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llvm-project/clang/lib/StaticAnalyzer/Core/BugReporter.cpp

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// BugReporter.cpp - Generate PathDiagnostics for Bugs ------------*- C++ -*--//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines BugReporter, a utility class for generating
// PathDiagnostics.
//
//===----------------------------------------------------------------------===//
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
#include "clang/AST/ASTContext.h"
#include "clang/Analysis/CFG.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ParentMap.h"
#include "clang/AST/StmtObjC.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Analysis/ProgramPoint.h"
#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include <queue>
using namespace clang;
using namespace ento;
BugReporterVisitor::~BugReporterVisitor() {}
void BugReporterContext::anchor() {}
//===----------------------------------------------------------------------===//
// Helper routines for walking the ExplodedGraph and fetching statements.
//===----------------------------------------------------------------------===//
static inline const Stmt *GetStmt(const ProgramPoint &P) {
if (const StmtPoint* SP = dyn_cast<StmtPoint>(&P))
return SP->getStmt();
else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P))
return BE->getSrc()->getTerminator();
return 0;
}
static inline const ExplodedNode*
GetPredecessorNode(const ExplodedNode *N) {
return N->pred_empty() ? NULL : *(N->pred_begin());
}
static inline const ExplodedNode*
GetSuccessorNode(const ExplodedNode *N) {
return N->succ_empty() ? NULL : *(N->succ_begin());
}
static const Stmt *GetPreviousStmt(const ExplodedNode *N) {
for (N = GetPredecessorNode(N); N; N = GetPredecessorNode(N))
if (const Stmt *S = GetStmt(N->getLocation()))
return S;
return 0;
}
static const Stmt *GetNextStmt(const ExplodedNode *N) {
for (N = GetSuccessorNode(N); N; N = GetSuccessorNode(N))
if (const Stmt *S = GetStmt(N->getLocation())) {
// Check if the statement is '?' or '&&'/'||'. These are "merges",
// not actual statement points.
switch (S->getStmtClass()) {
case Stmt::ChooseExprClass:
case Stmt::BinaryConditionalOperatorClass: continue;
case Stmt::ConditionalOperatorClass: continue;
case Stmt::BinaryOperatorClass: {
BinaryOperatorKind Op = cast<BinaryOperator>(S)->getOpcode();
if (Op == BO_LAnd || Op == BO_LOr)
continue;
break;
}
default:
break;
}
return S;
}
return 0;
}
static inline const Stmt*
GetCurrentOrPreviousStmt(const ExplodedNode *N) {
if (const Stmt *S = GetStmt(N->getLocation()))
return S;
return GetPreviousStmt(N);
}
static inline const Stmt*
GetCurrentOrNextStmt(const ExplodedNode *N) {
if (const Stmt *S = GetStmt(N->getLocation()))
return S;
return GetNextStmt(N);
}
//===----------------------------------------------------------------------===//
// Diagnostic cleanup.
//===----------------------------------------------------------------------===//
/// Recursively scan through a path and prune out calls and macros pieces
/// that aren't needed. Return true if afterwards the path contains
/// "interesting stuff" which means it should be pruned from the parent path.
static bool RemoveUneededCalls(PathPieces &pieces) {
bool containsSomethingInteresting = false;
const unsigned N = pieces.size();
for (unsigned i = 0 ; i < N ; ++i) {
// Remove the front piece from the path. If it is still something we
// want to keep once we are done, we will push it back on the end.
IntrusiveRefCntPtr<PathDiagnosticPiece> piece(pieces.front());
pieces.pop_front();
switch (piece->getKind()) {
case PathDiagnosticPiece::Call: {
PathDiagnosticCallPiece *call = cast<PathDiagnosticCallPiece>(piece);
// Recursively clean out the subclass. Keep this call around if
// it contains any informative diagnostics.
if (!RemoveUneededCalls(call->path))
continue;
containsSomethingInteresting = true;
break;
}
case PathDiagnosticPiece::Macro: {
PathDiagnosticMacroPiece *macro = cast<PathDiagnosticMacroPiece>(piece);
if (!RemoveUneededCalls(macro->subPieces))
continue;
containsSomethingInteresting = true;
break;
}
case PathDiagnosticPiece::Event: {
PathDiagnosticEventPiece *event = cast<PathDiagnosticEventPiece>(piece);
// We never throw away an event, but we do throw it away wholesale
// as part of a path if we throw the entire path away.
if (!event->isPrunable())
containsSomethingInteresting = true;
break;
}
case PathDiagnosticPiece::ControlFlow:
break;
}
pieces.push_back(piece);
}
return containsSomethingInteresting;
}
//===----------------------------------------------------------------------===//
// PathDiagnosticBuilder and its associated routines and helper objects.
//===----------------------------------------------------------------------===//
typedef llvm::DenseMap<const ExplodedNode*,
const ExplodedNode*> NodeBackMap;
namespace {
class NodeMapClosure : public BugReport::NodeResolver {
NodeBackMap& M;
public:
NodeMapClosure(NodeBackMap *m) : M(*m) {}
~NodeMapClosure() {}
const ExplodedNode *getOriginalNode(const ExplodedNode *N) {
NodeBackMap::iterator I = M.find(N);
return I == M.end() ? 0 : I->second;
}
};
class PathDiagnosticBuilder : public BugReporterContext {
BugReport *R;
PathDiagnosticConsumer *PDC;
OwningPtr<ParentMap> PM;
NodeMapClosure NMC;
public:
const LocationContext *LC;
PathDiagnosticBuilder(GRBugReporter &br,
BugReport *r, NodeBackMap *Backmap,
PathDiagnosticConsumer *pdc)
: BugReporterContext(br),
R(r), PDC(pdc), NMC(Backmap), LC(r->getErrorNode()->getLocationContext())
{}
PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N);
PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os,
const ExplodedNode *N);
BugReport *getBugReport() { return R; }
Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); }
ParentMap& getParentMap() { return LC->getParentMap(); }
const Stmt *getParent(const Stmt *S) {
return getParentMap().getParent(S);
}
virtual NodeMapClosure& getNodeResolver() { return NMC; }
PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S);
PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const {
return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Extensive;
}
bool supportsLogicalOpControlFlow() const {
return PDC ? PDC->supportsLogicalOpControlFlow() : true;
}
};
} // end anonymous namespace
PathDiagnosticLocation
PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) {
if (const Stmt *S = GetNextStmt(N))
return PathDiagnosticLocation(S, getSourceManager(), LC);
return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(),
getSourceManager());
}
PathDiagnosticLocation
PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os,
const ExplodedNode *N) {
// Slow, but probably doesn't matter.
