mirror of
https://github.com/KhronosGroup/SPIRV-Tools
synced 2024-12-27 02:10:15 +00:00
a02a9205ff
There are some edge cases where adding livesafe functions does not succeed, due to loop limiter edges breaking SPIR-V dominance rules. As these edge cases are rare it does not seem worth implementing complex additional logic to handle all cases. This change accepts that trying to add a function in a livesafe manner may not succeed.
1215 lines
54 KiB
C++
1215 lines
54 KiB
C++
// Copyright (c) 2019 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "source/fuzz/fuzzer_pass_donate_modules.h"
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#include <map>
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#include <queue>
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#include <set>
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#include "source/fuzz/call_graph.h"
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#include "source/fuzz/instruction_message.h"
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#include "source/fuzz/transformation_add_constant_boolean.h"
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#include "source/fuzz/transformation_add_constant_composite.h"
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#include "source/fuzz/transformation_add_constant_null.h"
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#include "source/fuzz/transformation_add_constant_scalar.h"
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#include "source/fuzz/transformation_add_function.h"
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#include "source/fuzz/transformation_add_global_undef.h"
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#include "source/fuzz/transformation_add_global_variable.h"
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#include "source/fuzz/transformation_add_spec_constant_op.h"
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#include "source/fuzz/transformation_add_type_array.h"
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#include "source/fuzz/transformation_add_type_boolean.h"
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#include "source/fuzz/transformation_add_type_float.h"
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#include "source/fuzz/transformation_add_type_function.h"
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#include "source/fuzz/transformation_add_type_int.h"
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#include "source/fuzz/transformation_add_type_matrix.h"
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#include "source/fuzz/transformation_add_type_pointer.h"
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#include "source/fuzz/transformation_add_type_struct.h"
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#include "source/fuzz/transformation_add_type_vector.h"
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namespace spvtools {
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namespace fuzz {
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FuzzerPassDonateModules::FuzzerPassDonateModules(
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opt::IRContext* ir_context, TransformationContext* transformation_context,
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FuzzerContext* fuzzer_context,
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protobufs::TransformationSequence* transformations,
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const std::vector<fuzzerutil::ModuleSupplier>& donor_suppliers)
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: FuzzerPass(ir_context, transformation_context, fuzzer_context,
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transformations),
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donor_suppliers_(donor_suppliers) {}
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void FuzzerPassDonateModules::Apply() {
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// If there are no donor suppliers, this fuzzer pass is a no-op.
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if (donor_suppliers_.empty()) {
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return;
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}
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// Donate at least one module, and probabilistically decide when to stop
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// donating modules.
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do {
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// Choose a donor supplier at random, and get the module that it provides.
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std::unique_ptr<opt::IRContext> donor_ir_context = donor_suppliers_.at(
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GetFuzzerContext()->RandomIndex(donor_suppliers_))();
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assert(donor_ir_context != nullptr && "Supplying of donor failed");
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assert(
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fuzzerutil::IsValid(donor_ir_context.get(),
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GetTransformationContext()->GetValidatorOptions(),
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fuzzerutil::kSilentMessageConsumer) &&
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"The donor module must be valid");
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// Donate the supplied module.
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//
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// Randomly decide whether to make the module livesafe (see
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// FactFunctionIsLivesafe); doing so allows it to be used for live code
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// injection but restricts its behaviour to allow this, and means that its
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// functions cannot be transformed as if they were arbitrary dead code.
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bool make_livesafe = GetFuzzerContext()->ChoosePercentage(
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GetFuzzerContext()->ChanceOfMakingDonorLivesafe());
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DonateSingleModule(donor_ir_context.get(), make_livesafe);
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} while (GetFuzzerContext()->ChoosePercentage(
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GetFuzzerContext()->GetChanceOfDonatingAdditionalModule()));
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}
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void FuzzerPassDonateModules::DonateSingleModule(
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opt::IRContext* donor_ir_context, bool make_livesafe) {
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// Check that the donated module has capabilities, supported by the recipient
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// module.
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for (const auto& capability_inst : donor_ir_context->capabilities()) {
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auto capability =
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static_cast<SpvCapability>(capability_inst.GetSingleWordInOperand(0));
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if (!GetIRContext()->get_feature_mgr()->HasCapability(capability)) {
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return;
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}
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}
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// The ids used by the donor module may very well clash with ids defined in
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// the recipient module. Furthermore, some instructions defined in the donor
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// module will be equivalent to instructions defined in the recipient module,
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// and it is not always legal to re-declare equivalent instructions. For
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// example, OpTypeVoid cannot be declared twice.
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//
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// To handle this, we maintain a mapping from an id used in the donor module
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// to the corresponding id that will be used by the donated code when it
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// appears in the recipient module.
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//
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// This mapping is populated in two ways:
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// (1) by mapping a donor instruction's result id to the id of some equivalent
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// existing instruction in the recipient (e.g. this has to be done for
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// OpTypeVoid)
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// (2) by mapping a donor instruction's result id to a freshly chosen id that
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// is guaranteed to be different from any id already used by the recipient
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// (or from any id already chosen to handle a previous donor id)
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std::map<uint32_t, uint32_t> original_id_to_donated_id;
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HandleExternalInstructionImports(donor_ir_context,
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&original_id_to_donated_id);
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HandleTypesAndValues(donor_ir_context, &original_id_to_donated_id);
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HandleFunctions(donor_ir_context, &original_id_to_donated_id, make_livesafe);
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// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3115) Handle some
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// kinds of decoration.
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}
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SpvStorageClass FuzzerPassDonateModules::AdaptStorageClass(
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SpvStorageClass donor_storage_class) {
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switch (donor_storage_class) {
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case SpvStorageClassFunction:
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case SpvStorageClassPrivate:
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case SpvStorageClassWorkgroup:
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// We leave these alone
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return donor_storage_class;
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case SpvStorageClassInput:
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case SpvStorageClassOutput:
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case SpvStorageClassUniform:
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case SpvStorageClassUniformConstant:
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case SpvStorageClassPushConstant:
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case SpvStorageClassImage:
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case SpvStorageClassStorageBuffer:
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// We change these to Private
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return SpvStorageClassPrivate;
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default:
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// Handle other cases on demand.
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assert(false && "Currently unsupported storage class.");
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return SpvStorageClassMax;
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}
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}
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void FuzzerPassDonateModules::HandleExternalInstructionImports(
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opt::IRContext* donor_ir_context,
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std::map<uint32_t, uint32_t>* original_id_to_donated_id) {
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// Consider every external instruction set import in the donor module.
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for (auto& donor_import : donor_ir_context->module()->ext_inst_imports()) {
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const auto& donor_import_name_words = donor_import.GetInOperand(0).words;
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// Look for an identical import in the recipient module.
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for (auto& existing_import : GetIRContext()->module()->ext_inst_imports()) {
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const auto& existing_import_name_words =
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existing_import.GetInOperand(0).words;
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if (donor_import_name_words == existing_import_name_words) {
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// A matching import has found. Map the result id for the donor import
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// to the id of the existing import, so that when donor instructions
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// rely on the import they will be rewritten to use the existing import.
