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Thread Safety Analysis: refactor to make more methods accept const pointers, 

adjust checkAccess.  No change in functionality.

llvm-svn: 169348
This commit is contained in:
DeLesley Hutchins 2012-12-05 00:52:33 +00:00
parent bfc3ef55be
commit 5df82f2155
1 changed files with 97 additions and 89 deletions
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186
clang/lib/Analysis/ThreadSafety.cpp
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@ -165,15 +165,16 @@ private:
/// should be evaluated; multiple calling contexts can be chained together
/// by the lock_returned attribute.
struct CallingContext {
const NamedDecl* AttrDecl; // The decl to which the attribute is attached.
Expr* SelfArg; // Implicit object argument -- e.g. 'this'
bool SelfArrow; // is Self referred to with -> or .?
unsigned NumArgs; // Number of funArgs
Expr** FunArgs; // Function arguments
CallingContext* PrevCtx; // The previous context; or 0 if none.
const NamedDecl* AttrDecl; // The decl to which the attribute is attached.
const Expr* SelfArg; // Implicit object argument -- e.g. 'this'
bool SelfArrow; // is Self referred to with -> or .?
unsigned NumArgs; // Number of funArgs
const Expr* const* FunArgs; // Function arguments
CallingContext* PrevCtx; // The previous context; or 0 if none.
CallingContext(const NamedDecl *D = 0, Expr *S = 0,
unsigned N = 0, Expr **A = 0, CallingContext *P = 0)
CallingContext(const NamedDecl *D = 0, const Expr *S = 0,
unsigned N = 0, const Expr* const *A = 0,
CallingContext *P = 0)
: AttrDecl(D), SelfArg(S), SelfArrow(false),
NumArgs(N), FunArgs(A), PrevCtx(P)
{ }
@ -273,15 +274,16 @@ private:
/// NDeref returns the number of Derefence and AddressOf operations
/// preceeding the Expr; this is used to decide whether to pretty-print
/// SExprs with . or ->.
unsigned buildSExpr(Expr *Exp, CallingContext* CallCtx, int* NDeref = 0) {
unsigned buildSExpr(const Expr *Exp, CallingContext* CallCtx,
int* NDeref = 0) {
if (!Exp)
return 0;
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Exp)) {
NamedDecl *ND = cast<NamedDecl>(DRE->getDecl()->getCanonicalDecl());
ParmVarDecl *PV = dyn_cast_or_null<ParmVarDecl>(ND);
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Exp)) {
const NamedDecl *ND = cast<NamedDecl>(DRE->getDecl()->getCanonicalDecl());
const ParmVarDecl *PV = dyn_cast_or_null<ParmVarDecl>(ND);
if (PV) {
FunctionDecl *FD =
const FunctionDecl *FD =
cast<FunctionDecl>(PV->getDeclContext())->getCanonicalDecl();
unsigned i = PV->getFunctionScopeIndex();
@ -310,18 +312,18 @@ private:
makeThis();
return 1;
}
} else if (MemberExpr *ME = dyn_cast<MemberExpr>(Exp)) {
NamedDecl *ND = ME->getMemberDecl();
} else if (const MemberExpr *ME = dyn_cast<MemberExpr>(Exp)) {
const NamedDecl *ND = ME->getMemberDecl();
int ImplicitDeref = ME->isArrow() ? 1 : 0;
unsigned Root = makeDot(ND, false);
unsigned Sz = buildSExpr(ME->getBase(), CallCtx, &ImplicitDeref);
NodeVec[Root].setArrow(ImplicitDeref > 0);
NodeVec[Root].setSize(Sz + 1);
return Sz + 1;
} else if (CXXMemberCallExpr *CMCE = dyn_cast<CXXMemberCallExpr>(Exp)) {
} else if (const CXXMemberCallExpr *CMCE = dyn_cast<CXXMemberCallExpr>(Exp)) {
// When calling a function with a lock_returned attribute, replace
// the function call with the expression in lock_returned.
