r182083 - [analyzer; alternate edges] improve support for edges with PseudoObjectExprs.
Ted Kremenek
kremenek at apple.com
Fri May 17 02:41:41 PDT 2013
Author: kremenek
Date: Fri May 17 04:41:40 2013
New Revision: 182083
URL: http://llvm.org/viewvc/llvm-project?rev=182083&view=rev
Log:
[analyzer; alternate edges] improve support for edges with PseudoObjectExprs.
This optimizes some spurious edges resulting from PseudoObjectExprs.
This required far more changes than I anticipated. The current
ParentMap does not record any hierarchy information between
a PseudoObjectExpr and its *semantic* expressions that may be
wrapped in OpaqueValueExprs, which are the expressions actually
laid out in the CFG. This means the arrow pruning logic could
not map from an expression to its containing PseudoObjectExprs.
To solve this, this patch adds a variant of ParentMap that
returns the "semantic" parentage of expressions (essentially
as they are viewed by the CFG). This alternate ParentMap is then
used by the arrow reducing logic to identify edges into pseudo
object expressions, and then eliminate them.
Modified:
cfe/trunk/include/clang/AST/ParentMap.h
cfe/trunk/include/clang/Analysis/AnalysisContext.h
cfe/trunk/lib/AST/ParentMap.cpp
cfe/trunk/lib/Analysis/AnalysisDeclContext.cpp
cfe/trunk/lib/StaticAnalyzer/Core/BugReporter.cpp
Modified: cfe/trunk/include/clang/AST/ParentMap.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/ParentMap.h?rev=182083&r1=182082&r2=182083&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/ParentMap.h (original)
+++ cfe/trunk/include/clang/AST/ParentMap.h Fri May 17 04:41:40 2013
@@ -20,8 +20,9 @@ class Expr;
class ParentMap {
void* Impl;
+ bool IsSemantic;
public:
- ParentMap(Stmt* ASTRoot);
+ ParentMap(Stmt* ASTRoot, bool isSemantic = false);
~ParentMap();
/// \brief Adds and/or updates the parent/child-relations of the complete
Modified: cfe/trunk/include/clang/Analysis/AnalysisContext.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/AnalysisContext.h?rev=182083&r1=182082&r2=182083&view=diff
==============================================================================
--- cfe/trunk/include/clang/Analysis/AnalysisContext.h (original)
+++ cfe/trunk/include/clang/Analysis/AnalysisContext.h Fri May 17 04:41:40 2013
@@ -82,6 +82,7 @@ class AnalysisDeclContext {
bool builtCFG, builtCompleteCFG;
OwningPtr<ParentMap> PM;
+ OwningPtr<ParentMap> SemanticPM;
OwningPtr<PseudoConstantAnalysis> PCA;
OwningPtr<CFGReverseBlockReachabilityAnalysis> CFA;
@@ -165,6 +166,9 @@ public:
bool isCFGBuilt() const { return builtCFG; }
ParentMap &getParentMap();
+
+ ParentMap &getSemanticParentMap();
+
PseudoConstantAnalysis *getPseudoConstantAnalysis();
typedef const VarDecl * const * referenced_decls_iterator;
@@ -245,6 +249,10 @@ public:
return getAnalysisDeclContext()->getParentMap();
}
+ ParentMap &getSemanticParentMap() const {
+ return getAnalysisDeclContext()->getSemanticParentMap();
+ }
+
const ImplicitParamDecl *getSelfDecl() const {
return Ctx->getSelfDecl();
}
