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//==- CheckObjCDealloc.cpp - Check ObjC -dealloc implementation --*- 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 CheckObjCDealloc, a checker that
// analyzes an Objective-C class's implementation to determine if it
// correctly implements -dealloc.
//
//===----------------------------------------------------------------------===//
#include "clang/Analysis/LocalCheckers.h"
#include "clang/Analysis/PathDiagnostic.h"
#include "clang/Analysis/PathSensitive/BugReporter.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/Expr.h"
#include "clang/AST/DeclObjC.h"
#include "clang/Basic/LangOptions.h"
#include <sstream>
using namespace clang;
static bool scan_dealloc(Stmt* S, Selector Dealloc) {
if (ObjCMessageExpr* ME = dyn_cast<ObjCMessageExpr>(S))
if (ME->getSelector() == Dealloc)
if (Expr* Receiver = ME->getReceiver()->IgnoreParenCasts())
if (PreDefinedExpr* E = dyn_cast<PreDefinedExpr>(Receiver))
if (E->getIdentType() == PreDefinedExpr::ObjCSuper)
return true;
// Recurse to children.
for (Stmt::child_iterator I = S->child_begin(), E= S->child_end(); I!=E; ++I)
if (*I && scan_dealloc(*I, Dealloc))
return true;
return false;
}
static bool isSEL(QualType T, IdentifierInfo* SelII) {
if (const TypedefType* Ty = T->getAsTypedefType())
return Ty->getDecl()->getIdentifier() == SelII;
return false;
}
void clang::CheckObjCDealloc(ObjCImplementationDecl* D,
const LangOptions& LOpts, BugReporter& BR) {
assert (LOpts.getGCMode() != LangOptions::GCOnly);
ASTContext& Ctx = BR.getContext();
ObjCInterfaceDecl* ID = D->getClassInterface();
// Does the class contain any ivars that are pointers (or id<...>)?
// If not, skip the check entirely.
// NOTE: This is motivated by PR 2517:
// http://llvm.org/bugs/show_bug.cgi?id=2517
bool containsPointerIvar = false;
IdentifierInfo* SelII = &Ctx.Idents.get("SEL");
for (ObjCInterfaceDecl::ivar_iterator I=ID->ivar_begin(), E=ID->ivar_end();
I!=E; ++I) {
ObjCIvarDecl* ID = *I;
QualType T = ID->getType();
if ((T->isPointerType() || T->isObjCQualifiedIdType()) &&
(ID->getAttr<IBOutletAttr>() == 0 && // Skip IBOutlets.
!isSEL(T, SelII))) { // Skip SEL ivars.
containsPointerIvar = true;
break;
}
}
if (!containsPointerIvar)
return;
// Determine if the class subclasses NSObject.
IdentifierInfo* NSObjectII = &Ctx.Idents.get("NSObject");
for ( ; ID ; ID = ID->getSuperClass())
if (ID->getIdentifier() == NSObjectII)
break;
if (!ID)
return;
// Get the "dealloc" selector.
IdentifierInfo* II = &Ctx.Idents.get("dealloc");
Selector S = Ctx.Selectors.getSelector(0, &II);
ObjCMethodDecl* MD = 0;
// Scan the instance methods for "dealloc".
for (ObjCImplementationDecl::instmeth_iterator I = D->instmeth_begin(),
E = D->instmeth_end(); I!=E; ++I) {
if ((*I)->getSelector() == S) {
MD = *I;
break;
}
}
if (!MD) { // No dealloc found.
const char* name = LOpts.getGCMode() == LangOptions::NonGC
? "missing -dealloc"
: "missing -dealloc (Hybrid MM, non-GC)";
std::ostringstream os;
os << "Objective-C class '" << D->getName()
<< "' lacks a 'dealloc' instance method";
BR.EmitBasicReport(name, os.str().c_str(), D->getLocStart());
return;
}
// dealloc found. Scan for missing [super dealloc].
if (MD->getBody() && !scan_dealloc(MD->getBody(), S)) {
const char* name = LOpts.getGCMode() == LangOptions::NonGC
? "missing [super dealloc]"
: "missing [super dealloc] (Hybrid MM, non-GC)";
std::ostringstream os;
os << "The 'dealloc' instance method in Objective-C class '" << D->getName()
<< "' does not send a 'dealloc' message to its super class"
" (missing [super dealloc])";
BR.EmitBasicReport(name, os.str().c_str(), D->getLocStart());
return;
}
}
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