blob: f20924604f64914df8ceafb46d194f55689120fd [file] [log] [blame]
//===- AnalysisDeclContext.cpp - Analysis context for Path Sens analysis --===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines AnalysisDeclContext, a class that manages the analysis
// context data for path sensitive analysis.
//
//===----------------------------------------------------------------------===//
#include "clang/Analysis/AnalysisDeclContext.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclBase.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Expr.h"
#include "clang/AST/LambdaCapture.h"
#include "clang/AST/ParentMap.h"
#include "clang/AST/PrettyPrinter.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
#include "clang/Analysis/BodyFarm.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/CFGStmtMap.h"
#include "clang/Analysis/Support/BumpVector.h"
#include "clang/Basic/JsonSupport.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <memory>
using namespace clang;
using ManagedAnalysisMap = llvm::DenseMap<const void *, std::unique_ptr<ManagedAnalysis>>;
AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *ADCMgr,
const Decl *D,
const CFG::BuildOptions &Options)
: ADCMgr(ADCMgr), D(D), cfgBuildOptions(Options) {
cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
}
AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *ADCMgr,
const Decl *D)
: ADCMgr(ADCMgr), D(D) {
cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
}
AnalysisDeclContextManager::AnalysisDeclContextManager(
ASTContext &ASTCtx, bool useUnoptimizedCFG, bool addImplicitDtors,
bool addInitializers, bool addTemporaryDtors, bool addLifetime,
bool addLoopExit, bool addScopes, bool synthesizeBodies,
bool addStaticInitBranch, bool addCXXNewAllocator,
bool addRichCXXConstructors, bool markElidedCXXConstructors,
bool addVirtualBaseBranches, CodeInjector *injector)
: Injector(injector), FunctionBodyFarm(ASTCtx, injector),
SynthesizeBodies(synthesizeBodies) {
cfgBuildOptions.PruneTriviallyFalseEdges = !useUnoptimizedCFG;
cfgBuildOptions.AddImplicitDtors = addImplicitDtors;
cfgBuildOptions.AddInitializers = addInitializers;
cfgBuildOptions.AddTemporaryDtors = addTemporaryDtors;
cfgBuildOptions.AddLifetime = addLifetime;
cfgBuildOptions.AddLoopExit = addLoopExit;
cfgBuildOptions.AddScopes = addScopes;
cfgBuildOptions.AddStaticInitBranches = addStaticInitBranch;
cfgBuildOptions.AddCXXNewAllocator = addCXXNewAllocator;
cfgBuildOptions.AddRichCXXConstructors = addRichCXXConstructors;
cfgBuildOptions.MarkElidedCXXConstructors = markElidedCXXConstructors;
cfgBuildOptions.AddVirtualBaseBranches = addVirtualBaseBranches;
}
void AnalysisDeclContextManager::clear() { Contexts.clear(); }
Stmt *AnalysisDeclContext::getBody(bool &IsAutosynthesized) const {
IsAutosynthesized = false;
if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
Stmt *Body = FD->getBody();
if (auto *CoroBody = dyn_cast_or_null<CoroutineBodyStmt>(Body))
Body = CoroBody->getBody();
if (ADCMgr && ADCMgr->synthesizeBodies()) {
Stmt *SynthesizedBody = ADCMgr->getBodyFarm().getBody(FD);
if (SynthesizedBody) {
Body = SynthesizedBody;
IsAutosynthesized = true;
}
}
return Body;
}
else if (const auto *MD = dyn_cast<ObjCMethodDecl>(D)) {
Stmt *Body = MD->getBody();
if (ADCMgr && ADCMgr->synthesizeBodies()) {
Stmt *SynthesizedBody = ADCMgr->getBodyFarm().getBody(MD);
if (SynthesizedBody) {
Body = SynthesizedBody;
IsAutosynthesized = true;
}
}
return Body;
} else if (const auto *BD = dyn_cast<BlockDecl>(D))
return BD->getBody();
else if (const auto *FunTmpl = dyn_cast_or_null<FunctionTemplateDecl>(D))
return FunTmpl->getTemplatedDecl()->getBody();
llvm_unreachable("unknown code decl");
}
Stmt *AnalysisDeclContext::getBody() const {
bool Tmp;
return getBody(Tmp);
}
bool AnalysisDeclContext::isBodyAutosynthesized() const {
bool Tmp;
getBody(Tmp);
return Tmp;
}
bool AnalysisDeclContext::isBodyAutosynthesizedFromModelFile() const {
bool Tmp;
Stmt *Body = getBody(Tmp);
return Tmp && Body->getBeginLoc().isValid();
}
/// Returns true if \param VD is an Objective-C implicit 'self' parameter.