Modified: cfe/trunk/lib/AST/ParentMap.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ParentMap.cpp?rev=182083&r1=182082&r2=182083&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ParentMap.cpp (original)
+++ cfe/trunk/lib/AST/ParentMap.cpp Fri May 17 04:41:40 2013
@@ -25,7 +25,7 @@ enum OpaqueValueMode {
OV_Opaque
};
-static void BuildParentMap(MapTy& M, Stmt* S,
+static void BuildParentMap(MapTy& M, Stmt* S, bool isSemantic,
OpaqueValueMode OVMode = OV_Transparent) {
switch (S->getStmtClass()) {
@@ -33,14 +33,17 @@ static void BuildParentMap(MapTy& M, Stm
assert(OVMode == OV_Transparent && "Should not appear alongside OVEs");
PseudoObjectExpr *POE = cast<PseudoObjectExpr>(S);
- M[POE->getSyntacticForm()] = S;
- BuildParentMap(M, POE->getSyntacticForm(), OV_Transparent);
+ if (!isSemantic) {
+ M[POE->getSyntacticForm()] = S;
+ BuildParentMap(M, POE->getSyntacticForm(), OV_Transparent);
+ }
for (PseudoObjectExpr::semantics_iterator I = POE->semantics_begin(),
E = POE->semantics_end();
I != E; ++I) {
M[*I] = S;
- BuildParentMap(M, *I, OV_Opaque);
+ BuildParentMap(M, *I, isSemantic,
+ isSemantic ? OV_Transparent : OV_Opaque);
}
break;
}
@@ -49,16 +52,16 @@ static void BuildParentMap(MapTy& M, Stm
BinaryConditionalOperator *BCO = cast<BinaryConditionalOperator>(S);
M[BCO->getCommon()] = S;
- BuildParentMap(M, BCO->getCommon(), OV_Transparent);
+ BuildParentMap(M, BCO->getCommon(), isSemantic, OV_Transparent);
M[BCO->getCond()] = S;
- BuildParentMap(M, BCO->getCond(), OV_Opaque);
+ BuildParentMap(M, BCO->getCond(), isSemantic, OV_Opaque);
M[BCO->getTrueExpr()] = S;
- BuildParentMap(M, BCO->getTrueExpr(), OV_Opaque);
+ BuildParentMap(M, BCO->getTrueExpr(), isSemantic, OV_Opaque);
M[BCO->getFalseExpr()] = S;
- BuildParentMap(M, BCO->getFalseExpr(), OV_Transparent);
+ BuildParentMap(M, BCO->getFalseExpr(), isSemantic, OV_Transparent);
break;
}
@@ -66,24 +69,25 @@ static void BuildParentMap(MapTy& M, Stm
if (OVMode == OV_Transparent) {
OpaqueValueExpr *OVE = cast<OpaqueValueExpr>(S);
M[OVE->getSourceExpr()] = S;
- BuildParentMap(M, OVE->getSourceExpr(), OV_Transparent);
+ BuildParentMap(M, OVE->getSourceExpr(), isSemantic, OV_Transparent);
}
break;
default:
for (Stmt::child_range I = S->children(); I; ++I) {
if (*I) {
M[*I] = S;
- BuildParentMap(M, *I, OVMode);
+ BuildParentMap(M, *I, isSemantic, OVMode);
}
}
break;
}
}
-ParentMap::ParentMap(Stmt* S) : Impl(0) {
+ParentMap::ParentMap(Stmt* S, bool isSemantic) : Impl(0),
+ IsSemantic(isSemantic) {
if (S) {
MapTy *M = new MapTy();
- BuildParentMap(*M, S);
+ BuildParentMap(*M, S, isSemantic);
Impl = M;
}
}
@@ -94,7 +98,7 @@ ParentMap::~ParentMap() {
void ParentMap::addStmt(Stmt* S) {
if (S) {
- BuildParentMap(*(MapTy*) Impl, S);
+ BuildParentMap(*(MapTy*) Impl, S, IsSemantic);
}
}
Modified: cfe/trunk/lib/Analysis/AnalysisDeclContext.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/AnalysisDeclContext.cpp?rev=182083&r1=182082&r2=182083&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/AnalysisDeclContext.cpp (original)
