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
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
|
//===-- ExprPPrinter.cpp - ----------------------------------------------===//
//
// The KLEE Symbolic Virtual Machine
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "klee/Expr/ExprPPrinter.h"
#include "klee/Expr/Constraints.h"
#include "klee/OptionCategories.h"
#include "klee/Support/PrintContext.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/raw_ostream.h"
#include <map>
#include <vector>
using namespace klee;
namespace {
llvm::cl::opt<bool> PCWidthAsArg(
"pc-width-as-arg", llvm::cl::init(true),
llvm::cl::desc(
"Print the width as a separate argument, as opposed to a prefix "
"to the operation (default=true)"),
llvm::cl::cat(klee::ExprCat));
llvm::cl::opt<bool>
PCAllWidths("pc-all-widths", llvm::cl::init(false),
llvm::cl::desc("Print the width of all operations, including "
"booleans (default=false)"),
llvm::cl::cat(klee::ExprCat));
llvm::cl::opt<bool>
PCPrefixWidth("pc-prefix-width", llvm::cl::init(true),
llvm::cl::desc("Print width with 'w' prefix (default=true)"),
llvm::cl::cat(klee::ExprCat));
llvm::cl::opt<bool>
PCMultibyteReads("pc-multibyte-reads", llvm::cl::init(true),
llvm::cl::desc("Print ReadLSB and ReadMSB expressions "
"when possible (default=true)"),
llvm::cl::cat(klee::ExprCat));
llvm::cl::opt<bool> PCAllConstWidths(
"pc-all-const-widths", llvm::cl::init(false),
llvm::cl::desc(
"Always print the width of constant expressions (default=false)"),
llvm::cl::cat(klee::ExprCat));
} // namespace
class PPrinter : public ExprPPrinter {
public:
std::set<const Array*> usedArrays;
private:
std::map<ref<Expr>, unsigned> bindings;
std::map<const UpdateNode*, unsigned> updateBindings;
std::set< ref<Expr> > couldPrint, shouldPrint;
std::set<const UpdateNode*> couldPrintUpdates, shouldPrintUpdates;
llvm::raw_ostream &os;
unsigned counter;
unsigned updateCounter;
bool hasScan;
bool forceNoLineBreaks;
std::string newline;
/// shouldPrintWidth - Predicate for whether this expression should
/// be printed with its width.
bool shouldPrintWidth(ref<Expr> e) {
if (PCAllWidths)
return true;
return e->getWidth() != Expr::Bool;
}
bool isVerySimple(const ref<Expr> &e) {
return isa<ConstantExpr>(e) || bindings.find(e)!=bindings.end();
}
bool isVerySimpleUpdate(const UpdateNode *un) {
return !un || updateBindings.find(un)!=updateBindings.end();
}
// document me!
bool isSimple(const ref<Expr> &e) {
if (isVerySimple(e)) {
return true;
} else if (const ReadExpr *re = dyn_cast<ReadExpr>(e)) {
return isVerySimple(re->index) &&
isVerySimpleUpdate(re->updates.head.get());
} else {
Expr *ep = e.get();
for (unsigned i=0; i<ep->getNumKids(); i++)
if (!isVerySimple(ep->getKid(i)))
return false;
return true;
}
}
bool hasSimpleKids(const Expr *ep) {
for (unsigned i=0; i<ep->getNumKids(); i++)
if (!isSimple(ep->getKid(i)))
return false;
return true;
}
void scanUpdate(const UpdateNode *un) {
// FIXME: This needs to be non-recursive.
if (un) {
if (couldPrintUpdates.insert(un).second) {
scanUpdate(un->next.get());
scan1(un->index);
scan1(un->value);
} else {
shouldPrintUpdates.insert(un);
}
}
}
void scan1(const ref<Expr> &e) {
if (!isa<ConstantExpr>(e)) {
if (couldPrint.insert(e).second) {
Expr *ep = e.get();
for (unsigned i=0; i<ep->getNumKids(); i++)
scan1(ep->getKid(i));
if (const ReadExpr *re = dyn_cast<ReadExpr>(e)) {
usedArrays.insert(re->updates.root);
scanUpdate(re->updates.head.get());
}
} else {
shouldPrint.insert(e);
}
}
}
void printUpdateList(const UpdateList &updates, PrintContext &PC) {
auto head = updates.head;
// Special case empty list.
if (head.isNull()) {
// FIXME: We need to do something (assert, mangle, etc.) so that printing
// distinct arrays with the same name doesn't fail.
