1 //===- ThreadSafetyTIL.h ----------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines a simple Typed Intermediate Language, or TIL, that is used
10 // by the thread safety analysis (See ThreadSafety.cpp). The TIL is intended
11 // to be largely independent of clang, in the hope that the analysis can be
12 // reused for other non-C++ languages. All dependencies on clang/llvm should
13 // go in ThreadSafetyUtil.h.
14 //
15 // Thread safety analysis works by comparing mutex expressions, e.g.
16 //
17 // class A { Mutex mu; int dat GUARDED_BY(this->mu); }
18 // class B { A a; }
19 //
20 // void foo(B* b) {
21 // (*b).a.mu.lock(); // locks (*b).a.mu
22 // b->a.dat = 0; // substitute &b->a for 'this';
23 // // requires lock on (&b->a)->mu
24 // (b->a.mu).unlock(); // unlocks (b->a.mu)
25 // }
26 //
27 // As illustrated by the above example, clang Exprs are not well-suited to
28 // represent mutex expressions directly, since there is no easy way to compare
29 // Exprs for equivalence. The thread safety analysis thus lowers clang Exprs
30 // into a simple intermediate language (IL). The IL supports:
31 //
32 // (1) comparisons for semantic equality of expressions
33 // (2) SSA renaming of variables
34 // (3) wildcards and pattern matching over expressions
35 // (4) hash-based expression lookup
36 //
37 // The TIL is currently very experimental, is intended only for use within
38 // the thread safety analysis, and is subject to change without notice.
39 // After the API stabilizes and matures, it may be appropriate to make this
40 // more generally available to other analyses.
41 //
42 // UNDER CONSTRUCTION. USE AT YOUR OWN RISK.
43 //
44 //===----------------------------------------------------------------------===//
45
46 #ifndef LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYTIL_H
47 #define LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYTIL_H
48
49 #include "clang/AST/Decl.h"
50 #include "clang/Analysis/Analyses/ThreadSafetyUtil.h"
51 #include "clang/Basic/LLVM.h"
52 #include "llvm/ADT/ArrayRef.h"
53 #include "llvm/ADT/None.h"
54 #include "llvm/ADT/Optional.h"
55 #include "llvm/ADT/StringRef.h"
56 #include "llvm/Support/Casting.h"
57 #include "llvm/Support/raw_ostream.h"
58 #include <algorithm>
59 #include <cassert>
60 #include <cstddef>
61 #include <cstdint>
62 #include <iterator>
63 #include <string>
64 #include <utility>
65
66 namespace clang {
67
68 class CallExpr;
69 class Expr;
70 class Stmt;
71
72 namespace threadSafety {
73 namespace til {
74
75 class BasicBlock;
76
77 /// Enum for the different distinct classes of SExpr
78 enum TIL_Opcode {
79 #define TIL_OPCODE_DEF(X) COP_##X,
80 #include "ThreadSafetyOps.def"
81 #undef TIL_OPCODE_DEF
82 };
83
84 /// Opcode for unary arithmetic operations.
85 enum TIL_UnaryOpcode : unsigned char {
86 UOP_Minus, // -
87 UOP_BitNot, // ~
88 UOP_LogicNot // !
89 };
90
91 /// Opcode for binary arithmetic operations.
92 enum TIL_BinaryOpcode : unsigned char {
93 BOP_Add, // +
94 BOP_Sub, // -
95 BOP_Mul, // *
96 BOP_Div, // /
97 BOP_Rem, // %
98 BOP_Shl, // <<
99 BOP_Shr, // >>
100 BOP_BitAnd, // &
101 BOP_BitXor, // ^
102 BOP_BitOr, // |
103 BOP_Eq, // ==
104 BOP_Neq, // !=
105 BOP_Lt, // <
106 BOP_Leq, // <=
107 BOP_Cmp, // <=>
108 BOP_LogicAnd, // && (no short-circuit)
109 BOP_LogicOr // || (no short-circuit)
110 };
111
112 /// Opcode for cast operations.
113 enum TIL_CastOpcode : unsigned char {
114 CAST_none = 0,
115
116 // Extend precision of numeric type
117 CAST_extendNum,
118
119 // Truncate precision of numeric type
120 CAST_truncNum,
121
122 // Convert to floating point type
123 CAST_toFloat,
124
125 // Convert to integer type
126 CAST_toInt,
127
128 // Convert smart pointer to pointer (C++ only)
129 CAST_objToPtr
130 };
131
132 const TIL_Opcode COP_Min = COP_Future;
133 const TIL_Opcode COP_Max = COP_Branch;
134 const TIL_UnaryOpcode UOP_Min = UOP_Minus;
135 const TIL_UnaryOpcode UOP_Max = UOP_LogicNot;
136 const TIL_BinaryOpcode BOP_Min = BOP_Add;
137 const TIL_BinaryOpcode BOP_Max = BOP_LogicOr;
138 const TIL_CastOpcode CAST_Min = CAST_none;
139 const TIL_CastOpcode CAST_Max = CAST_toInt;
140
141 /// Return the name of a unary opcode.
142 StringRef getUnaryOpcodeString(TIL_UnaryOpcode Op);
143
144 /// Return the name of a binary opcode.
145 StringRef getBinaryOpcodeString(TIL_BinaryOpcode Op);
146
147 /// ValueTypes are data types that can actually be held in registers.
148 /// All variables and expressions must have a value type.
149 /// Pointer types are further subdivided into the various heap-allocated
150 /// types, such as functions, records, etc.
151 /// Structured types that are passed by value (e.g. complex numbers)
152 /// require special handling; they use BT_ValueRef, and size ST_0.
153 struct ValueType {
154 enum BaseType : unsigned char {
155 BT_Void = 0,
156 BT_Bool,
157 BT_Int,
158 BT_Float,
159 BT_String, // String literals
160 BT_Pointer,
161 BT_ValueRef
162 };
163
164 enum SizeType : unsigned char {
165 ST_0 = 0,
166 ST_1,
167 ST_8,
168 ST_16,
169 ST_32,
170 ST_64,
171 ST_128
172 };
173
ValueTypeValueType174 ValueType(BaseType B, SizeType Sz, bool S, unsigned char VS)
175 : Base(B), Size(Sz), Signed(S), VectSize(VS) {}
176
177 inline static SizeType getSizeType(unsigned nbytes);
178
179 template <class T>
180 inline static ValueType getValueType();
181
182 BaseType Base;
183 SizeType Size;
184 bool Signed;
185
186 // 0 for scalar, otherwise num elements in vector
187 unsigned char VectSize;
188 };
189
getSizeType(unsigned nbytes)190 inline ValueType::SizeType ValueType::getSizeType(unsigned nbytes) {
191 switch (nbytes) {
192 case 1: return ST_8;
193 case 2: return ST_16;
194 case 4: return ST_32;
195 case 8: return ST_64;
196 case 16: return ST_128;
197 default: return ST_0;
198 }
199 }
200
201 template<>
202 inline ValueType ValueType::getValueType<void>() {
203 return ValueType(BT_Void, ST_0, false, 0);
204 }
205
206 template<>
207 inline ValueType ValueType::getValueType<bool>() {
208 return ValueType(BT_Bool, ST_1, false, 0);
209 }
210
211 template<>
212 inline ValueType ValueType::getValueType<int8_t>() {
213 return ValueType(BT_Int, ST_8, true, 0);
214 }
215
216 template<>
217 inline ValueType ValueType::getValueType<uint8_t>() {
218 return ValueType(BT_Int, ST_8, false, 0);
219 }
220
221 template<>
222 inline ValueType ValueType::getValueType<int16_t>() {
223 return ValueType(BT_Int, ST_16, true, 0);
224 }
225
226 template<>
227 inline ValueType ValueType::getValueType<uint16_t>() {
228 return ValueType(BT_Int, ST_16, false, 0);
229 }
230
231 template<>
232 inline ValueType ValueType::getValueType<int32_t>() {
233 return ValueType(BT_Int, ST_32, true, 0);
234 }
235
236 template<>
237 inline ValueType ValueType::getValueType<uint32_t>() {
238 return ValueType(BT_Int, ST_32, false, 0);
239 }
240
241 template<>
242 inline ValueType ValueType::getValueType<int64_t>() {
243 return ValueType(BT_Int, ST_64, true, 0);
244 }
245
246 template<>
247 inline ValueType ValueType::getValueType<uint64_t>() {
248 return ValueType(BT_Int, ST_64, false, 0);
249 }
250
251 template<>
252 inline ValueType ValueType::getValueType<float>() {
253 return ValueType(BT_Float, ST_32, true, 0);
254 }
255
256 template<>
257 inline ValueType ValueType::getValueType<double>() {
258 return ValueType(BT_Float, ST_64, true, 0);
259 }
260
261 template<>
262 inline ValueType ValueType::getValueType<long double>() {
263 return ValueType(BT_Float, ST_128, true, 0);
264 }
265
266 template<>
267 inline ValueType ValueType::getValueType<StringRef>() {
268 return ValueType(BT_String, getSizeType(sizeof(StringRef)), false, 0);
269 }
270
271 template<>
272 inline ValueType ValueType::getValueType<void*>() {
273 return ValueType(BT_Pointer, getSizeType(sizeof(void*)), false, 0);
274 }
275
276 /// Base class for AST nodes in the typed intermediate language.
277 class SExpr {
278 public:
279 SExpr() = delete;
280
opcode()281 TIL_Opcode opcode() const { return static_cast<TIL_Opcode>(Opcode); }
282
283 // Subclasses of SExpr must define the following:
284 //
285 // This(const This& E, ...) {
286 // copy constructor: construct copy of E, with some additional arguments.
287 // }
288 //
289 // template <class V>
290 // typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
291 // traverse all subexpressions, following the traversal/rewriter interface.