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original_id_to_donated_id->insert(
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{donor_import.result_id(), existing_import.result_id()});
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break;
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}
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}
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// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3116): At present
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// we do not handle donation of instruction imports, i.e. we do not allow
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// the donor to import instruction sets that the recipient did not already
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// import. It might be a good idea to allow this, but it requires some
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// thought.
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assert(original_id_to_donated_id->count(donor_import.result_id()) &&
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"Donation of imports is not yet supported.");
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}
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}
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void FuzzerPassDonateModules::HandleTypesAndValues(
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opt::IRContext* donor_ir_context,
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std::map<uint32_t, uint32_t>* original_id_to_donated_id) {
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// Consider every type/global/constant/undef in the module.
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for (auto& type_or_value : donor_ir_context->module()->types_values()) {
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HandleTypeOrValue(type_or_value, original_id_to_donated_id);
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}
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}
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void FuzzerPassDonateModules::HandleTypeOrValue(
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const opt::Instruction& type_or_value,
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std::map<uint32_t, uint32_t>* original_id_to_donated_id) {
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// The type/value instruction generates a result id, and we need to associate
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// the donor's result id with a new result id. That new result id will either
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// be the id of some existing instruction, or a fresh id. This variable
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// captures it.
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uint32_t new_result_id;
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// Decide how to handle each kind of instruction on a case-by-case basis.
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//
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// Because the donor module is required to be valid, when we encounter a
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// type comprised of component types (e.g. an aggregate or pointer), we know
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// that its component types will have been considered previously, and that
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// |original_id_to_donated_id| will already contain an entry for them.
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switch (type_or_value.opcode()) {
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case SpvOpTypeImage:
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case SpvOpTypeSampledImage:
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case SpvOpTypeSampler:
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// We do not donate types and variables that relate to images and
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// samplers, so we skip these types and subsequently skip anything that
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// depends on them.
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return;
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case SpvOpTypeVoid: {
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// Void has to exist already in order for us to have an entry point.
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// Get the existing id of void.
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opt::analysis::Void void_type;
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new_result_id = GetIRContext()->get_type_mgr()->GetId(&void_type);
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assert(new_result_id &&
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"The module being transformed will always have 'void' type "
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"declared.");
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} break;
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case SpvOpTypeBool: {
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// Bool cannot be declared multiple times, so use its existing id if
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// present, or add a declaration of Bool with a fresh id if not.
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opt::analysis::Bool bool_type;
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auto bool_type_id = GetIRContext()->get_type_mgr()->GetId(&bool_type);
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if (bool_type_id) {
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new_result_id = bool_type_id;
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} else {
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new_result_id = GetFuzzerContext()->GetFreshId();
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ApplyTransformation(TransformationAddTypeBoolean(new_result_id));
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}
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} break;
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case SpvOpTypeInt: {
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// Int cannot be declared multiple times with the same width and
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// signedness, so check whether an existing identical Int type is
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// present and use its id if so. Otherwise add a declaration of the
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// Int type used by the donor, with a fresh id.
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const uint32_t width = type_or_value.GetSingleWordInOperand(0);
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const bool is_signed =
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static_cast<bool>(type_or_value.GetSingleWordInOperand(1));
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opt::analysis::Integer int_type(width, is_signed);
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auto int_type_id = GetIRContext()->get_type_mgr()->GetId(&int_type);
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if (int_type_id) {
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new_result_id = int_type_id;
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} else {
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new_result_id = GetFuzzerContext()->GetFreshId();
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ApplyTransformation(
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TransformationAddTypeInt(new_result_id, width, is_signed));
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}
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} break;
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case SpvOpTypeFloat: {
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// Similar to SpvOpTypeInt.
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const uint32_t width = type_or_value.GetSingleWordInOperand(0);
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opt::analysis::Float float_type(width);
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auto float_type_id = GetIRContext()->get_type_mgr()->GetId(&float_type);
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if (float_type_id) {
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new_result_id = float_type_id;
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} else {
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new_result_id = GetFuzzerContext()->GetFreshId();
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ApplyTransformation(TransformationAddTypeFloat(new_result_id, width));
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}
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} break;
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case SpvOpTypeVector: {
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// It is not legal to have two Vector type declarations with identical
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// element types and element counts, so check whether an existing
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// identical Vector type is present and use its id if so. Otherwise add
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// a declaration of the Vector type used by the donor, with a fresh id.
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// When considering the vector's component type id, we look up the id
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// use in the donor to find the id to which this has been remapped.
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uint32_t component_type_id = original_id_to_donated_id->at(
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type_or_value.GetSingleWordInOperand(0));
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auto component_type =
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GetIRContext()->get_type_mgr()->GetType(component_type_id);
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assert(component_type && "The base type should be registered.");
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auto component_count = type_or_value.GetSingleWordInOperand(1);
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opt::analysis::Vector vector_type(component_type, component_count);
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auto vector_type_id = GetIRContext()->get_type_mgr()->GetId(&vector_type);
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if (vector_type_id) {
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new_result_id = vector_type_id;
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} else {
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new_result_id = GetFuzzerContext()->GetFreshId();
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ApplyTransformation(TransformationAddTypeVector(
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new_result_id, component_type_id, component_count));
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}
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} break;
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case SpvOpTypeMatrix: {
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// Similar to SpvOpTypeVector.
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uint32_t column_type_id = original_id_to_donated_id->at(
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type_or_value.GetSingleWordInOperand(0));
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auto column_type =
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GetIRContext()->get_type_mgr()->GetType(column_type_id);
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assert(column_type && column_type->AsVector() &&
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"The column type should be a registered vector type.");
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auto column_count = type_or_value.GetSingleWordInOperand(1);
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opt::analysis::Matrix matrix_type(column_type, column_count);
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auto matrix_type_id = GetIRContext()->get_type_mgr()->GetId(&matrix_type);
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if (matrix_type_id) {
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new_result_id = matrix_type_id;
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} else {
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new_result_id = GetFuzzerContext()->GetFreshId();
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ApplyTransformation(TransformationAddTypeMatrix(
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new_result_id, column_type_id, column_count));
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}
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} break;
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case SpvOpTypeArray: {
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// It is OK to have multiple structurally identical array types, so
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// we go ahead and add a remapped version of the type declared by the
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// donor.
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uint32_t component_type_id = type_or_value.GetSingleWordInOperand(0);
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if (!original_id_to_donated_id->count(component_type_id)) {
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// We did not donate the component type of this array type, so we
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// cannot donate the array type.
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return;
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}
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new_result_id = GetFuzzerContext()->GetFreshId();
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ApplyTransformation(TransformationAddTypeArray(
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new_result_id, original_id_to_donated_id->at(component_type_id),
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original_id_to_donated_id->at(
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type_or_value.GetSingleWordInOperand(1))));
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} break;
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case SpvOpTypeRuntimeArray: {
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// A runtime array is allowed as the final member of an SSBO. During
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// donation we turn runtime arrays into fixed-size arrays. For dead
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// code donations this is OK because the array is never indexed into at
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// runtime, so it does not matter what its size is. For live-safe code,
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// all accesses are made in-bounds, so this is also OK.
