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-rw-r--r--contrib/llvm/tools/clang/lib/Analysis/UninitializedValues.cpp724
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diff --git a/contrib/llvm/tools/clang/lib/Analysis/UninitializedValues.cpp b/contrib/llvm/tools/clang/lib/Analysis/UninitializedValues.cpp
new file mode 100644
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--- /dev/null
+++ b/contrib/llvm/tools/clang/lib/Analysis/UninitializedValues.cpp
@@ -0,0 +1,724 @@
+//==- UninitializedValues.cpp - Find Uninitialized Values -------*- C++ --*-==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements uninitialized values analysis for source-level CFGs.
+//
+//===----------------------------------------------------------------------===//
+
+#include <utility>
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/PackedVector.h"
+#include "llvm/ADT/DenseMap.h"
+#include "clang/AST/Decl.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Analysis/Visitors/CFGRecStmtDeclVisitor.h"
+#include "clang/Analysis/Analyses/UninitializedValues.h"
+#include "llvm/Support/SaveAndRestore.h"
+
+using namespace clang;
+
+static bool isTrackedVar(const VarDecl *vd, const DeclContext *dc) {
+ if (vd->isLocalVarDecl() && !vd->hasGlobalStorage() &&
+ !vd->isExceptionVariable() &&
+ vd->getDeclContext() == dc) {
+ QualType ty = vd->getType();
+ return ty->isScalarType() || ty->isVectorType();
+ }
+ return false;
+}
+
+//------------------------------------------------------------------------====//
+// DeclToIndex: a mapping from Decls we track to value indices.
+//====------------------------------------------------------------------------//
+
+namespace {
+class DeclToIndex {
+ llvm::DenseMap<const VarDecl *, unsigned> map;
+public:
+ DeclToIndex() {}
+
+ /// Compute the actual mapping from declarations to bits.
+ void computeMap(const DeclContext &dc);
+
+ /// Return the number of declarations in the map.
+ unsigned size() const { return map.size(); }
+
+ /// Returns the bit vector index for a given declaration.
+ llvm::Optional<unsigned> getValueIndex(const VarDecl *d) const;
+};
+}
+
+void DeclToIndex::computeMap(const DeclContext &dc) {
+ unsigned count = 0;
+ DeclContext::specific_decl_iterator<VarDecl> I(dc.decls_begin()),
+ E(dc.decls_end());
+ for ( ; I != E; ++I) {
+ const VarDecl *vd = *I;
+ if (isTrackedVar(vd, &dc))
+ map[vd] = count++;
+ }
+}
+
+llvm::Optional<unsigned> DeclToIndex::getValueIndex(const VarDecl *d) const {
+ llvm::DenseMap<const VarDecl *, unsigned>::const_iterator I = map.find(d);
+ if (I == map.end())
+ return llvm::Optional<unsigned>();
+ return I->second;
+}
+
+//------------------------------------------------------------------------====//
+// CFGBlockValues: dataflow values for CFG blocks.
+//====------------------------------------------------------------------------//
+
+// These values are defined in such a way that a merge can be done using
+// a bitwise OR.
