SPIRV-Tools/source/fuzz/fuzzer_util.cpp
Alastair Donaldson f82d47003e
spirv-fuzz: Respect rules for OpSampledImage (#3287)
The SPIR-V data rules say that all uses of an OpSampledImage
instruction must be in the same block as the instruction, and highly
restrict those instructions that can consume the result id of an
OpSampledImage.

This adapts the transformations that split blocks and create synonyms
to avoid separating an OpSampledImage use from its definition, and to
avoid synonym-creation instructions such as OpCopyObject consuming an
OpSampledImage result id.
2020-04-14 20:17:42 +01:00

557 lines
20 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/fuzzer_util.h"
#include "source/opt/build_module.h"
namespace spvtools {
namespace fuzz {
namespace fuzzerutil {
bool IsFreshId(opt::IRContext* context, uint32_t id) {
return !context->get_def_use_mgr()->GetDef(id);
}
void UpdateModuleIdBound(opt::IRContext* context, uint32_t id) {
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/2541) consider the
// case where the maximum id bound is reached.
context->module()->SetIdBound(
std::max(context->module()->id_bound(), id + 1));
}
opt::BasicBlock* MaybeFindBlock(opt::IRContext* context,
uint32_t maybe_block_id) {
auto inst = context->get_def_use_mgr()->GetDef(maybe_block_id);
if (inst == nullptr) {
// No instruction defining this id was found.
return nullptr;
}
if (inst->opcode() != SpvOpLabel) {
// The instruction defining the id is not a label, so it cannot be a block
// id.
return nullptr;
}
return context->cfg()->block(maybe_block_id);
}
bool PhiIdsOkForNewEdge(
opt::IRContext* context, opt::BasicBlock* bb_from, opt::BasicBlock* bb_to,
const google::protobuf::RepeatedField<google::protobuf::uint32>& phi_ids) {
if (bb_from->IsSuccessor(bb_to)) {
// There is already an edge from |from_block| to |to_block|, so there is
// no need to extend OpPhi instructions. Do not allow phi ids to be
// present. This might turn out to be too strict; perhaps it would be OK
// just to ignore the ids in this case.
return phi_ids.empty();
}
// The edge would add a previously non-existent edge from |from_block| to
// |to_block|, so we go through the given phi ids and check that they exactly
// match the OpPhi instructions in |to_block|.
uint32_t phi_index = 0;
// An explicit loop, rather than applying a lambda to each OpPhi in |bb_to|,
// makes sense here because we need to increment |phi_index| for each OpPhi
// instruction.
for (auto& inst : *bb_to) {
if (inst.opcode() != SpvOpPhi) {
// The OpPhi instructions all occur at the start of the block; if we find
// a non-OpPhi then we have seen them all.
break;
}
if (phi_index == static_cast<uint32_t>(phi_ids.size())) {
// Not enough phi ids have been provided to account for the OpPhi
// instructions.
return false;
}
// Look for an instruction defining the next phi id.
opt::Instruction* phi_extension =
context->get_def_use_mgr()->GetDef(phi_ids[phi_index]);
if (!phi_extension) {
// The id given to extend this OpPhi does not exist.
return false;
}
if (phi_extension->type_id() != inst.type_id()) {
// The instruction given to extend this OpPhi either does not have a type
// or its type does not match that of the OpPhi.
return false;
}
if (context->get_instr_block(phi_extension)) {
// The instruction defining the phi id has an associated block (i.e., it
// is not a global value). Check whether its definition dominates the
// exit of |from_block|.
auto dominator_analysis =
context->GetDominatorAnalysis(bb_from->GetParent());
if (!dominator_analysis->Dominates(phi_extension,
bb_from->terminator())) {
// The given id is no good as its definition does not dominate the exit
// of |from_block|
return false;
}
}
phi_index++;
}
// We allow some of the ids provided for extending OpPhi instructions to be
// unused. Their presence does no harm, and requiring a perfect match may
// make transformations less likely to cleanly apply.
