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llvm-project/clang/lib/Analysis/Consumed.cpp
Chris Wailes 93edffa8fe Fixed bug with checking the kind of types. 
The isLValueReferenceType function checks to see if the QualType's
canonical type is an LValue reference, and not if the QualType
itself is an LValue reference.  This caused a segfault when trying
to cast the QualType's Type to a LValueReference.  This is now
fixed by casting the result of getCanonicalType().

In addition, a test was added to isConsumableType to prevent
segfaults when a type being tested by the analysis is a reference
to a pointer or a pointer to a reference.

llvm-svn: 193751
2013-10-31 15:38:12 +00:00

1484 lines
44 KiB
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//===- Consumed.cpp --------------------------------------------*- C++ --*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// A intra-procedural analysis for checking consumed properties. This is based,
// in part, on research on linear types.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/Type.h"
#include "clang/Analysis/Analyses/PostOrderCFGView.h"
#include "clang/Analysis/AnalysisContext.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/Analyses/Consumed.h"
#include "clang/Basic/OperatorKinds.h"
#include "clang/Basic/SourceLocation.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/raw_ostream.h"
// TODO: Use information from tests in while-loop conditional.
// TODO: Add notes about the actual and expected state for
// TODO: Correctly identify unreachable blocks when chaining boolean operators.
// TODO: Adjust the parser and AttributesList class to support lists of
// identifiers.
// TODO: Warn about unreachable code.
// TODO: Switch to using a bitmap to track unreachable blocks.
// TODO: Handle variable definitions, e.g. bool valid = x.isValid();
// if (valid) ...; (Deferred)
// TODO: Take notes on state transitions to provide better warning messages.
// (Deferred)
// TODO: Test nested conditionals: A) Checking the same value multiple times,
// and 2) Checking different values. (Deferred)
using namespace clang;
using namespace consumed;
// Key method definition
ConsumedWarningsHandlerBase::~ConsumedWarningsHandlerBase() {}
static SourceLocation getFirstStmtLoc(const CFGBlock *Block) {
// Find the source location of the first statement in the block, if the block
// is not empty.
for (CFGBlock::const_iterator BI = Block->begin(), BE = Block->end();
BI != BE; ++BI) {
if (Optional<CFGStmt> CS = BI->getAs<CFGStmt>())
return CS->getStmt()->getLocStart();
}
// Block is empty.
// If we have one successor, return the first statement in that block
if (Block->succ_size() == 1 && *Block->succ_begin())
return getFirstStmtLoc(*Block->succ_begin());
return SourceLocation();
}
static SourceLocation getLastStmtLoc(const CFGBlock *Block) {
// Find the source location of the last statement in the block, if the block
// is not empty.
if (const Stmt *StmtNode = Block->getTerminator()) {
return StmtNode->getLocStart();
} else {
for (CFGBlock::const_reverse_iterator BI = Block->rbegin(),
BE = Block->rend(); BI != BE; ++BI) {
if (Optional<CFGStmt> CS = BI->getAs<CFGStmt>())
return CS->getStmt()->getLocStart();
}
}
// If we have one successor, return the first statement in that block
SourceLocation Loc;
if (Block->succ_size() == 1 && *Block->succ_begin())
Loc = getFirstStmtLoc(*Block->succ_begin());
if (Loc.isValid())
return Loc;
// If we have one predecessor, return the last statement in that block
if (Block->pred_size() == 1 && *Block->pred_begin())
return getLastStmtLoc(*Block->pred_begin());
return Loc;
}
static ConsumedState invertConsumedUnconsumed(ConsumedState State) {
switch (State) {
case CS_Unconsumed:
return CS_Consumed;
case CS_Consumed:
return CS_Unconsumed;
case CS_None:
return CS_None;
case CS_Unknown:
return CS_Unknown;
}
llvm_unreachable("invalid enum");
}
static bool isCallableInState(const CallableWhenAttr *CWAttr,
ConsumedState State) {
CallableWhenAttr::callableState_iterator I = CWAttr->callableState_begin(),
E = CWAttr->callableState_end();
for (; I != E; ++I) {
ConsumedState MappedAttrState = CS_None;
switch (*I) {
case CallableWhenAttr::Unknown:
MappedAttrState = CS_Unknown;
break;
case CallableWhenAttr::Unconsumed:
MappedAttrState = CS_Unconsumed;
break;
case CallableWhenAttr::Consumed:
MappedAttrState = CS_Consumed;
break;
}
if (MappedAttrState == State)
return true;
}
return false;
}
static bool isConsumableType(const QualType &QT) {
if (QT->isPointerType() || QT->isReferenceType())
return false;
if (const CXXRecordDecl *RD = QT->getAsCXXRecordDecl())
return RD->hasAttr<ConsumableAttr>();
return false;
}
static bool isKnownState(ConsumedState State) {
switch (State) {
case CS_Unconsumed:
case CS_Consumed:
return true;
case CS_None:
case CS_Unknown:
return false;
}
llvm_unreachable("invalid enum");
}
static bool isRValueRefish(QualType ParamType) {
return ParamType->isRValueReferenceType() ||
(ParamType->isLValueReferenceType() &&
!cast<LValueReferenceType>(
ParamType.getCanonicalType())->isSpelledAsLValue());
}
static bool isTestingFunction(const FunctionDecl *FunDecl) {
return FunDecl->hasAttr<TestTypestateAttr>();
