1/*
2 * Copyright (c) 2015, Intel Corporation
3 *
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6 *
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15 *
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17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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27 */
28
29/** \file
30 * \brief Boundary assertions (^, $, \\A, \\Z, \\z)
31 */
32
33
34#include "ComponentBoundary.h"
35
36#include "buildstate.h"
37#include "parse_error.h"
38#include "position.h"
39#include "position_info.h"
40#include "Parser.h"
41#include "util/charreach.h"
42#include "nfagraph/ng_builder.h"
43
44#include <cassert>
45
46using namespace std;
47
48namespace ue2 {
49
50ComponentBoundary::ComponentBoundary(enum Boundary bound)
51 : m_bound(bound), m_newline(GlushkovBuildState::POS_UNINITIALIZED) {}
52
53ComponentBoundary::~ComponentBoundary() {
54}
55
56ComponentBoundary::ComponentBoundary(const ComponentBoundary &other)
57 : Component(other), m_bound(other.m_bound), m_newline(other.m_newline),
58 m_first(other.m_first), m_last(other.m_last) {}
59
60ComponentBoundary * ComponentBoundary::clone() const {
61 return new ComponentBoundary(*this);
62}
63
64vector<PositionInfo> ComponentBoundary::first() const {
65 return m_first;
66}
67
68vector<PositionInfo> ComponentBoundary::last() const {
69 return m_last;
70}
71
72bool ComponentBoundary::empty() const {
73 return true;
74}
75
76bool ComponentBoundary::repeatable() const {
77 return false;
78}
79
80static
81Position makeNewline(GlushkovBuildState &bs) {
82 NFABuilder &builder = bs.getBuilder();
83 Position newline = builder.makePositions(1);
84 builder.addCharReach(newline, CharReach('\n'));
85 return newline;
86}
87
88void ComponentBoundary::notePositions(GlushkovBuildState & bs) {
89 NFABuilder &builder = bs.getBuilder();
90 const Position startState = builder.getStart();
91
92 switch (m_bound) {
93 case BEGIN_STRING: // beginning of data stream ('^')
94 {
95 PositionInfo epsilon(GlushkovBuildState::POS_EPSILON);
96 epsilon.flags = POS_FLAG_NOFLOAT;
97 m_first.push_back(epsilon);
98
99 // We have the start vertex in firsts so that we can discourage
100 // the mid-pattern use of boundaries.
101 m_first.push_back(startState);
102
103 break;
104 }
105 case BEGIN_LINE: // multiline anchor: beginning of stream or a newline
106 {
107 PositionInfo epsilon(GlushkovBuildState::POS_EPSILON);
108 epsilon.flags = POS_FLAG_NOFLOAT;
109 m_first.push_back(epsilon);
110
111 // We have the start vertex in firsts so that we can discourage
112 // the mid-pattern use of boundaries.
113 m_first.push_back(startState);
114
115 // Newline
116 m_newline = makeNewline(bs);
117 builder.setAssertFlag(m_newline, POS_FLAG_MULTILINE_START);
118 builder.setAssertFlag(m_newline, POS_FLAG_VIRTUAL_START);
119 PositionInfo nl(m_newline);
120 nl.flags = POS_FLAG_MUST_FLOAT | POS_FLAG_FIDDLE_ACCEPT;
121 m_first.push_back(nl);
122 m_last.push_back(nl);
123 recordPosBounds(m_newline, m_newline + 1);
124 break;
125 }
126 case END_STRING: // end of data stream ('\z')
127 {
128 PositionInfo epsilon(GlushkovBuildState::POS_EPSILON);
129 epsilon.flags = POS_FLAG_WIRE_EOD | POS_FLAG_NO_NL_EOD |
130 POS_FLAG_NO_NL_ACCEPT | POS_FLAG_ONLY_ENDS;
131 m_first.push_back(epsilon);
132 break;
133 }
134 case END_STRING_OPTIONAL_LF: // end of data with optional LF ('$')
135 {
136 PositionInfo epsilon(GlushkovBuildState::POS_EPSILON);
137 epsilon.flags = POS_FLAG_WIRE_EOD | POS_FLAG_WIRE_NL_EOD |
138 POS_FLAG_NO_NL_ACCEPT | POS_FLAG_ONLY_ENDS;
139 m_first.push_back(epsilon);
140 break;
141 }
142 case END_LINE: // multiline anchor: end of data or a newline
143 {
144 PositionInfo epsilon(GlushkovBuildState::POS_EPSILON);
145 epsilon.flags = POS_FLAG_WIRE_EOD | POS_FLAG_WIRE_NL_EOD |
146 POS_FLAG_WIRE_NL_ACCEPT | POS_FLAG_ONLY_ENDS;
147 m_first.push_back(epsilon);
148 break;
149 }
150 default:
151 // unsupported
152 assert(0);
153 break;
154 }
155}
156
157void ComponentBoundary::buildFollowSet(GlushkovBuildState &,
158 const vector<PositionInfo> &) {
159
160}
161
162bool ComponentBoundary::checkEmbeddedStartAnchor(bool at_start) const {
163 if (at_start) {
164 return at_start;
165 }
166
167 if (m_bound == BEGIN_STRING || m_bound == BEGIN_LINE) {
168 throw ParseError("Embedded start anchors not supported.");
169 }
170
171 return at_start;
172}
173
174bool ComponentBoundary::checkEmbeddedEndAnchor(bool at_end) const {
175 if (at_end) {
176 return at_end;
177 }
178
179 if (m_bound != BEGIN_STRING && m_bound != BEGIN_LINE) {
180 throw ParseError("Embedded end anchors not supported.");
181 }
182
183 return at_end;
184}
185
186} // namespace
187