SPIRV-Tools/source/fuzz/transformation_composite_construct.cpp
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

287 lines
11 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_composite_construct.h"
#include "source/fuzz/data_descriptor.h"
#include "source/fuzz/fuzzer_util.h"
#include "source/fuzz/instruction_descriptor.h"
#include "source/opt/instruction.h"
namespace spvtools {
namespace fuzz {
TransformationCompositeConstruct::TransformationCompositeConstruct(
const protobufs::TransformationCompositeConstruct& message)
: message_(message) {}
TransformationCompositeConstruct::TransformationCompositeConstruct(
uint32_t composite_type_id, std::vector<uint32_t> component,
const protobufs::InstructionDescriptor& instruction_to_insert_before,
uint32_t fresh_id) {
message_.set_composite_type_id(composite_type_id);
for (auto a_component : component) {
message_.add_component(a_component);
}
*message_.mutable_instruction_to_insert_before() =
instruction_to_insert_before;
message_.set_fresh_id(fresh_id);
}
bool TransformationCompositeConstruct::IsApplicable(
opt::IRContext* context, const FactManager& /*fact_manager*/) const {
if (!fuzzerutil::IsFreshId(context, message_.fresh_id())) {
// We require the id for the composite constructor to be unused.
return false;
}
auto insert_before =
FindInstruction(message_.instruction_to_insert_before(), context);
if (!insert_before) {
// The instruction before which the composite should be inserted was not
// found.
return false;
}
auto composite_type =
context->get_type_mgr()->GetType(message_.composite_type_id());
if (!fuzzerutil::IsCompositeType(composite_type)) {
// The type must actually be a composite.
return false;
}
// If the type is an array, matrix, struct or vector, the components need to
// be suitable for constructing something of that type.
if (composite_type->AsArray() && !ComponentsForArrayConstructionAreOK(
context, *composite_type->AsArray())) {
return false;
}
if (composite_type->AsMatrix() && !ComponentsForMatrixConstructionAreOK(
context, *composite_type->AsMatrix())) {
return false;
}
if (composite_type->AsStruct() && !ComponentsForStructConstructionAreOK(
context, *composite_type->AsStruct())) {
return false;
}
if (composite_type->AsVector() && !ComponentsForVectorConstructionAreOK(
context, *composite_type->AsVector())) {
return false;
}
// Now check whether every component being used to initialize the composite is
// available at the desired program point.
for (auto& component : message_.component()) {
if (!fuzzerutil::IdIsAvailableBeforeInstruction(context, insert_before,
component)) {
return false;
}
}
return true;
}
void TransformationCompositeConstruct::Apply(opt::IRContext* context,
FactManager* fact_manager) const {
// Use the base and offset information from the transformation to determine
// where in the module a new instruction should be inserted.
auto insert_before_inst =
FindInstruction(message_.instruction_to_insert_before(), context);
auto destination_block = context->get_instr_block(insert_before_inst);
auto insert_before = fuzzerutil::GetIteratorForInstruction(
destination_block, insert_before_inst);
// Prepare the input operands for an OpCompositeConstruct instruction.
opt::Instruction::OperandList in_operands;
for (auto& component_id : message_.component()) {
in_operands.push_back({SPV_OPERAND_TYPE_ID, {component_id}});
}
// Insert an OpCompositeConstruct instruction.
insert_before.InsertBefore(MakeUnique<opt::Instruction>(
context, SpvOpCompositeConstruct, message_.composite_type_id(),
message_.fresh_id(), in_operands));
fuzzerutil::UpdateModuleIdBound(context, message_.fresh_id());
context->InvalidateAnalysesExceptFor(opt::IRContext::kAnalysisNone);
// Inform the fact manager that we now have new synonyms: every component of
// the composite is synonymous with the id used to construct that component,
// except in the case of a vector where a single vector id can span multiple
// components.
auto composite_type =
context->get_type_mgr()->GetType(message_.composite_type_id());
uint32_t index = 0;
for (auto component : message_.component()) {
auto component_type = context->get_type_mgr()->GetType(
context->get_def_use_mgr()->GetDef(component)->type_id());
if (composite_type->AsVector() && component_type->AsVector()) {
// The case where the composite being constructed is a vector and the
// component provided for construction is also a vector is special. It
// requires adding a synonym fact relating each element of the sub-vector
// to the corresponding element of the composite being constructed.
assert(component_type->AsVector()->element_type() ==
composite_type->AsVector()->element_type());
assert(component_type->AsVector()->element_count() <
composite_type->AsVector()->element_count());
for (uint32_t subvector_index = 0;
subvector_index < component_type->AsVector()->element_count();
subvector_index++) {
fact_manager->AddFactDataSynonym(
MakeDataDescriptor(component, {subvector_index}),
MakeDataDescriptor(message_.fresh_id(), {index}), context);
index++;
}
} else {
// The other cases are simple: the component is made directly synonymous
// with the element of the composite being constructed.