CXXMethodDecl* MD =
const CXXMethodDecl* MD =
cast<CXXMethodDecl>(CMCE->getMethodDecl()->getMostRecentDecl());
if (LockReturnedAttr* At = MD->getAttr<LockReturnedAttr>()) {
CallingContext LRCallCtx(CMCE->getMethodDecl());
@ -344,14 +346,14 @@ private:
unsigned NumCallArgs = CMCE->getNumArgs();
unsigned Root = makeMCall(NumCallArgs, CMCE->getMethodDecl());
unsigned Sz = buildSExpr(CMCE->getImplicitObjectArgument(), CallCtx);
Expr** CallArgs = CMCE->getArgs();
const Expr* const* CallArgs = CMCE->getArgs();
for (unsigned i = 0; i < NumCallArgs; ++i) {
Sz += buildSExpr(CallArgs[i], CallCtx);
}
NodeVec[Root].setSize(Sz + 1);
return Sz + 1;
} else if (CallExpr *CE = dyn_cast<CallExpr>(Exp)) {
FunctionDecl* FD =
} else if (const CallExpr *CE = dyn_cast<CallExpr>(Exp)) {
const FunctionDecl* FD =
cast<FunctionDecl>(CE->getDirectCallee()->getMostRecentDecl());
if (LockReturnedAttr* At = FD->getAttr<LockReturnedAttr>()) {
CallingContext LRCallCtx(CE->getDirectCallee());
@ -362,7 +364,7 @@ private:
}
// Treat smart pointers and iterators as pointers;
// ignore the * and -> operators.
if (CXXOperatorCallExpr *OE = dyn_cast<CXXOperatorCallExpr>(CE)) {
if (const CXXOperatorCallExpr *OE = dyn_cast<CXXOperatorCallExpr>(CE)) {
OverloadedOperatorKind k = OE->getOperator();
if (k == OO_Star) {
if (NDeref) ++(*NDeref);
@ -375,19 +377,19 @@ private:
unsigned NumCallArgs = CE->getNumArgs();
unsigned Root = makeCall(NumCallArgs, 0);
unsigned Sz = buildSExpr(CE->getCallee(), CallCtx);
Expr** CallArgs = CE->getArgs();
const Expr* const* CallArgs = CE->getArgs();
for (unsigned i = 0; i < NumCallArgs; ++i) {
Sz += buildSExpr(CallArgs[i], CallCtx);
}
NodeVec[Root].setSize(Sz+1);
return Sz+1;
} else if (BinaryOperator *BOE = dyn_cast<BinaryOperator>(Exp)) {
} else if (const BinaryOperator *BOE = dyn_cast<BinaryOperator>(Exp)) {
unsigned Root = makeBinary();
unsigned Sz = buildSExpr(BOE->getLHS(), CallCtx);
Sz += buildSExpr(BOE->getRHS(), CallCtx);
NodeVec[Root].setSize(Sz);
return Sz;
} else if (UnaryOperator *UOE = dyn_cast<UnaryOperator>(Exp)) {
} else if (const UnaryOperator *UOE = dyn_cast<UnaryOperator>(Exp)) {
// Ignore & and * operators -- they're no-ops.
// However, we try to figure out whether the expression is a pointer,
// so we can use . and -> appropriately in error messages.
@ -413,13 +415,14 @@ private:
unsigned Sz = buildSExpr(UOE->getSubExpr(), CallCtx);
NodeVec[Root].setSize(Sz);
return Sz;
} else if (ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(Exp)) {
} else if (const ArraySubscriptExpr *ASE =
dyn_cast<ArraySubscriptExpr>(Exp)) {
unsigned Root = makeIndex();
unsigned Sz = buildSExpr(ASE->getBase(), CallCtx);
Sz += buildSExpr(ASE->getIdx(), CallCtx);
NodeVec[Root].setSize(Sz);
return Sz;
} else if (AbstractConditionalOperator *CE =
} else if (const AbstractConditionalOperator *CE =
dyn_cast<AbstractConditionalOperator>(Exp)) {
unsigned Root = makeUnknown(3);
unsigned Sz = buildSExpr(CE->getCond(), CallCtx);
@ -427,20 +430,20 @@ private:
Sz += buildSExpr(CE->getFalseExpr(), CallCtx);
NodeVec[Root].setSize(Sz);
return Sz;
} else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(Exp)) {
