llvm-project/clang/lib/ARCMigrate/TransGCAttrs.cpp
Puyan Lotfi 9721fbf85b [NFC] Refactoring PropertyAttributeKind for ObjCPropertyDecl and ObjCDeclSpec.
This is a code clean up of the PropertyAttributeKind and
ObjCPropertyAttributeKind enums in ObjCPropertyDecl and ObjCDeclSpec that are
exactly identical. This non-functional change consolidates these enums
into one. The changes are to many files across clang (and comments in LLVM) so
that everything refers to the new consolidated enum in DeclObjCCommon.h.

2nd Landing Attempt...

Differential Revision: https://reviews.llvm.org/D77233
2020-04-23 17:21:25 -04:00

353 lines
11 KiB
C++

//===--- TransGCAttrs.cpp - Transformations to ARC mode --------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "Transforms.h"
#include "Internals.h"
#include "clang/AST/ASTContext.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/Lexer.h"
#include "clang/Sema/SemaDiagnostic.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/Support/SaveAndRestore.h"
using namespace clang;
using namespace arcmt;
using namespace trans;
namespace {
/// Collects all the places where GC attributes __strong/__weak occur.
class GCAttrsCollector : public RecursiveASTVisitor<GCAttrsCollector> {
MigrationContext &MigrateCtx;
bool FullyMigratable;
std::vector<ObjCPropertyDecl *> &AllProps;
typedef RecursiveASTVisitor<GCAttrsCollector> base;
public:
GCAttrsCollector(MigrationContext &ctx,
std::vector<ObjCPropertyDecl *> &AllProps)
: MigrateCtx(ctx), FullyMigratable(false),
AllProps(AllProps) { }
bool shouldWalkTypesOfTypeLocs() const { return false; }
bool VisitAttributedTypeLoc(AttributedTypeLoc TL) {
handleAttr(TL);
return true;
}
bool TraverseDecl(Decl *D) {
if (!D || D->isImplicit())
return true;
SaveAndRestore<bool> Save(FullyMigratable, isMigratable(D));
if (ObjCPropertyDecl *PropD = dyn_cast<ObjCPropertyDecl>(D)) {
lookForAttribute(PropD, PropD->getTypeSourceInfo());
AllProps.push_back(PropD);
} else if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
lookForAttribute(DD, DD->getTypeSourceInfo());
}
return base::TraverseDecl(D);
}
void lookForAttribute(Decl *D, TypeSourceInfo *TInfo) {
if (!TInfo)
return;
TypeLoc TL = TInfo->getTypeLoc();
while (TL) {
if (QualifiedTypeLoc QL = TL.getAs<QualifiedTypeLoc>()) {
TL = QL.getUnqualifiedLoc();
} else if (AttributedTypeLoc Attr = TL.getAs<AttributedTypeLoc>()) {
if (handleAttr(Attr, D))
break;
TL = Attr.getModifiedLoc();
} else if (MacroQualifiedTypeLoc MDTL =
TL.getAs<MacroQualifiedTypeLoc>()) {
TL = MDTL.getInnerLoc();
} else if (ArrayTypeLoc Arr = TL.getAs<ArrayTypeLoc>()) {
TL = Arr.getElementLoc();
} else if (PointerTypeLoc PT = TL.getAs<PointerTypeLoc>()) {
TL = PT.getPointeeLoc();
} else if (ReferenceTypeLoc RT = TL.getAs<ReferenceTypeLoc>())
TL = RT.getPointeeLoc();
else
break;
}
}
bool handleAttr(AttributedTypeLoc TL, Decl *D = nullptr) {
auto *OwnershipAttr = TL.getAttrAs<ObjCOwnershipAttr>();
if (!OwnershipAttr)
return false;
SourceLocation Loc = OwnershipAttr->getLocation();
unsigned RawLoc = Loc.getRawEncoding();
if (MigrateCtx.AttrSet.count(RawLoc))
return true;
ASTContext &Ctx = MigrateCtx.Pass.Ctx;
SourceManager &SM = Ctx.getSourceManager();
if (Loc.isMacroID())
Loc = SM.getImmediateExpansionRange(Loc).getBegin();
StringRef Spell = OwnershipAttr->getKind()->getName();
MigrationContext::GCAttrOccurrence::AttrKind Kind;
if (Spell == "strong")
