CMake/Modules/CMakeParseImplicitLinkInfo.cmake

# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.

cmake_policy(PUSH)
cmake_policy(SET CMP0053 NEW)
cmake_policy(SET CMP0054 NEW)

# Function to parse implicit linker options.
#
# This is used internally by CMake and should not be included by user
# code.
#
# Note: this function is leaked/exposed by FindOpenMP and therefore needs
# to have a stable API so projects that copied `FindOpenMP` for backwards
# compatibility don't break.
#
function(CMAKE_PARSE_IMPLICIT_LINK_INFO text lib_var dir_var fwk_var log_var obj_regex)
  set(implicit_libs_tmp "")
  set(implicit_objs_tmp "")
  set(implicit_dirs_tmp)
  set(implicit_fwks_tmp)
  set(log "")

  set(keywordArgs)
  set(oneValueArgs COMPUTE_IMPLICIT_OBJECTS)
  set(multiValueArgs )
  cmake_parse_arguments(EXTRA_PARSE "${keywordArgs}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})

  # Parse implicit linker arguments.
  set(linker "CMAKE_LINKER-NOTFOUND")
  if(CMAKE_LINKER)
    get_filename_component(linker ${CMAKE_LINKER} NAME)
    string(REGEX REPLACE "([][+.*?()^$])" "\\\\\\1" linker "${linker}")
  endif()
  set(startfile "CMAKE_LINK_STARTFILE-NOTFOUND")
  if(CMAKE_LINK_STARTFILE)
    set(startfile "${CMAKE_LINK_STARTFILE}")
  endif()
  # Construct a regex to match linker lines.  It must match both the
  # whole line and just the command (argv[0]).
  set(linker_regex "^( *|.*[/\\])(${linker}|${startfile}|([^/\\]+-)?ld|collect2)[^/\\]*( |$)")
  set(linker_exclude_regex "collect2 version |^[A-Za-z0-9_]+=|/ldfe ")
  string(APPEND log "  link line regex: [${linker_regex}]\n")
  string(REGEX REPLACE "\r?\n" ";" output_lines "${text}")
  foreach(line IN LISTS output_lines)
    set(cmd)
    if("${line}" MATCHES "${linker_regex}" AND
        NOT "${line}" MATCHES "${linker_exclude_regex}")
      if(XCODE)
        # Xcode unconditionally adds a path under the project build tree and
        # on older versions it is not reported with proper quotes.  Remove it.
        string(REGEX REPLACE "([][+.*()^])" "\\\\\\1" _dir_regex "${CMAKE_BINARY_DIR}")
        string(REGEX REPLACE " -[FL]${_dir_regex}/([^ ]| [^-])+( |$)" " " xline "${line}")
        if(NOT "x${xline}" STREQUAL "x${line}")
          string(APPEND log "  reduced line: [${line}]\n            to: [${xline}]\n")
          set(line "${xline}")
        endif()
      endif()
      separate_arguments(args NATIVE_COMMAND "${line}")
      list(GET args 0 cmd)
      if("${cmd}" MATCHES "->")
        # LCC has '-> ' in-front of the linker
        list(GET args 1 cmd)
      endif()
    else()
      #check to see if the link line is comma-separated instead of space separated
      string(REGEX REPLACE "," " " line "${line}")
      if("${line}" MATCHES "${linker_regex}" AND
        NOT "${line}" MATCHES "${linker_exclude_regex}")
        separate_arguments(args NATIVE_COMMAND "${line}")
        list(GET args 0 cmd)
        if("${cmd}" MATCHES "exec:")
          # ibm xl sometimes has 'exec: ' in-front of the linker
          list(GET args 1 cmd)
        endif()
      endif()
    endif()
    set(is_msvc 0)
    set(search_static 0)
    if("${cmd}" MATCHES "${linker_regex}")
      string(APPEND log "  link line: [${line}]\n")
      string(REGEX REPLACE ";-([LYz]);" ";-\\1" args "${args}")
      set(skip_value_of "")
      foreach(arg IN LISTS args)
        if(skip_value_of)
          string(APPEND log "    arg [${arg}] ==> skip value of ${skip_value_of}\n")
          set(skip_value_of "")
        elseif("${arg}" MATCHES "^-L(.:)?[/\\]")
          # Unix search path.
          string(REGEX REPLACE "^-L" "" dir "${arg}")
          list(APPEND implicit_dirs_tmp ${dir})
          string(APPEND log "    arg [${arg}] ==> dir [${dir}]\n")
        elseif("${arg}" MATCHES "^[-/](LIBPATH|libpath):(.+)")
          # MSVC search path.
          set(dir "${CMAKE_MATCH_2}")
          list(APPEND implicit_dirs_tmp ${dir})
          string(APPEND log "    arg [${arg}] ==> dir [${dir}]\n")
        elseif(is_msvc AND "${arg}" STREQUAL "-link")
          string(APPEND log "    arg [${arg}] ==> ignore MSVC cl option\n")