}
static bool isValueType(QualType ParamType) {
return !(ParamType->isPointerType() || ParamType->isReferenceType());
}
static ConsumedState mapConsumableAttrState(const QualType QT) {
assert(isConsumableType(QT));
const ConsumableAttr *CAttr =
QT->getAsCXXRecordDecl()->getAttr<ConsumableAttr>();
switch (CAttr->getDefaultState()) {
case ConsumableAttr::Unknown:
return CS_Unknown;
case ConsumableAttr::Unconsumed:
return CS_Unconsumed;
case ConsumableAttr::Consumed:
return CS_Consumed;
}
llvm_unreachable("invalid enum");
}
static ConsumedState
mapParamTypestateAttrState(const ParamTypestateAttr *PTAttr) {
switch (PTAttr->getParamState()) {
case ParamTypestateAttr::Unknown:
return CS_Unknown;
case ParamTypestateAttr::Unconsumed:
return CS_Unconsumed;
case ParamTypestateAttr::Consumed:
return CS_Consumed;
}
llvm_unreachable("invalid_enum");
}
static ConsumedState
mapReturnTypestateAttrState(const ReturnTypestateAttr *RTSAttr) {
switch (RTSAttr->getState()) {
case ReturnTypestateAttr::Unknown:
return CS_Unknown;
case ReturnTypestateAttr::Unconsumed:
return CS_Unconsumed;
case ReturnTypestateAttr::Consumed:
return CS_Consumed;
}
llvm_unreachable("invalid enum");
}
static ConsumedState mapSetTypestateAttrState(const SetTypestateAttr *STAttr) {
switch (STAttr->getNewState()) {
case SetTypestateAttr::Unknown:
return CS_Unknown;
case SetTypestateAttr::Unconsumed:
return CS_Unconsumed;
case SetTypestateAttr::Consumed:
return CS_Consumed;
}
llvm_unreachable("invalid_enum");
}
static StringRef stateToString(ConsumedState State) {
switch (State) {
case consumed::CS_None:
return "none";
case consumed::CS_Unknown:
return "unknown";
case consumed::CS_Unconsumed:
return "unconsumed";
case consumed::CS_Consumed:
return "consumed";
}
llvm_unreachable("invalid enum");
}
static ConsumedState testsFor(const FunctionDecl *FunDecl) {
assert(isTestingFunction(FunDecl));
switch (FunDecl->getAttr<TestTypestateAttr>()->getTestState()) {
case TestTypestateAttr::Unconsumed:
return CS_Unconsumed;
case TestTypestateAttr::Consumed:
return CS_Consumed;
}
llvm_unreachable("invalid enum");
}
namespace {
struct VarTestResult {
const VarDecl *Var;
ConsumedState TestsFor;
};
} // end anonymous::VarTestResult
namespace clang {
namespace consumed {
enum EffectiveOp {
EO_And,
EO_Or
};
class PropagationInfo {
enum {
IT_None,
IT_State,
IT_Test,
IT_BinTest,
IT_Var
} InfoType;
struct BinTestTy {
const BinaryOperator *Source;
EffectiveOp EOp;
VarTestResult LTest;
VarTestResult RTest;
};
union {
ConsumedState State;
VarTestResult Test;
const VarDecl *Var;
BinTestTy BinTest;
};
QualType TempType;
public:
PropagationInfo() : InfoType(IT_None) {}
PropagationInfo(const VarTestResult &Test) : InfoType(IT_Test), Test(Test) {}
PropagationInfo(const VarDecl *Var, ConsumedState TestsFor)
: InfoType(IT_Test) {
Test.Var = Var;
Test.TestsFor = TestsFor;
}
PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp,
const VarTestResult &LTest, const VarTestResult &RTest)
: InfoType(IT_BinTest) {
BinTest.Source = Source;
BinTest.EOp = EOp;
BinTest.LTest = LTest;
BinTest.RTest = RTest;
}
PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp,
const VarDecl *LVar, ConsumedState LTestsFor,
const VarDecl *RVar, ConsumedState RTestsFor)
: InfoType(IT_BinTest) {
BinTest.Source = Source;
BinTest.EOp = EOp;
BinTest.LTest.Var = LVar;
BinTest.LTest.TestsFor = LTestsFor;
BinTest.RTest.Var = RVar;
BinTest.RTest.TestsFor = RTestsFor;
}
PropagationInfo(ConsumedState State, QualType TempType)
: InfoType(IT_State), State(State), TempType(TempType) {}
PropagationInfo(const VarDecl *Var) : InfoType(IT_Var), Var(Var) {}
const ConsumedState & getState() const {
assert(InfoType == IT_State);
return State;
}
const QualType & getTempType() const {
assert(InfoType == IT_State);
return TempType;
}
const VarTestResult & getTest() const {
assert(InfoType == IT_Test);
return Test;
}
const VarTestResult & getLTest() const {
assert(InfoType == IT_BinTest);
return BinTest.LTest;
}
const VarTestResult & getRTest() const {
assert(InfoType == IT_BinTest);
return BinTest.RTest;
}
const VarDecl * getVar() const {
assert(InfoType == IT_Var);
return Var;
}
EffectiveOp testEffectiveOp() const {
assert(InfoType == IT_BinTest);
return BinTest.EOp;
}
const BinaryOperator * testSourceNode() const {
assert(InfoType == IT_BinTest);
return BinTest.Source;
}
bool isValid() const { return InfoType != IT_None; }
bool isState() const { return InfoType == IT_State; }
bool isTest() const { return InfoType == IT_Test; }
bool isBinTest() const { return InfoType == IT_BinTest; }
bool isVar() const { return InfoType == IT_Var; }
PropagationInfo invertTest() const {
assert(InfoType == IT_Test || InfoType == IT_BinTest);
if (InfoType == IT_Test) {
return PropagationInfo(Test.Var, invertConsumedUnconsumed(Test.TestsFor));
} else if (InfoType == IT_BinTest) {
return PropagationInfo(BinTest.Source,
BinTest.EOp == EO_And ? EO_Or : EO_And,
BinTest.LTest.Var, invertConsumedUnconsumed(BinTest.LTest.TestsFor),
BinTest.RTest.Var, invertConsumedUnconsumed(BinTest.RTest.TestsFor));
} else {
return PropagationInfo();
}
}
};
class ConsumedStmtVisitor : public ConstStmtVisitor<ConsumedStmtVisitor> {