+enum Value { Unknown = 0x0, /* 00 */
+ Initialized = 0x1, /* 01 */
+ Uninitialized = 0x2, /* 10 */
+ MayUninitialized = 0x3 /* 11 */ };
+
+static bool isUninitialized(const Value v) {
+ return v >= Uninitialized;
+}
+static bool isAlwaysUninit(const Value v) {
+ return v == Uninitialized;
+}
+
+namespace {
+
+typedef llvm::PackedVector<Value, 2> ValueVector;
+typedef std::pair<ValueVector *, ValueVector *> BVPair;
+
+class CFGBlockValues {
+ const CFG &cfg;
+ BVPair *vals;
+ ValueVector scratch;
+ DeclToIndex declToIndex;
+
+ ValueVector &lazyCreate(ValueVector *&bv);
+public:
+ CFGBlockValues(const CFG &cfg);
+ ~CFGBlockValues();
+
+ unsigned getNumEntries() const { return declToIndex.size(); }
+
+ void computeSetOfDeclarations(const DeclContext &dc);
+ ValueVector &getValueVector(const CFGBlock *block,
+ const CFGBlock *dstBlock);
+
+ BVPair &getValueVectors(const CFGBlock *block, bool shouldLazyCreate);
+
+ void mergeIntoScratch(ValueVector const &source, bool isFirst);
+ bool updateValueVectorWithScratch(const CFGBlock *block);
+ bool updateValueVectors(const CFGBlock *block, const BVPair &newVals);
+
+ bool hasNoDeclarations() const {
+ return declToIndex.size() == 0;
+ }
+
+ void resetScratch();
+ ValueVector &getScratch() { return scratch; }
+
+ ValueVector::reference operator[](const VarDecl *vd);
+};
+} // end anonymous namespace
+
+CFGBlockValues::CFGBlockValues(const CFG &c) : cfg(c), vals(0) {
+ unsigned n = cfg.getNumBlockIDs();
+ if (!n)
+ return;
+ vals = new std::pair<ValueVector*, ValueVector*>[n];
+ memset((void*)vals, 0, sizeof(*vals) * n);
+}
+
+CFGBlockValues::~CFGBlockValues() {
+ unsigned n = cfg.getNumBlockIDs();
+ if (n == 0)
+ return;
+ for (unsigned i = 0; i < n; ++i) {
+ delete vals[i].first;
+ delete vals[i].second;
+ }
+ delete [] vals;
+}
+
+void CFGBlockValues::computeSetOfDeclarations(const DeclContext &dc) {
+ declToIndex.computeMap(dc);
+ scratch.resize(declToIndex.size());
+}
+
+ValueVector &CFGBlockValues::lazyCreate(ValueVector *&bv) {
+ if (!bv)
+ bv = new ValueVector(declToIndex.size());
+ return *bv;
+}
+
+/// This function pattern matches for a '&&' or '||' that appears at
+/// the beginning of a CFGBlock that also (1) has a terminator and
+/// (2) has no other elements. If such an expression is found, it is returned.
+static const BinaryOperator *getLogicalOperatorInChain(const CFGBlock *block) {
+ if (block->empty())
+ return 0;
+
+ const CFGStmt *cstmt = block->front().getAs<CFGStmt>();
+ if (!cstmt)
+ return 0;
+
+ const BinaryOperator *b = dyn_cast_or_null<BinaryOperator>(cstmt->getStmt());
+
+ if (!b || !b->isLogicalOp())
+ return 0;
+
+ if (block->pred_size() == 2) {
+ if (block->getTerminatorCondition() == b) {
+ if (block->succ_size() == 2)
+ return b;
+ }
+ else if (block->size() == 1)
+ return b;
+ }
+
+ return 0;
+}
+
+ValueVector &CFGBlockValues::getValueVector(const CFGBlock *block,
+ const CFGBlock *dstBlock) {
+ unsigned idx = block->getBlockID();
+ if (dstBlock && getLogicalOperatorInChain(block)) {
+ if (*block->succ_begin() == dstBlock)
+ return lazyCreate(vals[idx].first);
+ assert(*(block->succ_begin()+1) == dstBlock);
+ return lazyCreate(vals[idx].second);
+ }
+
+ assert(vals[idx].second == 0);
+ return lazyCreate(vals[idx].first);
+}
+
+BVPair &CFGBlockValues::getValueVectors(const clang::CFGBlock *block,
