cmake: Download Boost if inadequate local version

Building SDL2 from externals is incompatible with Conan's version of
libiconv, a requirement of Conan's Boost package. Solution is to use the
same Boost package in use by the linux-fresh container. This tells CMake
to download boost_1_75_0.tar.xz from yuzu-emu/ext-linux-bin at CMake's
configuration step, much the same way Qt and FFmpeg are downloaded for
Windows.

Also makes DownloadExternals.cmake cross-platform. Although the CMake
code is not entirely specific to Linux, only Linux has Boost libraries
available at ext-linux-bin, whereas there is no equivalent Boost package
for Windows at ext-windows-bin. caveat emptor

1 files changed, 18 insertions, 4 deletions

diff --git a/CMakeModules/DownloadExternals.cmake b/CMakeModules/DownloadExternals.cmake
index d3f91764d..4c4dec5ff 100644
--- a/CMakeModules/DownloadExternals.cmake
+++ b/CMakeModules/DownloadExternals.cmake
@@ -4,15 +4,29 @@
 #   remote_path: path to the file to download, relative to the remote repository root
 #   prefix_var: name of a variable which will be set with the path to the extracted contents
 function(download_bundled_external remote_path lib_name prefix_var)
+
+set(package_repo "no_platform")
+set(package_extension "no_platform")
+if (WIN32)
+    set(package_repo "ext-windows-bin/raw/master/")
+    set(package_extension ".7z")
+elseif (${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
+    set(package_repo "ext-linux-bin/raw/main/")
+    set(package_extension ".tar.xz")
+else()
+    message(FATAL_ERROR "No package available for this platform")
+endif()
+set(package_url "https://github.com/yuzu-emu/${package_repo}")
+
 set(prefix "${CMAKE_BINARY_DIR}/externals/${lib_name}")
 if (NOT EXISTS "${prefix}")
     message(STATUS "Downloading binaries for ${lib_name}...")
     file(DOWNLOAD
-        https://github.com/yuzu-emu/ext-windows-bin/raw/master/${remote_path}${lib_name}.7z
-        "${CMAKE_BINARY_DIR}/externals/${lib_name}.7z" SHOW_PROGRESS)
-    execute_process(COMMAND ${CMAKE_COMMAND} -E tar xf "${CMAKE_BINARY_DIR}/externals/${lib_name}.7z"
+        ${package_url}${remote_path}${lib_name}${package_extension}
+        "${CMAKE_BINARY_DIR}/externals/${lib_name}${package_extension}" SHOW_PROGRESS)
+    execute_process(COMMAND ${CMAKE_COMMAND} -E tar xf "${CMAKE_BINARY_DIR}/externals/${lib_name}${package_extension}"
         WORKING_DIRECTORY "${CMAKE_BINARY_DIR}/externals")
 endif()
 message(STATUS "Using bundled binaries at ${prefix}")
 set(${prefix_var} "${prefix}" PARENT_SCOPE)
-endfunction()
\ No newline at end of file
+endfunction()