typedef llvm::DenseMap<const Stmt *, PropagationInfo> MapType;
typedef std::pair<const Stmt *, PropagationInfo> PairType;
typedef MapType::iterator InfoEntry;
typedef MapType::const_iterator ConstInfoEntry;
AnalysisDeclContext &AC;
ConsumedAnalyzer &Analyzer;
ConsumedStateMap *StateMap;
MapType PropagationMap;
void forwardInfo(const Stmt *From, const Stmt *To);
bool isLikeMoveAssignment(const CXXMethodDecl *MethodDecl);
void propagateReturnType(const Stmt *Call, const FunctionDecl *Fun,
QualType ReturnType);
inline ConsumedState getPInfoState(const PropagationInfo& PInfo) {
if (PInfo.isVar())
return StateMap->getState(PInfo.getVar());
else if (PInfo.isState())
return PInfo.getState();
else
return CS_None;
}
public:
void checkCallability(const PropagationInfo &PInfo,
const FunctionDecl *FunDecl,
SourceLocation BlameLoc);
void Visit(const Stmt *StmtNode);
void VisitBinaryOperator(const BinaryOperator *BinOp);
void VisitCallExpr(const CallExpr *Call);
void VisitCastExpr(const CastExpr *Cast);
void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *Temp);
void VisitCXXConstructExpr(const CXXConstructExpr *Call);
void VisitCXXMemberCallExpr(const CXXMemberCallExpr *Call);
void VisitCXXOperatorCallExpr(const CXXOperatorCallExpr *Call);
void VisitDeclRefExpr(const DeclRefExpr *DeclRef);
void VisitDeclStmt(const DeclStmt *DelcS);
void VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *Temp);
void VisitMemberExpr(const MemberExpr *MExpr);
void VisitParmVarDecl(const ParmVarDecl *Param);
void VisitReturnStmt(const ReturnStmt *Ret);
void VisitUnaryOperator(const UnaryOperator *UOp);
void VisitVarDecl(const VarDecl *Var);
ConsumedStmtVisitor(AnalysisDeclContext &AC, ConsumedAnalyzer &Analyzer,
ConsumedStateMap *StateMap)
: AC(AC), Analyzer(Analyzer), StateMap(StateMap) {}
PropagationInfo getInfo(const Stmt *StmtNode) const {
ConstInfoEntry Entry = PropagationMap.find(StmtNode);
if (Entry != PropagationMap.end())
return Entry->second;
else
return PropagationInfo();
}
void reset(ConsumedStateMap *NewStateMap) {
StateMap = NewStateMap;
}
};
void ConsumedStmtVisitor::checkCallability(const PropagationInfo &PInfo,
const FunctionDecl *FunDecl,
SourceLocation BlameLoc) {
if (!FunDecl->hasAttr<CallableWhenAttr>())
return;
const CallableWhenAttr *CWAttr = FunDecl->getAttr<CallableWhenAttr>();
if (PInfo.isVar()) {
const VarDecl *Var = PInfo.getVar();
ConsumedState VarState = StateMap->getState(Var);
assert(VarState != CS_None && "Invalid state");
if (isCallableInState(CWAttr, VarState))
return;
Analyzer.WarningsHandler.warnUseInInvalidState(
FunDecl->getNameAsString(), Var->getNameAsString(),
stateToString(VarState), BlameLoc);
} else if (PInfo.isState()) {
assert(PInfo.getState() != CS_None && "Invalid state");
if (isCallableInState(CWAttr, PInfo.getState()))
return;
Analyzer.WarningsHandler.warnUseOfTempInInvalidState(
FunDecl->getNameAsString(), stateToString(PInfo.getState()), BlameLoc);
}
}
void ConsumedStmtVisitor::forwardInfo(const Stmt *From, const Stmt *To) {
InfoEntry Entry = PropagationMap.find(From);
if (Entry != PropagationMap.end())
PropagationMap.insert(PairType(To, Entry->second));
}
bool ConsumedStmtVisitor::isLikeMoveAssignment(
const CXXMethodDecl *MethodDecl) {
return MethodDecl->isMoveAssignmentOperator() ||
(MethodDecl->getOverloadedOperator() == OO_Equal &&
MethodDecl->getNumParams() == 1 &&
MethodDecl->getParamDecl(0)->getType()->isRValueReferenceType());
}
void ConsumedStmtVisitor::propagateReturnType(const Stmt *Call,
const FunctionDecl *Fun,
QualType ReturnType) {
if (isConsumableType(ReturnType)) {
ConsumedState ReturnState;
if (Fun->hasAttr<ReturnTypestateAttr>())
ReturnState = mapReturnTypestateAttrState(
Fun->getAttr<ReturnTypestateAttr>());
else
ReturnState = mapConsumableAttrState(ReturnType);
PropagationMap.insert(PairType(Call,
PropagationInfo(ReturnState, ReturnType)));
}
}
void ConsumedStmtVisitor::Visit(const Stmt *StmtNode) {
ConstStmtVisitor<ConsumedStmtVisitor>::Visit(StmtNode);
for (Stmt::const_child_iterator CI = StmtNode->child_begin(),
CE = StmtNode->child_end(); CI != CE; ++CI) {
PropagationMap.erase(*CI);
}
}
void ConsumedStmtVisitor::VisitBinaryOperator(const BinaryOperator *BinOp) {
switch (BinOp->getOpcode()) {
case BO_LAnd:
case BO_LOr : {
InfoEntry LEntry = PropagationMap.find(BinOp->getLHS()),
REntry = PropagationMap.find(BinOp->getRHS());
VarTestResult LTest, RTest;
if (LEntry != PropagationMap.end() && LEntry->second.isTest()) {
LTest = LEntry->second.getTest();
} else {
LTest.Var = NULL;
LTest.TestsFor = CS_None;
}
if (REntry != PropagationMap.end() && REntry->second.isTest()) {
RTest = REntry->second.getTest();
} else {
RTest.Var = NULL;
RTest.TestsFor = CS_None;
}
if (!(LTest.Var == NULL && RTest.Var == NULL))
PropagationMap.insert(PairType(BinOp, PropagationInfo(BinOp,
static_cast<EffectiveOp>(BinOp->getOpcode() == BO_LOr), LTest, RTest)));
break;
}
case BO_PtrMemD:
case BO_PtrMemI:
forwardInfo(BinOp->getLHS(), BinOp);
break;
default:
break;
}
}
void ConsumedStmtVisitor::VisitCallExpr(const CallExpr *Call) {
if (const FunctionDecl *FunDecl =
dyn_cast_or_null<FunctionDecl>(Call->getDirectCallee())) {
// Special case for the std::move function.