+ bool shouldLazyCreate) {
+ unsigned idx = block->getBlockID();
+ lazyCreate(vals[idx].first);
+ if (shouldLazyCreate)
+ lazyCreate(vals[idx].second);
+ return vals[idx];
+}
+
+#if 0
+static void printVector(const CFGBlock *block, ValueVector &bv,
+ unsigned num) {
+
+ llvm::errs() << block->getBlockID() << " :";
+ for (unsigned i = 0; i < bv.size(); ++i) {
+ llvm::errs() << ' ' << bv[i];
+ }
+ llvm::errs() << " : " << num << '\n';
+}
+
+static void printVector(const char *name, ValueVector const &bv) {
+ llvm::errs() << name << " : ";
+ for (unsigned i = 0; i < bv.size(); ++i) {
+ llvm::errs() << ' ' << bv[i];
+ }
+ llvm::errs() << "\n";
+}
+#endif
+
+void CFGBlockValues::mergeIntoScratch(ValueVector const &source,
+ bool isFirst) {
+ if (isFirst)
+ scratch = source;
+ else
+ scratch |= source;
+}
+
+bool CFGBlockValues::updateValueVectorWithScratch(const CFGBlock *block) {
+ ValueVector &dst = getValueVector(block, 0);
+ bool changed = (dst != scratch);
+ if (changed)
+ dst = scratch;
+#if 0
+ printVector(block, scratch, 0);
+#endif
+ return changed;
+}
+
+bool CFGBlockValues::updateValueVectors(const CFGBlock *block,
+ const BVPair &newVals) {
+ BVPair &vals = getValueVectors(block, true);
+ bool changed = *newVals.first != *vals.first ||
+ *newVals.second != *vals.second;
+ *vals.first = *newVals.first;
+ *vals.second = *newVals.second;
+#if 0
+ printVector(block, *vals.first, 1);
+ printVector(block, *vals.second, 2);
+#endif
+ return changed;
+}
+
+void CFGBlockValues::resetScratch() {
+ scratch.reset();
+}
+
+ValueVector::reference CFGBlockValues::operator[](const VarDecl *vd) {
+ const llvm::Optional<unsigned> &idx = declToIndex.getValueIndex(vd);
+ assert(idx.hasValue());
+ return scratch[idx.getValue()];
+}
+
+//------------------------------------------------------------------------====//
+// Worklist: worklist for dataflow analysis.
+//====------------------------------------------------------------------------//
+
+namespace {
+class DataflowWorklist {
+ SmallVector<const CFGBlock *, 20> worklist;
+ llvm::BitVector enqueuedBlocks;
+public:
+ DataflowWorklist(const CFG &cfg) : enqueuedBlocks(cfg.getNumBlockIDs()) {}
+
+ void enqueueSuccessors(const CFGBlock *block);
+ const CFGBlock *dequeue();
+};
+}
+
+void DataflowWorklist::enqueueSuccessors(const clang::CFGBlock *block) {
+ unsigned OldWorklistSize = worklist.size();
+ for (CFGBlock::const_succ_iterator I = block->succ_begin(),
+ E = block->succ_end(); I != E; ++I) {
+ const CFGBlock *Successor = *I;
+ if (!Successor || enqueuedBlocks[Successor->getBlockID()])
+ continue;
+ worklist.push_back(Successor);
+ enqueuedBlocks[Successor->getBlockID()] = true;
+ }
+ if (OldWorklistSize == 0 || OldWorklistSize == worklist.size())
+ return;
+
+ // Rotate the newly added blocks to the start of the worklist so that it forms
+ // a proper queue when we pop off the end of the worklist.
+ std::rotate(worklist.begin(), worklist.begin() + OldWorklistSize,
+ worklist.end());
+}
+
+const CFGBlock *DataflowWorklist::dequeue() {
+ if (worklist.empty())
+ return 0;
+ const CFGBlock *b = worklist.back();
+ worklist.pop_back();
+ enqueuedBlocks[b->getBlockID()] = false;
+ return b;
+}
+
+//------------------------------------------------------------------------====//
+// Transfer function for uninitialized values analysis.