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//
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// The special OpArrayLength instruction, which works on runtime arrays,
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// is rewritten to yield the fixed length that is used for the array.
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uint32_t component_type_id = type_or_value.GetSingleWordInOperand(0);
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if (!original_id_to_donated_id->count(component_type_id)) {
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// We did not donate the component type of this runtime array type, so
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// we cannot donate it as a fixed-size array.
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return;
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}
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new_result_id = GetFuzzerContext()->GetFreshId();
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ApplyTransformation(TransformationAddTypeArray(
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new_result_id, original_id_to_donated_id->at(component_type_id),
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FindOrCreateIntegerConstant(
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{GetFuzzerContext()->GetRandomSizeForNewArray()}, 32, false,
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false)));
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} break;
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case SpvOpTypeStruct: {
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// Similar to SpvOpTypeArray.
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std::vector<uint32_t> member_type_ids;
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for (uint32_t i = 0; i < type_or_value.NumInOperands(); i++) {
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auto component_type_id = type_or_value.GetSingleWordInOperand(i);
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if (!original_id_to_donated_id->count(component_type_id)) {
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// We did not donate every member type for this struct type, so we
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// cannot donate the struct type.
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return;
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}
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member_type_ids.push_back(
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original_id_to_donated_id->at(component_type_id));
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}
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new_result_id = GetFuzzerContext()->GetFreshId();
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ApplyTransformation(
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TransformationAddTypeStruct(new_result_id, member_type_ids));
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} break;
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case SpvOpTypePointer: {
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// Similar to SpvOpTypeArray.
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uint32_t pointee_type_id = type_or_value.GetSingleWordInOperand(1);
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if (!original_id_to_donated_id->count(pointee_type_id)) {
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// We did not donate the pointee type for this pointer type, so we
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// cannot donate the pointer type.
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return;
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}
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new_result_id = GetFuzzerContext()->GetFreshId();
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ApplyTransformation(TransformationAddTypePointer(
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new_result_id,
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AdaptStorageClass(static_cast<SpvStorageClass>(
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type_or_value.GetSingleWordInOperand(0))),
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original_id_to_donated_id->at(pointee_type_id)));
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} break;
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case SpvOpTypeFunction: {
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// It is not OK to have multiple function types that use identical ids
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// for their return and parameter types. We thus go through all
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// existing function types to look for a match. We do not use the
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// type manager here because we want to regard two function types that
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// are structurally identical but that differ with respect to the
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// actual ids used for pointer types as different.
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//
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// Example:
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//
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// %1 = OpTypeVoid
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// %2 = OpTypeInt 32 0
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// %3 = OpTypePointer Function %2
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// %4 = OpTypePointer Function %2
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// %5 = OpTypeFunction %1 %3
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// %6 = OpTypeFunction %1 %4
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//
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// We regard %5 and %6 as distinct function types here, even though
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// they both have the form "uint32* -> void"
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std::vector<uint32_t> return_and_parameter_types;
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for (uint32_t i = 0; i < type_or_value.NumInOperands(); i++) {
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uint32_t return_or_parameter_type =
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type_or_value.GetSingleWordInOperand(i);
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if (!original_id_to_donated_id->count(return_or_parameter_type)) {
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// We did not donate every return/parameter type for this function
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// type, so we cannot donate the function type.
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return;
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}
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return_and_parameter_types.push_back(
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original_id_to_donated_id->at(return_or_parameter_type));
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}
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uint32_t existing_function_id = fuzzerutil::FindFunctionType(
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GetIRContext(), return_and_parameter_types);
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if (existing_function_id) {
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new_result_id = existing_function_id;
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} else {
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// No match was found, so add a remapped version of the function type
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// to the module, with a fresh id.
|
|
new_result_id = GetFuzzerContext()->GetFreshId();
|
|
std::vector<uint32_t> argument_type_ids;
|
|
for (uint32_t i = 1; i < type_or_value.NumInOperands(); i++) {
|
|
argument_type_ids.push_back(original_id_to_donated_id->at(
|
|
type_or_value.GetSingleWordInOperand(i)));
|
|
}
|
|
ApplyTransformation(TransformationAddTypeFunction(
|
|
new_result_id,
|
|
original_id_to_donated_id->at(
|
|
type_or_value.GetSingleWordInOperand(0)),
|
|
argument_type_ids));
|
|
}
|
|
} break;
|
|
case SpvOpSpecConstantOp: {
|
|
new_result_id = GetFuzzerContext()->GetFreshId();
|
|
auto type_id = original_id_to_donated_id->at(type_or_value.type_id());
|
|
auto opcode = static_cast<SpvOp>(type_or_value.GetSingleWordInOperand(0));
|
|
|
|
// Make sure we take into account |original_id_to_donated_id| when
|
|
// computing operands for OpSpecConstantOp.
|
|
opt::Instruction::OperandList operands;
|
|
for (uint32_t i = 1; i < type_or_value.NumInOperands(); ++i) {
|
|
const auto& operand = type_or_value.GetInOperand(i);
|
|
auto data =
|
|
operand.type == SPV_OPERAND_TYPE_ID
|
|
? opt::Operand::OperandData{original_id_to_donated_id->at(
|
|
operand.words[0])}
|
|
: operand.words;
|
|
|
|
operands.push_back({operand.type, std::move(data)});
|
|
}
|
|
|
|
ApplyTransformation(TransformationAddSpecConstantOp(
|
|
new_result_id, type_id, opcode, std::move(operands)));
|
|
} break;
|
|
case SpvOpSpecConstantTrue:
|
|
case SpvOpSpecConstantFalse:
|
|
case SpvOpConstantTrue:
|
|
case SpvOpConstantFalse: {
|
|
// It is OK to have duplicate definitions of True and False, so add
|
|
// these to the module, using a remapped Bool type.
|
|
new_result_id = GetFuzzerContext()->GetFreshId();
|
|
auto value = type_or_value.opcode() == SpvOpConstantTrue ||
|
|
type_or_value.opcode() == SpvOpSpecConstantTrue;
|
|
ApplyTransformation(
|
|
TransformationAddConstantBoolean(new_result_id, value, false));
|
|
} break;
|
|
case SpvOpSpecConstant:
|
|
case SpvOpConstant: {
|
|
// It is OK to have duplicate constant definitions, so add this to the
|
|
// module using a remapped result type.
|
|
new_result_id = GetFuzzerContext()->GetFreshId();
|
|
std::vector<uint32_t> data_words;
|
|
type_or_value.ForEachInOperand([&data_words](const uint32_t* in_operand) {
|
|
data_words.push_back(*in_operand);
|
|
});
|
|
ApplyTransformation(TransformationAddConstantScalar(
|
|
new_result_id, original_id_to_donated_id->at(type_or_value.type_id()),
|
|
data_words, false));
|
|
} break;
|
|
case SpvOpSpecConstantComposite:
|
|
case SpvOpConstantComposite: {
|
|
assert(original_id_to_donated_id->count(type_or_value.type_id()) &&
|
|
"Composite types for which it is possible to create a constant "
|
|
"should have been donated.");
|
|
|
|
// It is OK to have duplicate constant composite definitions, so add
|
|
// this to the module using remapped versions of all consituent ids and
|
|
// the result type.
