// Copyright (c) 2015-2016 The Khronos Group Inc.
//
// 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 LIBSPIRV_VAL_VALIDATIONSTATE_H_
#define LIBSPIRV_VAL_VALIDATIONSTATE_H_

#include <deque>
#include <set>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#include "assembly_grammar.h"
#include "decoration.h"
#include "diagnostic.h"
#include "enum_set.h"
#include "latest_version_spirv_header.h"
#include "spirv-tools/libspirv.h"
#include "spirv_definition.h"
#include "val/function.h"
#include "val/instruction.h"

namespace libspirv {

/// This enum represents the sections of a SPIRV module. See section 2.4
/// of the SPIRV spec for additional details of the order. The enumerant values
/// are in the same order as the vector returned by GetModuleOrder
enum ModuleLayoutSection {
  kLayoutCapabilities,          /// < Section 2.4 #1
  kLayoutExtensions,            /// < Section 2.4 #2
  kLayoutExtInstImport,         /// < Section 2.4 #3
  kLayoutMemoryModel,           /// < Section 2.4 #4
  kLayoutEntryPoint,            /// < Section 2.4 #5
  kLayoutExecutionMode,         /// < Section 2.4 #6
  kLayoutDebug1,                /// < Section 2.4 #7 > 1
  kLayoutDebug2,                /// < Section 2.4 #7 > 2
  kLayoutDebug3,                /// < Section 2.4 #7 > 3
  kLayoutAnnotations,           /// < Section 2.4 #8
  kLayoutTypes,                 /// < Section 2.4 #9
  kLayoutFunctionDeclarations,  /// < Section 2.4 #10
  kLayoutFunctionDefinitions    /// < Section 2.4 #11
};

/// This class manages the state of the SPIR-V validation as it is being parsed.
class ValidationState_t {
 public:
  // Features that can optionally be turned on by a capability.
  struct Feature {
    bool declare_int16_type = false;     // Allow OpTypeInt with 16 bit width?
    bool declare_float16_type = false;   // Allow OpTypeFloat with 16 bit width?
    bool free_fp_rounding_mode = false;  // Allow the FPRoundingMode decoration
                                         // and its vaules to be used without
                                         // requiring any capability

    // Allow functionalities enabled by VariablePointers capability.
    bool variable_pointers = false;
    // Allow functionalities enabled by VariablePointersStorageBuffer
    // capability.
    bool variable_pointers_storage_buffer = false;

    // Permit group oerations Reduce, InclusiveScan, ExclusiveScan
    bool group_ops_reduce_and_scans = false;
  };

  ValidationState_t(const spv_const_context context,
                    const spv_const_validator_options opt);

  /// Returns the context
  spv_const_context context() const { return context_; }

  /// Returns the command line options
  spv_const_validator_options options() const { return options_; }

  /// Forward declares the id in the module
  spv_result_t ForwardDeclareId(uint32_t id);

  /// Removes a forward declared ID if it has been defined
  spv_result_t RemoveIfForwardDeclared(uint32_t id);

  /// Registers an ID as a forward pointer
  spv_result_t RegisterForwardPointer(uint32_t id);

  /// Returns whether or not an ID is a forward pointer
  bool IsForwardPointer(uint32_t id) const;

  /// Assigns a name to an ID
  void AssignNameToId(uint32_t id, std::string name);

  /// Returns a string representation of the ID in the format <id>[Name] where
  /// the <id> is the numeric valid of the id and the Name is a name assigned by
  /// the OpName instruction
  std::string getIdName(uint32_t id) const;

  /// Accessor function for ID bound.
  uint32_t getIdBound() const;

  /// Mutator function for ID bound.
  void setIdBound(uint32_t bound);

  /// Like getIdName but does not display the id if the \p id has a name
  std::string getIdOrName(uint32_t id) const;

  /// Returns the number of ID which have been forward referenced but not
  /// defined
  size_t unresolved_forward_id_count() const;

  /// Returns a vector of unresolved forward ids.
  std::vector<uint32_t> UnresolvedForwardIds() const;

  /// Returns true if the id has been defined
  bool IsDefinedId(uint32_t id) const;

  /// Increments the instruction count. Used for diagnostic
  int increment_instruction_count();

  /// Returns the current layout section which is being processed
  ModuleLayoutSection current_layout_section() const;

