| // Copyright (c) 2019 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/fuzzer_pass.h" |
| |
| #include <set> |
| |
| #include "source/fuzz/fuzzer_util.h" |
| #include "source/fuzz/id_use_descriptor.h" |
| #include "source/fuzz/instruction_descriptor.h" |
| #include "source/fuzz/transformation_add_constant_boolean.h" |
| #include "source/fuzz/transformation_add_constant_composite.h" |
| #include "source/fuzz/transformation_add_constant_null.h" |
| #include "source/fuzz/transformation_add_constant_scalar.h" |
| #include "source/fuzz/transformation_add_global_undef.h" |
| #include "source/fuzz/transformation_add_global_variable.h" |
| #include "source/fuzz/transformation_add_local_variable.h" |
| #include "source/fuzz/transformation_add_loop_preheader.h" |
| #include "source/fuzz/transformation_add_type_boolean.h" |
| #include "source/fuzz/transformation_add_type_float.h" |
| #include "source/fuzz/transformation_add_type_function.h" |
| #include "source/fuzz/transformation_add_type_int.h" |
| #include "source/fuzz/transformation_add_type_matrix.h" |
| #include "source/fuzz/transformation_add_type_pointer.h" |
| #include "source/fuzz/transformation_add_type_struct.h" |
| #include "source/fuzz/transformation_add_type_vector.h" |
| #include "source/fuzz/transformation_split_block.h" |
| |
| namespace spvtools { |
| namespace fuzz { |
| |
| FuzzerPass::FuzzerPass(opt::IRContext* ir_context, |
| TransformationContext* transformation_context, |
| FuzzerContext* fuzzer_context, |
| protobufs::TransformationSequence* transformations) |
| : ir_context_(ir_context), |
| transformation_context_(transformation_context), |
| fuzzer_context_(fuzzer_context), |
| transformations_(transformations) {} |
| |
| FuzzerPass::~FuzzerPass() = default; |
| |
| std::vector<opt::Instruction*> FuzzerPass::FindAvailableInstructions( |
| opt::Function* function, opt::BasicBlock* block, |
| const opt::BasicBlock::iterator& inst_it, |
| std::function<bool(opt::IRContext*, opt::Instruction*)> |
| instruction_is_relevant) const { |
| // TODO(afd) The following is (relatively) simple, but may end up being |
| // prohibitively inefficient, as it walks the whole dominator tree for |
| // every instruction that is considered. |
| |
| std::vector<opt::Instruction*> result; |
| // Consider all global declarations |
| for (auto& global : GetIRContext()->module()->types_values()) { |
| if (instruction_is_relevant(GetIRContext(), &global)) { |
| result.push_back(&global); |
| } |
| } |
| |
| // Consider all function parameters |
| function->ForEachParam( |
| [this, &instruction_is_relevant, &result](opt::Instruction* param) { |
| if (instruction_is_relevant(GetIRContext(), param)) { |
| result.push_back(param); |
| } |
| }); |
| |
| // Consider all previous instructions in this block |
| for (auto prev_inst_it = block->begin(); prev_inst_it != inst_it; |
| ++prev_inst_it) { |
| if (instruction_is_relevant(GetIRContext(), &*prev_inst_it)) { |
| result.push_back(&*prev_inst_it); |
| } |
| } |
| |
| // Walk the dominator tree to consider all instructions from dominating |
| // blocks |
| auto dominator_analysis = GetIRContext()->GetDominatorAnalysis(function); |
| for (auto next_dominator = dominator_analysis->ImmediateDominator(block); |
| next_dominator != nullptr; |
| next_dominator = |
| dominator_analysis->ImmediateDominator(next_dominator)) { |
| for (auto& dominating_inst : *next_dominator) { |
| if (instruction_is_relevant(GetIRContext(), &dominating_inst)) { |
| result.push_back(&dominating_inst); |
| } |
| } |
| } |
| return result; |
| } |
| |
| void FuzzerPass::ForEachInstructionWithInstructionDescriptor( |
| std::function< |
| void(opt::Function* function, opt::BasicBlock* block, |
| opt::BasicBlock::iterator inst_it, |
| const protobufs::InstructionDescriptor& instruction_descriptor)> |
| action) { |
| // Consider every block in every function. |
| for (auto& function : *GetIRContext()->module()) { |