if (os.str().empty())
os << ' ';
const PathDiagnosticLocation &Loc = ExecutionContinues(N);
if (Loc.asStmt())
os << "Execution continues on line "
<< getSourceManager().getExpansionLineNumber(Loc.asLocation())
<< '.';
else {
os << "Execution jumps to the end of the ";
const Decl *D = N->getLocationContext()->getDecl();
if (isa<ObjCMethodDecl>(D))
os << "method";
else if (isa<FunctionDecl>(D))
os << "function";
else {
assert(isa<BlockDecl>(D));
os << "anonymous block";
}
os << '.';
}
return Loc;
}
static bool IsNested(const Stmt *S, ParentMap &PM) {
if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S)))
return true;
const Stmt *Parent = PM.getParentIgnoreParens(S);
if (Parent)
switch (Parent->getStmtClass()) {
case Stmt::ForStmtClass:
case Stmt::DoStmtClass:
case Stmt::WhileStmtClass:
return true;
default:
break;
}
return false;
}
PathDiagnosticLocation
PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) {
assert(S && "Null Stmt *passed to getEnclosingStmtLocation");
ParentMap &P = getParentMap();
SourceManager &SMgr = getSourceManager();
while (IsNested(S, P)) {
const Stmt *Parent = P.getParentIgnoreParens(S);
if (!Parent)
break;
switch (Parent->getStmtClass()) {
case Stmt::BinaryOperatorClass: {
const BinaryOperator *B = cast<BinaryOperator>(Parent);
if (B->isLogicalOp())
return PathDiagnosticLocation(S, SMgr, LC);
break;
}
case Stmt::CompoundStmtClass:
case Stmt::StmtExprClass:
return PathDiagnosticLocation(S, SMgr, LC);
case Stmt::ChooseExprClass:
// Similar to '?' if we are referring to condition, just have the edge
// point to the entire choose expression.
if (cast<ChooseExpr>(Parent)->getCond() == S)
return PathDiagnosticLocation(Parent, SMgr, LC);
else
return PathDiagnosticLocation(S, SMgr, LC);
case Stmt::BinaryConditionalOperatorClass:
case Stmt::ConditionalOperatorClass:
// For '?', if we are referring to condition, just have the edge point
// to the entire '?' expression.
if (cast<AbstractConditionalOperator>(Parent)->getCond() == S)
return PathDiagnosticLocation(Parent, SMgr, LC);
else
return PathDiagnosticLocation(S, SMgr, LC);
case Stmt::DoStmtClass:
return PathDiagnosticLocation(S, SMgr, LC);
case Stmt::ForStmtClass:
if (cast<ForStmt>(Parent)->getBody() == S)
return PathDiagnosticLocation(S, SMgr, LC);
break;
case Stmt::IfStmtClass:
if (cast<IfStmt>(Parent)->getCond() != S)
return PathDiagnosticLocation(S, SMgr, LC);
break;
case Stmt::ObjCForCollectionStmtClass:
if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S)
return PathDiagnosticLocation(S, SMgr, LC);
break;
case Stmt::WhileStmtClass:
if (cast<WhileStmt>(Parent)->getCond() != S)
return PathDiagnosticLocation(S, SMgr, LC);
break;
default:
break;
}
S = Parent;
}
assert(S && "Cannot have null Stmt for PathDiagnosticLocation");
// Special case: DeclStmts can appear in for statement declarations, in which
// case the ForStmt is the context.
if (isa<DeclStmt>(S)) {
if (const Stmt *Parent = P.getParent(S)) {
switch (Parent->getStmtClass()) {
case Stmt::ForStmtClass:
case Stmt::ObjCForCollectionStmtClass:
return PathDiagnosticLocation(Parent, SMgr, LC);
default:
break;
}
}
}
else if (isa<BinaryOperator>(S)) {
// Special case: the binary operator represents the initialization
// code in a for statement (this can happen when the variable being
// initialized is an old variable.
if (const ForStmt *FS =
dyn_cast_or_null<ForStmt>(P.getParentIgnoreParens(S))) {
if (FS->getInit() == S)
return PathDiagnosticLocation(FS, SMgr, LC);
}
}
return PathDiagnosticLocation(S, SMgr, LC);
}
//===----------------------------------------------------------------------===//
// ScanNotableSymbols: closure-like callback for scanning Store bindings.
//===----------------------------------------------------------------------===//
static const VarDecl* GetMostRecentVarDeclBinding(const ExplodedNode *N,
ProgramStateManager& VMgr,
SVal X) {
for ( ; N ; N = N->pred_empty() ? 0 : *N->pred_begin()) {
ProgramPoint P = N->getLocation();
if (!isa<PostStmt>(P))
continue;
const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(cast<PostStmt>(P).getStmt());
if (!DR)
continue;
SVal Y = N->getState()->getSVal(DR, N->getLocationContext());
if (X != Y)
continue;
const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
if (!VD)
continue;
return VD;
}
return 0;
}
namespace {
class NotableSymbolHandler
: public StoreManager::BindingsHandler {
SymbolRef Sym;
ProgramStateRef PrevSt;
const Stmt *S;
ProgramStateManager& VMgr;
const ExplodedNode *Pred;
PathDiagnostic& PD;
BugReporter& BR;
public:
NotableSymbolHandler(SymbolRef sym,
ProgramStateRef prevst,
const Stmt *s,
ProgramStateManager& vmgr,
const ExplodedNode *pred,
PathDiagnostic& pd,
BugReporter& br)
: Sym(sym),
PrevSt(prevst),
S(s),
VMgr(vmgr),
Pred(pred),
PD(pd),
BR(br) {}
bool HandleBinding(StoreManager& SMgr, Store store, const MemRegion* R,
SVal V) {
SymbolRef ScanSym = V.getAsSymbol();
if (ScanSym != Sym)
return true;
// Check if the previous state has this binding.
SVal X = PrevSt->getSVal(loc::MemRegionVal(R));
if (X == V) // Same binding?
return true;
// Different binding. Only handle assignments for now. We don't pull
// this check out of the loop because we will eventually handle other
// cases.
VarDecl *VD = 0;
if (const BinaryOperator* B = dyn_cast<BinaryOperator>(S)) {
if (!B->isAssignmentOp())
return true;
// What variable did we assign to?
DeclRefExpr *DR = dyn_cast<DeclRefExpr>(B->getLHS()->IgnoreParenCasts());
if (!DR)
return true;
VD = dyn_cast<VarDecl>(DR->getDecl());
}
else if (const DeclStmt *DS = dyn_cast<DeclStmt>(S)) {
// FIXME: Eventually CFGs won't have DeclStmts. Right now we
// assume that each DeclStmt has a single Decl. This invariant
// holds by construction in the CFG.
VD = dyn_cast<VarDecl>(*DS->decl_begin());
}
if (!VD)
return true;
// What is the most recently referenced variable with this binding?
const VarDecl *MostRecent = GetMostRecentVarDeclBinding(Pred, VMgr, V);
if (!MostRecent)
return true;
// Create the diagnostic.
if (Loc::isLocType(VD->getType())) {
SmallString<64> buf;
llvm::raw_svector_ostream os(buf);
os << '\'' << *VD << "' now aliases '" << *MostRecent << '\'';
PathDiagnosticLocation L =
PathDiagnosticLocation::createBegin(S, BR.getSourceManager(),
Pred->getLocationContext());
PD.getActivePath().push_front(new PathDiagnosticEventPiece(L, os.str()));
}
return true;
}
};
}
static void HandleNotableSymbol(const ExplodedNode *N,
const Stmt *S,
SymbolRef Sym, BugReporter& BR,
PathDiagnostic& PD) {
const ExplodedNode *Pred = N->pred_empty() ? 0 : *N->pred_begin();
ProgramStateRef PrevSt = Pred ? Pred->getState() : 0;
if (!PrevSt)
return;
// Look at the region bindings of the current state that map to the
// specified symbol. Are any of them not in the previous state?
