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SValBuilder.h
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1 // SValBuilder.h - Construction of SVals from evaluating expressions -*- C++ -*-
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines SValBuilder, a class that defines the interface for
11 // "symbolical evaluators" which construct an SVal from an expression.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SVALBUILDER_H
16 #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SVALBUILDER_H
17 
18 #include "clang/AST/ASTContext.h"
20 #include "clang/AST/Expr.h"
21 #include "clang/AST/ExprObjC.h"
22 #include "clang/AST/Type.h"
23 #include "clang/Basic/LLVM.h"
31 #include "llvm/ADT/ImmutableList.h"
32 #include "llvm/ADT/Optional.h"
33 #include <cstdint>
34 
35 namespace clang {
36 
37 class BlockDecl;
38 class CXXBoolLiteralExpr;
39 class CXXMethodDecl;
40 class CXXRecordDecl;
41 class DeclaratorDecl;
42 class FunctionDecl;
43 class LocationContext;
44 class StackFrameContext;
45 class Stmt;
46 
47 namespace ento {
48 
49 class ConditionTruthVal;
50 class ProgramStateManager;
51 class StoreRef;
52 
53 class SValBuilder {
54  virtual void anchor();
55 
56 protected:
58 
59  /// Manager of APSInt values.
61 
62  /// Manages the creation of symbols.
64 
65  /// Manages the creation of memory regions.
67 
69 
70  /// The scalar type to use for array indices.
72 
73  /// The width of the scalar type used for array indices.
74  const unsigned ArrayIndexWidth;
75 
76  virtual SVal evalCastFromNonLoc(NonLoc val, QualType castTy) = 0;
77  virtual SVal evalCastFromLoc(Loc val, QualType castTy) = 0;
78 
79 public:
80  // FIXME: Make these protected again once RegionStoreManager correctly
81  // handles loads from different bound value types.
82  virtual SVal dispatchCast(SVal val, QualType castTy) = 0;
83 
84 public:
85  SValBuilder(llvm::BumpPtrAllocator &alloc, ASTContext &context,
86  ProgramStateManager &stateMgr)
87  : Context(context), BasicVals(context, alloc),
88  SymMgr(context, BasicVals, alloc), MemMgr(context, alloc),
89  StateMgr(stateMgr), ArrayIndexTy(context.LongLongTy),
90  ArrayIndexWidth(context.getTypeSize(ArrayIndexTy)) {}
91 
92  virtual ~SValBuilder() = default;
93 
94  bool haveSameType(const SymExpr *Sym1, const SymExpr *Sym2) {
95  return haveSameType(Sym1->getType(), Sym2->getType());
96  }
97 
98  bool haveSameType(QualType Ty1, QualType Ty2) {
99  // FIXME: Remove the second disjunct when we support symbolic
100  // truncation/extension.
101  return (Context.getCanonicalType(Ty1) == Context.getCanonicalType(Ty2) ||
102  (Ty1->isIntegralOrEnumerationType() &&
104  }
105 
106  SVal evalCast(SVal val, QualType castTy, QualType originalType);
107 
108  // Handles casts of type CK_IntegralCast.
110  QualType originalType);
111 
112  virtual SVal evalMinus(NonLoc val) = 0;
113 
114  virtual SVal evalComplement(NonLoc val) = 0;
115 
116  /// Create a new value which represents a binary expression with two non-
117  /// location operands.
119  NonLoc lhs, NonLoc rhs, QualType resultTy) = 0;
120 
121  /// Create a new value which represents a binary expression with two memory
122  /// location operands.
124  Loc lhs, Loc rhs, QualType resultTy) = 0;
125 
126  /// Create a new value which represents a binary expression with a memory
127  /// location and non-location operands. For example, this would be used to
128  /// evaluate a pointer arithmetic operation.
130  Loc lhs, NonLoc rhs, QualType resultTy) = 0;
131 
132  /// Evaluates a given SVal. If the SVal has only one possible (integer) value,
133  /// that value is returned. Otherwise, returns NULL.
