// Copyright (c) 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SOURCE_FUZZ_FUZZER_PASS_H_
#define SOURCE_FUZZ_FUZZER_PASS_H_
#include <functional>
#include <vector>
#include "source/fuzz/fuzzer_context.h"
#include "source/fuzz/protobufs/spirvfuzz_protobufs.h"
#include "source/fuzz/transformation.h"
#include "source/fuzz/transformation_context.h"
#include "source/opt/ir_context.h"
namespace spvtools {
namespace fuzz {
// Interface for applying a pass of transformations to a module.
class FuzzerPass {
public:
FuzzerPass(opt::IRContext* ir_context,
TransformationContext* transformation_context,
FuzzerContext* fuzzer_context,
protobufs::TransformationSequence* transformations);
virtual ~FuzzerPass();
// Applies the pass to the module |ir_context_|, assuming and updating
// information from |transformation_context_|, and using |fuzzer_context_| to
// guide the process. Appends to |transformations_| all transformations that
// were applied during the pass.
virtual void Apply() = 0;
protected:
opt::IRContext* GetIRContext() const { return ir_context_; }
TransformationContext* GetTransformationContext() const {
return transformation_context_;
}
FuzzerContext* GetFuzzerContext() const { return fuzzer_context_; }
protobufs::TransformationSequence* GetTransformations() const {
return transformations_;
}
// Returns all instructions that are *available* at |inst_it|, which is
// required to be inside block |block| of function |function| - that is, all
// instructions at global scope and all instructions that strictly dominate
// |inst_it|.
//
// Filters said instructions to return only those that satisfy the
// |instruction_is_relevant| predicate. This, for instance, could ignore all
// instructions that have a particular decoration.
std::vector<opt::Instruction*> FindAvailableInstructions(
opt::Function* function, opt::BasicBlock* block,
const opt::BasicBlock::iterator& inst_it,
std::function<bool(opt::IRContext*, opt::Instruction*)>
instruction_is_relevant) const;
// A helper method that iterates through each instruction in each reachable
// block of |function|, at all times tracking an instruction descriptor that
// allows the latest instruction to be located even if it has no result id.
//
// The code to manipulate the instruction descriptor is a bit fiddly. The
// point of this method is to avoiding having to duplicate it in multiple
// transformation passes.
//
// The function |action| is invoked for each instruction |inst_it| in block
// |block| of function |function| that is encountered. The
// |instruction_descriptor| parameter to the function object allows |inst_it|
// to be identified.
//
// In most intended use cases, the job of |action| is to randomly decide
// whether to try to apply some transformation, and then - if selected - to
// attempt to apply it.
void ForEachInstructionWithInstructionDescriptor(
opt::Function* function,
std::function<
void(opt::BasicBlock* block, opt::BasicBlock::iterator inst_it,
const protobufs::InstructionDescriptor& instruction_descriptor)>
action);
// Applies the above overload of ForEachInstructionWithInstructionDescriptor
// to every function in the module, so that |action| is applied to an
// |instruction_descriptor| for every instruction, |inst_it|, of every |block|
// in every |function|.
void ForEachInstructionWithInstructionDescriptor(
std::function<
void(opt::Function* function, opt::BasicBlock* block,
opt::BasicBlock::iterator inst_it,
const protobufs::InstructionDescriptor& instruction_descriptor)>
action);
// A generic helper for applying a transformation that should be applicable
// by construction, and adding it to the sequence of applied transformations.
void ApplyTransformation(const Transformation& transformation) {
assert(transformation.IsApplicable(GetIRContext(),
*GetTransformationContext()) &&
"Transformation should be applicable by construction.");
transformation.Apply(GetIRContext(), GetTransformationContext());
protobufs::Transformation transformation_message =
transformation.ToMessage();
assert(transformation_message.transformation_case() !=
protobufs::Transformation::TRANSFORMATION_NOT_SET &&
"Bad transformation.");
*GetTransformations()->add_transformation() = transformation_message;
}
// A generic helper for applying a transformation only if it is applicable.
// If it is applicable, the transformation is applied and then added to the
// sequence of applied transformations and the function returns true.
// Otherwise, the function returns false.
bool MaybeApplyTransformation(const Transformation& transformation) {
if (transformation.IsApplicable(GetIRContext(),
*GetTransformationContext())) {
transformation.Apply(GetIRContext(), GetTransformationContext());
protobufs::Transformation transformation_message =
transformation.ToMessage();
assert(transformation_message.transformation_case() !=
protobufs::Transformation::TRANSFORMATION_NOT_SET &&
"Bad transformation.");
*GetTransformations()->add_transformation() = transformation_message;
return true;
}
return false;
}
// Returns the id of an OpTypeBool instruction. If such an instruction does
// not exist, a transformation is applied to add it.
