mirror of
https://github.com/KhronosGroup/SPIRV-Tools
synced 2024-12-27 02:10:15 +00:00
c0833ce620
Subclasses of FuzzerPass no longer needlessly override the default destructor of FuzzerPass.
78 lines
2.8 KiB
C++
78 lines
2.8 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_permute_blocks.h"
|
|
|
|
#include "source/fuzz/transformation_move_block_down.h"
|
|
|
|
namespace spvtools {
|
|
namespace fuzz {
|
|
|
|
FuzzerPassPermuteBlocks::FuzzerPassPermuteBlocks(
|
|
opt::IRContext* ir_context, TransformationContext* transformation_context,
|
|
FuzzerContext* fuzzer_context,
|
|
protobufs::TransformationSequence* transformations)
|
|
: FuzzerPass(ir_context, transformation_context, fuzzer_context,
|
|
transformations) {}
|
|
|
|
void FuzzerPassPermuteBlocks::Apply() {
|
|
// For now we do something very simple: we randomly decide whether to move a
|
|
// block, and for each block that we do move, we push it down as far as we
|
|
// legally can.
|
|
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/2635): it would be
|
|
// nice to randomly sample from the set of legal block permutations and then
|
|
// encode the chosen permutation via a series of move-block-down
|
|
// transformations. This should be possible but will require some thought.
|
|
|
|
for (auto& function : *GetIRContext()->module()) {
|
|
std::vector<uint32_t> block_ids;
|
|
// Collect all block ids for the function before messing with block
|
|
// ordering.
|
|
for (auto& block : function) {
|
|
block_ids.push_back(block.id());
|
|
}
|
|
// Now consider each block id. We consider block ids in reverse, because
|
|
// e.g. in code generated from the following:
|
|
//
|
|
// if (...) {
|
|
// A
|
|
// B
|
|
// } else {
|
|
// C
|
|
// }
|
|
//
|
|
// block A cannot be moved down, but B has freedom to move and that movement
|
|
// would provide more freedom for A to move.
|
|
for (auto id = block_ids.rbegin(); id != block_ids.rend(); ++id) {
|
|
// Randomly decide whether to ignore the block id.
|
|
if (!GetFuzzerContext()->ChoosePercentage(
|
|
GetFuzzerContext()->GetChanceOfMovingBlockDown())) {
|
|
continue;
|
|
}
|
|
// Keep pushing the block down, until pushing down fails.
|
|
// The loop is guaranteed to terminate because a block cannot be pushed
|
|
// down indefinitely.
|
|
while (true) {
|
|
TransformationMoveBlockDown transformation(*id);
|
|
if (!MaybeApplyTransformation(transformation)) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
} // namespace fuzz
|
|
} // namespace spvtools
|