292 // }
293 //
294 // template <class C> typename C::CType compare(CType* E, C& Cmp) {
295 // compare all subexpressions, following the comparator interface
296 // }
new(size_t S,MemRegionRef & R)297 void *operator new(size_t S, MemRegionRef &R) {
298 return ::operator new(S, R);
299 }
300
301 /// SExpr objects must be created in an arena.
302 void *operator new(size_t) = delete;
303
304 /// SExpr objects cannot be deleted.
305 // This declaration is public to workaround a gcc bug that breaks building
306 // with REQUIRES_EH=1.
307 void operator delete(void *) = delete;
308
309 /// Returns the instruction ID for this expression.
310 /// All basic block instructions have a unique ID (i.e. virtual register).
id()311 unsigned id() const { return SExprID; }
312
313 /// Returns the block, if this is an instruction in a basic block,
314 /// otherwise returns null.
block()315 BasicBlock *block() const { return Block; }
316
317 /// Set the basic block and instruction ID for this expression.
setID(BasicBlock * B,unsigned id)318 void setID(BasicBlock *B, unsigned id) { Block = B; SExprID = id; }
319
320 protected:
SExpr(TIL_Opcode Op)321 SExpr(TIL_Opcode Op) : Opcode(Op) {}
SExpr(const SExpr & E)322 SExpr(const SExpr &E) : Opcode(E.Opcode), Flags(E.Flags) {}
323
324 const unsigned char Opcode;
325 unsigned char Reserved = 0;
326 unsigned short Flags = 0;
327 unsigned SExprID = 0;
328 BasicBlock *Block = nullptr;
329 };
330
331 // Contains various helper functions for SExprs.
332 namespace ThreadSafetyTIL {
333
isTrivial(const SExpr * E)334 inline bool isTrivial(const SExpr *E) {
335 unsigned Op = E->opcode();
336 return Op == COP_Variable || Op == COP_Literal || Op == COP_LiteralPtr;
337 }
338
339 } // namespace ThreadSafetyTIL
340
341 // Nodes which declare variables
342
343 /// A named variable, e.g. "x".
344 ///
345 /// There are two distinct places in which a Variable can appear in the AST.
346 /// A variable declaration introduces a new variable, and can occur in 3 places:
347 /// Let-expressions: (Let (x = t) u)
348 /// Functions: (Function (x : t) u)
349 /// Self-applicable functions (SFunction (x) t)
350 ///
351 /// If a variable occurs in any other location, it is a reference to an existing
352 /// variable declaration -- e.g. 'x' in (x * y + z). To save space, we don't
353 /// allocate a separate AST node for variable references; a reference is just a
354 /// pointer to the original declaration.
355 class Variable : public SExpr {
356 public:
357 enum VariableKind {
358 /// Let-variable
359 VK_Let,
360
361 /// Function parameter
362 VK_Fun,
363
364 /// SFunction (self) parameter
365 VK_SFun
366 };
367
368 Variable(StringRef s, SExpr *D = nullptr)
SExpr(COP_Variable)369 : SExpr(COP_Variable), Name(s), Definition(D) {
370 Flags = VK_Let;
371 }
372
373 Variable(SExpr *D, const ValueDecl *Cvd = nullptr)
SExpr(COP_Variable)374 : SExpr(COP_Variable), Name(Cvd ? Cvd->getName() : "_x"),
375 Definition(D), Cvdecl(Cvd) {
376 Flags = VK_Let;
377 }
378
Variable(const Variable & Vd,SExpr * D)379 Variable(const Variable &Vd, SExpr *D) // rewrite constructor
380 : SExpr(Vd), Name(Vd.Name), Definition(D), Cvdecl(Vd.Cvdecl) {
381 Flags = Vd.kind();
382 }
383
classof(const SExpr * E)384 static bool classof(const SExpr *E) { return E->opcode() == COP_Variable; }
385
386 /// Return the kind of variable (let, function param, or self)
kind()387 VariableKind kind() const { return static_cast<VariableKind>(Flags); }
388
389 /// Return the name of the variable, if any.
name()390 StringRef name() const { return Name; }
391
392 /// Return the clang declaration for this variable, if any.
clangDecl()393 const ValueDecl *clangDecl() const { return Cvdecl; }
394
395 /// Return the definition of the variable.
396 /// For let-vars, this is the setting expression.
397 /// For function and self parameters, it is the type of the variable.
definition()398 SExpr *definition() { return Definition; }
definition()399 const SExpr *definition() const { return Definition; }
400
setName(StringRef S)401 void setName(StringRef S) { Name = S; }
setKind(VariableKind K)402 void setKind(VariableKind K) { Flags = K; }
setDefinition(SExpr * E)403 void setDefinition(SExpr *E) { Definition = E; }
setClangDecl(const ValueDecl * VD)404 void setClangDecl(const ValueDecl *VD) { Cvdecl = VD; }
405
406 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)407 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
408 // This routine is only called for variable references.
409 return Vs.reduceVariableRef(this);
410 }
411
412 template <class C>
compare(const Variable * E,C & Cmp)413 typename C::CType compare(const Variable* E, C& Cmp) const {
414 return Cmp.compareVariableRefs(this, E);
415 }
416
417 private:
418 friend class BasicBlock;
419 friend class Function;
420 friend class Let;
421 friend class SFunction;
422
423 // The name of the variable.
424 StringRef Name;
425
426 // The TIL type or definition.
427 SExpr *Definition;
428
429 // The clang declaration for this variable.
430 const ValueDecl *Cvdecl = nullptr;
431 };
432
433 /// Placeholder for an expression that has not yet been created.
434 /// Used to implement lazy copy and rewriting strategies.
435 class Future : public SExpr {
436 public:
437 enum FutureStatus {
438 FS_pending,
439 FS_evaluating,
440 FS_done
441 };
442
Future()443 Future() : SExpr(COP_Future) {}
444 virtual ~Future() = delete;
445
classof(const SExpr * E)446 static bool classof(const SExpr *E) { return E->opcode() == COP_Future; }
447
448 // A lazy rewriting strategy should subclass Future and override this method.
compute()449 virtual SExpr *compute() { return nullptr; }
450
451 // Return the result of this future if it exists, otherwise return null.
maybeGetResult()452 SExpr *maybeGetResult() const { return Result; }
453
454 // Return the result of this future; forcing it if necessary.
result()455 SExpr *result() {
456 switch (Status) {
457 case FS_pending:
458 return force();
459 case FS_evaluating:
460 return nullptr; // infinite loop; illegal recursion.
461 case FS_done:
462 return Result;
463 }
464 }
465
466 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)467 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
468 assert(Result && "Cannot traverse Future that has not been forced.");
469 return Vs.traverse(Result, Ctx);
470 }
471
472 template <class C>
compare(const Future * E,C & Cmp)473 typename C::CType compare(const Future* E, C& Cmp) const {
474 if (!Result || !E->Result)
475 return Cmp.comparePointers(this, E);
476 return Cmp.compare(Result, E->Result);
477 }
478
479 private:
480 SExpr* force();
481
482 FutureStatus Status = FS_pending;
483 SExpr *Result = nullptr;
484 };
485
486 /// Placeholder for expressions that cannot be represented in the TIL.
487 class Undefined : public SExpr {
488 public:
SExpr(COP_Undefined)489 Undefined(const Stmt *S = nullptr) : SExpr(COP_Undefined), Cstmt(S) {}
Undefined(const Undefined & U)490 Undefined(const Undefined &U) : SExpr(U), Cstmt(U.Cstmt) {}
491
classof(const SExpr * E)492 static bool classof(const SExpr *E) { return E->opcode() == COP_Undefined; }
493
494 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)495 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
496 return Vs.reduceUndefined(*this);
497 }
498
499 template <class C>
compare(const Undefined * E,C & Cmp)500 typename C::CType compare(const Undefined* E, C& Cmp) const {
501 return Cmp.trueResult();
502 }
503
504 private:
505 const Stmt *Cstmt;
506 };
507
508 /// Placeholder for a wildcard that matches any other expression.
509 class Wildcard : public SExpr {
510 public:
Wildcard()511 Wildcard() : SExpr(COP_Wildcard) {}
512 Wildcard(const Wildcard &) = default;
513
classof(const SExpr * E)514 static bool classof(const SExpr *E) { return E->opcode() == COP_Wildcard; }
515
traverse(V & Vs,typename V::R_Ctx Ctx)516 template <class V> typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
517 return Vs.reduceWildcard(*this);
518 }
519
520 template <class C>
compare(const Wildcard * E,C & Cmp)521 typename C::CType compare(const Wildcard* E, C& Cmp) const {
522 return Cmp.trueResult();
523 }
524 };
525
526 template <class T> class LiteralT;
527
528 // Base class for literal values.
529 class Literal : public SExpr {
530 public:
Literal(const Expr * C)531 Literal(const Expr *C)
532 : SExpr(COP_Literal), ValType(ValueType::getValueType<void>()), Cexpr(C) {}
Literal(ValueType VT)533 Literal(ValueType VT) : SExpr(COP_Literal), ValType(VT) {}
534 Literal(const Literal &) = default;
535
classof(const SExpr * E)536 static bool classof(const SExpr *E) { return E->opcode() == COP_Literal; }
537
538 // The clang expression for this literal.
clangExpr()539 const Expr *clangExpr() const { return Cexpr; }
540
valueType()541 ValueType valueType() const { return ValType; }
542
as()543 template<class T> const LiteralT<T>& as() const {
544 return *static_cast<const LiteralT<T>*>(this);
545 }
as()546 template<class T> LiteralT<T>& as() {
547 return *static_cast<LiteralT<T>*>(this);
548 }
549
550 template <class V> typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx);
551
552 template <class C>
compare(const Literal * E,C & Cmp)553 typename C::CType compare(const Literal* E, C& Cmp) const {
554 // TODO: defer actual comparison to LiteralT
555 return Cmp.trueResult();
556 }
557
558 private:
559 const ValueType ValType;
560 const Expr *Cexpr = nullptr;
561 };
562
563 // Derived class for literal values, which stores the actual value.
