINE UV
S__invlist_len(SV * const invlist)48 S__invlist_len(SV* const invlist)
49 {
50     /* Returns the current number of elements stored in the inversion list's
51      * array */
52 
53     PERL_ARGS_ASSERT__INVLIST_LEN;
54 
55     assert(is_invlist(invlist));
56 
57     return (SvCUR(invlist) == 0)
58            ? 0
59            : FROM_INTERNAL_SIZE(SvCUR(invlist)) - *get_invlist_offset_addr(invlist);
60 }
61 
62 PERL_STATIC_INLINE bool
S__invlist_contains_cp(SV * const invlist,const UV cp)63 S__invlist_contains_cp(SV* const invlist, const UV cp)
64 {
65     /* Does <invlist> contain code point <cp> as part of the set? */
66 
67     IV index = _invlist_search(invlist, cp);
68 
69     PERL_ARGS_ASSERT__INVLIST_CONTAINS_CP;
70 
71     return index >= 0 && ELEMENT_RANGE_MATCHES_INVLIST(index);
72 }
73 
74 PERL_STATIC_INLINE UV*
S_invlist_array(SV * const invlist)75 S_invlist_array(SV* const invlist)
76 {
77     /* Returns the pointer to the inversion list's array.  Every time the
78      * length changes, this needs to be called in case malloc or realloc moved
79      * it */
80 
81     PERL_ARGS_ASSERT_INVLIST_ARRAY;
82 
83     /* Must not be empty.  If these fail, you probably didn't check for <len>
84      * being non-zero before trying to get the array */
85     assert(_invlist_len(invlist));
86 
87     /* The very first element always contains zero, The array begins either
88      * there, or if the inversion list is offset, at the element after it.
89      * The offset header field determines which; it contains 0 or 1 to indicate
90      * how much additionally to add */
91     assert(0 == *(SvPVX(invlist)));
92     return ((UV *) SvPVX(invlist) + *get_invlist_offset_addr(invlist));
93 }
94 
95 #endif
96 #if defined(PERL_IN_REGCOMP_C) || defined(PERL_IN_OP_C) || defined(PERL_IN_DOOP_C)
97 
98 PERL_STATIC_INLINE void
S_invlist_extend(pTHX_ SV * const invlist,const UV new_max)99 S_invlist_extend(pTHX_ SV* const invlist, const UV new_max)
100 {
101     /* Grow the maximum size of an inversion list */
102 
103     PERL_ARGS_ASSERT_INVLIST_EXTEND;
104 
105     assert(SvTYPE(invlist) == SVt_INVLIST);
106 
107     /* Add one to account for the zero element at the beginning which may not
108      * be counted by the calling parameters */
109     SvGROW((SV *)invlist, TO_INTERNAL_SIZE(new_max + 1));
110 }
111 
112 PERL_STATIC_INLINE void
S_invlist_set_len(pTHX_ SV * const invlist,const UV len,const bool offset)113 S_invlist_set_len(pTHX_ SV* const invlist, const UV len, const bool offset)
114 {
115     /* Sets the current number of elements stored in the inversion list.
