Integrate support for building with dependencies from vcpkg (#1880)

* Integrate support for building with dependencies from vcpkg

Configure the build using -DUSE_VCPKG=ON to use vcpkg. By default
recommended triplets targeting the OS versions official builds support
are used. You can opt out of this with -DUSE_RECOMMENDED_TRIPLETS=OFF.

* Add the vcpkg manifest

* Fetch vcpkg with FetchContent if we don't have it

* macOS cross compiling fixes

- can't use the x86_64 one as host triplet on arm64 because building Qt
  fails for whatever reason. Because of course it does :D
- vcpkg doesn't always like periods in triplet names so removed those

* x86_64 macOS should also use its recommended target when building arm64 builds

3 files changed, 114 insertions, 0 deletions

diff --git a/cmake/ConfigureVcpkg.cmake b/cmake/ConfigureVcpkg.cmake
new file mode 100644
index 0000000..f7f7f62
--- /dev/null
+++ b/cmake/ConfigureVcpkg.cmake
@@ -0,0 +1,90 @@
+include(FetchContent)
+
+set(_DEFAULT_VCPKG_ROOT "${CMAKE_SOURCE_DIR}/vcpkg")
+set(VCPKG_ROOT "${_DEFAULT_VCPKG_ROOT}" CACHE STRING "The path to the vcpkg repository")
+
+if (VCPKG_ROOT STREQUAL "${_DEFAULT_VCPKG_ROOT}")
+    FetchContent_Declare(vcpkg
+        GIT_REPOSITORY "https://github.com/Microsoft/vcpkg.git"
+        GIT_TAG 2023.10.19
+        SOURCE_DIR "${CMAKE_SOURCE_DIR}/vcpkg")
+    FetchContent_MakeAvailable(vcpkg)
+endif()
+
+set(VCPKG_OVERLAY_TRIPLETS "${CMAKE_SOURCE_DIR}/cmake/overlay-triplets")
+
+option(USE_RECOMMENDED_TRIPLETS "Use the recommended triplets that are used for official builds" ON)
+
+if (CMAKE_OSX_ARCHITECTURES MATCHES ";")
+    message(FATAL_ERROR "macOS universal builds are not supported. Build them individually and combine afterwards instead.")
+endif()
+
+if (USE_RECOMMENDED_TRIPLETS)
+    execute_process(
+        COMMAND uname -m
+        OUTPUT_VARIABLE _HOST_PROCESSOR
+        OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+    set(_CAN_TARGET_AS_HOST OFF)
+
+    if (APPLE)
+        if (NOT CMAKE_OSX_ARCHITECTURES)
+            if (_HOST_PROCESSOR STREQUAL arm64)
+                set(CMAKE_OSX_ARCHITECTURES arm64)
+            else()
+                set(CMAKE_OSX_ARCHITECTURES x86_64)
+            endif()
+        endif()
+
+        if (CMAKE_OSX_ARCHITECTURES STREQUAL arm64)
+            set(_WANTED_TRIPLET arm64-osx-11-release)
+            set(CMAKE_OSX_DEPLOYMENT_TARGET 11.0)
+        else()
+            set(_WANTED_TRIPLET x64-osx-1015-release)
+            set(CMAKE_OSX_DEPLOYMENT_TARGET 10.15)
+        endif()
+    elseif(WIN32)
+        # TODO Windows arm64 if possible
+        set(_CAN_TARGET_AS_HOST ON)
+        set(_WANTED_TRIPLET x64-mingw-static)
+    endif()
+
+    # Don't override it if the user set something else
+    if (NOT VCPKG_TARGET_TRIPLET)
+        set(VCPKG_TARGET_TRIPLET "${_WANTED_TRIPLET}")
+    else()