134  virtual const llvm::APSInt *getKnownValue(ProgramStateRef state, SVal val) = 0;
135 
136  /// Simplify symbolic expressions within a given SVal. Return an SVal
137  /// that represents the same value, but is hopefully easier to work with
138  /// than the original SVal.
139  virtual SVal simplifySVal(ProgramStateRef State, SVal Val) = 0;
140 
141  /// Constructs a symbolic expression for two non-location values.
143  NonLoc lhs, NonLoc rhs, QualType resultTy);
144 
146  SVal lhs, SVal rhs, QualType type);
147 
148  /// \return Whether values in \p lhs and \p rhs are equal at \p state.
150 
151  SVal evalEQ(ProgramStateRef state, SVal lhs, SVal rhs);
152 
155 
157  const ASTContext &getContext() const { return Context; }
158 
160 
162  return Context.getLangOpts().CPlusPlus ? Context.BoolTy : Context.IntTy;
163  }
164 
166  return ArrayIndexTy;
167  }
168 
171 
173  const SymbolManager &getSymbolManager() const { return SymMgr; }
174 
176  const MemRegionManager &getRegionManager() const { return MemMgr; }
177 
178  // Forwarding methods to SymbolManager.
179 
181  const LocationContext *LCtx,
182  QualType type,
183  unsigned visitCount,
184  const void *symbolTag = nullptr) {
185  return SymMgr.conjureSymbol(stmt, LCtx, type, visitCount, symbolTag);
186  }
187 
189  const LocationContext *LCtx,
190  unsigned visitCount,
191  const void *symbolTag = nullptr) {
192  return SymMgr.conjureSymbol(expr, LCtx, visitCount, symbolTag);
193  }
194 
195  /// Construct an SVal representing '0' for the specified type.
197 
198  /// Make a unique symbol for value of region.
200 
201  /// Create a new symbol with a unique 'name'.
202  ///
203  /// We resort to conjured symbols when we cannot construct a derived symbol.
204  /// The advantage of symbols derived/built from other symbols is that we
205  /// preserve the relation between related(or even equivalent) expressions, so
206  /// conjured symbols should be used sparingly.
207  DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag,
208  const Expr *expr,
209  const LocationContext *LCtx,
210  unsigned count);
211  DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag,
212  const Expr *expr,
213  const LocationContext *LCtx,
214  QualType type,
215  unsigned count);
217  const LocationContext *LCtx,
218  QualType type,
219  unsigned visitCount);
220 
221  /// Conjure a symbol representing heap allocated memory region.
222  ///
223  /// Note, the expression should represent a location.
225  const LocationContext *LCtx,
226  unsigned Count);
227 
229  SymbolRef parentSymbol, const TypedValueRegion *region);
230 
231  DefinedSVal getMetadataSymbolVal(const void *symbolTag,
232  const MemRegion *region,
233  const Expr *expr, QualType type,
234  const LocationContext *LCtx,
235  unsigned count);
236 
238 
240 
241  DefinedSVal getBlockPointer(const BlockDecl *block, CanQualType locTy,
242  const LocationContext *locContext,
243  unsigned blockCount);
244 
245  /// Returns the value of \p E, if it can be determined in a non-path-sensitive
246  /// manner.
247  ///
248  /// If \p E is not a constant or cannot be modeled, returns \c None.
