SPIRV-Tools/source/fuzz/transformation_replace_id_with_synonym.h
Stefano Milizia 3daabd3212
spirv-fuzz: Transformation to replace the use of an irrelevant id (#3697)
A transformation that replaces the use of an irrelevant id with
another id of the same type.

The related fuzzer pass, for every use of an irrelevant id,
checks whether the id can be replaced in that use by another
id of the same type and randomly decides whether to replace
it.

Fixes #3503.
2020-09-01 16:28:04 +01:00

76 lines
3.1 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.
#ifndef SOURCE_FUZZ_TRANSFORMATION_REPLACE_ID_WITH_SYNONYM_H_
#define SOURCE_FUZZ_TRANSFORMATION_REPLACE_ID_WITH_SYNONYM_H_
#include "source/fuzz/protobufs/spirvfuzz_protobufs.h"
#include "source/fuzz/transformation.h"
#include "source/fuzz/transformation_context.h"
#include "source/opt/ir_context.h"
namespace spvtools {
namespace fuzz {
class TransformationReplaceIdWithSynonym : public Transformation {
public:
explicit TransformationReplaceIdWithSynonym(
const protobufs::TransformationReplaceIdWithSynonym& message);
TransformationReplaceIdWithSynonym(
protobufs::IdUseDescriptor id_use_descriptor, uint32_t synonymous_id);
// - The fact manager must know that the id identified by
// |message_.id_use_descriptor| is synonomous with |message_.synonymous_id|.
// - Replacing the id in |message_.id_use_descriptor| by
// |message_.synonymous_id| must respect SPIR-V's rules about uses being
// dominated by their definitions.
// - The id use must be replaceable in principle. See
// fuzzerutil::IdUseCanBeReplaced for details.
// - |fresh_id_for_temporary| must be 0.
bool IsApplicable(
opt::IRContext* ir_context,
const TransformationContext& transformation_context) const override;
// Replaces the use identified by |message_.id_use_descriptor| with the
// synonymous id identified by |message_.synonymous_id|.
void Apply(opt::IRContext* ir_context,
TransformationContext* transformation_context) const override;
protobufs::Transformation ToMessage() const override;
// Returns true if |type_id_1| and |type_id_2| represent compatible types
// given the context of the instruction with |opcode| (i.e. we can replace
// an operand of |opcode| of the first type with an id of the second type
// and vice-versa).
static bool TypesAreCompatible(opt::IRContext* ir_context, SpvOp opcode,
uint32_t use_in_operand_index,
uint32_t type_id_1, uint32_t type_id_2);
private:
// Returns true if the instruction with opcode |opcode| does not change its
// behaviour depending on the signedness of the operand at
// |use_in_operand_index|.
// Assumes that the operand must be the id of an integer scalar or vector.
static bool IsAgnosticToSignednessOfOperand(SpvOp opcode,
uint32_t use_in_operand_index);
protobufs::TransformationReplaceIdWithSynonym message_;
};
} // namespace fuzz
} // namespace spvtools
#endif // SOURCE_FUZZ_TRANSFORMATION_REPLACE_ID_WITH_SYNONYM_H_