r363509 - [analyzer][NFC] Tease apart and clang-format NoStoreFuncVisitor
Kristof Umann via cfe-commits
cfe-commits at lists.llvm.org
Sun Jun 16 07:09:12 PDT 2019
Author: szelethus
Date: Sun Jun 16 07:09:11 2019
New Revision: 363509
URL: http://llvm.org/viewvc/llvm-project?rev=363509&view=rev
Log:
[analyzer][NFC] Tease apart and clang-format NoStoreFuncVisitor
Make several methods static functions
Move non-trivial methods out-of-line
Add a divider
Turn non-obvious autos into Optional<RegionVector>
clang-format affected lines
Differential Revision: https://reviews.llvm.org/D63086
Modified:
cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
Modified: cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp?rev=363509&r1=363508&r2=363509&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp Sun Jun 16 07:09:11 2019
@@ -196,37 +196,6 @@ getConcreteIntegerValue(const Expr *Cond
return {};
}
-//===----------------------------------------------------------------------===//
-// Implementation of BugReporterVisitor.
-//===----------------------------------------------------------------------===//
-
-std::shared_ptr<PathDiagnosticPiece>
-BugReporterVisitor::getEndPath(BugReporterContext &,
- const ExplodedNode *, BugReport &) {
- return nullptr;
-}
-
-void
-BugReporterVisitor::finalizeVisitor(BugReporterContext &,
- const ExplodedNode *, BugReport &) {}
-
-std::shared_ptr<PathDiagnosticPiece> BugReporterVisitor::getDefaultEndPath(
- BugReporterContext &BRC, const ExplodedNode *EndPathNode, BugReport &BR) {
- PathDiagnosticLocation L =
- PathDiagnosticLocation::createEndOfPath(EndPathNode,BRC.getSourceManager());
-
- const auto &Ranges = BR.getRanges();
-
- // Only add the statement itself as a range if we didn't specify any
- // special ranges for this report.
- auto P = std::make_shared<PathDiagnosticEventPiece>(
- L, BR.getDescription(), Ranges.begin() == Ranges.end());
- for (SourceRange Range : Ranges)
- P->addRange(Range);
-
- return P;
-}
-
/// \return name of the macro inside the location \p Loc.
static StringRef getMacroName(SourceLocation Loc,
BugReporterContext &BRC) {
@@ -251,36 +220,70 @@ static bool isFunctionMacroExpansion(Sou
}
/// \return Whether \c RegionOfInterest was modified at \p N,
-/// where \p ReturnState is a state associated with the return
-/// from the current frame.
-static bool wasRegionOfInterestModifiedAt(
- const SubRegion *RegionOfInterest,
- const ExplodedNode *N,
- SVal ValueAfter) {
+/// where \p ValueAfter is \c RegionOfInterest's value at the end of the
+/// stack frame.
+static bool wasRegionOfInterestModifiedAt(const SubRegion *RegionOfInterest,
+ const ExplodedNode *N,
+ SVal ValueAfter) {
ProgramStateRef State = N->getState();
ProgramStateManager &Mgr = N->getState()->getStateManager();
- if (!N->getLocationAs<PostStore>()
- && !N->getLocationAs<PostInitializer>()
- && !N->getLocationAs<PostStmt>())
+ if (!N->getLocationAs<PostStore>() && !N->getLocationAs<PostInitializer>() &&
+ !N->getLocationAs<PostStmt>())
return false;
// Writing into region of interest.
if (auto PS = N->getLocationAs<PostStmt>())
if (auto *BO = PS->getStmtAs<BinaryOperator>())
if (BO->isAssignmentOp() && RegionOfInterest->isSubRegionOf(
- N->getSVal(BO->getLHS()).getAsRegion()))
+ N->getSVal(BO->getLHS()).getAsRegion()))
return true;
// SVal after the state is possibly different.
SVal ValueAtN = N->getState()->getSVal(RegionOfInterest);
- if (!Mgr.getSValBuilder().areEqual(State, ValueAtN, ValueAfter).isConstrainedTrue() &&
+ if (!Mgr.getSValBuilder()
+ .areEqual(State, ValueAtN, ValueAfter)
+ .isConstrainedTrue() &&
(!ValueAtN.isUndef() || !ValueAfter.isUndef()))
return true;
return false;
}
+//===----------------------------------------------------------------------===//
+// Implementation of BugReporterVisitor.