// TODO: Make this more specific. (Deferred)
if (FunDecl->getNameAsString() == "move") {
forwardInfo(Call->getArg(0), Call);
return;
}
unsigned Offset = Call->getNumArgs() - FunDecl->getNumParams();
for (unsigned Index = Offset; Index < Call->getNumArgs(); ++Index) {
const ParmVarDecl *Param = FunDecl->getParamDecl(Index - Offset);
QualType ParamType = Param->getType();
InfoEntry Entry = PropagationMap.find(Call->getArg(Index));
if (Entry == PropagationMap.end() ||
!(Entry->second.isState() || Entry->second.isVar()))
continue;
PropagationInfo PInfo = Entry->second;
// Check that the parameter is in the correct state.
if (Param->hasAttr<ParamTypestateAttr>()) {
ConsumedState ParamState =
PInfo.isState() ? PInfo.getState() :
StateMap->getState(PInfo.getVar());
ConsumedState ExpectedState =
mapParamTypestateAttrState(Param->getAttr<ParamTypestateAttr>());
if (ParamState != ExpectedState)
Analyzer.WarningsHandler.warnParamTypestateMismatch(
Call->getArg(Index - Offset)->getExprLoc(),
stateToString(ExpectedState), stateToString(ParamState));
}
if (!Entry->second.isVar())
continue;
// Adjust state on the caller side.
if (isRValueRefish(ParamType)) {
StateMap->setState(PInfo.getVar(), consumed::CS_Consumed);
} else if (Param->hasAttr<ReturnTypestateAttr>()) {
StateMap->setState(PInfo.getVar(),
mapReturnTypestateAttrState(Param->getAttr<ReturnTypestateAttr>()));
} else if (!isValueType(ParamType) &&
!ParamType->getPointeeType().isConstQualified()) {
StateMap->setState(PInfo.getVar(), consumed::CS_Unknown);
}
}
QualType RetType = FunDecl->getCallResultType();
if (RetType->isReferenceType())
RetType = RetType->getPointeeType();
propagateReturnType(Call, FunDecl, RetType);
}
}
void ConsumedStmtVisitor::VisitCastExpr(const CastExpr *Cast) {
forwardInfo(Cast->getSubExpr(), Cast);
}
void ConsumedStmtVisitor::VisitCXXBindTemporaryExpr(
const CXXBindTemporaryExpr *Temp) {
forwardInfo(Temp->getSubExpr(), Temp);
}
void ConsumedStmtVisitor::VisitCXXConstructExpr(const CXXConstructExpr *Call) {
CXXConstructorDecl *Constructor = Call->getConstructor();
ASTContext &CurrContext = AC.getASTContext();
QualType ThisType = Constructor->getThisType(CurrContext)->getPointeeType();
if (!isConsumableType(ThisType))
return;
// FIXME: What should happen if someone annotates the move constructor?
if (Constructor->hasAttr<ReturnTypestateAttr>()) {
ReturnTypestateAttr *RTAttr = Constructor->getAttr<ReturnTypestateAttr>();
ConsumedState RetState = mapReturnTypestateAttrState(RTAttr);
PropagationMap.insert(PairType(Call, PropagationInfo(RetState, ThisType)));
} else if (Constructor->isDefaultConstructor()) {
PropagationMap.insert(PairType(Call,
PropagationInfo(consumed::CS_Consumed, ThisType)));
} else if (Constructor->isMoveConstructor()) {
InfoEntry Entry = PropagationMap.find(Call->getArg(0));
if (Entry != PropagationMap.end()) {
PropagationInfo PInfo = Entry->second;
if (PInfo.isVar()) {
const VarDecl* Var = PInfo.getVar();
PropagationMap.insert(PairType(Call,
PropagationInfo(StateMap->getState(Var), ThisType)));
StateMap->setState(Var, consumed::CS_Consumed);
} else {
PropagationMap.insert(PairType(Call, PInfo));
}
}
} else if (Constructor->isCopyConstructor()) {
forwardInfo(Call->getArg(0), Call);
} else {
ConsumedState RetState = mapConsumableAttrState(ThisType);
PropagationMap.insert(PairType(Call, PropagationInfo(RetState, ThisType)));
}
}
void ConsumedStmtVisitor::VisitCXXMemberCallExpr(
const CXXMemberCallExpr *Call) {
VisitCallExpr(Call);
InfoEntry Entry = PropagationMap.find(Call->getCallee()->IgnoreParens());
if (Entry != PropagationMap.end()) {
PropagationInfo PInfo = Entry->second;
const CXXMethodDecl *MethodDecl = Call->getMethodDecl();
checkCallability(PInfo, MethodDecl, Call->getExprLoc());
if (PInfo.isVar()) {
if (isTestingFunction(MethodDecl))
PropagationMap.insert(PairType(Call,
PropagationInfo(PInfo.getVar(), testsFor(MethodDecl))));
else if (MethodDecl->hasAttr<SetTypestateAttr>())
StateMap->setState(PInfo.getVar(),
mapSetTypestateAttrState(MethodDecl->getAttr<SetTypestateAttr>()));
}
}
}
void ConsumedStmtVisitor::VisitCXXOperatorCallExpr(
const CXXOperatorCallExpr *Call) {
const FunctionDecl *FunDecl =
