// Copyright (c) 2016 Google 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 SOURCE_NAME_MAPPER_H_

#define SOURCE_NAME_MAPPER_H_

#include <functional>

#include <string>

#include <unordered_map>

#include <unordered_set>

#include "source/assembly_grammar.h"

#include "spirv-tools/libspirv.h"

namespace spvtools {

// A NameMapper maps SPIR-V Id values to names.  Each name is valid to use in

// SPIR-V assembly.  The mapping is one-to-one, i.e. no two Ids map to the same

// name.

using NameMapper = std::function<std::string(uint32_t)>;

// Returns a NameMapper which always maps an Id to its decimal representation.

NameMapper GetTrivialNameMapper();

// A FriendlyNameMapper parses a module upon construction.  If the parse is

// successful, then the NameForId method maps an Id to a friendly name

// while also satisfying the constraints on a NameMapper.

//

// The mapping is friendly in the following sense:

//  - If an Id has a debug name (via OpName), then that will be used when

//    possible.

//  - Well known scalar types map to friendly names.  For example,

//    OpTypeVoid should be %void.  Scalar types map to their names in OpenCL

//    when

//    there is a correspondence, and otherwise as follows:

//    - unsigned integer type of n bits map to "u" followed by n

//    - signed integer type of n bits map to "i" followed by n

//    - floating point type of n bits map to "fp" followed by n

//  - Vector type names map to "v" followed by the number of components,

//    followed by the friendly name for the base type.

//  - Matrix type names map to "mat" followed by the number of columns,

//    followed by the friendly name for the base vector type.

//  - Pointer types map to "_ptr_", then the name of the storage class, then the

//    name for the pointee type.

//  - Exotic types like event, pipe, opaque, queue, reserve-id map to their own

//    human readable names.

//  - A struct type maps to "_struct_" followed by the raw Id number.  That's

//    pretty simplistic, but workable.

//  - A built-in variable maps to its GLSL variable name.

//  - Numeric literals in OpConstant map to a human-friendly name.

class FriendlyNameMapper {

 public:

  // Construct a friendly name mapper, and determine friendly names for each

  // defined Id in the specified module.  The module is specified by the code

  // wordCount, and should be parseable in the specified context.  The options

  // bitmask is passed to the binary parser; pass

  // SPV_BINARY_TO_TEXT_OPTION_HANDLE_UNKNOWN_OPCODES to tolerate unknown

  // opcodes in the module.

  FriendlyNameMapper(const spv_const_context context, const uint32_t* code,

                     const size_t wordCount, uint32_t options = 0);

  // Returns a NameMapper which maps ids to the friendly names parsed from the

  // module provided to the constructor.

  NameMapper GetNameMapper() {

    return [this](uint32_t id) { return this->NameForId(id); };

  }

  // Returns the friendly name for the given id.  If the module parsed during

  // construction is valid, then the mapping satisfies the rules for a

  // NameMapper.

  std::string NameForId(uint32_t id);

 private:

  // Transforms the given string so that it is acceptable as an Id name in

  // assembly language.  Two distinct inputs can map to the same output.

  std::string Sanitize(const std::string& suggested_name);

  // Records a name for the given id.  If this id already has a name, then

  // this is a no-op.  If the id doesn't have a name, use the given

  // suggested_name if it hasn't already been taken, and otherwise generate

  // a new (unused) name based on the suggested name.

  void SaveName(uint32_t id, const std::string& suggested_name);

  // Records a built-in variable name for target_id.  If target_id already

  // has a name then this is a no-op.

  void SaveBuiltInName(uint32_t target_id, uint32_t built_in);

  // Collects information from the given parsed instruction to populate

  // name_for_id_.  Returns SPV_SUCCESS;

  spv_result_t ParseInstruction(const spv_parsed_instruction_t& inst);

  // Forwards a parsed-instruction callback from the binary parser into the

  // FriendlyNameMapper hidden inside the user_data parameter.

  static spv_result_t ParseInstructionForwarder(

      void* user_data, const spv_parsed_instruction_t* parsed_instruction) {

    return reinterpret_cast<FriendlyNameMapper*>(user_data)->ParseInstruction(

        *parsed_instruction);

  }

  // Returns the friendly name for an enumerant.

  std::string NameForEnumOperand(spv_operand_type_t type, uint32_t word);

  // Maps an id to its friendly name.  This will have an entry for each Id

  // defined in the module.

  std::unordered_map<uint32_t, std::string> name_for_id_;

  // The set of names that have a mapping in name_for_id_;

  std::unordered_set<std::string> used_names_;

  // The assembly grammar for the current context.

  const AssemblyGrammar grammar_;

};

}  // namespace spvtools

#endif  // SOURCE_NAME_MAPPER_H_