uint32_t FindOrCreateBoolType();
// Returns the id of an OpTypeInt instruction, with width and signedness
// specified by |width| and |is_signed|, respectively. If such an instruction
// does not exist, a transformation is applied to add it.
uint32_t FindOrCreateIntegerType(uint32_t width, bool is_signed);
// Returns the id of an OpTypeFloat instruction, with width specified by
// |width|. If such an instruction does not exist, a transformation is
// applied to add it.
uint32_t FindOrCreateFloatType(uint32_t width);
// Returns the id of an OpTypeFunction %<return_type_id> %<...argument_id>
// instruction. If such an instruction doesn't exist, a transformation
// is applied to create a new one.
uint32_t FindOrCreateFunctionType(uint32_t return_type_id,
const std::vector<uint32_t>& argument_id);
// Returns the id of an OpTypeVector instruction, with |component_type_id|
// (which must already exist) as its base type, and |component_count|
// elements (which must be in the range [2, 4]). If such an instruction does
// not exist, a transformation is applied to add it.
uint32_t FindOrCreateVectorType(uint32_t component_type_id,
uint32_t component_count);
// Returns the id of an OpTypeMatrix instruction, with |column_count| columns
// and |row_count| rows (each of which must be in the range [2, 4]). If the
// float and vector types required to build this matrix type or the matrix
// type itself do not exist, transformations are applied to add them.
uint32_t FindOrCreateMatrixType(uint32_t column_count, uint32_t row_count);
// Returns the id of an OpTypeStruct instruction with |component_type_ids| as
// type ids for struct's components. If no such a struct type exists,
// transformations are applied to add it. |component_type_ids| may not contain
// a result id of an OpTypeFunction.
uint32_t FindOrCreateStructType(
const std::vector<uint32_t>& component_type_ids);
// Returns the id of a pointer type with base type |base_type_id| (which must
// already exist) and storage class |storage_class|. A transformation is
// applied to add the pointer if it does not already exist.
uint32_t FindOrCreatePointerType(uint32_t base_type_id,
SpvStorageClass storage_class);
// Returns the id of an OpTypePointer instruction, with a integer base
// type of width and signedness specified by |width| and |is_signed|,
// respectively. If the pointer type or required integer base type do not
// exist, transformations are applied to add them.
uint32_t FindOrCreatePointerToIntegerType(uint32_t width, bool is_signed,
SpvStorageClass storage_class);
// Returns the id of an OpConstant instruction, with a integer type of
// width and signedness specified by |width| and |is_signed|, respectively,
// with |words| as its value. If either the required integer type or the
// constant do not exist, transformations are applied to add them.
// The returned id either participates in IdIsIrrelevant fact or not,
// depending on the |is_irrelevant| parameter.
uint32_t FindOrCreateIntegerConstant(const std::vector<uint32_t>& words,
uint32_t width, bool is_signed,
bool is_irrelevant);
// Returns the id of an OpConstant instruction, with a floating-point
// type of width specified by |width|, with |words| as its value. If either
// the required floating-point type or the constant do not exist,
// transformations are applied to add them. The returned id either
// participates in IdIsIrrelevant fact or not, depending on the
// |is_irrelevant| parameter.
uint32_t FindOrCreateFloatConstant(const std::vector<uint32_t>& words,
uint32_t width, bool is_irrelevant);
// Returns the id of an OpConstantTrue or OpConstantFalse instruction,
// according to |value|. If either the required instruction or the bool
// type do not exist, transformations are applied to add them.
// The returned id either participates in IdIsIrrelevant fact or not,
// depending on the |is_irrelevant| parameter.
uint32_t FindOrCreateBoolConstant(bool value, bool is_irrelevant);
// Returns the id of an OpConstant instruction of type with |type_id|
// that consists of |words|. If that instruction doesn't exist,
// transformations are applied to add it. |type_id| must be a valid
// result id of either scalar or boolean OpType* instruction that exists
// in the module. The returned id either participates in IdIsIrrelevant fact
// or not, depending on the |is_irrelevant| parameter.
uint32_t FindOrCreateConstant(const std::vector<uint32_t>& words,
uint32_t type_id, bool is_irrelevant);
// Returns the id of an OpConstantComposite instruction of type with |type_id|
// that consists of |component_ids|. If that instruction doesn't exist,
// transformations are applied to add it. |type_id| must be a valid
// result id of an OpType* instruction that represents a composite type
// (i.e. a vector, matrix, struct or array).
// The returned id either participates in IdIsIrrelevant fact or not,
// depending on the |is_irrelevant| parameter.
uint32_t FindOrCreateCompositeConstant(
const std::vector<uint32_t>& component_ids, uint32_t type_id,
bool is_irrelevant);
// Returns the result id of an instruction of the form:
// %id = OpUndef %|type_id|
// If no such instruction exists, a transformation is applied to add it.
uint32_t FindOrCreateGlobalUndef(uint32_t type_id);
// Returns the id of an OpNullConstant instruction of type |type_id|. If
// that instruction doesn't exist, it is added through a transformation.