|
|
new_result_id = GetFuzzerContext()->GetFreshId();
|
|
std::vector<uint32_t> constituent_ids;
|
|
type_or_value.ForEachInId([&constituent_ids, &original_id_to_donated_id](
|
|
const uint32_t* constituent_id) {
|
|
assert(original_id_to_donated_id->count(*constituent_id) &&
|
|
"The constants used to construct this composite should "
|
|
"have been donated.");
|
|
constituent_ids.push_back(
|
|
original_id_to_donated_id->at(*constituent_id));
|
|
});
|
|
ApplyTransformation(TransformationAddConstantComposite(
|
|
new_result_id, original_id_to_donated_id->at(type_or_value.type_id()),
|
|
constituent_ids, false));
|
|
} break;
|
|
case SpvOpConstantNull: {
|
|
if (!original_id_to_donated_id->count(type_or_value.type_id())) {
|
|
// We did not donate the type associated with this null constant, so
|
|
// we cannot donate the null constant.
|
|
return;
|
|
}
|
|
|
|
// It is fine to have multiple OpConstantNull instructions of the same
|
|
// type, so we just add this to the recipient module.
|
|
new_result_id = GetFuzzerContext()->GetFreshId();
|
|
ApplyTransformation(TransformationAddConstantNull(
|
|
new_result_id,
|
|
original_id_to_donated_id->at(type_or_value.type_id())));
|
|
} break;
|
|
case SpvOpVariable: {
|
|
if (!original_id_to_donated_id->count(type_or_value.type_id())) {
|
|
// We did not donate the pointer type associated with this variable,
|
|
// so we cannot donate the variable.
|
|
return;
|
|
}
|
|
|
|
// This is a global variable that could have one of various storage
|
|
// classes. However, we change all global variable pointer storage
|
|
// classes (such as Uniform, Input and Output) to private when donating
|
|
// pointer types, with the exception of the Workgroup storage class.
|
|
//
|
|
// Thus this variable's pointer type is guaranteed to have storage class
|
|
// Private or Workgroup.
|
|
//
|
|
// We add a global variable with either Private or Workgroup storage
|
|
// class, using remapped versions of the result type and initializer ids
|
|
// for the global variable in the donor.
|
|
//
|
|
// We regard the added variable as having an irrelevant value. This
|
|
// means that future passes can add stores to the variable in any
|
|
// way they wish, and pass them as pointer parameters to functions
|
|
// without worrying about whether their data might get modified.
|
|
new_result_id = GetFuzzerContext()->GetFreshId();
|
|
uint32_t remapped_pointer_type =
|
|
original_id_to_donated_id->at(type_or_value.type_id());
|
|
uint32_t initializer_id;
|
|
SpvStorageClass storage_class =
|
|
static_cast<SpvStorageClass>(type_or_value.GetSingleWordInOperand(
|
|
0)) == SpvStorageClassWorkgroup
|
|
? SpvStorageClassWorkgroup
|
|
: SpvStorageClassPrivate;
|
|
if (type_or_value.NumInOperands() == 1) {
|
|
// The variable did not have an initializer. Initialize it to zero
|
|
// if it has Private storage class (to limit problems associated with
|
|
// uninitialized data), and leave it uninitialized if it has Workgroup
|
|
// storage class (as Workgroup variables cannot have initializers).
|
|
|
|
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3275): we
|
|
// could initialize Workgroup variables at the start of an entry
|
|
// point, and should do so if their uninitialized nature proves
|
|
// problematic.
|
|
initializer_id = storage_class == SpvStorageClassWorkgroup
|
|
? 0
|
|
: FindOrCreateZeroConstant(
|
|
fuzzerutil::GetPointeeTypeIdFromPointerType(
|
|
GetIRContext(), remapped_pointer_type),
|
|
false);
|
|
} else {
|
|
// The variable already had an initializer; use its remapped id.
|
|
initializer_id = original_id_to_donated_id->at(
|
|
type_or_value.GetSingleWordInOperand(1));
|
|
}
|
|
ApplyTransformation(
|
|
TransformationAddGlobalVariable(new_result_id, remapped_pointer_type,
|
|
storage_class, initializer_id, true));
|
|
} break;
|
|
case SpvOpUndef: {
|
|
if (!original_id_to_donated_id->count(type_or_value.type_id())) {
|
|
// We did not donate the type associated with this undef, so we cannot
|
|
// donate the undef.
|
|
return;
|
|
}
|
|
|
|
// It is fine to have multiple Undef instructions of the same type, so
|
|
// we just add this to the recipient module.
|
|
new_result_id = GetFuzzerContext()->GetFreshId();
|
|
ApplyTransformation(TransformationAddGlobalUndef(
|
|
new_result_id,
|
|
original_id_to_donated_id->at(type_or_value.type_id())));
|
|
} break;
|
|
default: {
|
|
assert(0 && "Unknown type/value.");
|
|
new_result_id = 0;
|
|
} break;
|
|
}
|
|
|
|
// Update the id mapping to associate the instruction's result id with its
|
|
// corresponding id in the recipient.
|
|
original_id_to_donated_id->insert({type_or_value.result_id(), new_result_id});
|
|
}
|
|
|
|
void FuzzerPassDonateModules::HandleFunctions(
|
|
opt::IRContext* donor_ir_context,
|
|
std::map<uint32_t, uint32_t>* original_id_to_donated_id,
|
|
bool make_livesafe) {
|
|
// Get the ids of functions in the donor module, topologically sorted
|
|
// according to the donor's call graph.
|
|
auto topological_order =
|
|
CallGraph(donor_ir_context).GetFunctionsInTopologicalOrder();
|
|
|
|
// Donate the functions in reverse topological order. This ensures that a
|
|
// function gets donated before any function that depends on it. This allows
|
|
// donation of the functions to be separated into a number of transformations,
|
|
// each adding one function, such that every prefix of transformations leaves
|
|
// the module valid.
|
|
for (auto function_id = topological_order.rbegin();
|
|
function_id != topological_order.rend(); ++function_id) {
|
|
// Find the function to be donated.
|
|
opt::Function* function_to_donate = nullptr;
|
|
for (auto& function : *donor_ir_context->module()) {
|
|
if (function.result_id() == *function_id) {
|
|
function_to_donate = &function;
|
|
break;
|
|
}
|
|
}
|
|
assert(function_to_donate && "Function to be donated was not found.");
|
|
|
|
if (!original_id_to_donated_id->count(
|
|
function_to_donate->DefInst().GetSingleWordInOperand(1))) {
|
|
// We were not able to donate this function's type, so we cannot donate
|
|
// the function.
|
|
continue;
|
|
}
|
|
|
|
// We will collect up protobuf messages representing the donor function's
|
|
// instructions here, and use them to create an AddFunction transformation.
|
|
std::vector<protobufs::Instruction> donated_instructions;
|
|
|
|
// This set tracks the ids of those instructions for which donation was
|
|
// completely skipped: neither the instruction nor a substitute for it was
|
|
// donated.
