ExternalProject.cmake

#.rst:
# ExternalProject
# ---------------
#
# Create custom targets to build projects in external trees
#
# The ``ExternalProject_Add`` function creates a custom target to drive
# download, update/patch, configure, build, install and test steps of an
# external project:
#
# .. code-block:: cmake
#
#  ExternalProject_Add(<name>    # Name for custom target
#    [DEPENDS projects...]       # Targets on which the project depends
#    [PREFIX dir]                # Root dir for entire project
#    [LIST_SEPARATOR sep]        # Sep to be replaced by ; in cmd lines
#    [TMP_DIR dir]               # Directory to store temporary files
#    [STAMP_DIR dir]             # Directory to store step timestamps
#   #--Download step--------------
#    [DOWNLOAD_NAME fname]       # File name to store (if not end of URL)
#    [DOWNLOAD_DIR dir]          # Directory to store downloaded files
#    [DOWNLOAD_COMMAND cmd...]   # Command to download source tree
#    [CVS_REPOSITORY cvsroot]    # CVSROOT of CVS repository
#    [CVS_MODULE mod]            # Module to checkout from CVS repo
#    [CVS_TAG tag]               # Tag to checkout from CVS repo
#    [SVN_REPOSITORY url]        # URL of Subversion repo
#    [SVN_REVISION rev]          # Revision to checkout from Subversion repo
#    [SVN_USERNAME john ]        # Username for Subversion checkout and update
#    [SVN_PASSWORD doe ]         # Password for Subversion checkout and update
#    [SVN_TRUST_CERT 1 ]         # Trust the Subversion server site certificate
#    [GIT_REPOSITORY url]        # URL of git repo
#    [GIT_TAG tag]               # Git branch name, commit id or tag
#    [GIT_SUBMODULES modules...] # Git submodules that shall be updated, all if empty
#    [HG_REPOSITORY url]         # URL of mercurial repo
#    [HG_TAG tag]                # Mercurial branch name, commit id or tag
#    [URL /.../src.tgz]          # Full path or URL of source
#    [URL_HASH ALGO=value]       # Hash of file at URL
#    [URL_MD5 md5]               # Equivalent to URL_HASH MD5=md5
#    [TLS_VERIFY bool]           # Should certificate for https be checked
#    [TLS_CAINFO file]           # Path to a certificate authority file
#    [TIMEOUT seconds]           # Time allowed for file download operations
#   #--Update/Patch step----------
#    [UPDATE_COMMAND cmd...]     # Source work-tree update command
#    [PATCH_COMMAND cmd...]      # Command to patch downloaded source
#   #--Configure step-------------
#    [SOURCE_DIR dir]            # Source dir to be used for build
#    [CONFIGURE_COMMAND cmd...]  # Build tree configuration command
#    [CMAKE_COMMAND /.../cmake]  # Specify alternative cmake executable
#    [CMAKE_GENERATOR gen]       # Specify generator for native build
#    [CMAKE_GENERATOR_TOOLSET t] # Generator-specific toolset name
#    [CMAKE_ARGS args...]        # Arguments to CMake command line
#    [CMAKE_CACHE_ARGS args...]  # Initial cache arguments, of the form -Dvar:string=on
#   #--Build step-----------------
#    [BINARY_DIR dir]            # Specify build dir location
#    [BUILD_COMMAND cmd...]      # Command to drive the native build
#    [BUILD_IN_SOURCE 1]         # Use source dir for build dir
#   #--Install step---------------
#    [INSTALL_DIR dir]           # Installation prefix
#    [INSTALL_COMMAND cmd...]    # Command to drive install after build
#   #--Test step------------------
#    [TEST_BEFORE_INSTALL 1]     # Add test step executed before install step
#    [TEST_AFTER_INSTALL 1]      # Add test step executed after install step
#    [TEST_COMMAND cmd...]       # Command to drive test
#   #--Output logging-------------
#    [LOG_DOWNLOAD 1]            # Wrap download in script to log output
#    [LOG_UPDATE 1]              # Wrap update in script to log output
#    [LOG_CONFIGURE 1]           # Wrap configure in script to log output
#    [LOG_BUILD 1]               # Wrap build in script to log output
#    [LOG_TEST 1]                # Wrap test in script to log output
#    [LOG_INSTALL 1]             # Wrap install in script to log output
#   #--Custom targets-------------
#    [STEP_TARGETS st1 st2 ...]  # Generate custom targets for these steps
#    )
#
# The ``*_DIR`` options specify directories for the project, with default
# directories computed as follows.  