ProgramStateManager& VMgr = cast<GRBugReporter>(BR).getStateManager();
NotableSymbolHandler H(Sym, PrevSt, S, VMgr, Pred, PD, BR);
cast<GRBugReporter>(BR).getStateManager().iterBindings(N->getState(), H);
}
namespace {
class ScanNotableSymbols
: public StoreManager::BindingsHandler {
llvm::SmallSet<SymbolRef, 10> AlreadyProcessed;
const ExplodedNode *N;
const Stmt *S;
GRBugReporter& BR;
PathDiagnostic& PD;
public:
ScanNotableSymbols(const ExplodedNode *n, const Stmt *s,
GRBugReporter& br, PathDiagnostic& pd)
: N(n), S(s), BR(br), PD(pd) {}
bool HandleBinding(StoreManager& SMgr, Store store,
const MemRegion* R, SVal V) {
SymbolRef ScanSym = V.getAsSymbol();
if (!ScanSym)
return true;
if (!BR.isNotable(ScanSym))
return true;
if (AlreadyProcessed.count(ScanSym))
return true;
AlreadyProcessed.insert(ScanSym);
HandleNotableSymbol(N, S, ScanSym, BR, PD);
return true;
}
};
} // end anonymous namespace
//===----------------------------------------------------------------------===//
// "Minimal" path diagnostic generation algorithm.
//===----------------------------------------------------------------------===//
static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM);
static void GenerateMinimalPathDiagnostic(PathDiagnostic& PD,
PathDiagnosticBuilder &PDB,
const ExplodedNode *N) {
SourceManager& SMgr = PDB.getSourceManager();
const LocationContext *LC = PDB.LC;
const ExplodedNode *NextNode = N->pred_empty()
? NULL : *(N->pred_begin());
while (NextNode) {
N = NextNode;
PDB.LC = N->getLocationContext();
NextNode = GetPredecessorNode(N);
ProgramPoint P = N->getLocation();
if (const CallExit *CE = dyn_cast<CallExit>(&P)) {
PathDiagnosticCallPiece *C =
PathDiagnosticCallPiece::construct(N, *CE, SMgr);
PD.getActivePath().push_front(C);
PD.pushActivePath(&C->path);
continue;
}
if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) {
PD.popActivePath();
// The current active path should never be empty. Either we
// just added a bunch of stuff to the top-level path, or
// we have a previous CallExit. If the front of the active
// path is not a PathDiagnosticCallPiece, it means that the
// path terminated within a function call. We must then take the
// current contents of the active path and place it within
// a new PathDiagnosticCallPiece.
assert(!PD.getActivePath().empty());
PathDiagnosticCallPiece *C =
dyn_cast<PathDiagnosticCallPiece>(PD.getActivePath().front());
if (!C)
C = PathDiagnosticCallPiece::construct(PD.getActivePath());
C->setCallee(*CE, SMgr);
continue;
}
if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
const CFGBlock *Src = BE->getSrc();
const CFGBlock *Dst = BE->getDst();
const Stmt *T = Src->getTerminator();
if (!T)
continue;
PathDiagnosticLocation Start =
PathDiagnosticLocation::createBegin(T, SMgr,
N->getLocationContext());
switch (T->getStmtClass()) {
default:
break;
case Stmt::GotoStmtClass:
case Stmt::IndirectGotoStmtClass: {
const Stmt *S = GetNextStmt(N);
if (!S)
continue;
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S);
os << "Control jumps to line "
<< End.asLocation().getExpansionLineNumber();
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
break;
}
case Stmt::SwitchStmtClass: {
// Figure out what case arm we took.
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
if (const Stmt *S = Dst->getLabel()) {
PathDiagnosticLocation End(S, SMgr, LC);
switch (S->getStmtClass()) {
default:
os << "No cases match in the switch statement. "
"Control jumps to line "
<< End.asLocation().getExpansionLineNumber();
break;
case Stmt::DefaultStmtClass:
os << "Control jumps to the 'default' case at line "
<< End.asLocation().getExpansionLineNumber();
break;
case Stmt::CaseStmtClass: {
os << "Control jumps to 'case ";
const CaseStmt *Case = cast<CaseStmt>(S);
const Expr *LHS = Case->getLHS()->IgnoreParenCasts();
// Determine if it is an enum.
bool GetRawInt = true;
if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(LHS)) {
// FIXME: Maybe this should be an assertion. Are there cases
// were it is not an EnumConstantDecl?
const EnumConstantDecl *D =
dyn_cast<EnumConstantDecl>(DR->getDecl());
if (D) {
GetRawInt = false;
os << *D;
}
}
if (GetRawInt)
os << LHS->EvaluateKnownConstInt(PDB.getASTContext());
os << ":' at line "
<< End.asLocation().getExpansionLineNumber();
break;
}
}
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
}
else {
os << "'Default' branch taken. ";
const PathDiagnosticLocation &End = PDB.ExecutionContinues(os, N);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
}
break;
}
case Stmt::BreakStmtClass:
case Stmt::ContinueStmtClass: {
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
break;
}
// Determine control-flow for ternary '?'.
case Stmt::BinaryConditionalOperatorClass:
case Stmt::ConditionalOperatorClass: {
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
os << "'?' condition is ";
if (*(Src->succ_begin()+1) == Dst)
os << "false";
else
os << "true";
PathDiagnosticLocation End = PDB.ExecutionContinues(N);
if (const Stmt *S = End.asStmt())
End = PDB.getEnclosingStmtLocation(S);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
break;
}
// Determine control-flow for short-circuited '&&' and '||'.
case Stmt::BinaryOperatorClass: {
if (!PDB.supportsLogicalOpControlFlow())
break;
const BinaryOperator *B = cast<BinaryOperator>(T);
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
os << "Left side of '";
if (B->getOpcode() == BO_LAnd) {
os << "&&" << "' is ";
if (*(Src->succ_begin()+1) == Dst) {
os << "false";
PathDiagnosticLocation End(B->getLHS(), SMgr, LC);
PathDiagnosticLocation Start =
PathDiagnosticLocation::createOperatorLoc(B, SMgr);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
}
else {
os << "true";
PathDiagnosticLocation Start(B->getLHS(), SMgr, LC);
PathDiagnosticLocation End = PDB.ExecutionContinues(N);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
}
}
else {
assert(B->getOpcode() == BO_LOr);
os << "||" << "' is ";
if (*(Src->succ_begin()+1) == Dst) {
os << "false";
PathDiagnosticLocation Start(B->getLHS(), SMgr, LC);
PathDiagnosticLocation End = PDB.ExecutionContinues(N);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
}
else {
os << "true";
PathDiagnosticLocation End(B->getLHS(), SMgr, LC);
PathDiagnosticLocation Start =
PathDiagnosticLocation::createOperatorLoc(B, SMgr);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
}
}
break;
}
case Stmt::DoStmtClass: {
if (*(Src->succ_begin()) == Dst) {
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
os << "Loop condition is true. ";
PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
if (const Stmt *S = End.asStmt())
End = PDB.getEnclosingStmtLocation(S);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
}
else {
PathDiagnosticLocation End = PDB.ExecutionContinues(N);
if (const Stmt *S = End.asStmt())
End = PDB.getEnclosingStmtLocation(S);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
"Loop condition is false. Exiting loop"));
}
break;
}
case Stmt::WhileStmtClass:
case Stmt::ForStmtClass: {
if (*(Src->succ_begin()+1) == Dst) {
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
os << "Loop condition is false. ";
PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
if (const Stmt *S = End.asStmt())
End = PDB.getEnclosingStmtLocation(S);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
os.str()));
}
else {
PathDiagnosticLocation End = PDB.ExecutionContinues(N);
if (const Stmt *S = End.asStmt())
End = PDB.getEnclosingStmtLocation(S);
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
"Loop condition is true. Entering loop body"));
}
break;
}
case Stmt::IfStmtClass: {
PathDiagnosticLocation End = PDB.ExecutionContinues(N);
if (const Stmt *S = End.asStmt())
End = PDB.getEnclosingStmtLocation(S);
if (*(Src->succ_begin()+1) == Dst)
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
"Taking false branch"));
else
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
"Taking true branch"));
break;
}
}
}
if (NextNode) {
// Add diagnostic pieces from custom visitors.
