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// Copyright (c) 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "source/fuzz/transformation_store.h"
#include "source/fuzz/fuzzer_util.h"
#include "source/fuzz/instruction_descriptor.h"
namespace spvtools {
namespace fuzz {
TransformationStore::TransformationStore(
const spvtools::fuzz::protobufs::TransformationStore& message)
: message_(message) {}
TransformationStore::TransformationStore(
uint32_t pointer_id, uint32_t value_id,
const protobufs::InstructionDescriptor& instruction_to_insert_before) {
message_.set_pointer_id(pointer_id);
message_.set_value_id(value_id);
*message_.mutable_instruction_to_insert_before() =
instruction_to_insert_before;
}
bool TransformationStore::IsApplicable(
opt::IRContext* ir_context,
const TransformationContext& transformation_context) const {
// The pointer must exist and have a type.
auto pointer = ir_context->get_def_use_mgr()->GetDef(message_.pointer_id());
if (!pointer || !pointer->type_id()) {
return false;
}
// The pointer type must indeed be a pointer.
auto pointer_type = ir_context->get_def_use_mgr()->GetDef(pointer->type_id());
assert(pointer_type && "Type id must be defined.");
if (pointer_type->opcode() != SpvOpTypePointer) {
return false;
}
// The pointer must not be read only.
if (pointer->IsReadOnlyPointer()) {
return false;
}
// We do not want to allow storing to null or undefined pointers.
switch (pointer->opcode()) {
case SpvOpConstantNull:
case SpvOpUndef:
return false;
default:
break;
}
// Determine which instruction we should be inserting before.
auto insert_before =
FindInstruction(message_.instruction_to_insert_before(), ir_context);
// It must exist, ...
if (!insert_before) {
return false;
}
// ... and it must be legitimate to insert a store before it.
if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(SpvOpStore,
insert_before)) {
return false;
}
// The block we are inserting into needs to be dead, or else the pointee type
// of the pointer we are storing to needs to be irrelevant (otherwise the
// store could impact on the observable behaviour of the module).
if (!transformation_context.GetFactManager()->BlockIsDead(
ir_context->get_instr_block(insert_before)->id()) &&
!transformation_context.GetFactManager()->PointeeValueIsIrrelevant(
message_.pointer_id())) {
return false;
}
// The value being stored needs to exist and have a type.
auto value = ir_context->get_def_use_mgr()->GetDef(message_.value_id());
if (!value || !value->type_id()) {
return false;
}
// The type of the value must match the pointee type.
if (pointer_type->GetSingleWordInOperand(1) != value->type_id()) {
return false;
}
// The pointer needs to be available at the insertion point.
if (!fuzzerutil::IdIsAvailableBeforeInstruction(ir_context, insert_before,
message_.pointer_id())) {
return false;
}
// The value needs to be available at the insertion point.
return fuzzerutil::IdIsAvailableBeforeInstruction(ir_context, insert_before,
message_.value_id());
}
void TransformationStore::Apply(opt::IRContext* ir_context,
TransformationContext* /*unused*/) const {
FindInstruction(message_.instruction_to_insert_before(), ir_context)
->InsertBefore(MakeUnique<opt::Instruction>(
ir_context, SpvOpStore, 0, 0,
opt::Instruction::OperandList(
{{SPV_OPERAND_TYPE_ID, {message_.pointer_id()}},
{SPV_OPERAND_TYPE_ID, {message_.value_id()}}})));
ir_context->InvalidateAnalysesExceptFor(opt::IRContext::kAnalysisNone);
}
protobufs::Transformation TransformationStore::ToMessage() const {
protobufs::Transformation result;
*result.mutable_store() = message_;
return result;
}
std::unordered_set<uint32_t> TransformationStore::GetFreshIds() const {
return std::unordered_set<uint32_t>();
}
} // namespace fuzz
} // namespace spvtools
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