If the ``PREFIX`` option is given to
# ``ExternalProject_Add()`` or the ``EP_PREFIX`` directory property is set,
# then an external project is built and installed under the specified prefix::
#
#  TMP_DIR      = <prefix>/tmp
#  STAMP_DIR    = <prefix>/src/<name>-stamp
#  DOWNLOAD_DIR = <prefix>/src
#  SOURCE_DIR   = <prefix>/src/<name>
#  BINARY_DIR   = <prefix>/src/<name>-build
#  INSTALL_DIR  = <prefix>
#
# Otherwise, if the ``EP_BASE`` directory property is set then components
# of an external project are stored under the specified base::
#
#  TMP_DIR      = <base>/tmp/<name>
#  STAMP_DIR    = <base>/Stamp/<name>
#  DOWNLOAD_DIR = <base>/Download/<name>
#  SOURCE_DIR   = <base>/Source/<name>
#  BINARY_DIR   = <base>/Build/<name>
#  INSTALL_DIR  = <base>/Install/<name>
#
# If no ``PREFIX``, ``EP_PREFIX``, or ``EP_BASE`` is specified then the
# default is to set ``PREFIX`` to ``<name>-prefix``.  Relative paths are
# interpreted with respect to the build directory corresponding to the
# source directory in which ``ExternalProject_Add`` is invoked.
#
# If ``SOURCE_DIR`` is explicitly set to an existing directory the project
# will be built from it.  Otherwise a download step must be specified
# using one of the ``DOWNLOAD_COMMAND``, ``CVS_*``, ``SVN_*``, or ``URL``
# options.  The ``URL`` option may refer locally to a directory or source
# tarball, or refer to a remote tarball (e.g. ``http://.../src.tgz``).
#
# The ``ExternalProject_Add_Step`` function adds a custom step to an
# external project:
#
# .. code-block:: cmake
#
#  ExternalProject_Add_Step(<name> <step> # Names of project and custom step
#    [COMMAND cmd...]        # Command line invoked by this step
#    [COMMENT "text..."]     # Text printed when step executes
#    [DEPENDEES steps...]    # Steps on which this step depends
#    [DEPENDERS steps...]    # Steps that depend on this step
#    [DEPENDS files...]      # Files on which this step depends
#    [ALWAYS 1]              # No stamp file, step always runs
#    [WORKING_DIRECTORY dir] # Working directory for command
#    [LOG 1]                 # Wrap step in script to log output
#    )
#
# The command line, comment, and working directory of every standard and
# custom step is processed to replace tokens ``<SOURCE_DIR>``,
# ``<BINARY_DIR>``, ``<INSTALL_DIR>``, and ``<TMP_DIR>`` with
# corresponding property values.
#
# Any builtin step that specifies a ``<step>_COMMAND cmd...`` or custom
# step that specifies a ``COMMAND cmd...`` may specify additional command
# lines using the form ``COMMAND cmd...``.  At build time the commands
# will be executed in order and aborted if any one fails.  For example::
#
#  ... BUILD_COMMAND make COMMAND echo done ...
#
# specifies to run ``make`` and then ``echo done`` during the build step.
# Whether the current working directory is preserved between commands is
# not defined.  Behavior of shell operators like ``&&`` is not defined.
#
# The ``ExternalProject_Get_Property`` function retrieves external project
# target properties::
#
#  ExternalProject_Get_Property(<name> [prop1 [prop2 [...]]])
#
# It stores property values in variables of the same name.  Property
# names correspond to the keyword argument names of
# ``ExternalProject_Add``.
#
# The ``ExternalProject_Add_StepTargets`` function generates custom
# targets for the steps listed::
#
#  ExternalProject_Add_StepTargets(<name> [step1 [step2 [...]]])
#
# If ``STEP_TARGETS`` is set then ``ExternalProject_Add_StepTargets`` is
# automatically called at the end of matching calls to
# ``ExternalProject_Add_Step``.  Pass ``STEP_TARGETS`` explicitly to
# individual ``ExternalProject_Add`` calls, or implicitly to all
# ``ExternalProject_Add`` calls by setting the directory property
# ``EP_STEP_TARGETS``.
#
# If ``STEP_TARGETS`` is not set, clients may still manually call
# ``ExternalProject_Add_StepTargets`` after calling
# ``ExternalProject_Add`` or ``ExternalProject_Add_Step``.
#
# This functionality is provided to make it easy to drive the steps
# independently of each other by specifying targets on build command
# lines.  For example, you may be submitting to a sub-project based
# dashboard, where you want to drive the configure portion of the build,
# then submit to the dashboard, followed by the build portion, followed
# by tests.  If you invoke a custom target that depends on a step
# halfway through the step dependency chain, then all the previous steps
# will also run to ensure everything is up to date.
#
# For example, to drive configure, build and test steps independently
# for each ``ExternalProject_Add`` call in your project, write the following
# line prior to any ``ExternalProject_Add`` calls in your ``CMakeLists.txt``
# file::
#
#  set_property(DIRECTORY PROPERTY EP_STEP_TARGETS configure build test)