+//===----------------------------------------------------------------------===//
+
+std::shared_ptr<PathDiagnosticPiece>
+BugReporterVisitor::getEndPath(BugReporterContext &,
+ const ExplodedNode *, BugReport &) {
+ return nullptr;
+}
+
+void
+BugReporterVisitor::finalizeVisitor(BugReporterContext &,
+ const ExplodedNode *, BugReport &) {}
+
+std::shared_ptr<PathDiagnosticPiece> BugReporterVisitor::getDefaultEndPath(
+ BugReporterContext &BRC, const ExplodedNode *EndPathNode, BugReport &BR) {
+ PathDiagnosticLocation L =
+ PathDiagnosticLocation::createEndOfPath(EndPathNode,BRC.getSourceManager());
+
+ const auto &Ranges = BR.getRanges();
+
+ // Only add the statement itself as a range if we didn't specify any
+ // special ranges for this report.
+ auto P = std::make_shared<PathDiagnosticEventPiece>(
+ L, BR.getDescription(), Ranges.begin() == Ranges.end());
+ for (SourceRange Range : Ranges)
+ P->addRange(Range);
+
+ return P;
+}
+
+//===----------------------------------------------------------------------===//
+// Implementation of NoStoreFuncVisitor.
+//===----------------------------------------------------------------------===//
namespace {
@@ -311,6 +314,7 @@ class NoStoreFuncVisitor final : public
llvm::SmallPtrSet<const StackFrameContext *, 32> FramesModifyingCalculated;
using RegionVector = SmallVector<const MemRegion *, 5>;
+
public:
NoStoreFuncVisitor(const SubRegion *R)
: RegionOfInterest(R), MmrMgr(*R->getMemRegionManager()),
@@ -330,78 +334,10 @@ public:
std::shared_ptr<PathDiagnosticPiece> VisitNode(const ExplodedNode *N,
BugReporterContext &BR,
- BugReport &R) override {
-
- const LocationContext *Ctx = N->getLocationContext();
- const StackFrameContext *SCtx = Ctx->getStackFrame();
- ProgramStateRef State = N->getState();
- auto CallExitLoc = N->getLocationAs<CallExitBegin>();
-
- // No diagnostic if region was modified inside the frame.
- if (!CallExitLoc || isRegionOfInterestModifiedInFrame(N))
- return nullptr;
-
- CallEventRef<> Call =
- BR.getStateManager().getCallEventManager().getCaller(SCtx, State);
-
- // Region of interest corresponds to an IVar, exiting a method
- // which could have written into that IVar, but did not.
- if (const auto *MC = dyn_cast<ObjCMethodCall>(Call)) {
- if (const auto *IvarR = dyn_cast<ObjCIvarRegion>(RegionOfInterest)) {
- const MemRegion *SelfRegion = MC->getReceiverSVal().getAsRegion();
- if (RegionOfInterest->isSubRegionOf(SelfRegion) &&
- potentiallyWritesIntoIvar(Call->getRuntimeDefinition().getDecl(),
- IvarR->getDecl()))
- return maybeEmitNote(R, *Call, N, {}, SelfRegion, "self",
- /*FirstIsReferenceType=*/false, 1);
- }
- }
-
- if (const auto *CCall = dyn_cast<CXXConstructorCall>(Call)) {
- const MemRegion *ThisR = CCall->getCXXThisVal().getAsRegion();
- if (RegionOfInterest->isSubRegionOf(ThisR)
- && !CCall->getDecl()->isImplicit())
- return maybeEmitNote(R, *Call, N, {}, ThisR, "this",
- /*FirstIsReferenceType=*/false, 1);
-
- // Do not generate diagnostics for not modified parameters in
- // constructors.
- return nullptr;
- }
-
- ArrayRef<ParmVarDecl *> parameters = getCallParameters(Call);
- for (unsigned I = 0; I < Call->getNumArgs() && I < parameters.size(); ++I) {
- const ParmVarDecl *PVD = parameters[I];
- SVal V = Call->getArgSVal(I);
- bool ParamIsReferenceType = PVD->getType()->isReferenceType();
- std::string ParamName = PVD->getNameAsString();
-
- int IndirectionLevel = 1;
- QualType T = PVD->getType();
- while (const MemRegion *MR = V.getAsRegion()) {
- if (RegionOfInterest->isSubRegionOf(MR) && !isPointerToConst(T))
- return maybeEmitNote(R, *Call, N, {}, MR, ParamName,
- ParamIsReferenceType, IndirectionLevel);
-
- QualType PT = T->getPointeeType();
- if (PT.isNull() || PT->isVoidType()) break;
-
- if (const RecordDecl *RD = PT->getAsRecordDecl())
- if (auto P = findRegionOfInterestInRecord(RD, State, MR))
- return maybeEmitNote(R, *Call, N, *P, RegionOfInterest, ParamName,
- ParamIsReferenceType, IndirectionLevel);
-
- V = State->getSVal(MR, PT);
- T = PT;
- IndirectionLevel++;
- }
- }
-
- return nullptr;
- }
+ BugReport &R) override;
private:
- /// Attempts to find the region of interest in a given CXX decl,
+ /// Attempts to find the region of interest in a given record decl,
/// by either following the base classes or fields.
