SPIRV-Tools/source/fuzz/transformation_replace_id_with_synonym.h
Alastair Donaldson fe10239f92
spirv-fuzz: Add fuzzer passes to add loads/stores (#3176)
This change adds fuzzer passes that sprinkle loads and stores into a
module at random, with stores restricted to occur in either dead
blocks, or to use pointers for which it is known that the pointee
value does not influence the module's overall behaviour.

The change also generalises the VariableValueIsArbitrary fact to
PointeeValueIsIrrelevant, to allow stores through access chains or
object copies of variables whose values are known to be irrelevant.

The change includes some other minor refactorings.
2020-02-06 16:54:34 +00:00

73 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/fact_manager.h"
#include "source/fuzz/protobufs/spirvfuzz_protobufs.h"
#include "source/fuzz/transformation.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 must not be an index into an access chain whose base object has
// struct type, as such indices must be constants.
// - The id must not be a pointer argument to a function call (because the
// synonym might not be a memory object declaration).
// - |fresh_id_for_temporary| must be 0.
bool IsApplicable(opt::IRContext* context,
const FactManager& fact_manager) const override;
// Replaces the use identified by |message_.id_use_descriptor| with the
// synonymous id identified by |message_.synonymous_id|.
void Apply(opt::IRContext* context, FactManager* fact_manager) const override;
protobufs::Transformation ToMessage() const override;
// Checks whether various conditions hold related to the acceptability of
// replacing the id use at |use_in_operand_index| of |use_instruction| with
// a synonym. In particular, this checks that:
// - the id use is not an index into a struct field in an OpAccessChain - such
// indices must be constants, so it is dangerous to replace them.
// - the id use is not a pointer function call argument, on which there are
// restrictions that make replacement problematic.
static bool UseCanBeReplacedWithSynonym(opt::IRContext* context,
opt::Instruction* use_instruction,
uint32_t use_in_operand_index);
private:
protobufs::TransformationReplaceIdWithSynonym message_;
};
} // namespace fuzz
} // namespace spvtools
#endif // SOURCE_FUZZ_TRANSFORMATION_REPLACE_ID_WITH_SYNONYM_H_