116      * Updates SvCUR correspondingly */
117     PERL_UNUSED_CONTEXT;
118     PERL_ARGS_ASSERT_INVLIST_SET_LEN;
119 
120     assert(SvTYPE(invlist) == SVt_INVLIST);
121 
122     SvCUR_set(invlist,
123               (len == 0)
124                ? 0
125                : TO_INTERNAL_SIZE(len + offset));
126     assert(SvLEN(invlist) == 0 || SvCUR(invlist) <= SvLEN(invlist));
127 }
128 
129 PERL_STATIC_INLINE SV*
S_add_cp_to_invlist(pTHX_ SV * invlist,const UV cp)130 S_add_cp_to_invlist(pTHX_ SV* invlist, const UV cp) {
131     return _add_range_to_invlist(invlist, cp, cp);
132 }
133 
134 PERL_STATIC_INLINE UV
S_invlist_highest(SV * const invlist)135 S_invlist_highest(SV* const invlist)
136 {
137     /* Returns the highest code point that matches an inversion list.  This API
138      * has an ambiguity, as it returns 0 under either the highest is actually
139      * 0, or if the list is empty.  If this distinction matters to you, check
140      * for emptiness before calling this function */
141 
142     UV len = _invlist_len(invlist);
143     UV *array;
144 
145     PERL_ARGS_ASSERT_INVLIST_HIGHEST;
146 
147     if (len == 0) {
148 	return 0;
149     }
150 
151     array = invlist_array(invlist);
152 
153     /* The last element in the array in the inversion list always starts a
154      * range that goes to infinity.  That range may be for code points that are
155      * matched in the inversion list, or it may be for ones that aren't
156      * matched.  In the latter case, the highest code point in the set is one
157      * less than the beginning of this range; otherwise it is the final element
158      * of this range: infinity */
159     return (ELEMENT_RANGE_MATCHES_INVLIST(len - 1))
160            ? UV_MAX
161            : array[len - 1] - 1;
162 }
163 
164 #endif
165 #if defined(PERL_IN_REGCOMP_C) || defined(PERL_IN_OP_C)
166 
167 PERL_STATIC_INLINE STRLEN*
S_get_invlist_iter_addr(SV * invlist)168 S_get_invlist_iter_addr(SV* invlist)
169 {
170     /* Return the address of the UV that contains the current iteration
171      * position */
172 
173     PERL_ARGS_ASSERT_GET_INVLIST_ITER_ADDR;
174 
175     assert(is_invlist(invlist));
176 
177     return &(((XINVLIST*) SvANY(invlist))->iterator);
178 }
179 
180 PERL_STATIC_INLINE void
S_invlist_iterinit(SV * invlist)181 S_invlist_iterinit(SV* invlist)	/* Initialize iterator for invlist */
182 {
183     PERL_ARGS_ASSERT_INVLIST_ITERINIT;
184 
185     *get_invlist_iter_addr(invlist) = 0;
186 }
187 
188 PERL_STATIC_INLINE void
S_invlist_iterfinish(SV * invlist)189 S_invlist_iterfinish(SV* invlist)
190 {
191     /* Terminate iterator for invlist.  This is to catch development errors.
192      * Any iteration that is interrupted before completed should call this
193      * function.  Functions that add code points anywhere else but to the end
194      * of an inversion list assert that they are not in the middle of an
195      * iteration.  If they were, the addition would make the iteration
196      * problematical: if the iteration hadn't reached the place where things
197      * were being added, it would be ok */
198 
199     PERL_ARGS_ASSERT_INVLIST_ITERFINISH;
200 
201     *get_invlist_iter_addr(invlist) = (STRLEN) UV_MAX;
202 }
203 
204 STATIC bool
S_invlist_iternext(SV * invlist,UV * start,UV * end)205 S_invlist_iternext(SV* invlist, UV* start, UV* end)
206 {
207     /* An C<invlist_iterinit> call on <invlist> must be used to set this up.
208      * This call sets in <*start> and <*end>, the next range in <invlist>.
209      * Returns <TRUE> if successful and the next call will return the next
210      * range; <FALSE> if was already at the end of the list.  If the latter,
211      * <*start> and <*end> are unchanged, and the next call to this function
212      * will start over at the beginning of the list */
213 
214     STRLEN* pos = get_invlist_iter_addr(invlist);
215     UV len = _invlist_len(invlist);
216     UV *array;
217 
218     PERL_ARGS_ASSERT_INVLIST_ITERNEXT;
219 
220     if (*pos >= len) {
221 	*pos = (STRLEN) UV_MAX;	/* Force iterinit() to be required next time */
222 	return FALSE;
223     }
224 
225     array = invlist_array(invlist);
226 
227     *start = array[(*pos)++];
228 
229     if (*pos >= len) {
230 	*end = UV_MAX;
231     }
232     else {
233 	*end = array[(*pos)++] - 1;
234     }
235 
236     return TRUE;
237 }
238 
239 #endif
240 
241 #ifndef PERL_IN_REGCOMP_C
242 
243 /* These symbols are only needed later in regcomp.c */
244 #       undef TO_INTERNAL_SIZE
245 #       undef FROM_INTERNAL_SIZE
246 #endif
247 
248 #endif /* PERL_INVLIST_INLINE_H_ */
249