SPIRV-Tools/source/fuzz/fuzzer_pass_copy_objects.cpp
Alastair Donaldson 00170cc5e6
spirv-fuzz: Refactor 'copy object' and 'construct composite' transformations (#2966)
Rework these transformations to identify instructions via (base,
opcode, skip-count) triples, rather than (base, offset) pairs.
2019-10-15 20:00:17 +01:00

81 lines
3.2 KiB
C++

// 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_copy_objects.h"
#include "source/fuzz/fuzzer_util.h"
#include "source/fuzz/transformation_copy_object.h"
namespace spvtools {
namespace fuzz {
FuzzerPassCopyObjects::FuzzerPassCopyObjects(
opt::IRContext* ir_context, FactManager* fact_manager,
FuzzerContext* fuzzer_context,
protobufs::TransformationSequence* transformations)
: FuzzerPass(ir_context, fact_manager, fuzzer_context, transformations) {}
FuzzerPassCopyObjects::~FuzzerPassCopyObjects() = default;
void FuzzerPassCopyObjects::Apply() {
MaybeAddTransformationBeforeEachInstruction(
[this](const opt::Function& function, opt::BasicBlock* block,
opt::BasicBlock::iterator inst_it,
const protobufs::InstructionDescriptor& instruction_descriptor)
-> void {
assert(inst_it->opcode() ==
instruction_descriptor.target_instruction_opcode() &&
"The opcode of the instruction we might insert before must be "
"the same as the opcode in the descriptor for the instruction");
// Check whether it is legitimate to insert a copy before this
// instruction.
if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(SpvOpCopyObject,
inst_it)) {
return;
}
// Randomly decide whether to try inserting an object copy here.
if (!GetFuzzerContext()->ChoosePercentage(
GetFuzzerContext()->GetChanceOfCopyingObject())) {
return;
}
std::vector<opt::Instruction*> relevant_instructions =
FindAvailableInstructions(function, block, inst_it,
fuzzerutil::CanMakeSynonymOf);
// At this point, |relevant_instructions| contains all the instructions
// we might think of copying.
if (relevant_instructions.empty()) {
return;
}
// Choose a copyable instruction at random, and create and apply an
// object copying transformation based on it.
uint32_t index = GetFuzzerContext()->RandomIndex(relevant_instructions);
TransformationCopyObject transformation(
relevant_instructions[index]->result_id(), instruction_descriptor,
GetFuzzerContext()->GetFreshId());
assert(transformation.IsApplicable(GetIRContext(), *GetFactManager()) &&
"This transformation should be applicable by construction.");
transformation.Apply(GetIRContext(), GetFactManager());
*GetTransformations()->add_transformation() =
transformation.ToMessage();
});
}
} // namespace fuzz
} // namespace spvtools