BugReport *R = PDB.getBugReport();
for (BugReport::visitor_iterator I = R->visitor_begin(),
E = R->visitor_end(); I!=E; ++I) {
if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R))
PD.getActivePath().push_front(p);
}
}
if (const PostStmt *PS = dyn_cast<PostStmt>(&P)) {
// Scan the region bindings, and see if a "notable" symbol has a new
// lval binding.
ScanNotableSymbols SNS(N, PS->getStmt(), PDB.getBugReporter(), PD);
PDB.getStateManager().iterBindings(N->getState(), SNS);
}
}
// After constructing the full PathDiagnostic, do a pass over it to compact
// PathDiagnosticPieces that occur within a macro.
CompactPathDiagnostic(PD.getMutablePieces(), PDB.getSourceManager());
}
//===----------------------------------------------------------------------===//
// "Extensive" PathDiagnostic generation.
//===----------------------------------------------------------------------===//
static bool IsControlFlowExpr(const Stmt *S) {
const Expr *E = dyn_cast<Expr>(S);
if (!E)
return false;
E = E->IgnoreParenCasts();
if (isa<AbstractConditionalOperator>(E))
return true;
if (const BinaryOperator *B = dyn_cast<BinaryOperator>(E))
if (B->isLogicalOp())
return true;
return false;
}
namespace {
class ContextLocation : public PathDiagnosticLocation {
bool IsDead;
public:
ContextLocation(const PathDiagnosticLocation &L, bool isdead = false)
: PathDiagnosticLocation(L), IsDead(isdead) {}
void markDead() { IsDead = true; }
bool isDead() const { return IsDead; }
};
class EdgeBuilder {
std::vector<ContextLocation> CLocs;
typedef std::vector<ContextLocation>::iterator iterator;
PathDiagnostic &PD;
PathDiagnosticBuilder &PDB;
PathDiagnosticLocation PrevLoc;
bool IsConsumedExpr(const PathDiagnosticLocation &L);
bool containsLocation(const PathDiagnosticLocation &Container,
const PathDiagnosticLocation &Containee);
PathDiagnosticLocation getContextLocation(const PathDiagnosticLocation &L);
PathDiagnosticLocation cleanUpLocation(PathDiagnosticLocation L,
bool firstCharOnly = false) {
if (const Stmt *S = L.asStmt()) {
const Stmt *Original = S;
while (1) {
// Adjust the location for some expressions that are best referenced
// by one of their subexpressions.
switch (S->getStmtClass()) {
default:
break;
case Stmt::ParenExprClass:
case Stmt::GenericSelectionExprClass:
S = cast<Expr>(S)->IgnoreParens();
firstCharOnly = true;
continue;
case Stmt::BinaryConditionalOperatorClass:
case Stmt::ConditionalOperatorClass:
S = cast<AbstractConditionalOperator>(S)->getCond();
firstCharOnly = true;
continue;
case Stmt::ChooseExprClass:
S = cast<ChooseExpr>(S)->getCond();
firstCharOnly = true;
continue;
case Stmt::BinaryOperatorClass:
S = cast<BinaryOperator>(S)->getLHS();
firstCharOnly = true;
continue;
}
break;
}
if (S != Original)
L = PathDiagnosticLocation(S, L.getManager(), PDB.LC);
}
if (firstCharOnly)
L = PathDiagnosticLocation::createSingleLocation(L);
return L;
}
void popLocation() {
if (!CLocs.back().isDead() && CLocs.back().asLocation().isFileID()) {
// For contexts, we only one the first character as the range.
rawAddEdge(cleanUpLocation(CLocs.back(), true));
}
CLocs.pop_back();
}
public:
EdgeBuilder(PathDiagnostic &pd, PathDiagnosticBuilder &pdb)
: PD(pd), PDB(pdb) {
// If the PathDiagnostic already has pieces, add the enclosing statement
// of the first piece as a context as well.
if (!PD.path.empty()) {
PrevLoc = (*PD.path.begin())->getLocation();
if (const Stmt *S = PrevLoc.asStmt())
addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt());
}
}
~EdgeBuilder() {
while (!CLocs.empty()) popLocation();
// Finally, add an initial edge from the start location of the first
// statement (if it doesn't already exist).
PathDiagnosticLocation L = PathDiagnosticLocation::createDeclBegin(
PDB.LC,
PDB.getSourceManager());
if (L.isValid())
rawAddEdge(L);
}
void flushLocations() {
while (!CLocs.empty())
popLocation();
PrevLoc = PathDiagnosticLocation();
}
void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false);
void rawAddEdge(PathDiagnosticLocation NewLoc);
void addContext(const Stmt *S);
void addExtendedContext(const Stmt *S);
};
} // end anonymous namespace
PathDiagnosticLocation
EdgeBuilder::getContextLocation(const PathDiagnosticLocation &L) {
if (const Stmt *S = L.asStmt()) {
if (IsControlFlowExpr(S))
return L;
return PDB.getEnclosingStmtLocation(S);
}
return L;
}
bool EdgeBuilder::containsLocation(const PathDiagnosticLocation &Container,
const PathDiagnosticLocation &Containee) {
if (Container == Containee)
return true;
if (Container.asDecl())
return true;
if (const Stmt *S = Containee.asStmt())
if (const Stmt *ContainerS = Container.asStmt()) {
while (S) {
if (S == ContainerS)
return true;
S = PDB.getParent(S);
}
return false;
}
// Less accurate: compare using source ranges.
SourceRange ContainerR = Container.asRange();
SourceRange ContaineeR = Containee.asRange();
SourceManager &SM = PDB.getSourceManager();
SourceLocation ContainerRBeg = SM.getExpansionLoc(ContainerR.getBegin());
SourceLocation ContainerREnd = SM.getExpansionLoc(ContainerR.getEnd());
SourceLocation ContaineeRBeg = SM.getExpansionLoc(ContaineeR.getBegin());
SourceLocation ContaineeREnd = SM.getExpansionLoc(ContaineeR.getEnd());
unsigned ContainerBegLine = SM.getExpansionLineNumber(ContainerRBeg);
unsigned ContainerEndLine = SM.getExpansionLineNumber(ContainerREnd);
unsigned ContaineeBegLine = SM.getExpansionLineNumber(ContaineeRBeg);
unsigned ContaineeEndLine = SM.getExpansionLineNumber(ContaineeREnd);
assert(ContainerBegLine <= ContainerEndLine);
assert(ContaineeBegLine <= ContaineeEndLine);
return (ContainerBegLine <= ContaineeBegLine &&
ContainerEndLine >= ContaineeEndLine &&
(ContainerBegLine != ContaineeBegLine ||
SM.getExpansionColumnNumber(ContainerRBeg) <=
SM.getExpansionColumnNumber(ContaineeRBeg)) &&
(ContainerEndLine != ContaineeEndLine ||
SM.getExpansionColumnNumber(ContainerREnd) >=
SM.getExpansionColumnNumber(ContainerREnd)));
}
void EdgeBuilder::rawAddEdge(PathDiagnosticLocation NewLoc) {
if (!PrevLoc.isValid()) {
PrevLoc = NewLoc;
return;
}
const PathDiagnosticLocation &NewLocClean = cleanUpLocation(NewLoc);
const PathDiagnosticLocation &PrevLocClean = cleanUpLocation(PrevLoc);
if (NewLocClean.asLocation() == PrevLocClean.asLocation())
return;
// FIXME: Ignore intra-macro edges for now.