dyn_cast_or_null<FunctionDecl>(Call->getDirectCallee());
if (!FunDecl) return;
if (isa<CXXMethodDecl>(FunDecl) &&
isLikeMoveAssignment(cast<CXXMethodDecl>(FunDecl))) {
InfoEntry LEntry = PropagationMap.find(Call->getArg(0));
InfoEntry REntry = PropagationMap.find(Call->getArg(1));
PropagationInfo LPInfo, RPInfo;
if (LEntry != PropagationMap.end() &&
REntry != PropagationMap.end()) {
LPInfo = LEntry->second;
RPInfo = REntry->second;
if (LPInfo.isVar() && RPInfo.isVar()) {
StateMap->setState(LPInfo.getVar(),
StateMap->getState(RPInfo.getVar()));
StateMap->setState(RPInfo.getVar(), consumed::CS_Consumed);
PropagationMap.insert(PairType(Call, LPInfo));
} else if (LPInfo.isVar() && !RPInfo.isVar()) {
StateMap->setState(LPInfo.getVar(), RPInfo.getState());
PropagationMap.insert(PairType(Call, LPInfo));
} else if (!LPInfo.isVar() && RPInfo.isVar()) {
PropagationMap.insert(PairType(Call,
PropagationInfo(StateMap->getState(RPInfo.getVar()),
LPInfo.getTempType())));
StateMap->setState(RPInfo.getVar(), consumed::CS_Consumed);
} else {
PropagationMap.insert(PairType(Call, RPInfo));
}
} else if (LEntry != PropagationMap.end() &&
REntry == PropagationMap.end()) {
LPInfo = LEntry->second;
if (LPInfo.isVar()) {
StateMap->setState(LPInfo.getVar(), consumed::CS_Unknown);
PropagationMap.insert(PairType(Call, LPInfo));
} else if (LPInfo.isState()) {
PropagationMap.insert(PairType(Call,
PropagationInfo(consumed::CS_Unknown, LPInfo.getTempType())));
}
} else if (LEntry == PropagationMap.end() &&
REntry != PropagationMap.end()) {
if (REntry->second.isVar())
StateMap->setState(REntry->second.getVar(), consumed::CS_Consumed);
}
} else {
VisitCallExpr(Call);
InfoEntry Entry = PropagationMap.find(Call->getArg(0));
if (Entry != PropagationMap.end()) {
PropagationInfo PInfo = Entry->second;
checkCallability(PInfo, FunDecl, Call->getExprLoc());
if (PInfo.isVar()) {
if (isTestingFunction(FunDecl))
PropagationMap.insert(PairType(Call,
PropagationInfo(PInfo.getVar(), testsFor(FunDecl))));
else if (FunDecl->hasAttr<SetTypestateAttr>())
StateMap->setState(PInfo.getVar(),
mapSetTypestateAttrState(FunDecl->getAttr<SetTypestateAttr>()));
}
}
}
}
void ConsumedStmtVisitor::VisitDeclRefExpr(const DeclRefExpr *DeclRef) {
if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(DeclRef->getDecl()))
if (StateMap->getState(Var) != consumed::CS_None)
PropagationMap.insert(PairType(DeclRef, PropagationInfo(Var)));
}
void ConsumedStmtVisitor::VisitDeclStmt(const DeclStmt *DeclS) {
for (DeclStmt::const_decl_iterator DI = DeclS->decl_begin(),
DE = DeclS->decl_end(); DI != DE; ++DI) {
if (isa<VarDecl>(*DI)) VisitVarDecl(cast<VarDecl>(*DI));
}
if (DeclS->isSingleDecl())
if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(DeclS->getSingleDecl()))
PropagationMap.insert(PairType(DeclS, PropagationInfo(Var)));
}
void ConsumedStmtVisitor::VisitMaterializeTemporaryExpr(
const MaterializeTemporaryExpr *Temp) {
forwardInfo(Temp->GetTemporaryExpr(), Temp);
}
void ConsumedStmtVisitor::VisitMemberExpr(const MemberExpr *MExpr) {
forwardInfo(MExpr->getBase(), MExpr);
}
void ConsumedStmtVisitor::VisitParmVarDecl(const ParmVarDecl *Param) {
QualType ParamType = Param->getType();
ConsumedState ParamState = consumed::CS_None;
if (Param->hasAttr<ParamTypestateAttr>()) {
const ParamTypestateAttr *PTAttr = Param->getAttr<ParamTypestateAttr>();
ParamState = mapParamTypestateAttrState(PTAttr);
} else if (isConsumableType(ParamType)) {
ParamState = mapConsumableAttrState(ParamType);
} else if (isRValueRefish(ParamType) &&
isConsumableType(ParamType->getPointeeType())) {
ParamState = mapConsumableAttrState(ParamType->getPointeeType());
} else if (ParamType->isReferenceType() &&
isConsumableType(ParamType->getPointeeType())) {
ParamState = consumed::CS_Unknown;
}
if (ParamState != CS_None)
StateMap->setState(Param, ParamState);
}
void ConsumedStmtVisitor::VisitReturnStmt(const ReturnStmt *Ret) {
ConsumedState ExpectedState = Analyzer.getExpectedReturnState();
if (ExpectedState != CS_None) {
InfoEntry Entry = PropagationMap.find(Ret->getRetValue());
if (Entry != PropagationMap.end()) {
assert(Entry->second.isState() || Entry->second.isVar());
ConsumedState RetState = Entry->second.isState() ?
