//== AnalysisContext.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 AnalysisContext, a class that manages the analysis context
// data for path sensitive analysis.
//
//===----------------------------------------------------------------------===//
#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/LiveVariables.h"
#include "clang/Analysis/Analyses/PseudoConstantAnalysis.h"
#include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
#include "clang/Analysis/AnalysisContext.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/CFGStmtMap.h"
#include "clang/Analysis/Support/BumpVector.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/Support/ErrorHandling.h"
using namespace clang;
AnalysisContext::AnalysisContext(const Decl *d,
idx::TranslationUnit *tu,
bool useUnoptimizedCFG,
bool addehedges,
bool addImplicitDtors,
bool addInitializers)
: D(d), TU(tu),
forcedBlkExprs(0),
builtCFG(false), builtCompleteCFG(false),
useUnoptimizedCFG(useUnoptimizedCFG),
ReferencedBlockVars(0)
{
cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
cfgBuildOptions.AddEHEdges = addehedges;
cfgBuildOptions.AddImplicitDtors = addImplicitDtors;
cfgBuildOptions.AddInitializers = addInitializers;
}
void AnalysisContextManager::clear() {
for (ContextMap::iterator I = Contexts.begin(), E = Contexts.end(); I!=E; ++I)
delete I->second;
Contexts.clear();
}
Stmt *AnalysisContext::getBody() {
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
return FD->getBody();
else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
return MD->getBody();
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");
}
const ImplicitParamDecl *AnalysisContext::getSelfDecl() const {
if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
return MD->getSelfDecl();
return NULL;
}
void AnalysisContext::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 *
AnalysisContext::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;
}
CFG *AnalysisContext::getCFG() {
if (useUnoptimizedCFG)
return getUnoptimizedCFG();
if (!builtCFG) {
cfg.reset(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;
}
return cfg.get();
}
CFG *AnalysisContext::getUnoptimizedCFG() {
if (!builtCompleteCFG) {
CFG::BuildOptions B = cfgBuildOptions;
B.PruneTriviallyFalseEdges = false;
completeCFG.reset(CFG::buildCFG(D, getBody(), &D->getASTContext(), B));
// Even when the cfg is not successfully built, we don't
// want to try building it again.
builtCompleteCFG = true;
}
return completeCFG.get();
}
CFGStmtMap *AnalysisContext::getCFGStmtMap() {
if (cfgStmtMap)
return cfgStmtMap.get();
if (CFG *c = getCFG()) {
cfgStmtMap.reset(CFGStmtMap::Build(c, &getParentMap()));
return cfgStmtMap.get();
}
return 0;
}
CFGReverseBlockReachabilityAnalysis *AnalysisContext::getCFGReachablityAnalysis() {
if (CFA)
return CFA.get();
if (CFG *c = getCFG()) {
CFA.reset(new CFGReverseBlockReachabilityAnalysis(*c));
return CFA.get();
}
return 0;
}
void AnalysisContext::dumpCFG() {
getCFG()->dump(getASTContext().getLangOptions());
}
ParentMap &AnalysisContext::getParentMap() {
if (!PM)
PM.reset(new ParentMap(getBody()));
return *PM;
}
PseudoConstantAnalysis *AnalysisContext::getPseudoConstantAnalysis() {
if (!PCA)
PCA.reset(new PseudoConstantAnalysis(getBody()));
return PCA.get();
}
LiveVariables *AnalysisContext::getLiveVariables() {
if (!liveness) {
if (CFG *c = getCFG()) {
liveness.reset(new LiveVariables(*this));
liveness->runOnCFG(*c);
liveness->runOnAllBlocks(*c, 0, true);
}
}
return liveness.get();
}
LiveVariables *AnalysisContext::getRelaxedLiveVariables() {
if (!relaxedLiveness)
if (CFG *c = getCFG()) {
relaxedLiveness.reset(new LiveVariables(*this, false));
relaxedLiveness->runOnCFG(*c);
relaxedLiveness->runOnAllBlocks(*c, 0, true);
}
return relaxedLiveness.get();
}
AnalysisContext *AnalysisContextManager::getContext(const Decl *D,
idx::TranslationUnit *TU) {
AnalysisContext *&AC = Contexts[D];
if (!AC)
AC = new AnalysisContext(D, TU, UseUnoptimizedCFG, false,
AddImplicitDtors, AddInitializers);
return AC;
}
//===----------------------------------------------------------------------===//
// FoldingSet profiling.