if (NewLocClean.asLocation().getExpansionLoc() ==
PrevLocClean.asLocation().getExpansionLoc())
return;
PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(NewLocClean, PrevLocClean));
PrevLoc = NewLoc;
}
void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd) {
if (!alwaysAdd && NewLoc.asLocation().isMacroID())
return;
const PathDiagnosticLocation &CLoc = getContextLocation(NewLoc);
while (!CLocs.empty()) {
ContextLocation &TopContextLoc = CLocs.back();
// Is the top location context the same as the one for the new location?
if (TopContextLoc == CLoc) {
if (alwaysAdd) {
if (IsConsumedExpr(TopContextLoc) &&
!IsControlFlowExpr(TopContextLoc.asStmt()))
TopContextLoc.markDead();
rawAddEdge(NewLoc);
}
return;
}
if (containsLocation(TopContextLoc, CLoc)) {
if (alwaysAdd) {
rawAddEdge(NewLoc);
if (IsConsumedExpr(CLoc) && !IsControlFlowExpr(CLoc.asStmt())) {
CLocs.push_back(ContextLocation(CLoc, true));
return;
}
}
CLocs.push_back(CLoc);
return;
}
// Context does not contain the location. Flush it.
popLocation();
}
// If we reach here, there is no enclosing context. Just add the edge.
rawAddEdge(NewLoc);
}
bool EdgeBuilder::IsConsumedExpr(const PathDiagnosticLocation &L) {
if (const Expr *X = dyn_cast_or_null<Expr>(L.asStmt()))
return PDB.getParentMap().isConsumedExpr(X) && !IsControlFlowExpr(X);
return false;
}
void EdgeBuilder::addExtendedContext(const Stmt *S) {
if (!S)
return;
const Stmt *Parent = PDB.getParent(S);
while (Parent) {
if (isa<CompoundStmt>(Parent))
Parent = PDB.getParent(Parent);
else
break;
}
if (Parent) {
switch (Parent->getStmtClass()) {
case Stmt::DoStmtClass:
case Stmt::ObjCAtSynchronizedStmtClass:
addContext(Parent);
default:
break;
}
}
addContext(S);
}
void EdgeBuilder::addContext(const Stmt *S) {
if (!S)
return;
PathDiagnosticLocation L(S, PDB.getSourceManager(), PDB.LC);
while (!CLocs.empty()) {
const PathDiagnosticLocation &TopContextLoc = CLocs.back();
// Is the top location context the same as the one for the new location?
if (TopContextLoc == L)
return;
if (containsLocation(TopContextLoc, L)) {
CLocs.push_back(L);
return;
}
// Context does not contain the location. Flush it.
popLocation();
}
CLocs.push_back(L);
}
static void GenerateExtensivePathDiagnostic(PathDiagnostic& PD,
PathDiagnosticBuilder &PDB,
const ExplodedNode *N) {
EdgeBuilder EB(PD, PDB);
const SourceManager& SM = PDB.getSourceManager();
const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin());
while (NextNode) {
N = NextNode;
NextNode = GetPredecessorNode(N);
ProgramPoint P = N->getLocation();
do {
if (const CallExit *CE = dyn_cast<CallExit>(&P)) {
const StackFrameContext *LCtx =
CE->getLocationContext()->getCurrentStackFrame();
PathDiagnosticLocation Loc(LCtx->getCallSite(),
PDB.getSourceManager(),
LCtx);
EB.addEdge(Loc, true);
EB.flushLocations();
PathDiagnosticCallPiece *C =
PathDiagnosticCallPiece::construct(N, *CE, SM);
PD.getActivePath().push_front(C);
PD.pushActivePath(&C->path);
break;
}
// Note that is important that we update the LocationContext
// after looking at CallExits. CallExit basically adds an
// edge in the *caller*, so we don't want to update the LocationContext
// too soon.
PDB.LC = N->getLocationContext();
// Pop the call hierarchy if we are done walking the contents
// of a function call.
if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) {
PD.popActivePath();
// The current active path should never be empty. Either we
// just added a bunch of stuff to the top-level path, or
// we have a previous CallExit. If the front of the active
// path is not a PathDiagnosticCallPiece, it means that the
// path terminated within a function call. We must then take the
// current contents of the active path and place it within
// a new PathDiagnosticCallPiece.
assert(!PD.getActivePath().empty());
PathDiagnosticCallPiece *C =
dyn_cast<PathDiagnosticCallPiece>(PD.getActivePath().front());
if (!C)
C = PathDiagnosticCallPiece::construct(PD.getActivePath());
C->setCallee(*CE, SM);
EB.flushLocations();
EB.addContext(CE->getCallExpr());
break;
}
// Block edges.
if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
const CFGBlock &Blk = *BE->getSrc();
const Stmt *Term = Blk.getTerminator();
// Are we jumping to the head of a loop? Add a special diagnostic.
if (const Stmt *Loop = BE->getDst()->getLoopTarget()) {
PathDiagnosticLocation L(Loop, SM, PDB.LC);
const CompoundStmt *CS = NULL;
if (!Term) {
if (const ForStmt *FS = dyn_cast<ForStmt>(Loop))
CS = dyn_cast<CompoundStmt>(FS->getBody());
else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop))
CS = dyn_cast<CompoundStmt>(WS->getBody());
}
PathDiagnosticEventPiece *p =
new PathDiagnosticEventPiece(L,
"Looping back to the head of the loop");
EB.addEdge(p->getLocation(), true);
PD.getActivePath().push_front(p);
if (CS) {
PathDiagnosticLocation BL =
PathDiagnosticLocation::createEndBrace(CS, SM);
EB.addEdge(BL);
}
}
if (Term)
EB.addContext(Term);
break;
}
if (const BlockEntrance *BE = dyn_cast<BlockEntrance>(&P)) {
if (const CFGStmt *S = BE->getFirstElement().getAs<CFGStmt>()) {
const Stmt *stmt = S->getStmt();
if (IsControlFlowExpr(stmt)) {
// Add the proper context for '&&', '||', and '?'.
EB.addContext(stmt);
}
else
EB.addExtendedContext(PDB.getEnclosingStmtLocation(stmt).asStmt());
}
break;
}
} while (0);
if (!NextNode)
continue;
// Add pieces from custom visitors.
BugReport *R = PDB.getBugReport();
for (BugReport::visitor_iterator I = R->visitor_begin(),
E = R->visitor_end(); I!=E; ++I) {
if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) {
const PathDiagnosticLocation &Loc = p->getLocation();
EB.addEdge(Loc, true);
PD.getActivePath().push_front(p);
if (const Stmt *S = Loc.asStmt())
EB.addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt());
}
}
}
}
//===----------------------------------------------------------------------===//
// Methods for BugType and subclasses.
//===----------------------------------------------------------------------===//
BugType::~BugType() { }
void BugType::FlushReports(BugReporter &BR) {}
void BuiltinBug::anchor() {}
//===----------------------------------------------------------------------===//
// Methods for BugReport and subclasses.