PC << updates.root->name;
return;
}
// FIXME: Explain this breaking policy.
bool openedList = false, nextShouldBreak = false;
unsigned outerIndent = PC.pos;
unsigned middleIndent = 0;
for (auto un = head; !un.isNull(); un = un->next) {
// We are done if we hit the cache.
std::map<const UpdateNode *, unsigned>::iterator it =
updateBindings.find(un.get());
if (it!=updateBindings.end()) {
if (openedList)
PC << "] @ ";
PC << "U" << it->second;
return;
} else if (!hasScan || shouldPrintUpdates.count(un.get())) {
if (openedList)
PC << "] @";
if (un != head)
PC.breakLine(outerIndent);
PC << "U" << updateCounter << ":";
updateBindings.insert(std::make_pair(un.get(), updateCounter++));
openedList = nextShouldBreak = false;
}
if (!openedList) {
openedList = 1;
PC << '[';
middleIndent = PC.pos;
} else {
PC << ',';
printSeparator(PC, !nextShouldBreak, middleIndent);
}
//PC << "(=";
//unsigned innerIndent = PC.pos;
print(un->index, PC);
//printSeparator(PC, isSimple(un->index), innerIndent);
PC << "=";
print(un->value, PC);
//PC << ')';
nextShouldBreak = !(isa<ConstantExpr>(un->index) &&
isa<ConstantExpr>(un->value));
}
if (openedList)
PC << ']';
PC << " @ " << updates.root->name;
}
void printWidth(PrintContext &PC, ref<Expr> e) {
if (!shouldPrintWidth(e))
return;
if (PCWidthAsArg) {
PC << ' ';
if (PCPrefixWidth)
PC << 'w';
}
PC << e->getWidth();
}
bool isReadExprAtOffset(ref<Expr> e, const ReadExpr *base, ref<Expr> offset) {
const ReadExpr *re = dyn_cast<ReadExpr>(e.get());
// right now, all Reads are byte reads but some
// transformations might change this
if (!re || (re->getWidth() != Expr::Int8))
return false;
// Check if the index follows the stride.
// FIXME: How aggressive should this be simplified. The
// canonicalizing builder is probably the right choice, but this
// is yet another area where we would really prefer it to be
// global or else use static methods.
return SubExpr::create(re->index, base->index) == offset;
}
/// hasOrderedReads: \arg e must be a ConcatExpr, \arg stride must
/// be 1 or -1.
///
/// If all children of this Concat are reads or concats of reads
/// with consecutive offsets according to the given \arg stride, it
/// returns the base ReadExpr according to \arg stride: first Read
/// for 1 (MSB), last Read for -1 (LSB). Otherwise, it returns
/// null.
const ReadExpr* hasOrderedReads(ref<Expr> e, int stride) {
assert(e->getKind() == Expr::Concat);
assert(stride == 1 || stride == -1);
const ReadExpr *base = dyn_cast<ReadExpr>(e->getKid(0));
// right now, all Reads are byte reads but some
// transformations might change this
if (!base || base->getWidth() != Expr::Int8)
return NULL;
// Get stride expr in proper index width.
Expr::Width idxWidth = base->index->getWidth();
ref<Expr> strideExpr = ConstantExpr::alloc(stride, idxWidth);
ref<Expr> offset = ConstantExpr::create(0, idxWidth);
e = e->getKid(1);
// concat chains are unbalanced to the right
while (e->getKind() == Expr::Concat) {
offset = AddExpr::create(offset, strideExpr);
if (!isReadExprAtOffset(e->getKid(0), base, offset))
return NULL;
e = e->getKid(1);
}
offset = AddExpr::create(offset, strideExpr);
if (!isReadExprAtOffset(e, base, offset))
return NULL;
if (stride == -1)
return cast<ReadExpr>(e.get());
else return base;
}
#if 0
/// hasAllByteReads - True iff all children are byte level reads or
/// concats of byte level reads.