250 
251  NonLoc makeCompoundVal(QualType type, llvm::ImmutableList<SVal> vals) {
252  return nonloc::CompoundVal(BasicVals.getCompoundValData(type, vals));
253  }
254 
256  const TypedValueRegion *region) {
258  BasicVals.getLazyCompoundValData(store, region));
259  }
260 
262  return nonloc::PointerToMember(DD);
263  }
264 
266  return nonloc::PointerToMember(PTMD);
267  }
268 
270  return nonloc::ConcreteInt(BasicVals.getValue(0, ArrayIndexTy));
271  }
272 
273  NonLoc makeArrayIndex(uint64_t idx) {
274  return nonloc::ConcreteInt(BasicVals.getValue(idx, ArrayIndexTy));
275  }
276 
278 
280  return nonloc::ConcreteInt(
281  BasicVals.getValue(integer->getValue(),
283  }
284 
286  return makeTruthVal(boolean->getValue(), boolean->getType());
287  }
288 
290 
291  nonloc::ConcreteInt makeIntVal(const llvm::APSInt& integer) {
292  return nonloc::ConcreteInt(BasicVals.getValue(integer));
293  }
294 
295  loc::ConcreteInt makeIntLocVal(const llvm::APSInt &integer) {
296  return loc::ConcreteInt(BasicVals.getValue(integer));
297  }
298 
299  NonLoc makeIntVal(const llvm::APInt& integer, bool isUnsigned) {
300  return nonloc::ConcreteInt(BasicVals.getValue(integer, isUnsigned));
301  }
302 
303  DefinedSVal makeIntVal(uint64_t integer, QualType type) {
304  if (Loc::isLocType(type))
305  return loc::ConcreteInt(BasicVals.getValue(integer, type));
306 
307  return nonloc::ConcreteInt(BasicVals.getValue(integer, type));
308  }
309 
310  NonLoc makeIntVal(uint64_t integer, bool isUnsigned) {
311  return nonloc::ConcreteInt(BasicVals.getIntValue(integer, isUnsigned));
312  }
313 
314  NonLoc makeIntValWithPtrWidth(uint64_t integer, bool isUnsigned) {
315  return nonloc::ConcreteInt(
316  BasicVals.getIntWithPtrWidth(integer, isUnsigned));
317  }
318 
319  NonLoc makeLocAsInteger(Loc loc, unsigned bits) {
320  return nonloc::LocAsInteger(BasicVals.getPersistentSValWithData(loc, bits));
321  }
322 
324  const llvm::APSInt& rhs, QualType type);
325 
326  NonLoc makeNonLoc(const llvm::APSInt& rhs, BinaryOperator::Opcode op,
327  const SymExpr *lhs, QualType type);
328 
330  const SymExpr *rhs, QualType type);
331 
332  /// Create a NonLoc value for cast.
333  NonLoc makeNonLoc(const SymExpr *operand, QualType fromTy, QualType toTy);
334 
336  return nonloc::ConcreteInt(BasicVals.getTruthValue(b, type));
337  }
338 
340  return nonloc::ConcreteInt(BasicVals.getTruthValue(b));
341  }
342 
343  /// Create NULL pointer, with proper pointer bit-width for given address
344  /// space.
345  /// \param type pointer type.
347  return loc::ConcreteInt(BasicVals.getZeroWithTypeSize(type));
348  }
349 
351  return loc::ConcreteInt(BasicVals.getZeroWithPtrWidth());
352  }
353 
355  return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym));
356  }
357 
358  Loc makeLoc(const MemRegion* region) {
359  return loc::MemRegionVal(region);
360  }
361 
362  Loc makeLoc(const AddrLabelExpr *expr) {
363  return loc::GotoLabel(expr->getLabel());
364  }
365 
366  Loc makeLoc(const llvm::APSInt& integer) {
367  return loc::ConcreteInt(BasicVals.getValue(integer));
368  }
369 
370  /// Return a memory region for the 'this' object reference.
372  const StackFrameContext *SFC);
373 
374  /// Return a memory region for the 'this' object reference.
376  const StackFrameContext *SFC);
377 };
378 
379 SValBuilder* createSimpleSValBuilder(llvm::BumpPtrAllocator &alloc,
380  ASTContext &context,
381  ProgramStateManager &stateMgr);
382 
383 } // namespace ento
384 
385 } // namespace clang
386 
387 #endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SVALBUILDER_H
Defines the clang::ASTContext interface.
Represents a function declaration or definition.
Definition: Decl.h:1714
bool getValue() const
Definition: ExprObjC.h:94
TypedValueRegion - An abstract class representing regions having a typed value.
