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//== AnalysisDeclContext.cpp - Analysis context for Path Sens analysis -*- C++ -*-//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines AnalysisDeclContext, a class that manages the analysis context
// data for path sensitive analysis.
//
//===----------------------------------------------------------------------===//
#include "clang/Analysis/AnalysisContext.h"
#include "BodyFarm.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/ParentMap.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
#include "clang/Analysis/Analyses/LiveVariables.h"
#include "clang/Analysis/Analyses/PseudoConstantAnalysis.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/CFGStmtMap.h"
#include "clang/Analysis/Support/BumpVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
typedef llvm::DenseMap<const void *, ManagedAnalysis *> ManagedAnalysisMap;
AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
const Decl *d,
const CFG::BuildOptions &buildOptions)
: Manager(Mgr),
D(d),
cfgBuildOptions(buildOptions),
forcedBlkExprs(nullptr),
builtCFG(false),
builtCompleteCFG(false),
ReferencedBlockVars(nullptr),
ManagedAnalyses(nullptr)
{
cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
}
AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
const Decl *d)
: Manager(Mgr),
D(d),
forcedBlkExprs(nullptr),
builtCFG(false),
builtCompleteCFG(false),
ReferencedBlockVars(nullptr),
ManagedAnalyses(nullptr)
{
cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
}
AnalysisDeclContextManager::AnalysisDeclContextManager(bool useUnoptimizedCFG,
bool addImplicitDtors,
bool addInitializers,
bool addTemporaryDtors,
bool synthesizeBodies,
bool addStaticInitBranch,
bool addCXXNewAllocator,
CodeInjector *injector)
: Injector(injector), SynthesizeBodies(synthesizeBodies)
{
cfgBuildOptions.PruneTriviallyFalseEdges = !useUnoptimizedCFG;
cfgBuildOptions.AddImplicitDtors = addImplicitDtors;
cfgBuildOptions.AddInitializers = addInitializers;
cfgBuildOptions.AddTemporaryDtors = addTemporaryDtors;
cfgBuildOptions.AddStaticInitBranches = addStaticInitBranch;
cfgBuildOptions.AddCXXNewAllocator = addCXXNewAllocator;
}
void AnalysisDeclContextManager::clear() {
llvm::DeleteContainerSeconds(Contexts);
}
static BodyFarm &getBodyFarm(ASTContext &C, CodeInjector *injector = nullptr) {
static BodyFarm *BF = new BodyFarm(C, injector);
return *BF;
}
Stmt *AnalysisDeclContext::getBody(bool &IsAutosynthesized) const {
IsAutosynthesized = false;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
Stmt *Body = FD->getBody();
if (Manager && Manager->synthesizeBodies()) {
Stmt *SynthesizedBody =
getBodyFarm(getASTContext(), Manager->Injector.get()).getBody(FD);
if (SynthesizedBody) {
Body = SynthesizedBody;
IsAutosynthesized = true;
}
}
return Body;
}
else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
Stmt *Body = MD->getBody();
if (Manager && Manager->synthesizeBodies()) {
Stmt *SynthesizedBody =
getBodyFarm(getASTContext(), Manager->Injector.get()).getBody(MD);
if (SynthesizedBody) {
Body = SynthesizedBody;
IsAutosynthesized = true;
}
}
return Body;
} else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D))
return BD->getBody();
else if (const FunctionTemplateDecl *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->getLocStart().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 ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
return MD->getSelfDecl();
if (const BlockDecl *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 LambdaCapture &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 Expr *e = dyn_cast<Expr>(stmt))
stmt = e->IgnoreParens();
(void) (*forcedBlkExprs)[stmt];
}
const CFGBlock *
AnalysisDeclContext::getBlockForRegisteredExpression(const Stmt *stmt) {
assert(forcedBlkExprs);
if (const Expr *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 CXXConstructorDecl *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;
}
PseudoConstantAnalysis *AnalysisDeclContext::getPseudoConstantAnalysis() {
if (!PCA)
PCA.reset(new PseudoConstantAnalysis(getBody()));
return PCA.get();
}
AnalysisDeclContext *AnalysisDeclContextManager::getContext(const Decl *D) {
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
// Calling 'hasBody' replaces 'FD' in place with the FunctionDecl
// that has the body.
FD->hasBody(FD);
D = FD;
}
AnalysisDeclContext *&AC = Contexts[D];
if (!AC)
AC = new AnalysisDeclContext(this, D, cfgBuildOptions);
return AC;
}
const StackFrameContext *
AnalysisDeclContext::getStackFrame(LocationContext const *Parent, const Stmt *S,
const CFGBlock *Blk, unsigned Idx) {
return getLocationContextManager().getStackFrame(this, Parent, S, Blk, Idx);
}
const BlockInvocationContext *
AnalysisDeclContext::getBlockInvocationContext(const LocationContext *parent,
const clang::BlockDecl *BD,
const void *ContextData) {
return getLocationContextManager().getBlockInvocationContext(this, parent,
BD, ContextData);
}
bool AnalysisDeclContext::isInStdNamespace(const Decl *D) {
const DeclContext *DC = D->getDeclContext()->getEnclosingNamespaceContext();
const NamespaceDecl *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();
}
LocationContextManager & AnalysisDeclContext::getLocationContextManager() {
assert(Manager &&
"Cannot create LocationContexts without an AnalysisDeclContextManager!");
return Manager->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, Index);
}
void ScopeContext::Profile(llvm::FoldingSetNodeID &ID) {
Profile(ID, getAnalysisDeclContext(), getParent(), Enter);
}
void BlockInvocationContext::Profile(llvm::FoldingSetNodeID &ID) {
Profile(ID, getAnalysisDeclContext(), getParent(), BD, ContextData);
}
//===----------------------------------------------------------------------===//
// LocationContext creation.