//===----------------------------------------------------------------------===//
void BugReport::NodeResolver::anchor() {}
void BugReport::addVisitor(BugReporterVisitor* visitor) {
if (!visitor)
return;
llvm::FoldingSetNodeID ID;
visitor->Profile(ID);
void *InsertPos;
if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) {
delete visitor;
return;
}
CallbacksSet.InsertNode(visitor, InsertPos);
Callbacks = F.add(visitor, Callbacks);
}
BugReport::~BugReport() {
for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) {
delete *I;
}
}
void BugReport::Profile(llvm::FoldingSetNodeID& hash) const {
hash.AddPointer(&BT);
hash.AddString(Description);
if (UniqueingLocation.isValid()) {
UniqueingLocation.Profile(hash);
} else if (Location.isValid()) {
Location.Profile(hash);
} else {
assert(ErrorNode);
hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode));
}
for (SmallVectorImpl<SourceRange>::const_iterator I =
Ranges.begin(), E = Ranges.end(); I != E; ++I) {
const SourceRange range = *I;
if (!range.isValid())
continue;
hash.AddInteger(range.getBegin().getRawEncoding());
hash.AddInteger(range.getEnd().getRawEncoding());
}
}
const Stmt *BugReport::getStmt() const {
if (!ErrorNode)
return 0;
ProgramPoint ProgP = ErrorNode->getLocation();
const Stmt *S = NULL;
if (BlockEntrance *BE = dyn_cast<BlockEntrance>(&ProgP)) {
CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit();
if (BE->getBlock() == &Exit)
S = GetPreviousStmt(ErrorNode);
}
if (!S)
S = GetStmt(ProgP);
return S;
}
std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator>
BugReport::getRanges() {
// If no custom ranges, add the range of the statement corresponding to
// the error node.
if (Ranges.empty()) {
if (const Expr *E = dyn_cast_or_null<Expr>(getStmt()))
addRange(E->getSourceRange());
else
return std::make_pair(ranges_iterator(), ranges_iterator());
}
// User-specified absence of range info.
if (Ranges.size() == 1 && !Ranges.begin()->isValid())
return std::make_pair(ranges_iterator(), ranges_iterator());
return std::make_pair(Ranges.begin(), Ranges.end());
}
PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const {
if (ErrorNode) {
assert(!Location.isValid() &&
"Either Location or ErrorNode should be specified but not both.");
if (const Stmt *S = GetCurrentOrPreviousStmt(ErrorNode)) {
const LocationContext *LC = ErrorNode->getLocationContext();
// For member expressions, return the location of the '.' or '->'.
if (const MemberExpr *ME = dyn_cast<MemberExpr>(S))
return PathDiagnosticLocation::createMemberLoc(ME, SM);
// For binary operators, return the location of the operator.
if (const BinaryOperator *B = dyn_cast<BinaryOperator>(S))
return PathDiagnosticLocation::createOperatorLoc(B, SM);
return PathDiagnosticLocation::createBegin(S, SM, LC);
}
} else {
assert(Location.isValid());
return Location;
}
return PathDiagnosticLocation();
}
//===----------------------------------------------------------------------===//
// Methods for BugReporter and subclasses.
//===----------------------------------------------------------------------===//
BugReportEquivClass::~BugReportEquivClass() {
for (iterator I=begin(), E=end(); I!=E; ++I) delete *I;
}
GRBugReporter::~GRBugReporter() { }
BugReporterData::~BugReporterData() {}
ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); }
ProgramStateManager&
GRBugReporter::getStateManager() { return Eng.getStateManager(); }
BugReporter::~BugReporter() {
FlushReports();
// Free the bug reports we are tracking.
typedef std::vector<BugReportEquivClass *> ContTy;
for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end();
I != E; ++I) {
delete *I;
}
}
void BugReporter::FlushReports() {
if (BugTypes.isEmpty())
return;
// First flush the warnings for each BugType. This may end up creating new
// warnings and new BugTypes.
// FIXME: Only NSErrorChecker needs BugType's FlushReports.
// Turn NSErrorChecker into a proper checker and remove this.
SmallVector<const BugType*, 16> bugTypes;
for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I)
bugTypes.push_back(*I);
for (SmallVector<const BugType*, 16>::iterator
I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I)
const_cast<BugType*>(*I)->FlushReports(*this);
typedef llvm::FoldingSet<BugReportEquivClass> SetTy;
for (SetTy::iterator EI=EQClasses.begin(), EE=EQClasses.end(); EI!=EE;++EI){
BugReportEquivClass& EQ = *EI;
FlushReport(EQ);
}
// BugReporter owns and deletes only BugTypes created implicitly through
// EmitBasicReport.
// FIXME: There are leaks from checkers that assume that the BugTypes they
// create will be destroyed by the BugReporter.
for (llvm::StringMap<BugType*>::iterator
I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I)
delete I->second;
// Remove all references to the BugType objects.
BugTypes = F.getEmptySet();
}
//===----------------------------------------------------------------------===//
// PathDiagnostics generation.
//===----------------------------------------------------------------------===//
static std::pair<std::pair<ExplodedGraph*, NodeBackMap*>,
std::pair<ExplodedNode*, unsigned> >
MakeReportGraph(const ExplodedGraph* G,
SmallVectorImpl<const ExplodedNode*> &nodes) {
// Create the trimmed graph. It will contain the shortest paths from the
// error nodes to the root. In the new graph we should only have one
// error node unless there are two or more error nodes with the same minimum
// path length.
ExplodedGraph* GTrim;
InterExplodedGraphMap* NMap;
llvm::DenseMap<const void*, const void*> InverseMap;
llvm::tie(GTrim, NMap) = G->Trim(nodes.data(), nodes.data() + nodes.size(),
&InverseMap);
// Create owning pointers for GTrim and NMap just to ensure that they are
// released when this function exists.
OwningPtr<ExplodedGraph> AutoReleaseGTrim(GTrim);
OwningPtr<InterExplodedGraphMap> AutoReleaseNMap(NMap);
// Find the (first) error node in the trimmed graph. We just need to consult
// the node map (NMap) which maps from nodes in the original graph to nodes
// in the new graph.
std::queue<const ExplodedNode*> WS;
typedef llvm::DenseMap<const ExplodedNode*, unsigned> IndexMapTy;
IndexMapTy IndexMap;
for (unsigned nodeIndex = 0 ; nodeIndex < nodes.size(); ++nodeIndex) {
const ExplodedNode *originalNode = nodes[nodeIndex];
if (const ExplodedNode *N = NMap->getMappedNode(originalNode)) {
WS.push(N);
IndexMap[originalNode] = nodeIndex;
}
}
assert(!WS.empty() && "No error node found in the trimmed graph.");
// Create a new (third!) graph with a single path. This is the graph
// that will be returned to the caller.
ExplodedGraph *GNew = new ExplodedGraph();
// Sometimes the trimmed graph can contain a cycle. Perform a reverse BFS
// to the root node, and then construct a new graph that contains only
// a single path.
llvm::DenseMap<const void*,unsigned> Visited;
unsigned cnt = 0;
const ExplodedNode *Root = 0;
while (!WS.empty()) {
const ExplodedNode *Node = WS.front();
WS.pop();
if (Visited.find(Node) != Visited.end())
continue;
Visited[Node] = cnt++;
if (Node->pred_empty()) {
Root = Node;
break;
}
for (ExplodedNode::const_pred_iterator I=Node->pred_begin(),
E=Node->pred_end(); I!=E; ++I)
WS.push(*I);
}
assert(Root);
// Now walk from the root down the BFS path, always taking the successor
// with the lowest number.
ExplodedNode *Last = 0, *First = 0;
NodeBackMap *BM = new NodeBackMap();
unsigned NodeIndex = 0;
for ( const ExplodedNode *N = Root ;;) {
// Lookup the number associated with the current node.
llvm::DenseMap<const void*,unsigned>::iterator I = Visited.find(N);
assert(I != Visited.end());
// Create the equivalent node in the new graph with the same state
// and location.