/// Dereferences fields up to a given recursion limit.
/// Note that \p Vec is passed by value, leading to quadratic copying cost,
@@ -409,87 +345,8 @@ private:
/// \return A chain fields leading to the region of interest or None.
const Optional<RegionVector>
findRegionOfInterestInRecord(const RecordDecl *RD, ProgramStateRef State,
- const MemRegion *R,
- const RegionVector &Vec = {},
- int depth = 0) {
-
- if (depth == DEREFERENCE_LIMIT) // Limit the recursion depth.
- return None;
-
- if (const auto *RDX = dyn_cast<CXXRecordDecl>(RD))
- if (!RDX->hasDefinition())
- return None;
-
- // Recursively examine the base classes.
- // Note that following base classes does not increase the recursion depth.
- if (const auto *RDX = dyn_cast<CXXRecordDecl>(RD))
- for (const auto II : RDX->bases())
- if (const RecordDecl *RRD = II.getType()->getAsRecordDecl())
- if (auto Out = findRegionOfInterestInRecord(RRD, State, R, Vec, depth))
- return Out;
-
- for (const FieldDecl *I : RD->fields()) {
- QualType FT = I->getType();
- const FieldRegion *FR = MmrMgr.getFieldRegion(I, cast<SubRegion>(R));
- const SVal V = State->getSVal(FR);
- const MemRegion *VR = V.getAsRegion();
-
- RegionVector VecF = Vec;
- VecF.push_back(FR);
-
- if (RegionOfInterest == VR)
- return VecF;
-
- if (const RecordDecl *RRD = FT->getAsRecordDecl())
- if (auto Out =
- findRegionOfInterestInRecord(RRD, State, FR, VecF, depth + 1))
- return Out;
-
- QualType PT = FT->getPointeeType();
- if (PT.isNull() || PT->isVoidType() || !VR) continue;
-
- if (const RecordDecl *RRD = PT->getAsRecordDecl())
- if (auto Out =
- findRegionOfInterestInRecord(RRD, State, VR, VecF, depth + 1))
- return Out;
-
- }
-
- return None;
- }
-
- /// \return Whether the method declaration \p Parent
- /// syntactically has a binary operation writing into the ivar \p Ivar.
- bool potentiallyWritesIntoIvar(const Decl *Parent,
- const ObjCIvarDecl *Ivar) {
- using namespace ast_matchers;
- const char * IvarBind = "Ivar";
- if (!Parent || !Parent->hasBody())
- return false;
- StatementMatcher WriteIntoIvarM = binaryOperator(
- hasOperatorName("="),
- hasLHS(ignoringParenImpCasts(
- objcIvarRefExpr(hasDeclaration(equalsNode(Ivar))).bind(IvarBind))));
- StatementMatcher ParentM = stmt(hasDescendant(WriteIntoIvarM));
- auto Matches = match(ParentM, *Parent->getBody(), Parent->getASTContext());
- for (BoundNodes &Match : Matches) {
- auto IvarRef = Match.getNodeAs<ObjCIvarRefExpr>(IvarBind);
- if (IvarRef->isFreeIvar())
- return true;
-
- const Expr *Base = IvarRef->getBase();
- if (const auto *ICE = dyn_cast<ImplicitCastExpr>(Base))
- Base = ICE->getSubExpr();
-
- if (const auto *DRE = dyn_cast<DeclRefExpr>(Base))
- if (const auto *ID = dyn_cast<ImplicitParamDecl>(DRE->getDecl()))
- if (ID->getParameterKind() == ImplicitParamDecl::ObjCSelf)
- return true;
-
- return false;
- }
- return false;
- }
+ const MemRegion *R, const RegionVector &Vec = {},
+ int depth = 0);
/// Check and lazily calculate whether the region of interest is
/// modified in the stack frame to which \p N belongs.
@@ -502,64 +359,9 @@ private:
return FramesModifyingRegion.count(SCtx);
}
-
/// Write to \c FramesModifyingRegion all stack frames along
/// the path in the current stack frame which modify \c RegionOfInterest.