|
|
std::set<uint32_t> skipped_instructions;
|
|
|
|
// Consider every instruction of the donor function.
|
|
function_to_donate->ForEachInst(
|
|
[this, &donated_instructions, donor_ir_context,
|
|
&original_id_to_donated_id,
|
|
&skipped_instructions](const opt::Instruction* instruction) {
|
|
if (instruction->opcode() == SpvOpArrayLength) {
|
|
// We treat OpArrayLength specially.
|
|
HandleOpArrayLength(*instruction, original_id_to_donated_id,
|
|
&donated_instructions);
|
|
} else if (!CanDonateInstruction(donor_ir_context, *instruction,
|
|
*original_id_to_donated_id,
|
|
skipped_instructions)) {
|
|
// This is an instruction that we cannot directly donate.
|
|
HandleDifficultInstruction(*instruction, original_id_to_donated_id,
|
|
&donated_instructions,
|
|
&skipped_instructions);
|
|
} else {
|
|
PrepareInstructionForDonation(*instruction, donor_ir_context,
|
|
original_id_to_donated_id,
|
|
&donated_instructions);
|
|
}
|
|
});
|
|
|
|
// If |make_livesafe| is true, try to add the function in a livesafe manner.
|
|
// Otherwise (if |make_lifesafe| is false or an attempt to make the function
|
|
// livesafe has failed), add the function in a non-livesafe manner.
|
|
if (!make_livesafe ||
|
|
!MaybeAddLivesafeFunction(*function_to_donate, donor_ir_context,
|
|
*original_id_to_donated_id,
|
|
donated_instructions)) {
|
|
ApplyTransformation(TransformationAddFunction(donated_instructions));
|
|
}
|
|
}
|
|
}
|
|
|
|
bool FuzzerPassDonateModules::CanDonateInstruction(
|
|
opt::IRContext* donor_ir_context, const opt::Instruction& instruction,
|
|
const std::map<uint32_t, uint32_t>& original_id_to_donated_id,
|
|
const std::set<uint32_t>& skipped_instructions) const {
|
|
if (instruction.type_id() &&
|
|
!original_id_to_donated_id.count(instruction.type_id())) {
|
|
// We could not donate the result type of this instruction, so we cannot
|
|
// donate the instruction.
|
|
return false;
|
|
}
|
|
|
|
// Now consider instructions we specifically want to skip because we do not
|
|
// yet support them.
|
|
switch (instruction.opcode()) {
|
|
case SpvOpAtomicLoad:
|
|
case SpvOpAtomicStore:
|
|
case SpvOpAtomicExchange:
|
|
case SpvOpAtomicCompareExchange:
|
|
case SpvOpAtomicCompareExchangeWeak:
|
|
case SpvOpAtomicIIncrement:
|
|
case SpvOpAtomicIDecrement:
|
|
case SpvOpAtomicIAdd:
|
|
case SpvOpAtomicISub:
|
|
case SpvOpAtomicSMin:
|
|
case SpvOpAtomicUMin:
|
|
case SpvOpAtomicSMax:
|
|
case SpvOpAtomicUMax:
|
|
case SpvOpAtomicAnd:
|
|
case SpvOpAtomicOr:
|
|
case SpvOpAtomicXor:
|
|
// We conservatively ignore all atomic instructions at present.
|
|
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3276): Consider
|
|
// being less conservative here.
|
|
case SpvOpImageSampleImplicitLod:
|
|
case SpvOpImageSampleExplicitLod:
|
|
case SpvOpImageSampleDrefImplicitLod:
|
|
case SpvOpImageSampleDrefExplicitLod:
|
|
case SpvOpImageSampleProjImplicitLod:
|
|
case SpvOpImageSampleProjExplicitLod:
|
|
case SpvOpImageSampleProjDrefImplicitLod:
|
|
case SpvOpImageSampleProjDrefExplicitLod:
|
|
case SpvOpImageFetch:
|
|
case SpvOpImageGather:
|
|
case SpvOpImageDrefGather:
|
|
case SpvOpImageRead:
|
|
case SpvOpImageWrite:
|
|
case SpvOpImageSparseSampleImplicitLod:
|
|
case SpvOpImageSparseSampleExplicitLod:
|
|
case SpvOpImageSparseSampleDrefImplicitLod:
|
|
case SpvOpImageSparseSampleDrefExplicitLod:
|
|
case SpvOpImageSparseSampleProjImplicitLod:
|
|
case SpvOpImageSparseSampleProjExplicitLod:
|
|
case SpvOpImageSparseSampleProjDrefImplicitLod:
|
|
case SpvOpImageSparseSampleProjDrefExplicitLod:
|
|
case SpvOpImageSparseFetch:
|
|
case SpvOpImageSparseGather:
|
|
case SpvOpImageSparseDrefGather:
|
|
case SpvOpImageSparseRead:
|
|
case SpvOpImageSampleFootprintNV:
|
|
case SpvOpImage:
|
|
case SpvOpImageQueryFormat:
|
|
case SpvOpImageQueryLevels:
|
|
case SpvOpImageQueryLod:
|
|
case SpvOpImageQueryOrder:
|
|
case SpvOpImageQuerySamples:
|
|
case SpvOpImageQuerySize:
|
|
case SpvOpImageQuerySizeLod:
|
|
case SpvOpSampledImage:
|
|
// We ignore all instructions related to accessing images, since we do not
|
|
// donate images.
|
|
return false;
|
|
case SpvOpLoad:
|
|
switch (donor_ir_context->get_def_use_mgr()
|
|
->GetDef(instruction.type_id())
|
|
->opcode()) {
|
|
case SpvOpTypeImage:
|
|
case SpvOpTypeSampledImage:
|
|
case SpvOpTypeSampler:
|
|
// Again, we ignore instructions that relate to accessing images.
|
|
return false;
|
|
default:
|
|
break;
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
|
|
// Examine each id input operand to the instruction. If it turns out that we
|
|
// have skipped any of these operands then we cannot donate the instruction.
|
|
bool result = true;
|
|
instruction.WhileEachInId(
|
|
[donor_ir_context, &original_id_to_donated_id, &result,
|
|
&skipped_instructions](const uint32_t* in_id) -> bool {
|
|
if (!original_id_to_donated_id.count(*in_id)) {
|
|
// We do not have a mapped result id for this id operand. That either
|
|
// means that it is a forward reference (which is OK), that we skipped
|
|
// the instruction that generated it (which is not OK), or that it is
|
|
// the id of a function or global value that we did not donate (which
|
|
// is not OK). We check for the latter two cases.
|
|
if (skipped_instructions.count(*in_id) ||
|
|
// A function or global value does not have an associated basic
|
|
// block.