564 template<class T>
565 class LiteralT : public Literal {
566 public:
LiteralT(T Dat)567 LiteralT(T Dat) : Literal(ValueType::getValueType<T>()), Val(Dat) {}
LiteralT(const LiteralT<T> & L)568 LiteralT(const LiteralT<T> &L) : Literal(L), Val(L.Val) {}
569
value()570 T value() const { return Val;}
value()571 T& value() { return Val; }
572
573 private:
574 T Val;
575 };
576
577 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)578 typename V::R_SExpr Literal::traverse(V &Vs, typename V::R_Ctx Ctx) {
579 if (Cexpr)
580 return Vs.reduceLiteral(*this);
581
582 switch (ValType.Base) {
583 case ValueType::BT_Void:
584 break;
585 case ValueType::BT_Bool:
586 return Vs.reduceLiteralT(as<bool>());
587 case ValueType::BT_Int: {
588 switch (ValType.Size) {
589 case ValueType::ST_8:
590 if (ValType.Signed)
591 return Vs.reduceLiteralT(as<int8_t>());
592 else
593 return Vs.reduceLiteralT(as<uint8_t>());
594 case ValueType::ST_16:
595 if (ValType.Signed)
596 return Vs.reduceLiteralT(as<int16_t>());
597 else
598 return Vs.reduceLiteralT(as<uint16_t>());
599 case ValueType::ST_32:
600 if (ValType.Signed)
601 return Vs.reduceLiteralT(as<int32_t>());
602 else
603 return Vs.reduceLiteralT(as<uint32_t>());
604 case ValueType::ST_64:
605 if (ValType.Signed)
606 return Vs.reduceLiteralT(as<int64_t>());
607 else
608 return Vs.reduceLiteralT(as<uint64_t>());
609 default:
610 break;
611 }
612 }
613 case ValueType::BT_Float: {
614 switch (ValType.Size) {
615 case ValueType::ST_32:
616 return Vs.reduceLiteralT(as<float>());
617 case ValueType::ST_64:
618 return Vs.reduceLiteralT(as<double>());
619 default:
620 break;
621 }
622 }
623 case ValueType::BT_String:
624 return Vs.reduceLiteralT(as<StringRef>());
625 case ValueType::BT_Pointer:
626 return Vs.reduceLiteralT(as<void*>());
627 case ValueType::BT_ValueRef:
628 break;
629 }
630 return Vs.reduceLiteral(*this);
631 }
632
633 /// A Literal pointer to an object allocated in memory.
634 /// At compile time, pointer literals are represented by symbolic names.
635 class LiteralPtr : public SExpr {
636 public:
LiteralPtr(const ValueDecl * D)637 LiteralPtr(const ValueDecl *D) : SExpr(COP_LiteralPtr), Cvdecl(D) {}
638 LiteralPtr(const LiteralPtr &) = default;
639
classof(const SExpr * E)640 static bool classof(const SExpr *E) { return E->opcode() == COP_LiteralPtr; }
641
642 // The clang declaration for the value that this pointer points to.
clangDecl()643 const ValueDecl *clangDecl() const { return Cvdecl; }
644
645 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)646 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
647 return Vs.reduceLiteralPtr(*this);
648 }
649
650 template <class C>
compare(const LiteralPtr * E,C & Cmp)651 typename C::CType compare(const LiteralPtr* E, C& Cmp) const {
652 return Cmp.comparePointers(Cvdecl, E->Cvdecl);
653 }
654
655 private:
656 const ValueDecl *Cvdecl;
657 };
658
659 /// A function -- a.k.a. lambda abstraction.
660 /// Functions with multiple arguments are created by currying,
661 /// e.g. (Function (x: Int) (Function (y: Int) (Code { return x + y })))
662 class Function : public SExpr {
663 public:
Function(Variable * Vd,SExpr * Bd)664 Function(Variable *Vd, SExpr *Bd)
665 : SExpr(COP_Function), VarDecl(Vd), Body(Bd) {
666 Vd->setKind(Variable::VK_Fun);
667 }
668
Function(const Function & F,Variable * Vd,SExpr * Bd)669 Function(const Function &F, Variable *Vd, SExpr *Bd) // rewrite constructor
670 : SExpr(F), VarDecl(Vd), Body(Bd) {
671 Vd->setKind(Variable::VK_Fun);
672 }
673
classof(const SExpr * E)674 static bool classof(const SExpr *E) { return E->opcode() == COP_Function; }
675
variableDecl()676 Variable *variableDecl() { return VarDecl; }
variableDecl()677 const Variable *variableDecl() const { return VarDecl; }
678
body()679 SExpr *body() { return Body; }
body()680 const SExpr *body() const { return Body; }
681
682 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)683 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
684 // This is a variable declaration, so traverse the definition.
685 auto E0 = Vs.traverse(VarDecl->Definition, Vs.typeCtx(Ctx));
686 // Tell the rewriter to enter the scope of the function.
687 Variable *Nvd = Vs.enterScope(*VarDecl, E0);
688 auto E1 = Vs.traverse(Body, Vs.declCtx(Ctx));
689 Vs.exitScope(*VarDecl);
690 return Vs.reduceFunction(*this, Nvd, E1);
691 }
692
693 template <class C>
compare(const Function * E,C & Cmp)694 typename C::CType compare(const Function* E, C& Cmp) const {
695 typename C::CType Ct =
696 Cmp.compare(VarDecl->definition(), E->VarDecl->definition());
697 if (Cmp.notTrue(Ct))
698 return Ct;
699 Cmp.enterScope(variableDecl(), E->variableDecl());
700 Ct = Cmp.compare(body(), E->body());
701 Cmp.leaveScope();
702 return Ct;
703 }
704
705 private:
706 Variable *VarDecl;
707 SExpr* Body;
708 };
709
710 /// A self-applicable function.
711 /// A self-applicable function can be applied to itself. It's useful for
712 /// implementing objects and late binding.
713 class SFunction : public SExpr {
714 public:
SFunction(Variable * Vd,SExpr * B)715 SFunction(Variable *Vd, SExpr *B)
716 : SExpr(COP_SFunction), VarDecl(Vd), Body(B) {
717 assert(Vd->Definition == nullptr);
718 Vd->setKind(Variable::VK_SFun);
719 Vd->Definition = this;
720 }
721
SFunction(const SFunction & F,Variable * Vd,SExpr * B)722 SFunction(const SFunction &F, Variable *Vd, SExpr *B) // rewrite constructor
723 : SExpr(F), VarDecl(Vd), Body(B) {
724 assert(Vd->Definition == nullptr);
725 Vd->setKind(Variable::VK_SFun);
726 Vd->Definition = this;
727 }
728
classof(const SExpr * E)729 static bool classof(const SExpr *E) { return E->opcode() == COP_SFunction; }
730
variableDecl()731 Variable *variableDecl() { return VarDecl; }
variableDecl()732 const Variable *variableDecl() const { return VarDecl; }
733
body()734 SExpr *body() { return Body; }
body()735 const SExpr *body() const { return Body; }
736
737 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)738 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
739 // A self-variable points to the SFunction itself.
740 // A rewrite must introduce the variable with a null definition, and update
741 // it after 'this' has been rewritten.
742 Variable *Nvd = Vs.enterScope(*VarDecl, nullptr);
743 auto E1 = Vs.traverse(Body, Vs.declCtx(Ctx));
744 Vs.exitScope(*VarDecl);
745 // A rewrite operation will call SFun constructor to set Vvd->Definition.
746 return Vs.reduceSFunction(*this, Nvd, E1);
747 }
748
749 template <class C>
compare(const SFunction * E,C & Cmp)750 typename C::CType compare(const SFunction* E, C& Cmp) const {
751 Cmp.enterScope(variableDecl(), E->variableDecl());
752 typename C::CType Ct = Cmp.compare(body(), E->body());
753 Cmp.leaveScope();
754 return Ct;
755 }
756
757 private:
758 Variable *VarDecl;
759 SExpr* Body;
760 };
761
762 /// A block of code -- e.g. the body of a function.
763 class Code : public SExpr {
764 public:
Code(SExpr * T,SExpr * B)765 Code(SExpr *T, SExpr *B) : SExpr(COP_Code), ReturnType(T), Body(B) {}
Code(const Code & C,SExpr * T,SExpr * B)766 Code(const Code &C, SExpr *T, SExpr *B) // rewrite constructor
767 : SExpr(C), ReturnType(T), Body(B) {}
768
classof(const SExpr * E)769 static bool classof(const SExpr *E) { return E->opcode() == COP_Code; }
770
returnType()771 SExpr *returnType() { return ReturnType; }
returnType()772 const SExpr *returnType() const { return ReturnType; }
773
body()774 SExpr *body() { return Body; }
body()775 const SExpr *body() const { return Body; }
776
777 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)778 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
779 auto Nt = Vs.traverse(ReturnType, Vs.typeCtx(Ctx));
780 auto Nb = Vs.traverse(Body, Vs.lazyCtx(Ctx));
781 return Vs.reduceCode(*this, Nt, Nb);
782 }
783
784 template <class C>
compare(const Code * E,C & Cmp)785 typename C::CType compare(const Code* E, C& Cmp) const {
786 typename C::CType Ct = Cmp.compare(returnType(), E->returnType());
787 if (Cmp.notTrue(Ct))
788 return Ct;
789 return Cmp.compare(body(), E->body());
790 }
791
792 private:
793 SExpr* ReturnType;
794 SExpr* Body;
795 };
796
797 /// A typed, writable location in memory
798 class Field : public SExpr {
799 public:
Field(SExpr * R,SExpr * B)800 Field(SExpr *R, SExpr *B) : SExpr(COP_Field), Range(R), Body(B) {}
Field(const Field & C,SExpr * R,SExpr * B)801 Field(const Field &C, SExpr *R, SExpr *B) // rewrite constructor
802 : SExpr(C), Range(R), Body(B) {}
803
classof(const SExpr * E)804 static bool classof(const SExpr *E) { return E->opcode() == COP_Field; }
805
range()806 SExpr *range() { return Range; }
range()807 const SExpr *range() const { return Range; }
808
body()809 SExpr *body() { return Body; }
body()810 const SExpr *body() const { return Body; }
811
812 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)813 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
814 auto Nr = Vs.traverse(Range, Vs.typeCtx(Ctx));
815 auto Nb = Vs.traverse(Body, Vs.lazyCtx(Ctx));
816 return Vs.reduceField(*this, Nr, Nb);
817 }
818
819 template <class C>
compare(const Field * E,C & Cmp)820 typename C::CType compare(const Field* E, C& Cmp) const {
821 typename C::CType Ct = Cmp.compare(range(), E->range());
822 if (Cmp.notTrue(Ct))
823 return Ct;
824 return Cmp.compare(body(), E->body());
825 }
826
827 private:
828 SExpr* Range;
829 SExpr* Body;
830 };
831
832 /// Apply an argument to a function.