static bool isSelfDecl(const VarDecl *VD) {
return isa<ImplicitParamDecl>(VD) && VD->getName() == "self";
}
const ImplicitParamDecl *AnalysisDeclContext::getSelfDecl() const {
if (const auto *MD = dyn_cast<ObjCMethodDecl>(D))
return MD->getSelfDecl();
if (const auto *BD = dyn_cast<BlockDecl>(D)) {
// See if 'self' was captured by the block.
for (const auto &I : BD->captures()) {
const VarDecl *VD = I.getVariable();
if (isSelfDecl(VD))
return dyn_cast<ImplicitParamDecl>(VD);
}
}
auto *CXXMethod = dyn_cast<CXXMethodDecl>(D);
if (!CXXMethod)
return nullptr;
const CXXRecordDecl *parent = CXXMethod->getParent();
if (!parent->isLambda())
return nullptr;
for (const auto &LC : parent->captures()) {
if (!LC.capturesVariable())
continue;
VarDecl *VD = LC.getCapturedVar();
if (isSelfDecl(VD))
return dyn_cast<ImplicitParamDecl>(VD);
}
return nullptr;
}
void AnalysisDeclContext::registerForcedBlockExpression(const Stmt *stmt) {
if (!forcedBlkExprs)
forcedBlkExprs = new CFG::BuildOptions::ForcedBlkExprs();
// Default construct an entry for 'stmt'.
if (const auto *e = dyn_cast<Expr>(stmt))
stmt = e->IgnoreParens();
(void) (*forcedBlkExprs)[stmt];
}
const CFGBlock *
AnalysisDeclContext::getBlockForRegisteredExpression(const Stmt *stmt) {
assert(forcedBlkExprs);
if (const auto *e = dyn_cast<Expr>(stmt))
stmt = e->IgnoreParens();
CFG::BuildOptions::ForcedBlkExprs::const_iterator itr =
forcedBlkExprs->find(stmt);
assert(itr != forcedBlkExprs->end());
return itr->second;
}
/// Add each synthetic statement in the CFG to the parent map, using the
/// source statement's parent.
static void addParentsForSyntheticStmts(const CFG *TheCFG, ParentMap &PM) {
if (!TheCFG)
return;
for (CFG::synthetic_stmt_iterator I = TheCFG->synthetic_stmt_begin(),
E = TheCFG->synthetic_stmt_end();
I != E; ++I) {
PM.setParent(I->first, PM.getParent(I->second));
}
}
CFG *AnalysisDeclContext::getCFG() {
if (!cfgBuildOptions.PruneTriviallyFalseEdges)
return getUnoptimizedCFG();
if (!builtCFG) {
cfg = CFG::buildCFG(D, getBody(), &D->getASTContext(), cfgBuildOptions);
// Even when the cfg is not successfully built, we don't
// want to try building it again.
builtCFG = true;
if (PM)
addParentsForSyntheticStmts(cfg.get(), *PM);
// The Observer should only observe one build of the CFG.