|
|
!donor_ir_context->get_instr_block(*in_id)) {
|
|
result = false;
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
});
|
|
return result;
|
|
}
|
|
|
|
bool FuzzerPassDonateModules::IsBasicType(
|
|
const opt::Instruction& instruction) const {
|
|
switch (instruction.opcode()) {
|
|
case SpvOpTypeArray:
|
|
case SpvOpTypeBool:
|
|
case SpvOpTypeFloat:
|
|
case SpvOpTypeInt:
|
|
case SpvOpTypeMatrix:
|
|
case SpvOpTypeStruct:
|
|
case SpvOpTypeVector:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
void FuzzerPassDonateModules::HandleOpArrayLength(
|
|
const opt::Instruction& instruction,
|
|
std::map<uint32_t, uint32_t>* original_id_to_donated_id,
|
|
std::vector<protobufs::Instruction>* donated_instructions) const {
|
|
assert(instruction.opcode() == SpvOpArrayLength &&
|
|
"Precondition: instruction must be OpArrayLength.");
|
|
uint32_t donated_variable_id =
|
|
original_id_to_donated_id->at(instruction.GetSingleWordInOperand(0));
|
|
auto donated_variable_instruction =
|
|
GetIRContext()->get_def_use_mgr()->GetDef(donated_variable_id);
|
|
auto pointer_to_struct_instruction =
|
|
GetIRContext()->get_def_use_mgr()->GetDef(
|
|
donated_variable_instruction->type_id());
|
|
assert(pointer_to_struct_instruction->opcode() == SpvOpTypePointer &&
|
|
"Type of variable must be pointer.");
|
|
auto donated_struct_type_instruction =
|
|
GetIRContext()->get_def_use_mgr()->GetDef(
|
|
pointer_to_struct_instruction->GetSingleWordInOperand(1));
|
|
assert(donated_struct_type_instruction->opcode() == SpvOpTypeStruct &&
|
|
"Pointee type of pointer used by OpArrayLength must be struct.");
|
|
assert(donated_struct_type_instruction->NumInOperands() ==
|
|
instruction.GetSingleWordInOperand(1) + 1 &&
|
|
"OpArrayLength must refer to the final member of the given "
|
|
"struct.");
|
|
uint32_t fixed_size_array_type_id =
|
|
donated_struct_type_instruction->GetSingleWordInOperand(
|
|
donated_struct_type_instruction->NumInOperands() - 1);
|
|
auto fixed_size_array_type_instruction =
|
|
GetIRContext()->get_def_use_mgr()->GetDef(fixed_size_array_type_id);
|
|
assert(fixed_size_array_type_instruction->opcode() == SpvOpTypeArray &&
|
|
"The donated array type must be fixed-size.");
|
|
auto array_size_id =
|
|
fixed_size_array_type_instruction->GetSingleWordInOperand(1);
|
|
|
|
if (instruction.result_id() &&
|
|
!original_id_to_donated_id->count(instruction.result_id())) {
|
|
original_id_to_donated_id->insert(
|
|
{instruction.result_id(), GetFuzzerContext()->GetFreshId()});
|
|
}
|
|
|
|
donated_instructions->push_back(MakeInstructionMessage(
|
|
SpvOpCopyObject, original_id_to_donated_id->at(instruction.type_id()),
|
|
original_id_to_donated_id->at(instruction.result_id()),
|
|
opt::Instruction::OperandList({{SPV_OPERAND_TYPE_ID, {array_size_id}}})));
|
|
}
|
|
|
|
void FuzzerPassDonateModules::HandleDifficultInstruction(
|
|
const opt::Instruction& instruction,
|
|
std::map<uint32_t, uint32_t>* original_id_to_donated_id,
|
|
std::vector<protobufs::Instruction>* donated_instructions,
|
|
std::set<uint32_t>* skipped_instructions) {
|
|
if (!instruction.result_id()) {
|
|
// It does not generate a result id, so it can be ignored.
|
|
return;
|
|
}
|
|
if (!original_id_to_donated_id->count(instruction.type_id())) {
|
|
// We cannot handle this instruction's result type, so we need to skip it
|
|
// all together.
|
|
skipped_instructions->insert(instruction.result_id());
|
|
return;
|
|
}
|
|
|
|
// We now attempt to replace the instruction with an OpCopyObject.
|
|
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3278): We could do
|
|
// something more refined here - we could check which operands to the
|
|
// instruction could not be donated and replace those operands with
|
|
// references to other ids (such as constants), so that we still get an
|
|
// instruction with the opcode and easy-to-handle operands of the donor
|
|
// instruction.
|
|
auto remapped_type_id = original_id_to_donated_id->at(instruction.type_id());
|
|
if (!IsBasicType(
|
|
*GetIRContext()->get_def_use_mgr()->GetDef(remapped_type_id))) {
|
|
// The instruction has a non-basic result type, so we cannot replace it with
|
|
// an object copy of a constant. We thus skip it completely.
|
|
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3279): We could
|
|
// instead look for an available id of the right type and generate an
|
|
// OpCopyObject of that id.
|
|
skipped_instructions->insert(instruction.result_id());
|
|
return;
|
|
}
|
|
|
|
// We are going to add an OpCopyObject instruction. Add a mapping for the
|
|
// result id of the original instruction if does not already exist (it may
|
|
// exist in the case that it has been forward-referenced).
|
|
if (!original_id_to_donated_id->count(instruction.result_id())) {
|
|
original_id_to_donated_id->insert(
|
|
{instruction.result_id(), GetFuzzerContext()->GetFreshId()});
|
|
}
|
|
|
|
// We find or add a zero constant to the receiving module for the type in
|
|
// question, and add an OpCopyObject instruction that copies this zero.
|
|
//
|
|
// We mark the constant as irrelevant so that we can replace it with a
|
|
// more interesting value later.
|
|
auto zero_constant = FindOrCreateZeroConstant(remapped_type_id, true);
|
|
donated_instructions->push_back(MakeInstructionMessage(
|
|
SpvOpCopyObject, remapped_type_id,
|
|
original_id_to_donated_id->at(instruction.result_id()),
|
|
opt::Instruction::OperandList({{SPV_OPERAND_TYPE_ID, {zero_constant}}})));
|
|
}
|
|
|
|
void FuzzerPassDonateModules::PrepareInstructionForDonation(
|
|
const opt::Instruction& instruction, opt::IRContext* donor_ir_context,
|
|
std::map<uint32_t, uint32_t>* original_id_to_donated_id,
|
|
std::vector<protobufs::Instruction>* donated_instructions) {
|
|
// Get the instruction's input operands into donation-ready form,
|
|
// remapping any id uses in the process.
|
|
opt::Instruction::OperandList input_operands;
|
|
|
|
// Consider each input operand in turn.
|
|
for (uint32_t in_operand_index = 0;
|
|
in_operand_index < instruction.NumInOperands(); in_operand_index++) {
|
|
std::vector<uint32_t> operand_data;
|
|
const opt::Operand& in_operand = instruction.GetInOperand(in_operand_index);
|
|
// Check whether this operand is an id.
|
|
if (spvIsIdType(in_operand.type)) {
|
|
// This is an id operand - it consists of a single word of data,
|
|
// which needs to be remapped so that it is replaced with the
|
|
// donated form of the id.
|
|
auto operand_id = in_operand.words[0];
|
|
if (!original_id_to_donated_id->count(operand_id)) {
|
|
// This is a forward reference. We will choose a corresponding
|
|
// donor id for the referenced id and update the mapping to
|
|
// reflect it.