833 /// Note that this does not actually call the function. Functions are curried,
834 /// so this returns a closure in which the first parameter has been applied.
835 /// Once all parameters have been applied, Call can be used to invoke the
836 /// function.
837 class Apply : public SExpr {
838 public:
Apply(SExpr * F,SExpr * A)839 Apply(SExpr *F, SExpr *A) : SExpr(COP_Apply), Fun(F), Arg(A) {}
Apply(const Apply & A,SExpr * F,SExpr * Ar)840 Apply(const Apply &A, SExpr *F, SExpr *Ar) // rewrite constructor
841 : SExpr(A), Fun(F), Arg(Ar) {}
842
classof(const SExpr * E)843 static bool classof(const SExpr *E) { return E->opcode() == COP_Apply; }
844
fun()845 SExpr *fun() { return Fun; }
fun()846 const SExpr *fun() const { return Fun; }
847
arg()848 SExpr *arg() { return Arg; }
arg()849 const SExpr *arg() const { return Arg; }
850
851 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)852 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
853 auto Nf = Vs.traverse(Fun, Vs.subExprCtx(Ctx));
854 auto Na = Vs.traverse(Arg, Vs.subExprCtx(Ctx));
855 return Vs.reduceApply(*this, Nf, Na);
856 }
857
858 template <class C>
compare(const Apply * E,C & Cmp)859 typename C::CType compare(const Apply* E, C& Cmp) const {
860 typename C::CType Ct = Cmp.compare(fun(), E->fun());
861 if (Cmp.notTrue(Ct))
862 return Ct;
863 return Cmp.compare(arg(), E->arg());
864 }
865
866 private:
867 SExpr* Fun;
868 SExpr* Arg;
869 };
870
871 /// Apply a self-argument to a self-applicable function.
872 class SApply : public SExpr {
873 public:
SExpr(COP_SApply)874 SApply(SExpr *Sf, SExpr *A = nullptr) : SExpr(COP_SApply), Sfun(Sf), Arg(A) {}
875 SApply(SApply &A, SExpr *Sf, SExpr *Ar = nullptr) // rewrite constructor
SExpr(A)876 : SExpr(A), Sfun(Sf), Arg(Ar) {}
877
classof(const SExpr * E)878 static bool classof(const SExpr *E) { return E->opcode() == COP_SApply; }
879
sfun()880 SExpr *sfun() { return Sfun; }
sfun()881 const SExpr *sfun() const { return Sfun; }
882
arg()883 SExpr *arg() { return Arg ? Arg : Sfun; }
arg()884 const SExpr *arg() const { return Arg ? Arg : Sfun; }
885
isDelegation()886 bool isDelegation() const { return Arg != nullptr; }
887
888 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)889 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
890 auto Nf = Vs.traverse(Sfun, Vs.subExprCtx(Ctx));
891 typename V::R_SExpr Na = Arg ? Vs.traverse(Arg, Vs.subExprCtx(Ctx))
892 : nullptr;
893 return Vs.reduceSApply(*this, Nf, Na);
894 }
895
896 template <class C>
compare(const SApply * E,C & Cmp)897 typename C::CType compare(const SApply* E, C& Cmp) const {
898 typename C::CType Ct = Cmp.compare(sfun(), E->sfun());
899 if (Cmp.notTrue(Ct) || (!arg() && !E->arg()))
900 return Ct;
901 return Cmp.compare(arg(), E->arg());
902 }
903
904 private:
905 SExpr* Sfun;
906 SExpr* Arg;
907 };
908
909 /// Project a named slot from a C++ struct or class.
910 class Project : public SExpr {
911 public:
Project(SExpr * R,const ValueDecl * Cvd)912 Project(SExpr *R, const ValueDecl *Cvd)
913 : SExpr(COP_Project), Rec(R), Cvdecl(Cvd) {
914 assert(Cvd && "ValueDecl must not be null");
915 }
916
classof(const SExpr * E)917 static bool classof(const SExpr *E) { return E->opcode() == COP_Project; }
918
record()919 SExpr *record() { return Rec; }
record()920 const SExpr *record() const { return Rec; }
921
clangDecl()922 const ValueDecl *clangDecl() const { return Cvdecl; }
923
isArrow()924 bool isArrow() const { return (Flags & 0x01) != 0; }
925
setArrow(bool b)926 void setArrow(bool b) {
927 if (b) Flags |= 0x01;
928 else Flags &= 0xFFFE;
929 }
930
slotName()931 StringRef slotName() const {
932 if (Cvdecl->getDeclName().isIdentifier())
933 return Cvdecl->getName();
934 if (!SlotName) {
935 SlotName = "";
936 llvm::raw_string_ostream OS(*SlotName);
937 Cvdecl->printName(OS);
938 }
939 return *SlotName;
940 }
941
942 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)943 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
944 auto Nr = Vs.traverse(Rec, Vs.subExprCtx(Ctx));
945 return Vs.reduceProject(*this, Nr);
946 }
947
948 template <class C>
compare(const Project * E,C & Cmp)949 typename C::CType compare(const Project* E, C& Cmp) const {
950 typename C::CType Ct = Cmp.compare(record(), E->record());
951 if (Cmp.notTrue(Ct))
952 return Ct;
953 return Cmp.comparePointers(Cvdecl, E->Cvdecl);
954 }
955
956 private:
957 SExpr* Rec;
958 mutable llvm::Optional<std::string> SlotName;
959 const ValueDecl *Cvdecl;
960 };
961
962 /// Call a function (after all arguments have been applied).
963 class Call : public SExpr {
964 public:
965 Call(SExpr *T, const CallExpr *Ce = nullptr)
SExpr(COP_Call)966 : SExpr(COP_Call), Target(T), Cexpr(Ce) {}
Call(const Call & C,SExpr * T)967 Call(const Call &C, SExpr *T) : SExpr(C), Target(T), Cexpr(C.Cexpr) {}
968
classof(const SExpr * E)969 static bool classof(const SExpr *E) { return E->opcode() == COP_Call; }
970
target()971 SExpr *target() { return Target; }
target()972 const SExpr *target() const { return Target; }
973
clangCallExpr()974 const CallExpr *clangCallExpr() const { return Cexpr; }
975
976 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)977 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
978 auto Nt = Vs.traverse(Target, Vs.subExprCtx(Ctx));
979 return Vs.reduceCall(*this, Nt);
980 }
981
982 template <class C>
compare(const Call * E,C & Cmp)983 typename C::CType compare(const Call* E, C& Cmp) const {
984 return Cmp.compare(target(), E->target());
985 }
986
987 private:
988 SExpr* Target;
989 const CallExpr *Cexpr;
990 };
991
992 /// Allocate memory for a new value on the heap or stack.
993 class Alloc : public SExpr {
994 public:
995 enum AllocKind {
996 AK_Stack,
997 AK_Heap
998 };
999
Alloc(SExpr * D,AllocKind K)1000 Alloc(SExpr *D, AllocKind K) : SExpr(COP_Alloc), Dtype(D) { Flags = K; }
Alloc(const Alloc & A,SExpr * Dt)1001 Alloc(const Alloc &A, SExpr *Dt) : SExpr(A), Dtype(Dt) { Flags = A.kind(); }
1002
classof(const SExpr * E)1003 static bool classof(const SExpr *E) { return E->opcode() == COP_Call; }
1004
kind()1005 AllocKind kind() const { return static_cast<AllocKind>(Flags); }
1006
dataType()1007 SExpr *dataType() { return Dtype; }
dataType()1008 const SExpr *dataType() const { return Dtype; }
1009
1010 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1011 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1012 auto Nd = Vs.traverse(Dtype, Vs.declCtx(Ctx));
1013 return Vs.reduceAlloc(*this, Nd);
1014 }
1015
1016 template <class C>
compare(const Alloc * E,C & Cmp)1017 typename C::CType compare(const Alloc* E, C& Cmp) const {
1018 typename C::CType Ct = Cmp.compareIntegers(kind(), E->kind());
1019 if (Cmp.notTrue(Ct))
1020 return Ct;
1021 return Cmp.compare(dataType(), E->dataType());
1022 }
1023
1024 private:
1025 SExpr* Dtype;
1026 };
1027
1028 /// Load a value from memory.
1029 class Load : public SExpr {
1030 public:
Load(SExpr * P)1031 Load(SExpr *P) : SExpr(COP_Load), Ptr(P) {}
Load(const Load & L,SExpr * P)1032 Load(const Load &L, SExpr *P) : SExpr(L), Ptr(P) {}
1033
classof(const SExpr * E)1034 static bool classof(const SExpr *E) { return E->opcode() == COP_Load; }
1035
pointer()1036 SExpr *pointer() { return Ptr; }
pointer()1037 const SExpr *pointer() const { return Ptr; }
1038
1039 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1040 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1041 auto Np = Vs.traverse(Ptr, Vs.subExprCtx(Ctx));
1042 return Vs.reduceLoad(*this, Np);
1043 }
1044
1045 template <class C>
compare(const Load * E,C & Cmp)1046 typename C::CType compare(const Load* E, C& Cmp) const {
1047 return Cmp.compare(pointer(), E->pointer());
1048 }
1049
1050 private:
1051 SExpr* Ptr;
1052 };
1053
1054 /// Store a value to memory.
