CMake: Support using bundled libraries even if system libraries exist

3 files changed, 102 insertions, 179 deletions

diff --git a/CMake/CheckVendoringApproved.cmake b/CMake/CheckVendoringApproved.cmake
deleted file mode 100644
index 84e2120113..0000000000
--- a/CMake/CheckVendoringApproved.cmake
+++ /dev/null
@@ -1,29 +0,0 @@
-# When packaging Dolphin for an OS distribution, distro vendors usually prefer
-# to limit vendored ("Externals") dependencies as much as possible, in favor of
-# using system provided libraries. This modules provides an option to allow
-# only specific vendored dependencies and error-out at configuration time for
-# non-approved ones.
-#
-# Usage:
-#  $ cmake -D APPROVED_VENDORED_DEPENDENCIES="a;b;c;..."
-#
-# Unless the option is explicitly used, vendored dependencies control is
-# disabled.
-#
-# If you want to disallow all vendored dependencies, put "none" in the approved
-# dependencies list.
-
-set(APPROVED_VENDORED_DEPENDENCIES "" CACHE STRING "\
-Semicolon separated list of approved vendored dependencies. See docstring in \
-CMake/CheckVendoringApproved.cmake.")
-
-function(check_vendoring_approved dep)
-  if(APPROVED_VENDORED_DEPENDENCIES)
-    if(NOT dep IN_LIST APPROVED_VENDORED_DEPENDENCIES)
-      message(SEND_ERROR "\
-Library ${dep} was not found systemwide and was not approved for vendoring. \
-Vendored dependencies control is enabled. Add \"${dep}\" to the \
-APPROVED_VENDORED_DEPENDENCIES list to bypass this error.")
-    endif()
-  endif()
-endfunction()
diff --git a/CMake/DolphinLibraryTools.cmake b/CMake/DolphinLibraryTools.cmake
index f1681306cb..37f439de54 100644
--- a/CMake/DolphinLibraryTools.cmake
+++ b/CMake/DolphinLibraryTools.cmake
@@ -18,3 +18,78 @@ function(dolphin_make_imported_target_if_missing target lib)
     add_library(${target} ALIAS _${lib})
   endif()
 endfunction()
+
+function(dolphin_optional_system_library library)
+  string(TOUPPER ${library} upperlib)
+  set(USE_SYSTEM_${upperlib} "" CACHE STRING "Use system ${library} instead of bundled.  ON - Always use system and fail if unavailable, OFF - Always use bundled, AUTO - Use system if available, otherwise use bundled, blank - Delegate to USE_SYSTEM_LIBS.  Default is blank.")
+  if("${USE_SYSTEM_${upperlib}}" STREQUAL "")
+    if(APPROVED_VENDORED_DEPENDENCIES)
+      string(TOLOWER ${library} lowerlib)
+      if(lowerlib IN_LIST APPROVED_VENDORED_DEPENDENCIES)
+        set(RESOLVED_USE_SYSTEM_${upperlib} AUTO PARENT_SCOPE)
+      else()
+        set(RESOLVED_USE_SYSTEM_${upperlib} ON PARENT_SCOPE)
+      endif()
+    else()
+      set(RESOLVED_USE_SYSTEM_${upperlib} ${USE_SYSTEM_LIBS} PARENT_SCOPE)
+    endif()
+  else()
+    set(RESOLVED_USE_SYSTEM_${upperlib} ${USE_SYSTEM_${upperlib}} PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(dolphin_add_bundled_library library bundled_path)
+  string(TOUPPER ${library} upperlib)
+  if (${RESOLVED_USE_SYSTEM_${upperlib}} STREQUAL "AUTO")
+    message(STATUS "No system ${library} was found.  Using static ${library} from Externals.")
+  else()
+    message(STATUS "Using static ${library} from Externals")
+  endif()
+  if (NOT EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${bundled_path}/CMakeLists.txt")
+    message(FATAL_ERROR "No bundled ${library} was found.  Did you forget to checkout submodules?")
+  endif()
+  add_subdirectory(${bundled_path} EXCLUDE_FROM_ALL)
+endfunction()
+
+function(dolphin_find_optional_system_library library bundled_path)
+  dolphin_optional_system_library(${library})
+  string(TOUPPER ${library} upperlib)
+  if(RESOLVED_USE_SYSTEM_${upperlib})
+    find_package(${library} ${ARGN})
+    # Yay for cmake packages being inconsistent
+    if(DEFINED ${library}_FOUND)
+      set(prefix ${library})
+    else()
+      set(prefix ${upperlib})
+    endif()
+    if((NOT ${found}) AND (NOT ${RESOLVED_USE_SYSTEM_${upperlib}} STREQUAL "AUTO"))
+      message(FATAL_ERROR "No system ${library} was found.  Please install it or set USE_SYSTEM_${upperlib} to AUTO or OFF.")
+    endif()
+  endif()
+  if(${prefix}_FOUND)
+    message(STATUS "Using system ${library}")
+    set(${prefix}_TYPE "System" PARENT_SCOPE)
+  else()
+    dolphin_add_bundled_library(${library} ${bundled_path})
+    set(${prefix}_TYPE "Bundled" PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(dolphin_find_optional_system_library_pkgconfig library search alias bundled_path)
+  dolphin_optional_system_library(${library})
+  string(TOUPPER ${library} upperlib)
+  if(RESOLVED_USE_SYSTEM_${upperlib})
+    pkg_check_modules(${library} ${search} ${ARGN} IMPORTED_TARGET)
+    if((NOT ${library}_FOUND) AND (NOT ${RESOLVED_USE_SYSTEM_${upperlib}} STREQUAL "AUTO"))
+      message(FATAL_ERROR "No system ${library} was found.  Please install it or set USE_SYSTEM_${upperlib} to AUTO or OFF.")
+    endif()
+  endif()
+  if(${library}_FOUND)
+    message(STATUS "Using system ${library}")
+    dolphin_alias_library(${alias} PkgConfig::${library})
+    set(${library}_TYPE "System" PARENT_SCOPE)
+  else()
+    dolphin_add_bundled_library(${library} ${bundled_path})
+    set(${library}_TYPE "Bundled" PARENT_SCOPE)
+  endif()
+endfunction()
diff --git a/CMakeLists.txt b/CMakeLists.txt
index f973dc7ae2..cc3578048d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -85,6 +85,11 @@ if(NOT ANDROID)
   option(ENABLE_CLI_TOOL "Enable dolphin-tool, a CLI-based utility for functions such as managing disc images" ON)
 endif()
 
