forked from OSchip/llvm-project
246 lines
8.1 KiB
C++
246 lines
8.1 KiB
C++
//==- 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 "llvm/Support/raw_ostream.h"
|
|
|
|
using namespace clang;
|
|
|
|
static bool scan_dealloc(Stmt* S, Selector Dealloc) {
|
|
|
|
if (ObjCMessageExpr* ME = dyn_cast<ObjCMessageExpr>(S))
|
|
if (ME->getSelector() == Dealloc)
|
|
if(ME->getReceiver())
|
|
if (Expr* Receiver = ME->getReceiver()->IgnoreParenCasts())
|
|
return isa<ObjCSuperExpr>(Receiver);
|
|
|
|
// 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 scan_ivar_release(Stmt* S, ObjCIvarDecl* ID,
|
|
const ObjCPropertyDecl* PD,
|
|
Selector Release,
|
|
IdentifierInfo* SelfII,
|
|
ASTContext& Ctx) {
|
|
|
|
// [mMyIvar release]
|
|
if (ObjCMessageExpr* ME = dyn_cast<ObjCMessageExpr>(S))
|
|
if (ME->getSelector() == Release)
|
|
if(ME->getReceiver())
|
|
if (Expr* Receiver = ME->getReceiver()->IgnoreParenCasts())
|
|
if (ObjCIvarRefExpr* E = dyn_cast<ObjCIvarRefExpr>(Receiver))
|
|
if (E->getDecl() == ID)
|
|
return true;
|
|
|
|
// [self setMyIvar:nil];
|
|
if (ObjCMessageExpr* ME = dyn_cast<ObjCMessageExpr>(S))
|
|
if(ME->getReceiver())
|
|
if (Expr* Receiver = ME->getReceiver()->IgnoreParenCasts())
|
|
if (DeclRefExpr* E = dyn_cast<DeclRefExpr>(Receiver))
|
|
if (E->getDecl()->getIdentifier() == SelfII)
|
|
if (ME->getMethodDecl() == PD->getSetterMethodDecl() &&
|
|
ME->getNumArgs() == 1 &&
|
|
ME->getArg(0)->isNullPointerConstant(Ctx))
|
|
return true;
|
|
|
|
// self.myIvar = nil;
|
|
if (BinaryOperator* BO = dyn_cast<BinaryOperator>(S))
|
|
if (BO->isAssignmentOp())
|
|
if(ObjCPropertyRefExpr* PRE =
|
|
dyn_cast<ObjCPropertyRefExpr>(BO->getLHS()->IgnoreParenCasts()))
|
|
if(PRE->getProperty() == PD)
|
|
if(BO->getRHS()->isNullPointerConstant(Ctx)) {
|
|
// This is only a 'release' if the property kind is not
|
|
// 'assign'.
|
|
return PD->getSetterKind() != ObjCPropertyDecl::Assign;;
|
|
}
|
|
|
|
// Recurse to children.
|
|
for (Stmt::child_iterator I = S->child_begin(), E= S->child_end(); I!=E; ++I)
|
|
if (*I && scan_ivar_release(*I, ID, PD, Release, SelfII, Ctx))
|
|
return true;
|
|
|
|
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;
|
|
|
|
for (ObjCInterfaceDecl::ivar_iterator I=ID->ivar_begin(), E=ID->ivar_end();
|
|
I!=E; ++I) {
|
|
|
|
ObjCIvarDecl* ID = *I;
|
|
QualType T = ID->getType();
|
|
|
|
if (!Ctx.isObjCObjectPointerType(T) ||
|
|
ID->getAttr<IBOutletAttr>()) // Skip IBOutlets.
|
|
continue;
|
|
|
|
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::string buf;
|
|
llvm::raw_string_ostream os(buf);
|
|
os << "Objective-C class '" << D->getNameAsString()
|
|
<< "' 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::string buf;
|
|
llvm::raw_string_ostream os(buf);
|
|
os << "The 'dealloc' instance method in Objective-C class '"
|
|
<< D->getNameAsString()
|
|
<< "' does not send a 'dealloc' message to its super class"
|
|
" (missing [super dealloc])";
|
|
|
|
BR.EmitBasicReport(name, os.str().c_str(), D->getLocStart());
|
|
return;
|
|
}
|
|
|
|
// Get the "release" selector.
|
|
IdentifierInfo* RII = &Ctx.Idents.get("release");
|
|
Selector RS = Ctx.Selectors.getSelector(0, &RII);
|
|
|
|
// Get the "self" identifier
|
|
IdentifierInfo* SelfII = &Ctx.Idents.get("self");
|
|
|
|
// Scan for missing and extra releases of ivars used by implementations
|
|
// of synthesized properties
|
|
for (ObjCImplementationDecl::propimpl_iterator I = D->propimpl_begin(),
|
|
E = D->propimpl_end(); I!=E; ++I) {
|
|
|
|
// We can only check the synthesized properties
|
|
if((*I)->getPropertyImplementation() != ObjCPropertyImplDecl::Synthesize)
|
|
continue;
|
|
|
|
ObjCIvarDecl* ID = (*I)->getPropertyIvarDecl();
|
|
if (!ID)
|
|
continue;
|
|
|
|
QualType T = ID->getType();
|
|
if (!Ctx.isObjCObjectPointerType(T)) // Skip non-pointer ivars
|
|
continue;
|
|
|
|
const ObjCPropertyDecl* PD = (*I)->getPropertyDecl();
|
|
if(!PD)
|
|
continue;
|
|
|
|
// ivars cannot be set via read-only properties, so we'll skip them
|
|
if(PD->isReadOnly())
|
|
continue;
|
|
|
|
// ivar must be released if and only if the kind of setter was not 'assign'
|
|
bool requiresRelease = PD->getSetterKind() != ObjCPropertyDecl::Assign;
|
|
if(scan_ivar_release(MD->getBody(), ID, PD, RS, SelfII, Ctx)
|
|
!= requiresRelease) {
|
|
const char *name;
|
|
const char* category = "Memory (Core Foundation/Objective-C)";
|
|
|
|
std::string buf;
|
|
llvm::raw_string_ostream os(buf);
|
|
|
|
if(requiresRelease) {
|
|
name = LOpts.getGCMode() == LangOptions::NonGC
|
|
? "missing ivar release (leak)"
|
|
: "missing ivar release (Hybrid MM, non-GC)";
|
|
|
|
os << "The '" << ID->getNameAsString()
|
|
<< "' instance variable was retained by a synthesized property but "
|
|
"wasn't released in 'dealloc'";
|
|
} else {
|
|
name = LOpts.getGCMode() == LangOptions::NonGC
|
|
? "extra ivar release (use-after-release)"
|
|
: "extra ivar release (Hybrid MM, non-GC)";
|
|
|
|
os << "The '" << ID->getNameAsString()
|
|
<< "' instance variable was not retained by a synthesized property "
|
|
"but was released in 'dealloc'";
|
|
}
|
|
|
|
BR.EmitBasicReport(name, category,
|
|
os.str().c_str(), (*I)->getLocation());
|
|
}
|
|
}
|
|
}
|
|
|