1055 /// The destination is a pointer to a field, the source is the value to store.
1056 class Store : public SExpr {
1057 public:
Store(SExpr * P,SExpr * V)1058 Store(SExpr *P, SExpr *V) : SExpr(COP_Store), Dest(P), Source(V) {}
Store(const Store & S,SExpr * P,SExpr * V)1059 Store(const Store &S, SExpr *P, SExpr *V) : SExpr(S), Dest(P), Source(V) {}
1060
classof(const SExpr * E)1061 static bool classof(const SExpr *E) { return E->opcode() == COP_Store; }
1062
destination()1063 SExpr *destination() { return Dest; } // Address to store to
destination()1064 const SExpr *destination() const { return Dest; }
1065
source()1066 SExpr *source() { return Source; } // Value to store
source()1067 const SExpr *source() const { return Source; }
1068
1069 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1070 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1071 auto Np = Vs.traverse(Dest, Vs.subExprCtx(Ctx));
1072 auto Nv = Vs.traverse(Source, Vs.subExprCtx(Ctx));
1073 return Vs.reduceStore(*this, Np, Nv);
1074 }
1075
1076 template <class C>
compare(const Store * E,C & Cmp)1077 typename C::CType compare(const Store* E, C& Cmp) const {
1078 typename C::CType Ct = Cmp.compare(destination(), E->destination());
1079 if (Cmp.notTrue(Ct))
1080 return Ct;
1081 return Cmp.compare(source(), E->source());
1082 }
1083
1084 private:
1085 SExpr* Dest;
1086 SExpr* Source;
1087 };
1088
1089 /// If p is a reference to an array, then p[i] is a reference to the i'th
1090 /// element of the array.
1091 class ArrayIndex : public SExpr {
1092 public:
ArrayIndex(SExpr * A,SExpr * N)1093 ArrayIndex(SExpr *A, SExpr *N) : SExpr(COP_ArrayIndex), Array(A), Index(N) {}
ArrayIndex(const ArrayIndex & E,SExpr * A,SExpr * N)1094 ArrayIndex(const ArrayIndex &E, SExpr *A, SExpr *N)
1095 : SExpr(E), Array(A), Index(N) {}
1096
classof(const SExpr * E)1097 static bool classof(const SExpr *E) { return E->opcode() == COP_ArrayIndex; }
1098
array()1099 SExpr *array() { return Array; }
array()1100 const SExpr *array() const { return Array; }
1101
index()1102 SExpr *index() { return Index; }
index()1103 const SExpr *index() const { return Index; }
1104
1105 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1106 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1107 auto Na = Vs.traverse(Array, Vs.subExprCtx(Ctx));
1108 auto Ni = Vs.traverse(Index, Vs.subExprCtx(Ctx));
1109 return Vs.reduceArrayIndex(*this, Na, Ni);
1110 }
1111
1112 template <class C>
compare(const ArrayIndex * E,C & Cmp)1113 typename C::CType compare(const ArrayIndex* E, C& Cmp) const {
1114 typename C::CType Ct = Cmp.compare(array(), E->array());
1115 if (Cmp.notTrue(Ct))
1116 return Ct;
1117 return Cmp.compare(index(), E->index());
1118 }
1119
1120 private:
1121 SExpr* Array;
1122 SExpr* Index;
1123 };
1124
1125 /// Pointer arithmetic, restricted to arrays only.
1126 /// If p is a reference to an array, then p + n, where n is an integer, is
1127 /// a reference to a subarray.
1128 class ArrayAdd : public SExpr {
1129 public:
ArrayAdd(SExpr * A,SExpr * N)1130 ArrayAdd(SExpr *A, SExpr *N) : SExpr(COP_ArrayAdd), Array(A), Index(N) {}
ArrayAdd(const ArrayAdd & E,SExpr * A,SExpr * N)1131 ArrayAdd(const ArrayAdd &E, SExpr *A, SExpr *N)
1132 : SExpr(E), Array(A), Index(N) {}
1133
classof(const SExpr * E)1134 static bool classof(const SExpr *E) { return E->opcode() == COP_ArrayAdd; }
1135
array()1136 SExpr *array() { return Array; }
array()1137 const SExpr *array() const { return Array; }
1138
index()1139 SExpr *index() { return Index; }
index()1140 const SExpr *index() const { return Index; }
1141
1142 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1143 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1144 auto Na = Vs.traverse(Array, Vs.subExprCtx(Ctx));
1145 auto Ni = Vs.traverse(Index, Vs.subExprCtx(Ctx));
1146 return Vs.reduceArrayAdd(*this, Na, Ni);
1147 }
1148
1149 template <class C>
compare(const ArrayAdd * E,C & Cmp)1150 typename C::CType compare(const ArrayAdd* E, C& Cmp) const {
1151 typename C::CType Ct = Cmp.compare(array(), E->array());
1152 if (Cmp.notTrue(Ct))
1153 return Ct;
1154 return Cmp.compare(index(), E->index());
1155 }
1156
1157 private:
1158 SExpr* Array;
1159 SExpr* Index;
1160 };
1161
1162 /// Simple arithmetic unary operations, e.g. negate and not.
1163 /// These operations have no side-effects.
1164 class UnaryOp : public SExpr {
1165 public:
UnaryOp(TIL_UnaryOpcode Op,SExpr * E)1166 UnaryOp(TIL_UnaryOpcode Op, SExpr *E) : SExpr(COP_UnaryOp), Expr0(E) {
1167 Flags = Op;
1168 }
1169
UnaryOp(const UnaryOp & U,SExpr * E)1170 UnaryOp(const UnaryOp &U, SExpr *E) : SExpr(U), Expr0(E) { Flags = U.Flags; }
1171
classof(const SExpr * E)1172 static bool classof(const SExpr *E) { return E->opcode() == COP_UnaryOp; }
1173
unaryOpcode()1174 TIL_UnaryOpcode unaryOpcode() const {
1175 return static_cast<TIL_UnaryOpcode>(Flags);
1176 }
1177
expr()1178 SExpr *expr() { return Expr0; }
expr()1179 const SExpr *expr() const { return Expr0; }
1180
1181 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1182 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1183 auto Ne = Vs.traverse(Expr0, Vs.subExprCtx(Ctx));
1184 return Vs.reduceUnaryOp(*this, Ne);
1185 }
1186
1187 template <class C>
compare(const UnaryOp * E,C & Cmp)1188 typename C::CType compare(const UnaryOp* E, C& Cmp) const {
1189 typename C::CType Ct =
1190 Cmp.compareIntegers(unaryOpcode(), E->unaryOpcode());
1191 if (Cmp.notTrue(Ct))
1192 return Ct;
1193 return Cmp.compare(expr(), E->expr());
1194 }
1195
1196 private:
1197 SExpr* Expr0;
1198 };
1199
1200 /// Simple arithmetic binary operations, e.g. +, -, etc.
1201 /// These operations have no side effects.
1202 class BinaryOp : public SExpr {
1203 public:
BinaryOp(TIL_BinaryOpcode Op,SExpr * E0,SExpr * E1)1204 BinaryOp(TIL_BinaryOpcode Op, SExpr *E0, SExpr *E1)
1205 : SExpr(COP_BinaryOp), Expr0(E0), Expr1(E1) {
1206 Flags = Op;
1207 }
1208
BinaryOp(const BinaryOp & B,SExpr * E0,SExpr * E1)1209 BinaryOp(const BinaryOp &B, SExpr *E0, SExpr *E1)
1210 : SExpr(B), Expr0(E0), Expr1(E1) {
1211 Flags = B.Flags;
1212 }
1213
classof(const SExpr * E)1214 static bool classof(const SExpr *E) { return E->opcode() == COP_BinaryOp; }
1215
binaryOpcode()1216 TIL_BinaryOpcode binaryOpcode() const {
1217 return static_cast<TIL_BinaryOpcode>(Flags);
1218 }
1219
expr0()1220 SExpr *expr0() { return Expr0; }
expr0()1221 const SExpr *expr0() const { return Expr0; }
1222
expr1()1223 SExpr *expr1() { return Expr1; }
expr1()1224 const SExpr *expr1() const { return Expr1; }
1225
1226 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1227 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1228 auto Ne0 = Vs.traverse(Expr0, Vs.subExprCtx(Ctx));
1229 auto Ne1 = Vs.traverse(Expr1, Vs.subExprCtx(Ctx));
1230 return Vs.reduceBinaryOp(*this, Ne0, Ne1);
1231 }
1232
1233 template <class C>
compare(const BinaryOp * E,C & Cmp)1234 typename C::CType compare(const BinaryOp* E, C& Cmp) const {
1235 typename C::CType Ct =
1236 Cmp.compareIntegers(binaryOpcode(), E->binaryOpcode());
1237 if (Cmp.notTrue(Ct))
1238 return Ct;
1239 Ct = Cmp.compare(expr0(), E->expr0());
1240 if (Cmp.notTrue(Ct))
1241 return Ct;
1242 return Cmp.compare(expr1(), E->expr1());
1243 }
1244
1245 private:
1246 SExpr* Expr0;
1247 SExpr* Expr1;
1248 };
1249
1250 /// Cast expressions.
1251 /// Cast expressions are essentially unary operations, but we treat them
1252 /// as a distinct AST node because they only change the type of the result.