+
+set(USE_SYSTEM_LIBS "AUTO" CACHE STRING "Use system libraries instead of bundled libraries.  ON - Always use system and fail if unavailable, OFF - Always use bundled, AUTO - Use system if available, otherwise use bundled.  Default is AUTO")
+if(APPROVED_VENDORED_DEPENDENCIES)
+  message(WARNING "APPROVED_VENDORED_DEPENDENCIES is deprecated.  Please migrate to setting USE_SYSTEM_LIBS to ON and setting USE_SYSTEM_<dependency> to either AUTO or OFF to allow bundled libs.")
+endif()
 option(USE_UPNP "Enables UPnP port mapping support" ON)
 option(ENABLE_NOGUI "Enable NoGUI frontend" ON)
 option(ENABLE_QT "Enable Qt (Default)" ON)
@@ -157,7 +162,6 @@ list(APPEND CMAKE_MODULE_PATH
 # Support functions
 include(CheckAndAddFlag)
 include(CheckCCompilerFlag)
-include(CheckVendoringApproved)
 include(DolphinCompileDefinitions)
 include(DolphinDisableWarningsMSVC)
 include(DolphinLibraryTools)
@@ -638,14 +642,7 @@ if(UNIX)
 endif()
 
 if(ENABLE_SDL)
-  find_package(SDL2)
-
-  if(SDL2_FOUND)
-    message(STATUS "Using system SDL2")
-  else()
-    message(STATUS "Using static SDL2 from Externals")
-    add_subdirectory(Externals/SDL)
-  endif()
+  dolphin_find_optional_system_library(SDL2 Externals/SDL)
 endif()
 
 if(ENABLE_ANALYTICS)
@@ -686,14 +683,8 @@ if (_M_X86)
 endif()
 add_subdirectory(Externals/cpp-optparse)
 
-find_package(fmt 8)
-if(fmt_FOUND)
-  message(STATUS "Using shared fmt ${fmt_VERSION}")
-else()
-  check_vendoring_approved(fmt)
-  message(STATUS "Using static fmt from Externals")
-  add_subdirectory(Externals/fmt EXCLUDE_FROM_ALL)
-endif()
+dolphin_find_optional_system_library(fmt Externals/fmt 8)
+
 add_subdirectory(Externals/imgui)
 add_subdirectory(Externals/implot)
 add_subdirectory(Externals/glslang)
@@ -721,88 +712,30 @@ if(NOT WIN32 OR (NOT (CMAKE_SYSTEM_PROCESSOR STREQUAL "aarch64")))
   add_definitions(-DHAS_OPENGL)
 endif()
 