+//====------------------------------------------------------------------------//
+
+namespace {
+class FindVarResult {
+ const VarDecl *vd;
+ const DeclRefExpr *dr;
+public:
+ FindVarResult(VarDecl *vd, DeclRefExpr *dr) : vd(vd), dr(dr) {}
+
+ const DeclRefExpr *getDeclRefExpr() const { return dr; }
+ const VarDecl *getDecl() const { return vd; }
+};
+
+class TransferFunctions : public StmtVisitor<TransferFunctions> {
+ CFGBlockValues &vals;
+ const CFG &cfg;
+ AnalysisDeclContext &ac;
+ UninitVariablesHandler *handler;
+
+ /// The last DeclRefExpr seen when analyzing a block. Used to
+ /// cheat when detecting cases when the address of a variable is taken.
+ DeclRefExpr *lastDR;
+
+ /// The last lvalue-to-rvalue conversion of a variable whose value
+ /// was uninitialized. Normally this results in a warning, but it is
+ /// possible to either silence the warning in some cases, or we
+ /// propagate the uninitialized value.
+ CastExpr *lastLoad;
+
+ /// For some expressions, we want to ignore any post-processing after
+ /// visitation.
+ bool skipProcessUses;
+
+public:
+ TransferFunctions(CFGBlockValues &vals, const CFG &cfg,
+ AnalysisDeclContext &ac,
+ UninitVariablesHandler *handler)
+ : vals(vals), cfg(cfg), ac(ac), handler(handler),
+ lastDR(0), lastLoad(0),
+ skipProcessUses(false) {}
+
+ void reportUninit(const DeclRefExpr *ex, const VarDecl *vd,
+ bool isAlwaysUninit);
+
+ void VisitBlockExpr(BlockExpr *be);
+ void VisitDeclStmt(DeclStmt *ds);
+ void VisitDeclRefExpr(DeclRefExpr *dr);
+ void VisitUnaryOperator(UnaryOperator *uo);
+ void VisitBinaryOperator(BinaryOperator *bo);
+ void VisitCastExpr(CastExpr *ce);
+ void VisitObjCForCollectionStmt(ObjCForCollectionStmt *fs);
+ void Visit(Stmt *s);
+
+ bool isTrackedVar(const VarDecl *vd) {
+ return ::isTrackedVar(vd, cast<DeclContext>(ac.getDecl()));
+ }
+
+ FindVarResult findBlockVarDecl(Expr *ex);
+
+ void ProcessUses(Stmt *s = 0);
+};
+}
+
+static const Expr *stripCasts(ASTContext &C, const Expr *Ex) {
+ while (Ex) {
+ Ex = Ex->IgnoreParenNoopCasts(C);
+ if (const CastExpr *CE = dyn_cast<CastExpr>(Ex)) {
+ if (CE->getCastKind() == CK_LValueBitCast) {
+ Ex = CE->getSubExpr();
+ continue;
+ }
+ }
+ break;
+ }
+ return Ex;
+}
+
+void TransferFunctions::reportUninit(const DeclRefExpr *ex,
+ const VarDecl *vd, bool isAlwaysUnit) {
+ if (handler) handler->handleUseOfUninitVariable(ex, vd, isAlwaysUnit);
+}
+
+FindVarResult TransferFunctions::findBlockVarDecl(Expr *ex) {
+ if (DeclRefExpr *dr = dyn_cast<DeclRefExpr>(ex->IgnoreParenCasts()))
+ if (VarDecl *vd = dyn_cast<VarDecl>(dr->getDecl()))
+ if (isTrackedVar(vd))
+ return FindVarResult(vd, dr);
+ return FindVarResult(0, 0);
+}
+
+void TransferFunctions::VisitObjCForCollectionStmt(ObjCForCollectionStmt *fs) {
+ // This represents an initialization of the 'element' value.
+ Stmt *element = fs->getElement();
+ const VarDecl *vd = 0;
+
+ if (DeclStmt *ds = dyn_cast<DeclStmt>(element)) {
+ vd = cast<VarDecl>(ds->getSingleDecl());
+ if (!isTrackedVar(vd))
+ vd = 0;
+ } else {
+ // Initialize the value of the reference variable.