1253 class Cast : public SExpr {
1254 public:
Cast(TIL_CastOpcode Op,SExpr * E)1255 Cast(TIL_CastOpcode Op, SExpr *E) : SExpr(COP_Cast), Expr0(E) { Flags = Op; }
Cast(const Cast & C,SExpr * E)1256 Cast(const Cast &C, SExpr *E) : SExpr(C), Expr0(E) { Flags = C.Flags; }
1257
classof(const SExpr * E)1258 static bool classof(const SExpr *E) { return E->opcode() == COP_Cast; }
1259
castOpcode()1260 TIL_CastOpcode castOpcode() const {
1261 return static_cast<TIL_CastOpcode>(Flags);
1262 }
1263
expr()1264 SExpr *expr() { return Expr0; }
expr()1265 const SExpr *expr() const { return Expr0; }
1266
1267 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1268 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1269 auto Ne = Vs.traverse(Expr0, Vs.subExprCtx(Ctx));
1270 return Vs.reduceCast(*this, Ne);
1271 }
1272
1273 template <class C>
compare(const Cast * E,C & Cmp)1274 typename C::CType compare(const Cast* E, C& Cmp) const {
1275 typename C::CType Ct =
1276 Cmp.compareIntegers(castOpcode(), E->castOpcode());
1277 if (Cmp.notTrue(Ct))
1278 return Ct;
1279 return Cmp.compare(expr(), E->expr());
1280 }
1281
1282 private:
1283 SExpr* Expr0;
1284 };
1285
1286 class SCFG;
1287
1288 /// Phi Node, for code in SSA form.
1289 /// Each Phi node has an array of possible values that it can take,
1290 /// depending on where control flow comes from.
1291 class Phi : public SExpr {
1292 public:
1293 using ValArray = SimpleArray<SExpr *>;
1294
1295 // In minimal SSA form, all Phi nodes are MultiVal.
1296 // During conversion to SSA, incomplete Phi nodes may be introduced, which
1297 // are later determined to be SingleVal, and are thus redundant.
1298 enum Status {
1299 PH_MultiVal = 0, // Phi node has multiple distinct values. (Normal)
1300 PH_SingleVal, // Phi node has one distinct value, and can be eliminated
1301 PH_Incomplete // Phi node is incomplete
1302 };
1303
Phi()1304 Phi() : SExpr(COP_Phi) {}
Phi(MemRegionRef A,unsigned Nvals)1305 Phi(MemRegionRef A, unsigned Nvals) : SExpr(COP_Phi), Values(A, Nvals) {}
Phi(const Phi & P,ValArray && Vs)1306 Phi(const Phi &P, ValArray &&Vs) : SExpr(P), Values(std::move(Vs)) {}
1307
classof(const SExpr * E)1308 static bool classof(const SExpr *E) { return E->opcode() == COP_Phi; }
1309
values()1310 const ValArray &values() const { return Values; }
values()1311 ValArray &values() { return Values; }
1312
status()1313 Status status() const { return static_cast<Status>(Flags); }
setStatus(Status s)1314 void setStatus(Status s) { Flags = s; }
1315
1316 /// Return the clang declaration of the variable for this Phi node, if any.
clangDecl()1317 const ValueDecl *clangDecl() const { return Cvdecl; }
1318
1319 /// Set the clang variable associated with this Phi node.
setClangDecl(const ValueDecl * Cvd)1320 void setClangDecl(const ValueDecl *Cvd) { Cvdecl = Cvd; }
1321
1322 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1323 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1324 typename V::template Container<typename V::R_SExpr>
1325 Nvs(Vs, Values.size());
1326
1327 for (const auto *Val : Values)
1328 Nvs.push_back( Vs.traverse(Val, Vs.subExprCtx(Ctx)) );
1329 return Vs.reducePhi(*this, Nvs);
1330 }
1331
1332 template <class C>
compare(const Phi * E,C & Cmp)1333 typename C::CType compare(const Phi *E, C &Cmp) const {
1334 // TODO: implement CFG comparisons
1335 return Cmp.comparePointers(this, E);
1336 }
1337
1338 private:
1339 ValArray Values;
1340 const ValueDecl* Cvdecl = nullptr;
1341 };
1342
1343 /// Base class for basic block terminators: Branch, Goto, and Return.
1344 class Terminator : public SExpr {
1345 protected:
Terminator(TIL_Opcode Op)1346 Terminator(TIL_Opcode Op) : SExpr(Op) {}
Terminator(const SExpr & E)1347 Terminator(const SExpr &E) : SExpr(E) {}
1348
1349 public:
classof(const SExpr * E)1350 static bool classof(const SExpr *E) {
1351 return E->opcode() >= COP_Goto && E->opcode() <= COP_Return;
1352 }
1353
1354 /// Return the list of basic blocks that this terminator can branch to.
1355 ArrayRef<BasicBlock *> successors();
1356
successors()1357 ArrayRef<BasicBlock *> successors() const {
1358 return const_cast<Terminator*>(this)->successors();
1359 }
1360 };
1361
1362 /// Jump to another basic block.
1363 /// A goto instruction is essentially a tail-recursive call into another
1364 /// block. In addition to the block pointer, it specifies an index into the
1365 /// phi nodes of that block. The index can be used to retrieve the "arguments"
1366 /// of the call.
1367 class Goto : public Terminator {
1368 public:
Goto(BasicBlock * B,unsigned I)1369 Goto(BasicBlock *B, unsigned I)
1370 : Terminator(COP_Goto), TargetBlock(B), Index(I) {}
Goto(const Goto & G,BasicBlock * B,unsigned I)1371 Goto(const Goto &G, BasicBlock *B, unsigned I)
1372 : Terminator(COP_Goto), TargetBlock(B), Index(I) {}
1373
classof(const SExpr * E)1374 static bool classof(const SExpr *E) { return E->opcode() == COP_Goto; }
1375
targetBlock()1376 const BasicBlock *targetBlock() const { return TargetBlock; }
targetBlock()1377 BasicBlock *targetBlock() { return TargetBlock; }
1378
1379 /// Returns the index into the
index()1380 unsigned index() const { return Index; }
1381
1382 /// Return the list of basic blocks that this terminator can branch to.
successors()1383 ArrayRef<BasicBlock *> successors() { return TargetBlock; }
1384
1385 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1386 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1387 BasicBlock *Ntb = Vs.reduceBasicBlockRef(TargetBlock);
1388 return Vs.reduceGoto(*this, Ntb);
1389 }
1390
1391 template <class C>
compare(const Goto * E,C & Cmp)1392 typename C::CType compare(const Goto *E, C &Cmp) const {
1393 // TODO: implement CFG comparisons
1394 return Cmp.comparePointers(this, E);
1395 }
1396
1397 private:
1398 BasicBlock *TargetBlock;
1399 unsigned Index;
1400 };
1401
1402 /// A conditional branch to two other blocks.
1403 /// Note that unlike Goto, Branch does not have an index. The target blocks
1404 /// must be child-blocks, and cannot have Phi nodes.
1405 class Branch : public Terminator {
1406 public:
Branch(SExpr * C,BasicBlock * T,BasicBlock * E)1407 Branch(SExpr *C, BasicBlock *T, BasicBlock *E)
1408 : Terminator(COP_Branch), Condition(C) {
1409 Branches[0] = T;
1410 Branches[1] = E;
1411 }
1412
Branch(const Branch & Br,SExpr * C,BasicBlock * T,BasicBlock * E)1413 Branch(const Branch &Br, SExpr *C, BasicBlock *T, BasicBlock *E)
1414 : Terminator(Br), Condition(C) {
1415 Branches[0] = T;
1416 Branches[1] = E;
1417 }
1418
classof(const SExpr * E)1419 static bool classof(const SExpr *E) { return E->opcode() == COP_Branch; }
1420
condition()1421 const SExpr *condition() const { return Condition; }
condition()1422 SExpr *condition() { return Condition; }
1423
thenBlock()1424 const BasicBlock *thenBlock() const { return Branches[0]; }
thenBlock()1425 BasicBlock *thenBlock() { return Branches[0]; }
1426
elseBlock()1427 const BasicBlock *elseBlock() const { return Branches[1]; }
elseBlock()1428 BasicBlock *elseBlock() { return Branches[1]; }
1429
1430 /// Return the list of basic blocks that this terminator can branch to.
successors()1431 ArrayRef<BasicBlock*> successors() {
1432 return llvm::makeArrayRef(Branches);
1433 }
1434
1435 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1436 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1437 auto Nc = Vs.traverse(Condition, Vs.subExprCtx(Ctx));
1438 BasicBlock *Ntb = Vs.reduceBasicBlockRef(Branches[0]);
1439 BasicBlock *Nte = Vs.reduceBasicBlockRef(Branches[1]);
1440 return Vs.reduceBranch(*this, Nc, Ntb, Nte);
1441 }
1442
1443 template <class C>
compare(const Branch * E,C & Cmp)1444 typename C::CType compare(const Branch *E, C &Cmp) const {
1445 // TODO: implement CFG comparisons
1446 return Cmp.comparePointers(this, E);
1447 }
1448
1449 private:
1450 SExpr *Condition;
1451 BasicBlock *Branches[2];
1452 };
1453
1454 /// Return from the enclosing function, passing the return value to the caller.
1455 /// Only the exit block should end with a return statement.
