SPIRV-Tools/source/fuzz/fuzzer_pass_add_global_variables.cpp
Alastair Donaldson 1f03ac1027
spirv-fuzz: Fuzzer passes to add local and global variables (#3175)
Adds two new fuzzer passes to add variables to a module: one that adds
Private storage class global variables, another that adds Function
storage class local variables.
2020-02-05 21:07:44 +00:00

76 lines
3.1 KiB
C++

// 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_global_variables.h"
#include "source/fuzz/transformation_add_global_variable.h"
#include "source/fuzz/transformation_add_type_pointer.h"
namespace spvtools {
namespace fuzz {
FuzzerPassAddGlobalVariables::FuzzerPassAddGlobalVariables(
opt::IRContext* ir_context, FactManager* fact_manager,
FuzzerContext* fuzzer_context,
protobufs::TransformationSequence* transformations)
: FuzzerPass(ir_context, fact_manager, fuzzer_context, transformations) {}
FuzzerPassAddGlobalVariables::~FuzzerPassAddGlobalVariables() = default;
void FuzzerPassAddGlobalVariables::Apply() {
auto base_type_ids_and_pointers =
GetAvailableBaseTypesAndPointers(SpvStorageClassPrivate);
// These are the base types that are available to this fuzzer pass.
auto& base_types = base_type_ids_and_pointers.first;
// These are the pointers to those base 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 base type.
auto& base_type_to_pointers = base_type_ids_and_pointers.second;
// Probabilistically keep adding global variables.
while (GetFuzzerContext()->ChoosePercentage(
GetFuzzerContext()->GetChanceOfAddingGlobalVariable())) {
// Choose a random base type; the new variable's type will be a pointer to
// this base type.
uint32_t base_type =
base_types[GetFuzzerContext()->RandomIndex(base_types)];
uint32_t pointer_type_id;
std::vector<uint32_t>& available_pointers_to_base_type =
base_type_to_pointers.at(base_type);
// Determine whether there is at least one pointer to this base type.
if (available_pointers_to_base_type.empty()) {
// There is not. Make one, to use here, and add it to the available
// pointers for the base type so that future variables can potentially
// use it.
pointer_type_id = GetFuzzerContext()->GetFreshId();
available_pointers_to_base_type.push_back(pointer_type_id);
ApplyTransformation(TransformationAddTypePointer(
pointer_type_id, SpvStorageClassPrivate, base_type));
} else {
// There is - grab one.
pointer_type_id =
available_pointers_to_base_type[GetFuzzerContext()->RandomIndex(
available_pointers_to_base_type)];
}
ApplyTransformation(TransformationAddGlobalVariable(
GetFuzzerContext()->GetFreshId(), pointer_type_id,
FindOrCreateZeroConstant(base_type), true));
}
}
} // namespace fuzz
} // namespace spvtools