+ const FindVarResult &res = findBlockVarDecl(cast<Expr>(element));
+ vd = res.getDecl();
+ }
+
+ if (vd)
+ vals[vd] = Initialized;
+}
+
+void TransferFunctions::VisitBlockExpr(BlockExpr *be) {
+ const BlockDecl *bd = be->getBlockDecl();
+ for (BlockDecl::capture_const_iterator i = bd->capture_begin(),
+ e = bd->capture_end() ; i != e; ++i) {
+ const VarDecl *vd = i->getVariable();
+ if (!isTrackedVar(vd))
+ continue;
+ if (i->isByRef()) {
+ vals[vd] = Initialized;
+ continue;
+ }
+ Value v = vals[vd];
+ if (handler && isUninitialized(v))
+ handler->handleUseOfUninitVariable(be, vd, isAlwaysUninit(v));
+ }
+}
+
+void TransferFunctions::VisitDeclRefExpr(DeclRefExpr *dr) {
+ // Record the last DeclRefExpr seen. This is an lvalue computation.
+ // We use this value to later detect if a variable "escapes" the analysis.
+ if (const VarDecl *vd = dyn_cast<VarDecl>(dr->getDecl()))
+ if (isTrackedVar(vd)) {
+ ProcessUses();
+ lastDR = dr;
+ }
+}
+
+void TransferFunctions::VisitDeclStmt(DeclStmt *ds) {
+ for (DeclStmt::decl_iterator DI = ds->decl_begin(), DE = ds->decl_end();
+ DI != DE; ++DI) {
+ if (VarDecl *vd = dyn_cast<VarDecl>(*DI)) {
+ if (isTrackedVar(vd)) {
+ if (Expr *init = vd->getInit()) {
+ // If the initializer consists solely of a reference to itself, we
+ // explicitly mark the variable as uninitialized. This allows code
+ // like the following:
+ //
+ // int x = x;
+ //
+ // to deliberately leave a variable uninitialized. Different analysis
+ // clients can detect this pattern and adjust their reporting
+ // appropriately, but we need to continue to analyze subsequent uses
+ // of the variable.
+ if (init == lastLoad) {
+ const DeclRefExpr *DR
+ = cast<DeclRefExpr>(stripCasts(ac.getASTContext(),
+ lastLoad->getSubExpr()));
+ if (DR->getDecl() == vd) {
+ // int x = x;
+ // Propagate uninitialized value, but don't immediately report
+ // a problem.
+ vals[vd] = Uninitialized;
+ lastLoad = 0;
+ lastDR = 0;
+ if (handler)
+ handler->handleSelfInit(vd);
+ return;
+ }
+ }
+
+ // All other cases: treat the new variable as initialized.
+ // This is a minor optimization to reduce the propagation
+ // of the analysis, since we will have already reported
+ // the use of the uninitialized value (which visiting the
+ // initializer).
+ vals[vd] = Initialized;
+ }
+ }
+ }
+ }
+}
+
+void TransferFunctions::VisitBinaryOperator(clang::BinaryOperator *bo) {
+ if (bo->isAssignmentOp()) {
+ const FindVarResult &res = findBlockVarDecl(bo->getLHS());
+ if (const VarDecl *vd = res.getDecl()) {
+ ValueVector::reference val = vals[vd];
+ if (isUninitialized(val)) {
+ if (bo->getOpcode() != BO_Assign)
+ reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
+ else
+ val = Initialized;
+ }
+ }
+ }
+}
+
+void TransferFunctions::VisitUnaryOperator(clang::UnaryOperator *uo) {
+ switch (uo->getOpcode()) {
+ case clang::UO_PostDec:
+ case clang::UO_PostInc:
+ case clang::UO_PreDec:
+ case clang::UO_PreInc: {
+ const FindVarResult &res = findBlockVarDecl(uo->getSubExpr());
+ if (const VarDecl *vd = res.getDecl()) {
+ assert(res.getDeclRefExpr() == lastDR);
+ // We null out lastDR to indicate we have fully processed it
+ // and we don't want the auto-value setting in Visit().