//===----------------------------------------------------------------------===//
template <typename LOC, typename DATA>
const LOC*
LocationContextManager::getLocationContext(AnalysisDeclContext *ctx,
const LocationContext *parent,
const DATA *d) {
llvm::FoldingSetNodeID ID;
LOC::Profile(ID, ctx, parent, d);
void *InsertPos;
LOC *L = cast_or_null<LOC>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
if (!L) {
L = new LOC(ctx, parent, d);
Contexts.InsertNode(L, InsertPos);
}
return L;
}
const StackFrameContext*
LocationContextManager::getStackFrame(AnalysisDeclContext *ctx,
const LocationContext *parent,
const Stmt *s,
const CFGBlock *blk, unsigned idx) {
llvm::FoldingSetNodeID ID;
StackFrameContext::Profile(ID, ctx, parent, s, blk, idx);
void *InsertPos;
StackFrameContext *L =
cast_or_null<StackFrameContext>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
if (!L) {
L = new StackFrameContext(ctx, parent, s, blk, idx);
Contexts.InsertNode(L, InsertPos);
}
return L;
}
const ScopeContext *
LocationContextManager::getScope(AnalysisDeclContext *ctx,
const LocationContext *parent,
const Stmt *s) {
return getLocationContext<ScopeContext, Stmt>(ctx, parent, s);
}
const BlockInvocationContext *
LocationContextManager::getBlockInvocationContext(AnalysisDeclContext *ctx,
const LocationContext *parent,
const BlockDecl *BD,
const void *ContextData) {
llvm::FoldingSetNodeID ID;
BlockInvocationContext::Profile(ID, ctx, parent, BD, ContextData);
void *InsertPos;
BlockInvocationContext *L =
cast_or_null<BlockInvocationContext>(Contexts.FindNodeOrInsertPos(ID,
InsertPos));
if (!L) {
L = new BlockInvocationContext(ctx, parent, BD, ContextData);
Contexts.InsertNode(L, InsertPos);
}
return L;
}
//===----------------------------------------------------------------------===//
// LocationContext methods.
//===----------------------------------------------------------------------===//
const StackFrameContext *LocationContext::getCurrentStackFrame() const {
const LocationContext *LC = this;
while (LC) {
if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC))
return SFC;
LC = LC->getParent();
}
return nullptr;
}
bool LocationContext::inTopFrame() const {
return getCurrentStackFrame()->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;
}
void LocationContext::dumpStack(raw_ostream &OS, StringRef Indent) const {
ASTContext &Ctx = getAnalysisDeclContext()->getASTContext();
PrintingPolicy PP(Ctx.getLangOpts());
PP.TerseOutput = 1;
unsigned Frame = 0;
for (const LocationContext *LCtx = this; LCtx; LCtx = LCtx->getParent()) {
switch (LCtx->getKind()) {
case StackFrame:
OS << Indent << '#' << Frame++ << ' ';
cast<StackFrameContext>(LCtx)->getDecl()->print(OS, PP);
OS << '\n';
break;
case Scope:
OS << Indent << " (scope)\n";
break;
case Block:
OS << Indent << " (block context: "
<< cast<BlockInvocationContext>(LCtx)->getContextData()
<< ")\n";
break;
}
}
}
LLVM_DUMP_METHOD void LocationContext::dumpStack() const {
dumpStack(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 (Stmt *Child : S->children())
if (Child)
Visit(Child);
}
void VisitDeclRefExpr(DeclRefExpr *DR) {
// Non-local variables are also directly modified.
if (const VarDecl *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 (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Semantic))
Semantic = OVE->getSourceExpr();
Visit(Semantic);
}
}
};
} // end anonymous namespace
typedef BumpVector<const VarDecl*> DeclVec;
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());
}
ManagedAnalysis *&AnalysisDeclContext::getAnalysisImpl(const void *tag) {
if (!ManagedAnalyses)
ManagedAnalyses = new ManagedAnalysisMap();
ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
return (*M)[tag];
}
//===----------------------------------------------------------------------===//
// Cleanup.
//===----------------------------------------------------------------------===//
ManagedAnalysis::~ManagedAnalysis() {}
AnalysisDeclContext::~AnalysisDeclContext() {
delete forcedBlkExprs;
delete ReferencedBlockVars;
// Release the managed analyses.
if (ManagedAnalyses) {
ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
llvm::DeleteContainerSeconds(*M);
delete M;
}
}
AnalysisDeclContextManager::~AnalysisDeclContextManager() {
llvm::DeleteContainerSeconds(Contexts);
}
LocationContext::~LocationContext() {}
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();
}