  /// Increments the module_layout_order_section_
  void ProgressToNextLayoutSectionOrder();

  /// Determines if the op instruction is part of the current section
  bool IsOpcodeInCurrentLayoutSection(SpvOp op);

  libspirv::DiagnosticStream diag(spv_result_t error_code) const;

  /// Returns the function states
  std::deque<Function>& functions();

  /// Returns the function states
  Function& current_function();
  const Function& current_function() const;

  /// Returns function state with the given id, or nullptr if no such function.
  const Function* function(uint32_t id) const;

  /// Returns true if the called after a function instruction but before the
  /// function end instruction
  bool in_function_body() const;

  /// Returns true if called after a label instruction but before a branch
  /// instruction
  bool in_block() const;

  struct EntryPointDescription {
    std::string name;
    std::vector<uint32_t> interfaces;
  };

  /// Registers |id| as an entry point with |execution_model| and |interfaces|.
  void RegisterEntryPoint(const uint32_t id, SpvExecutionModel execution_model,
                          EntryPointDescription&& desc) {
    entry_points_.push_back(id);
    entry_point_to_execution_models_[id].insert(execution_model);
    entry_point_descriptions_[id].emplace_back(desc);
  }

  /// Returns a list of entry point function ids
  const std::vector<uint32_t>& entry_points() const { return entry_points_; }

  /// Registers execution mode for the given entry point.
  void RegisterExecutionModeForEntryPoint(uint32_t entry_point,
                                          SpvExecutionMode execution_mode) {
    entry_point_to_execution_modes_[entry_point].insert(execution_mode);
  }

  /// Returns the interface descriptions of a given entry point.
  const std::vector<EntryPointDescription>& entry_point_descriptions(
      uint32_t entry_point) {
    return entry_point_descriptions_.at(entry_point);
  }

  /// Returns Execution Models for the given Entry Point.
  /// Returns nullptr if none found (would trigger assertion).
  const std::set<SpvExecutionModel>* GetExecutionModels(
      uint32_t entry_point) const {
    const auto it = entry_point_to_execution_models_.find(entry_point);
    if (it == entry_point_to_execution_models_.end()) {
      assert(0);
      return nullptr;
    }
    return &it->second;
  }

  /// Returns Execution Modes for the given Entry Point.
  /// Returns nullptr if none found.
  const std::set<SpvExecutionMode>* GetExecutionModes(
      uint32_t entry_point) const {
    const auto it = entry_point_to_execution_modes_.find(entry_point);
    if (it == entry_point_to_execution_modes_.end()) {
      return nullptr;
    }
    return &it->second;
  }

  /// Traverses call tree and computes function_to_entry_points_.
  /// Note: called after fully parsing the binary.
  void ComputeFunctionToEntryPointMapping();

  /// Returns all the entry points that can call |func|.
  const std::vector<uint32_t>& FunctionEntryPoints(uint32_t func) const;

  /// Inserts an <id> to the set of functions that are target of OpFunctionCall.
  void AddFunctionCallTarget(const uint32_t id) {
    function_call_targets_.insert(id);
    current_function().AddFunctionCallTarget(id);
  }

  /// Returns whether or not a function<id> is the target of OpFunctionCall.
  bool IsFunctionCallTarget(const uint32_t id) {
    return (function_call_targets_.find(id) != function_call_targets_.end());
  }

  /// Registers the capability and its dependent capabilities
  void RegisterCapability(SpvCapability cap);

  /// Registers the extension.
  void RegisterExtension(Extension ext);

  /// Registers the function in the module. Subsequent instructions will be
  /// called against this function
  spv_result_t RegisterFunction(uint32_t id, uint32_t ret_type_id,
                                SpvFunctionControlMask function_control,
                                uint32_t function_type_id);

  /// Register a function end instruction
  spv_result_t RegisterFunctionEnd();

  /// Returns true if the capability is enabled in the module.
  bool HasCapability(SpvCapability cap) const {
    return module_capabilities_.Contains(cap);
  }

  /// Returns true if the extension is enabled in the module.
  bool HasExtension(Extension ext) const {
    return module_extensions_.Contains(ext);
  }

  /// Returns true if any of the capabilities is enabled, or if |capabilities|
  /// is an empty set.
  bool HasAnyOfCapabilities(const libspirv::CapabilitySet& capabilities) const;