- void findModifyingFrames(const ExplodedNode *N) {
- assert(N->getLocationAs<CallExitBegin>());
- ProgramStateRef LastReturnState = N->getState();
- SVal ValueAtReturn = LastReturnState->getSVal(RegionOfInterest);
- const LocationContext *Ctx = N->getLocationContext();
- const StackFrameContext *OriginalSCtx = Ctx->getStackFrame();
-
- do {
- ProgramStateRef State = N->getState();
- auto CallExitLoc = N->getLocationAs<CallExitBegin>();
- if (CallExitLoc) {
- LastReturnState = State;
- ValueAtReturn = LastReturnState->getSVal(RegionOfInterest);
- }
-
- FramesModifyingCalculated.insert(
- N->getLocationContext()->getStackFrame());
-
- if (wasRegionOfInterestModifiedAt(RegionOfInterest, N, ValueAtReturn)) {
- const StackFrameContext *SCtx = N->getStackFrame();
- while (!SCtx->inTopFrame()) {
- auto p = FramesModifyingRegion.insert(SCtx);
- if (!p.second)
- break; // Frame and all its parents already inserted.
- SCtx = SCtx->getParent()->getStackFrame();
- }
- }
-
- // Stop calculation at the call to the current function.
- if (auto CE = N->getLocationAs<CallEnter>())
- if (CE->getCalleeContext() == OriginalSCtx)
- break;
-
- N = N->getFirstPred();
- } while (N);
- }
-
- /// Get parameters associated with runtime definition in order
- /// to get the correct parameter name.
- ArrayRef<ParmVarDecl *> getCallParameters(CallEventRef<> Call) {
- // Use runtime definition, if available.
- RuntimeDefinition RD = Call->getRuntimeDefinition();
- if (const auto *FD = dyn_cast_or_null<FunctionDecl>(RD.getDecl()))
- return FD->parameters();
- if (const auto *MD = dyn_cast_or_null<ObjCMethodDecl>(RD.getDecl()))
- return MD->parameters();
-
- return Call->parameters();
- }
-
- /// \return whether \p Ty points to a const type, or is a const reference.
- bool isPointerToConst(QualType Ty) {
- return !Ty->getPointeeType().isNull() &&
- Ty->getPointeeType().getCanonicalType().isConstQualified();
- }
+ void findModifyingFrames(const ExplodedNode *N);
/// Consume the information on the no-store stack frame in order to
/// either emit a note or suppress the report enirely.
@@ -569,50 +371,7 @@ private:
maybeEmitNote(BugReport &R, const CallEvent &Call, const ExplodedNode *N,
const RegionVector &FieldChain, const MemRegion *MatchedRegion,
StringRef FirstElement, bool FirstIsReferenceType,
- unsigned IndirectionLevel) {
- // Optimistically suppress uninitialized value bugs that result
- // from system headers having a chance to initialize the value
- // but failing to do so. It's too unlikely a system header's fault.
- // It's much more likely a situation in which the function has a failure
- // mode that the user decided not to check. If we want to hunt such
- // omitted checks, we should provide an explicit function-specific note
- // describing the precondition under which the function isn't supposed to
- // initialize its out-parameter, and additionally check that such
- // precondition can actually be fulfilled on the current path.
- if (Call.isInSystemHeader()) {
- // We make an exception for system header functions that have no branches.
- // Such functions unconditionally fail to initialize the variable.
- // If they call other functions that have more paths within them,
- // this suppression would still apply when we visit these inner functions.
- // One common example of a standard function that doesn't ever initialize
- // its out parameter is operator placement new; it's up to the follow-up
- // constructor (if any) to initialize the memory.
- if (!N->getStackFrame()->getCFG()->isLinear())
- R.markInvalid(getTag(), nullptr);
- return nullptr;
- }
-
- PathDiagnosticLocation L =
- PathDiagnosticLocation::create(N->getLocation(), SM);
-
- // For now this shouldn't trigger, but once it does (as we add more
- // functions to the body farm), we'll need to decide if these reports
- // are worth suppressing as well.
- if (!L.hasValidLocation())
- return nullptr;
-
- SmallString<256> sbuf;
- llvm::raw_svector_ostream os(sbuf);
- os << "Returning without writing to '";
-
- // Do not generate the note if failed to pretty-print.
