SPIRV-Tools/source/fuzz/fuzzer_pass_add_bit_instruction_synonyms.cpp
Alastair Donaldson bcf5b211db
spirv-fuzz: Add support for reining in rogue fuzzer passes (#3987)
Adds some functions that allow a fuzzer pass to check whether it is
spiralling out of control and exit early.  The fuzzer pass for adding
bit instruction synonyms now uses this.  Also make many methods in
FuzzerContext const.
2020-11-03 16:51:10 +00:00

93 lines
3.5 KiB
C++

// Copyright (c) 2020 André Perez Maselco
//
// 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_bit_instruction_synonyms.h"
#include "source/fuzz/fuzzer_util.h"
#include "source/fuzz/instruction_descriptor.h"
#include "source/fuzz/transformation_add_bit_instruction_synonym.h"
namespace spvtools {
namespace fuzz {
FuzzerPassAddBitInstructionSynonyms::FuzzerPassAddBitInstructionSynonyms(
opt::IRContext* ir_context, TransformationContext* transformation_context,
FuzzerContext* fuzzer_context,
protobufs::TransformationSequence* transformations)
: FuzzerPass(ir_context, transformation_context, fuzzer_context,
transformations) {}
FuzzerPassAddBitInstructionSynonyms::~FuzzerPassAddBitInstructionSynonyms() =
default;
void FuzzerPassAddBitInstructionSynonyms::Apply() {
for (auto& function : *GetIRContext()->module()) {
for (auto& block : function) {
for (auto& instruction : block) {
// This fuzzer pass can add a *lot* of ids. We bail out early if we hit
// the recommended id limit.
if (GetIRContext()->module()->id_bound() >=
GetFuzzerContext()->GetIdBoundLimit()) {
return;
}
// Randomly decides whether the transformation will be applied.
if (!GetFuzzerContext()->ChoosePercentage(
GetFuzzerContext()->GetChanceOfAddingBitInstructionSynonym())) {
continue;
}
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3557):
// Right now we only support certain operations. When this issue is
// addressed the following conditional can use the function
// |spvOpcodeIsBit|.
if (instruction.opcode() != SpvOpBitwiseOr &&
instruction.opcode() != SpvOpBitwiseXor &&
instruction.opcode() != SpvOpBitwiseAnd &&
instruction.opcode() != SpvOpNot) {
continue;
}
// Right now, only integer operands are supported.
if (GetIRContext()
->get_type_mgr()
->GetType(instruction.type_id())
->AsVector()) {
continue;
}
// Make sure all bit indexes are defined as 32-bit unsigned integers.
uint32_t width = GetIRContext()
->get_type_mgr()
->GetType(instruction.type_id())
->AsInteger()
->width();
for (uint32_t i = 0; i < width; i++) {
FindOrCreateIntegerConstant({i}, 32, false, false);
}
// Applies the add bit instruction synonym transformation.
ApplyTransformation(TransformationAddBitInstructionSynonym(
instruction.result_id(),
GetFuzzerContext()->GetFreshIds(
TransformationAddBitInstructionSynonym::GetRequiredFreshIdCount(
GetIRContext(), &instruction))));
}
}
}
}
} // namespace fuzz
} // namespace spvtools