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
|
//===-- Arena.cpp ---------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "clang/Analysis/FlowSensitive/Arena.h"
#include "clang/Analysis/FlowSensitive/Formula.h"
#include "clang/Analysis/FlowSensitive/Value.h"
#include "llvm/Support/Error.h"
#include <string>
namespace clang::dataflow {
static std::pair<const Formula *, const Formula *>
canonicalFormulaPair(const Formula &LHS, const Formula &RHS) {
auto Res = std::make_pair(&LHS, &RHS);
if (&RHS < &LHS) // FIXME: use a deterministic order instead
std::swap(Res.first, Res.second);
return Res;
}
template <class Key, class ComputeFunc>
static const Formula &cached(llvm::DenseMap<Key, const Formula *> &Cache, Key K,
ComputeFunc &&Compute) {
auto [It, Inserted] = Cache.try_emplace(std::forward<Key>(K));
if (Inserted)
It->second = Compute();
return *It->second;
}
const Formula &Arena::makeAtomRef(Atom A) {
return cached(AtomRefs, A, [&] {
return &Formula::create(Alloc, Formula::AtomRef, {},
static_cast<unsigned>(A));
});
}
const Formula &Arena::makeAnd(const Formula &LHS, const Formula &RHS) {
return cached(Ands, canonicalFormulaPair(LHS, RHS), [&] {
if (&LHS == &RHS)
return &LHS;
if (LHS.kind() == Formula::Literal)
return LHS.literal() ? &RHS : &LHS;
if (RHS.kind() == Formula::Literal)
return RHS.literal() ? &LHS : &RHS;
return &Formula::create(Alloc, Formula::And, {&LHS, &RHS});
});
}
const Formula &Arena::makeOr(const Formula &LHS, const Formula &RHS) {
return cached(Ors, canonicalFormulaPair(LHS, RHS), [&] {
if (&LHS == &RHS)
return &LHS;
if (LHS.kind() == Formula::Literal)
return LHS.literal() ? &LHS : &RHS;
if (RHS.kind() == Formula::Literal)
return RHS.literal() ? &RHS : &LHS;
return &Formula::create(Alloc, Formula::Or, {&LHS, &RHS});
});
}
const Formula &Arena::makeNot(const Formula &Val) {
return cached(Nots, &Val, [&] {
if (Val.kind() == Formula::Not)
return Val.operands()[0];
if (Val.kind() == Formula::Literal)
return &makeLiteral(!Val.literal());
return &Formula::create(Alloc, Formula::Not, {&Val});
});
}
const Formula &Arena::makeImplies(const Formula &LHS, const Formula &RHS) {
return cached(Implies, std::make_pair(&LHS, &RHS), [&] {
if (&LHS == &RHS)
return &makeLiteral(true);
if (LHS.kind() == Formula::Literal)
return LHS.literal() ? &RHS : &makeLiteral(true);
if (RHS.kind() == Formula::Literal)
return RHS.literal() ? &RHS : &makeNot(LHS);
return &Formula::create(Alloc, Formula::Implies, {&LHS, &RHS});
});
}
const Formula &Arena::makeEquals(const Formula &LHS, const Formula &RHS) {
return cached(Equals, canonicalFormulaPair(LHS, RHS), [&] {
if (&LHS == &RHS)
return &makeLiteral(true);
if (LHS.kind() == Formula::Literal)
return LHS.literal() ? &RHS : &makeNot(RHS);
if (RHS.kind() == Formula::Literal)
return RHS.literal() ? &LHS : &makeNot(LHS);
return &Formula::create(Alloc, Formula::Equal, {&LHS, &RHS});
});
}
IntegerValue &Arena::makeIntLiteral(llvm::APInt Value) {
auto [It, Inserted] = IntegerLiterals.try_emplace(Value, nullptr);
if (Inserted)
It->second = &create<IntegerValue>();
return *It->second;
}
BoolValue &Arena::makeBoolValue(const Formula &F) {
auto [It, Inserted] = FormulaValues.try_emplace(&F);
if (Inserted)
It->second = (F.kind() == Formula::AtomRef)
? (BoolValue *)&create<AtomicBoolValue>(F)
: &create<FormulaBoolValue>(F);
return *It->second;
}
namespace {
const Formula *parse(Arena &A, llvm::StringRef &In) {
auto EatSpaces = [&] { In = In.ltrim(' '); };
EatSpaces();
if (In.consume_front("!")) {
if (auto *Arg = parse(A, In))
return &A.makeNot(*Arg);
return nullptr;
}
if (In.consume_front("(")) {
auto *Arg1 = parse(A, In);
if (!Arg1)
return nullptr;
EatSpaces();
decltype(&Arena::makeOr) Op;
if (In.consume_front("|"))
Op = &Arena::makeOr;
else if (In.consume_front("&"))
Op = &Arena::makeAnd;
else if (In.consume_front("=>"))
Op = &Arena::makeImplies;
else if (In.consume_front("="))
Op = &Arena::makeEquals;
else
return nullptr;
auto *Arg2 = parse(A, In);
if (!Arg2)
return nullptr;
EatSpaces();
if (!In.consume_front(")"))
return nullptr;
return &(A.*Op)(*Arg1, *Arg2);
}
// For now, only support unnamed variables V0, V1 etc.
// FIXME: parse e.g. "X" by allocating an atom and storing a name somewhere.
if (In.consume_front("V")) {
std::underlying_type_t<Atom> At;
if (In.consumeInteger(10, At))
return nullptr;
return &A.makeAtomRef(static_cast<Atom>(At));
}
if (In.consume_front("true"))
return &A.makeLiteral(true);
if (In.consume_front("false"))
return &A.makeLiteral(false);
return nullptr;
}
class FormulaParseError : public llvm::ErrorInfo<FormulaParseError> {
std::string Formula;
unsigned Offset;
public:
static char ID;
FormulaParseError(llvm::StringRef Formula, unsigned Offset)
: Formula(Formula), Offset(Offset) {}
void log(raw_ostream &OS) const override {
OS << "bad formula at offset " << Offset << "\n";
OS << Formula << "\n";
OS.indent(Offset) << "^";
}
std::error_code convertToErrorCode() const override {
return std::make_error_code(std::errc::invalid_argument);
}
};
char FormulaParseError::ID = 0;
} // namespace
llvm::Expected<const Formula &> Arena::parseFormula(llvm::StringRef In) {
llvm::StringRef Rest = In;
auto *Result = parse(*this, Rest);
if (!Result) // parse() hit something unparseable
return llvm::make_error<FormulaParseError>(In, In.size() - Rest.size());
Rest = Rest.ltrim();
if (!Rest.empty()) // parse didn't consume all the input
return llvm::make_error<FormulaParseError>(In, In.size() - Rest.size());
return *Result;
}
} // namespace clang::dataflow
|