-find_package(pugixml)
-if(NOT pugixml_FOUND)
-  check_vendoring_approved(pugixml)
-  message(STATUS "Using static pugixml from Externals")
-  add_subdirectory(Externals/pugixml)
-endif()
+dolphin_find_optional_system_library(pugixml Externals/pugixml)
 
-pkg_check_modules(ENET libenet>=1.3.8 IMPORTED_TARGET)
-if(ENET_FOUND)
-  message(STATUS "Using shared enet")
-  dolphin_alias_library(enet::enet PkgConfig::ENET)
-else()
-  check_vendoring_approved(enet)
-  message(STATUS "Using static enet from Externals")
-  add_subdirectory(Externals/enet)
-endif()
+dolphin_find_optional_system_library_pkgconfig(ENET libenet>=1.3.8 enet::enet Externals/enet)
 
 if(NOT XXHASH_FOUND)
   message(STATUS "Using static xxhash from Externals")
   add_subdirectory(Externals/xxhash)
 endif()
 
-find_package(BZip2)
-if(BZIP2_FOUND)
-  message(STATUS "Using shared bzip2")
-else()
-  check_vendoring_approved(bzip2)
-  message(STATUS "Shared bzip2 not found, falling back to the static library")
-  add_subdirectory(Externals/bzip2)
-endif()
+dolphin_find_optional_system_library(BZip2 Externals/bzip2)
 
-# macOS ships with liblzma.dylib but no headers, so check for the headers too
-find_package(LibLZMA)
-if(LIBLZMA_FOUND)
-  # Imported target added in CMake 3.14
-  dolphin_make_imported_target_if_missing(LibLZMA::LibLZMA LIBLZMA)
-  message(STATUS "Using shared lzma")
-else()
-  check_vendoring_approved(lzma)
-  message(STATUS "Shared lzma not found, falling back to the static library")
-  add_subdirectory(Externals/liblzma)
-endif()
+dolphin_find_optional_system_library(LibLZMA Externals/liblzma)
+# Imported target added in CMake 3.14
+dolphin_make_imported_target_if_missing(LibLZMA::LibLZMA LIBLZMA)
 
-pkg_check_modules(ZSTD QUIET libzstd>=1.4.0 IMPORTED_TARGET)
-if(ZSTD_FOUND)
-  message(STATUS "Using shared zstd version: " ${ZSTD_VERSION})
-  dolphin_alias_library(zstd::zstd PkgConfig::ZSTD)
-else()
-  check_vendoring_approved(zstd)
-  message(STATUS "Shared zstd not found, falling back to the static library")
-  add_subdirectory(Externals/zstd)
-endif()
+dolphin_find_optional_system_library_pkgconfig(ZSTD libzstd>=1.4.0 zstd::zstd Externals/zstd)
 
 add_subdirectory(Externals/zlib-ng)
 
-pkg_check_modules(MINIZIP minizip>=3.0.0 IMPORTED_TARGET)
-if(MINIZIP_FOUND)
-  message(STATUS "Using shared minizip")
-  dolphin_alias_library(minizip::minizip PkgConfig::MINIZIP)
-else()
-  check_vendoring_approved(minizip)
-  message(STATUS "Shared minizip not found, falling back to the static library")
-  add_subdirectory(Externals/minizip)
-endif()
+dolphin_find_optional_system_library_pkgconfig(MINIZIP minizip>=3.0.0 minizip::minizip Externals/minizip)
 
-find_package(LZO)
-if(LZO_FOUND)
-  message(STATUS "Using shared lzo")
-else()
-  check_vendoring_approved(lzo)
-  message(STATUS "Using static lzo from Externals")
-  add_subdirectory(Externals/LZO EXCLUDE_FROM_ALL)
-endif()
+dolphin_find_optional_system_library(LZO Externals/LZO)
 
-pkg_check_modules(pc_spng IMPORTED_TARGET spng)
-if (pc_spng_FOUND AND TARGET PkgConfig::pc_spng)
-  message(STATUS "Using the system libspng")
-  dolphin_alias_library(spng::spng PkgConfig::pc_spng)
-else()
-  message(STATUS "Using static libspng from Externals")
-  add_subdirectory(Externals/libspng)
-endif()
+dolphin_find_optional_system_library_pkgconfig(SPNG spng spng::spng Externals/libspng)
 