- if (!prettyPrintRegionName(FirstElement, FirstIsReferenceType,
- MatchedRegion, FieldChain, IndirectionLevel, os))
- return nullptr;
-
- os << "'";
- return std::make_shared<PathDiagnosticEventPiece>(L, os.str());
- }
+ unsigned IndirectionLevel);
/// Pretty-print region \p MatchedRegion to \p os.
/// \return Whether printing succeeded.
@@ -620,81 +379,364 @@ private:
const MemRegion *MatchedRegion,
const RegionVector &FieldChain,
int IndirectionLevel,
- llvm::raw_svector_ostream &os) {
+ llvm::raw_svector_ostream &os);
- if (FirstIsReferenceType)
- IndirectionLevel--;
+ /// Print first item in the chain, return new separator.
+ static StringRef prettyPrintFirstElement(StringRef FirstElement,
+ bool MoreItemsExpected,
+ int IndirectionLevel,
+ llvm::raw_svector_ostream &os);
+};
- RegionVector RegionSequence;
+} // end of anonymous namespace
- // Add the regions in the reverse order, then reverse the resulting array.
- assert(RegionOfInterest->isSubRegionOf(MatchedRegion));
- const MemRegion *R = RegionOfInterest;
- while (R != MatchedRegion) {
- RegionSequence.push_back(R);
- R = cast<SubRegion>(R)->getSuperRegion();
- }
- std::reverse(RegionSequence.begin(), RegionSequence.end());
- RegionSequence.append(FieldChain.begin(), FieldChain.end());
+/// \return Whether the method declaration \p Parent
+/// syntactically has a binary operation writing into the ivar \p Ivar.
+static bool potentiallyWritesIntoIvar(const Decl *Parent,
+ const ObjCIvarDecl *Ivar) {
+ using namespace ast_matchers;
+ const char *IvarBind = "Ivar";
+ if (!Parent || !Parent->hasBody())
+ return false;
+ StatementMatcher WriteIntoIvarM = binaryOperator(
+ hasOperatorName("="),
+ hasLHS(ignoringParenImpCasts(
+ objcIvarRefExpr(hasDeclaration(equalsNode(Ivar))).bind(IvarBind))));
+ StatementMatcher ParentM = stmt(hasDescendant(WriteIntoIvarM));
+ auto Matches = match(ParentM, *Parent->getBody(), Parent->getASTContext());
+ for (BoundNodes &Match : Matches) {
+ auto IvarRef = Match.getNodeAs<ObjCIvarRefExpr>(IvarBind);
+ if (IvarRef->isFreeIvar())
+ return true;
+
+ const Expr *Base = IvarRef->getBase();
+ if (const auto *ICE = dyn_cast<ImplicitCastExpr>(Base))
+ Base = ICE->getSubExpr();
+
+ if (const auto *DRE = dyn_cast<DeclRefExpr>(Base))
+ if (const auto *ID = dyn_cast<ImplicitParamDecl>(DRE->getDecl()))
+ if (ID->getParameterKind() == ImplicitParamDecl::ObjCSelf)
+ return true;
+
+ return false;
+ }
+ return false;
+}
+
+/// Get parameters associated with runtime definition in order
+/// to get the correct parameter name.
+static ArrayRef<ParmVarDecl *> getCallParameters(CallEventRef<> Call) {
+ // Use runtime definition, if available.
+ RuntimeDefinition RD = Call->getRuntimeDefinition();
+ if (const auto *FD = dyn_cast_or_null<FunctionDecl>(RD.getDecl()))
+ return FD->parameters();
+ if (const auto *MD = dyn_cast_or_null<ObjCMethodDecl>(RD.getDecl()))
+ return MD->parameters();
+
+ return Call->parameters();
+}
+
+/// \return whether \p Ty points to a const type, or is a const reference.
+static bool isPointerToConst(QualType Ty) {
+ return !Ty->getPointeeType().isNull() &&
+ Ty->getPointeeType().getCanonicalType().isConstQualified();
+}
+
+/// Attempts to find the region of interest in a given CXX decl,
+/// by either following the base classes or fields.
+/// Dereferences fields up to a given recursion limit.
+/// Note that \p Vec is passed by value, leading to quadratic copying cost,
+/// but it's OK in practice since its length is limited to DEREFERENCE_LIMIT.
+/// \return A chain fields leading to the region of interest or None.
+const Optional<NoStoreFuncVisitor::RegionVector>
+NoStoreFuncVisitor::findRegionOfInterestInRecord(
+ const RecordDecl *RD, ProgramStateRef State, const MemRegion *R,
+ const NoStoreFuncVisitor::RegionVector &Vec /* = {} */,
+ int depth /* = 0 */) {
+
+ if (depth == DEREFERENCE_LIMIT) // Limit the recursion depth.