#=============================================================================
# Copyright 2008-2013 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
#  License text for the above reference.)

# Pre-compute a regex to match documented keywords for each command.
math(EXPR _ep_documentation_line_count "${CMAKE_CURRENT_LIST_LINE} - 16")
file(STRINGS "${CMAKE_CURRENT_LIST_FILE}" lines
     LIMIT_COUNT ${_ep_documentation_line_count}
     REGEX "^#  (  \\[[A-Z0-9_]+ [^]]*\\] +#.*$|[A-Za-z0-9_]+\\()")
foreach(line IN LISTS lines)
  if("${line}" MATCHES "^#  [A-Za-z0-9_]+\\(")
    if(_ep_func)
      set(_ep_keywords_${_ep_func} "${_ep_keywords_${_ep_func}})$")
    endif()
    string(REGEX REPLACE "^#  ([A-Za-z0-9_]+)\\(.*" "\\1" _ep_func "${line}")
    #message("function [${_ep_func}]")
    set(_ep_keywords_${_ep_func} "^(")
    set(_ep_keyword_sep)
  else()
    string(REGEX REPLACE "^#    \\[([A-Z0-9_]+) .*" "\\1" _ep_key "${line}")
    #message("  keyword [${_ep_key}]")
    set(_ep_keywords_${_ep_func}
      "${_ep_keywords_${_ep_func}}${_ep_keyword_sep}${_ep_key}")
    set(_ep_keyword_sep "|")
  endif()
endforeach()
if(_ep_func)
  set(_ep_keywords_${_ep_func} "${_ep_keywords_${_ep_func}})$")
endif()

# Save regex matching supported hash algorithm names.
set(_ep_hash_algos "MD5|SHA1|SHA224|SHA256|SHA384|SHA512")
set(_ep_hash_regex "^(${_ep_hash_algos})=([0-9A-Fa-f]+)$")

function(_ep_parse_arguments f name ns args)
  # Transfer the arguments to this function into target properties for the
  # new custom target we just added so that we can set up all the build steps
  # correctly based on target properties.
  #
  # We loop through ARGN and consider the namespace starting with an
  # upper-case letter followed by at least two more upper-case letters,
  # numbers or underscores to be keywords.
  set(key)

  foreach(arg IN LISTS args)
    set(is_value 1)

    if(arg MATCHES "^[A-Z][A-Z0-9_][A-Z0-9_]+$" AND
        NOT ((arg STREQUAL "${key}") AND (key STREQUAL "COMMAND")) AND
        NOT arg MATCHES "^(TRUE|FALSE)$")
      if(_ep_keywords_${f} AND arg MATCHES "${_ep_keywords_${f}}")
        set(is_value 0)
      endif()
    endif()

    if(is_value)
      if(key)
        # Value
        if(NOT arg STREQUAL "")
          set_property(TARGET ${name} APPEND PROPERTY ${ns}${key} "${arg}")
        else()
          get_property(have_key TARGET ${name} PROPERTY ${ns}${key} SET)
          if(have_key)
            get_property(value TARGET ${name} PROPERTY ${ns}${key})
            set_property(TARGET ${name} PROPERTY ${ns}${key} "${value};${arg}")
          else()
            set_property(TARGET ${name} PROPERTY ${ns}${key} "${arg}")
          endif()
        endif()
      else()
        # Missing Keyword
        message(AUTHOR_WARNING "value '${arg}' with no previous keyword in ${f}")
      endif()
    else()
      set(key "${arg}")
    endif()
  endforeach()
endfunction()


define_property(DIRECTORY PROPERTY "EP_BASE" INHERITED
  BRIEF_DOCS "Base directory for External Project storage."
  FULL_DOCS
  "See documentation of the ExternalProject_Add() function in the "
  "ExternalProject module."
  )

define_property(DIRECTORY PROPERTY "EP_PREFIX" INHERITED
  BRIEF_DOCS "Top prefix for External Project storage."
  FULL_DOCS
  "See documentation of the ExternalProject_Add() function in the "
  "ExternalProject module."
  )

define_property(DIRECTORY PROPERTY "EP_STEP_TARGETS" INHERITED
  BRIEF_DOCS
  "List of ExternalProject steps that automatically get corresponding targets"
  FULL_DOCS
  "See documentation of the ExternalProject_Add_StepTargets() function in the "
  "ExternalProject module."
  )


function(_ep_write_gitclone_script script_filename source_dir git_EXECUTABLE git_repository git_tag git_submodules src_name work_dir gitclone_infofile gitclone_stampfile)
  file(WRITE ${script_filename}
"if(\"${git_tag}\" STREQUAL \"\")
  message(FATAL_ERROR \"Tag for git checkout should not be empty.\")
endif()

set(run 0)

if(\"${gitclone_infofile}\" IS_NEWER_THAN \"${gitclone_stampfile}\")
  set(run 1)
endif()

if(NOT run)
  message(STATUS \"Avoiding repeated git clone, stamp file is up to date: '${gitclone_stampfile}'\")
  return()
endif()

execute_process(
  COMMAND \${CMAKE_COMMAND} -E remove_directory \"${source_dir}\"
  RESULT_VARIABLE error_code
  )
if(error_code)
  message(FATAL_ERROR \"Failed to remove directory: '${source_dir}'\")
endif()