|
|
|
|
// Keep release compilers happy because |donor_ir_context| is only used
|
|
// in this assertion.
|
|
(void)(donor_ir_context);
|
|
assert((donor_ir_context->get_def_use_mgr()
|
|
->GetDef(operand_id)
|
|
->opcode() == SpvOpLabel ||
|
|
instruction.opcode() == SpvOpPhi) &&
|
|
"Unsupported forward reference.");
|
|
original_id_to_donated_id->insert(
|
|
{operand_id, GetFuzzerContext()->GetFreshId()});
|
|
}
|
|
operand_data.push_back(original_id_to_donated_id->at(operand_id));
|
|
} else {
|
|
// For non-id operands, we just add each of the data words.
|
|
for (auto word : in_operand.words) {
|
|
operand_data.push_back(word);
|
|
}
|
|
}
|
|
input_operands.push_back({in_operand.type, operand_data});
|
|
}
|
|
|
|
if (instruction.opcode() == SpvOpVariable &&
|
|
instruction.NumInOperands() == 1) {
|
|
// This is an uninitialized local variable. Initialize it to zero.
|
|
input_operands.push_back(
|
|
{SPV_OPERAND_TYPE_ID,
|
|
{FindOrCreateZeroConstant(
|
|
fuzzerutil::GetPointeeTypeIdFromPointerType(
|
|
GetIRContext(),
|
|
original_id_to_donated_id->at(instruction.type_id())),
|
|
false)}});
|
|
}
|
|
|
|
if (instruction.result_id() &&
|
|
!original_id_to_donated_id->count(instruction.result_id())) {
|
|
original_id_to_donated_id->insert(
|
|
{instruction.result_id(), GetFuzzerContext()->GetFreshId()});
|
|
}
|
|
|
|
// Remap the result type and result id (if present) of the
|
|
// instruction, and turn it into a protobuf message.
|
|
donated_instructions->push_back(MakeInstructionMessage(
|
|
instruction.opcode(),
|
|
instruction.type_id()
|
|
? original_id_to_donated_id->at(instruction.type_id())
|
|
: 0,
|
|
instruction.result_id()
|
|
? original_id_to_donated_id->at(instruction.result_id())
|
|
: 0,
|
|
input_operands));
|
|
}
|
|
|
|
bool FuzzerPassDonateModules::CreateLoopLimiterInfo(
|
|
opt::IRContext* donor_ir_context, const opt::BasicBlock& loop_header,
|
|
const std::map<uint32_t, uint32_t>& original_id_to_donated_id,
|
|
protobufs::LoopLimiterInfo* out) {
|
|
assert(loop_header.IsLoopHeader() && "|loop_header| is not a loop header");
|
|
|
|
// Grab the loop header's id, mapped to its donated value.
|
|
out->set_loop_header_id(original_id_to_donated_id.at(loop_header.id()));
|
|
|
|
// Get fresh ids that will be used to load the loop limiter, increment
|
|
// it, compare it with the loop limit, and an id for a new block that
|
|
// will contain the loop's original terminator.
|
|
out->set_load_id(GetFuzzerContext()->GetFreshId());
|
|
out->set_increment_id(GetFuzzerContext()->GetFreshId());
|
|
out->set_compare_id(GetFuzzerContext()->GetFreshId());
|
|
out->set_logical_op_id(GetFuzzerContext()->GetFreshId());
|
|
|
|
// We are creating a branch from the back-edge block to the merge block. Thus,
|
|
// if merge block has any OpPhi instructions, we might need to adjust
|
|
// them.
|
|
|
|
// Note that the loop might have an unreachable back-edge block. This means
|
|
// that the loop can't iterate, so we don't need to adjust anything.
|
|
const auto back_edge_block_id = TransformationAddFunction::GetBackEdgeBlockId(
|
|
donor_ir_context, loop_header.id());
|
|
if (!back_edge_block_id) {
|
|
return true;
|
|
}
|
|
|
|
auto* back_edge_block = donor_ir_context->cfg()->block(back_edge_block_id);
|
|
assert(back_edge_block && "|back_edge_block_id| is invalid");
|
|
|
|
const auto* merge_block =
|
|
donor_ir_context->cfg()->block(loop_header.MergeBlockId());
|
|
assert(merge_block && "Loop header has invalid merge block id");
|
|
|
|
// We don't need to adjust anything if there is already a branch from
|
|
// the back-edge block to the merge block.
|
|
if (back_edge_block->IsSuccessor(merge_block)) {
|
|
return true;
|
|
}
|
|
|
|
// Adjust OpPhi instructions in the |merge_block|.
|
|
for (const auto& inst : *merge_block) {
|
|
if (inst.opcode() != SpvOpPhi) {
|
|
break;
|
|
}
|
|
|
|
// There is no simple way to ensure that a chosen operand for the OpPhi
|
|
// instruction will never cause any problems (e.g. if we choose an
|
|
// integer id, it might have a zero value when we branch from the back
|
|
// edge block. This might cause a division by 0 later in the function.).
|
|
// Thus, we ignore possible problems and proceed as follows:
|
|
// - if any of the existing OpPhi operands dominates the back-edge
|
|
// block - use it
|
|
// - if OpPhi has a basic type (see IsBasicType method) - create
|
|
// a zero constant
|
|
// - otherwise, we can't add a livesafe function.
|
|
uint32_t suitable_operand_id = 0;
|
|
for (uint32_t i = 0; i < inst.NumInOperands(); i += 2) {
|
|
auto dependency_inst_id = inst.GetSingleWordInOperand(i);
|
|
|
|
if (fuzzerutil::IdIsAvailableBeforeInstruction(
|
|
donor_ir_context, back_edge_block->terminator(),
|
|
dependency_inst_id)) {
|
|
suitable_operand_id = original_id_to_donated_id.at(dependency_inst_id);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (suitable_operand_id == 0 &&
|
|
IsBasicType(
|
|
*donor_ir_context->get_def_use_mgr()->GetDef(inst.type_id()))) {
|
|
// We mark this constant as irrelevant so that we can replace it
|
|
// with more interesting value later.
|
|
suitable_operand_id = FindOrCreateZeroConstant(
|
|
original_id_to_donated_id.at(inst.type_id()), true);
|
|
}
|
|
|
|
if (suitable_operand_id == 0) {
|
|
return false;
|
|
}
|
|
|
|
out->add_phi_id(suitable_operand_id);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FuzzerPassDonateModules::MaybeAddLivesafeFunction(
|
|
const opt::Function& function_to_donate, opt::IRContext* donor_ir_context,
|
|
const std::map<uint32_t, uint32_t>& original_id_to_donated_id,
|
|
const std::vector<protobufs::Instruction>& donated_instructions) {
|
|
// Various types and constants must be in place for a function to be made
|
|
// live-safe. Add them if not already present.
|
|
FindOrCreateBoolType(); // Needed for comparisons
|
|
FindOrCreatePointerToIntegerType(
|
|
32, false, SpvStorageClassFunction); // Needed for adding loop limiters
|
|
FindOrCreateIntegerConstant({0}, 32, false,
|
|
false); // Needed for initializing loop limiters
|
|
FindOrCreateIntegerConstant({1}, 32, false,
|
|
false); // Needed for incrementing loop limiters
|
|
|
|
// Get a fresh id for the variable that will be used as a loop limiter.