  /// Returns true if any of the extensions is enabled, or if |extensions|
  /// is an empty set.
  bool HasAnyOfExtensions(const libspirv::ExtensionSet& extensions) const;

  /// Sets the addressing model of this module (logical/physical).
  void set_addressing_model(SpvAddressingModel am);

  /// Returns true if the OpMemoryModel was found.
  bool has_memory_model_specified() const {
    return addressing_model_ != SpvAddressingModelMax &&
           memory_model_ != SpvMemoryModelMax;
  }

  /// Returns the addressing model of this module, or Logical if uninitialized.
  SpvAddressingModel addressing_model() const;

  /// Sets the memory model of this module.
  void set_memory_model(SpvMemoryModel mm);

  /// Returns the memory model of this module, or Simple if uninitialized.
  SpvMemoryModel memory_model() const;

  const AssemblyGrammar& grammar() const { return grammar_; }

  /// Registers the instruction
  void RegisterInstruction(const spv_parsed_instruction_t& inst);

  /// Registers the decoration for the given <id>
  void RegisterDecorationForId(uint32_t id, const Decoration& dec) {
    id_decorations_[id].push_back(dec);
  }

  /// Registers the list of decorations for the given <id>
  template <class InputIt>
  void RegisterDecorationsForId(uint32_t id, InputIt begin, InputIt end) {
    std::vector<Decoration>& cur_decs = id_decorations_[id];
    cur_decs.insert(cur_decs.end(), begin, end);
  }

  /// Registers the list of decorations for the given member of the given
  /// structure.
  template <class InputIt>
  void RegisterDecorationsForStructMember(uint32_t struct_id,
                                          uint32_t member_index, InputIt begin,
                                          InputIt end) {
    RegisterDecorationsForId(struct_id, begin, end);
    for (auto& decoration : id_decorations_[struct_id]) {
      decoration.set_struct_member_index(member_index);
    }
  }

  /// Returns all the decorations for the given <id>. If no decorations exist
  /// for the <id>, it registers an empty vector for it in the map and
  /// returns the empty vector.
  std::vector<Decoration>& id_decorations(uint32_t id) {
    return id_decorations_[id];
  }
  const std::vector<Decoration>& id_decorations(uint32_t id) const {
    // TODO: This would throw or generate SIGABRT if id has no
    // decorations. Remove/refactor this function.
    return id_decorations_.at(id);
  }

  // Returns const pointer to the internal decoration container.
  const std::map<uint32_t, std::vector<Decoration>>& id_decorations() const {
    return id_decorations_;
  }

  /// Finds id's def, if it exists.  If found, returns the definition otherwise
  /// nullptr
  const Instruction* FindDef(uint32_t id) const;

  /// Finds id's def, if it exists.  If found, returns the definition otherwise
  /// nullptr
  Instruction* FindDef(uint32_t id);

  /// Returns a deque of instructions in the order they appear in the binary
  const std::deque<Instruction>& ordered_instructions() const {
    return ordered_instructions_;
  }

  /// Returns a map of instructions mapped by their result id
  const std::unordered_map<uint32_t, Instruction*>& all_definitions() const {
    return all_definitions_;
  }

  /// Returns a vector containing the Ids of instructions that consume the given
  /// SampledImage id.
  std::vector<uint32_t> getSampledImageConsumers(uint32_t id) const;

  /// Records cons_id as a consumer of sampled_image_id.
  void RegisterSampledImageConsumer(uint32_t sampled_image_id,
                                    uint32_t cons_id);

  /// Returns the set of Global Variables.
  std::unordered_set<uint32_t>& global_vars() { return global_vars_; }

  /// Returns the set of Local Variables.
  std::unordered_set<uint32_t>& local_vars() { return local_vars_; }

  /// Returns the number of Global Variables.
  size_t num_global_vars() { return global_vars_.size(); }

  /// Returns the number of Local Variables.
  size_t num_local_vars() { return local_vars_.size(); }

  /// Inserts a new <id> to the set of Global Variables.
  void registerGlobalVariable(const uint32_t id) { global_vars_.insert(id); }

  /// Inserts a new <id> to the set of Local Variables.
  void registerLocalVariable(const uint32_t id) { local_vars_.insert(id); }