# try the clone 3 times incase there is an odd git clone issue
set(error_code 1)
set(number_of_tries 0)
while(error_code AND number_of_tries LESS 3)
  execute_process(
    COMMAND \"${git_EXECUTABLE}\" clone \"${git_repository}\" \"${src_name}\"
    WORKING_DIRECTORY \"${work_dir}\"
    RESULT_VARIABLE error_code
    )
  math(EXPR number_of_tries \"\${number_of_tries} + 1\")
endwhile()
if(number_of_tries GREATER 1)
  message(STATUS \"Had to git clone more than once:
          \${number_of_tries} times.\")
endif()
if(error_code)
  message(FATAL_ERROR \"Failed to clone repository: '${git_repository}'\")
endif()

execute_process(
  COMMAND \"${git_EXECUTABLE}\" checkout ${git_tag}
  WORKING_DIRECTORY \"${work_dir}/${src_name}\"
  RESULT_VARIABLE error_code
  )
if(error_code)
  message(FATAL_ERROR \"Failed to checkout tag: '${git_tag}'\")
endif()

execute_process(
  COMMAND \"${git_EXECUTABLE}\" submodule init
  WORKING_DIRECTORY \"${work_dir}/${src_name}\"
  RESULT_VARIABLE error_code
  )
if(error_code)
  message(FATAL_ERROR \"Failed to init submodules in: '${work_dir}/${src_name}'\")
endif()

execute_process(
  COMMAND \"${git_EXECUTABLE}\" submodule update --recursive ${git_submodules}
  WORKING_DIRECTORY \"${work_dir}/${src_name}\"
  RESULT_VARIABLE error_code
  )
if(error_code)
  message(FATAL_ERROR \"Failed to update submodules in: '${work_dir}/${src_name}'\")
endif()

# Complete success, update the script-last-run stamp file:
#
execute_process(
  COMMAND \${CMAKE_COMMAND} -E copy
    \"${gitclone_infofile}\"
    \"${gitclone_stampfile}\"
  WORKING_DIRECTORY \"${work_dir}/${src_name}\"
  RESULT_VARIABLE error_code
  )
if(error_code)
  message(FATAL_ERROR \"Failed to copy script-last-run stamp file: '${gitclone_stampfile}'\")
endif()

"
)

endfunction()

function(_ep_write_hgclone_script script_filename source_dir hg_EXECUTABLE hg_repository hg_tag src_name work_dir hgclone_infofile hgclone_stampfile)
  file(WRITE ${script_filename}
"if(\"${hg_tag}\" STREQUAL \"\")
  message(FATAL_ERROR \"Tag for hg checkout should not be empty.\")
endif()

set(run 0)

if(\"${hgclone_infofile}\" IS_NEWER_THAN \"${hgclone_stampfile}\")
  set(run 1)
endif()

if(NOT run)
  message(STATUS \"Avoiding repeated hg clone, stamp file is up to date: '${hgclone_stampfile}'\")
  return()
endif()

execute_process(
  COMMAND \${CMAKE_COMMAND} -E remove_directory \"${source_dir}\"
  RESULT_VARIABLE error_code
  )
if(error_code)
  message(FATAL_ERROR \"Failed to remove directory: '${source_dir}'\")
endif()

execute_process(
  COMMAND \"${hg_EXECUTABLE}\" clone \"${hg_repository}\" \"${src_name}\"
  WORKING_DIRECTORY \"${work_dir}\"
  RESULT_VARIABLE error_code
  )
if(error_code)
  message(FATAL_ERROR \"Failed to clone repository: '${hg_repository}'\")
endif()

execute_process(
  COMMAND \"${hg_EXECUTABLE}\" update ${hg_tag}
  WORKING_DIRECTORY \"${work_dir}/${src_name}\"
  RESULT_VARIABLE error_code
  )
if(error_code)
  message(FATAL_ERROR \"Failed to checkout tag: '${hg_tag}'\")
endif()

# Complete success, update the script-last-run stamp file:
#
execute_process(
  COMMAND \${CMAKE_COMMAND} -E copy
    \"${hgclone_infofile}\"
    \"${hgclone_stampfile}\"
  WORKING_DIRECTORY \"${work_dir}/${src_name}\"
  RESULT_VARIABLE error_code
  )
if(error_code)
  message(FATAL_ERROR \"Failed to copy script-last-run stamp file: '${hgclone_stampfile}'\")
endif()

"
)

endfunction()


function(_ep_write_gitupdate_script script_filename git_EXECUTABLE git_tag git_submodules git_repository work_dir)
  file(WRITE ${script_filename}
"if(\"${git_tag}\" STREQUAL \"\")
  message(FATAL_ERROR \"Tag for git checkout should not be empty.\")
endif()

execute_process(
  COMMAND \"${git_EXECUTABLE}\" rev-list --max-count=1 HEAD
  WORKING_DIRECTORY \"${work_dir}\"
  RESULT_VARIABLE error_code
  OUTPUT_VARIABLE head_sha
  )
if(error_code)
  message(FATAL_ERROR \"Failed to get the hash for HEAD\")
endif()

execute_process(
  COMMAND \"${git_EXECUTABLE}\" show-ref ${git_tag}
  WORKING_DIRECTORY \"${work_dir}\"
  OUTPUT_VARIABLE show_ref_output
  )
# If a remote ref is asked for, which can possibly move around,
# we must always do a fetch and checkout.
if(\"\${show_ref_output}\" MATCHES \"remotes\")
  set(is_remote_ref 1)
else()
  set(is_remote_ref 0)
endif()

