forked from OSchip/llvm-project
421 lines
12 KiB
C++
421 lines
12 KiB
C++
//== SymbolManager.h - Management of Symbolic Values ------------*- C++ -*--==//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines SymbolManager, a class that manages symbolic values
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// created for use by ExprEngine and related classes.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
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#include "clang/Analysis/Analyses/LiveVariables.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace clang;
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using namespace ento;
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void SymExpr::dump() const {
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dumpToStream(llvm::errs());
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}
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static void print(raw_ostream &os, BinaryOperator::Opcode Op) {
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switch (Op) {
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default:
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llvm_unreachable("operator printing not implemented");
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case BO_Mul: os << '*' ; break;
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case BO_Div: os << '/' ; break;
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case BO_Rem: os << '%' ; break;
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case BO_Add: os << '+' ; break;
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case BO_Sub: os << '-' ; break;
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case BO_Shl: os << "<<" ; break;
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case BO_Shr: os << ">>" ; break;
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case BO_LT: os << "<" ; break;
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case BO_GT: os << '>' ; break;
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case BO_LE: os << "<=" ; break;
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case BO_GE: os << ">=" ; break;
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case BO_EQ: os << "==" ; break;
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case BO_NE: os << "!=" ; break;
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case BO_And: os << '&' ; break;
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case BO_Xor: os << '^' ; break;
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case BO_Or: os << '|' ; break;
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}
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}
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void SymIntExpr::dumpToStream(raw_ostream &os) const {
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os << '(';
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getLHS()->dumpToStream(os);
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os << ") ";
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print(os, getOpcode());
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os << ' ' << getRHS().getZExtValue();
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if (getRHS().isUnsigned()) os << 'U';
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}
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void SymSymExpr::dumpToStream(raw_ostream &os) const {
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os << '(';
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getLHS()->dumpToStream(os);
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os << ") ";
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os << '(';
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getRHS()->dumpToStream(os);
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os << ')';
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}
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void SymbolConjured::dumpToStream(raw_ostream &os) const {
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os << "conj_$" << getSymbolID() << '{' << T.getAsString() << '}';
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}
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void SymbolDerived::dumpToStream(raw_ostream &os) const {
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os << "derived_$" << getSymbolID() << '{'
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<< getParentSymbol() << ',' << getRegion() << '}';
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}
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void SymbolExtent::dumpToStream(raw_ostream &os) const {
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os << "extent_$" << getSymbolID() << '{' << getRegion() << '}';
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}
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void SymbolMetadata::dumpToStream(raw_ostream &os) const {
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os << "meta_$" << getSymbolID() << '{'
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<< getRegion() << ',' << T.getAsString() << '}';
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}
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void SymbolRegionValue::dumpToStream(raw_ostream &os) const {
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os << "reg_$" << getSymbolID() << "<" << R << ">";
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}
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const SymbolRegionValue*
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SymbolManager::getRegionValueSymbol(const TypedValueRegion* R) {
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llvm::FoldingSetNodeID profile;
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SymbolRegionValue::Profile(profile, R);
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void *InsertPos;
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SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
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if (!SD) {
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SD = (SymExpr*) BPAlloc.Allocate<SymbolRegionValue>();
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new (SD) SymbolRegionValue(SymbolCounter, R);
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DataSet.InsertNode(SD, InsertPos);
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++SymbolCounter;
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}
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return cast<SymbolRegionValue>(SD);
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}
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const SymbolConjured*
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SymbolManager::getConjuredSymbol(const Stmt *E, QualType T, unsigned Count,
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const void *SymbolTag) {
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llvm::FoldingSetNodeID profile;
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SymbolConjured::Profile(profile, E, T, Count, SymbolTag);
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void *InsertPos;
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SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
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if (!SD) {
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SD = (SymExpr*) BPAlloc.Allocate<SymbolConjured>();
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new (SD) SymbolConjured(SymbolCounter, E, T, Count, SymbolTag);
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DataSet.InsertNode(SD, InsertPos);
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++SymbolCounter;
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}
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return cast<SymbolConjured>(SD);
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}
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const SymbolDerived*
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SymbolManager::getDerivedSymbol(SymbolRef parentSymbol,
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const TypedValueRegion *R) {
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llvm::FoldingSetNodeID profile;
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SymbolDerived::Profile(profile, parentSymbol, R);
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void *InsertPos;
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SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
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if (!SD) {
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SD = (SymExpr*) BPAlloc.Allocate<SymbolDerived>();
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new (SD) SymbolDerived(SymbolCounter, parentSymbol, R);
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DataSet.InsertNode(SD, InsertPos);
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++SymbolCounter;
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}
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return cast<SymbolDerived>(SD);
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}