+ return None;
+
+ if (const auto *RDX = dyn_cast<CXXRecordDecl>(RD))
+ if (!RDX->hasDefinition())
+ return None;
+
+ // Recursively examine the base classes.
+ // Note that following base classes does not increase the recursion depth.
+ if (const auto *RDX = dyn_cast<CXXRecordDecl>(RD))
+ for (const auto II : RDX->bases())
+ if (const RecordDecl *RRD = II.getType()->getAsRecordDecl())
+ if (Optional<RegionVector> Out =
+ findRegionOfInterestInRecord(RRD, State, R, Vec, depth))
+ return Out;
+
+ for (const FieldDecl *I : RD->fields()) {
+ QualType FT = I->getType();
+ const FieldRegion *FR = MmrMgr.getFieldRegion(I, cast<SubRegion>(R));
+ const SVal V = State->getSVal(FR);
+ const MemRegion *VR = V.getAsRegion();
+
+ RegionVector VecF = Vec;
+ VecF.push_back(FR);
+
+ if (RegionOfInterest == VR)
+ return VecF;
+
+ if (const RecordDecl *RRD = FT->getAsRecordDecl())
+ if (auto Out =
+ findRegionOfInterestInRecord(RRD, State, FR, VecF, depth + 1))
+ return Out;
+
+ QualType PT = FT->getPointeeType();
+ if (PT.isNull() || PT->isVoidType() || !VR)
+ continue;
+
+ if (const RecordDecl *RRD = PT->getAsRecordDecl())
+ if (Optional<RegionVector> Out =
+ findRegionOfInterestInRecord(RRD, State, VR, VecF, depth + 1))
+ return Out;
+ }
- StringRef Sep;
- for (const MemRegion *R : RegionSequence) {
+ return None;
+}
- // Just keep going up to the base region.
- // Element regions may appear due to casts.
- if (isa<CXXBaseObjectRegion>(R) || isa<CXXTempObjectRegion>(R))
- continue;
-
- if (Sep.empty())
- Sep = prettyPrintFirstElement(FirstElement,
- /*MoreItemsExpected=*/true,
- IndirectionLevel, os);
-
- os << Sep;
-
- // Can only reasonably pretty-print DeclRegions.
- if (!isa<DeclRegion>(R))
- return false;
-
- const auto *DR = cast<DeclRegion>(R);
- Sep = DR->getValueType()->isAnyPointerType() ? "->" : ".";
- DR->getDecl()->getDeclName().print(os, PP);
+std::shared_ptr<PathDiagnosticPiece>
+NoStoreFuncVisitor::VisitNode(const ExplodedNode *N, BugReporterContext &BR,
+ BugReport &R) {
+
+ const LocationContext *Ctx = N->getLocationContext();
+ const StackFrameContext *SCtx = Ctx->getStackFrame();
+ ProgramStateRef State = N->getState();
+ auto CallExitLoc = N->getLocationAs<CallExitBegin>();
+
+ // No diagnostic if region was modified inside the frame.
+ if (!CallExitLoc || isRegionOfInterestModifiedInFrame(N))
+ return nullptr;
+
+ CallEventRef<> Call =
+ BR.getStateManager().getCallEventManager().getCaller(SCtx, State);
+
+ // Region of interest corresponds to an IVar, exiting a method
+ // which could have written into that IVar, but did not.
+ if (const auto *MC = dyn_cast<ObjCMethodCall>(Call)) {
+ if (const auto *IvarR = dyn_cast<ObjCIvarRegion>(RegionOfInterest)) {
+ const MemRegion *SelfRegion = MC->getReceiverSVal().getAsRegion();
+ if (RegionOfInterest->isSubRegionOf(SelfRegion) &&
+ potentiallyWritesIntoIvar(Call->getRuntimeDefinition().getDecl(),
+ IvarR->getDecl()))
+ return maybeEmitNote(R, *Call, N, {}, SelfRegion, "self",
+ /*FirstIsReferenceType=*/false, 1);
}
+ }
- if (Sep.empty())
- prettyPrintFirstElement(FirstElement,
- /*MoreItemsExpected=*/false, IndirectionLevel,
- os);
- return true;
+ if (const auto *CCall = dyn_cast<CXXConstructorCall>(Call)) {
+ const MemRegion *ThisR = CCall->getCXXThisVal().getAsRegion();
+ if (RegionOfInterest->isSubRegionOf(ThisR) &&
+ !CCall->getDecl()->isImplicit())
+ return maybeEmitNote(R, *Call, N, {}, ThisR, "this",
+ /*FirstIsReferenceType=*/false, 1);
+
+ // Do not generate diagnostics for not modified parameters in
+ // constructors.