Entry->second.getState() : StateMap->getState(Entry->second.getVar());
if (RetState != ExpectedState)
Analyzer.WarningsHandler.warnReturnTypestateMismatch(
Ret->getReturnLoc(), stateToString(ExpectedState),
stateToString(RetState));
}
}
StateMap->checkParamsForReturnTypestate(Ret->getLocStart(),
Analyzer.WarningsHandler);
}
void ConsumedStmtVisitor::VisitUnaryOperator(const UnaryOperator *UOp) {
InfoEntry Entry = PropagationMap.find(UOp->getSubExpr()->IgnoreParens());
if (Entry == PropagationMap.end()) return;
switch (UOp->getOpcode()) {
case UO_AddrOf:
PropagationMap.insert(PairType(UOp, Entry->second));
break;
case UO_LNot:
if (Entry->second.isTest() || Entry->second.isBinTest())
PropagationMap.insert(PairType(UOp, Entry->second.invertTest()));
break;
default:
break;
}
}
// TODO: See if I need to check for reference types here.
void ConsumedStmtVisitor::VisitVarDecl(const VarDecl *Var) {
if (isConsumableType(Var->getType())) {
if (Var->hasInit()) {
MapType::iterator VIT = PropagationMap.find(Var->getInit());
if (VIT != PropagationMap.end()) {
PropagationInfo PInfo = VIT->second;
ConsumedState St = getPInfoState(PInfo);
if (St != consumed::CS_None) {
StateMap->setState(Var, St);
return;
}
}
}
// Otherwise
StateMap->setState(Var, consumed::CS_Unknown);
}
}
}} // end clang::consumed::ConsumedStmtVisitor
namespace clang {
namespace consumed {
void splitVarStateForIf(const IfStmt * IfNode, const VarTestResult &Test,
ConsumedStateMap *ThenStates,
ConsumedStateMap *ElseStates) {
ConsumedState VarState = ThenStates->getState(Test.Var);
if (VarState == CS_Unknown) {
ThenStates->setState(Test.Var, Test.TestsFor);
ElseStates->setState(Test.Var, invertConsumedUnconsumed(Test.TestsFor));
} else if (VarState == invertConsumedUnconsumed(Test.TestsFor)) {
ThenStates->markUnreachable();
} else if (VarState == Test.TestsFor) {
ElseStates->markUnreachable();
}
}
void splitVarStateForIfBinOp(const PropagationInfo &PInfo,
ConsumedStateMap *ThenStates, ConsumedStateMap *ElseStates) {
const VarTestResult &LTest = PInfo.getLTest(),
&RTest = PInfo.getRTest();
ConsumedState LState = LTest.Var ? ThenStates->getState(LTest.Var) : CS_None,
RState = RTest.Var ? ThenStates->getState(RTest.Var) : CS_None;
if (LTest.Var) {
if (PInfo.testEffectiveOp() == EO_And) {
if (LState == CS_Unknown) {
ThenStates->setState(LTest.Var, LTest.TestsFor);
} else if (LState == invertConsumedUnconsumed(LTest.TestsFor)) {
ThenStates->markUnreachable();
} else if (LState == LTest.TestsFor && isKnownState(RState)) {
if (RState == RTest.TestsFor)
ElseStates->markUnreachable();
else
ThenStates->markUnreachable();
}
} else {
if (LState == CS_Unknown) {
ElseStates->setState(LTest.Var,
invertConsumedUnconsumed(LTest.TestsFor));
} else if (LState == LTest.TestsFor) {
ElseStates->markUnreachable();
} else if (LState == invertConsumedUnconsumed(LTest.TestsFor) &&
isKnownState(RState)) {
if (RState == RTest.TestsFor)
ElseStates->markUnreachable();
else
ThenStates->markUnreachable();
}
}
}
if (RTest.Var) {
if (PInfo.testEffectiveOp() == EO_And) {
if (RState == CS_Unknown)
ThenStates->setState(RTest.Var, RTest.TestsFor);
else if (RState == invertConsumedUnconsumed(RTest.TestsFor))
ThenStates->markUnreachable();
} else {
if (RState == CS_Unknown)
ElseStates->setState(RTest.Var,
invertConsumedUnconsumed(RTest.TestsFor));
else if (RState == RTest.TestsFor)
ElseStates->markUnreachable();
}
}
}
bool ConsumedBlockInfo::allBackEdgesVisited(const CFGBlock *CurrBlock,
const CFGBlock *TargetBlock) {
assert(CurrBlock && "Block pointer must not be NULL");
assert(TargetBlock && "TargetBlock pointer must not be NULL");
unsigned int CurrBlockOrder = VisitOrder[CurrBlock->getBlockID()];
for (CFGBlock::const_pred_iterator PI = TargetBlock->pred_begin(),
PE = TargetBlock->pred_end(); PI != PE; ++PI) {
if (*PI && CurrBlockOrder < VisitOrder[(*PI)->getBlockID()] )
return false;
}
return true;
}
void ConsumedBlockInfo::addInfo(const CFGBlock *Block,
ConsumedStateMap *StateMap,
bool &AlreadyOwned) {
assert(Block && "Block pointer must not be NULL");
ConsumedStateMap *Entry = StateMapsArray[Block->getBlockID()];
if (Entry) {
Entry->intersect(StateMap);
} else if (AlreadyOwned) {
StateMapsArray[Block->getBlockID()] = new ConsumedStateMap(*StateMap);
} else {
StateMapsArray[Block->getBlockID()] = StateMap;
AlreadyOwned = true;
}
}
void ConsumedBlockInfo::addInfo(const CFGBlock *Block,
ConsumedStateMap *StateMap) {
assert(Block != NULL && "Block pointer must not be NULL");
ConsumedStateMap *Entry = StateMapsArray[Block->getBlockID()];
if (Entry) {
Entry->intersect(StateMap);
delete StateMap;
} else {
StateMapsArray[Block->getBlockID()] = StateMap;
}
}
ConsumedStateMap* ConsumedBlockInfo::borrowInfo(const CFGBlock *Block) {
assert(Block && "Block pointer must not be NULL");
assert(StateMapsArray[Block->getBlockID()] && "Block has no block info");
return StateMapsArray[Block->getBlockID()];
}
void ConsumedBlockInfo::discardInfo(const CFGBlock *Block) {
unsigned int BlockID = Block->getBlockID();
delete StateMapsArray[BlockID];
StateMapsArray[BlockID] = NULL;
}
ConsumedStateMap* ConsumedBlockInfo::getInfo(const CFGBlock *Block) {
assert(Block && "Block pointer must not be NULL");
ConsumedStateMap *StateMap = StateMapsArray[Block->getBlockID()];
if (isBackEdgeTarget(Block)) {
return new ConsumedStateMap(*StateMap);
} else {
StateMapsArray[Block->getBlockID()] = NULL;
return StateMap;
}
}
bool ConsumedBlockInfo::isBackEdge(const CFGBlock *From, const CFGBlock *To) {
assert(From && "From block must not be NULL");
assert(To && "From block must not be NULL");
return VisitOrder[From->getBlockID()] > VisitOrder[To->getBlockID()];
}
bool ConsumedBlockInfo::isBackEdgeTarget(const CFGBlock *Block) {
assert(Block != NULL && "Block pointer must not be NULL");
// Anything with less than two predecessors can't be the target of a back
// edge.