ExplodedNode *NewN = GNew->getNode(N->getLocation(), N->getState());
// Store the mapping to the original node.
llvm::DenseMap<const void*, const void*>::iterator IMitr=InverseMap.find(N);
assert(IMitr != InverseMap.end() && "No mapping to original node.");
(*BM)[NewN] = (const ExplodedNode*) IMitr->second;
// Link up the new node with the previous node.
if (Last)
NewN->addPredecessor(Last, *GNew);
Last = NewN;
// Are we at the final node?
IndexMapTy::iterator IMI =
IndexMap.find((const ExplodedNode*)(IMitr->second));
if (IMI != IndexMap.end()) {
First = NewN;
NodeIndex = IMI->second;
break;
}
// Find the next successor node. We choose the node that is marked
// with the lowest DFS number.
ExplodedNode::const_succ_iterator SI = N->succ_begin();
ExplodedNode::const_succ_iterator SE = N->succ_end();
N = 0;
for (unsigned MinVal = 0; SI != SE; ++SI) {
I = Visited.find(*SI);
if (I == Visited.end())
continue;
if (!N || I->second < MinVal) {
N = *SI;
MinVal = I->second;
}
}
assert(N);
}
assert(First);
return std::make_pair(std::make_pair(GNew, BM),
std::make_pair(First, NodeIndex));
}
/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object
/// and collapses PathDiagosticPieces that are expanded by macros.
static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) {
typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>,
SourceLocation> > MacroStackTy;
typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> >
PiecesTy;
MacroStackTy MacroStack;
PiecesTy Pieces;
for (PathPieces::const_iterator I = path.begin(), E = path.end();
I!=E; ++I) {
PathDiagnosticPiece *piece = I->getPtr();
// Recursively compact calls.
if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){
CompactPathDiagnostic(call->path, SM);
}
// Get the location of the PathDiagnosticPiece.
const FullSourceLoc Loc = piece->getLocation().asLocation();
// Determine the instantiation location, which is the location we group
// related PathDiagnosticPieces.
SourceLocation InstantiationLoc = Loc.isMacroID() ?
SM.getExpansionLoc(Loc) :
SourceLocation();
if (Loc.isFileID()) {
MacroStack.clear();
Pieces.push_back(piece);
continue;
}
assert(Loc.isMacroID());
// Is the PathDiagnosticPiece within the same macro group?
if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) {
MacroStack.back().first->subPieces.push_back(piece);
continue;
}
// We aren't in the same group. Are we descending into a new macro
// or are part of an old one?
IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup;
SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ?
SM.getExpansionLoc(Loc) :
SourceLocation();
// Walk the entire macro stack.
while (!MacroStack.empty()) {
if (InstantiationLoc == MacroStack.back().second) {
MacroGroup = MacroStack.back().first;
break;
}
if (ParentInstantiationLoc == MacroStack.back().second) {
MacroGroup = MacroStack.back().first;
break;
}
MacroStack.pop_back();
}
if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) {
// Create a new macro group and add it to the stack.
PathDiagnosticMacroPiece *NewGroup =
new PathDiagnosticMacroPiece(
PathDiagnosticLocation::createSingleLocation(piece->getLocation()));
if (MacroGroup)
MacroGroup->subPieces.push_back(NewGroup);
else {
assert(InstantiationLoc.isFileID());
Pieces.push_back(NewGroup);
}
MacroGroup = NewGroup;
MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc));
}
// Finally, add the PathDiagnosticPiece to the group.
MacroGroup->subPieces.push_back(piece);
}
// Now take the pieces and construct a new PathDiagnostic.
path.clear();
for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I)
path.push_back(*I);
}
void GRBugReporter::GeneratePathDiagnostic(PathDiagnostic& PD,
SmallVectorImpl<BugReport *> &bugReports) {
assert(!bugReports.empty());
SmallVector<const ExplodedNode *, 10> errorNodes;
for (SmallVectorImpl<BugReport*>::iterator I = bugReports.begin(),
E = bugReports.end(); I != E; ++I) {
errorNodes.push_back((*I)->getErrorNode());
}
// Construct a new graph that contains only a single path from the error
// node to a root.
const std::pair<std::pair<ExplodedGraph*, NodeBackMap*>,
std::pair<ExplodedNode*, unsigned> >&
GPair = MakeReportGraph(&getGraph(), errorNodes);
// Find the BugReport with the original location.
assert(GPair.second.second < bugReports.size());
BugReport *R = bugReports[GPair.second.second];
assert(R && "No original report found for sliced graph.");
OwningPtr<ExplodedGraph> ReportGraph(GPair.first.first);
OwningPtr<NodeBackMap> BackMap(GPair.first.second);
const ExplodedNode *N = GPair.second.first;
// Start building the path diagnostic...
PathDiagnosticBuilder PDB(*this, R, BackMap.get(),
getPathDiagnosticConsumer());
// Register additional node visitors.
R->addVisitor(new NilReceiverBRVisitor());
R->addVisitor(new ConditionBRVisitor());
// Generate the very last diagnostic piece - the piece is visible before
// the trace is expanded.
PathDiagnosticPiece *LastPiece = 0;
for (BugReport::visitor_iterator I = R->visitor_begin(),
E = R->visitor_end(); I!=E; ++I) {
if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) {
assert (!LastPiece &&
"There can only be one final piece in a diagnostic.");
LastPiece = Piece;
}
}
if (!LastPiece)
LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R);
if (LastPiece)
PD.getActivePath().push_back(LastPiece);
else
return;
switch (PDB.getGenerationScheme()) {
case PathDiagnosticConsumer::Extensive:
GenerateExtensivePathDiagnostic(PD, PDB, N);
break;
case PathDiagnosticConsumer::Minimal:
GenerateMinimalPathDiagnostic(PD, PDB, N);
break;
}
// Finally, prune the diagnostic path of uninteresting stuff.
bool hasSomethingInteresting = RemoveUneededCalls(PD.getMutablePieces());
assert(hasSomethingInteresting);
(void) hasSomethingInteresting;
}
void BugReporter::Register(BugType *BT) {
BugTypes = F.add(BugTypes, BT);
}
void BugReporter::EmitReport(BugReport* R) {
// Compute the bug report's hash to determine its equivalence class.
llvm::FoldingSetNodeID ID;
R->Profile(ID);
// Lookup the equivance class. If there isn't one, create it.
BugType& BT = R->getBugType();
Register(&BT);
void *InsertPos;
BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos);
if (!EQ) {
EQ = new BugReportEquivClass(R);
EQClasses.InsertNode(EQ, InsertPos);
EQClassesVector.push_back(EQ);
}
else
EQ->AddReport(R);
}
//===----------------------------------------------------------------------===//
// Emitting reports in equivalence classes.