Kind = MigrationContext::GCAttrOccurrence::Strong;
else if (Spell == "weak")
Kind = MigrationContext::GCAttrOccurrence::Weak;
else
return false;
MigrateCtx.AttrSet.insert(RawLoc);
MigrateCtx.GCAttrs.push_back(MigrationContext::GCAttrOccurrence());
MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs.back();
Attr.Kind = Kind;
Attr.Loc = Loc;
Attr.ModifiedType = TL.getModifiedLoc().getType();
Attr.Dcl = D;
Attr.FullyMigratable = FullyMigratable;
return true;
}
bool isMigratable(Decl *D) {
if (isa<TranslationUnitDecl>(D))
return false;
if (isInMainFile(D))
return true;
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
return FD->hasBody();
if (ObjCContainerDecl *ContD = dyn_cast<ObjCContainerDecl>(D))
return hasObjCImpl(ContD);
if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
for (const auto *MI : RD->methods()) {
if (MI->isOutOfLine())
return true;
}
return false;
}
return isMigratable(cast<Decl>(D->getDeclContext()));
}
static bool hasObjCImpl(Decl *D) {
if (!D)
return false;
if (ObjCContainerDecl *ContD = dyn_cast<ObjCContainerDecl>(D)) {
if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(ContD))
return ID->getImplementation() != nullptr;
if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(ContD))
return CD->getImplementation() != nullptr;
return isa<ObjCImplDecl>(ContD);
}
return false;
}
bool isInMainFile(Decl *D) {
if (!D)
return false;
for (auto I : D->redecls())
if (!isInMainFile(I->getLocation()))
return false;
return true;
}
bool isInMainFile(SourceLocation Loc) {
if (Loc.isInvalid())
return false;
SourceManager &SM = MigrateCtx.Pass.Ctx.getSourceManager();
return SM.isInFileID(SM.getExpansionLoc(Loc), SM.getMainFileID());
}
};
} // anonymous namespace
static void errorForGCAttrsOnNonObjC(MigrationContext &MigrateCtx) {
TransformActions &TA = MigrateCtx.Pass.TA;
for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs[i];
if (Attr.FullyMigratable && Attr.Dcl) {
if (Attr.ModifiedType.isNull())
continue;
if (!Attr.ModifiedType->isObjCRetainableType()) {
TA.reportError("GC managed memory will become unmanaged in ARC",
Attr.Loc);
}
}
}
}
static void checkWeakGCAttrs(MigrationContext &MigrateCtx) {
TransformActions &TA = MigrateCtx.Pass.TA;
for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs[i];
if (Attr.Kind == MigrationContext::GCAttrOccurrence::Weak) {
if (Attr.ModifiedType.isNull() ||
!Attr.ModifiedType->isObjCRetainableType())
continue;
if (!canApplyWeak(MigrateCtx.Pass.Ctx, Attr.ModifiedType,
/*AllowOnUnknownClass=*/true)) {
Transaction Trans(TA);
if (!MigrateCtx.RemovedAttrSet.count(Attr.Loc.getRawEncoding()))
TA.replaceText(Attr.Loc, "__weak", "__unsafe_unretained");
TA.clearDiagnostic(diag::err_arc_weak_no_runtime,
diag::err_arc_unsupported_weak_class,
Attr.Loc);
}
}
}
}
typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
static void checkAllAtProps(MigrationContext &MigrateCtx,
SourceLocation AtLoc,
IndivPropsTy &IndProps) {
if (IndProps.empty())
return;
for (IndivPropsTy::iterator
PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
QualType T = (*PI)->getType();
if (T.isNull() || !T->isObjCRetainableType())
return;
}
SmallVector<std::pair<AttributedTypeLoc, ObjCPropertyDecl *>, 4> ATLs;
bool hasWeak = false, hasStrong = false;
ObjCPropertyAttribute::Kind Attrs = ObjCPropertyAttribute::kind_noattr;
for (IndivPropsTy::iterator
PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