getCFGBuildOptions().Observer = nullptr;
}
return cfg.get();
}
CFG *AnalysisDeclContext::getUnoptimizedCFG() {
if (!builtCompleteCFG) {
SaveAndRestore<bool> NotPrune(cfgBuildOptions.PruneTriviallyFalseEdges,
false);
completeCFG =
CFG::buildCFG(D, getBody(), &D->getASTContext(), cfgBuildOptions);
// Even when the cfg is not successfully built, we don't
// want to try building it again.
builtCompleteCFG = true;
if (PM)
addParentsForSyntheticStmts(completeCFG.get(), *PM);
// The Observer should only observe one build of the CFG.
getCFGBuildOptions().Observer = nullptr;
}
return completeCFG.get();
}
CFGStmtMap *AnalysisDeclContext::getCFGStmtMap() {
if (cfgStmtMap)
return cfgStmtMap.get();
if (CFG *c = getCFG()) {
cfgStmtMap.reset(CFGStmtMap::Build(c, &getParentMap()));
return cfgStmtMap.get();
}
return nullptr;
}
CFGReverseBlockReachabilityAnalysis *AnalysisDeclContext::getCFGReachablityAnalysis() {
if (CFA)
return CFA.get();
if (CFG *c = getCFG()) {
CFA.reset(new CFGReverseBlockReachabilityAnalysis(*c));
return CFA.get();
}
return nullptr;
}
void AnalysisDeclContext::dumpCFG(bool ShowColors) {
getCFG()->dump(getASTContext().getLangOpts(), ShowColors);
}
ParentMap &AnalysisDeclContext::getParentMap() {
if (!PM) {
PM.reset(new ParentMap(getBody()));
if (const auto *C = dyn_cast<CXXConstructorDecl>(getDecl())) {
for (const auto *I : C->inits()) {
PM->addStmt(I->getInit());
}
}
if (builtCFG)
addParentsForSyntheticStmts(getCFG(), *PM);
if (builtCompleteCFG)
addParentsForSyntheticStmts(getUnoptimizedCFG(), *PM);
}
return *PM;
}
AnalysisDeclContext *AnalysisDeclContextManager::getContext(const Decl *D) {
if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
// Calling 'hasBody' replaces 'FD' in place with the FunctionDecl
// that has the body.
FD->hasBody(FD);
D = FD;
}
std::unique_ptr<AnalysisDeclContext> &AC = Contexts[D];
if (!AC)
AC = std::make_unique<AnalysisDeclContext>(this, D, cfgBuildOptions);
return AC.get();
}
BodyFarm &AnalysisDeclContextManager::getBodyFarm() { return FunctionBodyFarm; }
const StackFrameContext *
AnalysisDeclContext::getStackFrame(const LocationContext *ParentLC,
const Stmt *S, const CFGBlock *Blk,
unsigned BlockCount, unsigned Index) {
return getLocationContextManager().getStackFrame(this, ParentLC, S, Blk,
BlockCount, Index);
}
const BlockInvocationContext *AnalysisDeclContext::getBlockInvocationContext(
const LocationContext *ParentLC, const BlockDecl *BD, const void *Data) {
return getLocationContextManager().getBlockInvocationContext(this, ParentLC,
BD, Data);
}
bool AnalysisDeclContext::isInStdNamespace(const Decl *D) {
const DeclContext *DC = D->getDeclContext()->getEnclosingNamespaceContext();
const auto *ND = dyn_cast<NamespaceDecl>(DC);
if (!ND)
return false;
while (const DeclContext *Parent = ND->getParent()) {
if (!isa<NamespaceDecl>(Parent))
break;
ND = cast<NamespaceDecl>(Parent);
}
return ND->isStdNamespace();
}
std::string AnalysisDeclContext::getFunctionName(const Decl *D) {
std::string Str;
llvm::raw_string_ostream OS(Str);
const ASTContext &Ctx = D->getASTContext();
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
OS << FD->getQualifiedNameAsString();
// In C++, there are overloads.
if (Ctx.getLangOpts().CPlusPlus) {
OS << '(';
for (const auto &P : FD->parameters()) {
if (P != *FD->param_begin())
OS << ", ";
OS << P->getType();
}
OS << ')';
}
} else if (isa<BlockDecl>(D)) {
PresumedLoc Loc = Ctx.getSourceManager().getPresumedLoc(D->getLocation());
if (Loc.isValid()) {
OS << "block (line: " << Loc.getLine() << ", col: " << Loc.getColumn()
<< ')';
}
} else if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)) {
// FIXME: copy-pasted from CGDebugInfo.cpp.