} else if (const ChooseExpr *CE = dyn_cast<ChooseExpr>(Exp)) {
unsigned Root = makeUnknown(3);
unsigned Sz = buildSExpr(CE->getCond(), CallCtx);
Sz += buildSExpr(CE->getLHS(), CallCtx);
Sz += buildSExpr(CE->getRHS(), CallCtx);
NodeVec[Root].setSize(Sz);
return Sz;
} else if (CastExpr *CE = dyn_cast<CastExpr>(Exp)) {
} else if (const CastExpr *CE = dyn_cast<CastExpr>(Exp)) {
return buildSExpr(CE->getSubExpr(), CallCtx, NDeref);
} else if (ParenExpr *PE = dyn_cast<ParenExpr>(Exp)) {
} else if (const ParenExpr *PE = dyn_cast<ParenExpr>(Exp)) {
return buildSExpr(PE->getSubExpr(), CallCtx, NDeref);
} else if (ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Exp)) {
} else if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Exp)) {
return buildSExpr(EWC->getSubExpr(), CallCtx, NDeref);
} else if (CXXBindTemporaryExpr *E = dyn_cast<CXXBindTemporaryExpr>(Exp)) {
} else if (const CXXBindTemporaryExpr *E = dyn_cast<CXXBindTemporaryExpr>(Exp)) {
return buildSExpr(E->getSubExpr(), CallCtx, NDeref);
} else if (isa<CharacterLiteral>(Exp) ||
isa<CXXNullPtrLiteralExpr>(Exp) ||
@ -464,12 +467,12 @@ private:
/// \param DeclExp An expression involving the Decl on which the attribute
/// occurs.
/// \param D The declaration to which the lock/unlock attribute is attached.
void buildSExprFromExpr(Expr *MutexExp, Expr *DeclExp, const NamedDecl *D,
VarDecl *SelfDecl = 0) {
void buildSExprFromExpr(const Expr *MutexExp, const Expr *DeclExp,
const NamedDecl *D, VarDecl *SelfDecl = 0) {
CallingContext CallCtx(D);
if (MutexExp) {
if (StringLiteral* SLit = dyn_cast<StringLiteral>(MutexExp)) {
if (const StringLiteral* SLit = dyn_cast<StringLiteral>(MutexExp)) {
if (SLit->getString() == StringRef("*"))
// The "*" expr is a universal lock, which essentially turns off
// checks until it is removed from the lockset.
@ -489,18 +492,21 @@ private:
// Examine DeclExp to find SelfArg and FunArgs, which are used to substitute
// for formal parameters when we call buildMutexID later.
if (MemberExpr *ME = dyn_cast<MemberExpr>(DeclExp)) {
if (const MemberExpr *ME = dyn_cast<MemberExpr>(DeclExp)) {
CallCtx.SelfArg = ME->getBase();
CallCtx.SelfArrow = ME->isArrow();
} else if (CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(DeclExp)) {
} else if (const CXXMemberCallExpr *CE =
dyn_cast<CXXMemberCallExpr>(DeclExp)) {
CallCtx.SelfArg = CE->getImplicitObjectArgument();
CallCtx.SelfArrow = dyn_cast<MemberExpr>(CE->getCallee())->isArrow();
CallCtx.NumArgs = CE->getNumArgs();
CallCtx.FunArgs = CE->getArgs();
} else if (CallExpr *CE = dyn_cast<CallExpr>(DeclExp)) {
} else if (const CallExpr *CE =
dyn_cast<CallExpr>(DeclExp)) {
CallCtx.NumArgs = CE->getNumArgs();
CallCtx.FunArgs = CE->getArgs();
} else if (CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(DeclExp)) {
} else if (const CXXConstructExpr *CE =
dyn_cast<CXXConstructExpr>(DeclExp)) {
CallCtx.SelfArg = 0; // Will be set below
CallCtx.NumArgs = CE->getNumArgs();
CallCtx.FunArgs = CE->getArgs();
@ -544,7 +550,7 @@ public:
/// occurs.
/// \param D The declaration to which the lock/unlock attribute is attached.
/// Caller must check isValid() after construction.