| // Consider only reachable blocks. We do this in a separate loop to avoid |
| // recomputing the dominator analysis every time |action| changes the |
| // module. |
| std::vector<opt::BasicBlock*> reachable_blocks; |
| |
| const auto* dominator_analysis = |
| GetIRContext()->GetDominatorAnalysis(&function); |
| for (auto& block : function) { |
| if (dominator_analysis->IsReachable(&block)) { |
| reachable_blocks.push_back(&block); |
| } |
| } |
| |
| for (auto* block : reachable_blocks) { |
| // We now consider every instruction in the block, randomly deciding |
| // whether to apply a transformation before it. |
| |
| // In order for transformations to insert new instructions, they need to |
| // be able to identify the instruction to insert before. We describe an |
| // instruction via its opcode, 'opc', a base instruction 'base' that has a |
| // result id, and the number of instructions with opcode 'opc' that we |
| // should skip when searching from 'base' for the desired instruction. |
| // (An instruction that has a result id is represented by its own opcode, |
| // itself as 'base', and a skip-count of 0.) |
| std::vector<std::tuple<uint32_t, SpvOp, uint32_t>> |
| base_opcode_skip_triples; |
| |
| // The initial base instruction is the block label. |
| uint32_t base = block->id(); |
| |
| // Counts the number of times we have seen each opcode since we reset the |
| // base instruction. |
| std::map<SpvOp, uint32_t> skip_count; |
| |
| // Consider every instruction in the block. The label is excluded: it is |
| // only necessary to consider it as a base in case the first instruction |
| // in the block does not have a result id. |
| for (auto inst_it = block->begin(); inst_it != block->end(); ++inst_it) { |
| if (inst_it->HasResultId()) { |
| // In the case that the instruction has a result id, we use the |
| // instruction as its own base, and clear the skip counts we have |
| // collected. |
| base = inst_it->result_id(); |
| skip_count.clear(); |
| } |
| const SpvOp opcode = inst_it->opcode(); |
| |
| // Invoke the provided function, which might apply a transformation. |
| action(&function, block, inst_it, |
| MakeInstructionDescriptor( |
| base, opcode, |
| skip_count.count(opcode) ? skip_count.at(opcode) : 0)); |
| |
| if (!inst_it->HasResultId()) { |
| skip_count[opcode] = |
| skip_count.count(opcode) ? skip_count.at(opcode) + 1 : 1; |
| } |
| } |
| } |
| } |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateBoolType() { |
| if (auto existing_id = fuzzerutil::MaybeGetBoolType(GetIRContext())) { |
| return existing_id; |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddTypeBoolean(result)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateIntegerType(uint32_t width, bool is_signed) { |
| opt::analysis::Integer int_type(width, is_signed); |
| auto existing_id = GetIRContext()->get_type_mgr()->GetId(&int_type); |
| if (existing_id) { |
| return existing_id; |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddTypeInt(result, width, is_signed)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateFloatType(uint32_t width) { |
| opt::analysis::Float float_type(width); |
| auto existing_id = GetIRContext()->get_type_mgr()->GetId(&float_type); |
| if (existing_id) { |
| return existing_id; |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddTypeFloat(result, width)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateFunctionType( |
| uint32_t return_type_id, const std::vector<uint32_t>& argument_id) { |
| // FindFunctionType has a sigle argument for OpTypeFunction operands |
| // so we will have to copy them all in this vector |
| std::vector<uint32_t> type_ids(argument_id.size() + 1); |
| type_ids[0] = return_type_id; |
| std::copy(argument_id.begin(), argument_id.end(), type_ids.begin() + 1); |
| |
| // Check if type exists |
| auto existing_id = fuzzerutil::FindFunctionType(GetIRContext(), type_ids); |