+ lastDR = 0;
+
+ ValueVector::reference val = vals[vd];
+ if (isUninitialized(val))
+ reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
+ }
+ break;
+ }
+ default:
+ break;
+ }
+}
+
+void TransferFunctions::VisitCastExpr(clang::CastExpr *ce) {
+ if (ce->getCastKind() == CK_LValueToRValue) {
+ const FindVarResult &res = findBlockVarDecl(ce->getSubExpr());
+ if (res.getDecl()) {
+ assert(res.getDeclRefExpr() == lastDR);
+ lastLoad = ce;
+ }
+ }
+ else if (ce->getCastKind() == CK_NoOp ||
+ ce->getCastKind() == CK_LValueBitCast) {
+ skipProcessUses = true;
+ }
+ else if (CStyleCastExpr *cse = dyn_cast<CStyleCastExpr>(ce)) {
+ if (cse->getType()->isVoidType()) {
+ // e.g. (void) x;
+ if (lastLoad == cse->getSubExpr()) {
+ // Squelch any detected load of an uninitialized value if
+ // we cast it to void.
+ lastLoad = 0;
+ lastDR = 0;
+ }
+ }
+ }
+}
+
+void TransferFunctions::Visit(clang::Stmt *s) {
+ skipProcessUses = false;
+ StmtVisitor<TransferFunctions>::Visit(s);
+ if (!skipProcessUses)
+ ProcessUses(s);
+}
+
+void TransferFunctions::ProcessUses(Stmt *s) {
+ // This method is typically called after visiting a CFGElement statement
+ // in the CFG. We delay processing of reporting many loads of uninitialized
+ // values until here.
+ if (lastLoad) {
+ // If we just visited the lvalue-to-rvalue cast, there is nothing
+ // left to do.
+ if (lastLoad == s)
+ return;
+
+ const DeclRefExpr *DR =
+ cast<DeclRefExpr>(stripCasts(ac.getASTContext(),
+ lastLoad->getSubExpr()));
+ const VarDecl *VD = cast<VarDecl>(DR->getDecl());
+
+ // If we reach here, we may have seen a load of an uninitialized value
+ // and it hasn't been casted to void or otherwise handled. In this
+ // situation, report the incident.
+ if (isUninitialized(vals[VD]))
+ reportUninit(DR, VD, isAlwaysUninit(vals[VD]));
+
+ lastLoad = 0;
+
+ if (DR == lastDR) {
+ lastDR = 0;
+ return;
+ }
+ }
+
+ // Any other uses of 'lastDR' involve taking an lvalue of variable.
+ // In this case, it "escapes" the analysis.
+ if (lastDR && lastDR != s) {
+ vals[cast<VarDecl>(lastDR->getDecl())] = Initialized;
+ lastDR = 0;
+ }
+}
+
+//------------------------------------------------------------------------====//
+// High-level "driver" logic for uninitialized values analysis.
+//====------------------------------------------------------------------------//
+
+static bool runOnBlock(const CFGBlock *block, const CFG &cfg,
+ AnalysisDeclContext &ac, CFGBlockValues &vals,
+ llvm::BitVector &wasAnalyzed,
+ UninitVariablesHandler *handler = 0) {
+
+ wasAnalyzed[block->getBlockID()] = true;
+
+ if (const BinaryOperator *b = getLogicalOperatorInChain(block)) {
+ CFGBlock::const_pred_iterator itr = block->pred_begin();
+ BVPair vA = vals.getValueVectors(*itr, false);
+ ++itr;
+ BVPair vB = vals.getValueVectors(*itr, false);
+
+ BVPair valsAB;
+
+ if (b->getOpcode() == BO_LAnd) {
+ // Merge the 'F' bits from the first and second.
