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
|
//===-- MergeHandler.cpp --------------------------------------------------===//
//
// The KLEE Symbolic Virtual Machine
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "MergeHandler.h"
#include "CoreStats.h"
#include "ExecutionState.h"
#include "Executor.h"
#include "Searcher.h"
namespace klee {
/*** Test generation options ***/
llvm::cl::OptionCategory MergeCat("Path merging options",
"These options control path merging.");
llvm::cl::opt<bool> UseMerge(
"use-merge", llvm::cl::init(false),
llvm::cl::desc("Enable support for path merging via klee_open_merge and "
"klee_close_merge (default=false)"),
llvm::cl::cat(klee::MergeCat));
llvm::cl::opt<bool> DebugLogMerge(
"debug-log-merge", llvm::cl::init(false),
llvm::cl::desc("Debug information for path merging (default=false)"),
llvm::cl::cat(klee::MergeCat));
llvm::cl::opt<bool> UseIncompleteMerge(
"use-incomplete-merge", llvm::cl::init(false),
llvm::cl::desc("Heuristic-based path merging (default=false)"),
llvm::cl::cat(klee::MergeCat));
llvm::cl::opt<bool> DebugLogIncompleteMerge(
"debug-log-incomplete-merge", llvm::cl::init(false),
llvm::cl::desc("Debug information for incomplete path merging (default=false)"),
llvm::cl::cat(klee::MergeCat));
double MergeHandler::getMean() {
if (closedStateCount == 0)
return 0;
return closedMean;
}
unsigned MergeHandler::getInstructionDistance(ExecutionState *es){
return es->steppedInstructions - openInstruction;
}
ExecutionState *MergeHandler::getPrioritizeState(){
for (ExecutionState *cur_state : openStates) {
bool stateIsClosed =
(executor->mergingSearcher->inCloseMerge.find(cur_state) !=
executor->mergingSearcher->inCloseMerge.end());
if (!stateIsClosed && (getInstructionDistance(cur_state) < 2 * getMean())) {
return cur_state;
}
}
return 0;
}
void MergeHandler::addOpenState(ExecutionState *es){
openStates.push_back(es);
}
void MergeHandler::removeOpenState(ExecutionState *es){
auto it = std::find(openStates.begin(), openStates.end(), es);
assert(it != openStates.end());
std::swap(*it, openStates.back());
openStates.pop_back();
}
void MergeHandler::addClosedState(ExecutionState *es,
llvm::Instruction *mp) {
// Update stats
++closedStateCount;
// Incremental update of mean (travelling mean)
// https://math.stackexchange.com/a/1836447
closedMean += (static_cast<double>(getInstructionDistance(es)) - closedMean) /
closedStateCount;
// Remove from openStates
removeOpenState(es);
auto closePoint = reachedCloseMerge.find(mp);
// If no other state has yet encountered this klee_close_merge instruction,
// add a new element to the map
if (closePoint == reachedCloseMerge.end()) {
reachedCloseMerge[mp].push_back(es);
executor->mergingSearcher->pauseState(*es);
} else {
// Otherwise try to merge with any state in the map element for this
// instruction
auto &cpv = closePoint->second;
bool mergedSuccessful = false;
for (auto& mState: cpv) {
if (mState->merge(*es)) {
executor->terminateStateEarlyAlgorithm(*es, "merged state.", StateTerminationType::Merge);
executor->mergingSearcher->inCloseMerge.erase(es);
mergedSuccessful = true;
break;
}
}
if (!mergedSuccessful) {
cpv.push_back(es);
executor->mergingSearcher->pauseState(*es);
}
}
}
void MergeHandler::releaseStates() {
for (auto& curMergeGroup: reachedCloseMerge) {
for (auto curState: curMergeGroup.second) {
executor->mergingSearcher->continueState(*curState);
executor->mergingSearcher->inCloseMerge.erase(curState);
}
}
reachedCloseMerge.clear();
}
bool MergeHandler::hasMergedStates() {
return (!reachedCloseMerge.empty());
}
MergeHandler::MergeHandler(Executor *_executor, ExecutionState *es)
: executor(_executor), openInstruction(es->steppedInstructions),
closedMean(0), closedStateCount(0) {
executor->mergingSearcher->mergeGroups.push_back(this);
addOpenState(es);
}
MergeHandler::~MergeHandler() {
auto it = std::find(executor->mergingSearcher->mergeGroups.begin(),
executor->mergingSearcher->mergeGroups.end(), this);
assert(it != executor->mergingSearcher->mergeGroups.end() &&
"All MergeHandlers should be registered in mergeGroups");
std::swap(*it, executor->mergingSearcher->mergeGroups.back());
executor->mergingSearcher->mergeGroups.pop_back();
releaseStates();
}
}
|