+        set(_WANTED_TRIPLET "${VCPKG_TARGET_TRIPLET}")
+    endif()
+
+    if (APPLE)
+        if (_HOST_PROCESSOR MATCHES arm64)
+            if (_WANTED_TRIPLET MATCHES "^arm64-osx-")
+                set(_CAN_TARGET_AS_HOST ON)
+            elseif (_WANTED_TRIPLET STREQUAL "x64-osx-1015-release")
+                # Use the default triplet for when building for arm64
+                # because we're probably making a universal build
+                set(VCPKG_HOST_TRIPLET arm64-osx-11-release)
+            endif()
+        else()
+            if (_WANTED_TRIPLET MATCHES "^x64-osx-")
+                set(_CAN_TARGET_AS_HOST ON)
+            elseif (_WANTED_TRIPLET STREQUAL "arm64-osx-11-release")
+                set(VCPKG_HOST_TRIPLET x64-osx-1015-release)
+            endif()
+        endif()
+    endif()
+
+    # If host and target triplet differ, vcpkg seems to always assume that the host can't run the target's binaries.
+    # In cases like cross compiling from ARM -> Intel macOS, or target being an older version of the host OS, we *can* do that so the packages built targeting the host are redundant.
+    if (_CAN_TARGET_AS_HOST AND NOT VCPKG_HOST_TRIPLET)
+        option(VCPKG_TARGET_AS_HOST "Use the target as host triplet to speed up builds" ON)
+    else()
+        option(VCPKG_TARGET_AS_HOST "Use the target as host triplet to speed up builds" OFF)
+    endif()
+
+    if (VCPKG_TARGET_AS_HOST)
+        set(VCPKG_HOST_TRIPLET "${VCPKG_TARGET_TRIPLET}" CACHE STRING "Host triplet to use for vcpkg")
+    endif()
+endif()
+
+set(CMAKE_TOOLCHAIN_FILE "${VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake")
diff --git a/cmake/overlay-triplets/arm64-osx-11-release.cmake b/cmake/overlay-triplets/arm64-osx-11-release.cmake
new file mode 100644
index 0000000..7c4b43a
--- /dev/null
+++ b/cmake/overlay-triplets/arm64-osx-11-release.cmake
@@ -0,0 +1,12 @@
+set(VCPKG_TARGET_ARCHITECTURE arm64)
+set(VCPKG_CRT_LINKAGE dynamic)
+set(VCPKG_LIBRARY_LINKAGE static)
+
+set(VCPKG_CMAKE_SYSTEM_NAME Darwin)
+set(VCPKG_CMAKE_SYSTEM_VERSION 11.0)
+set(VCPKG_OSX_ARCHITECTURES arm64)
+set(VCPKG_BUILD_TYPE release)
+set(VCPKG_OSX_DEPLOYMENT_TARGET 11.0)
+
+set(VCPKG_C_FLAGS -mmacosx-version-min=11.0)
+set(VCPKG_CXX_FLAGS -mmacosx-version-min=11.0)
diff --git a/cmake/overlay-triplets/x64-osx-1015-release.cmake b/cmake/overlay-triplets/x64-osx-1015-release.cmake
new file mode 100644
index 0000000..fcb67a7
--- /dev/null
+++ b/cmake/overlay-triplets/x64-osx-1015-release.cmake
@@ -0,0 +1,12 @@
+set(VCPKG_TARGET_ARCHITECTURE x64)
+set(VCPKG_CRT_LINKAGE dynamic)
+set(VCPKG_LIBRARY_LINKAGE static)
+
+set(VCPKG_CMAKE_SYSTEM_NAME Darwin)
+set(VCPKG_CMAKE_SYSTEM_VERSION 10.15)
+set(VCPKG_OSX_ARCHITECTURES x86_64)
+set(VCPKG_BUILD_TYPE release)
+set(VCPKG_OSX_DEPLOYMENT_TARGET 10.15)
+
+set(VCPKG_C_FLAGS -mmacosx-version-min=10.15)
+set(VCPKG_CXX_FLAGS -mmacosx-version-min=10.15)