        elseif(is_msvc AND "${arg}" MATCHES "^(.*\\.[Ll][Ii][Bb])$")
          set(lib "${CMAKE_MATCH_1}")
          list(APPEND implicit_libs_tmp ${lib})
          string(APPEND log "    arg [${arg}] ==> lib [${lib}]\n")
        elseif("${arg}" STREQUAL "-lto_library")
          # ld argument "-lto_library <path>"
          set(skip_value_of "${arg}")
          string(APPEND log "    arg [${arg}] ==> ignore, skip following value\n")
        elseif("${arg}" MATCHES "^-l([^:].*)$")
          # Unix library.
          set(lib "${CMAKE_MATCH_1}")
          if(search_static AND lib MATCHES "^(gfortran|stdc\\+\\+)$")
            # Search for the static library later, once all link dirs are known.
            set(lib "SEARCH_STATIC:${lib}")
          endif()
          list(APPEND implicit_libs_tmp ${lib})
          string(APPEND log "    arg [${arg}] ==> lib [${lib}]\n")
        elseif("${arg}" MATCHES "^(.:)?[/\\].*\\.a$")
          # Unix library full path.
          list(APPEND implicit_libs_tmp ${arg})
          string(APPEND log "    arg [${arg}] ==> lib [${arg}]\n")
        elseif("${arg}" MATCHES "^[-/](DEFAULTLIB|defaultlib):(.+)")
          # Windows library.
          set(lib "${CMAKE_MATCH_2}")
          list(APPEND implicit_libs_tmp ${lib})
          string(APPEND log "    arg [${arg}] ==> lib [${lib}]\n")
        elseif("${arg}" MATCHES "^(.:)?[/\\].*\\.o$")
          if(EXTRA_PARSE_COMPUTE_IMPLICIT_OBJECTS)
            list(APPEND implicit_objs_tmp ${arg})
            string(APPEND log "    arg [${arg}] ==> obj [${arg}]\n")
          endif()
          if(obj_regex AND "${arg}" MATCHES "${obj_regex}")
            # Object file full path.
            list(APPEND implicit_libs_tmp ${arg})
          endif()
        elseif("${arg}" MATCHES "^-Y(P,)?[^0-9]")
          # Sun search path ([^0-9] avoids conflict with Mac -Y<num>).
          string(REGEX REPLACE "^-Y(P,)?" "" dirs "${arg}")
          string(REPLACE ":" ";" dirs "${dirs}")
          list(APPEND implicit_dirs_tmp ${dirs})
          string(APPEND log "    arg [${arg}] ==> dirs [${dirs}]\n")
        elseif("${arg}" STREQUAL "-Bstatic")
          set(search_static 1)
          string(APPEND log "    arg [${arg}] ==> search static\n" )
        elseif("${arg}" STREQUAL "-Bdynamic")
          set(search_static 0)
          string(APPEND log "    arg [${arg}] ==> search dynamic\n" )
        elseif("${arg}" MATCHES "^-l:")
          # HP named library.
          list(APPEND implicit_libs_tmp ${arg})
          string(APPEND log "    arg [${arg}] ==> lib [${arg}]\n")
        elseif("${arg}" MATCHES "^-z(all|default|weak)extract")
          # Link editor option.
          list(APPEND implicit_libs_tmp ${arg})
          string(APPEND log "    arg [${arg}] ==> opt [${arg}]\n")
        elseif("${arg}" STREQUAL "cl.exe")
          string(APPEND log "    arg [${arg}] ==> recognize MSVC cl\n")
          set(is_msvc 1)
        else()
          string(APPEND log "    arg [${arg}] ==> ignore\n")
        endif()
      endforeach()
      break()
    elseif("${line}" MATCHES "LPATH(=| is:? *)(.*)$")
      string(APPEND log "  LPATH line: [${line}]\n")
      # HP search path.
      string(REPLACE ":" ";" paths "${CMAKE_MATCH_2}")
      list(APPEND implicit_dirs_tmp ${paths})
      string(APPEND log "    dirs [${paths}]\n")
    else()
      string(APPEND log "  ignore line: [${line}]\n")
    endif()
  endforeach()

  # Look for library search paths reported by linker.
  if("${output_lines}" MATCHES ";Library search paths:((;\t[^;]+)+)")
    string(REPLACE ";\t" ";" implicit_dirs_match "${CMAKE_MATCH_1}")
    string(APPEND log "  Library search paths: [${implicit_dirs_match}]\n")
    list(APPEND implicit_dirs_tmp ${implicit_dirs_match})
  endif()
  if("${output_lines}" MATCHES ";Framework search paths:((;\t[^;]+)+)")
    string(REPLACE ";\t" ";" implicit_fwks_match "${CMAKE_MATCH_1}")
    string(APPEND log "  Framework search paths: [${implicit_fwks_match}]\n")
    list(APPEND implicit_fwks_tmp ${implicit_fwks_match})
  endif()

