[cfe-commits] [Patch] Thread-safety analysis: more refactoring
Richard Smith
richard at metafoo.co.uk
Fri Oct 21 10:56:33 PDT 2011
On Fri, October 21, 2011 18:37, Delesley Hutchins wrote:
> Updated patch enclosed, and found at:
>
> http://codereview.appspot.com/5293049/
Please capitalize the comment for BuildLockset::removeLocksFromSet, then feel
free to check in.
Thanks!
> On Thu, Oct 20, 2011 at 7:51 PM, Richard Smith <richard at metafoo.co.uk> wrote:
>> On Wed, October 19, 2011 23:58, Delesley Hutchins wrote:
>>> This patch performs two additional refactorings. The first refactors
>>> lockset removal into a separate function, to be consistent with lockset
>>> addition. The second refactors the handling of invalid lock expressions
>>> into a separate routine, in preparation for better handling of such
>>> messages in more complex cases, such as attributes on destructors. There
>>> is no major change in functionality.
>>>
>>> http://codereview.appspot.com/5293049/
>>>
>>
>> Some comments below.
>>
>>
>> --- a/lib/Analysis/ThreadSafety.cpp
>> +++ b/lib/Analysis/ThreadSafety.cpp
>> @@ -161,6 +161,11 @@ class MutexID {
>> /// Recursive function that bottoms out when the final DeclRefExpr is
>> reached. void buildMutexID(Expr *Exp, Expr *Parent, int NumArgs,
>> const NamedDecl **FunArgDecls, Expr **FunArgs) {
>> + if (!Exp) {
>> + DeclSeq.clear();
>> + return;
>> + }
>>
>>
>> Can this happen? If this is a crash fix, there should be a testcase,
>> otherwise this should be an assert.
>>
>> +
>> if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Exp)) {
>> if (FunArgDecls) {
>> // Substitute call arguments for references to function parameters
>> @@ -202,11 +207,13 @@ class MutexID {
>> Expr **FunArgs = 0;
>> SmallVector<const NamedDecl*, 8> FunArgDecls;
>>
>>
>> + // If we are processing a raw attribute expression...
>> if (DeclExp == 0) {
>> buildMutexID(MutexExp, 0, 0, 0, 0);
>> return;
>> }
>>
>>
>> + // Get Parent and FunArgs from DeclExp
>>
>>
>> It'd be nice if this comment explained why we're doing this. As an outsider
>> to this code, it wasn't immediately obvious to me that we want to extract
>> these for substitution.
>>
>> if (MemberExpr *ME = dyn_cast<MemberExpr>(DeclExp)) {
>> Parent = ME->getBase();
>> } else if (CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(DeclExp))
>> {
>> @@ -250,6 +257,18 @@ public:
>> return !DeclSeq.empty();
>> }
>>
>>
>> + /// Issue a warning about an invalid lock expression
>> + static void warnInvalidLock(ThreadSafetyHandler &Handler, Expr* MutexExp,
>> + Expr *DeclExp, const NamedDecl* D) {
>> + SourceLocation Loc;
>> + if (DeclExp)
>> + Loc = DeclExp->getExprLoc();
>> +
>> + // FIXME: add a note about the attribute location in MutexExp or D
>> + if (Loc.isValid())
>> + Handler.handleInvalidLockExp(Loc);
>> + }
>> +
>> bool operator==(const MutexID &other) const {
>> return DeclSeq == other.DeclSeq;
>> }
>> @@ -329,6 +348,8 @@ typedef llvm::ImmutableMap<MutexID, LockData> Lockset;
>> /// output error messages related to missing locks.
>> /// FIXME: In future, we may be able to not inherit from a visitor.