fact_manager->AddFactDataSynonym(
MakeDataDescriptor(component, {}),
MakeDataDescriptor(message_.fresh_id(), {index}), context);
index++;
}
}
}
bool TransformationCompositeConstruct::ComponentsForArrayConstructionAreOK(
opt::IRContext* context, const opt::analysis::Array& array_type) const {
if (array_type.length_info().words[0] !=
opt::analysis::Array::LengthInfo::kConstant) {
// We only handle constant-sized arrays.
return false;
}
if (array_type.length_info().words.size() != 2) {
// We only handle the case where the array size can be captured in a single
// word.
return false;
}
// Get the array size.
auto array_size = array_type.length_info().words[1];
if (static_cast<uint32_t>(message_.component().size()) != array_size) {
// The number of components must match the array size.
return false;
}
// Check that each component is the result id of an instruction whose type is
// the array's element type.
for (auto component_id : message_.component()) {
auto inst = context->get_def_use_mgr()->GetDef(component_id);
if (inst == nullptr || !inst->type_id()) {
// The component does not correspond to an instruction with a result
// type.
return false;
}
auto component_type = context->get_type_mgr()->GetType(inst->type_id());
assert(component_type);
if (component_type != array_type.element_type()) {
// The component's type does not match the array's element type.
return false;
}
}
return true;
}
bool TransformationCompositeConstruct::ComponentsForMatrixConstructionAreOK(
opt::IRContext* context, const opt::analysis::Matrix& matrix_type) const {
if (static_cast<uint32_t>(message_.component().size()) !=
matrix_type.element_count()) {
// The number of components must match the number of columns of the matrix.
return false;
}
// Check that each component is the result id of an instruction whose type is
// the matrix's column type.
for (auto component_id : message_.component()) {
auto inst = context->get_def_use_mgr()->GetDef(component_id);
if (inst == nullptr || !inst->type_id()) {
// The component does not correspond to an instruction with a result
// type.
return false;
}
auto component_type = context->get_type_mgr()->GetType(inst->type_id());
assert(component_type);
if (component_type != matrix_type.element_type()) {
// The component's type does not match the matrix's column type.
return false;
}
}
return true;
}
bool TransformationCompositeConstruct::ComponentsForStructConstructionAreOK(
opt::IRContext* context, const opt::analysis::Struct& struct_type) const {
if (static_cast<uint32_t>(message_.component().size()) !=
struct_type.element_types().size()) {
// The number of components must match the number of fields of the struct.
return false;
}
// Check that each component is the result id of an instruction those type
// matches the associated field type.
for (uint32_t field_index = 0;
field_index < struct_type.element_types().size(); field_index++) {
auto inst =
context->get_def_use_mgr()->GetDef(message_.component()[field_index]);
if (inst == nullptr || !inst->type_id()) {
// The component does not correspond to an instruction with a result
// type.
return false;
}
auto component_type = context->get_type_mgr()->GetType(inst->type_id());
assert(component_type);
if (component_type != struct_type.element_types()[field_index]) {
// The component's type does not match the corresponding field type.
return false;
}
}
return true;
}
bool TransformationCompositeConstruct::ComponentsForVectorConstructionAreOK(
opt::IRContext* context, const opt::analysis::Vector& vector_type) const {
uint32_t base_element_count = 0;
auto element_type = vector_type.element_type();
for (auto& component_id : message_.component()) {
auto inst = context->get_def_use_mgr()->GetDef(component_id);
if (inst == nullptr || !inst->type_id()) {
// The component does not correspond to an instruction with a result
// type.
return false;
}
auto component_type = context->get_type_mgr()->GetType(inst->type_id());
assert(component_type);
if (component_type == element_type) {
base_element_count++;
} else if (component_type->AsVector() &&
component_type->AsVector()->element_type() == element_type) {
base_element_count += component_type->AsVector()->element_count();
} else {
// The component was not appropriate; e.g. no type corresponding to the
// given id was found, or the type that was found was not compatible
// with the vector being constructed.
return false;
}
}
// The number of components provided (when vector components are flattened
// out) needs to match the length of the vector being constructed.
return base_element_count == vector_type.element_count();
}
protobufs::Transformation TransformationCompositeConstruct::ToMessage() const {
protobufs::Transformation result;
*result.mutable_composite_construct() = message_;
return result;
}
} // namespace fuzz
} // namespace spvtools