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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/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(spv::StorageClass::Function);
// 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, spv::StorageClass::Function, 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
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