>> class BuildLockset : public StmtVisitor<BuildLockset> {
>> + friend class ThreadSafetyAnalyzer;
>> +
>> ThreadSafetyHandler &Handler;
>> Lockset LSet;
>> Lockset::Factory &LocksetFactory;
>> @@ -339,6 +360,8 @@ class BuildLockset : public StmtVisitor<BuildLockset> {
>>
>>
>> template <class AttrType>
>> void addLocksToSet(LockKind LK, AttrType *Attr, Expr *Exp, NamedDecl *D);
>> + void removeLocksFromSet(UnlockFunctionAttr *Attr,
>> + Expr *Exp, NamedDecl* FunDecl);
>>
>>
>> const ValueDecl *getValueDecl(Expr *Exp);
>> void warnIfMutexNotHeld (const NamedDecl *D, Expr *Exp, AccessKind AK,
>> @@ -401,9 +424,10 @@ void BuildLockset::addLock(SourceLocation LockLoc,
>> MutexID &Mutex,
>> LockData NewLock(LockLoc, LK);
>>
>>
>> // FIXME: Don't always warn when we have support for reentrant locks.
>> - if (locksetContains(Mutex))
>> + if (locksetContains(Mutex) && LockLoc.isValid())
>>
>>
>> What's the meaning of an invalid LockLoc? A test or an assert would
>> elucidate.
>>
>> Handler.handleDoubleLock(Mutex.getName(), LockLoc);
>> - LSet = LocksetFactory.add(LSet, Mutex, NewLock);
>> + else
>> + LSet = LocksetFactory.add(LSet, Mutex, NewLock);
>> }
>>
>>
>> /// \brief Remove a lock from the lockset, warning if the lock is not
>> there. @@ -411,10 +435,10 @@ void BuildLockset::addLock(SourceLocation
>> LockLoc,
>> MutexID &Mutex,
>> /// \param UnlockLoc The source location of the unlock (only used in error
>> msg) void BuildLockset::removeLock(SourceLocation UnlockLoc, MutexID
>> &Mutex) {
>> Lockset NewLSet = LocksetFactory.remove(LSet, Mutex);
>> - if(NewLSet == LSet)
>> + if(NewLSet == LSet && UnlockLoc.isValid())
>> Handler.handleUnmatchedUnlock(Mutex.getName(), UnlockLoc);
>> -
>> - LSet = NewLSet;
>> + else
>> + LSet = NewLSet;
>> }
>>
>>
>> /// \brief This function, parameterized by an attribute type, is used to
>> add a @@ -428,10 +452,9 @@ void BuildLockset::addLocksToSet(LockKind LK,
>> AttrType
>> *Attr,
>>
>>
>> if (Attr->args_size() == 0) {
>> // The mutex held is the "this" object.
>> -
>> MutexID Mutex(0, Exp, FunDecl);
>> if (!Mutex.isValid())
>> - Handler.handleInvalidLockExp(Exp->getExprLoc());
>> + MutexID::warnInvalidLock(Handler, 0, Exp, FunDecl);
>> else
>> addLock(ExpLocation, Mutex, LK);
>> return;
>> @@ -440,12 +463,39 @@ void BuildLockset::addLocksToSet(LockKind LK, AttrType
>> *Attr,
>> for (iterator_type I=Attr->args_begin(), E=Attr->args_end(); I != E; ++I)
>> {
>> MutexID Mutex(*I, Exp, FunDecl);
>> if (!Mutex.isValid())
>> - Handler.handleInvalidLockExp(Exp->getExprLoc());
>> + MutexID::warnInvalidLock(Handler, *I, Exp, FunDecl);
>> else
>> addLock(ExpLocation, Mutex, LK);
>> }
>> }
>>
>>
>> +/// \brief this function adds a set of locks specified as attribute
>> arguments +/// to the lockset.
>>
>>
>> This comment needs updating.
>>
>>
>> +void BuildLockset::removeLocksFromSet(UnlockFunctionAttr *Attr,
>> + Expr *Exp, NamedDecl* FunDecl) {
>> + SourceLocation ExpLocation;
>> + if (Exp) ExpLocation = Exp->getExprLoc();
>> +
>> + if (Attr->args_size() == 0) {
>> + // The mutex held is the "this" object.