+++ cfe/trunk/lib/Analysis/AnalysisDeclContext.cpp Fri May 17 04:41:40 2013
@@ -212,20 +212,34 @@ void AnalysisDeclContext::dumpCFG(bool S
getCFG()->dump(getASTContext().getLangOpts(), ShowColors);
}
+static ParentMap *constructParentMap(bool isSemantic,
+ Stmt *Body,
+ const Decl *D) {
+ ParentMap *PM = new ParentMap(Body, isSemantic);
+ if (const CXXConstructorDecl *C = dyn_cast<CXXConstructorDecl>(D)) {
+ for (CXXConstructorDecl::init_const_iterator I = C->init_begin(),
+ E = C->init_end();
+ I != E; ++I) {
+ PM->addStmt((*I)->getInit());
+ }
+ }
+ return PM;
+}
+
ParentMap &AnalysisDeclContext::getParentMap() {
if (!PM) {
- PM.reset(new ParentMap(getBody()));
- if (const CXXConstructorDecl *C = dyn_cast<CXXConstructorDecl>(getDecl())) {
- for (CXXConstructorDecl::init_const_iterator I = C->init_begin(),
- E = C->init_end();
- I != E; ++I) {
- PM->addStmt((*I)->getInit());
- }
- }
+ PM.reset(constructParentMap(false, getBody(), getDecl()));
}
return *PM;
}
+ParentMap &AnalysisDeclContext::getSemanticParentMap() {
+ if (!SemanticPM) {
+ SemanticPM.reset(constructParentMap(true, getBody(), getDecl()));
+ }
+ return *SemanticPM;
+}
+
PseudoConstantAnalysis *AnalysisDeclContext::getPseudoConstantAnalysis() {
if (!PCA)
PCA.reset(new PseudoConstantAnalysis(getBody()));
Modified: cfe/trunk/lib/StaticAnalyzer/Core/BugReporter.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/BugReporter.cpp?rev=182083&r1=182082&r2=182083&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/BugReporter.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/BugReporter.cpp Fri May 17 04:41:40 2013
@@ -1873,9 +1873,78 @@ static bool isIncrementOrInitInForLoop(c
typedef llvm::DenseSet<const PathDiagnosticCallPiece *>
OptimizedCallsSet;
+typedef llvm::DenseMap<const Stmt *,
+ Optional<const PseudoObjectExpr *> >
+ PseudoObjectExprMap;
+
+/// Return the PseudoObjectExpr that contains this statement (if any).
+static const PseudoObjectExpr *
+getContainingPseudoObjectExpr(PseudoObjectExprMap &PEM,
+ ParentMap &PM,
+ const Stmt *S) {
+ if (!S)
+ return 0;
+
+ Optional<const PseudoObjectExpr *> &Entry = PEM[S];
+ if (!Entry.hasValue()) {
+ const Stmt *Parent = PM.getParentIgnoreParens(S);
+ if (const PseudoObjectExpr *PE = dyn_cast_or_null<PseudoObjectExpr>(Parent))
+ Entry = PE;
+ else
+ Entry = getContainingPseudoObjectExpr(PEM, PM, Parent);
+ }
+ return Entry.getValue();
+}
+
+#if 0
+static void printPath(PathPieces &path, ParentMap &PM) {
+ unsigned index = 0;
+ for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I ) {
+ llvm::errs() << "[" << index++ << "]\n";
+ if (isa<PathDiagnosticCallPiece>(*I)) {
+ llvm::errs() << " CALL\n";
+ continue;
+ }
+ if (isa<PathDiagnosticEventPiece>(*I)) {
+ llvm::errs() << " EVENT\n";
+ continue;
+ }
+ if (const PathDiagnosticControlFlowPiece *CP = dyn_cast<PathDiagnosticControlFlowPiece>(*I)) {
+ llvm::errs() << " CONTROL\n";
+ const Stmt *s1Start = getLocStmt(CP->getStartLocation());
+ const Stmt *s1End = getLocStmt(CP->getEndLocation());
