SPIRV-Tools/source/fuzz/transformation_load.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

103 lines
3.7 KiB
C++

// Copyright (c) 2020 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_load.h"
#include "source/fuzz/fuzzer_util.h"
#include "source/fuzz/instruction_descriptor.h"
namespace spvtools {
namespace fuzz {
TransformationLoad::TransformationLoad(
const spvtools::fuzz::protobufs::TransformationLoad& message)
: message_(message) {}
TransformationLoad::TransformationLoad(
uint32_t fresh_id, uint32_t pointer_id,
const protobufs::InstructionDescriptor& instruction_to_insert_before) {
message_.set_fresh_id(fresh_id);
message_.set_pointer_id(pointer_id);
*message_.mutable_instruction_to_insert_before() =
instruction_to_insert_before;
}
bool TransformationLoad::IsApplicable(
opt::IRContext* ir_context, const TransformationContext& /*unused*/) const {
// The result id must be fresh.
if (!fuzzerutil::IsFreshId(ir_context, message_.fresh_id())) {
return false;
}
// The pointer must exist and have a type.
auto pointer = ir_context->get_def_use_mgr()->GetDef(message_.pointer_id());
if (!pointer || !pointer->type_id()) {
return false;
}
// The type must indeed be a pointer type.
auto pointer_type = ir_context->get_def_use_mgr()->GetDef(pointer->type_id());
assert(pointer_type && "Type id must be defined.");
if (pointer_type->opcode() != SpvOpTypePointer) {
return false;
}
// We do not want to allow loading from null or undefined pointers, as it is
// not clear how punishing the consequences of doing so are from a semantics
// point of view.
switch (pointer->opcode()) {
case SpvOpConstantNull:
case SpvOpUndef:
return false;
default:
break;
}
// Determine which instruction we should be inserting before.
auto insert_before =
FindInstruction(message_.instruction_to_insert_before(), ir_context);
// It must exist, ...
if (!insert_before) {
return false;
}
// ... and it must be legitimate to insert a store before it.
if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(SpvOpLoad, insert_before)) {
return false;
}
// The pointer needs to be available at the insertion point.
return fuzzerutil::IdIsAvailableBeforeInstruction(ir_context, insert_before,
message_.pointer_id());
}
void TransformationLoad::Apply(opt::IRContext* ir_context,
TransformationContext* /*unused*/) const {
uint32_t result_type = fuzzerutil::GetPointeeTypeIdFromPointerType(
ir_context, fuzzerutil::GetTypeId(ir_context, message_.pointer_id()));
fuzzerutil::UpdateModuleIdBound(ir_context, message_.fresh_id());
FindInstruction(message_.instruction_to_insert_before(), ir_context)
->InsertBefore(MakeUnique<opt::Instruction>(
ir_context, SpvOpLoad, result_type, message_.fresh_id(),
opt::Instruction::OperandList(
{{SPV_OPERAND_TYPE_ID, {message_.pointer_id()}}})));
ir_context->InvalidateAnalysesExceptFor(opt::IRContext::kAnalysisNone);
}
protobufs::Transformation TransformationLoad::ToMessage() const {
protobufs::Transformation result;
*result.mutable_load() = message_;
return result;
}
} // namespace fuzz
} // namespace spvtools