llvm-capstone/clang/lib/ARCMigrate/TransGCAttrs.cpp
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

351 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 (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;
ObjCPropertyDecl::PropertyAttributeKind
Attrs = ObjCPropertyDecl::OBJC_PR_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(),
/*AllowOnUnkwownClass=*/true))
toAttr = "weak";
else
toAttr = "unsafe_unretained";
}
if (Attrs & ObjCPropertyDecl::OBJC_PR_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() &
(ObjCPropertyDecl::OBJC_PR_assign |
ObjCPropertyDecl::OBJC_PR_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";
}