SExpr(Expr* MutexExp, Expr *DeclExp, const NamedDecl* D,
SExpr(const Expr* MutexExp, const Expr *DeclExp, const NamedDecl* D,
VarDecl *SelfDecl=0) {
buildSExprFromExpr(MutexExp, DeclExp, D, SelfDecl);
}
@ -567,8 +573,9 @@ public:
}
/// Issue a warning about an invalid lock expression
static void warnInvalidLock(ThreadSafetyHandler &Handler, Expr* MutexExp,
Expr *DeclExp, const NamedDecl* D) {
static void warnInvalidLock(ThreadSafetyHandler &Handler,
const Expr *MutexExp,
const Expr *DeclExp, const NamedDecl* D) {
SourceLocation Loc;
if (DeclExp)
Loc = DeclExp->getExprLoc();
@ -1734,14 +1741,15 @@ class BuildLockset : public StmtVisitor<BuildLockset> {
unsigned CtxIndex;
// Helper functions
const ValueDecl *getValueDecl(Expr *Exp);
const ValueDecl *getValueDecl(const Expr *Exp);
void warnIfMutexNotHeld(const NamedDecl *D, Expr *Exp, AccessKind AK,
void warnIfMutexNotHeld(const NamedDecl *D, const Expr *Exp, AccessKind AK,
Expr *MutexExp, ProtectedOperationKind POK);
void warnIfMutexHeld(const NamedDecl *D, Expr *Exp, Expr *MutexExp);
void warnIfMutexHeld(const NamedDecl *D, const Expr *Exp, Expr *MutexExp);
void checkAccess(const Expr *Exp, AccessKind AK);
void checkPtAccess(const Expr *Exp, AccessKind AK);
void checkAccess(Expr *Exp, AccessKind AK);
void checkDereference(Expr *Exp, AccessKind AK);
void handleCall(Expr *Exp, const NamedDecl *D, VarDecl *VD = 0);
public:
@ -1763,7 +1771,10 @@ public:
/// \brief Gets the value decl pointer from DeclRefExprs or MemberExprs
const ValueDecl *BuildLockset::getValueDecl(Expr *Exp) {
const ValueDecl *BuildLockset::getValueDecl(const Expr *Exp) {
if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(Exp))
return getValueDecl(CE->getSubExpr());
if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Exp))
return DR->getDecl();
@ -1775,7 +1786,7 @@ const ValueDecl *BuildLockset::getValueDecl(Expr *Exp) {
/// \brief Warn if the LSet does not contain a lock sufficient to protect access
/// of at least the passed in AccessKind.
void BuildLockset::warnIfMutexNotHeld(const NamedDecl *D, Expr *Exp,
void BuildLockset::warnIfMutexNotHeld(const NamedDecl *D, const Expr *Exp,
AccessKind AK, Expr *MutexExp,
ProtectedOperationKind POK) {
LockKind LK = getLockKindFromAccessKind(AK);
@ -1814,7 +1825,7 @@ void BuildLockset::warnIfMutexNotHeld(const NamedDecl *D, Expr *Exp,
}
/// \brief Warn if the LSet contains the given lock.
void BuildLockset::warnIfMutexHeld(const NamedDecl *D, Expr* Exp,
void BuildLockset::warnIfMutexHeld(const NamedDecl *D, const Expr* Exp,
Expr *MutexExp) {
SExpr Mutex(MutexExp, Exp, D);
if (!Mutex.isValid()) {
@ -1832,39 +1843,23 @@ void BuildLockset::warnIfMutexHeld(const NamedDecl *D, Expr* Exp,
}
/// \brief This method identifies variable dereferences and checks pt_guarded_by
/// and pt_guarded_var annotations. Note that we only check these annotations
/// at the time a pointer is dereferenced.
/// FIXME: We need to check for other types of pointer dereferences
/// (e.g. [], ->) and deal with them here.
/// \param Exp An expression that has been read or written.
void BuildLockset::checkDereference(Expr *Exp, AccessKind AK) {
UnaryOperator *UO = dyn_cast<UnaryOperator>(Exp);
if (!UO || UO->getOpcode() != clang::UO_Deref)
/// \brief Checks guarded_by and pt_guarded_by attributes.
/// Whenever we identify an access (read or write) to a DeclRefExpr that is
/// marked with guarded_by, we must ensure the appropriate mutexes are held.