return true;
}
uint32_t MaybeGetBoolConstantId(opt::IRContext* context, bool value) {
opt::analysis::Bool bool_type;
auto registered_bool_type =
context->get_type_mgr()->GetRegisteredType(&bool_type);
if (!registered_bool_type) {
return 0;
}
opt::analysis::BoolConstant bool_constant(registered_bool_type->AsBool(),
value);
return context->get_constant_mgr()->FindDeclaredConstant(
&bool_constant, context->get_type_mgr()->GetId(&bool_type));
}
void AddUnreachableEdgeAndUpdateOpPhis(
opt::IRContext* context, opt::BasicBlock* bb_from, opt::BasicBlock* bb_to,
bool condition_value,
const google::protobuf::RepeatedField<google::protobuf::uint32>& phi_ids) {
assert(PhiIdsOkForNewEdge(context, bb_from, bb_to, phi_ids) &&
"Precondition on phi_ids is not satisfied");
assert(bb_from->terminator()->opcode() == SpvOpBranch &&
"Precondition on terminator of bb_from is not satisfied");
// Get the id of the boolean constant to be used as the condition.
uint32_t bool_id = MaybeGetBoolConstantId(context, condition_value);
assert(
bool_id &&
"Precondition that condition value must be available is not satisfied");
const bool from_to_edge_already_exists = bb_from->IsSuccessor(bb_to);
auto successor = bb_from->terminator()->GetSingleWordInOperand(0);
// Add the dead branch, by turning OpBranch into OpBranchConditional, and
// ordering the targets depending on whether the given boolean corresponds to
// true or false.
bb_from->terminator()->SetOpcode(SpvOpBranchConditional);
bb_from->terminator()->SetInOperands(
{{SPV_OPERAND_TYPE_ID, {bool_id}},
{SPV_OPERAND_TYPE_ID, {condition_value ? successor : bb_to->id()}},
{SPV_OPERAND_TYPE_ID, {condition_value ? bb_to->id() : successor}}});
// Update OpPhi instructions in the target block if this branch adds a
// previously non-existent edge from source to target.
if (!from_to_edge_already_exists) {
uint32_t phi_index = 0;
for (auto& inst : *bb_to) {
if (inst.opcode() != SpvOpPhi) {
break;
}
assert(phi_index < static_cast<uint32_t>(phi_ids.size()) &&
"There should be at least one phi id per OpPhi instruction.");
inst.AddOperand({SPV_OPERAND_TYPE_ID, {phi_ids[phi_index]}});
inst.AddOperand({SPV_OPERAND_TYPE_ID, {bb_from->id()}});
phi_index++;
}
}
}
bool BlockIsInLoopContinueConstruct(opt::IRContext* context, uint32_t block_id,
uint32_t maybe_loop_header_id) {
// We deem a block to be part of a loop's continue construct if the loop's
// continue target dominates the block.
auto containing_construct_block = context->cfg()->block(maybe_loop_header_id);
if (containing_construct_block->IsLoopHeader()) {
auto continue_target = containing_construct_block->ContinueBlockId();
if (context->GetDominatorAnalysis(containing_construct_block->GetParent())
->Dominates(continue_target, block_id)) {
return true;
}
}
return false;
}
opt::BasicBlock::iterator GetIteratorForInstruction(
opt::BasicBlock* block, const opt::Instruction* inst) {
for (auto inst_it = block->begin(); inst_it != block->end(); ++inst_it) {
if (inst == &*inst_it) {
return inst_it;
}
}
return block->end();
}
bool BlockIsReachableInItsFunction(opt::IRContext* context,
opt::BasicBlock* bb) {
auto enclosing_function = bb->GetParent();
return context->GetDominatorAnalysis(enclosing_function)
->Dominates(enclosing_function->entry().get(), bb);
}
bool CanInsertOpcodeBeforeInstruction(
SpvOp opcode, const opt::BasicBlock::iterator& instruction_in_block) {
if (instruction_in_block->PreviousNode() &&
(instruction_in_block->PreviousNode()->opcode() == SpvOpLoopMerge ||
instruction_in_block->PreviousNode()->opcode() == SpvOpSelectionMerge)) {
// We cannot insert directly after a merge instruction.
