23 #include "llvm/ADT/STLExtras.h" 24 #include "llvm/ADT/SmallString.h" 25 #include "llvm/Support/raw_ostream.h" 27 using namespace clang;
31 class VLASizeChecker :
public Checker< check::PreStmt<DeclStmt> > {
32 mutable std::unique_ptr<BugType> BT;
33 enum VLASize_Kind { VLA_Garbage, VLA_Zero, VLA_Tainted, VLA_Negative };
37 std::unique_ptr<BugReporterVisitor> Visitor =
nullptr)
const;
44 void VLASizeChecker::reportBug(
46 CheckerContext &C, std::unique_ptr<BugReporterVisitor> Visitor)
const {
54 this,
"Dangerous variable-length array (VLA) declaration"));
57 llvm::raw_svector_ostream os(buf);
58 os <<
"Declared variable-length array (VLA) ";
61 os <<
"uses a garbage value as its size";
64 os <<
"has zero size";
67 os <<
"has tainted size";
70 os <<
"has negative size";
74 auto report = llvm::make_unique<BugReport>(*BT, os.str(), N);
75 report->addVisitor(std::move(Visitor));
77 bugreporter::trackNullOrUndefValue(N, SizeE, *report);
100 reportBug(VLA_Garbage, SE, state, C);
110 if (state->isTainted(sizeV)) {
111 reportBug(VLA_Tainted, SE,
nullptr, C,
112 llvm::make_unique<TaintBugVisitor>(sizeV));
120 std::tie(stateNotZero, stateZero) = state->assume(sizeD);
122 if (stateZero && !stateNotZero) {
123 reportBug(VLA_Zero, SE, stateZero, C);
128 state = stateNotZero;
140 SVal LessThanZeroVal = svalBuilder.
evalBinOp(state, BO_LT, sizeD, Zero, Ty);
146 std::tie(StateNeg, StatePos) = CM.
assumeDual(state, *LessThanZeroDVal);
147 if (StateNeg && !StatePos) {
148 reportBug(VLA_Negative, SE, state, C);
165 state, BO_Mul, ArrayLength, EleSizeVal.
castAs<
NonLoc>(), SizeTy);
170 state->getRegion(VD, LC)->getExtent(svalBuilder);
173 svalBuilder.
evalEQ(state, Extent, ArraySize);
174 state = state->assume(sizeIsKnown,
true);
nonloc::ConcreteInt makeIntVal(const IntegerLiteral *integer)
A (possibly-)qualified type.
ExplodedNode * generateErrorNode(ProgramStateRef State=nullptr, const ProgramPointTag *Tag=nullptr)
Generate a transition to a node that will be used to report an error.
ExplodedNode * addTransition(ProgramStateRef State=nullptr, const ProgramPointTag *Tag=nullptr)
Generates a new transition in the program state graph (ExplodedGraph).
SVal evalCast(SVal val, QualType castTy, QualType originalType)
QualType getElementType() const
Represents a variable declaration or definition.
SVal getSVal(const Stmt *S) const
Get the value of arbitrary expressions at this point in the path.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
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
CharUnits - This is an opaque type for sizes expressed in character units.
Expr * getSizeExpr() const
ProgramStatePair assumeDual(ProgramStateRef State, DefinedSVal Cond)
Returns a pair of states (StTrue, StFalse) where the given condition is assumed to be true or false...
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
DefinedOrUnknownSVal makeZeroVal(QualType type)
Construct an SVal representing '0' for the specified type.
Expr - This represents one expression.
SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, SVal lhs, SVal rhs, QualType type)
Optional< T > getAs() const
Convert to the specified SVal type, returning None if this SVal is not of the desired type...
CHECKER * registerChecker(AT... Args)
Used to register checkers.
ConstraintManager & getConstraintManager()
void emitReport(std::unique_ptr< BugReport > R)
Emit the diagnostics report.
DeclStmt - Adaptor class for mixing declarations with statements and expressions. ...
SVal - This represents a symbolic expression, which can be either an L-value or an R-value...
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.
Dataflow Directional Tag Classes.
ASTContext & getASTContext()
SVal evalEQ(ProgramStateRef state, SVal lhs, SVal rhs)
const Decl * getSingleDecl() const
bool isSingleDecl() const
isSingleDecl - This method returns true if this DeclStmt refers to a single Decl. ...
T castAs() const
Convert to the specified SVal type, asserting that this SVal is of the desired type.
const ProgramStateRef & getState() const
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
SValBuilder & getSValBuilder()
const VariableArrayType * getAsVariableArrayType(QualType T) const
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
Represents a C array with a specified size that is not an integer-constant-expression.
const LocationContext * getLocationContext() const
CanQualType getSizeType() const
Return the unique type for "size_t" (C99 7.17), defined in <stddef.h>.