>> + MutexID Mu(0, Exp, FunDecl);
>> + if (!Mu.isValid())
>> + MutexID::warnInvalidLock(Handler, 0, Exp, FunDecl);
>> + else
>> + removeLock(ExpLocation, Mu);
>> + return;
>> + }
>> +
>> + for (UnlockFunctionAttr::args_iterator I = Attr->args_begin(),
>> + E = Attr->args_end(); I != E; ++I) {
>> + MutexID Mutex(*I, Exp, FunDecl);
>> + if (!Mutex.isValid())
>> + MutexID::warnInvalidLock(Handler, *I, Exp, FunDecl);
>> + else
>> + removeLock(ExpLocation, Mutex);
>> + }
>> +}
>> +
>> /// \brief Gets the value decl pointer from DeclRefExprs or MemberExprs
>> const ValueDecl *BuildLockset::getValueDecl(Expr *Exp) {
>> if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Exp))
>> @@ -466,7 +516,7 @@ void BuildLockset::warnIfMutexNotHeld(const NamedDecl
>> *D,
>> Expr *Exp,
>>
>>
>> MutexID Mutex(MutexExp, Exp, D);
>> if (!Mutex.isValid())
>> - Handler.handleInvalidLockExp(MutexExp->getExprLoc());
>> + MutexID::warnInvalidLock(Handler, MutexExp, Exp, D);
>> else if (!locksetContainsAtLeast(Mutex, LK))
>> Handler.handleMutexNotHeld(D, POK, Mutex.getName(), LK,
>> Exp->getExprLoc());
>> }
>> @@ -529,8 +579,6 @@ void BuildLockset::checkAccess(Expr *Exp, AccessKind AK)
>> {
>> /// FIXME: Do not flag an error for member variables accessed in
>> constructors/ /// destructors
>> void BuildLockset::handleCall(Expr *Exp, NamedDecl *D) {
>> - SourceLocation ExpLocation = Exp->getExprLoc();
>> -
>> AttrVec &ArgAttrs = D->getAttrs();
>> for(unsigned i = 0; i < ArgAttrs.size(); ++i) {
>> Attr *Attr = ArgAttrs[i];
>> @@ -555,24 +603,7 @@ void BuildLockset::handleCall(Expr *Exp, NamedDecl *D)
>> {
>> // mutexes from the lockset, and flag a warning if they are not there.
>> case attr::UnlockFunction: {
>> UnlockFunctionAttr *UFAttr = cast<UnlockFunctionAttr>(Attr);
>> -
>> - if (UFAttr->args_size() == 0) { // The lock held is the "this"
>> object. - MutexID Mu(0, Exp, D);
>> - if (!Mu.isValid())
>> - Handler.handleInvalidLockExp(Exp->getExprLoc());
>> - else
>> - removeLock(ExpLocation, Mu);
>> - break;
>> - }
>> -
>> - for (UnlockFunctionAttr::args_iterator I = UFAttr->args_begin(),
>> - E = UFAttr->args_end(); I != E; ++I) {
>> - MutexID Mutex(*I, Exp, D);
>> - if (!Mutex.isValid())
>> - Handler.handleInvalidLockExp(Exp->getExprLoc());
>> - else
>> - removeLock(ExpLocation, Mutex);
>> - }
>> + removeLocksFromSet(UFAttr, Exp, D);
>> break;
>> }
>>
>>
>> @@ -601,10 +632,10 @@ void BuildLockset::handleCall(Expr *Exp, NamedDecl
>> *D) {
>> E = LEAttr->args_end(); I != E; ++I) {
>> MutexID Mutex(*I, Exp, D);
>> if (!Mutex.isValid())
>> - Handler.handleInvalidLockExp((*I)->getExprLoc());
>> + MutexID::warnInvalidLock(Handler, *I, Exp, D);
>> else if (locksetContains(Mutex))
>> Handler.handleFunExcludesLock(D->getName(), Mutex.getName(),
>> - ExpLocation);
>> + Exp->getExprLoc());
>> }
>> break;
>> }
>> @@ -737,7 +768,7 @@ Lockset ThreadSafetyAnalyzer::addLock(Lockset &LSet,
>> Expr
>> *MutexExp,
>> LockKind LK, SourceLocation Loc) {
>> MutexID Mutex(MutexExp, 0, D);
>> if (!Mutex.isValid()) {
>> - Handler.handleInvalidLockExp(MutexExp->getExprLoc());
>> + MutexID::warnInvalidLock(Handler, MutexExp, 0, D);
>> return LSet;
>> }
>> LockData NewLock(Loc, LK);
>>
>>
>>
>>
>
>
>
> --
> DeLesley Hutchins | Software Engineer | delesley at google.com | 505-206-0315
>
>
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