return false;
}
if (opcode != SpvOpVariable &&
instruction_in_block->opcode() == SpvOpVariable) {
// We cannot insert a non-OpVariable instruction directly before a
// variable; variables in a function must be contiguous in the entry block.
return false;
}
// We cannot insert a non-OpPhi instruction directly before an OpPhi, because
// OpPhi instructions need to be contiguous at the start of a block.
return opcode == SpvOpPhi || instruction_in_block->opcode() != SpvOpPhi;
}
bool CanMakeSynonymOf(opt::IRContext* ir_context, opt::Instruction* inst) {
if (inst->opcode() == SpvOpSampledImage) {
// The SPIR-V data rules say that only very specific instructions may
// may consume the result id of an OpSampledImage, and this excludes the
// instructions that are used for making synonyms.
return false;
}
if (!inst->HasResultId()) {
// We can only make a synonym of an instruction that generates an id.
return false;
}
if (!inst->type_id()) {
// We can only make a synonym of an instruction that has a type.
return false;
}
auto type_inst = ir_context->get_def_use_mgr()->GetDef(inst->type_id());
if (type_inst->opcode() == SpvOpTypePointer) {
switch (inst->opcode()) {
case SpvOpConstantNull:
case SpvOpUndef:
// We disallow making synonyms of null or undefined pointers. This is
// to provide the property that if the original shader exhibited no bad
// pointer accesses, the transformed shader will not either.
return false;
default:
break;
}
}
// We do not make synonyms of objects that have decorations: if the synonym is
// not decorated analogously, using the original object vs. its synonymous
// form may not be equivalent.
return ir_context->get_decoration_mgr()
->GetDecorationsFor(inst->result_id(), true)
.empty();
}
bool IsCompositeType(const opt::analysis::Type* type) {
return type && (type->AsArray() || type->AsMatrix() || type->AsStruct() ||
type->AsVector());
}
std::vector<uint32_t> RepeatedFieldToVector(
const google::protobuf::RepeatedField<uint32_t>& repeated_field) {
std::vector<uint32_t> result;
for (auto i : repeated_field) {
result.push_back(i);
}
return result;
}
uint32_t WalkOneCompositeTypeIndex(opt::IRContext* context,
uint32_t base_object_type_id,
uint32_t index) {
auto should_be_composite_type =
context->get_def_use_mgr()->GetDef(base_object_type_id);
assert(should_be_composite_type && "The type should exist.");
switch (should_be_composite_type->opcode()) {
case SpvOpTypeArray: {
auto array_length = GetArraySize(*should_be_composite_type, context);
if (array_length == 0 || index >= array_length) {
return 0;
}
return should_be_composite_type->GetSingleWordInOperand(0);
}
case SpvOpTypeMatrix:
case SpvOpTypeVector: {
auto count = should_be_composite_type->GetSingleWordInOperand(1);
if (index >= count) {
return 0;
}
return should_be_composite_type->GetSingleWordInOperand(0);
}
case SpvOpTypeStruct: {
if (index >= GetNumberOfStructMembers(*should_be_composite_type)) {
return 0;
}
return should_be_composite_type->GetSingleWordInOperand(index);
}
default:
return 0;
}
}
uint32_t WalkCompositeTypeIndices(
opt::IRContext* context, uint32_t base_object_type_id,
const google::protobuf::RepeatedField<google::protobuf::uint32>& indices) {
uint32_t sub_object_type_id = base_object_type_id;
for (auto index : indices) {
sub_object_type_id =
WalkOneCompositeTypeIndex(context, sub_object_type_id, index);
if (!sub_object_type_id) {
return 0;
}
}
return sub_object_type_id;
}
uint32_t GetNumberOfStructMembers(
const opt::Instruction& struct_type_instruction) {
assert(struct_type_instruction.opcode() == SpvOpTypeStruct &&
"An OpTypeStruct instruction is required here.");
return struct_type_instruction.NumInOperands();