+ if (s1Start) {
+ s1Start->dump();
+ llvm::errs() << "PARENT: \n";
+ const Stmt *Parent = getStmtParent(s1Start, PM);
+ if (Parent) {
+ Parent->dump();
+ }
+ }
+ else {
+ llvm::errs() << "NULL\n";
+ }
+ llvm::errs() << " --------- ===== ----- \n";
+ if (s1End) {
+ s1End->dump();
+ llvm::errs() << "PARENT: \n";
+ const Stmt *Parent = getStmtParent(s1End, PM);
+ if (Parent) {
+ Parent->dump();
+ }
+ }
+ else {
+ llvm::errs() << "NULL\n";
+ }
+ }
+ }
+}
+#endif
+
static bool optimizeEdges(PathPieces &path, SourceManager &SM,
OptimizedCallsSet &OCS,
- LocationContextMap &LCM) {
+ LocationContextMap &LCM,
+ PseudoObjectExprMap &PEM) {
bool hasChanges = false;
const LocationContext *LC = LCM[&path];
assert(LC);
@@ -1890,7 +1959,7 @@ static bool optimizeEdges(PathPieces &pa
// Record the fact that a call has been optimized so we only do the
// effort once.
if (!OCS.count(CallI)) {
- while (optimizeEdges(CallI->path, SM, OCS, LCM)) {}
+ while (optimizeEdges(CallI->path, SM, OCS, LCM, PEM)) {}
OCS.insert(CallI);
}
++I;
@@ -1906,7 +1975,7 @@ static bool optimizeEdges(PathPieces &pa
continue;
}
- ParentMap &PM = LC->getParentMap();
+ ParentMap &PM = LC->getSemanticParentMap();
const Stmt *s1Start = getLocStmt(PieceI->getStartLocation());
const Stmt *s1End = getLocStmt(PieceI->getEndLocation());
const Stmt *level1 = getStmtParent(s1Start, PM);
@@ -1933,6 +2002,39 @@ static bool optimizeEdges(PathPieces &pa
}
}
+ // Prune out edges for pseudo object expressions.
+ //
+ // Case 1: incoming into a pseudo expr.
+ //
+ // An edge into a subexpression of a pseudo object expression
+ // should be replaced with an edge to the pseudo object expression
+ // itself.
+ const PseudoObjectExpr *PE = getContainingPseudoObjectExpr(PEM, PM, s1End);
+ if (PE) {
+ PathDiagnosticLocation L(PE, SM, LC);
+ PieceI->setEndLocation(L);
+ // Do not increment the iterator. It is possible we will match again.
+ hasChanges = true;
+ continue;
+ }
+
+ // Prune out edges for pseudo object expressions.
+ //
+ // Case 2: outgoing from a pseudo expr.
+ //
+ // An edge into a subexpression of a pseudo object expression
+ // should be replaced with an edge to the pseudo object expression
+ // itself.
+ PE = getContainingPseudoObjectExpr(PEM, PM, s1Start);
+ if (PE) {
+ PathDiagnosticLocation L(PE, SM, LC);
+ PieceI->setStartLocation(L);
+ // Do not increment the iterator. It is possible we will match again.
+ hasChanges = true;
+ continue;
+ }
+
+ // Pattern match on two edges after this point.
PathPieces::iterator NextI = I; ++NextI;
if (NextI == E)
break;
@@ -2782,7 +2884,8 @@ bool GRBugReporter::generatePathDiagnost
// to an aesthetically pleasing subset that conveys the
// necessary information.
OptimizedCallsSet OCS;
- while (optimizeEdges(PD.getMutablePieces(), SM, OCS, LCM)) {}
+ PseudoObjectExprMap PEM;
+ while (optimizeEdges(PD.getMutablePieces(), SM, OCS, LCM, PEM)) {}
// Adjust edges into loop conditions to make them more uniform
// and aesthetically pleasing.
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