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const SymbolExtent*
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SymbolManager::getExtentSymbol(const SubRegion *R) {
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llvm::FoldingSetNodeID profile;
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SymbolExtent::Profile(profile, R);
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void *InsertPos;
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SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
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if (!SD) {
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SD = (SymExpr*) BPAlloc.Allocate<SymbolExtent>();
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new (SD) SymbolExtent(SymbolCounter, R);
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DataSet.InsertNode(SD, InsertPos);
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++SymbolCounter;
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}
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return cast<SymbolExtent>(SD);
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}
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const SymbolMetadata*
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SymbolManager::getMetadataSymbol(const MemRegion* R, const Stmt *S, QualType T,
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unsigned Count, const void *SymbolTag) {
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llvm::FoldingSetNodeID profile;
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SymbolMetadata::Profile(profile, R, S, T, Count, SymbolTag);
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void *InsertPos;
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SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
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if (!SD) {
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SD = (SymExpr*) BPAlloc.Allocate<SymbolMetadata>();
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new (SD) SymbolMetadata(SymbolCounter, R, S, T, Count, SymbolTag);
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DataSet.InsertNode(SD, InsertPos);
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++SymbolCounter;
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}
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return cast<SymbolMetadata>(SD);
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}
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const SymIntExpr *SymbolManager::getSymIntExpr(const SymExpr *lhs,
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BinaryOperator::Opcode op,
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const llvm::APSInt& v,
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QualType t) {
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llvm::FoldingSetNodeID ID;
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SymIntExpr::Profile(ID, lhs, op, v, t);
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void *InsertPos;
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SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
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if (!data) {
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data = (SymIntExpr*) BPAlloc.Allocate<SymIntExpr>();
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new (data) SymIntExpr(lhs, op, v, t);
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DataSet.InsertNode(data, InsertPos);
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}
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return cast<SymIntExpr>(data);
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}
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const SymSymExpr *SymbolManager::getSymSymExpr(const SymExpr *lhs,
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BinaryOperator::Opcode op,
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const SymExpr *rhs,
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QualType t) {
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llvm::FoldingSetNodeID ID;
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SymSymExpr::Profile(ID, lhs, op, rhs, t);
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void *InsertPos;
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SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
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if (!data) {
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data = (SymSymExpr*) BPAlloc.Allocate<SymSymExpr>();
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new (data) SymSymExpr(lhs, op, rhs, t);
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DataSet.InsertNode(data, InsertPos);
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}
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return cast<SymSymExpr>(data);
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}
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QualType SymbolConjured::getType(ASTContext&) const {
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return T;
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}
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QualType SymbolDerived::getType(ASTContext &Ctx) const {
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return R->getValueType();
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}
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QualType SymbolExtent::getType(ASTContext &Ctx) const {
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return Ctx.getSizeType();
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}
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QualType SymbolMetadata::getType(ASTContext&) const {
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return T;
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}
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QualType SymbolRegionValue::getType(ASTContext &C) const {
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return R->getValueType();
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}
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SymbolManager::~SymbolManager() {
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for (SymbolDependTy::const_iterator I = SymbolDependencies.begin(),
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E = SymbolDependencies.end(); I != E; ++I) {
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delete I->second;
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}
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}
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bool SymbolManager::canSymbolicate(QualType T) {
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T = T.getCanonicalType();
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if (Loc::isLocType(T))
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return true;
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if (T->isIntegerType())
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return T->isScalarType();
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if (T->isRecordType() && !T->isUnionType())
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return true;
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return false;
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}
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void SymbolManager::addSymbolDependency(const SymbolRef Primary,
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const SymbolRef Dependent) {
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SymbolDependTy::iterator I = SymbolDependencies.find(Primary);
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SymbolRefSmallVectorTy *dependencies = 0;
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if (I == SymbolDependencies.end()) {
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dependencies = new SymbolRefSmallVectorTy();
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SymbolDependencies[Primary] = dependencies;
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} else {
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dependencies = I->second;
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}
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dependencies->push_back(Dependent);
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}
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const SymbolRefSmallVectorTy *SymbolManager::getDependentSymbols(
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const SymbolRef Primary) {
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SymbolDependTy::const_iterator I = SymbolDependencies.find(Primary);
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if (I == SymbolDependencies.end())
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return 0;
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return I->second;
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}
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void SymbolReaper::markDependentsLive(SymbolRef sym) {
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// Do not mark dependents more then once.
