[vcpkg] Add support for installing from HEAD

1 files changed, 131 insertions, 0 deletions

diff --git a/scripts/cmake/vcpkg_from_github.cmake b/scripts/cmake/vcpkg_from_github.cmake
new file mode 100644
index 000000000..f0f8dba8b
--- /dev/null
+++ b/scripts/cmake/vcpkg_from_github.cmake
@@ -0,0 +1,131 @@
+# Usage:
+#   vcpkg_from_github(
+#     OUT_SOURCE_PATH <OutVar for SOURCE_PATH (SOURCE_PATH)>
+#     REPO <Repository (Microsoft/cpprestsdk)>
+#     REF <stable ref (v2.0.0)>
+#     SHA512 <SHA for REF (45d0d7f8cc350...)>
+#     HEAD_REF <unstable branch (master)>
+#   )
+#
+# Notes:
+#   This will export VCPKG_HEAD_VERSION variable during head builds.
+function(vcpkg_from_github)
+    set(oneValueArgs OUT_SOURCE_PATH REPO REF SHA512 HEAD_REF)
+    set(multipleValuesArgs)
+    cmake_parse_arguments(_vdud "" "${oneValueArgs}" "${multipleValuesArgs}" ${ARGN})
+
+    if(NOT _vdud_OUT_SOURCE_PATH)
+        message(FATAL_ERROR "OUT_SOURCE_PATH must be specified.")
+    endif()
+
+    if((_vdud_REF AND NOT _vdud_SHA512) OR (NOT _vdud_REF AND _vdud_SHA512))
+        message(FATAL_ERROR "SHA512 must be specified if REF is specified.")
+    endif()
+
+    if(NOT _vdud_REPO)
+        message(FATAL_ERROR "The GitHub repository must be specified.")
+    endif()
+
+    if(NOT _vdud_REF AND NOT _vdud_HEAD_REF)
+        message(FATAL_ERROR "At least one of REF and HEAD_REF must be specified.")
+    endif()
+
+    string(REGEX REPLACE ".*/" "" REPO_NAME ${_vdud_REPO})
+    string(REGEX REPLACE "/.*" "" ORG_NAME ${_vdud_REPO})
+
+    macro(set_SOURCE_PATH BASE BASEREF)
+        set(SOURCE_PATH "${BASE}/${REPO_NAME}-${BASEREF}")
+        if(EXISTS ${SOURCE_PATH})
+            set(${_vdud_OUT_SOURCE_PATH} "${SOURCE_PATH}" PARENT_SCOPE)
+        else()
+            # Sometimes GitHub strips a leading 'v' off the REF.
+            string(REGEX REPLACE "^v" "" REF ${BASEREF})
+            set(SOURCE_PATH "${BASE}/${REPO_NAME}-${REF}")
+            if(EXISTS ${SOURCE_PATH})
+                set(${_vdud_OUT_SOURCE_PATH} "${SOURCE_PATH}" PARENT_SCOPE)
+            else()
+                message(FATAL_ERROR "Could not determine source path: '${BASE}/${REPO_NAME}-${BASEREF}' does not exist")
+            endif()
+        endif()
+    endmacro()
+
+    if(VCPKG_USE_HEAD_VERSION AND NOT _vdud_HEAD_REF)
+        message(STATUS "Package does not specify HEAD_REF. Falling back to non-HEAD version.")
+        set(VCPKG_USE_HEAD_VERSION OFF)
+    endif()
+
+    # Handle --no-head scenarios
+    if(NOT VCPKG_USE_HEAD_VERSION)
+        if(NOT _vdud_REF)
+            message(FATAL_ERROR "Package does not specify REF. It must built using --head.")
+        endif()
+
+        vcpkg_download_distfile(ARCHIVE
+            URLS "https://github.com/${ORG_NAME}/${REPO_NAME}/archive/${_vdud_REF}.tar.gz"
+            SHA512 "${_vdud_SHA512}"
+            FILENAME "${ORG_NAME}-${REPO_NAME}-${_vdud_REF}.tar.gz"
+        )
+        vcpkg_extract_source_archive_ex(ARCHIVE "${ARCHIVE}")
+        set_SOURCE_PATH(${CURRENT_BUILDTREES_DIR}/src ${_vdud_REF})
+        return()
+    endif()
+
+    # The following is for --head scenarios
+    set(URL "https://github.com/${ORG_NAME}/${REPO_NAME}/archive/${_vdud_HEAD_REF}.tar.gz")
+    set(downloaded_file_path "${DOWNLOADS}/${ORG_NAME}-${REPO_NAME}-${_vdud_HEAD_REF}.tar.gz")
+
+    if(_VCPKG_NO_DOWNLOADS)
+        if(NOT EXISTS ${downloaded_file_path} OR NOT EXISTS ${downloaded_file_path}.version)
+            message(FATAL_ERROR "Downloads are disabled, but '${downloaded_file_path}' does not exist.")
+        endif()
+        message(STATUS "Using cached ${downloaded_file_path}")
+    else()
+        if(EXISTS ${downloaded_file_path})
+            message(STATUS "Purging cached ${downloaded_file_path} to fetch latest (use --no-downloads to suppress)")
+            file(REMOVE ${downloaded_file_path})
+        endif()
+        if(EXISTS ${downloaded_file_path}.version)
+            file(REMOVE ${downloaded_file_path}.version)
+        endif()
+        if(EXISTS ${CURRENT_BUILDTREES_DIR}/src/head)
+            file(REMOVE_RECURSE ${CURRENT_BUILDTREES_DIR}/src/head)
+        endif()
+
+        # Try to download the file and version information from github.
+        message(STATUS "Downloading ${URL}...")
+        file(DOWNLOAD "https://api.github.com/repos/${ORG_NAME}/${REPO_NAME}/git/refs/heads/${_vdud_HEAD_REF}"
+            ${downloaded_file_path}.version
+            STATUS download_status
+        )
+        list(GET download_status 0 status_code)
+        if (NOT "${status_code}" STREQUAL "0")
+            file(REMOVE ${downloaded_file_path}.version)
+            message(FATAL_ERROR "Downloading version info for ${URL}... Failed. Status: ${download_status}")
+        endif()
+
+        file(DOWNLOAD ${URL} ${downloaded_file_path} STATUS download_status)
+        list(GET download_status 0 status_code)
+        if (NOT "${status_code}" STREQUAL "0")
+            file(REMOVE ${downloaded_file_path})
+            message(FATAL_ERROR "Downloading ${URL}... Failed. Status: ${download_status}")
+        else()
+            message(STATUS "Downloading ${URL}... OK")
+        endif()
+    endif()
+
+    vcpkg_extract_source_archive_ex(
+        ARCHIVE "${downloaded_file_path}"
+        WORKING_DIRECTORY "${CURRENT_BUILDTREES_DIR}/src/head"
+    )
+
+    # Parse the github refs response with regex.
+    # TODO: use some JSON swiss-army-knife utility instead.
+    file(READ "${downloaded_file_path}.version" _contents)
+    string(REGEX MATCH "\"sha\": \"[a-f0-9]+\"" x "${_contents}")
+    string(REGEX REPLACE "\"sha\": \"([a-f0-9]+)\"" "\\1" _version ${x})
+
+    # exports VCPKG_HEAD_VERSION to the caller. This will get picked up by ports.cmake after the build.
+    set(VCPKG_HEAD_VERSION ${_version} PARENT_SCOPE)
+
+    set_SOURCE_PATH(${CURRENT_BUILDTREES_DIR}/src/head ${_vdud_HEAD_REF})
+endfunction()