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// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "CheckFieldsVisitor.h"
#include <cassert>
#include "Config.h"
#include "RecordInfo.h"
#include "llvm/Support/ErrorHandling.h"
CheckFieldsVisitor::CheckFieldsVisitor(const BlinkGCPluginOptions& options)
: options_(options), current_(0), stack_allocated_host_(false) {}
CheckFieldsVisitor::Errors& CheckFieldsVisitor::invalid_fields() {
return invalid_fields_;
}
bool CheckFieldsVisitor::ContainsInvalidFields(RecordInfo* info) {
stack_allocated_host_ = info->IsStackAllocated();
managed_host_ =
stack_allocated_host_ || info->IsGCAllocated() || info->IsNewDisallowed();
for (RecordInfo::Fields::iterator it = info->GetFields().begin();
it != info->GetFields().end();
++it) {
context().clear();
current_ = &it->second;
current_->edge()->Accept(this);
}
return !invalid_fields_.empty();
}
void CheckFieldsVisitor::AtMember(Member*) {
if (managed_host_)
return;
// A member is allowed to appear in the context of a root.
for (Context::iterator it = context().begin();
it != context().end();
++it) {
if ((*it)->Kind() == Edge::kRoot)
return;
}
bool is_ptr = Parent() && (Parent()->IsRawPtr() || Parent()->IsRefPtr());
invalid_fields_.push_back(std::make_pair(
current_, is_ptr ? kPtrToMemberInUnmanaged : kMemberInUnmanaged));
}
void CheckFieldsVisitor::AtWeakMember(WeakMember*) {
AtMember(nullptr);
}
void CheckFieldsVisitor::AtIterator(Iterator* edge) {
if (!managed_host_)
return;
if (!stack_allocated_host_ && edge->on_heap())
invalid_fields_.push_back(std::make_pair(current_, kIteratorToGCManaged));
}
namespace {
CheckFieldsVisitor::Error InvalidSmartPtr(Edge* ptr, bool is_gced) {
if (ptr->IsRefPtr()) {
return is_gced ? CheckFieldsVisitor::Error::kRefPtrToGCManaged
: CheckFieldsVisitor::Error::kRefPtrToTraceable;
}
if (ptr->IsUniquePtr()) {
return is_gced ? CheckFieldsVisitor::Error::kUniquePtrToGCManaged
: CheckFieldsVisitor::Error::kUniquePtrToTraceable;
}
llvm_unreachable("Unknown smart pointer kind");
}
} // namespace
void CheckFieldsVisitor::AtValue(Value* edge) {
RecordInfo* record = edge->value();
// TODO: what should we do to check unions?
if (record->record()->isUnion()) {
return;
}
// Don't allow unmanaged classes to contain traceable part-objects.
const bool child_is_part_object = record->IsNewDisallowed() && !Parent();
if (!managed_host_ && child_is_part_object && record->RequiresTraceMethod()) {
invalid_fields_.push_back(
std::make_pair(current_, kTraceablePartObjectInUnmanaged));
return;
}
if (!stack_allocated_host_ && record->IsStackAllocated() &&
!Config::IsStackAllocatedIgnoreAnnotated(current_->field())) {
invalid_fields_.push_back(std::make_pair(current_, kPtrFromHeapToStack));
return;
}
if (!Parent() && record->IsGCDerived() && !record->IsGCMixin()) {
invalid_fields_.push_back(std::make_pair(current_, kGCDerivedPartObject));
return;
}
// Members/WeakMembers are prohibited if the host is stack allocated, but
// heap collections with Members are okay.
if (stack_allocated_host_ && Parent() &&
(Parent()->IsMember() || Parent()->IsWeakMember())) {
if (!GrandParent() ||
(!GrandParent()->IsCollection() && !GrandParent()->IsRawPtr() &&
!GrandParent()->IsRefPtr())) {
invalid_fields_.push_back(
std::make_pair(current_, kMemberInStackAllocated));
return;
}
}
// If in a stack allocated context, be fairly insistent that T in Member<T>
// is GC allocated, as stack allocated objects do not have a trace()
// that separately verifies the validity of Member<T>.
//
// Notice that an error is only reported if T's definition is in scope;
// we do not require that it must be brought into scope as that would
// prevent declarations of mutually dependent class types.
//
// (Note: Member<>'s constructor will at run-time verify that the
// pointer it wraps is indeed heap allocated.)
if (stack_allocated_host_ && Parent() &&
(Parent()->IsMember() || Parent()->IsWeakMember()) &&
edge->value()->HasDefinition() && !edge->value()->IsGCAllocated()) {
invalid_fields_.push_back(std::make_pair(current_, kMemberToGCUnmanaged));
return;
}
if (!Parent() || (!edge->value()->IsGCAllocated() &&
!edge->value()
->NeedsTracing(Edge::NeedsTracingOption::kRecursive)
.IsNeeded())) {
return;
}
// Disallow unique_ptr<T>, scoped_refptr<T>
if (Parent()->IsUniquePtr() ||
(Parent()->IsRefPtr() && (Parent()->Kind() == Edge::kStrong))) {
invalid_fields_.push_back(std::make_pair(
current_, InvalidSmartPtr(Parent(), edge->value()->IsGCAllocated())));
return;
}
if (Parent()->IsRawPtr() && !stack_allocated_host_) {
RawPtr* rawPtr = static_cast<RawPtr*>(Parent());
Error error = edge->value()->IsGCAllocated()
? (rawPtr->HasReferenceType() ? kReferencePtrToGCManaged
: kRawPtrToGCManaged)
: (rawPtr->HasReferenceType() ? kReferencePtrToTraceable
: kRawPtrToTraceable);
invalid_fields_.push_back(std::make_pair(current_, error));
}
}
void CheckFieldsVisitor::AtCollection(Collection* edge) {
if (GrandParent() &&
(GrandParent()->IsRawPtr() || GrandParent()->IsRefPtr())) {
// Don't alert on pointers to unique_ptr. Alerting on the pointed unique_ptr
// should suffice.
return;
}
if (edge->on_heap() && Parent() && Parent()->IsUniquePtr())
invalid_fields_.push_back(std::make_pair(current_, kUniquePtrToGCManaged));
}
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