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SymbolMapTy::iterator LI = TheLiving.find(sym);
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assert(LI != TheLiving.end() && "The primary symbol is not live.");
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if (LI->second == HaveMarkedDependents)
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return;
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LI->second = HaveMarkedDependents;
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if (const SymbolRefSmallVectorTy *Deps = SymMgr.getDependentSymbols(sym)) {
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for (SymbolRefSmallVectorTy::const_iterator I = Deps->begin(),
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E = Deps->end(); I != E; ++I) {
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if (TheLiving.find(*I) != TheLiving.end())
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continue;
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markLive(*I);
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}
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}
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}
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void SymbolReaper::markLive(SymbolRef sym) {
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TheLiving[sym] = NotProcessed;
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TheDead.erase(sym);
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markDependentsLive(sym);
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}
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void SymbolReaper::markLive(const MemRegion *region) {
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RegionRoots.insert(region);
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}
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void SymbolReaper::markInUse(SymbolRef sym) {
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if (isa<SymbolMetadata>(sym))
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MetadataInUse.insert(sym);
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}
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bool SymbolReaper::maybeDead(SymbolRef sym) {
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if (isLive(sym))
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return false;
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TheDead.insert(sym);
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return true;
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}
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bool SymbolReaper::isLiveRegion(const MemRegion *MR) {
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if (RegionRoots.count(MR))
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return true;
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MR = MR->getBaseRegion();
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if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR))
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return isLive(SR->getSymbol());
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if (const VarRegion *VR = dyn_cast<VarRegion>(MR))
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return isLive(VR, true);
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// FIXME: This is a gross over-approximation. What we really need is a way to
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// tell if anything still refers to this region. Unlike SymbolicRegions,
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// AllocaRegions don't have associated symbols, though, so we don't actually
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// have a way to track their liveness.
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if (isa<AllocaRegion>(MR))
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return true;
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if (isa<CXXThisRegion>(MR))
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return true;
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if (isa<MemSpaceRegion>(MR))
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return true;
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return false;
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}
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bool SymbolReaper::isLive(SymbolRef sym) {
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if (TheLiving.count(sym)) {
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markDependentsLive(sym);
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return true;
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}
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if (const SymbolDerived *derived = dyn_cast<SymbolDerived>(sym)) {
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if (isLive(derived->getParentSymbol())) {
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markLive(sym);
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return true;
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}
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return false;
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}
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if (const SymbolExtent *extent = dyn_cast<SymbolExtent>(sym)) {
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if (isLiveRegion(extent->getRegion())) {
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markLive(sym);
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return true;
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}
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return false;
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}
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if (const SymbolMetadata *metadata = dyn_cast<SymbolMetadata>(sym)) {
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if (MetadataInUse.count(sym)) {
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if (isLiveRegion(metadata->getRegion())) {
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markLive(sym);
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MetadataInUse.erase(sym);
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return true;
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}
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}
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return false;
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}
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// Interogate the symbol. It may derive from an input value to
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// the analyzed function/method.
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return isa<SymbolRegionValue>(sym);
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}
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bool SymbolReaper::isLive(const Stmt *ExprVal) const {
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return LCtx->getAnalysis<RelaxedLiveVariables>()->isLive(Loc, ExprVal);
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}
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bool SymbolReaper::isLive(const VarRegion *VR, bool includeStoreBindings) const{
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const StackFrameContext *VarContext = VR->getStackFrame();
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const StackFrameContext *CurrentContext = LCtx->getCurrentStackFrame();
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if (VarContext == CurrentContext) {
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if (LCtx->getAnalysis<RelaxedLiveVariables>()->isLive(Loc, VR->getDecl()))
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return true;
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if (!includeStoreBindings)
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return false;
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unsigned &cachedQuery =
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const_cast<SymbolReaper*>(this)->includedRegionCache[VR];
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if (cachedQuery) {
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return cachedQuery == 1;
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}
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// Query the store to see if the region occurs in any live bindings.
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if (Store store = reapedStore.getStore()) {
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bool hasRegion =
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reapedStore.getStoreManager().includedInBindings(store, VR);
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cachedQuery = hasRegion ? 1 : 2;
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return hasRegion;
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}
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return false;
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}
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return VarContext->isParentOf(CurrentContext);
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}
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SymbolVisitor::~SymbolVisitor() {}
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