//===----------------------------------------------------------------------===//
void LocationContext::ProfileCommon(llvm::FoldingSetNodeID &ID,
ContextKind ck,
AnalysisContext *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, getAnalysisContext(), getParent(), CallSite, Block, Index);
}
void ScopeContext::Profile(llvm::FoldingSetNodeID &ID) {
Profile(ID, getAnalysisContext(), getParent(), Enter);
}
void BlockInvocationContext::Profile(llvm::FoldingSetNodeID &ID) {
Profile(ID, getAnalysisContext(), getParent(), BD);
}
//===----------------------------------------------------------------------===//
// LocationContext creation.
//===----------------------------------------------------------------------===//
template <typename LOC, typename DATA>
const LOC*
LocationContextManager::getLocationContext(AnalysisContext *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(AnalysisContext *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(AnalysisContext *ctx,
const LocationContext *parent,
const Stmt *s) {
return getLocationContext<ScopeContext, Stmt>(ctx, parent, s);
}
//===----------------------------------------------------------------------===//
// 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 NULL;
}
const StackFrameContext *
LocationContext::getStackFrameForDeclContext(const DeclContext *DC) const {
const LocationContext *LC = this;
while (LC) {
if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC)) {
if (cast<DeclContext>(SFC->getDecl()) == DC)
return SFC;
}
LC = LC->getParent();
}
return NULL;
}
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;
}
//===----------------------------------------------------------------------===//
// 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::DenseMap<const VarDecl*, unsigned> Visited;
llvm::SmallSet<const DeclContext*, 4> IgnoredContexts;
public:
FindBlockDeclRefExprsVals(BumpVector<const VarDecl*> &bevals,
BumpVectorContext &bc)
: BEVals(bevals), BC(bc) {}
bool IsTrackedDecl(const VarDecl *VD) {
const DeclContext *DC = VD->getDeclContext();
return IgnoredContexts.count(DC) == 0;
}
void VisitStmt(Stmt *S) {
for (Stmt::child_range I = S->children(); I; ++I)
if (Stmt *child = *I)
Visit(child);
}
void VisitDeclRefExpr(const DeclRefExpr *DR) {
// Non-local variables are also directly modified.
if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()))
if (!VD->hasLocalStorage()) {
unsigned &flag = Visited[VD];
if (!flag) {
flag = 1;
BEVals.push_back(VD, BC);
}
}
}
void VisitBlockDeclRefExpr(BlockDeclRefExpr *DR) {
if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
unsigned &flag = Visited[VD];
if (!flag) {
flag = 1;
if (IsTrackedDecl(VD))
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());
}
};
} // 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);
// Find the referenced variables.
FindBlockDeclRefExprsVals F(*BV, BC);
F.Visit(BD->getBody());
Vec = BV;
return BV;
}
std::pair<AnalysisContext::referenced_decls_iterator,
AnalysisContext::referenced_decls_iterator>
AnalysisContext::getReferencedBlockVars(const BlockDecl *BD) {
if (!ReferencedBlockVars)
ReferencedBlockVars = new llvm::DenseMap<const BlockDecl*,void*>();
DeclVec *V = LazyInitializeReferencedDecls(BD, (*ReferencedBlockVars)[BD], A);
return std::make_pair(V->begin(), V->end());
}
//===----------------------------------------------------------------------===//
// Cleanup.
//===----------------------------------------------------------------------===//
AnalysisContext::~AnalysisContext() {
delete forcedBlkExprs;
delete ReferencedBlockVars;
}
AnalysisContextManager::~AnalysisContextManager() {
for (ContextMap::iterator I = Contexts.begin(), E = Contexts.end(); I!=E; ++I)
delete I->second;
}
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();
}