# This will fail if the tag does not exist (it probably has not been fetched
# yet).
execute_process(
  COMMAND \"${git_EXECUTABLE}\" rev-list --max-count=1 ${git_tag}
  WORKING_DIRECTORY \"${work_dir}\"
  RESULT_VARIABLE error_code
  OUTPUT_VARIABLE tag_sha
  )

# Is the hash checkout out that we want?
if(error_code OR is_remote_ref OR NOT (\"\${tag_sha}\" STREQUAL \"\${head_sha}\"))
  execute_process(
    COMMAND \"${git_EXECUTABLE}\" fetch
    WORKING_DIRECTORY \"${work_dir}\"
    RESULT_VARIABLE error_code
    )
  if(error_code)
    message(FATAL_ERROR \"Failed to fetch repository '${git_repository}'\")
  endif()

  execute_process(
    COMMAND \"${git_EXECUTABLE}\" checkout ${git_tag}
    WORKING_DIRECTORY \"${work_dir}\"
    RESULT_VARIABLE error_code
    )
  if(error_code)
    message(FATAL_ERROR \"Failed to checkout tag: '${git_tag}'\")
  endif()

  execute_process(
    COMMAND \"${git_EXECUTABLE}\" submodule update --recursive ${git_submodules}
    WORKING_DIRECTORY \"${work_dir}/${src_name}\"
    RESULT_VARIABLE error_code
    )
  if(error_code)
    message(FATAL_ERROR \"Failed to update submodules in: '${work_dir}/${src_name}'\")
  endif()
endif()

"
)

endfunction(_ep_write_gitupdate_script)

function(_ep_write_downloadfile_script script_filename remote local timeout hash tls_verify tls_cainfo)
  if(timeout)
    set(timeout_args TIMEOUT ${timeout})
    set(timeout_msg "${timeout} seconds")
  else()
    set(timeout_args "# no TIMEOUT")
    set(timeout_msg "none")
  endif()

  if("${hash}" MATCHES "${_ep_hash_regex}")
    set(hash_args EXPECTED_HASH ${CMAKE_MATCH_1}=${CMAKE_MATCH_2})
  else()
    set(hash_args "# no EXPECTED_HASH")
  endif()
  # check for curl globals in the project
  if(DEFINED CMAKE_TLS_VERIFY)
    set(tls_verify "set(CMAKE_TLS_VERIFY ${CMAKE_TLS_VERIFY})")
  endif()
  if(DEFINED CMAKE_TLS_CAINFO)
    set(tls_cainfo "set(CMAKE_TLS_CAINFO \"${CMAKE_TLS_CAINFO}\")")
  endif()

  # now check for curl locals so that the local values
  # will override the globals

  # check for tls_verify argument
  string(LENGTH "${tls_verify}" tls_verify_len)
  if(tls_verify_len GREATER 0)
    set(tls_verify "set(CMAKE_TLS_VERIFY ${tls_verify})")
  endif()
  # check for tls_cainfo argument
  string(LENGTH "${tls_cainfo}" tls_cainfo_len)
  if(tls_cainfo_len GREATER 0)
    set(tls_cainfo "set(CMAKE_TLS_CAINFO \"${tls_cainfo}\")")
  endif()

  file(WRITE ${script_filename}
"message(STATUS \"downloading...
     src='${remote}'
     dst='${local}'
     timeout='${timeout_msg}'\")

${tls_verify}
${tls_cainfo}

file(DOWNLOAD
  \"${remote}\"
  \"${local}\"
  SHOW_PROGRESS
  ${hash_args}
  ${timeout_args}
  STATUS status
  LOG log)

list(GET status 0 status_code)
list(GET status 1 status_string)

if(NOT status_code EQUAL 0)
  message(FATAL_ERROR \"error: downloading '${remote}' failed
  status_code: \${status_code}
  status_string: \${status_string}
  log: \${log}
\")
endif()

message(STATUS \"downloading... done\")
"
)

endfunction()


function(_ep_write_verifyfile_script script_filename local hash retries download_script)
  if("${hash}" MATCHES "${_ep_hash_regex}")
    set(algo "${CMAKE_MATCH_1}")
    string(TOLOWER "${CMAKE_MATCH_2}" expect_value)
    set(script_content "set(expect_value \"${expect_value}\")
set(attempt 0)
set(succeeded 0)
while(\${attempt} LESS ${retries} OR \${attempt} EQUAL ${retries} AND NOT \${succeeded})
  file(${algo} \"\${file}\" actual_value)
  if(\"\${actual_value}\" STREQUAL \"\${expect_value}\")
    set(succeeded 1)
  elseif(\${attempt} LESS ${retries})
    message(STATUS \"${algo} hash of \${file}
does not match expected value
  expected: \${expect_value}
    actual: \${actual_value}
Retrying download.
\")
    file(REMOVE \"\${file}\")
    execute_process(COMMAND \${CMAKE_COMMAND} -P \"${download_script}\")
  endif()
endwhile()