}
uint32_t GetArraySize(const opt::Instruction& array_type_instruction,
opt::IRContext* context) {
auto array_length_constant =
context->get_constant_mgr()
->GetConstantFromInst(context->get_def_use_mgr()->GetDef(
array_type_instruction.GetSingleWordInOperand(1)))
->AsIntConstant();
if (array_length_constant->words().size() != 1) {
return 0;
}
return array_length_constant->GetU32();
}
bool IsValid(opt::IRContext* context, spv_validator_options validator_options) {
std::vector<uint32_t> binary;
context->module()->ToBinary(&binary, false);
SpirvTools tools(context->grammar().target_env());
return tools.Validate(binary.data(), binary.size(), validator_options);
}
std::unique_ptr<opt::IRContext> CloneIRContext(opt::IRContext* context) {
std::vector<uint32_t> binary;
context->module()->ToBinary(&binary, false);
return BuildModule(context->grammar().target_env(), nullptr, binary.data(),
binary.size());
}
bool IsNonFunctionTypeId(opt::IRContext* ir_context, uint32_t id) {
auto type = ir_context->get_type_mgr()->GetType(id);
return type && !type->AsFunction();
}
bool IsMergeOrContinue(opt::IRContext* ir_context, uint32_t block_id) {
bool result = false;
ir_context->get_def_use_mgr()->WhileEachUse(
block_id,
[&result](const opt::Instruction* use_instruction,
uint32_t /*unused*/) -> bool {
switch (use_instruction->opcode()) {
case SpvOpLoopMerge:
case SpvOpSelectionMerge:
result = true;
return false;
default:
return true;
}
});
return result;
}
uint32_t FindFunctionType(opt::IRContext* ir_context,
const std::vector<uint32_t>& type_ids) {
// Look through the existing types for a match.
for (auto& type_or_value : ir_context->types_values()) {
if (type_or_value.opcode() != SpvOpTypeFunction) {
// We are only interested in function types.
continue;
}
if (type_or_value.NumInOperands() != type_ids.size()) {
// Not a match: different numbers of arguments.
continue;
}
// Check whether the return type and argument types match.
bool input_operands_match = true;
for (uint32_t i = 0; i < type_or_value.NumInOperands(); i++) {
if (type_ids[i] != type_or_value.GetSingleWordInOperand(i)) {
input_operands_match = false;
break;
}
}
if (input_operands_match) {
// Everything matches.
return type_or_value.result_id();
}
}
// No match was found.
return 0;
}
opt::Instruction* GetFunctionType(opt::IRContext* context,
const opt::Function* function) {
uint32_t type_id = function->DefInst().GetSingleWordInOperand(1);
return context->get_def_use_mgr()->GetDef(type_id);
}
opt::Function* FindFunction(opt::IRContext* ir_context, uint32_t function_id) {
for (auto& function : *ir_context->module()) {
if (function.result_id() == function_id) {
return &function;
}
}
return nullptr;
}
bool FunctionIsEntryPoint(opt::IRContext* context, uint32_t function_id) {
for (auto& entry_point : context->module()->entry_points()) {
if (entry_point.GetSingleWordInOperand(1) == function_id) {
return true;
}
}
return false;
}
bool IdIsAvailableAtUse(opt::IRContext* context,
opt::Instruction* use_instruction,
uint32_t use_input_operand_index, uint32_t id) {
auto defining_instruction = context->get_def_use_mgr()->GetDef(id);
auto enclosing_function =
context->get_instr_block(use_instruction)->GetParent();
// If the id a function parameter, it needs to be associated with the
// function containing the use.
if (defining_instruction->opcode() == SpvOpFunctionParameter) {
return InstructionIsFunctionParameter(defining_instruction,
enclosing_function);
}
if (!context->get_instr_block(id)) {
// The id must be at global scope.
return true;
}
if (defining_instruction == use_instruction) {
// It is not OK for a definition to use itself.