ObjCPropertyDecl *PD = *PI;
Attrs = PD->getPropertyAttributesAsWritten();
TypeSourceInfo *TInfo = PD->getTypeSourceInfo();
if (!TInfo)
return;
TypeLoc TL = TInfo->getTypeLoc();
if (AttributedTypeLoc ATL =
TL.getAs<AttributedTypeLoc>()) {
ATLs.push_back(std::make_pair(ATL, PD));
if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
hasWeak = true;
} else if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Strong)
hasStrong = true;
else
return;
}
}
if (ATLs.empty())
return;
if (hasWeak && hasStrong)
return;
TransformActions &TA = MigrateCtx.Pass.TA;
Transaction Trans(TA);
if (GCAttrsCollector::hasObjCImpl(
cast<Decl>(IndProps.front()->getDeclContext()))) {
if (hasWeak)
MigrateCtx.AtPropsWeak.insert(AtLoc.getRawEncoding());
} else {
StringRef toAttr = "strong";
if (hasWeak) {
if (canApplyWeak(MigrateCtx.Pass.Ctx, IndProps.front()->getType(),
/*AllowOnUnknownClass=*/true))
toAttr = "weak";
else
toAttr = "unsafe_unretained";
}
if (Attrs & ObjCPropertyAttribute::kind_assign)
MigrateCtx.rewritePropertyAttribute("assign", toAttr, AtLoc);
else
MigrateCtx.addPropertyAttribute(toAttr, AtLoc);
}
for (unsigned i = 0, e = ATLs.size(); i != e; ++i) {
SourceLocation Loc = ATLs[i].first.getAttr()->getLocation();
if (Loc.isMacroID())
Loc = MigrateCtx.Pass.Ctx.getSourceManager()
.getImmediateExpansionRange(Loc)
.getBegin();
TA.remove(Loc);
TA.clearDiagnostic(diag::err_objc_property_attr_mutually_exclusive, AtLoc);
TA.clearDiagnostic(diag::err_arc_inconsistent_property_ownership,
ATLs[i].second->getLocation());
MigrateCtx.RemovedAttrSet.insert(Loc.getRawEncoding());
}
}
static void checkAllProps(MigrationContext &MigrateCtx,
std::vector<ObjCPropertyDecl *> &AllProps) {
typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
llvm::DenseMap<unsigned, IndivPropsTy> AtProps;
for (unsigned i = 0, e = AllProps.size(); i != e; ++i) {
ObjCPropertyDecl *PD = AllProps[i];
if (PD->getPropertyAttributesAsWritten() &
(ObjCPropertyAttribute::kind_assign |
ObjCPropertyAttribute::kind_readonly)) {
SourceLocation AtLoc = PD->getAtLoc();
if (AtLoc.isInvalid())
continue;
unsigned RawAt = AtLoc.getRawEncoding();
AtProps[RawAt].push_back(PD);
}
}
for (llvm::DenseMap<unsigned, IndivPropsTy>::iterator
I = AtProps.begin(), E = AtProps.end(); I != E; ++I) {
SourceLocation AtLoc = SourceLocation::getFromRawEncoding(I->first);
IndivPropsTy &IndProps = I->second;
checkAllAtProps(MigrateCtx, AtLoc, IndProps);
}
}
void GCAttrsTraverser::traverseTU(MigrationContext &MigrateCtx) {
std::vector<ObjCPropertyDecl *> AllProps;
GCAttrsCollector(MigrateCtx, AllProps).TraverseDecl(
MigrateCtx.Pass.Ctx.getTranslationUnitDecl());
errorForGCAttrsOnNonObjC(MigrateCtx);
checkAllProps(MigrateCtx, AllProps);
checkWeakGCAttrs(MigrateCtx);
}
void MigrationContext::dumpGCAttrs() {
llvm::errs() << "\n################\n";
for (unsigned i = 0, e = GCAttrs.size(); i != e; ++i) {
GCAttrOccurrence &Attr = GCAttrs[i];
llvm::errs() << "KIND: "
<< (Attr.Kind == GCAttrOccurrence::Strong ? "strong" : "weak");
llvm::errs() << "\nLOC: ";
Attr.Loc.print(llvm::errs(), Pass.Ctx.getSourceManager());
llvm::errs() << "\nTYPE: ";
Attr.ModifiedType.dump();
if (Attr.Dcl) {
llvm::errs() << "DECL:\n";
Attr.Dcl->dump();
} else {
llvm::errs() << "DECL: NONE";
}
llvm::errs() << "\nMIGRATABLE: " << Attr.FullyMigratable;
llvm::errs() << "\n----------------\n";
}
llvm::errs() << "\n################\n";
}