1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
/********************* */
/*! \file node.cpp
** \verbatim
** Top contributors (to current version):
** Morgan Deters, Andrew Reynolds, Tim King
** This file is part of the CVC4 project.
** Copyright (c) 2009-2018 by the authors listed in the file AUTHORS
** in the top-level source directory) and their institutional affiliations.
** All rights reserved. See the file COPYING in the top-level source
** directory for licensing information.\endverbatim
**
** \brief Reference-counted encapsulation of a pointer to node information.
**
** Reference-counted encapsulation of a pointer to node information.
**/
#include "expr/node.h"
#include <iostream>
#include <cstring>
#include "base/exception.h"
#include "base/output.h"
#include "expr/attribute.h"
using namespace std;
namespace CVC4 {
TypeCheckingExceptionPrivate::TypeCheckingExceptionPrivate(TNode node,
std::string message)
: Exception(message), d_node(new Node(node))
{
#ifdef CVC4_DEBUG
std::stringstream ss;
LastExceptionBuffer* current = LastExceptionBuffer::getCurrent();
if(current != NULL){
// Since this node is malformed, we cannot use toString().
// Instead, we print the kind and the children.
ss << "node kind: " << node.getKind() << ". children: ";
int i = 0;
for (const TNode& child : node)
{
ss << "child[" << i << "]: " << child << ". ";
i++;
}
string ssstring = ss.str();
current->setContents(ssstring.c_str());
}
#endif /* CVC4_DEBUG */
}
TypeCheckingExceptionPrivate::~TypeCheckingExceptionPrivate() { delete d_node; }
void TypeCheckingExceptionPrivate::toStream(std::ostream& os) const
{
os << "Error during type checking: " << d_msg << std::endl << *d_node << endl << "The ill-typed expression: " << *d_node;
}
NodeTemplate<true> TypeCheckingExceptionPrivate::getNode() const
{
return *d_node;
}
UnknownTypeException::UnknownTypeException(TNode n)
: TypeCheckingExceptionPrivate(
n,
"this expression contains an element of unknown type (such as an "
"abstract value);"
" its type cannot be computed until it is substituted away")
{
}
/** Is this node constant? (and has that been computed yet?) */
struct IsConstTag { };
struct IsConstComputedTag { };
struct HasBoundVarTag { };
struct HasBoundVarComputedTag { };
typedef expr::Attribute<IsConstTag, bool> IsConstAttr;
typedef expr::Attribute<IsConstComputedTag, bool> IsConstComputedAttr;
/** Attribute true for expressions with bound variables in them */
typedef expr::Attribute<HasBoundVarTag, bool> HasBoundVarAttr;
typedef expr::Attribute<HasBoundVarComputedTag, bool> HasBoundVarComputedAttr;
template <bool ref_count>
bool NodeTemplate<ref_count>::isConst() const {
assertTNodeNotExpired();
Debug("isConst") << "Node::isConst() for: " << *this << std::endl;
if(isNull()) {
return false;
}
switch(getMetaKind()) {
case kind::metakind::CONSTANT:
Debug("isConst") << "Node::isConst() returning true, it's a CONSTANT" << std::endl;
return true;
case kind::metakind::VARIABLE:
Debug("isConst") << "Node::isConst() returning false, it's a VARIABLE" << std::endl;
return false;
default:
if(expr::TypeChecker::neverIsConst(NodeManager::currentNM(), *this)){
Debug("isConst") << "Node::isConst() returning false, the kind is never const" << std::endl;
return false;
}
if(getAttribute(IsConstComputedAttr())) {
bool bval = getAttribute(IsConstAttr());
Debug("isConst") << "Node::isConst() returning cached value " << (bval ? "true" : "false") << " for: " << *this << std::endl;
return bval;
} else {
bool bval = expr::TypeChecker::computeIsConst(NodeManager::currentNM(), *this);
Debug("isConst") << "Node::isConst() computed value " << (bval ? "true" : "false") << " for: " << *this << std::endl;
const_cast< NodeTemplate<ref_count>* >(this)->setAttribute(IsConstAttr(), bval);
const_cast< NodeTemplate<ref_count>* >(this)->setAttribute(IsConstComputedAttr(), true);
return bval;
}
}
}
template <bool ref_count>
bool NodeTemplate<ref_count>::hasBoundVar() {
assertTNodeNotExpired();
if(! getAttribute(HasBoundVarComputedAttr())) {
bool hasBv = false;
if(getKind() == kind::BOUND_VARIABLE) {
hasBv = true;
} else {
for(iterator i = begin(); i != end() && !hasBv; ++i) {
hasBv = (*i).hasBoundVar();
}
}
if (!hasBv && hasOperator()) {
hasBv = getOperator().hasBoundVar();
}
setAttribute(HasBoundVarAttr(), hasBv);
setAttribute(HasBoundVarComputedAttr(), true);
Debug("bva") << *this << " has bva : " << getAttribute(HasBoundVarAttr()) << std::endl;
return hasBv;
}
return getAttribute(HasBoundVarAttr());
}
template <bool ref_count>
bool NodeTemplate<ref_count>::hasFreeVar()
{
assertTNodeNotExpired();
std::unordered_set<TNode, TNodeHashFunction> bound_var;
std::unordered_map<TNode, bool, TNodeHashFunction> visited;
std::vector<TNode> visit;
TNode cur;
visit.push_back(*this);
do
{
cur = visit.back();
visit.pop_back();
// can skip if it doesn't have a bound variable
if (!cur.hasBoundVar())
{
continue;
}
Kind k = cur.getKind();
bool isQuant = k == kind::FORALL || k == kind::EXISTS || k == kind::LAMBDA
|| k == kind::CHOICE;
std::unordered_map<TNode, bool, TNodeHashFunction>::iterator itv =
visited.find(cur);
if (itv == visited.end())
{
if (k == kind::BOUND_VARIABLE)
{
if (bound_var.find(cur) == bound_var.end())
{
return true;
}
}
else if (isQuant)
{
for (const TNode& cn : cur[0])
{
// should not shadow
Assert(bound_var.find(cn) == bound_var.end());
bound_var.insert(cn);
}
visit.push_back(cur);
}
// must visit quantifiers again to clean up below
visited[cur] = !isQuant;
if (cur.hasOperator())
{
visit.push_back(cur.getOperator());
}
for (const TNode& cn : cur)
{
visit.push_back(cn);
}
}
else if (!itv->second)
{
Assert(isQuant);
for (const TNode& cn : cur[0])
{
bound_var.erase(cn);
}
visited[cur] = true;
}
} while (!visit.empty());
return false;
}
template bool NodeTemplate<true>::isConst() const;
template bool NodeTemplate<false>::isConst() const;
template bool NodeTemplate<true>::hasBoundVar();
template bool NodeTemplate<false>::hasBoundVar();
template bool NodeTemplate<true>::hasFreeVar();
template bool NodeTemplate<false>::hasFreeVar();
}/* CVC4 namespace */
|