if (Block->pred_size() < 2)
return false;
unsigned int BlockVisitOrder = VisitOrder[Block->getBlockID()];
for (CFGBlock::const_pred_iterator PI = Block->pred_begin(),
PE = Block->pred_end(); PI != PE; ++PI) {
if (*PI && BlockVisitOrder < VisitOrder[(*PI)->getBlockID()])
return true;
}
return false;
}
void ConsumedStateMap::checkParamsForReturnTypestate(SourceLocation BlameLoc,
ConsumedWarningsHandlerBase &WarningsHandler) const {
ConsumedState ExpectedState;
for (MapType::const_iterator DMI = Map.begin(), DME = Map.end(); DMI != DME;
++DMI) {
if (isa<ParmVarDecl>(DMI->first)) {
const ParmVarDecl *Param = cast<ParmVarDecl>(DMI->first);
if (!Param->hasAttr<ReturnTypestateAttr>()) continue;
ExpectedState =
mapReturnTypestateAttrState(Param->getAttr<ReturnTypestateAttr>());
if (DMI->second != ExpectedState) {
WarningsHandler.warnParamReturnTypestateMismatch(BlameLoc,
Param->getNameAsString(), stateToString(ExpectedState),
stateToString(DMI->second));
}
}
}
}
ConsumedState ConsumedStateMap::getState(const VarDecl *Var) const {
MapType::const_iterator Entry = Map.find(Var);
if (Entry != Map.end()) {
return Entry->second;
} else {
return CS_None;
}
}
void ConsumedStateMap::intersect(const ConsumedStateMap *Other) {
ConsumedState LocalState;
if (this->From && this->From == Other->From && !Other->Reachable) {
this->markUnreachable();
return;
}
for (MapType::const_iterator DMI = Other->Map.begin(), DME = Other->Map.end();
DMI != DME; ++DMI) {
LocalState = this->getState(DMI->first);
if (LocalState == CS_None)
continue;
if (LocalState != DMI->second)
Map[DMI->first] = CS_Unknown;
}
}
void ConsumedStateMap::intersectAtLoopHead(const CFGBlock *LoopHead,
const CFGBlock *LoopBack, const ConsumedStateMap *LoopBackStates,
ConsumedWarningsHandlerBase &WarningsHandler) {
ConsumedState LocalState;
SourceLocation BlameLoc = getLastStmtLoc(LoopBack);
for (MapType::const_iterator DMI = LoopBackStates->Map.begin(),
DME = LoopBackStates->Map.end(); DMI != DME; ++DMI) {
LocalState = this->getState(DMI->first);
if (LocalState == CS_None)
continue;
if (LocalState != DMI->second) {
Map[DMI->first] = CS_Unknown;
WarningsHandler.warnLoopStateMismatch(
BlameLoc, DMI->first->getNameAsString());
}
}
}
void ConsumedStateMap::markUnreachable() {
this->Reachable = false;
Map.clear();
}
void ConsumedStateMap::setState(const VarDecl *Var, ConsumedState State) {
Map[Var] = State;
}
void ConsumedStateMap::remove(const VarDecl *Var) {
Map.erase(Var);
}
bool ConsumedStateMap::operator!=(const ConsumedStateMap *Other) const {
for (MapType::const_iterator DMI = Other->Map.begin(), DME = Other->Map.end();
DMI != DME; ++DMI) {
if (this->getState(DMI->first) != DMI->second)
return true;
}
return false;
}
void ConsumedAnalyzer::determineExpectedReturnState(AnalysisDeclContext &AC,
const FunctionDecl *D) {
QualType ReturnType;
if (const CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
ASTContext &CurrContext = AC.getASTContext();
ReturnType = Constructor->getThisType(CurrContext)->getPointeeType();
} else
ReturnType = D->getCallResultType();
if (D->hasAttr<ReturnTypestateAttr>()) {
const ReturnTypestateAttr *RTSAttr = D->getAttr<ReturnTypestateAttr>();
const CXXRecordDecl *RD = ReturnType->getAsCXXRecordDecl();
if (!RD || !RD->hasAttr<ConsumableAttr>()) {
// FIXME: This should be removed when template instantiation propagates
// attributes at template specialization definition, not
// declaration. When it is removed the test needs to be enabled
// in SemaDeclAttr.cpp.