// |type_id| must be a valid result id of an OpType* instruction that exists
// in the module.
uint32_t FindOrCreateNullConstant(uint32_t type_id);
// Define a *basic type* to be an integer, boolean or floating-point type,
// or a matrix, vector, struct or fixed-size array built from basic types. In
// particular, a basic type cannot contain an opaque type (such as an image),
// or a runtime-sized array.
//
// Yields a pair, (basic_type_ids, basic_type_ids_to_pointers), such that:
// - basic_type_ids captures every basic type declared in the module.
// - basic_type_ids_to_pointers maps every such basic type to the sequence
// of all pointer types that have storage class |storage_class| and the
// given basic type as their pointee type. The sequence may be empty for
// some basic types if no pointers to those types are defined for the given
// storage class, and the sequence will have multiple elements if there are
// repeated pointer declarations for the same basic type and storage class.
std::pair<std::vector<uint32_t>, std::map<uint32_t, std::vector<uint32_t>>>
GetAvailableBasicTypesAndPointers(SpvStorageClass storage_class) const;
// Given a type id, |scalar_or_composite_type_id|, which must correspond to
// some scalar or composite type, returns the result id of an instruction
// defining a constant of the given type that is zero or false at everywhere.
// If such an instruction does not yet exist, transformations are applied to
// add it. The returned id either participates in IdIsIrrelevant fact or not,
// depending on the |is_irrelevant| parameter.
//
// Examples:
// --------------+-------------------------------
// TYPE | RESULT is id corresponding to
// --------------+-------------------------------
// bool | false
// --------------+-------------------------------
// bvec4 | (false, false, false, false)
// --------------+-------------------------------
// float | 0.0
// --------------+-------------------------------
// vec2 | (0.0, 0.0)
// --------------+-------------------------------
// int[3] | [0, 0, 0]
// --------------+-------------------------------
// struct S { |
// int i; | S(0, false, (0u, 0u))
// bool b; |
// uint2 u; |
// } |
// --------------+-------------------------------
uint32_t FindOrCreateZeroConstant(uint32_t scalar_or_composite_type_id,
bool is_irrelevant);
// Adds a pair (id_use_descriptor, |replacement_id|) to the vector
// |uses_to_replace|, where id_use_descriptor is the id use descriptor
// representing the usage of an id in the |use_inst| instruction, at operand
// index |use_index|, only if the instruction is in a basic block.
// If the instruction is not in a basic block, it does nothing.
void MaybeAddUseToReplace(
opt::Instruction* use_inst, uint32_t use_index, uint32_t replacement_id,
std::vector<std::pair<protobufs::IdUseDescriptor, uint32_t>>*
uses_to_replace);
// Returns the preheader of the loop with header |header_id|, which satisfies
// all of the following conditions:
// - It is the only out-of-loop predecessor of the header
// - It unconditionally branches to the header
// - It is not a loop header itself
// If such preheader does not exist, a new one is added and returned.
// Requires |header_id| to be the label id of a loop header block that is
// reachable in the CFG (and thus has at least 2 predecessors).
opt::BasicBlock* GetOrCreateSimpleLoopPreheader(uint32_t header_id);
// Returns the second block in the pair obtained by splitting |block_id| just
// after the last OpPhi or OpVariable instruction in it. Assumes that the
// block is not a loop header.
opt::BasicBlock* SplitBlockAfterOpPhiOrOpVariable(uint32_t block_id);
// Returns the id of an available local variable (storage class Function) with
// the fact PointeeValueIsIrrelevant set according to
// |pointee_value_is_irrelevant|. If there is no such variable, it creates one
// in the |function| adding a zero initializer constant that is irrelevant.
// The new variable has the fact PointeeValueIsIrrelevant set according to
// |pointee_value_is_irrelevant|. The function returns the id of the created
// variable.
uint32_t FindOrCreateLocalVariable(uint32_t pointer_type_id,
uint32_t function_id,
bool pointee_value_is_irrelevant);
// Returns the id of an available global variable (storage class Private or
// Workgroup) with the fact PointeeValueIsIrrelevant set according to
// |pointee_value_is_irrelevant|. If there is no such variable, it creates
// one, adding a zero initializer constant that is irrelevant. The new
// variable has the fact PointeeValueIsIrrelevant set according to
// |pointee_value_is_irrelevant|. The function returns the id of the created
// variable.
uint32_t FindOrCreateGlobalVariable(uint32_t pointer_type_id,
bool pointee_value_is_irrelevant);
private:
opt::IRContext* ir_context_;
TransformationContext* transformation_context_;
FuzzerContext* fuzzer_context_;
protobufs::TransformationSequence* transformations_;
};
} // namespace fuzz
} // namespace spvtools
#endif // SOURCE_FUZZ_FUZZER_PASS_H_