if(\${succeeded})
  message(STATUS \"verifying file... done\")
else()
  message(FATAL_ERROR \"error: ${algo} hash of
  \${file}
does not match expected value
  expected: \${expect_value}
    actual: \${actual_value}
\")
endif()")
  else()
    set(script_content "message(STATUS \"verifying file... warning: did not verify file - no URL_HASH specified?\")")
  endif()
  file(WRITE ${script_filename} "set(file \"${local}\")
message(STATUS \"verifying file...
     file='\${file}'\")
${script_content}
")
endfunction()


function(_ep_write_extractfile_script script_filename name filename directory)
  set(args "")

  if(filename MATCHES "(\\.|=)(bz2|tar\\.gz|tgz|zip)$")
    set(args xfz)
  endif()

  if(filename MATCHES "(\\.|=)tar$")
    set(args xf)
  endif()

  if(args STREQUAL "")
    message(SEND_ERROR "error: do not know how to extract '${filename}' -- known types are .bz2, .tar, .tar.gz, .tgz and .zip")
    return()
  endif()

  file(WRITE ${script_filename}
"# Make file names absolute:
#
get_filename_component(filename \"${filename}\" ABSOLUTE)
get_filename_component(directory \"${directory}\" ABSOLUTE)

message(STATUS \"extracting...
     src='\${filename}'
     dst='\${directory}'\")

if(NOT EXISTS \"\${filename}\")
  message(FATAL_ERROR \"error: file to extract does not exist: '\${filename}'\")
endif()

# Prepare a space for extracting:
#
set(i 1234)
while(EXISTS \"\${directory}/../ex-${name}\${i}\")
  math(EXPR i \"\${i} + 1\")
endwhile()
set(ut_dir \"\${directory}/../ex-${name}\${i}\")
file(MAKE_DIRECTORY \"\${ut_dir}\")

# Extract it:
#
message(STATUS \"extracting... [tar ${args}]\")
execute_process(COMMAND \${CMAKE_COMMAND} -E tar ${args} \${filename}
  WORKING_DIRECTORY \${ut_dir}
  RESULT_VARIABLE rv)

if(NOT rv EQUAL 0)
  message(STATUS \"extracting... [error clean up]\")
  file(REMOVE_RECURSE \"\${ut_dir}\")
  message(FATAL_ERROR \"error: extract of '\${filename}' failed\")
endif()

# Analyze what came out of the tar file:
#
message(STATUS \"extracting... [analysis]\")
file(GLOB contents \"\${ut_dir}/*\")
list(LENGTH contents n)
if(NOT n EQUAL 1 OR NOT IS_DIRECTORY \"\${contents}\")
  set(contents \"\${ut_dir}\")
endif()

# Move \"the one\" directory to the final directory:
#
message(STATUS \"extracting... [rename]\")
file(REMOVE_RECURSE \${directory})
get_filename_component(contents \${contents} ABSOLUTE)
file(RENAME \${contents} \${directory})

# Clean up:
#
message(STATUS \"extracting... [clean up]\")
file(REMOVE_RECURSE \"\${ut_dir}\")

message(STATUS \"extracting... done\")
"
)

endfunction()


function(_ep_set_directories name)
  get_property(prefix TARGET ${name} PROPERTY _EP_PREFIX)
  if(NOT prefix)
    get_property(prefix DIRECTORY PROPERTY EP_PREFIX)
    if(NOT prefix)
      get_property(base DIRECTORY PROPERTY EP_BASE)
      if(NOT base)
        set(prefix "${name}-prefix")
      endif()
    endif()
  endif()
  if(prefix)
    set(tmp_default "${prefix}/tmp")
    set(download_default "${prefix}/src")
    set(source_default "${prefix}/src/${name}")
    set(binary_default "${prefix}/src/${name}-build")
    set(stamp_default "${prefix}/src/${name}-stamp")
    set(install_default "${prefix}")
  else()
    set(tmp_default "${base}/tmp/${name}")
    set(download_default "${base}/Download/${name}")
    set(source_default "${base}/Source/${name}")
    set(binary_default "${base}/Build/${name}")
    set(stamp_default "${base}/Stamp/${name}")
    set(install_default "${base}/Install/${name}")
  endif()
  get_property(build_in_source TARGET ${name} PROPERTY _EP_BUILD_IN_SOURCE)
  if(build_in_source)
    get_property(have_binary_dir TARGET ${name} PROPERTY _EP_BINARY_DIR SET)
    if(have_binary_dir)
      message(FATAL_ERROR
        "External project ${name} has both BINARY_DIR and BUILD_IN_SOURCE!")
    endif()
  endif()
  set(top "${CMAKE_CURRENT_BINARY_DIR}")
  set(places stamp download source binary install tmp)
  foreach(var ${places})
    string(TOUPPER "${var}" VAR)
    get_property(${var}_dir TARGET ${name} PROPERTY _EP_${VAR}_DIR)
    if(NOT ${var}_dir)
      set(${var}_dir "${${var}_default}")
    endif()
    if(NOT IS_ABSOLUTE "${${var}_dir}")
      get_filename_component(${var}_dir "${top}/${${var}_dir}" ABSOLUTE)
    endif()
    set_property(TARGET ${name} PROPERTY _EP_${VAR}_DIR "${${var}_dir}")
  endforeach()
  if(build_in_source)
    get_property(source_dir TARGET ${name} PROPERTY _EP_SOURCE_DIR)
    set_property(TARGET ${name} PROPERTY _EP_BINARY_DIR "${source_dir}")
  endif()