Definition: MemRegion.h:525
nonloc::ConcreteInt makeIntVal(const IntegerLiteral *integer)
Definition: SValBuilder.h:279
DefinedSVal getBlockPointer(const BlockDecl *block, CanQualType locTy, const LocationContext *locContext, unsigned blockCount)
SymbolManager & getSymbolManager()
Definition: SValBuilder.h:172
QualType getArrayIndexType() const
Definition: SValBuilder.h:165
A (possibly-)qualified type.
Definition: Type.h:654
MemRegion - The root abstract class for all memory regions.
Definition: MemRegion.h:94
bool isUnsignedIntegerOrEnumerationType() const
Determines whether this is an integer type that is unsigned or an enumeration types whose underlying ...
Definition: Type.cpp:1863
const internal::VariadicAllOfMatcher< Stmt > stmt
Matches statements.
const CompoundValData * getCompoundValData(QualType T, llvm::ImmutableList< SVal > Vals)
SValBuilder * createSimpleSValBuilder(llvm::BumpPtrAllocator &alloc, ASTContext &context, ProgramStateManager &stateMgr)
Stmt - This represents one statement.
Definition: Stmt.h:66
C Language Family Type Representation.
SVal makeSymExprValNN(ProgramStateRef state, BinaryOperator::Opcode op, NonLoc lhs, NonLoc rhs, QualType resultTy)
Constructs a symbolic expression for two non-location values.
ProgramStateManager & StateMgr
Definition: SValBuilder.h:68
const llvm::APSInt & getZeroWithTypeSize(QualType T)
virtual SVal simplifySVal(ProgramStateRef State, SVal Val)=0
Simplify symbolic expressions within a given SVal.
SVal evalCast(SVal val, QualType castTy, QualType originalType)
Value representing integer constant.
Definition: SVals.h:374
MemRegionManager MemMgr
Manages the creation of memory regions.
Definition: SValBuilder.h:66
const llvm::APSInt & getTruthValue(bool b, QualType T)
const internal::VariadicDynCastAllOfMatcher< Stmt, Expr > expr
Matches expressions.
virtual SVal dispatchCast(SVal val, QualType castTy)=0
loc::MemRegionVal getCXXThis(const CXXMethodDecl *D, const StackFrameContext *SFC)
Return a memory region for the &#39;this&#39; object reference.
NonLoc makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op, const llvm::APSInt &rhs, QualType type)
Definition: SValBuilder.cpp:66
NonLoc makeArrayIndex(uint64_t idx)
Definition: SValBuilder.h:273
BasicValueFactory BasicVals
Manager of APSInt values.
Definition: SValBuilder.h:60
Symbolic value.
Definition: SymExpr.h:30
virtual SVal evalCastFromNonLoc(NonLoc val, QualType castTy)=0
virtual SVal evalBinOpLN(ProgramStateRef state, BinaryOperator::Opcode op, Loc lhs, NonLoc rhs, QualType resultTy)=0
Create a new value which represents a binary expression with a memory location and non-location opera...
MemRegionManager & getRegionManager()
Definition: SValBuilder.h:175
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:150
LineState State
SVal evalIntegralCast(ProgramStateRef state, SVal val, QualType castTy, QualType originalType)
Loc makeNullWithType(QualType type)
Create NULL pointer, with proper pointer bit-width for given address space.
Definition: SValBuilder.h:346
DefinedOrUnknownSVal getDerivedRegionValueSymbolVal(SymbolRef parentSymbol, const TypedValueRegion *region)
i32 captured_struct **param SharedsTy A type which contains references the shared variables *param Shareds Context with the list of shared variables from the p *TaskFunction *param Data Additional data for task generation like final * state
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6311
const SymbolicRegion * getSymbolicRegion(SymbolRef Sym)
Retrieve or create a "symbolic" memory region.