| if (existing_id) { |
| return existing_id; |
| } |
| |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation( |
| TransformationAddTypeFunction(result, return_type_id, argument_id)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateVectorType(uint32_t component_type_id, |
| uint32_t component_count) { |
| assert(component_count >= 2 && component_count <= 4 && |
| "Precondition: component count must be in range [2, 4]."); |
| opt::analysis::Type* component_type = |
| GetIRContext()->get_type_mgr()->GetType(component_type_id); |
| assert(component_type && "Precondition: the component type must exist."); |
| opt::analysis::Vector vector_type(component_type, component_count); |
| auto existing_id = GetIRContext()->get_type_mgr()->GetId(&vector_type); |
| if (existing_id) { |
| return existing_id; |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation( |
| TransformationAddTypeVector(result, component_type_id, component_count)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateMatrixType(uint32_t column_count, |
| uint32_t row_count) { |
| assert(column_count >= 2 && column_count <= 4 && |
| "Precondition: column count must be in range [2, 4]."); |
| assert(row_count >= 2 && row_count <= 4 && |
| "Precondition: row count must be in range [2, 4]."); |
| uint32_t column_type_id = |
| FindOrCreateVectorType(FindOrCreateFloatType(32), row_count); |
| opt::analysis::Type* column_type = |
| GetIRContext()->get_type_mgr()->GetType(column_type_id); |
| opt::analysis::Matrix matrix_type(column_type, column_count); |
| auto existing_id = GetIRContext()->get_type_mgr()->GetId(&matrix_type); |
| if (existing_id) { |
| return existing_id; |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation( |
| TransformationAddTypeMatrix(result, column_type_id, column_count)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateStructType( |
| const std::vector<uint32_t>& component_type_ids) { |
| if (auto existing_id = |
| fuzzerutil::MaybeGetStructType(GetIRContext(), component_type_ids)) { |
| return existing_id; |
| } |
| auto new_id = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddTypeStruct(new_id, component_type_ids)); |
| return new_id; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreatePointerType(uint32_t base_type_id, |
| SpvStorageClass storage_class) { |
| // We do not use the type manager here, due to problems related to isomorphic |
| // but distinct structs not being regarded as different. |
| auto existing_id = fuzzerutil::MaybeGetPointerType( |
| GetIRContext(), base_type_id, storage_class); |
| if (existing_id) { |
| return existing_id; |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation( |
| TransformationAddTypePointer(result, storage_class, base_type_id)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreatePointerToIntegerType( |
| uint32_t width, bool is_signed, SpvStorageClass storage_class) { |
| return FindOrCreatePointerType(FindOrCreateIntegerType(width, is_signed), |
| storage_class); |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateIntegerConstant( |
| const std::vector<uint32_t>& words, uint32_t width, bool is_signed, |
| bool is_irrelevant) { |
| auto int_type_id = FindOrCreateIntegerType(width, is_signed); |
| if (auto constant_id = fuzzerutil::MaybeGetScalarConstant( |
| GetIRContext(), *GetTransformationContext(), words, int_type_id, |
| is_irrelevant)) { |
| return constant_id; |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddConstantScalar(result, int_type_id, |
| words, is_irrelevant)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateFloatConstant( |
| const std::vector<uint32_t>& words, uint32_t width, bool is_irrelevant) { |
| auto float_type_id = FindOrCreateFloatType(width); |
| if (auto constant_id = fuzzerutil::MaybeGetScalarConstant( |
| GetIRContext(), *GetTransformationContext(), words, float_type_id, |
| is_irrelevant)) { |
| return constant_id; |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddConstantScalar(result, float_type_id, |