bool hasAllByteReads(const Expr *ep) {
switch (ep->kind) {
Expr::Read: {
// right now, all Reads are byte reads but some
// transformations might change this
return ep->getWidth() == Expr::Int8;
}
Expr::Concat: {
for (unsigned i=0; i<ep->getNumKids(); ++i) {
if (!hashAllByteReads(ep->getKid(i)))
return false;
}
}
default: return false;
}
}
#endif
void printRead(const ReadExpr *re, PrintContext &PC, unsigned indent) {
print(re->index, PC);
printSeparator(PC, isVerySimple(re->index), indent);
printUpdateList(re->updates, PC);
}
void printExtract(const ExtractExpr *ee, PrintContext &PC, unsigned indent) {
PC << ee->offset << ' ';
print(ee->expr, PC);
}
void printExpr(const Expr *ep, PrintContext &PC, unsigned indent, bool printConstWidth=false) {
bool simple = hasSimpleKids(ep);
print(ep->getKid(0), PC);
for (unsigned i=1; i<ep->getNumKids(); i++) {
printSeparator(PC, simple, indent);
print(ep->getKid(i), PC, printConstWidth);
}
}
public:
PPrinter(llvm::raw_ostream &_os) : os(_os), newline("\n") {
reset();
}
void setNewline(const std::string &_newline) {
newline = _newline;
}
void setForceNoLineBreaks(bool _forceNoLineBreaks) {
forceNoLineBreaks = _forceNoLineBreaks;
}
void reset() {
counter = 0;
updateCounter = 0;
hasScan = false;
forceNoLineBreaks = false;
bindings.clear();
updateBindings.clear();
couldPrint.clear();
shouldPrint.clear();
couldPrintUpdates.clear();
shouldPrintUpdates.clear();
}
void scan(const ref<Expr> &e) {
hasScan = true;
scan1(e);
}
void print(const ref<Expr> &e, unsigned level=0) {
PrintContext PC(os);
PC.pos = level;
print(e, PC);
}
void printConst(const ref<ConstantExpr> &e, PrintContext &PC,
bool printWidth) {
if (e->getWidth() == Expr::Bool)
PC << (e->isTrue() ? "true" : "false");
else {
if (PCAllConstWidths)
printWidth = true;
if (printWidth)
PC << "(w" << e->getWidth() << " ";
if (e->getWidth() <= 64) {
PC << e->getZExtValue();
} else {
std::string S;
e->toString(S);
PC << S;
}
if (printWidth)
PC << ")";
}
}
void print(const ref<Expr> &e, PrintContext &PC, bool printConstWidth=false) {
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(e))
printConst(CE, PC, printConstWidth);
else {
std::map<ref<Expr>, unsigned>::iterator it = bindings.find(e);
if (it!=bindings.end()) {
PC << 'N' << it->second;
} else {
if (!hasScan || shouldPrint.count(e)) {
PC << 'N' << counter << ':';
bindings.insert(std::make_pair(e, counter++));
}
// Detect multibyte reads.
// FIXME: Hrm. One problem with doing this is that we are
// masking the sharing of the indices which aren't
// visible. Need to think if this matters... probably not
// because if they are offset reads then its either constant,
// or they are (base + offset) and base will get printed with
// a declaration.
if (PCMultibyteReads && e->getKind() == Expr::Concat) {
const ReadExpr *base = hasOrderedReads(e, -1);
const bool isLSB = (base != nullptr);
if (!isLSB)
base = hasOrderedReads(e, 1);
if (base) {
PC << "(Read" << (isLSB ? "LSB" : "MSB");
printWidth(PC, e);
PC << ' ';
printRead(base, PC, PC.pos);
PC << ')';
return;
}
}
PC << '(' << e->getKind();
printWidth(PC, e);
PC << ' ';
// Indent at first argument and dispatch to appropriate print
// routine for exprs which require special handling.
unsigned indent = PC.pos;
if (const ReadExpr *re = dyn_cast<ReadExpr>(e)) {
printRead(re, PC, indent);
} else if (const ExtractExpr *ee = dyn_cast<ExtractExpr>(e)) {
printExtract(ee, PC, indent);
} else if (e->getKind() == Expr::Concat || e->getKind() == Expr::SExt)
printExpr(e.get(), PC, indent, true);
else
printExpr(e.get(), PC, indent);
PC << ")";
}
}
}
/* Public utility functions */
void printSeparator(PrintContext &PC, bool simple, unsigned indent) {
if (simple || forceNoLineBreaks) {
PC << ' ';
} else {
PC.breakLine(indent);
}
}
};
ExprPPrinter *klee::ExprPPrinter::create(llvm::raw_ostream &os) {
return new PPrinter(os);
}
void ExprPPrinter::printOne(llvm::raw_ostream &os,
const char *message,
const ref<Expr> &e) {
PPrinter p(os);
p.scan(e);
// FIXME: Need to figure out what to do here. Probably print as a
// "forward declaration" with whatever syntax we pick for that.
