1 |
|
/****************************************************************************** |
2 |
|
* Top contributors (to current version): |
3 |
|
* Andrew Reynolds |
4 |
|
* |
5 |
|
* This file is part of the cvc5 project. |
6 |
|
* |
7 |
|
* Copyright (c) 2009-2021 by the authors listed in the file AUTHORS |
8 |
|
* in the top-level source directory and their institutional affiliations. |
9 |
|
* All rights reserved. See the file COPYING in the top-level source |
10 |
|
* directory for licensing information. |
11 |
|
* **************************************************************************** |
12 |
|
* |
13 |
|
* Rewrite database |
14 |
|
*/ |
15 |
|
|
16 |
|
#include "expr/nary_term_util.h" |
17 |
|
|
18 |
|
#include "expr/attribute.h" |
19 |
|
#include "theory/bv/theory_bv_utils.h" |
20 |
|
#include "theory/strings/word.h" |
21 |
|
#include "util/bitvector.h" |
22 |
|
#include "util/rational.h" |
23 |
|
#include "util/regexp.h" |
24 |
|
#include "util/string.h" |
25 |
|
|
26 |
|
using namespace cvc5::kind; |
27 |
|
|
28 |
|
namespace cvc5 { |
29 |
|
namespace expr { |
30 |
|
|
31 |
|
struct IsListTag |
32 |
|
{ |
33 |
|
}; |
34 |
|
using IsListAttr = expr::Attribute<IsListTag, bool>; |
35 |
|
|
36 |
|
void markListVar(TNode fv) |
37 |
|
{ |
38 |
|
Assert(fv.getKind() == BOUND_VARIABLE); |
39 |
|
fv.setAttribute(IsListAttr(), true); |
40 |
|
} |
41 |
|
|
42 |
|
bool isListVar(TNode fv) { return fv.getAttribute(IsListAttr()); } |
43 |
|
|
44 |
|
bool hasListVar(TNode n) |
45 |
|
{ |
46 |
|
std::unordered_set<TNode> visited; |
47 |
|
std::unordered_set<TNode>::iterator it; |
48 |
|
std::vector<TNode> visit; |
49 |
|
TNode cur; |
50 |
|
visit.push_back(n); |
51 |
|
do |
52 |
|
{ |
53 |
|
cur = visit.back(); |
54 |
|
visit.pop_back(); |
55 |
|
it = visited.find(cur); |
56 |
|
|
57 |
|
if (it == visited.end()) |
58 |
|
{ |
59 |
|
visited.insert(cur); |
60 |
|
if (isListVar(cur)) |
61 |
|
{ |
62 |
|
return true; |
63 |
|
} |
64 |
|
visit.insert(visit.end(), cur.begin(), cur.end()); |
65 |
|
} |
66 |
|
} while (!visit.empty()); |
67 |
|
return false; |
68 |
|
} |
69 |
|
|
70 |
|
bool getListVarContext(TNode n, std::map<Node, Kind>& context) |
71 |
|
{ |
72 |
|
std::unordered_set<TNode> visited; |
73 |
|
std::unordered_set<TNode>::iterator it; |
74 |
|
std::map<Node, Kind>::iterator itc; |
75 |
|
std::vector<TNode> visit; |
76 |
|
TNode cur; |
77 |
|
visit.push_back(n); |
78 |
|
do |
79 |
|
{ |
80 |
|
cur = visit.back(); |
81 |
|
visit.pop_back(); |
82 |
|
it = visited.find(cur); |
83 |
|
if (it == visited.end()) |
84 |
|
{ |
85 |
|
visited.insert(cur); |
86 |
|
if (isListVar(cur)) |
87 |
|
{ |
88 |
|
// top-level list variable, undefined |
89 |
|
return false; |
90 |
|
} |
91 |
|
for (const Node& cn : cur) |
92 |
|
{ |
93 |
|
if (isListVar(cn)) |
94 |
|
{ |
95 |
|
itc = context.find(cn); |
96 |
|
if (itc == context.end()) |
97 |
|
{ |
98 |
|
context[cn] = cur.getKind(); |
99 |
|
} |
100 |
|
else if (itc->second != cur.getKind()) |
101 |
|
{ |
102 |
|
return false; |
103 |
|
} |
104 |
|
continue; |
105 |
|
} |
106 |
|
visit.push_back(cn); |
107 |
|
} |
108 |
|
} |
109 |
|
} while (!visit.empty()); |
110 |
|
return true; |
111 |
|
} |
112 |
|
|
113 |
|
Node getNullTerminator(Kind k, TypeNode tn) |
114 |
|
{ |
115 |
|
NodeManager* nm = NodeManager::currentNM(); |
116 |
|
Node nullTerm; |
117 |
|
switch (k) |
118 |
|
{ |
119 |
|
case OR: nullTerm = nm->mkConst(false); break; |
120 |
|
case AND: |
121 |
|
case SEP_STAR: nullTerm = nm->mkConst(true); break; |
122 |
|
case PLUS: nullTerm = nm->mkConst(Rational(0)); break; |
123 |
|
case MULT: |
124 |
|
case NONLINEAR_MULT: nullTerm = nm->mkConst(Rational(1)); break; |
125 |
|
case STRING_CONCAT: |
126 |
|
// handles strings and sequences |
127 |
|
nullTerm = theory::strings::Word::mkEmptyWord(tn); |
128 |
|
break; |
129 |
|
case REGEXP_CONCAT: |
130 |
|