+ return nullptr;
}
- /// Print first item in the chain, return new separator.
- StringRef prettyPrintFirstElement(StringRef FirstElement,
- bool MoreItemsExpected,
- int IndirectionLevel,
- llvm::raw_svector_ostream &os) {
- StringRef Out = ".";
-
- if (IndirectionLevel > 0 && MoreItemsExpected) {
- IndirectionLevel--;
- Out = "->";
+ ArrayRef<ParmVarDecl *> parameters = getCallParameters(Call);
+ for (unsigned I = 0; I < Call->getNumArgs() && I < parameters.size(); ++I) {
+ const ParmVarDecl *PVD = parameters[I];
+ SVal V = Call->getArgSVal(I);
+ bool ParamIsReferenceType = PVD->getType()->isReferenceType();
+ std::string ParamName = PVD->getNameAsString();
+
+ int IndirectionLevel = 1;
+ QualType T = PVD->getType();
+ while (const MemRegion *MR = V.getAsRegion()) {
+ if (RegionOfInterest->isSubRegionOf(MR) && !isPointerToConst(T))
+ return maybeEmitNote(R, *Call, N, {}, MR, ParamName,
+ ParamIsReferenceType, IndirectionLevel);
+
+ QualType PT = T->getPointeeType();
+ if (PT.isNull() || PT->isVoidType())
+ break;
+
+ if (const RecordDecl *RD = PT->getAsRecordDecl())
+ if (Optional<RegionVector> P =
+ findRegionOfInterestInRecord(RD, State, MR))
+ return maybeEmitNote(R, *Call, N, *P, RegionOfInterest, ParamName,
+ ParamIsReferenceType, IndirectionLevel);
+
+ V = State->getSVal(MR, PT);
+ T = PT;
+ IndirectionLevel++;
+ }
+ }
+
+ return nullptr;
+}
+
+void NoStoreFuncVisitor::findModifyingFrames(const ExplodedNode *N) {
+ assert(N->getLocationAs<CallExitBegin>());
+ ProgramStateRef LastReturnState = N->getState();
+ SVal ValueAtReturn = LastReturnState->getSVal(RegionOfInterest);
+ const LocationContext *Ctx = N->getLocationContext();
+ const StackFrameContext *OriginalSCtx = Ctx->getStackFrame();
+
+ do {
+ ProgramStateRef State = N->getState();
+ auto CallExitLoc = N->getLocationAs<CallExitBegin>();
+ if (CallExitLoc) {
+ LastReturnState = State;
+ ValueAtReturn = LastReturnState->getSVal(RegionOfInterest);
}
- if (IndirectionLevel > 0 && MoreItemsExpected)
- os << "(";
+ FramesModifyingCalculated.insert(N->getLocationContext()->getStackFrame());
- for (int i=0; i<IndirectionLevel; i++)
- os << "*";
- os << FirstElement;
+ if (wasRegionOfInterestModifiedAt(RegionOfInterest, N, ValueAtReturn)) {
+ const StackFrameContext *SCtx = N->getStackFrame();
+ while (!SCtx->inTopFrame()) {
+ auto p = FramesModifyingRegion.insert(SCtx);
+ if (!p.second)
+ break; // Frame and all its parents already inserted.
+ SCtx = SCtx->getParent()->getStackFrame();
+ }
+ }
+
+ // Stop calculation at the call to the current function.
+ if (auto CE = N->getLocationAs<CallEnter>())
+ if (CE->getCalleeContext() == OriginalSCtx)
+ break;
- if (IndirectionLevel > 0 && MoreItemsExpected)
- os << ")";
+ N = N->getFirstPred();
+ } while (N);
+}
- return Out;
+std::shared_ptr<PathDiagnosticPiece> NoStoreFuncVisitor::maybeEmitNote(
+ BugReport &R, const CallEvent &Call, const ExplodedNode *N,
+ const RegionVector &FieldChain, const MemRegion *MatchedRegion,
+ StringRef FirstElement, bool FirstIsReferenceType,
+ unsigned IndirectionLevel) {
+ // Optimistically suppress uninitialized value bugs that result
+ // from system headers having a chance to initialize the value
+ // but failing to do so. It's too unlikely a system header's fault.