+ vals.mergeIntoScratch(*(vA.second ? vA.second : vA.first), true);
+ vals.mergeIntoScratch(*(vB.second ? vB.second : vB.first), false);
+ valsAB.first = vA.first;
+ valsAB.second = &vals.getScratch();
+ } else {
+ // Merge the 'T' bits from the first and second.
+ assert(b->getOpcode() == BO_LOr);
+ vals.mergeIntoScratch(*vA.first, true);
+ vals.mergeIntoScratch(*vB.first, false);
+ valsAB.first = &vals.getScratch();
+ valsAB.second = vA.second ? vA.second : vA.first;
+ }
+ return vals.updateValueVectors(block, valsAB);
+ }
+
+ // Default behavior: merge in values of predecessor blocks.
+ vals.resetScratch();
+ bool isFirst = true;
+ for (CFGBlock::const_pred_iterator I = block->pred_begin(),
+ E = block->pred_end(); I != E; ++I) {
+ const CFGBlock *pred = *I;
+ if (wasAnalyzed[pred->getBlockID()]) {
+ vals.mergeIntoScratch(vals.getValueVector(pred, block), isFirst);
+ isFirst = false;
+ }
+ }
+ // Apply the transfer function.
+ TransferFunctions tf(vals, cfg, ac, handler);
+ for (CFGBlock::const_iterator I = block->begin(), E = block->end();
+ I != E; ++I) {
+ if (const CFGStmt *cs = dyn_cast<CFGStmt>(&*I)) {
+ tf.Visit(const_cast<Stmt*>(cs->getStmt()));
+ }
+ }
+ tf.ProcessUses();
+ return vals.updateValueVectorWithScratch(block);
+}
+
+void clang::runUninitializedVariablesAnalysis(
+ const DeclContext &dc,
+ const CFG &cfg,
+ AnalysisDeclContext &ac,
+ UninitVariablesHandler &handler,
+ UninitVariablesAnalysisStats &stats) {
+ CFGBlockValues vals(cfg);
+ vals.computeSetOfDeclarations(dc);
+ if (vals.hasNoDeclarations())
+ return;
+
+ stats.NumVariablesAnalyzed = vals.getNumEntries();
+
+ // Mark all variables uninitialized at the entry.
+ const CFGBlock &entry = cfg.getEntry();
+ for (CFGBlock::const_succ_iterator i = entry.succ_begin(),
+ e = entry.succ_end(); i != e; ++i) {
+ if (const CFGBlock *succ = *i) {
+ ValueVector &vec = vals.getValueVector(&entry, succ);
+ const unsigned n = vals.getNumEntries();
+ for (unsigned j = 0; j < n ; ++j) {
+ vec[j] = Uninitialized;
+ }
+ }
+ }
+
+ // Proceed with the workist.
+ DataflowWorklist worklist(cfg);
+ llvm::BitVector previouslyVisited(cfg.getNumBlockIDs());
+ worklist.enqueueSuccessors(&cfg.getEntry());
+ llvm::BitVector wasAnalyzed(cfg.getNumBlockIDs(), false);
+ wasAnalyzed[cfg.getEntry().getBlockID()] = true;
+
+ while (const CFGBlock *block = worklist.dequeue()) {
+ // Did the block change?
+ bool changed = runOnBlock(block, cfg, ac, vals, wasAnalyzed);
+ ++stats.NumBlockVisits;
+ if (changed || !previouslyVisited[block->getBlockID()])
+ worklist.enqueueSuccessors(block);
+ previouslyVisited[block->getBlockID()] = true;
+ }
+
+ // Run through the blocks one more time, and report uninitialized variabes.
+ for (CFG::const_iterator BI = cfg.begin(), BE = cfg.end(); BI != BE; ++BI) {
+ const CFGBlock *block = *BI;
+ if (wasAnalyzed[block->getBlockID()]) {
+ runOnBlock(block, cfg, ac, vals, wasAnalyzed, &handler);
+ ++stats.NumBlockVisits;
+ }
+ }
+}
+
+UninitVariablesHandler::~UninitVariablesHandler() {}
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