// the language containing only the empty string |
131 |
|
nullTerm = nm->mkNode(STRING_TO_REGEXP, nm->mkConst(String(""))); |
132 |
|
break; |
133 |
|
case BITVECTOR_AND: |
134 |
|
nullTerm = theory::bv::utils::mkOnes(tn.getBitVectorSize()); |
135 |
|
break; |
136 |
|
case BITVECTOR_OR: |
137 |
|
case BITVECTOR_ADD: |
138 |
|
case BITVECTOR_XOR: |
139 |
|
nullTerm = theory::bv::utils::mkZero(tn.getBitVectorSize()); |
140 |
|
break; |
141 |
|
case BITVECTOR_MULT: |
142 |
|
nullTerm = theory::bv::utils::mkOne(tn.getBitVectorSize()); |
143 |
|
break; |
144 |
|
default: |
145 |
|
// not handled as null-terminated |
146 |
|
break; |
147 |
|
} |
148 |
|
return nullTerm; |
149 |
|
} |
150 |
|
|
151 |
|
Node narySubstitute(Node src, |
152 |
|
const std::vector<Node>& vars, |
153 |
|
const std::vector<Node>& subs) |
154 |
|
{ |
155 |
|
// assumes all variables are list variables |
156 |
|
NodeManager* nm = NodeManager::currentNM(); |
157 |
|
std::unordered_map<TNode, Node> visited; |
158 |
|
std::unordered_map<TNode, Node>::iterator it; |
159 |
|
std::vector<TNode> visit; |
160 |
|
std::vector<Node>::const_iterator itv; |
161 |
|
TNode cur; |
162 |
|
visit.push_back(src); |
163 |
|
do |
164 |
|
{ |
165 |
|
cur = visit.back(); |
166 |
|
it = visited.find(cur); |
167 |
|
if (it == visited.end()) |
168 |
|
{ |
169 |
|
// if it is a non-list variable, do the replacement |
170 |
|
itv = std::find(vars.begin(), vars.end(), cur); |
171 |
|
if (itv != vars.end()) |
172 |
|
{ |
173 |
|
size_t d = std::distance(vars.begin(), itv); |
174 |
|
if (!isListVar(vars[d])) |
175 |
|
{ |
176 |
|
visited[cur] = subs[d]; |
177 |
|
continue; |
178 |
|
} |
179 |
|
} |
180 |
|
visited[cur] = Node::null(); |
181 |
|
visit.insert(visit.end(), cur.begin(), cur.end()); |
182 |
|
continue; |
183 |
|
} |
184 |
|
visit.pop_back(); |
185 |
|
if (it->second.isNull()) |
186 |
|
{ |
187 |
|
Node ret = cur; |
188 |
|
bool childChanged = false; |
189 |
|
std::vector<Node> children; |
190 |
|
for (const Node& cn : cur) |
191 |
|
{ |
192 |
|
// if it is a list variable, insert the corresponding list as children; |
193 |
|
itv = std::find(vars.begin(), vars.end(), cn); |
194 |
|
if (itv != vars.end()) |
195 |
|
{ |
196 |
|
childChanged = true; |
197 |
|
size_t d = std::distance(vars.begin(), itv); |
198 |
|
Assert(d < subs.size()); |
199 |
|
Node sd = subs[d]; |
200 |
|
if (isListVar(vars[d])) |
201 |
|
{ |
202 |
|
Assert(sd.getKind() == SEXPR); |
203 |
|
// add its children |
204 |
|
children.insert(children.end(), sd.begin(), sd.end()); |
205 |
|
} |
206 |
|
else |
207 |
|
{ |
208 |
|
children.push_back(sd); |
209 |
|
} |
210 |
|
continue; |
211 |
|
} |
212 |
|
it = visited.find(cn); |
213 |
|
Assert(it != visited.end()); |
214 |
|
Assert(!it->second.isNull()); |
215 |
|
childChanged = childChanged || cn != it->second; |
216 |
|
children.push_back(it->second); |
217 |
|
} |
218 |
|
if (childChanged) |
219 |
|
{ |
220 |
|
if (children.size() != cur.getNumChildren()) |
221 |
|
{ |
222 |
|
// n-ary operators cannot be parameterized |
223 |
|
Assert(cur.getMetaKind() != metakind::PARAMETERIZED); |
224 |
|
ret = children.empty() |
225 |
|
? getNullTerminator(cur.getKind(), cur.getType()) |
226 |
|
: (children.size() == 1 |
227 |
|
? children[0] |
228 |
|
: nm->mkNode(cur.getKind(), children)); |
229 |
|
} |
230 |
|
else |
231 |
|
{ |
232 |
|
if (cur.getMetaKind() == metakind::PARAMETERIZED) |
233 |
|
{ |
234 |
|
children.insert(children.begin(), cur.getOperator()); |
235 |
|
} |
236 |
|
ret = nm->mkNode(cur.getKind(), children); |
237 |
|
} |
238 |
|
} |
239 |
|
visited[cur] = ret; |
240 |
|
} |
241 |
|
|
242 |
|
} while (!visit.empty()); |
243 |
|
Assert(visited.find(src) != visited.end()); |
244 |
|
Assert(!visited.find(src)->second.isNull()); |
245 |
|
return visited[src]; |
246 |
|
} |
247 |
|
|
248 |
|
} // namespace expr |
249 |
29340 |
} // namespace cvc5 |