  # Make the directories at CMake configure time *and* add a custom command
  # to make them at build time. They need to exist at makefile generation
  # time for Borland make and wmake so that CMake may generate makefiles
  # with "cd C:\short\paths\with\no\spaces" commands in them.
  #
  # Additionally, the add_custom_command is still used in case somebody
  # removes one of the necessary directories and tries to rebuild without
  # re-running cmake.
  foreach(var ${places})
    string(TOUPPER "${var}" VAR)
    get_property(dir TARGET ${name} PROPERTY _EP_${VAR}_DIR)
    file(MAKE_DIRECTORY "${dir}")
    if(NOT EXISTS "${dir}")
      message(FATAL_ERROR "dir '${dir}' does not exist after file(MAKE_DIRECTORY)")
    endif()
  endforeach()
endfunction()


# IMPORTANT: this MUST be a macro and not a function because of the
# in-place replacements that occur in each ${var}
#
macro(_ep_replace_location_tags target_name)
  set(vars ${ARGN})
  foreach(var ${vars})
    if(${var})
      foreach(dir SOURCE_DIR BINARY_DIR INSTALL_DIR TMP_DIR)
        get_property(val TARGET ${target_name} PROPERTY _EP_${dir})
        string(REPLACE "<${dir}>" "${val}" ${var} "${${var}}")
      endforeach()
    endif()
  endforeach()
endmacro()


function(_ep_write_initial_cache target_name script_filename args)
  # Write out values into an initial cache, that will be passed to CMake with -C
  set(script_initial_cache "")
  set(regex "^([^:]+):([^=]+)=(.*)$")
  set(setArg "")
  foreach(line ${args})
    if("${line}" MATCHES "^-D")
      if(setArg)
        # This is required to build up lists in variables, or complete an entry
        set(setArg "${setArg}${accumulator}\" CACHE ${type} \"Initial cache\" FORCE)")
        set(script_initial_cache "${script_initial_cache}\n${setArg}")
        set(accumulator "")
        set(setArg "")
      endif()
      string(REGEX REPLACE "^-D" "" line ${line})
      if("${line}" MATCHES "${regex}")
        string(REGEX MATCH "${regex}" match "${line}")
        set(name "${CMAKE_MATCH_1}")
        set(type "${CMAKE_MATCH_2}")
        set(value "${CMAKE_MATCH_3}")
        set(setArg "set(${name} \"${value}")
      else()
        message(WARNING "Line '${line}' does not match regex. Ignoring.")
      endif()
    else()
      # Assume this is a list to append to the last var
      set(accumulator "${accumulator};${line}")
    endif()
  endforeach()
  # Catch the final line of the args
  if(setArg)
    set(setArg "${setArg}${accumulator}\" CACHE ${type} \"Initial cache\" FORCE)")
    set(script_initial_cache "${script_initial_cache}\n${setArg}")
  endif()
  # Replace location tags.
  _ep_replace_location_tags(${target_name} script_initial_cache)
  # Write out the initial cache file to the location specified.
  if(NOT EXISTS "${script_filename}.in")
    file(WRITE "${script_filename}.in" "\@script_initial_cache\@\n")
  endif()
  configure_file("${script_filename}.in" "${script_filename}")
endfunction()


function(ExternalProject_Get_Property name)
  foreach(var ${ARGN})
    string(TOUPPER "${var}" VAR)
    get_property(${var} TARGET ${name} PROPERTY _EP_${VAR})
    if(NOT ${var})
      message(FATAL_ERROR "External project \"${name}\" has no ${var}")
    endif()
    set(${var} "${${var}}" PARENT_SCOPE)
  endforeach()
endfunction()


function(_ep_get_configure_command_id name cfg_cmd_id_var)
  get_target_property(cmd ${name} _EP_CONFIGURE_COMMAND)