  /// Sets the struct nesting depth for a given struct ID
  void set_struct_nesting_depth(uint32_t id, uint32_t depth) {
    struct_nesting_depth_[id] = depth;
  }

  /// Returns the nesting depth of a given structure ID
  uint32_t struct_nesting_depth(uint32_t id) {
    return struct_nesting_depth_[id];
  }

  /// Records that the structure type has a member decorated with a built-in.
  void RegisterStructTypeWithBuiltInMember(uint32_t id) {
    builtin_structs_.insert(id);
  }

  /// Returns true if the struct type with the given Id has a BuiltIn member.
  bool IsStructTypeWithBuiltInMember(uint32_t id) const {
    return (builtin_structs_.find(id) != builtin_structs_.end());
  }

  // Returns the state of optional features.
  const Feature& features() const { return features_; }

  /// Adds the instruction data to unique_type_declarations_.
  /// Returns false if an identical type declaration already exists.
  bool RegisterUniqueTypeDeclaration(const spv_parsed_instruction_t& inst);

  // Returns type_id of the scalar component of |id|.
  // |id| can be either
  // - scalar, vector or matrix type
  // - object of either scalar, vector or matrix type
  uint32_t GetComponentType(uint32_t id) const;

  // Returns
  // - 1 for scalar types or objects
  // - vector size for vector types or objects
  // - num columns for matrix types or objects
  // Should not be called with any other arguments (will return zero and invoke
  // assertion).
  uint32_t GetDimension(uint32_t id) const;

  // Returns bit width of scalar or component.
  // |id| can be
  // - scalar, vector or matrix type
  // - object of either scalar, vector or matrix type
  // Will invoke assertion and return 0 if |id| is none of the above.
  uint32_t GetBitWidth(uint32_t id) const;

  // Provides detailed information on matrix type.
  // Returns false iff |id| is not matrix type.
  bool GetMatrixTypeInfo(uint32_t id, uint32_t* num_rows, uint32_t* num_cols,
                         uint32_t* column_type, uint32_t* component_type) const;

  // Collects struct member types into |member_types|.
  // Returns false iff not struct type or has no members.
  // Deletes prior contents of |member_types|.
  bool GetStructMemberTypes(uint32_t struct_type_id,
                            std::vector<uint32_t>* member_types) const;

  // Returns true iff |id| is a type corresponding to the name of the function.
  // Only works for types not for objects.
  bool IsFloatScalarType(uint32_t id) const;
  bool IsFloatVectorType(uint32_t id) const;
  bool IsFloatScalarOrVectorType(uint32_t id) const;
  bool IsFloatMatrixType(uint32_t id) const;
  bool IsIntScalarType(uint32_t id) const;
  bool IsIntVectorType(uint32_t id) const;
  bool IsIntScalarOrVectorType(uint32_t id) const;
  bool IsUnsignedIntScalarType(uint32_t id) const;
  bool IsUnsignedIntVectorType(uint32_t id) const;
  bool IsSignedIntScalarType(uint32_t id) const;
  bool IsSignedIntVectorType(uint32_t id) const;
  bool IsBoolScalarType(uint32_t id) const;
  bool IsBoolVectorType(uint32_t id) const;
  bool IsBoolScalarOrVectorType(uint32_t id) const;
  bool IsPointerType(uint32_t id) const;

  // Gets value from OpConstant and OpSpecConstant as uint64.
  // Returns false on failure (no instruction, wrong instruction, not int).
  bool GetConstantValUint64(uint32_t id, uint64_t* val) const;

  // Returns type_id if id has type or zero otherwise.
  uint32_t GetTypeId(uint32_t id) const;

  // Returns opcode of the instruction which issued the id or OpNop if the
  // instruction is not registered.
  SpvOp GetIdOpcode(uint32_t id) const;

  // Returns type_id for given id operand if it has a type or zero otherwise.
  // |operand_index| is expected to be pointing towards an operand which is an
  // id.
  uint32_t GetOperandTypeId(const spv_parsed_instruction_t* inst,
                            size_t operand_index) const;

  // Provides information on pointer type. Returns false iff not pointer type.
  bool GetPointerTypeInfo(uint32_t id, uint32_t* data_type,
                          uint32_t* storage_class) const;