OS << (OMD->isInstanceMethod() ? '-' : '+') << '[';
const DeclContext *DC = OMD->getDeclContext();
if (const auto *OID = dyn_cast<ObjCImplementationDecl>(DC)) {
OS << OID->getName();
} else if (const auto *OID = dyn_cast<ObjCInterfaceDecl>(DC)) {
OS << OID->getName();
} else if (const auto *OC = dyn_cast<ObjCCategoryDecl>(DC)) {
if (OC->IsClassExtension()) {
OS << OC->getClassInterface()->getName();
} else {
OS << OC->getIdentifier()->getNameStart() << '('
<< OC->getIdentifier()->getNameStart() << ')';
}
} else if (const auto *OCD = dyn_cast<ObjCCategoryImplDecl>(DC)) {
OS << OCD->getClassInterface()->getName() << '(' << OCD->getName() << ')';
}
OS << ' ' << OMD->getSelector().getAsString() << ']';
}
return Str;
}
LocationContextManager &AnalysisDeclContext::getLocationContextManager() {
assert(
ADCMgr &&
"Cannot create LocationContexts without an AnalysisDeclContextManager!");
return ADCMgr->getLocationContextManager();
}
//===----------------------------------------------------------------------===//
// FoldingSet profiling.
//===----------------------------------------------------------------------===//
void LocationContext::ProfileCommon(llvm::FoldingSetNodeID &ID,
ContextKind ck,
AnalysisDeclContext *ctx,
const LocationContext *parent,
const void *data) {
ID.AddInteger(ck);
ID.AddPointer(ctx);
ID.AddPointer(parent);
ID.AddPointer(data);
}
void StackFrameContext::Profile(llvm::FoldingSetNodeID &ID) {
Profile(ID, getAnalysisDeclContext(), getParent(), CallSite, Block,
BlockCount, Index);
}
void BlockInvocationContext::Profile(llvm::FoldingSetNodeID &ID) {
Profile(ID, getAnalysisDeclContext(), getParent(), BD, Data);
}
//===----------------------------------------------------------------------===//
// LocationContext creation.
//===----------------------------------------------------------------------===//
const StackFrameContext *LocationContextManager::getStackFrame(
AnalysisDeclContext *ctx, const LocationContext *parent, const Stmt *s,
const CFGBlock *blk, unsigned blockCount, unsigned idx) {
llvm::FoldingSetNodeID ID;
StackFrameContext::Profile(ID, ctx, parent, s, blk, blockCount, idx);
void *InsertPos;
auto *L =
cast_or_null<StackFrameContext>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
if (!L) {
L = new StackFrameContext(ctx, parent, s, blk, blockCount, idx, ++NewID);
Contexts.InsertNode(L, InsertPos);
}
return L;
}
const BlockInvocationContext *LocationContextManager::getBlockInvocationContext(
AnalysisDeclContext *ADC, const LocationContext *ParentLC,
const BlockDecl *BD, const void *Data) {
llvm::FoldingSetNodeID ID;
BlockInvocationContext::Profile(ID, ADC, ParentLC, BD, Data);
void *InsertPos;
auto *L =
cast_or_null<BlockInvocationContext>(Contexts.FindNodeOrInsertPos(ID,
InsertPos));
if (!L) {
L = new BlockInvocationContext(ADC, ParentLC, BD, Data, ++NewID);
Contexts.InsertNode(L, InsertPos);
}
return L;
}
//===----------------------------------------------------------------------===//
// LocationContext methods.