| words, is_irrelevant)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateBoolConstant(bool value, bool is_irrelevant) { |
| auto bool_type_id = FindOrCreateBoolType(); |
| if (auto constant_id = fuzzerutil::MaybeGetScalarConstant( |
| GetIRContext(), *GetTransformationContext(), {value ? 1u : 0u}, |
| bool_type_id, is_irrelevant)) { |
| return constant_id; |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation( |
| TransformationAddConstantBoolean(result, value, is_irrelevant)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateConstant(const std::vector<uint32_t>& words, |
| uint32_t type_id, |
| bool is_irrelevant) { |
| assert(type_id && "Constant's type id can't be 0."); |
| |
| const auto* type = GetIRContext()->get_type_mgr()->GetType(type_id); |
| assert(type && "Type does not exist."); |
| |
| if (type->AsBool()) { |
| assert(words.size() == 1); |
| return FindOrCreateBoolConstant(words[0], is_irrelevant); |
| } else if (const auto* integer = type->AsInteger()) { |
| return FindOrCreateIntegerConstant(words, integer->width(), |
| integer->IsSigned(), is_irrelevant); |
| } else if (const auto* floating = type->AsFloat()) { |
| return FindOrCreateFloatConstant(words, floating->width(), is_irrelevant); |
| } |
| |
| // This assertion will fail in debug build but not in release build |
| // so we return 0 to make compiler happy. |
| assert(false && "Constant type is not supported"); |
| return 0; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateCompositeConstant( |
| const std::vector<uint32_t>& component_ids, uint32_t type_id, |
| bool is_irrelevant) { |
| if (auto existing_constant = fuzzerutil::MaybeGetCompositeConstant( |
| GetIRContext(), *GetTransformationContext(), component_ids, type_id, |
| is_irrelevant)) { |
| return existing_constant; |
| } |
| uint32_t result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddConstantComposite( |
| result, type_id, component_ids, is_irrelevant)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateGlobalUndef(uint32_t type_id) { |
| for (auto& inst : GetIRContext()->types_values()) { |
| if (inst.opcode() == SpvOpUndef && inst.type_id() == type_id) { |
| return inst.result_id(); |
| } |
| } |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddGlobalUndef(result, type_id)); |
| return result; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateNullConstant(uint32_t type_id) { |
| // Find existing declaration |
| opt::analysis::NullConstant null_constant( |
| GetIRContext()->get_type_mgr()->GetType(type_id)); |
| auto existing_constant = |
| GetIRContext()->get_constant_mgr()->FindConstant(&null_constant); |
| |
| // Return if found |
| if (existing_constant) { |
| return GetIRContext() |
| ->get_constant_mgr() |
| ->GetDefiningInstruction(existing_constant) |
| ->result_id(); |
| } |
| |
| // Create new if not found |
| auto result = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddConstantNull(result, type_id)); |
| return result; |
| } |
| |
| std::pair<std::vector<uint32_t>, std::map<uint32_t, std::vector<uint32_t>>> |
| FuzzerPass::GetAvailableBasicTypesAndPointers( |
| SpvStorageClass storage_class) const { |
| // Records all of the basic types available in the module. |
| std::set<uint32_t> basic_types; |
| |
| // For each basic type, records all the associated pointer types that target |
| // the basic type and that have |storage_class| as their storage class. |
| std::map<uint32_t, std::vector<uint32_t>> basic_type_to_pointers; |
| |
| for (auto& inst : GetIRContext()->types_values()) { |
| // For each basic type that we come across, record type, and the fact that |
| // we cannot yet have seen any pointers that use the basic type as its |
| // pointee type. |
| // |
| // For pointer types with basic pointee types, associate the pointer type |
| // with the basic type. |
| switch (inst.opcode()) { |
| case SpvOpTypeBool: |