1456 class Return : public Terminator {
1457 public:
Return(SExpr * Rval)1458 Return(SExpr* Rval) : Terminator(COP_Return), Retval(Rval) {}
Return(const Return & R,SExpr * Rval)1459 Return(const Return &R, SExpr* Rval) : Terminator(R), Retval(Rval) {}
1460
classof(const SExpr * E)1461 static bool classof(const SExpr *E) { return E->opcode() == COP_Return; }
1462
1463 /// Return an empty list.
successors()1464 ArrayRef<BasicBlock *> successors() { return None; }
1465
returnValue()1466 SExpr *returnValue() { return Retval; }
returnValue()1467 const SExpr *returnValue() const { return Retval; }
1468
1469 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1470 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1471 auto Ne = Vs.traverse(Retval, Vs.subExprCtx(Ctx));
1472 return Vs.reduceReturn(*this, Ne);
1473 }
1474
1475 template <class C>
compare(const Return * E,C & Cmp)1476 typename C::CType compare(const Return *E, C &Cmp) const {
1477 return Cmp.compare(Retval, E->Retval);
1478 }
1479
1480 private:
1481 SExpr* Retval;
1482 };
1483
successors()1484 inline ArrayRef<BasicBlock*> Terminator::successors() {
1485 switch (opcode()) {
1486 case COP_Goto: return cast<Goto>(this)->successors();
1487 case COP_Branch: return cast<Branch>(this)->successors();
1488 case COP_Return: return cast<Return>(this)->successors();
1489 default:
1490 return None;
1491 }
1492 }
1493
1494 /// A basic block is part of an SCFG. It can be treated as a function in
1495 /// continuation passing style. A block consists of a sequence of phi nodes,
1496 /// which are "arguments" to the function, followed by a sequence of
1497 /// instructions. It ends with a Terminator, which is a Branch or Goto to
1498 /// another basic block in the same SCFG.
1499 class BasicBlock : public SExpr {
1500 public:
1501 using InstrArray = SimpleArray<SExpr *>;
1502 using BlockArray = SimpleArray<BasicBlock *>;
1503
1504 // TopologyNodes are used to overlay tree structures on top of the CFG,
1505 // such as dominator and postdominator trees. Each block is assigned an
1506 // ID in the tree according to a depth-first search. Tree traversals are
1507 // always up, towards the parents.
1508 struct TopologyNode {
1509 int NodeID = 0;
1510
1511 // Includes this node, so must be > 1.
1512 int SizeOfSubTree = 0;
1513
1514 // Pointer to parent.
1515 BasicBlock *Parent = nullptr;
1516
1517 TopologyNode() = default;
1518
isParentOfTopologyNode1519 bool isParentOf(const TopologyNode& OtherNode) {
1520 return OtherNode.NodeID > NodeID &&
1521 OtherNode.NodeID < NodeID + SizeOfSubTree;
1522 }
1523
isParentOfOrEqualTopologyNode1524 bool isParentOfOrEqual(const TopologyNode& OtherNode) {
1525 return OtherNode.NodeID >= NodeID &&
1526 OtherNode.NodeID < NodeID + SizeOfSubTree;
1527 }
1528 };
1529
BasicBlock(MemRegionRef A)1530 explicit BasicBlock(MemRegionRef A)
1531 : SExpr(COP_BasicBlock), Arena(A), BlockID(0), Visited(false) {}
BasicBlock(BasicBlock & B,MemRegionRef A,InstrArray && As,InstrArray && Is,Terminator * T)1532 BasicBlock(BasicBlock &B, MemRegionRef A, InstrArray &&As, InstrArray &&Is,
1533 Terminator *T)
1534 : SExpr(COP_BasicBlock), Arena(A), BlockID(0), Visited(false),
1535 Args(std::move(As)), Instrs(std::move(Is)), TermInstr(T) {}
1536
classof(const SExpr * E)1537 static bool classof(const SExpr *E) { return E->opcode() == COP_BasicBlock; }
1538
1539 /// Returns the block ID. Every block has a unique ID in the CFG.
blockID()1540 int blockID() const { return BlockID; }
1541
1542 /// Returns the number of predecessors.
numPredecessors()1543 size_t numPredecessors() const { return Predecessors.size(); }
numSuccessors()1544 size_t numSuccessors() const { return successors().size(); }
1545
cfg()1546 const SCFG* cfg() const { return CFGPtr; }
cfg()1547 SCFG* cfg() { return CFGPtr; }
1548
parent()1549 const BasicBlock *parent() const { return DominatorNode.Parent; }
parent()1550 BasicBlock *parent() { return DominatorNode.Parent; }
1551
arguments()1552 const InstrArray &arguments() const { return Args; }
arguments()1553 InstrArray &arguments() { return Args; }
1554
instructions()1555 InstrArray &instructions() { return Instrs; }
instructions()1556 const InstrArray &instructions() const { return Instrs; }
1557
1558 /// Returns a list of predecessors.
1559 /// The order of predecessors in the list is important; each phi node has
1560 /// exactly one argument for each precessor, in the same order.
predecessors()1561 BlockArray &predecessors() { return Predecessors; }
predecessors()1562 const BlockArray &predecessors() const { return Predecessors; }
1563
successors()1564 ArrayRef<BasicBlock*> successors() { return TermInstr->successors(); }
successors()1565 ArrayRef<BasicBlock*> successors() const { return TermInstr->successors(); }
1566
terminator()1567 const Terminator *terminator() const { return TermInstr; }
terminator()1568 Terminator *terminator() { return TermInstr; }
1569
setTerminator(Terminator * E)1570 void setTerminator(Terminator *E) { TermInstr = E; }
1571
Dominates(const BasicBlock & Other)1572 bool Dominates(const BasicBlock &Other) {
1573 return DominatorNode.isParentOfOrEqual(Other.DominatorNode);
1574 }
1575
PostDominates(const BasicBlock & Other)1576 bool PostDominates(const BasicBlock &Other) {
1577 return PostDominatorNode.isParentOfOrEqual(Other.PostDominatorNode);
1578 }
1579
1580 /// Add a new argument.
addArgument(Phi * V)1581 void addArgument(Phi *V) {
1582 Args.reserveCheck(1, Arena);
1583 Args.push_back(V);
1584 }
1585
1586 /// Add a new instruction.
addInstruction(SExpr * V)1587 void addInstruction(SExpr *V) {
1588 Instrs.reserveCheck(1, Arena);
1589 Instrs.push_back(V);
1590 }
1591
1592 // Add a new predecessor, and return the phi-node index for it.
1593 // Will add an argument to all phi-nodes, initialized to nullptr.
1594 unsigned addPredecessor(BasicBlock *Pred);
1595
1596 // Reserve space for Nargs arguments.
reserveArguments(unsigned Nargs)1597 void reserveArguments(unsigned Nargs) { Args.reserve(Nargs, Arena); }
1598
1599 // Reserve space for Nins instructions.
reserveInstructions(unsigned Nins)1600 void reserveInstructions(unsigned Nins) { Instrs.reserve(Nins, Arena); }
1601
1602 // Reserve space for NumPreds predecessors, including space in phi nodes.
1603 void reservePredecessors(unsigned NumPreds);
1604
1605 /// Return the index of BB, or Predecessors.size if BB is not a predecessor.
findPredecessorIndex(const BasicBlock * BB)1606 unsigned findPredecessorIndex(const BasicBlock *BB) const {
1607 auto I = llvm::find(Predecessors, BB);
1608 return std::distance(Predecessors.cbegin(), I);
1609 }
1610
1611 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1612 typename V::R_BasicBlock traverse(V &Vs, typename V::R_Ctx Ctx) {
1613 typename V::template Container<SExpr*> Nas(Vs, Args.size());
1614 typename V::template Container<SExpr*> Nis(Vs, Instrs.size());
1615
1616 // Entering the basic block should do any scope initialization.
1617 Vs.enterBasicBlock(*this);
1618
1619 for (const auto *E : Args) {
1620 auto Ne = Vs.traverse(E, Vs.subExprCtx(Ctx));
1621 Nas.push_back(Ne);
1622 }
1623 for (const auto *E : Instrs) {
1624 auto Ne = Vs.traverse(E, Vs.subExprCtx(Ctx));
1625 Nis.push_back(Ne);
1626 }
1627 auto Nt = Vs.traverse(TermInstr, Ctx);
1628
1629 // Exiting the basic block should handle any scope cleanup.
1630 Vs.exitBasicBlock(*this);
1631
1632 return Vs.reduceBasicBlock(*this, Nas, Nis, Nt);
1633 }
1634
1635 template <class C>
compare(const BasicBlock * E,C & Cmp)1636 typename C::CType compare(const BasicBlock *E, C &Cmp) const {
1637 // TODO: implement CFG comparisons
1638 return Cmp.comparePointers(this, E);
1639 }
1640
1641 private:
1642 friend class SCFG;
1643
1644 // assign unique ids to all instructions
1645 unsigned renumberInstrs(unsigned id);
1646
1647 unsigned topologicalSort(SimpleArray<BasicBlock *> &Blocks, unsigned ID);
1648 unsigned topologicalFinalSort(SimpleArray<BasicBlock *> &Blocks, unsigned ID);
1649 void computeDominator();
1650 void computePostDominator();
1651
1652 // The arena used to allocate this block.
1653 MemRegionRef Arena;
1654
1655 // The CFG that contains this block.
1656 SCFG *CFGPtr = nullptr;
1657
1658 // Unique ID for this BB in the containing CFG. IDs are in topological order.
1659 unsigned BlockID : 31;
1660
1661 // Bit to determine if a block has been visited during a traversal.
1662 bool Visited : 1;
1663
1664 // Predecessor blocks in the CFG.
1665 BlockArray Predecessors;
1666
1667 // Phi nodes. One argument per predecessor.
1668 InstrArray Args;
1669
1670 // Instructions.
1671 InstrArray Instrs;
1672
1673 // Terminating instruction.
1674 Terminator *TermInstr = nullptr;
1675
1676 // The dominator tree.
1677 TopologyNode DominatorNode;
1678
1679 // The post-dominator tree.
1680 TopologyNode PostDominatorNode;
1681 };
1682
1683 /// An SCFG is a control-flow graph. It consists of a set of basic blocks,
1684 /// each of which terminates in a branch to another basic block. There is one
1685 /// entry point, and one exit point.