return false;
}
auto dominator_analysis = context->GetDominatorAnalysis(enclosing_function);
if (use_instruction->opcode() == SpvOpPhi) {
// In the case where the use is an operand to OpPhi, it is actually the
// *parent* block associated with the operand that must be dominated by
// the synonym.
auto parent_block =
use_instruction->GetSingleWordInOperand(use_input_operand_index + 1);
return dominator_analysis->Dominates(
context->get_instr_block(defining_instruction)->id(), parent_block);
}
return dominator_analysis->Dominates(defining_instruction, use_instruction);
}
bool IdIsAvailableBeforeInstruction(opt::IRContext* context,
opt::Instruction* instruction,
uint32_t id) {
auto defining_instruction = context->get_def_use_mgr()->GetDef(id);
auto enclosing_function = context->get_instr_block(instruction)->GetParent();
// If the id a function parameter, it needs to be associated with the
// function containing the instruction.
if (defining_instruction->opcode() == SpvOpFunctionParameter) {
return InstructionIsFunctionParameter(defining_instruction,
enclosing_function);
}
if (!context->get_instr_block(id)) {
// The id is at global scope.
return true;
}
if (defining_instruction == instruction) {
// The instruction is not available right before its own definition.
return false;
}
return context->GetDominatorAnalysis(enclosing_function)
->Dominates(defining_instruction, instruction);
}
bool InstructionIsFunctionParameter(opt::Instruction* instruction,
opt::Function* function) {
if (instruction->opcode() != SpvOpFunctionParameter) {
return false;
}
bool found_parameter = false;
function->ForEachParam(
[instruction, &found_parameter](opt::Instruction* param) {
if (param == instruction) {
found_parameter = true;
}
});
return found_parameter;
}
uint32_t GetTypeId(opt::IRContext* context, uint32_t result_id) {
return context->get_def_use_mgr()->GetDef(result_id)->type_id();
}
uint32_t GetPointeeTypeIdFromPointerType(opt::Instruction* pointer_type_inst) {
assert(pointer_type_inst && pointer_type_inst->opcode() == SpvOpTypePointer &&
"Precondition: |pointer_type_inst| must be OpTypePointer.");
return pointer_type_inst->GetSingleWordInOperand(1);
}
uint32_t GetPointeeTypeIdFromPointerType(opt::IRContext* context,
uint32_t pointer_type_id) {
return GetPointeeTypeIdFromPointerType(
context->get_def_use_mgr()->GetDef(pointer_type_id));
}
SpvStorageClass GetStorageClassFromPointerType(
opt::Instruction* pointer_type_inst) {
assert(pointer_type_inst && pointer_type_inst->opcode() == SpvOpTypePointer &&
"Precondition: |pointer_type_inst| must be OpTypePointer.");
return static_cast<SpvStorageClass>(
pointer_type_inst->GetSingleWordInOperand(0));
}
SpvStorageClass GetStorageClassFromPointerType(opt::IRContext* context,
uint32_t pointer_type_id) {
return GetStorageClassFromPointerType(
context->get_def_use_mgr()->GetDef(pointer_type_id));
}
uint32_t MaybeGetPointerType(opt::IRContext* context, uint32_t pointee_type_id,
SpvStorageClass storage_class) {
for (auto& inst : context->types_values()) {
switch (inst.opcode()) {
case SpvOpTypePointer:
if (inst.GetSingleWordInOperand(0) == storage_class &&
inst.GetSingleWordInOperand(1) == pointee_type_id) {
return inst.result_id();
}
break;
default:
break;
}
}
return 0;
}
bool IsNullConstantSupported(const opt::analysis::Type& type) {
return type.AsBool() || type.AsInteger() || type.AsFloat() ||
type.AsMatrix() || type.AsVector() || type.AsArray() ||
type.AsStruct() || type.AsPointer() || type.AsEvent() ||
type.AsDeviceEvent() || type.AsReserveId() || type.AsQueue();
}
} // namespace fuzzerutil
} // namespace fuzz
} // namespace spvtools