//===----------------------------------------------------------------------===//
const StackFrameContext *LocationContext::getStackFrame() const {
const LocationContext *LC = this;
while (LC) {
if (const auto *SFC = dyn_cast<StackFrameContext>(LC))
return SFC;
LC = LC->getParent();
}
return nullptr;
}
bool LocationContext::inTopFrame() const {
return getStackFrame()->inTopFrame();
}
bool LocationContext::isParentOf(const LocationContext *LC) const {
do {
const LocationContext *Parent = LC->getParent();
if (Parent == this)
return true;
else
LC = Parent;
} while (LC);
return false;
}
static void printLocation(raw_ostream &Out, const SourceManager &SM,
SourceLocation Loc) {
if (Loc.isFileID() && SM.isInMainFile(Loc))
Out << SM.getExpansionLineNumber(Loc);
else
Loc.print(Out, SM);
}
void LocationContext::dumpStack(raw_ostream &Out) const {
ASTContext &Ctx = getAnalysisDeclContext()->getASTContext();
PrintingPolicy PP(Ctx.getLangOpts());
PP.TerseOutput = 1;
const SourceManager &SM =
getAnalysisDeclContext()->getASTContext().getSourceManager();
unsigned Frame = 0;
for (const LocationContext *LCtx = this; LCtx; LCtx = LCtx->getParent()) {
switch (LCtx->getKind()) {
case StackFrame:
Out << "\t#" << Frame << ' ';
++Frame;
if (const auto *D = dyn_cast<NamedDecl>(LCtx->getDecl()))
Out << "Calling " << AnalysisDeclContext::getFunctionName(D);
else
Out << "Calling anonymous code";
if (const Stmt *S = cast<StackFrameContext>(LCtx)->getCallSite()) {
Out << " at line ";
printLocation(Out, SM, S->getBeginLoc());
}
break;
case Block:
Out << "Invoking block";
if (const Decl *D = cast<BlockInvocationContext>(LCtx)->getDecl()) {
Out << " defined at line ";
printLocation(Out, SM, D->getBeginLoc());
}
break;
}
Out << '\n';
}
}
void LocationContext::printJson(raw_ostream &Out, const char *NL,
unsigned int Space, bool IsDot,
std::function<void(const LocationContext *)>
printMoreInfoPerContext) const {
ASTContext &Ctx = getAnalysisDeclContext()->getASTContext();
PrintingPolicy PP(Ctx.getLangOpts());
PP.TerseOutput = 1;
const SourceManager &SM =
getAnalysisDeclContext()->getASTContext().getSourceManager();
unsigned Frame = 0;
for (const LocationContext *LCtx = this; LCtx; LCtx = LCtx->getParent()) {
Indent(Out, Space, IsDot)
<< "{ \"lctx_id\": " << LCtx->getID() << ", \"location_context\": \"";
switch (LCtx->getKind()) {
case StackFrame:
Out << '#' << Frame << " Call\", \"calling\": \"";
++Frame;
if (const auto *D = dyn_cast<NamedDecl>(LCtx->getDecl()))
Out << D->getQualifiedNameAsString();
else
Out << "anonymous code";
Out << "\", \"location\": ";
if (const Stmt *S = cast<StackFrameContext>(LCtx)->getCallSite()) {
printSourceLocationAsJson(Out, S->getBeginLoc(), SM);
} else {
Out << "null";
}
Out << ", \"items\": ";
break;
case Block:
Out << "Invoking block\" ";
if (const Decl *D = cast<BlockInvocationContext>(LCtx)->getDecl()) {
Out << ", \"location\": ";
printSourceLocationAsJson(Out, D->getBeginLoc(), SM);
Out << ' ';
}
break;
}
printMoreInfoPerContext(LCtx);
Out << '}';
if (LCtx->getParent())
Out << ',';
Out << NL;
}
}
LLVM_DUMP_METHOD void LocationContext::dump() const { printJson(llvm::errs()); }
//===----------------------------------------------------------------------===//
// Lazily generated map to query the external variables referenced by a Block.