WarningsHandler.warnReturnTypestateForUnconsumableType(
RTSAttr->getLocation(), ReturnType.getAsString());
ExpectedReturnState = CS_None;
} else
ExpectedReturnState = mapReturnTypestateAttrState(RTSAttr);
} else if (isConsumableType(ReturnType))
ExpectedReturnState = mapConsumableAttrState(ReturnType);
else
ExpectedReturnState = CS_None;
}
bool ConsumedAnalyzer::splitState(const CFGBlock *CurrBlock,
const ConsumedStmtVisitor &Visitor) {
OwningPtr<ConsumedStateMap> FalseStates(new ConsumedStateMap(*CurrStates));
PropagationInfo PInfo;
if (const IfStmt *IfNode =
dyn_cast_or_null<IfStmt>(CurrBlock->getTerminator().getStmt())) {
const Stmt *Cond = IfNode->getCond();
PInfo = Visitor.getInfo(Cond);
if (!PInfo.isValid() && isa<BinaryOperator>(Cond))
PInfo = Visitor.getInfo(cast<BinaryOperator>(Cond)->getRHS());
if (PInfo.isTest()) {
CurrStates->setSource(Cond);
FalseStates->setSource(Cond);
splitVarStateForIf(IfNode, PInfo.getTest(), CurrStates,
FalseStates.get());
} else if (PInfo.isBinTest()) {
CurrStates->setSource(PInfo.testSourceNode());
FalseStates->setSource(PInfo.testSourceNode());
splitVarStateForIfBinOp(PInfo, CurrStates, FalseStates.get());
} else {
return false;
}
} else if (const BinaryOperator *BinOp =
dyn_cast_or_null<BinaryOperator>(CurrBlock->getTerminator().getStmt())) {
PInfo = Visitor.getInfo(BinOp->getLHS());
if (!PInfo.isTest()) {
if ((BinOp = dyn_cast_or_null<BinaryOperator>(BinOp->getLHS()))) {
PInfo = Visitor.getInfo(BinOp->getRHS());
if (!PInfo.isTest())
return false;
} else {
return false;
}
}
CurrStates->setSource(BinOp);
FalseStates->setSource(BinOp);
const VarTestResult &Test = PInfo.getTest();
ConsumedState VarState = CurrStates->getState(Test.Var);
if (BinOp->getOpcode() == BO_LAnd) {
if (VarState == CS_Unknown)
CurrStates->setState(Test.Var, Test.TestsFor);
else if (VarState == invertConsumedUnconsumed(Test.TestsFor))
CurrStates->markUnreachable();
} else if (BinOp->getOpcode() == BO_LOr) {
if (VarState == CS_Unknown)
FalseStates->setState(Test.Var,
invertConsumedUnconsumed(Test.TestsFor));
else if (VarState == Test.TestsFor)
FalseStates->markUnreachable();
}
} else {
return false;
}
CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin();
if (*SI)
BlockInfo.addInfo(*SI, CurrStates);
else
delete CurrStates;
if (*++SI)
BlockInfo.addInfo(*SI, FalseStates.take());
CurrStates = NULL;
return true;
}
void ConsumedAnalyzer::run(AnalysisDeclContext &AC) {
const FunctionDecl *D = dyn_cast_or_null<FunctionDecl>(AC.getDecl());
if (!D)
return;
CFG *CFGraph = AC.getCFG();
if (!CFGraph)
return;
determineExpectedReturnState(AC, D);
PostOrderCFGView *SortedGraph = AC.getAnalysis<PostOrderCFGView>();
// AC.getCFG()->viewCFG(LangOptions());
BlockInfo = ConsumedBlockInfo(CFGraph->getNumBlockIDs(), SortedGraph);
CurrStates = new ConsumedStateMap();
ConsumedStmtVisitor Visitor(AC, *this, CurrStates);
// Add all trackable parameters to the state map.
for (FunctionDecl::param_const_iterator PI = D->param_begin(),
PE = D->param_end(); PI != PE; ++PI) {
Visitor.VisitParmVarDecl(*PI);
}
// Visit all of the function's basic blocks.
for (PostOrderCFGView::iterator I = SortedGraph->begin(),
E = SortedGraph->end(); I != E; ++I) {
const CFGBlock *CurrBlock = *I;
if (CurrStates == NULL)
CurrStates = BlockInfo.getInfo(CurrBlock);
if (!CurrStates) {
continue;
} else if (!CurrStates->isReachable()) {
delete CurrStates;
CurrStates = NULL;
continue;
}
Visitor.reset(CurrStates);
// Visit all of the basic block's statements.
for (CFGBlock::const_iterator BI = CurrBlock->begin(),
BE = CurrBlock->end(); BI != BE; ++BI) {
switch (BI->getKind()) {
case CFGElement::Statement:
Visitor.Visit(BI->castAs<CFGStmt>().getStmt());
break;
case CFGElement::TemporaryDtor: {
const CFGTemporaryDtor DTor = BI->castAs<CFGTemporaryDtor>();
const CXXBindTemporaryExpr *BTE = DTor.getBindTemporaryExpr();
PropagationInfo PInfo = Visitor.getInfo(BTE);
if (PInfo.isValid())
Visitor.checkCallability(PInfo,
DTor.getDestructorDecl(AC.getASTContext()),
BTE->getExprLoc());
break;
}
case CFGElement::AutomaticObjectDtor: {
const CFGAutomaticObjDtor DTor = BI->castAs<CFGAutomaticObjDtor>();
const VarDecl *Var = DTor.getVarDecl();
ConsumedState VarState = CurrStates->getState(Var);
if (VarState != CS_None) {
PropagationInfo PInfo(Var);
Visitor.checkCallability(PInfo,
DTor.getDestructorDecl(AC.getASTContext()),
getLastStmtLoc(CurrBlock));
CurrStates->remove(Var);
}
break;
}
default:
break;
}
}
// TODO: Handle other forms of branching with precision, including while-
// and for-loops. (Deferred)
if (!splitState(CurrBlock, Visitor)) {
CurrStates->setSource(NULL);
if (CurrBlock->succ_size() > 1 ||
(CurrBlock->succ_size() == 1 &&
(*CurrBlock->succ_begin())->pred_size() > 1)) {
bool OwnershipTaken = false;
for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(),
SE = CurrBlock->succ_end(); SI != SE; ++SI) {
if (*SI == NULL) continue;
if (BlockInfo.isBackEdge(CurrBlock, *SI)) {
BlockInfo.borrowInfo(*SI)->intersectAtLoopHead(*SI, CurrBlock,
CurrStates,
WarningsHandler);
if (BlockInfo.allBackEdgesVisited(*SI, CurrBlock))
BlockInfo.discardInfo(*SI);
} else {
BlockInfo.addInfo(*SI, CurrStates, OwnershipTaken);
}
}
if (!OwnershipTaken)
delete CurrStates;
CurrStates = NULL;
}
}
if (CurrBlock == &AC.getCFG()->getExit() &&
D->getCallResultType()->isVoidType())
CurrStates->checkParamsForReturnTypestate(D->getLocation(),
WarningsHandler);
} // End of block iterator.
// Delete the last existing state map.
delete CurrStates;
WarningsHandler.emitDiagnostics();
}
}} // end namespace clang::consumed
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