SPIRV-Tools/source/fuzz/fuzzer_pass_copy_objects.cpp

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// 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/protobufs/spirvfuzz_protobufs.h"
#include "source/fuzz/transformation_add_synonym.h"
namespace spvtools {
namespace fuzz {
FuzzerPassCopyObjects::FuzzerPassCopyObjects(
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 FuzzerPassCopyObjects::Apply() {
ForEachInstructionWithInstructionDescriptor(
[this](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");
if (GetTransformationContext()->GetFactManager()->BlockIsDead(
block->id())) {
// Don't create synonyms in dead blocks.
return;
}
// 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;
}
const auto relevant_instructions = FindAvailableInstructions(
function, block, inst_it,
[this](opt::IRContext* ir_context, opt::Instruction* inst) {
return TransformationAddSynonym::IsInstructionValid(
ir_context, *GetTransformationContext(), inst,
protobufs::TransformationAddSynonym::COPY_OBJECT);
});
// 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.
ApplyTransformation(TransformationAddSynonym(
relevant_instructions[GetFuzzerContext()->RandomIndex(
relevant_instructions)]
->result_id(),
protobufs::TransformationAddSynonym::COPY_OBJECT,
GetFuzzerContext()->GetFreshId(), instruction_descriptor));
});
}
} // namespace fuzz
} // namespace spvtools