minix/external/bsd/llvm/dist/clang/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp

243 lines
7.7 KiB
C++
Raw Normal View History

//=======- VirtualCallChecker.cpp --------------------------------*- 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 a checker that checks virtual function calls during
// construction or destruction of C++ objects.
//
//===----------------------------------------------------------------------===//
#include "ClangSACheckers.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
using namespace ento;
namespace {
class WalkAST : public StmtVisitor<WalkAST> {
BugReporter &BR;
AnalysisDeclContext *AC;
typedef const CallExpr * WorkListUnit;
typedef SmallVector<WorkListUnit, 20> DFSWorkList;
/// A vector representing the worklist which has a chain of CallExprs.
DFSWorkList WList;
// PreVisited : A CallExpr to this FunctionDecl is in the worklist, but the
// body has not been visited yet.
// PostVisited : A CallExpr to this FunctionDecl is in the worklist, and the
// body has been visited.
enum Kind { NotVisited,
PreVisited, /**< A CallExpr to this FunctionDecl is in the
worklist, but the body has not yet been
visited. */
PostVisited /**< A CallExpr to this FunctionDecl is in the
worklist, and the body has been visited. */
};
/// A DenseMap that records visited states of FunctionDecls.
llvm::DenseMap<const FunctionDecl *, Kind> VisitedFunctions;
/// The CallExpr whose body is currently being visited. This is used for
/// generating bug reports. This is null while visiting the body of a
/// constructor or destructor.
const CallExpr *visitingCallExpr;
public:
WalkAST(BugReporter &br, AnalysisDeclContext *ac)
: BR(br),
AC(ac),
visitingCallExpr(0) {}
bool hasWork() const { return !WList.empty(); }
/// This method adds a CallExpr to the worklist and marks the callee as
/// being PreVisited.
void Enqueue(WorkListUnit WLUnit) {
const FunctionDecl *FD = WLUnit->getDirectCallee();
if (!FD || !FD->getBody())
return;
Kind &K = VisitedFunctions[FD];
if (K != NotVisited)
return;
K = PreVisited;
WList.push_back(WLUnit);
}
/// This method returns an item from the worklist without removing it.
WorkListUnit Dequeue() {
assert(!WList.empty());
return WList.back();
}
void Execute() {
while (hasWork()) {
WorkListUnit WLUnit = Dequeue();
const FunctionDecl *FD = WLUnit->getDirectCallee();
assert(FD && FD->getBody());
if (VisitedFunctions[FD] == PreVisited) {
// If the callee is PreVisited, walk its body.
// Visit the body.
SaveAndRestore<const CallExpr *> SaveCall(visitingCallExpr, WLUnit);
Visit(FD->getBody());
// Mark the function as being PostVisited to indicate we have
// scanned the body.
VisitedFunctions[FD] = PostVisited;
continue;
}
// Otherwise, the callee is PostVisited.
// Remove it from the worklist.
assert(VisitedFunctions[FD] == PostVisited);
WList.pop_back();
}
}
// Stmt visitor methods.
void VisitCallExpr(CallExpr *CE);
void VisitCXXMemberCallExpr(CallExpr *CE);
void VisitStmt(Stmt *S) { VisitChildren(S); }
void VisitChildren(Stmt *S);
void ReportVirtualCall(const CallExpr *CE, bool isPure);
};
} // end anonymous namespace
//===----------------------------------------------------------------------===//
// AST walking.
//===----------------------------------------------------------------------===//
void WalkAST::VisitChildren(Stmt *S) {
for (Stmt::child_iterator I = S->child_begin(), E = S->child_end(); I!=E; ++I)
if (Stmt *child = *I)
Visit(child);
}
void WalkAST::VisitCallExpr(CallExpr *CE) {
VisitChildren(CE);
Enqueue(CE);
}
void WalkAST::VisitCXXMemberCallExpr(CallExpr *CE) {
VisitChildren(CE);
bool callIsNonVirtual = false;
// Several situations to elide for checking.
if (MemberExpr *CME = dyn_cast<MemberExpr>(CE->getCallee())) {
// If the member access is fully qualified (i.e., X::F), then treat
// this as a non-virtual call and do not warn.
if (CME->getQualifier())
callIsNonVirtual = true;
// Elide analyzing the call entirely if the base pointer is not 'this'.
if (Expr *base = CME->getBase()->IgnoreImpCasts())
if (!isa<CXXThisExpr>(base))
return;
}
// Get the callee.
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CE->getDirectCallee());
if (MD && MD->isVirtual() && !callIsNonVirtual)
ReportVirtualCall(CE, MD->isPure());
Enqueue(CE);
}
void WalkAST::ReportVirtualCall(const CallExpr *CE, bool isPure) {
SmallString<100> buf;
llvm::raw_svector_ostream os(buf);
os << "Call Path : ";
// Name of current visiting CallExpr.
os << *CE->getDirectCallee();
// Name of the CallExpr whose body is current walking.
if (visitingCallExpr)
os << " <-- " << *visitingCallExpr->getDirectCallee();
// Names of FunctionDecls in worklist with state PostVisited.
for (SmallVectorImpl<const CallExpr *>::iterator I = WList.end(),
E = WList.begin(); I != E; --I) {
const FunctionDecl *FD = (*(I-1))->getDirectCallee();
assert(FD);
if (VisitedFunctions[FD] == PostVisited)
os << " <-- " << *FD;
}
PathDiagnosticLocation CELoc =
PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
SourceRange R = CE->getCallee()->getSourceRange();
if (isPure) {
os << "\n" << "Call pure virtual functions during construction or "
<< "destruction may leads undefined behaviour";
BR.EmitBasicReport(AC->getDecl(),
"Call pure virtual function during construction or "
"Destruction",
"Cplusplus",
os.str(), CELoc, R);
return;
}
else {
os << "\n" << "Call virtual functions during construction or "
<< "destruction will never go to a more derived class";
BR.EmitBasicReport(AC->getDecl(),
"Call virtual function during construction or "
"Destruction",
"Cplusplus",
os.str(), CELoc, R);
return;
}
}
//===----------------------------------------------------------------------===//
// VirtualCallChecker
//===----------------------------------------------------------------------===//
namespace {
class VirtualCallChecker : public Checker<check::ASTDecl<CXXRecordDecl> > {
public:
void checkASTDecl(const CXXRecordDecl *RD, AnalysisManager& mgr,
BugReporter &BR) const {
WalkAST walker(BR, mgr.getAnalysisDeclContext(RD));
// Check the constructors.
for (CXXRecordDecl::ctor_iterator I = RD->ctor_begin(), E = RD->ctor_end();
I != E; ++I) {
if (!I->isCopyOrMoveConstructor())
if (Stmt *Body = I->getBody()) {
walker.Visit(Body);
walker.Execute();
}
}
// Check the destructor.
if (CXXDestructorDecl *DD = RD->getDestructor())
if (Stmt *Body = DD->getBody()) {
walker.Visit(Body);
walker.Execute();
}
}
};
}
void ento::registerVirtualCallChecker(CheckerManager &mgr) {
mgr.registerChecker<VirtualCallChecker>();
}