//===----------------------------------------------------------------------===//
namespace {
class FindBlockDeclRefExprsVals : public StmtVisitor<FindBlockDeclRefExprsVals>{
BumpVector<const VarDecl *> &BEVals;
BumpVectorContext &BC;
llvm::SmallPtrSet<const VarDecl *, 4> Visited;
llvm::SmallPtrSet<const DeclContext *, 4> IgnoredContexts;
public:
FindBlockDeclRefExprsVals(BumpVector<const VarDecl*> &bevals,
BumpVectorContext &bc)
: BEVals(bevals), BC(bc) {}
void VisitStmt(Stmt *S) {
for (auto *Child : S->children())
if (Child)
Visit(Child);
}
void VisitDeclRefExpr(DeclRefExpr *DR) {
// Non-local variables are also directly modified.
if (const auto *VD = dyn_cast<VarDecl>(DR->getDecl())) {
if (!VD->hasLocalStorage()) {
if (Visited.insert(VD).second)
BEVals.push_back(VD, BC);
}
}
}
void VisitBlockExpr(BlockExpr *BR) {
// Blocks containing blocks can transitively capture more variables.
IgnoredContexts.insert(BR->getBlockDecl());
Visit(BR->getBlockDecl()->getBody());
}
void VisitPseudoObjectExpr(PseudoObjectExpr *PE) {
for (PseudoObjectExpr::semantics_iterator it = PE->semantics_begin(),
et = PE->semantics_end(); it != et; ++it) {
Expr *Semantic = *it;
if (auto *OVE = dyn_cast<OpaqueValueExpr>(Semantic))
Semantic = OVE->getSourceExpr();
Visit(Semantic);
}
}
};
} // namespace
using DeclVec = BumpVector<const VarDecl *>;
static DeclVec* LazyInitializeReferencedDecls(const BlockDecl *BD,
void *&Vec,
llvm::BumpPtrAllocator &A) {
if (Vec)
return (DeclVec*) Vec;
BumpVectorContext BC(A);
DeclVec *BV = (DeclVec*) A.Allocate<DeclVec>();
new (BV) DeclVec(BC, 10);
// Go through the capture list.
for (const auto &CI : BD->captures()) {
BV->push_back(CI.getVariable(), BC);
}
// Find the referenced global/static variables.
FindBlockDeclRefExprsVals F(*BV, BC);
F.Visit(BD->getBody());
Vec = BV;
return BV;
}
llvm::iterator_range<AnalysisDeclContext::referenced_decls_iterator>
AnalysisDeclContext::getReferencedBlockVars(const BlockDecl *BD) {
if (!ReferencedBlockVars)
ReferencedBlockVars = new llvm::DenseMap<const BlockDecl*,void*>();
const DeclVec *V =
LazyInitializeReferencedDecls(BD, (*ReferencedBlockVars)[BD], A);
return llvm::make_range(V->begin(), V->end());
}
std::unique_ptr<ManagedAnalysis> &AnalysisDeclContext::getAnalysisImpl(const void *tag) {
if (!ManagedAnalyses)
ManagedAnalyses = new ManagedAnalysisMap();
ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
return (*M)[tag];
}
//===----------------------------------------------------------------------===//
// Cleanup.
//===----------------------------------------------------------------------===//
ManagedAnalysis::~ManagedAnalysis() = default;
AnalysisDeclContext::~AnalysisDeclContext() {
delete forcedBlkExprs;
delete ReferencedBlockVars;
delete (ManagedAnalysisMap*) ManagedAnalyses;
}
LocationContext::~LocationContext() = default;
LocationContextManager::~LocationContextManager() {
clear();
}
void LocationContextManager::clear() {
for (llvm::FoldingSet<LocationContext>::iterator I = Contexts.begin(),
E = Contexts.end(); I != E; ) {
LocationContext *LC = &*I;
++I;
delete LC;
}
Contexts.clear();
}