[cfe-commits] r160494 - /cfe/trunk/lib/Analysis/UninitializedValues.cpp
Ted Kremenek
kremenek at apple.com
Wed Jul 18 21:59:06 PDT 2012
Author: kremenek
Date: Wed Jul 18 23:59:05 2012
New Revision: 160494
URL: http://llvm.org/viewvc/llvm-project?rev=160494&view=rev
Log:
Simplify UninitializedValues.cpp by removing logic to handle the previous (imprecise) representation
of '&&' and '||' in the CFG. This is no longer needed, and greatly simplifies the code.
Modified:
cfe/trunk/lib/Analysis/UninitializedValues.cpp
Modified: cfe/trunk/lib/Analysis/UninitializedValues.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/UninitializedValues.cpp?rev=160494&r1=160493&r2=160494&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/UninitializedValues.cpp (original)
+++ cfe/trunk/lib/Analysis/UninitializedValues.cpp Wed Jul 18 23:59:05 2012
@@ -98,38 +98,32 @@
namespace {
typedef llvm::PackedVector<Value, 2> ValueVector;
-typedef std::pair<ValueVector *, ValueVector *> BVPair;
class CFGBlockValues {
const CFG &cfg;
- BVPair *vals;
+ std::vector<ValueVector*> 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);
+ ValueVector &getValueVector(const CFGBlock *block) {
+ return *vals[block->getBlockID()];
+ }
void setAllScratchValues(Value V);
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);
@@ -137,91 +131,29 @@
const VarDecl *vd) {
const llvm::Optional<unsigned> &idx = declToIndex.getValueIndex(vd);
assert(idx.hasValue());
- return getValueVector(block, dstBlock)[idx.getValue()];
+ return getValueVector(block)[idx.getValue()];
}
};
} // 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(const CFG &c) : cfg(c), vals(0) {}
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;
+ for (std::vector<ValueVector*>::iterator I = vals.begin(), E = vals.end();
+ I != E; ++I)
+ delete *I;
}
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;
-
- CFGElement front = block->front();
- const CFGStmt *cstmt = 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];
+ unsigned decls = declToIndex.size();
+ scratch.resize(decls);
+ unsigned n = cfg.getNumBlockIDs();
+ if (!n)
+ return;
+ vals.resize(n);
+ for (unsigned i = 0; i < n; ++i)
+ vals[i] = new ValueVector(decls);
}
#if DEBUG_LOGGING
@@ -249,7 +181,7 @@
}
bool CFGBlockValues::updateValueVectorWithScratch(const CFGBlock *block) {
- ValueVector &dst = getValueVector(block, 0);
+ ValueVector &dst = getValueVector(block);
bool changed = (dst != scratch);
if (changed)
dst = scratch;
@@ -259,20 +191,6 @@
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 DEBUG_LOGGING
- printVector(block, *vals.first, 1);
- printVector(block, *vals.second, 2);
-#endif
- return changed;
-}
-
void CFGBlockValues::resetScratch() {
scratch.reset();
}
@@ -768,42 +686,15 @@
const ClassifyRefs &classification,
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();
+ // Merge in values of predecessor blocks.
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);
+ vals.mergeIntoScratch(vals.getValueVector(pred), isFirst);
isFirst = false;
}
}
@@ -828,9 +719,6 @@
vals.computeSetOfDeclarations(dc);
if (vals.hasNoDeclarations())
return;
-#if DEBUG_LOGGING
- cfg.dump(dc.getParentASTContext().getLangOpts(), true);
-#endif
stats.NumVariablesAnalyzed = vals.getNumEntries();
@@ -840,15 +728,10 @@
// 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;
- }
- }
+ ValueVector &vec = vals.getValueVector(&entry);
+ const unsigned n = vals.getNumEntries();
+ for (unsigned j = 0; j < n ; ++j) {
+ vec[j] = Uninitialized;
}
// Proceed with the workist.
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