# CMake file to replace the string contents in ONNX, Caffe, and Caffe2 proto.
# Usage example:
#   cmake -DFILENAME=caffe2.pb.h -DLOCAL_PROTOBUF=ON -P ProtoBufPatch.cmake

file(READ ${FILENAME} content)

if(NOT SYSTEM_PROTOBUF)
  # protobuf-3.6.0 pattern
  string(
    REPLACE
    "::google::protobuf::internal::GetEmptyStringAlreadyInited"
    "GetEmptyStringAlreadyInited"
    content
    "${content}")

  # protobuf-3.8.0+ pattern
  string(
    REPLACE
    "::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited"
    "GetEmptyStringAlreadyInited"
    content
    "${content}")

  string(
    REPLACE
    "PROTOBUF_CONSTEXPR"
    ""
    content
    "${content}")

  # https://github.com/protocolbuffers/protobuf/commit/0400cca3236de1ca303af38bf81eab332d042b7c
  # changes PROTOBUF_CONSTEXPR to constexpr, which breaks windows
  # build.
  string(
    REGEX REPLACE
    "static constexpr ([^ ]+) ([^ ]+) ="
    "static \\1 const \\2 ="
    content
    "${content}")

  foreach(ns ${NAMESPACES})
    # Insert "const ::std::string& GetEmptyStringAlreadyInited();" within
    # the namespace and make sure we only do it once in the file. Unfortunately
    # using string(REPLACE ...) doesn't work because it will replace at all
    # locations and there might be multiple declarations of the namespace
    # depending on how the proto is structured.
    set(search "namespace ${ns} {")
    string(LENGTH "${search}" search_len)
    string(FIND "${content}" "${search}" pos)
    if(${pos} GREATER -1)
      math(EXPR pos "${pos}+${search_len}")
      string(SUBSTRING "${content}" 0 ${pos} content_pre)
      string(SUBSTRING "${content}" ${pos} -1 content_post)
      string(
        CONCAT
        content
        "${content_pre}"
        " const ::std::string& GetEmptyStringAlreadyInited(); "
        "${content_post}")
    endif()
  endforeach()

  # The moving constructor is defined in the header file, which will cause
  # a link error that claims that the vftable is not found. Luckily, we
  # could move the definition into the source file to solve the problem.
  list(LENGTH NAMESPACES ns_count)
  if("${FILENAME}" MATCHES ".pb.h" AND ns_count EQUAL 1)
    string(REPLACE ".pb.h" ".pb.cc" SOURCE_FILENAME ${FILENAME})
    file(READ ${SOURCE_FILENAME} content_cc_origin)

    string(REGEX MATCHALL "([a-zA-Z_]+)\\([a-zA-Z_]+&& from\\) noexcept[^}]*}" content_cc "${content}")
    string(REGEX REPLACE "};" "}\n" content_cc "${content_cc}")
    string(REGEX REPLACE "([a-zA-Z_]+)\\([a-zA-Z_]+&& from\\) noexcept" "  \\1::\\1(\\1&& from) noexcept" content_cc "${content_cc}")
    set(content_cc "${content_cc_origin}\nnamespace ${NAMESPACES} {\n#if LANG_CXX11\n${content_cc}\n#endif\n}")

    string(REGEX REPLACE "([a-zA-Z_]+)\\([a-zA-Z_]+&& from\\) noexcept([^}]*)}" "\\1(\\1&& from) noexcept;" content "${content}")

    file(WRITE ${SOURCE_FILENAME} "${content_cc}")
  endif()
endif(NOT SYSTEM_PROTOBUF)

# constexpr int TensorBoundShape_DimType_DimType_ARRAYSIZE = TensorBoundShape_DimType_DimType_MAX + 1;
# throws
# error: more than one operator "+" matches these operands:
#     built-in operator "arithmetic + arithmetic"
#     function "c10::operator+(int, c10::BFloat16)"
#     function "c10::operator+(c10::BFloat16, int)"
#     function "c10::operator+(int, c10::Half)"
#     function "c10::operator+(c10::Half, int)"
#   operand types are: const caffe2::ExternalDataProto_SourceType + int
string(
  REGEX REPLACE
  "constexpr ([^ ]+) ([^ ]+_ARRAYSIZE) = ([^ ]+_MAX) \\+ 1;"
  "constexpr \\1 \\2 = static_cast<\\1>(\\3) + 1;"
  content
  "${content}")

file(WRITE ${FILENAME} "${content}")