+ // It's much more likely a situation in which the function has a failure
+ // mode that the user decided not to check. If we want to hunt such
+ // omitted checks, we should provide an explicit function-specific note
+ // describing the precondition under which the function isn't supposed to
+ // initialize its out-parameter, and additionally check that such
+ // precondition can actually be fulfilled on the current path.
+ if (Call.isInSystemHeader()) {
+ // We make an exception for system header functions that have no branches.
+ // Such functions unconditionally fail to initialize the variable.
+ // If they call other functions that have more paths within them,
+ // this suppression would still apply when we visit these inner functions.
+ // One common example of a standard function that doesn't ever initialize
+ // its out parameter is operator placement new; it's up to the follow-up
+ // constructor (if any) to initialize the memory.
+ if (!N->getStackFrame()->getCFG()->isLinear())
+ R.markInvalid(getTag(), nullptr);
+ return nullptr;
}
-};
-} // end of anonymous namespace
+ PathDiagnosticLocation L =
+ PathDiagnosticLocation::create(N->getLocation(), SM);
+
+ // For now this shouldn't trigger, but once it does (as we add more
+ // functions to the body farm), we'll need to decide if these reports
+ // are worth suppressing as well.
+ if (!L.hasValidLocation())
+ return nullptr;
+
+ SmallString<256> sbuf;
+ llvm::raw_svector_ostream os(sbuf);
+ os << "Returning without writing to '";
+
+ // Do not generate the note if failed to pretty-print.
+ if (!prettyPrintRegionName(FirstElement, FirstIsReferenceType, MatchedRegion,
+ FieldChain, IndirectionLevel, os))
+ return nullptr;
+
+ os << "'";
+ return std::make_shared<PathDiagnosticEventPiece>(L, os.str());
+}
+
+bool NoStoreFuncVisitor::prettyPrintRegionName(StringRef FirstElement,
+ bool FirstIsReferenceType,
+ const MemRegion *MatchedRegion,
+ const RegionVector &FieldChain,
+ int IndirectionLevel,
+ llvm::raw_svector_ostream &os) {
+
+ if (FirstIsReferenceType)
+ IndirectionLevel--;
+
+ RegionVector RegionSequence;
+
+ // Add the regions in the reverse order, then reverse the resulting array.
+ assert(RegionOfInterest->isSubRegionOf(MatchedRegion));
+ const MemRegion *R = RegionOfInterest;
+ while (R != MatchedRegion) {
+ RegionSequence.push_back(R);
+ R = cast<SubRegion>(R)->getSuperRegion();
+ }
+ std::reverse(RegionSequence.begin(), RegionSequence.end());
+ RegionSequence.append(FieldChain.begin(), FieldChain.end());
+
+ StringRef Sep;
+ for (const MemRegion *R : RegionSequence) {
+
+ // Just keep going up to the base region.
+ // Element regions may appear due to casts.
+ if (isa<CXXBaseObjectRegion>(R) || isa<CXXTempObjectRegion>(R))
+ continue;
+
+ if (Sep.empty())
+ Sep = prettyPrintFirstElement(FirstElement,
+ /*MoreItemsExpected=*/true,
+ IndirectionLevel, os);
+
+ os << Sep;
+
+ // Can only reasonably pretty-print DeclRegions.
+ if (!isa<DeclRegion>(R))
+ return false;
+
+ const auto *DR = cast<DeclRegion>(R);
+ Sep = DR->getValueType()->isAnyPointerType() ? "->" : ".";
+ DR->getDecl()->getDeclName().print(os, PP);
+ }
+
+ if (Sep.empty())
+ prettyPrintFirstElement(FirstElement,
+ /*MoreItemsExpected=*/false, IndirectionLevel, os);
+ return true;
+}
+
+StringRef NoStoreFuncVisitor::prettyPrintFirstElement(
+ StringRef FirstElement, bool MoreItemsExpected, int IndirectionLevel,
+ llvm::raw_svector_ostream &os) {
+ StringRef Out = ".";
+
+ if (IndirectionLevel > 0 && MoreItemsExpected) {
+ IndirectionLevel--;
+ Out = "->";
+ }
+
+ if (IndirectionLevel > 0 && MoreItemsExpected)
+ os << "(";
+
+ for (int i = 0; i < IndirectionLevel; i++)
+ os << "*";
+ os << FirstElement;
+
+ if (IndirectionLevel > 0 && MoreItemsExpected)
+ os << ")";
+
+ return Out;
+}
+
+//===----------------------------------------------------------------------===//
+// Implementation of MacroNullReturnSuppressionVisitor.
+//===----------------------------------------------------------------------===//
namespace {
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