/// Similarly, we check if the access is to an expression that dereferences
/// a pointer marked with pt_guarded_by.
void BuildLockset::checkAccess(const Expr *Exp, AccessKind AK) {
Exp = Exp->IgnoreParenCasts();
if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(Exp)) {
// For dereferences
if (UO->getOpcode() == clang::UO_Deref)
checkPtAccess(UO->getSubExpr(), AK);
return;
Exp = UO->getSubExpr()->IgnoreParenCasts();
}
const ValueDecl *D = getValueDecl(Exp);
if(!D || !D->hasAttrs())
return;
if (D->getAttr<PtGuardedVarAttr>() && FSet.isEmpty())
Analyzer->Handler.handleNoMutexHeld(D, POK_VarDereference, AK,
Exp->getExprLoc());
const AttrVec &ArgAttrs = D->getAttrs();
for(unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i)
if (PtGuardedByAttr *PGBAttr = dyn_cast<PtGuardedByAttr>(ArgAttrs[i]))
warnIfMutexNotHeld(D, Exp, AK, PGBAttr->getArg(), POK_VarDereference);
}
/// \brief Checks guarded_by and guarded_var attributes.
/// Whenever we identify an access (read or write) of a DeclRefExpr or
/// MemberExpr, we need to check whether there are any guarded_by or
/// guarded_var attributes, and make sure we hold the appropriate mutexes.
void BuildLockset::checkAccess(Expr *Exp, AccessKind AK) {
const ValueDecl *D = getValueDecl(Exp);
if(!D || !D->hasAttrs())
if (!D || !D->hasAttrs())
return;
if (D->getAttr<GuardedVarAttr>() && FSet.isEmpty())
@ -1872,11 +1867,30 @@ void BuildLockset::checkAccess(Expr *Exp, AccessKind AK) {
Exp->getExprLoc());
const AttrVec &ArgAttrs = D->getAttrs();
for(unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i)
for (unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i)
if (GuardedByAttr *GBAttr = dyn_cast<GuardedByAttr>(ArgAttrs[i]))
warnIfMutexNotHeld(D, Exp, AK, GBAttr->getArg(), POK_VarAccess);
}
/// \brief Checks pt_guarded_by and pt_guarded_var attributes.
void BuildLockset::checkPtAccess(const Expr *Exp, AccessKind AK) {
Exp = Exp->IgnoreParenCasts();
const ValueDecl *D = getValueDecl(Exp);
if (!D || !D->hasAttrs())
return;
if (D->getAttr<PtGuardedVarAttr>() && FSet.isEmpty())
Analyzer->Handler.handleNoMutexHeld(D, POK_VarDereference, AK,
Exp->getExprLoc());
const AttrVec &ArgAttrs = D->getAttrs();
for (unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i)
if (PtGuardedByAttr *GBAttr = dyn_cast<PtGuardedByAttr>(ArgAttrs[i]))
warnIfMutexNotHeld(D, Exp, AK, GBAttr->getArg(), POK_VarDereference);
}
/// \brief Process a function call, method call, constructor call,
/// or destructor call. This involves looking at the attributes on the
/// corresponding function/method/constructor/destructor, issuing warnings,
@ -2010,9 +2024,7 @@ void BuildLockset::VisitUnaryOperator(UnaryOperator *UO) {
case clang::UO_PostInc:
case clang::UO_PreDec:
case clang::UO_PreInc: {
Expr *SubExp = UO->getSubExpr()->IgnoreParenCasts();
checkAccess(SubExp, AK_Written);
checkDereference(SubExp, AK_Written);
checkAccess(UO->getSubExpr(), AK_Written);
break;
}
default:
@ -2030,9 +2042,7 @@ void BuildLockset::VisitBinaryOperator(BinaryOperator *BO) {
// adjust the context
LVarCtx = Analyzer->LocalVarMap.getNextContext(CtxIndex, BO, LVarCtx);
Expr *LHSExp = BO->getLHS()->IgnoreParenCasts();
checkAccess(LHSExp, AK_Written);
checkDereference(LHSExp, AK_Written);
checkAccess(BO->getLHS(), AK_Written);
}
/// Whenever we do an LValue to Rvalue cast, we are reading a variable and
@ -2041,9 +2051,7 @@ void BuildLockset::VisitBinaryOperator(BinaryOperator *BO) {
void BuildLockset::VisitCastExpr(CastExpr *CE) {
if (CE->getCastKind() != CK_LValueToRValue)
return;
Expr *SubExp = CE->getSubExpr()->IgnoreParenCasts();
checkAccess(SubExp, AK_Read);
checkDereference(SubExp, AK_Read);
checkAccess(CE->getSubExpr(), AK_Read);
}