PrintContext PC(os);
PC << message << ": ";
p.print(e, PC);
PC.breakLine();
}
void ExprPPrinter::printSingleExpr(llvm::raw_ostream &os, const ref<Expr> &e) {
PPrinter p(os);
p.scan(e);
// FIXME: Need to figure out what to do here. Probably print as a
// "forward declaration" with whatever syntax we pick for that.
PrintContext PC(os);
p.print(e, PC);
}
void ExprPPrinter::printConstraints(llvm::raw_ostream &os,
const ConstraintManager &constraints) {
printQuery(os, constraints, ConstantExpr::alloc(false, Expr::Bool));
}
namespace {
struct ArrayPtrsByName {
bool operator()(const Array *a1, const Array *a2) const {
return a1->name < a2->name;
}
};
}
void ExprPPrinter::printQuery(llvm::raw_ostream &os,
const ConstraintManager &constraints,
const ref<Expr> &q,
const ref<Expr> *evalExprsBegin,
const ref<Expr> *evalExprsEnd,
const Array * const *evalArraysBegin,
const Array * const *evalArraysEnd,
bool printArrayDecls) {
PPrinter p(os);
for (ConstraintManager::const_iterator it = constraints.begin(),
ie = constraints.end(); it != ie; ++it)
p.scan(*it);
p.scan(q);
for (const ref<Expr> *it = evalExprsBegin; it != evalExprsEnd; ++it)
p.scan(*it);
PrintContext PC(os);
// Print array declarations.
if (printArrayDecls) {
for (const Array * const* it = evalArraysBegin; it != evalArraysEnd; ++it)
p.usedArrays.insert(*it);
std::vector<const Array *> sortedArray(p.usedArrays.begin(),
p.usedArrays.end());
std::sort(sortedArray.begin(), sortedArray.end(), ArrayPtrsByName());
for (std::vector<const Array *>::iterator it = sortedArray.begin(),
ie = sortedArray.end();
it != ie; ++it) {
const Array *A = *it;
PC << "array " << A->name << "[" << A->size << "]"
<< " : w" << A->domain << " -> w" << A->range << " = ";
if (A->isSymbolicArray()) {
PC << "symbolic";
} else {
PC << "[";
for (unsigned i = 0, e = A->size; i != e; ++i) {
if (i)
PC << " ";
PC << A->constantValues[i];
}
PC << "]";
}
PC.breakLine();
}
}
PC << "(query [";
// Ident at constraint list;
unsigned indent = PC.pos;
for (ConstraintManager::const_iterator it = constraints.begin(),
ie = constraints.end(); it != ie;) {
p.print(*it, PC);
++it;
if (it != ie)
PC.breakLine(indent);
}
PC << ']';
p.printSeparator(PC, constraints.empty(), indent-1);
p.print(q, PC);
// Print expressions to obtain values for, if any.
if (evalExprsBegin != evalExprsEnd) {
p.printSeparator(PC, q->isFalse(), indent-1);
PC << '[';
for (const ref<Expr> *it = evalExprsBegin; it != evalExprsEnd; ++it) {
p.print(*it, PC, /*printConstWidth*/true);
if (it + 1 != evalExprsEnd)
PC.breakLine(indent);
}
PC << ']';
}
// Print arrays to obtain values for, if any.
if (evalArraysBegin != evalArraysEnd) {
if (evalExprsBegin == evalExprsEnd)
PC << " []";
PC.breakLine(indent - 1);
PC << '[';
for (const Array * const* it = evalArraysBegin; it != evalArraysEnd; ++it) {
PC << (*it)->name;
if (it + 1 != evalArraysEnd)
PC.breakLine(indent);
}
PC << ']';
}
PC << ')';
PC.breakLine();
}
|