| case SpvOpTypeFloat: |
| case SpvOpTypeInt: |
| case SpvOpTypeMatrix: |
| case SpvOpTypeVector: |
| // These are all basic types. |
| basic_types.insert(inst.result_id()); |
| basic_type_to_pointers.insert({inst.result_id(), {}}); |
| break; |
| case SpvOpTypeArray: |
| // An array type is basic if its base type is basic. |
| if (basic_types.count(inst.GetSingleWordInOperand(0))) { |
| basic_types.insert(inst.result_id()); |
| basic_type_to_pointers.insert({inst.result_id(), {}}); |
| } |
| break; |
| case SpvOpTypeStruct: { |
| // A struct type is basic if all of its members are basic. |
| bool all_members_are_basic_types = true; |
| for (uint32_t i = 0; i < inst.NumInOperands(); i++) { |
| if (!basic_types.count(inst.GetSingleWordInOperand(i))) { |
| all_members_are_basic_types = false; |
| break; |
| } |
| } |
| if (all_members_are_basic_types) { |
| basic_types.insert(inst.result_id()); |
| basic_type_to_pointers.insert({inst.result_id(), {}}); |
| } |
| break; |
| } |
| case SpvOpTypePointer: { |
| // We are interested in the pointer if its pointee type is basic and it |
| // has the right storage class. |
| auto pointee_type = inst.GetSingleWordInOperand(1); |
| if (inst.GetSingleWordInOperand(0) == storage_class && |
| basic_types.count(pointee_type)) { |
| // The pointer has the desired storage class, and its pointee type is |
| // a basic type, so we are interested in it. Associate it with its |
| // basic type. |
| basic_type_to_pointers.at(pointee_type).push_back(inst.result_id()); |
| } |
| break; |
| } |
| default: |
| break; |
| } |
| } |
| return {{basic_types.begin(), basic_types.end()}, basic_type_to_pointers}; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateZeroConstant( |
| uint32_t scalar_or_composite_type_id, bool is_irrelevant) { |
| auto type_instruction = |
| GetIRContext()->get_def_use_mgr()->GetDef(scalar_or_composite_type_id); |
| assert(type_instruction && "The type instruction must exist."); |
| switch (type_instruction->opcode()) { |
| case SpvOpTypeBool: |
| return FindOrCreateBoolConstant(false, is_irrelevant); |
| case SpvOpTypeFloat: { |
| auto width = type_instruction->GetSingleWordInOperand(0); |
| auto num_words = (width + 32 - 1) / 32; |
| return FindOrCreateFloatConstant(std::vector<uint32_t>(num_words, 0), |
| width, is_irrelevant); |
| } |
| case SpvOpTypeInt: { |
| auto width = type_instruction->GetSingleWordInOperand(0); |
| auto num_words = (width + 32 - 1) / 32; |
| return FindOrCreateIntegerConstant( |
| std::vector<uint32_t>(num_words, 0), width, |
| type_instruction->GetSingleWordInOperand(1), is_irrelevant); |
| } |
| case SpvOpTypeArray: { |
| auto component_type_id = type_instruction->GetSingleWordInOperand(0); |
| auto num_components = |
| fuzzerutil::GetArraySize(*type_instruction, GetIRContext()); |
| return FindOrCreateCompositeConstant( |
| std::vector<uint32_t>( |
| num_components, |
| FindOrCreateZeroConstant(component_type_id, is_irrelevant)), |
| scalar_or_composite_type_id, is_irrelevant); |
| } |
| case SpvOpTypeMatrix: |
| case SpvOpTypeVector: { |
| auto component_type_id = type_instruction->GetSingleWordInOperand(0); |
| auto num_components = type_instruction->GetSingleWordInOperand(1); |
| return FindOrCreateCompositeConstant( |
| std::vector<uint32_t>( |
| num_components, |
| FindOrCreateZeroConstant(component_type_id, is_irrelevant)), |
| scalar_or_composite_type_id, is_irrelevant); |
| } |
| case SpvOpTypeStruct: { |
| std::vector<uint32_t> field_zero_ids; |
| for (uint32_t index = 0; index < type_instruction->NumInOperands(); |
| index++) { |
| field_zero_ids.push_back(FindOrCreateZeroConstant( |
| type_instruction->GetSingleWordInOperand(index), is_irrelevant)); |
| } |
| return FindOrCreateCompositeConstant( |
| field_zero_ids, scalar_or_composite_type_id, is_irrelevant); |
| } |
| default: |
| assert(false && "Unknown type."); |
| return 0; |
| } |
| } |
| |
