fdlibm init (#4165)

* fdlibm init

* fix links

* Fix different hashes creation with google host

* Move functions to script

* Fix documentation

* [vcpkg_from_git] Add SHA512 argument, switch to zip to better support Windows.

* [fdlibm] Trigger rebuild

* [vcpkg_from_git] Use FETCH_HEAD reference to support tags

2 files changed, 119 insertions, 0 deletions

diff --git a/scripts/cmake/vcpkg_common_functions.cmake b/scripts/cmake/vcpkg_common_functions.cmake
index 595ebb00e..c8b8fa977 100644
--- a/scripts/cmake/vcpkg_common_functions.cmake
+++ b/scripts/cmake/vcpkg_common_functions.cmake
@@ -27,4 +27,5 @@ include(vcpkg_get_program_files_32_bit)
 include(vcpkg_get_program_files_platform_bitness)
 include(vcpkg_get_windows_sdk)
 include(vcpkg_replace_string)
+include(vcpkg_from_git)
 include(vcpkg_test_cmake)
diff --git a/scripts/cmake/vcpkg_from_git.cmake b/scripts/cmake/vcpkg_from_git.cmake
new file mode 100644
index 000000000..c2965292d
--- /dev/null
+++ b/scripts/cmake/vcpkg_from_git.cmake
@@ -0,0 +1,118 @@
+## # vcpkg_from_git
+##
+## Download and extract a project from git
+##
+## ## Usage:
+## ```cmake
+## vcpkg_from_git(
+##     OUT_SOURCE_PATH <SOURCE_PATH>
+##     URL <https://android.googlesource.com/platform/external/fdlibm>
+##     [REF <59f7335e4d...>]
+##     [PATCHES <patch1.patch> <patch2.patch>...]
+## )
+## ```
+##
+## ## Parameters:
+## ### OUT_SOURCE_PATH
+## Specifies the out-variable that will contain the extracted location.
+##
+## This should be set to `SOURCE_PATH` by convention.
+##
+## ### URL
+## The url of the git repository.
+##
+## ### REF
+## The full commit id of the current latest master.
+##
+## ### PATCHES
+## A list of patches to be applied to the extracted sources.
+##
+## Relative paths are based on the port directory.
+##
+## ## Notes:
+## `REF` and `URL` must be specified.
+##
+## ## Examples:
+##
+## * [fdlibm](https://github.com/Microsoft/vcpkg/blob/master/ports/fdlibm/portfile.cmake)
+
+function(vcpkg_from_git)
+  set(oneValueArgs OUT_SOURCE_PATH URL REF SHA512)
+  set(multipleValuesArgs PATCHES)
+  cmake_parse_arguments(_vdud "" "${oneValueArgs}" "${multipleValuesArgs}" ${ARGN})
+
+  if(NOT DEFINED _vdud_OUT_SOURCE_PATH)
+    message(FATAL_ERROR "OUT_SOURCE_PATH must be specified.")
+  endif()
+
+  if(NOT DEFINED _vdud_URL)
+    message(FATAL_ERROR "The git url must be specified")
+  endif()
+
+  if(NOT DEFINED _vdud_REF)
+    message(FATAL_ERROR "The git ref must be specified.")
+  endif()
+
+  if(NOT DEFINED _vdud_SHA512)
+    message(FATAL_ERROR "vcpkg_from_git requires a SHA512 argument. If you do not know the SHA512, add it as 'SHA512 0' and re-run this command.")
+  endif()
+
+  string(REPLACE "/" "-" SANITIZED_REF "${_vdud_REF}")
+  set(TEMP_ARCHIVE "${DOWNLOADS}/temp/${PORT}-${SANITIZED_REF}.zip")
+  set(ARCHIVE "${DOWNLOADS}/${PORT}-${SANITIZED_REF}.zip")
+  set(TEMP_SOURCE_PATH "${CURRENT_BUILDTREES_DIR}/src/${SANITIZED_REF}")
+
+  function(test_hash FILE_PATH FILE_KIND CUSTOM_ERROR_ADVICE)
+    file(SHA512 ${FILE_PATH} FILE_HASH)
+    if(NOT FILE_HASH STREQUAL _vdud_SHA512)
+        message(FATAL_ERROR
+            "\nFile does not have expected hash:\n"
+            "        File path: [ ${FILE_PATH} ]\n"
+            "    Expected hash: [ ${_vdud_SHA512} ]\n"
+            "      Actual hash: [ ${FILE_HASH} ]\n"
+            "${CUSTOM_ERROR_ADVICE}\n")
+    endif()
+  endfunction()
+
+  if(NOT EXISTS "${ARCHIVE}")
+    if(_VCPKG_NO_DOWNLOADS)
+        message(FATAL_ERROR "Downloads are disabled, but '${ARCHIVE}' does not exist.")
+    endif()
+    message(STATUS "Fetching ${_vdud_URL}...")
+    find_program(GIT NAMES git git.cmd)
+    # Note: git init is safe to run multiple times
+    vcpkg_execute_required_process(
+      COMMAND ${GIT} init git-tmp
+      WORKING_DIRECTORY ${DOWNLOADS}
+      LOGNAME git-init
+    )
+    vcpkg_execute_required_process(
+      COMMAND ${GIT} fetch ${_vdud_URL} ${_vdud_REF} --depth 1 -n
+      WORKING_DIRECTORY ${DOWNLOADS}/git-tmp
+      LOGNAME git-fetch
+    )
+    file(MAKE_DIRECTORY "${DOWNLOADS}/temp")
+    vcpkg_execute_required_process(
+      COMMAND ${GIT} archive FETCH_HEAD -o "${TEMP_ARCHIVE}"
+      WORKING_DIRECTORY ${DOWNLOADS}/git-tmp
+      LOGNAME git-archive
+    )
+    test_hash("${TEMP_ARCHIVE}" "downloaded repo" "")
+    get_filename_component(downloaded_file_dir "${ARCHIVE}" DIRECTORY)
+    file(MAKE_DIRECTORY "${downloaded_file_dir}")
+    file(RENAME "${TEMP_ARCHIVE}" "${ARCHIVE}")
+  else()
+    message(STATUS "Using cached ${ARCHIVE}")
+    test_hash("${ARCHIVE}" "cached file" "Please delete the file and retry if this file should be downloaded again.")
+  endif()
+
+  vcpkg_extract_source_archive_ex(
+    OUT_SOURCE_PATH SOURCE_PATH
+    ARCHIVE "${ARCHIVE}"
+    REF "${SANITIZED_REF}"
+    PATCHES ${_vdud_PATCHES}
+    NO_REMOVE_ONE_LEVEL
+  )
+
+  set(${_vdud_OUT_SOURCE_PATH} "${SOURCE_PATH}" PARENT_SCOPE)
+endfunction()