  # Cleanup list of libraries and flags.
  # We remove items that are not language-specific.
  set(implicit_libs "")
  foreach(lib IN LISTS implicit_libs_tmp)
    if("x${lib}" MATCHES "^xSEARCH_STATIC:(.*)")
      set(search_static 1)
      set(lib "${CMAKE_MATCH_1}")
    else()
      set(search_static 0)
    endif()
    if("x${lib}" MATCHES "^x(crt.*\\.o|gcc_eh.*|.*libgcc_eh.*|System.*|.*libclang_rt.*|msvcrt.*|libvcruntime.*|libucrt.*|libcmt.*)$")
      string(APPEND log "  remove lib [${lib}]\n")
    elseif(search_static)
      # This library appears after a -Bstatic flag.  Due to ordering
      # and filtering for mixed-language link lines, we do not preserve
      # the -Bstatic flag itself.  Instead, use an absolute path.
      # Search using a temporary variable with a distinct name
      # so that our test suite does not depend on disk content.
      find_library("CMAKE_${lang}_IMPLICIT_LINK_LIBRARY_${lib}" NO_CACHE NAMES "lib${lib}.a" NO_DEFAULT_PATH PATHS ${implicit_dirs_tmp})
      set(_lib_static "${CMAKE_${lang}_IMPLICIT_LINK_LIBRARY_${lib}}")
      if(_lib_static)
        string(APPEND log "  search lib [SEARCH_STATIC:${lib}] ==> [${_lib_static}]\n")
        list(APPEND implicit_libs "${_lib_static}")
      else()
        string(APPEND log "  search lib [SEARCH_STATIC:${lib}] ==> [${lib}]\n")
        list(APPEND implicit_libs "${lib}")
      endif()
    elseif(IS_ABSOLUTE "${lib}")
      get_filename_component(abs "${lib}" ABSOLUTE)
      if(NOT "x${lib}" STREQUAL "x${abs}")
        string(APPEND log "  collapse lib [${lib}] ==> [${abs}]\n")
      endif()
      list(APPEND implicit_libs "${abs}")
    else()
      list(APPEND implicit_libs "${lib}")
    endif()
  endforeach()

  if(EXTRA_PARSE_COMPUTE_IMPLICIT_OBJECTS)
    set(implicit_objs "")
    foreach(obj IN LISTS implicit_objs_tmp)
      if(IS_ABSOLUTE "${obj}")
        get_filename_component(abs "${obj}" ABSOLUTE)
        if(NOT "x${obj}" STREQUAL "x${abs}")
          string(APPEND log "  collapse obj [${obj}] ==> [${abs}]\n")
        endif()
        list(APPEND implicit_objs "${abs}")
      else()
        list(APPEND implicit_objs "${obj}")
      endif()
    endforeach()
  endif()

  # Cleanup list of library and framework directories.
  set(desc_dirs "library")
  set(desc_fwks "framework")
  foreach(t dirs fwks)
    set(implicit_${t} "")
    foreach(d IN LISTS implicit_${t}_tmp)
      get_filename_component(dir "${d}" ABSOLUTE)
      string(FIND "${dir}" "${CMAKE_FILES_DIRECTORY}/" pos)
      if(NOT pos LESS 0)
        set(msg ", skipping non-system directory")
      else()
        set(msg "")
        list(APPEND implicit_${t} "${dir}")
      endif()
      string(APPEND log "  collapse ${desc_${t}} dir [${d}] ==> [${dir}]${msg}\n")
    endforeach()
    list(REMOVE_DUPLICATES implicit_${t})
  endforeach()

  # Log results.
  string(APPEND log "  implicit libs: [${implicit_libs}]\n")
  string(APPEND log "  implicit objs: [${implicit_objs}]\n")
  string(APPEND log "  implicit dirs: [${implicit_dirs}]\n")
  string(APPEND log "  implicit fwks: [${implicit_fwks}]\n")

  # Return results.
  set(${lib_var} "${implicit_libs}" PARENT_SCOPE)
  set(${dir_var} "${implicit_dirs}" PARENT_SCOPE)
  set(${fwk_var} "${implicit_fwks}" PARENT_SCOPE)
  set(${log_var} "${log}" PARENT_SCOPE)

  if(EXTRA_PARSE_COMPUTE_IMPLICIT_OBJECTS)
    set(${EXTRA_PARSE_COMPUTE_IMPLICIT_OBJECTS} "${implicit_objs}" PARENT_SCOPE)
  endif()
endfunction()

cmake_policy(POP)