SPIRV-Tools/source/fuzz/transformation_merge_blocks.cpp
Alastair Donaldson 8d4261bc44
spirv-fuzz: Introduce TransformationContext (#3272)
Some transformations (e.g. TransformationAddFunction) rely on running
the validator to decide whether the transformation is applicable.  A
recent change allowed spirv-fuzz to take validator options, to cater
for the case where a module should be considered valid under
particular conditions.  However, validation during the checking of
transformations had no access to these validator options.

This change introduced TransformationContext, which currently consists
of a fact manager and a set of validator options, but could in the
future have other fields corresponding to other objects that it is
useful to have access to when applying transformations.  Now, instead
of checking and applying transformations in the context of a
FactManager, a TransformationContext is used.  This gives access to
the fact manager as before, and also access to the validator options
when they are needed.
2020-04-02 15:54:46 +01:00

83 lines
3.0 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/transformation_merge_blocks.h"
#include "source/fuzz/fuzzer_util.h"
#include "source/opt/block_merge_util.h"
namespace spvtools {
namespace fuzz {
TransformationMergeBlocks::TransformationMergeBlocks(
const spvtools::fuzz::protobufs::TransformationMergeBlocks& message)
: message_(message) {}
TransformationMergeBlocks::TransformationMergeBlocks(uint32_t block_id) {
message_.set_block_id(block_id);
}
bool TransformationMergeBlocks::IsApplicable(
opt::IRContext* ir_context, const TransformationContext& /*unused*/) const {
auto second_block =
fuzzerutil::MaybeFindBlock(ir_context, message_.block_id());
// The given block must exist.
if (!second_block) {
return false;
}
// The block must have just one predecessor.
auto predecessors = ir_context->cfg()->preds(second_block->id());
if (predecessors.size() != 1) {
return false;
}
auto first_block = ir_context->cfg()->block(predecessors.at(0));
return opt::blockmergeutil::CanMergeWithSuccessor(ir_context, first_block);
}
void TransformationMergeBlocks::Apply(opt::IRContext* ir_context,
TransformationContext* /*unused*/) const {
auto second_block =
fuzzerutil::MaybeFindBlock(ir_context, message_.block_id());
auto first_block = ir_context->cfg()->block(
ir_context->cfg()->preds(second_block->id()).at(0));
auto function = first_block->GetParent();
// We need an iterator pointing to the predecessor, hence the loop.
for (auto bi = function->begin(); bi != function->end(); ++bi) {
if (bi->id() == first_block->id()) {
assert(opt::blockmergeutil::CanMergeWithSuccessor(ir_context, &*bi) &&
"Because 'Apply' should only be invoked if 'IsApplicable' holds, "
"it must be possible to merge |bi| with its successor.");
opt::blockmergeutil::MergeWithSuccessor(ir_context, function, bi);
// Invalidate all analyses, since we have changed the module
// significantly.
ir_context->InvalidateAnalysesExceptFor(opt::IRContext::kAnalysisNone);
return;
}
}
assert(false &&
"Control should not reach here - we should always find the desired "
"block");
}
protobufs::Transformation TransformationMergeBlocks::ToMessage() const {
protobufs::Transformation result;
*result.mutable_merge_blocks() = message_;
return result;
}
} // namespace fuzz
} // namespace spvtools