//===----------------------------------------------------------------------===//
namespace {
struct FRIEC_WLItem {
const ExplodedNode *N;
ExplodedNode::const_succ_iterator I, E;
FRIEC_WLItem(const ExplodedNode *n)
: N(n), I(N->succ_begin()), E(N->succ_end()) {}
};
}
static BugReport *
FindReportInEquivalenceClass(BugReportEquivClass& EQ,
SmallVectorImpl<BugReport*> &bugReports) {
BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end();
assert(I != E);
BugReport *R = *I;
BugType& BT = R->getBugType();
// If we don't need to suppress any of the nodes because they are
// post-dominated by a sink, simply add all the nodes in the equivalence class
// to 'Nodes'. Any of the reports will serve as a "representative" report.
if (!BT.isSuppressOnSink()) {
for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) {
const ExplodedNode *N = I->getErrorNode();
if (N) {
R = *I;
bugReports.push_back(R);
}
}
return R;
}
// For bug reports that should be suppressed when all paths are post-dominated
// by a sink node, iterate through the reports in the equivalence class
// until we find one that isn't post-dominated (if one exists). We use a
// DFS traversal of the ExplodedGraph to find a non-sink node. We could write
// this as a recursive function, but we don't want to risk blowing out the
// stack for very long paths.
BugReport *exampleReport = 0;
for (; I != E; ++I) {
R = *I;
const ExplodedNode *errorNode = R->getErrorNode();
if (!errorNode)
continue;
if (errorNode->isSink()) {
llvm_unreachable(
"BugType::isSuppressSink() should not be 'true' for sink end nodes");
}
// No successors? By definition this nodes isn't post-dominated by a sink.
if (errorNode->succ_empty()) {
bugReports.push_back(R);
if (!exampleReport)
exampleReport = R;
continue;
}
// At this point we know that 'N' is not a sink and it has at least one
// successor. Use a DFS worklist to find a non-sink end-of-path node.
typedef FRIEC_WLItem WLItem;
typedef SmallVector<WLItem, 10> DFSWorkList;
llvm::DenseMap<const ExplodedNode *, unsigned> Visited;
DFSWorkList WL;
WL.push_back(errorNode);
Visited[errorNode] = 1;
while (!WL.empty()) {
WLItem &WI = WL.back();
assert(!WI.N->succ_empty());
for (; WI.I != WI.E; ++WI.I) {
const ExplodedNode *Succ = *WI.I;
// End-of-path node?
if (Succ->succ_empty()) {
// If we found an end-of-path node that is not a sink.
if (!Succ->isSink()) {
bugReports.push_back(R);
if (!exampleReport)
exampleReport = R;
WL.clear();
break;
}
// Found a sink? Continue on to the next successor.
continue;
}
// Mark the successor as visited. If it hasn't been explored,
// enqueue it to the DFS worklist.
unsigned &mark = Visited[Succ];
if (!mark) {
mark = 1;
WL.push_back(Succ);
break;
}
}
// The worklist may have been cleared at this point. First
// check if it is empty before checking the last item.
if (!WL.empty() && &WL.back() == &WI)
WL.pop_back();
}
}
// ExampleReport will be NULL if all the nodes in the equivalence class
// were post-dominated by sinks.
return exampleReport;
}
//===----------------------------------------------------------------------===//
// DiagnosticCache. This is a hack to cache analyzer diagnostics. It
// uses global state, which eventually should go elsewhere.
//===----------------------------------------------------------------------===//
namespace {
class DiagCacheItem : public llvm::FoldingSetNode {
llvm::FoldingSetNodeID ID;
public:
DiagCacheItem(BugReport *R, PathDiagnostic *PD) {
R->Profile(ID);
PD->Profile(ID);
}
void Profile(llvm::FoldingSetNodeID &id) {
id = ID;
}
llvm::FoldingSetNodeID &getID() { return ID; }
};
}
static bool IsCachedDiagnostic(BugReport *R, PathDiagnostic *PD) {
// FIXME: Eventually this diagnostic cache should reside in something
// like AnalysisManager instead of being a static variable. This is
// really unsafe in the long term.
typedef llvm::FoldingSet<DiagCacheItem> DiagnosticCache;
static DiagnosticCache DC;
void *InsertPos;
DiagCacheItem *Item = new DiagCacheItem(R, PD);
if (DC.FindNodeOrInsertPos(Item->getID(), InsertPos)) {
delete Item;
return true;
}
DC.InsertNode(Item, InsertPos);
return false;
}
void BugReporter::FlushReport(BugReportEquivClass& EQ) {
SmallVector<BugReport*, 10> bugReports;
BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports);
if (!exampleReport)
return;
PathDiagnosticConsumer* PD = getPathDiagnosticConsumer();
// FIXME: Make sure we use the 'R' for the path that was actually used.
// Probably doesn't make a difference in practice.
BugType& BT = exampleReport->getBugType();
OwningPtr<PathDiagnostic>
D(new PathDiagnostic(exampleReport->getBugType().getName(),
!PD || PD->useVerboseDescription()
? exampleReport->getDescription()
: exampleReport->getShortDescription(),
BT.getCategory()));
if (!bugReports.empty())
GeneratePathDiagnostic(*D.get(), bugReports);
if (IsCachedDiagnostic(exampleReport, D.get()))
return;
// Get the meta data.
const BugReport::ExtraTextList &Meta =
exampleReport->getExtraText();
for (BugReport::ExtraTextList::const_iterator i = Meta.begin(),
e = Meta.end(); i != e; ++i) {
D->addMeta(*i);
}
// Emit a summary diagnostic to the regular Diagnostics engine.
BugReport::ranges_iterator Beg, End;
llvm::tie(Beg, End) = exampleReport->getRanges();
DiagnosticsEngine &Diag = getDiagnostic();
// Search the description for '%', as that will be interpretted as a
// format character by FormatDiagnostics.
StringRef desc = exampleReport->getShortDescription();
unsigned ErrorDiag;
{
SmallString<512> TmpStr;
llvm::raw_svector_ostream Out(TmpStr);
for (StringRef::iterator I=desc.begin(), E=desc.end(); I!=E; ++I)
if (*I == '%')
Out << "%%";
else
Out << *I;
Out.flush();
ErrorDiag = Diag.getCustomDiagID(DiagnosticsEngine::Warning, TmpStr);
}
{
DiagnosticBuilder diagBuilder = Diag.Report(
exampleReport->getLocation(getSourceManager()).asLocation(), ErrorDiag);
for (BugReport::ranges_iterator I = Beg; I != End; ++I)
diagBuilder << *I;
}
// Emit a full diagnostic for the path if we have a PathDiagnosticConsumer.
if (!PD)
return;
if (D->path.empty()) {
PathDiagnosticPiece *piece = new PathDiagnosticEventPiece(
exampleReport->getLocation(getSourceManager()),
exampleReport->getDescription());
for ( ; Beg != End; ++Beg) piece->addRange(*Beg);
D->getActivePath().push_back(piece);
}
PD->HandlePathDiagnostic(D.take());
}
void BugReporter::EmitBasicReport(StringRef name, StringRef str,
PathDiagnosticLocation Loc,
SourceRange* RBeg, unsigned NumRanges) {
EmitBasicReport(name, "", str, Loc, RBeg, NumRanges);
}
void BugReporter::EmitBasicReport(StringRef name,
StringRef category,
StringRef str, PathDiagnosticLocation Loc,
SourceRange* RBeg, unsigned NumRanges) {
// 'BT' is owned by BugReporter.
BugType *BT = getBugTypeForName(name, category);
BugReport *R = new BugReport(*BT, str, Loc);
for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg);
EmitReport(R);
}
BugType *BugReporter::getBugTypeForName(StringRef name,
StringRef category) {
SmallString<136> fullDesc;
llvm::raw_svector_ostream(fullDesc) << name << ":" << category;
llvm::StringMapEntry<BugType *> &
entry = StrBugTypes.GetOrCreateValue(fullDesc);
BugType *BT = entry.getValue();
if (!BT) {
BT = new BugType(name, category);
entry.setValue(BT);
}
return BT;
}
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