|
|
const uint32_t loop_limiter_variable_id = GetFuzzerContext()->GetFreshId();
|
|
// Choose a random loop limit, and add the required constant to the
|
|
// module if not already there.
|
|
const uint32_t loop_limit = FindOrCreateIntegerConstant(
|
|
{GetFuzzerContext()->GetRandomLoopLimit()}, 32, false, false);
|
|
|
|
// Consider every loop header in the function to donate, and create a
|
|
// structure capturing the ids to be used for manipulating the loop
|
|
// limiter each time the loop is iterated.
|
|
std::vector<protobufs::LoopLimiterInfo> loop_limiters;
|
|
for (auto& block : function_to_donate) {
|
|
if (block.IsLoopHeader()) {
|
|
protobufs::LoopLimiterInfo loop_limiter;
|
|
|
|
if (!CreateLoopLimiterInfo(donor_ir_context, block,
|
|
original_id_to_donated_id, &loop_limiter)) {
|
|
return false;
|
|
}
|
|
|
|
loop_limiters.emplace_back(std::move(loop_limiter));
|
|
}
|
|
}
|
|
|
|
// Consider every access chain in the function to donate, and create a
|
|
// structure containing the ids necessary to clamp the access chain
|
|
// indices to be in-bounds.
|
|
std::vector<protobufs::AccessChainClampingInfo> access_chain_clamping_info;
|
|
for (auto& block : function_to_donate) {
|
|
for (auto& inst : block) {
|
|
switch (inst.opcode()) {
|
|
case SpvOpAccessChain:
|
|
case SpvOpInBoundsAccessChain: {
|
|
protobufs::AccessChainClampingInfo clamping_info;
|
|
clamping_info.set_access_chain_id(
|
|
original_id_to_donated_id.at(inst.result_id()));
|
|
|
|
auto base_object = donor_ir_context->get_def_use_mgr()->GetDef(
|
|
inst.GetSingleWordInOperand(0));
|
|
assert(base_object && "The base object must exist.");
|
|
auto pointer_type = donor_ir_context->get_def_use_mgr()->GetDef(
|
|
base_object->type_id());
|
|
assert(pointer_type && pointer_type->opcode() == SpvOpTypePointer &&
|
|
"The base object must have pointer type.");
|
|
|
|
auto should_be_composite_type =
|
|
donor_ir_context->get_def_use_mgr()->GetDef(
|
|
pointer_type->GetSingleWordInOperand(1));
|
|
|
|
// Walk the access chain, creating fresh ids to facilitate
|
|
// clamping each index. For simplicity we do this for every
|
|
// index, even though constant indices will not end up being
|
|
// clamped.
|
|
for (uint32_t index = 1; index < inst.NumInOperands(); index++) {
|
|
auto compare_and_select_ids =
|
|
clamping_info.add_compare_and_select_ids();
|
|
compare_and_select_ids->set_first(GetFuzzerContext()->GetFreshId());
|
|
compare_and_select_ids->set_second(
|
|
GetFuzzerContext()->GetFreshId());
|
|
|
|
// Get the bound for the component being indexed into.
|
|
uint32_t bound;
|
|
if (should_be_composite_type->opcode() == SpvOpTypeRuntimeArray) {
|
|
// The donor is indexing into a runtime array. We do not
|
|
// donate runtime arrays. Instead, we donate a corresponding
|
|
// fixed-size array for every runtime array. We should thus
|
|
// find that donor composite type's result id maps to a fixed-
|
|
// size array.
|
|
auto fixed_size_array_type =
|
|
GetIRContext()->get_def_use_mgr()->GetDef(
|
|
original_id_to_donated_id.at(
|
|
should_be_composite_type->result_id()));
|
|
assert(fixed_size_array_type->opcode() == SpvOpTypeArray &&
|
|
"A runtime array type in the donor should have been "
|
|
"replaced by a fixed-sized array in the recipient.");
|
|
// The size of this fixed-size array is a suitable bound.
|
|
bound = fuzzerutil::GetBoundForCompositeIndex(
|
|
*fixed_size_array_type, GetIRContext());
|
|
} else {
|
|
bound = fuzzerutil::GetBoundForCompositeIndex(
|
|
*should_be_composite_type, donor_ir_context);
|
|
}
|
|
const uint32_t index_id = inst.GetSingleWordInOperand(index);
|
|
auto index_inst =
|
|
donor_ir_context->get_def_use_mgr()->GetDef(index_id);
|
|
auto index_type_inst = donor_ir_context->get_def_use_mgr()->GetDef(
|
|
index_inst->type_id());
|
|
assert(index_type_inst->opcode() == SpvOpTypeInt);
|
|
opt::analysis::Integer* index_int_type =
|
|
donor_ir_context->get_type_mgr()
|
|
->GetType(index_type_inst->result_id())
|
|
->AsInteger();
|
|
if (index_inst->opcode() != SpvOpConstant) {
|
|
// We will have to clamp this index, so we need a constant
|
|
// whose value is one less than the bound, to compare
|
|
// against and to use as the clamped value.
|
|
FindOrCreateIntegerConstant({bound - 1}, 32,
|
|
index_int_type->IsSigned(), false);
|
|
}
|
|
should_be_composite_type =
|
|
TransformationAddFunction::FollowCompositeIndex(
|
|
donor_ir_context, *should_be_composite_type, index_id);
|
|
}
|
|
access_chain_clamping_info.push_back(clamping_info);
|
|
break;
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// If |function_to_donate| has non-void return type and contains an
|
|
// OpKill/OpUnreachable instruction, then a value is needed in order to turn
|
|
// these into instructions of the form OpReturnValue %value_id.
|
|
uint32_t kill_unreachable_return_value_id = 0;
|
|
auto function_return_type_inst =
|
|
donor_ir_context->get_def_use_mgr()->GetDef(function_to_donate.type_id());
|
|
if (function_return_type_inst->opcode() != SpvOpTypeVoid &&
|
|
fuzzerutil::FunctionContainsOpKillOrUnreachable(function_to_donate)) {
|
|
kill_unreachable_return_value_id = FindOrCreateZeroConstant(
|
|
original_id_to_donated_id.at(function_return_type_inst->result_id()),
|
|
false);
|
|
}
|
|
|
|
// Try to add the function in a livesafe manner. This may fail due to edge
|
|
// cases, e.g. where adding loop limiters changes dominance such that the
|
|
// module becomes invalid. It would be ideal to handle all such edge cases,
|
|
// but as they are rare it is more pragmatic to bail out of making the
|
|
// function livesafe if the transformation's precondition fails to hold.
|
|
return MaybeApplyTransformation(TransformationAddFunction(
|
|
donated_instructions, loop_limiter_variable_id, loop_limit, loop_limiters,
|
|
kill_unreachable_return_value_id, access_chain_clamping_info));
|
|
}
|
|
|
|
} // namespace fuzz
|
|
} // namespace spvtools
|