| // 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/fuzzer_pass_add_local_variables.h" |
| |
| #include "source/fuzz/fuzzer_util.h" |
| #include "source/fuzz/transformation_add_local_variable.h" |
| #include "source/fuzz/transformation_add_type_pointer.h" |
| |
| namespace spvtools { |
| namespace fuzz { |
| |
| FuzzerPassAddLocalVariables::FuzzerPassAddLocalVariables( |
| opt::IRContext* ir_context, TransformationContext* transformation_context, |
| FuzzerContext* fuzzer_context, |
| protobufs::TransformationSequence* transformations, |
| bool ignore_inapplicable_transformations) |
| : FuzzerPass(ir_context, transformation_context, fuzzer_context, |
| transformations, ignore_inapplicable_transformations) {} |
| |
| void FuzzerPassAddLocalVariables::Apply() { |
| auto basic_type_ids_and_pointers = |
| GetAvailableBasicTypesAndPointers(SpvStorageClassFunction); |
| |
| // These are the basic types that are available to this fuzzer pass. |
| auto& basic_types = basic_type_ids_and_pointers.first; |
| if (basic_types.empty()) { |
| // The pass cannot do anything if there are no basic types. |
| return; |
| } |
| |
| // These are the pointers to those basic types that are *initially* available |
| // to the fuzzer pass. The fuzzer pass might add pointer types in cases where |
| // none are available for a given basic type. |
| auto& basic_type_to_pointers = basic_type_ids_and_pointers.second; |
| |
| // Consider every function in the module. |
| for (auto& function : *GetIRContext()->module()) { |
| // Probabilistically keep adding random variables to this function. |
| while (GetFuzzerContext()->ChoosePercentage( |
| GetFuzzerContext()->GetChanceOfAddingLocalVariable())) { |
| // Choose a random basic type; the new variable's type will be a pointer |
| // to this basic type. |
| uint32_t basic_type = |
| basic_types[GetFuzzerContext()->RandomIndex(basic_types)]; |
| uint32_t pointer_type; |
| std::vector<uint32_t>& available_pointers_to_basic_type = |
| basic_type_to_pointers.at(basic_type); |
| // Determine whether there is at least one pointer to this basic type. |
| if (available_pointers_to_basic_type.empty()) { |
| // There is not. Make one, to use here, and add it to the available |
| // pointers for the basic type so that future variables can potentially |
| // use it. |
| pointer_type = GetFuzzerContext()->GetFreshId(); |
| ApplyTransformation(TransformationAddTypePointer( |
| pointer_type, SpvStorageClassFunction, basic_type)); |
| available_pointers_to_basic_type.push_back(pointer_type); |
| } else { |
| // There is - grab one. |
| pointer_type = |
| available_pointers_to_basic_type[GetFuzzerContext()->RandomIndex( |
| available_pointers_to_basic_type)]; |
| } |
| ApplyTransformation(TransformationAddLocalVariable( |
| GetFuzzerContext()->GetFreshId(), pointer_type, function.result_id(), |
| FindOrCreateZeroConstant(basic_type, false), true)); |
| } |
| } |
| } |
| |
| } // namespace fuzz |
| } // namespace spvtools |