  // Tries to evaluate a 32-bit signed or unsigned scalar integer constant.
  // Returns tuple <is_int32, is_const_int32, value>.
  std::tuple<bool, bool, uint32_t> EvalInt32IfConst(uint32_t id);

 private:
  ValidationState_t(const ValidationState_t&);

  const spv_const_context context_;

  /// Stores the Validator command line options. Must be a valid options object.
  const spv_const_validator_options options_;

  /// Tracks the number of instructions evaluated by the validator
  int instruction_counter_;

  /// IDs which have been forward declared but have not been defined
  std::unordered_set<uint32_t> unresolved_forward_ids_;

  /// IDs that have been declared as forward pointers.
  std::unordered_set<uint32_t> forward_pointer_ids_;

  /// Stores a vector of instructions that use the result of a given
  /// OpSampledImage instruction.
  std::unordered_map<uint32_t, std::vector<uint32_t>> sampled_image_consumers_;

  /// A map of operand IDs and their names defined by the OpName instruction
  std::unordered_map<uint32_t, std::string> operand_names_;

  /// The section of the code being processed
  ModuleLayoutSection current_layout_section_;

  /// A list of functions in the module.
  /// Pointers to objects in this container are guaranteed to be stable and
  /// valid until the end of lifetime of the validation state.
  std::deque<Function> module_functions_;

  /// Capabilities declared in the module
  libspirv::CapabilitySet module_capabilities_;

  /// Extensions declared in the module
  libspirv::ExtensionSet module_extensions_;

  /// List of all instructions in the order they appear in the binary
  /// Pointers to objects in this container are guaranteed to be stable and
  /// valid until the end of lifetime of the validation state.
  std::deque<Instruction> ordered_instructions_;

  /// Instructions that can be referenced by Ids
  std::unordered_map<uint32_t, Instruction*> all_definitions_;

  /// IDs that are entry points, ie, arguments to OpEntryPoint.
  std::vector<uint32_t> entry_points_;

  /// Maps an entry point id to its desciptions.
  std::unordered_map<uint32_t, std::vector<EntryPointDescription>>
      entry_point_descriptions_;

  /// Functions IDs that are target of OpFunctionCall.
  std::unordered_set<uint32_t> function_call_targets_;

  /// ID Bound from the Header
  uint32_t id_bound_;

  /// Set of Global Variable IDs (Storage Class other than 'Function')
  std::unordered_set<uint32_t> global_vars_;

  /// Set of Local Variable IDs ('Function' Storage Class)
  std::unordered_set<uint32_t> local_vars_;

  /// Set of struct types that have members with a BuiltIn decoration.
  std::unordered_set<uint32_t> builtin_structs_;

  /// Structure Nesting Depth
  std::unordered_map<uint32_t, uint32_t> struct_nesting_depth_;

  /// Stores the list of decorations for a given <id>
  std::map<uint32_t, std::vector<Decoration>> id_decorations_;

  /// Stores type declarations which need to be unique (i.e. non-aggregates),
  /// in the form [opcode, operand words], result_id is not stored.
  /// Using ordered set to avoid the need for a vector hash function.
  /// The size of this container is expected not to exceed double-digits.
  std::set<std::vector<uint32_t>> unique_type_declarations_;

  AssemblyGrammar grammar_;

  SpvAddressingModel addressing_model_;
  SpvMemoryModel memory_model_;

  /// NOTE: See correspoding getter functions
  bool in_function_;

  /// The state of optional features.  These are determined by capabilities
  /// declared by the module.
  Feature features_;

  /// Maps function ids to function stat objects.
  std::unordered_map<uint32_t, Function*> id_to_function_;

  /// Mapping entry point -> execution models. It is presumed that the same
  /// function could theoretically be used as 'main' by multiple OpEntryPoint
  /// instructions.
  std::unordered_map<uint32_t, std::set<SpvExecutionModel>>
      entry_point_to_execution_models_;

  /// Mapping entry point -> execution modes.
  std::unordered_map<uint32_t, std::set<SpvExecutionMode>>
      entry_point_to_execution_modes_;

  /// Mapping function -> array of entry points inside this
  /// module which can (indirectly) call the function.
  std::unordered_map<uint32_t, std::vector<uint32_t>> function_to_entry_points_;
  const std::vector<uint32_t> empty_ids_;
};

}  // namespace libspirv

#endif  /// LIBSPIRV_VAL_VALIDATIONSTATE_H_