Definition: MemRegion.cpp:993
static bool isLocType(QualType T)
Definition: SVals.h:327
BinaryOperatorKind
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
NonLoc makePointerToMember(const DeclaratorDecl *DD)
Definition: SValBuilder.h:261
DefinedOrUnknownSVal getRegionValueSymbolVal(const TypedValueRegion *region)
Make a unique symbol for value of region.
Loc makeLoc(const MemRegion *region)
Definition: SValBuilder.h:358
Loc makeLoc(const AddrLabelExpr *expr)
Definition: SValBuilder.h:362
loc::ConcreteInt makeIntLocVal(const llvm::APSInt &integer)
Definition: SValBuilder.h:295
NonLoc makeCompoundVal(QualType type, llvm::ImmutableList< SVal > vals)
Definition: SValBuilder.h:251
DefinedSVal getFunctionPointer(const FunctionDecl *func)
NonLoc makeIntValWithPtrWidth(uint64_t integer, bool isUnsigned)
Definition: SValBuilder.h:314
bool haveSameType(QualType Ty1, QualType Ty2)
Definition: SValBuilder.h:98
const llvm::APSInt & getIntValue(uint64_t X, bool isUnsigned)
virtual QualType getType() const =0
Represents a ValueDecl that came out of a declarator.
Definition: Decl.h:688
nonloc::ConcreteInt makeBoolVal(const ObjCBoolLiteralExpr *boolean)
Definition: SValBuilder.h:285
ConditionTruthVal areEqual(ProgramStateRef state, SVal lhs, SVal rhs)
Loc makeLoc(SymbolRef sym)
Definition: SValBuilder.h:354
DefinedOrUnknownSVal makeZeroVal(QualType type)
Construct an SVal representing &#39;0&#39; for the specified type.
Definition: SValBuilder.cpp:51
Pepresents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3838
Expr - This represents one expression.
Definition: Expr.h:106
Defines the clang::LangOptions interface.
virtual SVal evalMinus(NonLoc val)=0
const llvm::APSInt & getIntWithPtrWidth(uint64_t X, bool isUnsigned)
nonloc::ConcreteInt makeTruthVal(bool b)
Definition: SValBuilder.h:339
const QualType ArrayIndexTy
The scalar type to use for array indices.
Definition: SValBuilder.h:71
QualType getConditionType() const
Definition: SValBuilder.h:161
QualType getType() const
Definition: Expr.h:128
virtual SVal evalBinOpLL(ProgramStateRef state, BinaryOperator::Opcode op, Loc lhs, Loc rhs, QualType resultTy)=0
Create a new value which represents a binary expression with two memory location operands.
SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, SVal lhs, SVal rhs, QualType type)
const BasicValueFactory & getBasicValueFactory() const
Definition: SValBuilder.h:170
nonloc::ConcreteInt makeIntVal(const llvm::APSInt &integer)
Definition: SValBuilder.h:291
NonLoc makeIntVal(uint64_t integer, bool isUnsigned)
Definition: SValBuilder.h:310
SymbolManager SymMgr
Manages the creation of symbols.
Definition: SValBuilder.h:63
DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag, const Expr *expr, const LocationContext *LCtx, unsigned count)
Create a new symbol with a unique &#39;name&#39;.
virtual SVal evalCastFromLoc(Loc val, QualType castTy)=0
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2016
ASTContext & getContext()
Definition: SValBuilder.h:156
SVal - This represents a symbolic expression, which can be either an L-value or an R-value...
Definition: SVals.h:76
const llvm::APSInt & getZeroWithPtrWidth(bool isUnsigned=true)
DefinedOrUnknownSVal getConjuredHeapSymbolVal(const Expr *E, const LocationContext *LCtx, unsigned Count)
Conjure a symbol representing heap allocated memory region.
A symbol representing the result of an expression in the case when we do not know anything about what...
Definition: SymbolManager.h:76
virtual SVal evalBinOpNN(ProgramStateRef state, BinaryOperator::Opcode op, NonLoc lhs, NonLoc rhs, QualType resultTy)=0
Create a new value which represents a binary expression with two non- location operands.
const unsigned ArrayIndexWidth
The width of the scalar type used for array indices.