 # Using static FreeSurround from Externals
 # There is no system FreeSurround library.
@@ -820,85 +753,33 @@ endif()
 add_subdirectory(Externals/soundtouch)
 include_directories(Externals/soundtouch)
 
-find_package(CUBEB)
-if(CUBEB_FOUND)
-  message(STATUS "Using the system cubeb")
-else()
-  check_vendoring_approved(cubeb)
-  message(STATUS "Using static cubeb from Externals")
-  add_subdirectory(Externals/cubeb EXCLUDE_FROM_ALL)
-endif()
+dolphin_find_optional_system_library(CUBEB Externals/cubeb)
 
 if(NOT ANDROID)
+  dolphin_find_optional_system_library(LibUSB Externals/libusb)
   add_definitions(-D__LIBUSB__)
-  find_package(LibUSB)
-  if(LIBUSB_FOUND)
-    message(STATUS "Using shared LibUSB")
-  else()
-    check_vendoring_approved(libusb)
-    message(STATUS "Using static LibUSB from Externals")
-    add_subdirectory(Externals/libusb EXCLUDE_FROM_ALL)
-  endif()
 endif()
 
-find_package(SFML 2.1 COMPONENTS network system)
-if(SFML_FOUND)
-  message(STATUS "Using shared SFML")
-else()
-  check_vendoring_approved(sfml)
-  message(STATUS "Using static SFML from Externals")
-  add_subdirectory(Externals/SFML)
-endif()
+dolphin_find_optional_system_library(SFML Externals/SFML 2.1 COMPONENTS network system)
 
 if(USE_UPNP)
-  find_package(MINIUPNPC 1.6)
-  if(MINIUPNPC_FOUND)
-    message(STATUS "Using shared miniupnpc")
-  else()
-    check_vendoring_approved(miniupnpc)
-    message(STATUS "Using static miniupnpc from Externals")
-    add_subdirectory(Externals/miniupnpc)
-  endif()
+  dolphin_find_optional_system_library(MINIUPNPC Externals/miniupnpc 1.6)
   add_definitions(-DUSE_UPNP)
 endif()
 
-find_package(MBEDTLS 2.28)
-if(MBEDTLS_FOUND)
-  message(STATUS "Using shared mbed TLS")
-else()
-  check_vendoring_approved(mbedtls)
-  message(STATUS "Using static mbed TLS from Externals")
-  add_subdirectory(Externals/mbedtls/ EXCLUDE_FROM_ALL)
-endif()
+dolphin_find_optional_system_library(MBEDTLS Externals/mbedtls 2.28)
 
-find_package(CURL)
-if(CURL_FOUND)
-  message(STATUS "Using shared libcurl")
-else()
-  check_vendoring_approved(curl)
-  message(STATUS "Using static libcurl from Externals")
-  add_subdirectory(Externals/curl EXCLUDE_FROM_ALL)
-endif()
+dolphin_find_optional_system_library(CURL Externals/curl)
 
 if(NOT ANDROID)
-  find_package(Iconv)
-endif()
-
-if(TARGET Iconv::Iconv)
-  message(STATUS "Using shared iconv")
+  dolphin_find_optional_system_library(Iconv Externals/libiconv-1.14)
 else()
-  check_vendoring_approved(iconv)
   message(STATUS "Using static iconv from Externals")
   add_subdirectory(Externals/libiconv-1.14 EXCLUDE_FROM_ALL)
 endif()
 
 if(NOT ANDROID)
-  find_package(HIDAPI)
-  if(NOT HIDAPI_FOUND)
-    check_vendoring_approved(hidapi)
-    message(STATUS "Using static HIDAPI from Externals")
-    add_subdirectory(Externals/hidapi EXCLUDE_FROM_ALL)
-  endif()
+  dolphin_find_optional_system_library(HIDAPI Externals/hidapi)
 endif()
 
 if(USE_DISCORD_PRESENCE)
@@ -911,11 +792,7 @@ if(NOT ENABLE_QT)
   set(USE_MGBA 0)
 endif()
 if(USE_MGBA)
-  find_package(LIBMGBA)
-  if(NOT LIBMGBA_FOUND)
-    message(STATUS "Using static libmgba from Externals")
-    add_subdirectory(Externals/mGBA)
-  endif()
+  dolphin_find_optional_system_library(LIBMGBA Externals/mGBA)
 endif()
 
 find_package(SYSTEMD)