  if(cmd STREQUAL "")
    # Explicit empty string means no configure step for this project
    set(${cfg_cmd_id_var} "none" PARENT_SCOPE)
  else()
    if(NOT cmd)
      # Default is "use cmake":
      set(${cfg_cmd_id_var} "cmake" PARENT_SCOPE)
    else()
      # Otherwise we have to analyze the value:
      if(cmd MATCHES "^[^;]*/configure")
        set(${cfg_cmd_id_var} "configure" PARENT_SCOPE)
      elseif(cmd MATCHES "^[^;]*/cmake" AND NOT cmd MATCHES ";-[PE];")
        set(${cfg_cmd_id_var} "cmake" PARENT_SCOPE)
      elseif(cmd MATCHES "config")
        set(${cfg_cmd_id_var} "configure" PARENT_SCOPE)
      else()
        set(${cfg_cmd_id_var} "unknown:${cmd}" PARENT_SCOPE)
      endif()
    endif()
  endif()
endfunction()


function(_ep_get_build_command name step cmd_var)
  set(cmd "${${cmd_var}}")
  if(NOT cmd)
    set(args)
    _ep_get_configure_command_id(${name} cfg_cmd_id)
    if(cfg_cmd_id STREQUAL "cmake")
      # CMake project.  Select build command based on generator.
      get_target_property(cmake_generator ${name} _EP_CMAKE_GENERATOR)
      if("${CMAKE_GENERATOR}" MATCHES "Make" AND
         ("${cmake_generator}" MATCHES "Make" OR NOT cmake_generator))
        # The project uses the same Makefile generator.  Use recursive make.
        set(cmd "$(MAKE)")
        if(step STREQUAL "INSTALL")
          set(args install)
        endif()
        if(step STREQUAL "TEST")
          set(args test)
        endif()
      else()
        # Drive the project with "cmake --build".
        get_target_property(cmake_command ${name} _EP_CMAKE_COMMAND)
        if(cmake_command)
          set(cmd "${cmake_command}")
        else()
          set(cmd "${CMAKE_COMMAND}")
        endif()
        set(args --build ${binary_dir} --config ${CMAKE_CFG_INTDIR})
        if(step STREQUAL "INSTALL")
          list(APPEND args --target install)
        endif()
        # But for "TEST" drive the project with corresponding "ctest".
        if(step STREQUAL "TEST")
          string(REGEX REPLACE "^(.*/)cmake([^/]*)$" "\\1ctest\\2" cmd "${cmd}")
          set(args "")
        endif()
      endif()
    else()
      # Non-CMake project.  Guess "make" and "make install" and "make test".
      if("${CMAKE_GENERATOR}" MATCHES "Makefiles")
        # Try to get the parallel arguments
        set(cmd "$(MAKE)")
      else()
        set(cmd "make")
      endif()
      if(step STREQUAL "INSTALL")
        set(args install)
      endif()
      if(step STREQUAL "TEST")
        set(args test)
      endif()
    endif()

    # Use user-specified arguments instead of default arguments, if any.
    get_property(have_args TARGET ${name} PROPERTY _EP_${step}_ARGS SET)
    if(have_args)
      get_target_property(args ${name} _EP_${step}_ARGS)
    endif()

    list(APPEND cmd ${args})
  endif()

  set(${cmd_var} "${cmd}" PARENT_SCOPE)
endfunction()

function(_ep_write_log_script name step cmd_var)
  ExternalProject_Get_Property(${name} stamp_dir)
  set(command "${${cmd_var}}")

  set(make "")
  set(code_cygpath_make "")
  if("${command}" MATCHES "^\\$\\(MAKE\\)")
    # GNU make recognizes the string "$(MAKE)" as recursive make, so
    # ensure that it appears directly in the makefile.
    string(REGEX REPLACE "^\\$\\(MAKE\\)" "\${make}" command "${command}")
    set(make "-Dmake=$(MAKE)")

    if(WIN32 AND NOT CYGWIN)
      set(code_cygpath_make "
if(\${make} MATCHES \"^/\")
  execute_process(
    COMMAND cygpath -w \${make}
    OUTPUT_VARIABLE cygpath_make
    ERROR_VARIABLE cygpath_make
    RESULT_VARIABLE cygpath_error
    OUTPUT_STRIP_TRAILING_WHITESPACE
  )
  if(NOT cygpath_error)
    set(make \${cygpath_make})
  endif()
endif()
")
    endif()
  endif()

  set(config "")
  if("${CMAKE_CFG_INTDIR}" MATCHES "^\\$")
    string(REPLACE "${CMAKE_CFG_INTDIR}" "\${config}" command "${command}")
    set(config "-Dconfig=${CMAKE_CFG_INTDIR}")
  endif()

  # Wrap multiple 'COMMAND' lines up into a second-level wrapper
  # script so all output can be sent to one log file.
  if("${command}" MATCHES ";COMMAND;")
    set(code_execute_process "
${code_cygpath_make}
execute_process(COMMAND \${command} RESULT_VARIABLE result)
if(result)
  set(msg \"Command failed (\${result}):\\n\")
  foreach(arg IN LISTS command)
    set(msg \"\${msg} '\${arg}'\")
  endforeach()
  message(FATAL_ERROR \"\${msg}\")
endif()
")
    set(code "")
    set(cmd "")
    set(sep "")
    foreach(arg IN LISTS command)
      if("x${arg}" STREQUAL "xCOMMAND")