From fd035e6496665b1f1197868e21cb0a4594e8db6e Mon Sep 17 00:00:00 2001
From: rdivacky <rdivacky@FreeBSD.org>
Date: Tue, 16 Feb 2010 09:31:36 +0000
Subject: Update clang to r96341.
---
lib/Checker/CheckObjCDealloc.cpp | 258 +++++++++++++++++++++++++++++++++++++++
1 file changed, 258 insertions(+)
create mode 100644 lib/Checker/CheckObjCDealloc.cpp
(limited to 'lib/Checker/CheckObjCDealloc.cpp')
diff --git a/lib/Checker/CheckObjCDealloc.cpp b/lib/Checker/CheckObjCDealloc.cpp
new file mode 100644
index 0000000..d9606f1
--- /dev/null
+++ b/lib/Checker/CheckObjCDealloc.cpp
@@ -0,0 +1,258 @@
+//==- 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/Checker/Checkers/LocalCheckers.h"
+#include "clang/Checker/BugReporter/PathDiagnostic.h"
+#include "clang/Checker/BugReporter/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,
+ Expr::NPC_ValueDependentIsNull))
+ 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,
+ Expr::NPC_ValueDependentIsNull)) {
+ // 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(const ObjCImplementationDecl* D,
+ const LangOptions& LOpts, BugReporter& BR) {
+
+ assert (LOpts.getGCMode() != LangOptions::GCOnly);
+
+ ASTContext& Ctx = BR.getContext();
+ const 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 (!T->isObjCObjectPointerType() ||
+ ID->getAttr<IBOutletAttr>()) // Skip IBOutlets.
+ continue;
+
+ containsPointerIvar = true;
+ break;
+ }
+
+ if (!containsPointerIvar)
+ return;
+
+ // Determine if the class subclasses NSObject.
+ IdentifierInfo* NSObjectII = &Ctx.Idents.get("NSObject");
+ IdentifierInfo* SenTestCaseII = &Ctx.Idents.get("SenTestCase");
+
+
+ for ( ; ID ; ID = ID->getSuperClass()) {
+ IdentifierInfo *II = ID->getIdentifier();
+
+ if (II == NSObjectII)
+ break;
+
+ // FIXME: For now, ignore classes that subclass SenTestCase, as these don't
+ // need to implement -dealloc. They implement tear down in another way,
+ // which we should try and catch later.
+ // http://llvm.org/bugs/show_bug.cgi?id=3187
+ if (II == SenTestCaseII)
+ return;
+ }
+
+ 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(), 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(), 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 (!T->isObjCObjectPointerType()) // 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(), (*I)->getLocation());
+ }
+ }
+}
+
--
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