| void FuzzerPass::MaybeAddUseToReplace( |
| opt::Instruction* use_inst, uint32_t use_index, uint32_t replacement_id, |
| std::vector<std::pair<protobufs::IdUseDescriptor, uint32_t>>* |
| uses_to_replace) { |
| // Only consider this use if it is in a block |
| if (!GetIRContext()->get_instr_block(use_inst)) { |
| return; |
| } |
| |
| // Get the index of the operand restricted to input operands. |
| uint32_t in_operand_index = |
| fuzzerutil::InOperandIndexFromOperandIndex(*use_inst, use_index); |
| auto id_use_descriptor = |
| MakeIdUseDescriptorFromUse(GetIRContext(), use_inst, in_operand_index); |
| uses_to_replace->emplace_back( |
| std::make_pair(id_use_descriptor, replacement_id)); |
| } |
| |
| opt::BasicBlock* FuzzerPass::GetOrCreateSimpleLoopPreheader( |
| uint32_t header_id) { |
| auto header_block = fuzzerutil::MaybeFindBlock(GetIRContext(), header_id); |
| |
| assert(header_block && header_block->IsLoopHeader() && |
| "|header_id| should be the label id of a loop header"); |
| |
| auto predecessors = GetIRContext()->cfg()->preds(header_id); |
| |
| assert(predecessors.size() >= 2 && |
| "The block |header_id| should be reachable."); |
| |
| auto function = header_block->GetParent(); |
| |
| if (predecessors.size() == 2) { |
| // The header has a single out-of-loop predecessor, which could be a |
| // preheader. |
| |
| opt::BasicBlock* maybe_preheader; |
| |
| if (GetIRContext()->GetDominatorAnalysis(function)->Dominates( |
| header_id, predecessors[0])) { |
| // The first predecessor is the back-edge block, because the header |
| // dominates it, so the second one is out of the loop. |
| maybe_preheader = &*function->FindBlock(predecessors[1]); |
| } else { |
| // The first predecessor is out of the loop. |
| maybe_preheader = &*function->FindBlock(predecessors[0]); |
| } |
| |
| // |maybe_preheader| is a preheader if it branches unconditionally to |
| // the header. We also require it not to be a loop header. |
| if (maybe_preheader->terminator()->opcode() == SpvOpBranch && |
| !maybe_preheader->IsLoopHeader()) { |
| return maybe_preheader; |
| } |
| } |
| |
| // We need to add a preheader. |
| |
| // Get a fresh id for the preheader. |
| uint32_t preheader_id = GetFuzzerContext()->GetFreshId(); |
| |
| // Get a fresh id for each OpPhi instruction, if there is more than one |
| // out-of-loop predecessor. |
| std::vector<uint32_t> phi_ids; |
| if (predecessors.size() > 2) { |
| header_block->ForEachPhiInst( |
| [this, &phi_ids](opt::Instruction* /* unused */) { |
| phi_ids.push_back(GetFuzzerContext()->GetFreshId()); |
| }); |
| } |
| |
| // Add the preheader. |
| ApplyTransformation( |
| TransformationAddLoopPreheader(header_id, preheader_id, phi_ids)); |
| |
| // Make the newly-created preheader the new entry block. |
| return &*function->FindBlock(preheader_id); |
| } |
| |
| opt::BasicBlock* FuzzerPass::SplitBlockAfterOpPhiOrOpVariable( |
| uint32_t block_id) { |
| auto block = fuzzerutil::MaybeFindBlock(GetIRContext(), block_id); |
| assert(block && "|block_id| must be a block label"); |
| assert(!block->IsLoopHeader() && "|block_id| cannot be a loop header"); |
| |
| // Find the first non-OpPhi and non-OpVariable instruction. |
| auto non_phi_or_var_inst = &*block->begin(); |
| while (non_phi_or_var_inst->opcode() == SpvOpPhi || |
| non_phi_or_var_inst->opcode() == SpvOpVariable) { |
| non_phi_or_var_inst = non_phi_or_var_inst->NextNode(); |
| } |
| |
| // Split the block. |
| uint32_t new_block_id = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationSplitBlock( |
| MakeInstructionDescriptor(GetIRContext(), non_phi_or_var_inst), |
| new_block_id)); |
| |
| // We need to return the newly-created block. |
| return &*block->GetParent()->FindBlock(new_block_id); |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateLocalVariable( |
| uint32_t pointer_type_id, uint32_t function_id, |
| bool pointee_value_is_irrelevant) { |
