This file was created while investigating issue associated with https://discourse.slicer.org/t/vs2019-build-problem-please-help/30863

SlicerCheckCMakeHTTPSDownload.cmake

# SPDX-FileCopyrightText: Copyright 2023 Kitware, Inc. and Contributors
# SPDX-License-Identifier: BSD-3-Clause

# Adapted from https://github.com/Kitware/CMake/blob/v3.27.1/Modules/ExternalProject/download.cmake.in
function(check_file_hash filepath expected_value)

  if("${filepath}" STREQUAL "")
    message(FATAL_ERROR "filepath Can't be empty")
  endif()

  if("${expected_value}" STREQUAL "")
    message(FATAL_ERROR "expected_value Can't be empty")
  endif()

  message(STATUS "Verifying file...
       file='${filepath}'")

  file("SHA512" "${filepath}" actual_value)

  if(NOT "${actual_value}" STREQUAL "${expected_value}")
    message(FATAL_ERROR "SHA512 hash of
    ${filepath}
  does not match expected value
    expected: '${expected_value}'
      actual: '${actual_value}'")
  endif()

  message(STATUS "Verifying file... - ok")

endfunction()


function(slicer_check_cmake_https_download url sha512)
  set(dest "${CMAKE_CURRENT_BINARY_DIR}/slicer_check_cmake_https_download")
  if(EXISTS ${dest})
    set(msg "Removing '${dest}'")
    message(STATUS "${msg}")
    file(REMOVE ${dest})
    message(STATUS "${msg} - ok")
  endif()

  # Download
  set(msg "Checking if CMake https download works for '${url}'")
  message(STATUS "${msg}")
  file(
    DOWNLOAD
      ${url}
      ${dest}
    SHOW_PROGRESS
    STATUS status
    )
  list(GET status 0 error_code)
  if(error_code)
    list(GET status 1 error_msg)
    message(FATAL_ERROR "error: ${error_msg}")
  endif()
  message(STATUS "${msg} - ok")
  
  message(STATUS "")

  # Verify
  check_file_hash(${dest} ${sha512})
  
  # Cleanup
  file(REMOVE ${dest})

endfunction()

slicer_check_cmake_https_download(
  "https://www.python.org/ftp/python/3.9.10/Python-3.9.10.tgz"
  "3dc9e6a470a0922bad4856db02bc82cc4174f7a94e355fd0ed8cf9bbfd82dcf0b09d854aa482fe70ed441919a526d49e74658222279b5a25b4aa4fa171f65e9c"
  )

#slicer_check_cmake_https_download(
#  "https://github.com/Slicer/SlicerBinaryDependencies/releases/download/swig/swigwin-4.0.2.zip"
#  "b8f105f9b9db6acc1f6e3741990915b533cd1bc206eb9645fd6836457fd30789b7229d2e3219d8e35f2390605ade0fbca493ae162ec3b4bc4e428b57155db03d"
#  )

Usage

1. Download the script SlicerCheckCMakeHTTPSDownload.cmake

2. Run using CMake

   cmake -P SlicerCheckCMakeHTTPSDownload.cmake
   

3. Expected output

   -- Checking if CMake https download works for 'https://www.python.org/ftp/python/3.9.10/Python-3.9.10.tgz'
   -- [download 0% complete]
   -- [download 1% complete]
   -- [download 2% complete]
   [...]
   -- [download 98% complete]
   -- [download 99% complete]
   -- [download 100% complete]
   -- Checking if CMake https download works for 'https://www.python.org/ftp/python/3.9.10/Python-3.9.10.tgz' - ok
   -- 
   -- Verifying file...
          file='/tmp/slicer_check_cmake_https_download'
   -- Verifying file... - ok