Definition: SValBuilder.h:74
const MemRegionManager & getRegionManager() const
Definition: SValBuilder.h:176
AddrLabelExpr - The GNU address of label extension, representing &&label.
Definition: Expr.h:3483
Dataflow Directional Tag Classes.
NonLoc makeIntVal(const llvm::APInt &integer, bool isUnsigned)
Definition: SValBuilder.h:299
const SymbolConjured * conjureSymbol(const Stmt *stmt, const LocationContext *LCtx, QualType type, unsigned visitCount, const void *symbolTag=nullptr)
Definition: SValBuilder.h:180
NonLoc makeLocAsInteger(Loc loc, unsigned bits)
Definition: SValBuilder.h:319
ProgramStateManager & getStateManager()
Definition: SValBuilder.h:159
SVal evalEQ(ProgramStateRef state, SVal lhs, SVal rhs)
SVal convertToArrayIndex(SVal val)
Definition: SValBuilder.cpp:98
const SymbolConjured * conjureSymbol(const Stmt *E, const LocationContext *LCtx, QualType T, unsigned VisitCount, const void *SymbolTag=nullptr)
DefinedSVal getMetadataSymbolVal(const void *symbolTag, const MemRegion *region, const Expr *expr, QualType type, const LocationContext *LCtx, unsigned count)
llvm::APInt getValue() const
Definition: Expr.h:1295
LabelDecl * getLabel() const
Definition: Expr.h:3505
BasicValueFactory & getBasicValueFactory()
Definition: SValBuilder.h:169
Loc makeLoc(const llvm::APSInt &integer)
Definition: SValBuilder.h:366
DefinedSVal getMemberPointer(const DeclaratorDecl *DD)
SValBuilder(llvm::BumpPtrAllocator &alloc, ASTContext &context, ProgramStateManager &stateMgr)
Definition: SValBuilder.h:85
const std::pair< SVal, uintptr_t > & getPersistentSValWithData(const SVal &V, uintptr_t Data)
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2193
bool haveSameType(const SymExpr *Sym1, const SymExpr *Sym2)
Definition: SValBuilder.h:94
const LazyCompoundValData * getLazyCompoundValData(const StoreRef &store, const TypedValueRegion *region)
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
virtual SVal evalComplement(NonLoc val)=0
Optional< SVal > getConstantVal(const Expr *E)
Returns the value of E, if it can be determined in a non-path-sensitive manner.
const SymbolConjured * conjureSymbol(const Expr *expr, const LocationContext *LCtx, unsigned visitCount, const void *symbolTag=nullptr)
Definition: SValBuilder.h:188
virtual ~SValBuilder()=default
virtual const llvm::APSInt * getKnownValue(ProgramStateRef state, SVal val)=0
Evaluates a given SVal.
CanQualType IntTy
Definition: ASTContext.h:1006
ObjCBoolLiteralExpr - Objective-C Boolean Literal.
Definition: ExprObjC.h:82
NonLoc makePointerToMember(const PointerToMemberData *PTMD)
Definition: SValBuilder.h:265
const ASTContext & getContext() const
Definition: SValBuilder.h:157
nonloc::ConcreteInt makeTruthVal(bool b, QualType type)
Definition: SValBuilder.h:335
DefinedSVal makeIntVal(uint64_t integer, QualType type)
Definition: SValBuilder.h:303
NonLoc makeLazyCompoundVal(const StoreRef &store, const TypedValueRegion *region)
Definition: SValBuilder.h:255
A boolean literal, per ([C++ lex.bool] Boolean literals).
Definition: ExprCXX.h:530
CanQualType BoolTy
Definition: ASTContext.h:998
const SymbolManager & getSymbolManager() const
Definition: SValBuilder.h:173
const LangOptions & getLangOpts() const
Definition: ASTContext.h:689