| auto pointer_type = GetIRContext()->get_type_mgr()->GetType(pointer_type_id); |
| // No unused variables in release mode. |
| (void)pointer_type; |
| assert(pointer_type && pointer_type->AsPointer() && |
| pointer_type->AsPointer()->storage_class() == |
| SpvStorageClassFunction && |
| "The pointer_type_id must refer to a defined pointer type with " |
| "storage class Function"); |
| auto function = fuzzerutil::FindFunction(GetIRContext(), function_id); |
| assert(function && "The function must be defined."); |
| |
| // First we try to find a suitable existing variable. |
| // All of the local variable declarations are located in the first block. |
| for (auto& instruction : *function->begin()) { |
| if (instruction.opcode() != SpvOpVariable) { |
| continue; |
| } |
| // The existing OpVariable must have type |pointer_type_id|. |
| if (instruction.type_id() != pointer_type_id) { |
| continue; |
| } |
| // Check if the found variable is marked with PointeeValueIsIrrelevant |
| // according to |pointee_value_is_irrelevant|. |
| if (GetTransformationContext()->GetFactManager()->PointeeValueIsIrrelevant( |
| instruction.result_id()) != pointee_value_is_irrelevant) { |
| continue; |
| } |
| return instruction.result_id(); |
| } |
| |
| // No such variable was found. Apply a transformation to get one. |
| uint32_t pointee_type_id = fuzzerutil::GetPointeeTypeIdFromPointerType( |
| GetIRContext(), pointer_type_id); |
| uint32_t result_id = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddLocalVariable( |
| result_id, pointer_type_id, function_id, |
| FindOrCreateZeroConstant(pointee_type_id, pointee_value_is_irrelevant), |
| pointee_value_is_irrelevant)); |
| return result_id; |
| } |
| |
| uint32_t FuzzerPass::FindOrCreateGlobalVariable( |
| uint32_t pointer_type_id, bool pointee_value_is_irrelevant) { |
| auto pointer_type = GetIRContext()->get_type_mgr()->GetType(pointer_type_id); |
| // No unused variables in release mode. |
| (void)pointer_type; |
| assert( |
| pointer_type && pointer_type->AsPointer() && |
| (pointer_type->AsPointer()->storage_class() == SpvStorageClassPrivate || |
| pointer_type->AsPointer()->storage_class() == |
| SpvStorageClassWorkgroup) && |
| "The pointer_type_id must refer to a defined pointer type with storage " |
| "class Private or Workgroup"); |
| |
| // First we try to find a suitable existing variable. |
| for (auto& instruction : GetIRContext()->module()->types_values()) { |
| if (instruction.opcode() != SpvOpVariable) { |
| continue; |
| } |
| // The existing OpVariable must have type |pointer_type_id|. |
| if (instruction.type_id() != pointer_type_id) { |
| continue; |
| } |
| // Check if the found variable is marked with PointeeValueIsIrrelevant |
| // according to |pointee_value_is_irrelevant|. |
| if (GetTransformationContext()->GetFactManager()->PointeeValueIsIrrelevant( |
| instruction.result_id()) != pointee_value_is_irrelevant) { |
| continue; |
| } |
| return instruction.result_id(); |
| } |
| |
| // No such variable was found. Apply a transformation to get one. |
| uint32_t pointee_type_id = fuzzerutil::GetPointeeTypeIdFromPointerType( |
| GetIRContext(), pointer_type_id); |
| auto storage_class = fuzzerutil::GetStorageClassFromPointerType( |
| GetIRContext(), pointer_type_id); |
| uint32_t result_id = GetFuzzerContext()->GetFreshId(); |
| |
| // A variable with storage class Workgroup shouldn't have an initializer. |
| if (storage_class == SpvStorageClassWorkgroup) { |
| ApplyTransformation(TransformationAddGlobalVariable( |
| result_id, pointer_type_id, SpvStorageClassWorkgroup, 0, |
| pointee_value_is_irrelevant)); |
| } else { |
| ApplyTransformation(TransformationAddGlobalVariable( |
| result_id, pointer_type_id, SpvStorageClassPrivate, |
| FindOrCreateZeroConstant(pointee_type_id, pointee_value_is_irrelevant), |
| pointee_value_is_irrelevant)); |
| } |
| return result_id; |
| } |
| |
| } // namespace fuzz |
| } // namespace spvtools |
