# Copyright 2020 The IREE Authors
#
# Licensed under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

# iree_tablegen_doc()
#
# Runs iree-tablegen to produce documentation. For TableGen'ing others,
# please use iree_tablegen_library().
#
# One-value parameters:
# * NAME: base name of the target. The real target name is mangled from this
#         given name with the package name
# * CATEGORY: documentation category (`Dialects`, `Passes`, etc)
# * TBLGEN: the base project to pass to TableGen
#
# Multi-value parameters:
# * TD_FILE: Input .td files
# * OUTS: TableGen generator commands and their outputs in the format of
#         `-gen-<something> <output-file-name>`. Note that the generator
#         commands should only be for documentation.
function(iree_tablegen_doc)
  if(NOT IREE_BUILD_DOCS)
    return()
  endif()

  cmake_parse_arguments(
    _RULE
    ""
    "NAME;CATEGORY;TBLGEN"
    "TD_FILE;OUTS"
    ${ARGN}
  )

  # Prefix the library with the package name, so we get: iree_package_name
  iree_package_name(_PACKAGE_NAME)
  set(_NAME "${_PACKAGE_NAME}_${_RULE_NAME}")

  # Get tablegen executable and target based on TBLGEN parameter.
  if(${_RULE_TBLGEN} MATCHES "IREE")
    set(_TBLGEN_EXE ${IREE_TABLEGEN_EXE})
    set(_TBLGEN_TARGET ${IREE_TABLEGEN_TARGET})
  else()
    set(_TBLGEN_EXE ${MLIR_TABLEGEN_EXE})
    set(_TBLGEN_TARGET ${MLIR_TABLEGEN_TARGET})
  endif()

  set(_INCLUDE_DIRS
    "${MLIR_INCLUDE_DIRS}"
    "${IREE_SOURCE_DIR}/compiler/src"
    "${IREE_BINARY_DIR}/compiler/src"
  )
  list(APPEND _INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR})
  list(TRANSFORM _INCLUDE_DIRS PREPEND "-I")

  # Build absolute path for the main .td file.
  if(IS_ABSOLUTE ${_RULE_TD_FILE})
    set(_TD_FILE_ABS ${_RULE_TD_FILE})
  else()
    set(_TD_FILE_ABS ${CMAKE_CURRENT_SOURCE_DIR}/${_RULE_TD_FILE})
  endif()

  set(_FLAGS
    "--strip-prefix=::mlir::iree_compiler::IREE::"
  )

  set(_OUTPUTS)
  while(_RULE_OUTS)
    list(GET _RULE_OUTS 0 _COMMAND)
    list(REMOVE_AT _RULE_OUTS 0)
    list(LENGTH _RULE_OUTS _LEN)
    if(_LEN GREATER 1)
      list(GET _RULE_OUTS 0 _DIALECT)
      list(REMOVE_AT _RULE_OUTS 0)
    endif()
    list(GET _RULE_OUTS 0 _OUTPUT)
    list(REMOVE_AT _RULE_OUTS 0)

    set(_OUTPUT_FILE ${CMAKE_CURRENT_BINARY_DIR}/${_OUTPUT})

    # Create add_custom_command with depfile support for Ninja.
    if(CMAKE_GENERATOR MATCHES "Ninja")
      add_custom_command(
        OUTPUT ${_OUTPUT_FILE}
        COMMAND ${_TBLGEN_EXE} ${_COMMAND} ${_DIALECT} ${_INCLUDE_DIRS} ${_FLAGS} ${_TD_FILE_ABS}
                --write-if-changed -o ${_OUTPUT_FILE} -d ${_OUTPUT_FILE}.d
        DEPENDS ${_TBLGEN_TARGET} ${_TBLGEN_EXE} ${_TD_FILE_ABS}
        DEPFILE ${_OUTPUT_FILE}.d
        COMMENT "Building ${_OUTPUT}..."
        )
    else()
      add_custom_command(
        OUTPUT ${_OUTPUT_FILE}
        COMMAND ${_TBLGEN_EXE} ${_COMMAND} ${_DIALECT} ${_INCLUDE_DIRS} ${_FLAGS} ${_TD_FILE_ABS}
                --write-if-changed -o ${_OUTPUT_FILE}
        DEPENDS ${_TBLGEN_TARGET} ${_TBLGEN_EXE} ${_TD_FILE_ABS}
        COMMENT "Building ${_OUTPUT}..."
        )
    endif()

    list(APPEND _OUTPUTS ${_OUTPUT_FILE})
    set_source_files_properties(${_OUTPUT_FILE} PROPERTIES GENERATED 1)
  endwhile()

  # Put all dialect docs at one place.
  set(_DOC_DIR ${IREE_BINARY_DIR}/doc/${_RULE_CATEGORY}/)
  # Set a target to drive copy.
  add_custom_target(${_NAME}_target
            ${CMAKE_COMMAND} -E make_directory ${_DOC_DIR}
    COMMAND ${CMAKE_COMMAND} -E copy ${_OUTPUTS} ${_DOC_DIR}
    DEPENDS ${_OUTPUTS})
  set_target_properties(${_NAME}_target PROPERTIES FOLDER "Tablegenning")

  # Register this dialect doc to iree-doc.
  add_dependencies(iree-doc ${_NAME}_target)
endfunction()