Andrea Falcone | 1c4977f | 2020-07-23 10:58:25 -0400 | [diff] [blame^] | 1 | // Copyright (c) 2019 Google LLC |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | #include "source/fuzz/transformation_copy_object.h" |
| 16 | |
| 17 | #include "source/fuzz/fuzzer_util.h" |
| 18 | #include "source/fuzz/instruction_descriptor.h" |
| 19 | #include "source/opt/instruction.h" |
| 20 | #include "source/util/make_unique.h" |
| 21 | |
| 22 | namespace spvtools { |
| 23 | namespace fuzz { |
| 24 | |
| 25 | TransformationCopyObject::TransformationCopyObject( |
| 26 | const protobufs::TransformationCopyObject& message) |
| 27 | : message_(message) {} |
| 28 | |
| 29 | TransformationCopyObject::TransformationCopyObject( |
| 30 | uint32_t object, |
| 31 | const protobufs::InstructionDescriptor& instruction_to_insert_before, |
| 32 | uint32_t fresh_id) { |
| 33 | message_.set_object(object); |
| 34 | *message_.mutable_instruction_to_insert_before() = |
| 35 | instruction_to_insert_before; |
| 36 | message_.set_fresh_id(fresh_id); |
| 37 | } |
| 38 | |
| 39 | bool TransformationCopyObject::IsApplicable( |
| 40 | opt::IRContext* context, const FactManager& /*fact_manager*/) const { |
| 41 | if (!fuzzerutil::IsFreshId(context, message_.fresh_id())) { |
| 42 | // We require the id for the object copy to be unused. |
| 43 | return false; |
| 44 | } |
| 45 | // The id of the object to be copied must exist |
| 46 | auto object_inst = context->get_def_use_mgr()->GetDef(message_.object()); |
| 47 | if (!object_inst) { |
| 48 | return false; |
| 49 | } |
| 50 | if (!fuzzerutil::CanMakeSynonymOf(context, object_inst)) { |
| 51 | return false; |
| 52 | } |
| 53 | |
| 54 | auto insert_before = |
| 55 | FindInstruction(message_.instruction_to_insert_before(), context); |
| 56 | if (!insert_before) { |
| 57 | // The instruction before which the copy should be inserted was not found. |
| 58 | return false; |
| 59 | } |
| 60 | |
| 61 | if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(SpvOpCopyObject, |
| 62 | insert_before)) { |
| 63 | return false; |
| 64 | } |
| 65 | |
| 66 | // |message_object| must be available at the point where we want to add the |
| 67 | // copy. It is available if it is at global scope (in which case it has no |
| 68 | // block), or if it dominates the point of insertion but is different from the |
| 69 | // point of insertion. |
| 70 | // |
| 71 | // The reason why the object needs to be different from the insertion point is |
| 72 | // that the copy will be added *before* this point, and we do not want to |
| 73 | // insert it before the object's defining instruction. |
| 74 | return !context->get_instr_block(object_inst) || |
| 75 | (object_inst != &*insert_before && |
| 76 | context |
| 77 | ->GetDominatorAnalysis( |
| 78 | context->get_instr_block(insert_before)->GetParent()) |
| 79 | ->Dominates(object_inst, &*insert_before)); |
| 80 | } |
| 81 | |
| 82 | void TransformationCopyObject::Apply(opt::IRContext* context, |
| 83 | FactManager* fact_manager) const { |
| 84 | auto object_inst = context->get_def_use_mgr()->GetDef(message_.object()); |
| 85 | assert(object_inst && "The object to be copied must exist."); |
| 86 | auto insert_before_inst = |
| 87 | FindInstruction(message_.instruction_to_insert_before(), context); |
| 88 | auto destination_block = context->get_instr_block(insert_before_inst); |
| 89 | assert(destination_block && "The base instruction must be in a block."); |
| 90 | auto insert_before = fuzzerutil::GetIteratorForInstruction( |
| 91 | destination_block, insert_before_inst); |
| 92 | assert(insert_before != destination_block->end() && |
| 93 | "There must be an instruction before which the copy can be inserted."); |
| 94 | |
| 95 | opt::Instruction::OperandList operands = { |
| 96 | {SPV_OPERAND_TYPE_ID, {message_.object()}}}; |
| 97 | insert_before->InsertBefore(MakeUnique<opt::Instruction>( |
| 98 | context, SpvOp::SpvOpCopyObject, object_inst->type_id(), |
| 99 | message_.fresh_id(), operands)); |
| 100 | |
| 101 | fuzzerutil::UpdateModuleIdBound(context, message_.fresh_id()); |
| 102 | context->InvalidateAnalysesExceptFor(opt::IRContext::Analysis::kAnalysisNone); |
| 103 | |
| 104 | protobufs::Fact fact; |
| 105 | fact.mutable_id_synonym_fact()->set_id(message_.object()); |
| 106 | fact.mutable_id_synonym_fact()->mutable_data_descriptor()->set_object( |
| 107 | message_.fresh_id()); |
| 108 | fact_manager->AddFact(fact, context); |
| 109 | } |
| 110 | |
| 111 | protobufs::Transformation TransformationCopyObject::ToMessage() const { |
| 112 | protobufs::Transformation result; |
| 113 | *result.mutable_copy_object() = message_; |
| 114 | return result; |
| 115 | } |
| 116 | |
| 117 | } // namespace fuzz |
| 118 | } // namespace spvtools |