1686 class SCFG : public SExpr {
1687 public:
1688 using BlockArray = SimpleArray<BasicBlock *>;
1689 using iterator = BlockArray::iterator;
1690 using const_iterator = BlockArray::const_iterator;
1691
SCFG(MemRegionRef A,unsigned Nblocks)1692 SCFG(MemRegionRef A, unsigned Nblocks)
1693 : SExpr(COP_SCFG), Arena(A), Blocks(A, Nblocks) {
1694 Entry = new (A) BasicBlock(A);
1695 Exit = new (A) BasicBlock(A);
1696 auto *V = new (A) Phi();
1697 Exit->addArgument(V);
1698 Exit->setTerminator(new (A) Return(V));
1699 add(Entry);
1700 add(Exit);
1701 }
1702
SCFG(const SCFG & Cfg,BlockArray && Ba)1703 SCFG(const SCFG &Cfg, BlockArray &&Ba) // steals memory from Ba
1704 : SExpr(COP_SCFG), Arena(Cfg.Arena), Blocks(std::move(Ba)) {
1705 // TODO: set entry and exit!
1706 }
1707
classof(const SExpr * E)1708 static bool classof(const SExpr *E) { return E->opcode() == COP_SCFG; }
1709
1710 /// Return true if this CFG is valid.
valid()1711 bool valid() const { return Entry && Exit && Blocks.size() > 0; }
1712
1713 /// Return true if this CFG has been normalized.
1714 /// After normalization, blocks are in topological order, and block and
1715 /// instruction IDs have been assigned.
normal()1716 bool normal() const { return Normal; }
1717
begin()1718 iterator begin() { return Blocks.begin(); }
end()1719 iterator end() { return Blocks.end(); }
1720
begin()1721 const_iterator begin() const { return cbegin(); }
end()1722 const_iterator end() const { return cend(); }
1723
cbegin()1724 const_iterator cbegin() const { return Blocks.cbegin(); }
cend()1725 const_iterator cend() const { return Blocks.cend(); }
1726
entry()1727 const BasicBlock *entry() const { return Entry; }
entry()1728 BasicBlock *entry() { return Entry; }
exit()1729 const BasicBlock *exit() const { return Exit; }
exit()1730 BasicBlock *exit() { return Exit; }
1731
1732 /// Return the number of blocks in the CFG.
1733 /// Block::blockID() will return a number less than numBlocks();
numBlocks()1734 size_t numBlocks() const { return Blocks.size(); }
1735
1736 /// Return the total number of instructions in the CFG.
1737 /// This is useful for building instruction side-tables;
1738 /// A call to SExpr::id() will return a number less than numInstructions().
numInstructions()1739 unsigned numInstructions() { return NumInstructions; }
1740
add(BasicBlock * BB)1741 inline void add(BasicBlock *BB) {
1742 assert(BB->CFGPtr == nullptr);
1743 BB->CFGPtr = this;
1744 Blocks.reserveCheck(1, Arena);
1745 Blocks.push_back(BB);
1746 }
1747
setEntry(BasicBlock * BB)1748 void setEntry(BasicBlock *BB) { Entry = BB; }
setExit(BasicBlock * BB)1749 void setExit(BasicBlock *BB) { Exit = BB; }
1750
1751 void computeNormalForm();
1752
1753 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1754 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1755 Vs.enterCFG(*this);
1756 typename V::template Container<BasicBlock *> Bbs(Vs, Blocks.size());
1757
1758 for (const auto *B : Blocks) {
1759 Bbs.push_back( B->traverse(Vs, Vs.subExprCtx(Ctx)) );
1760 }
1761 Vs.exitCFG(*this);
1762 return Vs.reduceSCFG(*this, Bbs);
1763 }
1764
1765 template <class C>
compare(const SCFG * E,C & Cmp)1766 typename C::CType compare(const SCFG *E, C &Cmp) const {
1767 // TODO: implement CFG comparisons
1768 return Cmp.comparePointers(this, E);
1769 }
1770
1771 private:
1772 // assign unique ids to all instructions
1773 void renumberInstrs();
1774
1775 MemRegionRef Arena;
1776 BlockArray Blocks;
1777 BasicBlock *Entry = nullptr;
1778 BasicBlock *Exit = nullptr;
1779 unsigned NumInstructions = 0;
1780 bool Normal = false;
1781 };
1782
1783 /// An identifier, e.g. 'foo' or 'x'.
1784 /// This is a pseduo-term; it will be lowered to a variable or projection.
1785 class Identifier : public SExpr {
1786 public:
Identifier(StringRef Id)1787 Identifier(StringRef Id): SExpr(COP_Identifier), Name(Id) {}
1788 Identifier(const Identifier &) = default;
1789
classof(const SExpr * E)1790 static bool classof(const SExpr *E) { return E->opcode() == COP_Identifier; }
1791
name()1792 StringRef name() const { return Name; }
1793
1794 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1795 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1796 return Vs.reduceIdentifier(*this);
1797 }
1798
1799 template <class C>
compare(const Identifier * E,C & Cmp)1800 typename C::CType compare(const Identifier* E, C& Cmp) const {
1801 return Cmp.compareStrings(name(), E->name());
1802 }
1803
1804 private:
1805 StringRef Name;
1806 };
1807
1808 /// An if-then-else expression.
1809 /// This is a pseduo-term; it will be lowered to a branch in a CFG.
1810 class IfThenElse : public SExpr {
1811 public:
IfThenElse(SExpr * C,SExpr * T,SExpr * E)1812 IfThenElse(SExpr *C, SExpr *T, SExpr *E)
1813 : SExpr(COP_IfThenElse), Condition(C), ThenExpr(T), ElseExpr(E) {}
IfThenElse(const IfThenElse & I,SExpr * C,SExpr * T,SExpr * E)1814 IfThenElse(const IfThenElse &I, SExpr *C, SExpr *T, SExpr *E)
1815 : SExpr(I), Condition(C), ThenExpr(T), ElseExpr(E) {}
1816
classof(const SExpr * E)1817 static bool classof(const SExpr *E) { return E->opcode() == COP_IfThenElse; }
1818
condition()1819 SExpr *condition() { return Condition; } // Address to store to
condition()1820 const SExpr *condition() const { return Condition; }
1821
thenExpr()1822 SExpr *thenExpr() { return ThenExpr; } // Value to store
thenExpr()1823 const SExpr *thenExpr() const { return ThenExpr; }
1824
elseExpr()1825 SExpr *elseExpr() { return ElseExpr; } // Value to store
elseExpr()1826 const SExpr *elseExpr() const { return ElseExpr; }
1827
1828 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1829 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1830 auto Nc = Vs.traverse(Condition, Vs.subExprCtx(Ctx));
1831 auto Nt = Vs.traverse(ThenExpr, Vs.subExprCtx(Ctx));
1832 auto Ne = Vs.traverse(ElseExpr, Vs.subExprCtx(Ctx));
1833 return Vs.reduceIfThenElse(*this, Nc, Nt, Ne);
1834 }
1835
1836 template <class C>
compare(const IfThenElse * E,C & Cmp)1837 typename C::CType compare(const IfThenElse* E, C& Cmp) const {
1838 typename C::CType Ct = Cmp.compare(condition(), E->condition());
1839 if (Cmp.notTrue(Ct))
1840 return Ct;
1841 Ct = Cmp.compare(thenExpr(), E->thenExpr());
1842 if (Cmp.notTrue(Ct))
1843 return Ct;
1844 return Cmp.compare(elseExpr(), E->elseExpr());
1845 }
1846
1847 private:
1848 SExpr* Condition;
1849 SExpr* ThenExpr;
1850 SExpr* ElseExpr;
1851 };
1852
1853 /// A let-expression, e.g. let x=t; u.
1854 /// This is a pseduo-term; it will be lowered to instructions in a CFG.
1855 class Let : public SExpr {
1856 public:
Let(Variable * Vd,SExpr * Bd)1857 Let(Variable *Vd, SExpr *Bd) : SExpr(COP_Let), VarDecl(Vd), Body(Bd) {
1858 Vd->setKind(Variable::VK_Let);
1859 }
1860
Let(const Let & L,Variable * Vd,SExpr * Bd)1861 Let(const Let &L, Variable *Vd, SExpr *Bd) : SExpr(L), VarDecl(Vd), Body(Bd) {
1862 Vd->setKind(Variable::VK_Let);
1863 }
1864
classof(const SExpr * E)1865 static bool classof(const SExpr *E) { return E->opcode() == COP_Let; }
1866
variableDecl()1867 Variable *variableDecl() { return VarDecl; }
variableDecl()1868 const Variable *variableDecl() const { return VarDecl; }
1869
body()1870 SExpr *body() { return Body; }
body()1871 const SExpr *body() const { return Body; }
1872
1873 template <class V>
traverse(V & Vs,typename V::R_Ctx Ctx)1874 typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
1875 // This is a variable declaration, so traverse the definition.
1876 auto E0 = Vs.traverse(VarDecl->Definition, Vs.subExprCtx(Ctx));
1877 // Tell the rewriter to enter the scope of the let variable.
1878 Variable *Nvd = Vs.enterScope(*VarDecl, E0);
1879 auto E1 = Vs.traverse(Body, Ctx);
1880 Vs.exitScope(*VarDecl);
1881 return Vs.reduceLet(*this, Nvd, E1);
1882 }
1883
1884 template <class C>
compare(const Let * E,C & Cmp)1885 typename C::CType compare(const Let* E, C& Cmp) const {
1886 typename C::CType Ct =
1887 Cmp.compare(VarDecl->definition(), E->VarDecl->definition());
1888 if (Cmp.notTrue(Ct))
1889 return Ct;
1890 Cmp.enterScope(variableDecl(), E->variableDecl());
1891 Ct = Cmp.compare(body(), E->body());
1892 Cmp.leaveScope();
1893 return Ct;
1894 }
1895
1896 private:
1897 Variable *VarDecl;
1898 SExpr* Body;
1899 };
1900
1901 const SExpr *getCanonicalVal(const SExpr *E);
1902 SExpr* simplifyToCanonicalVal(SExpr *E);
1903 void simplifyIncompleteArg(til::Phi *Ph);
1904
1905 } // namespace til
1906 } // namespace threadSafety
1907
1908 } // namespace clang
1909
1910 #endif // LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYTIL_H
1911