Added support for building on Linux (incl. Android/WSL)

This does not require a compatibility layer (Darling) nor a toolchain
(Theos). Instead, clang and lld from Linux distribution is used with
iOS SDK to compile the natives part (C/Objective-C). Of course, this
also allows compiling on Android with Termux or Windows with WSL.

Makefile

@@ -46,6 +46,12 @@ DEVICE_IP   ?= 127.0.0.1
 DEVICE_PORT ?= 22
 $(warning Building on a jailbroken iOS device.)
 endif
+else ifeq ($(DETECTPLAT),Linux)
+$(warning Building on Linux. Note that all targets may not compile or require external components.)
+IOS         := 0
+# SDKPATH presence is checked later
+BOOTJDK     ?= /usr/bin
+SYSARCH     := $(shell uname -m)
 else
 $(error This platform is not currently supported for building PojavLauncher.)
 endif
@@ -132,23 +138,23 @@ DEPLOY     = \
 	ldid -S$(SOURCEDIR)/entitlements.xml $(WORKINGDIR)/PojavLauncher.app/PojavLauncher; \
 	if [ '$(2)' = '0' ]; then \
 		scp -r -P $(DEVICE_PORT) -o "StrictHostKeyChecking no" -o "UserKnownHostsFile=/dev/null" \
-			$(WORKINGDIR)/libOSMesaOverride.dylib.framework \
-			$(WORKINGDIR)/libawt_xawt.dylib \
+			$(WORKINGDIR)/*.framework \
+			$(WORKINGDIR)/*.dylib \
 			$(WORKINGDIR)/PojavLauncher.app/PojavLauncher \
 			$(SOURCEDIR)/JavaApp/local_out/*.jar \
 			root@$(DEVICE_IP):/var/tmp/; \
 		ssh root@$(DEVICE_IP) -p $(DEVICE_PORT) -t " \
-			mv /var/tmp/libawt_xawt.dylib $(1)/Applications/PojavLauncher.app/Frameworks/libawt_xawt.dylib && \
-			mv /var/tmp/libOSMesaOverride.dylib.framework $(1)/Applications/PojavLauncher.app/Frameworks/libOSMesaOverride.dylib.framework && \
+			mv /var/tmp/*.dylib $(1)/Applications/PojavLauncher.app/Frameworks/ && \
+			mv /var/tmp/*.framework $(1)/Applications/PojavLauncher.app/Frameworks/ && \
 			mv /var/tmp/PojavLauncher $(1)/Applications/PojavLauncher.app/PojavLauncher && \
 			mv /var/tmp/*.jar $(1)/Applications/PojavLauncher.app/libs/ && \
 			cd $(1)/Applications/PojavLauncher.app/Frameworks && \
 			ln -sf libawt_xawt.dylib libawt_headless.dylib && \
 			chown -R 501:501 $(1)/Applications/PojavLauncher.app/*"; \
 	else \
-		sudo rm -rf $(1)/Applications/PojavLauncher.app/Frameworks/libOSMesaOverride.dylib.framework; \
-		sudo mv $(WORKINGDIR)/libawt_xawt.dylib $(1)/Applications/PojavLauncher.app/Frameworks/libawt_xawt.dylib; \
-		sudo mv $(WORKINGDIR)/libOSMesaOverride.dylib.framework $(1)/Applications/PojavLauncher.app/Frameworks/; \
+		sudo rm -rf $(1)/Applications/PojavLauncher.app/Frameworks/{libOSMesaOverride.dylib,MetalANGLE}.framework; \
+		sudo mv $(WORKINGDIR)/*.dylib $(1)/Applications/PojavLauncher.app/Frameworks/; \
+		sudo mv $(WORKINGDIR)/*.framework $(1)/Applications/PojavLauncher.app/Frameworks/; \
 		sudo mv $(WORKINGDIR)/PojavLauncher.app/PojavLauncher $(1)/Applications/PojavLauncher.app/PojavLauncher; \
 		sudo mv $(SOURCEDIR)/JavaApp/local_out/*.jar $(1)/Applications/PojavLauncher.app/libs/; \
 		cd $(1)/Applications/PojavLauncher.app/Frameworks; \
@@ -183,6 +189,12 @@ ifeq ($(call HAS_COMMAND,dpkg-deb --version),1)
 $(error You need to install dpkg-dev)
 endif
 
+ifeq ($(DETECTPLAT),Linux)
+ifeq ($(call HAS_COMMAND,lld),1)
+$(error You need to install lld)
+endif
+endif
+
 ifeq ($(call HAS_COMMAND,nproc --version),1)
 ifeq ($(call HAS_COMMAND,gnproc --version),1)
 $(warning Unable to determine number of threads, defaulting to 2.)
@@ -194,6 +206,10 @@ else
 JOBS   ?= $(shell nproc)
 endif
 
+ifndef SDKPATH
+$(error You need to specify SDKPATH to the path of iPhoneOS.sdk. The SDK version should be 14.0 or newer.)
+endif
+
 # Now for the actual Makefile recipes.
 #  all     - runs clean, native, java, extras, and package.
 #  check   - Makes sure that all variables are correct.
@@ -282,9 +298,9 @@ deb: native java extras
 	$(call DIRCHECK,$(WORKINGDIR)/PojavLauncher.app/libs)
 	$(call DIRCHECK,$(WORKINGDIR)/PojavLauncher.app/libs_caciocavallo)
 	@cp -R $(SOURCEDIR)/Natives/resources/* $(WORKINGDIR)/PojavLauncher.app/ || exit 1
-	@cp $(WORKINGDIR)/libawt_xawt.dylib $(WORKINGDIR)/PojavLauncher.app/Frameworks/ || exit 1
+	@cp $(WORKINGDIR)/*.dylib $(WORKINGDIR)/PojavLauncher.app/Frameworks/ || exit 1
 	@( cd $(WORKINGDIR)/PojavLauncher.app/Frameworks; ln -sf libawt_xawt.dylib libawt_headless.dylib ) || exit 1
-	@cp -R $(WORKINGDIR)/libOSMesaOverride.dylib.framework $(WORKINGDIR)/PojavLauncher.app/Frameworks/ || exit 1
+	@cp -R $(WORKINGDIR)/*.framework $(WORKINGDIR)/PojavLauncher.app/Frameworks/ || exit 1
 	@cp -R $(SOURCEDIR)/JavaApp/libs/* $(WORKINGDIR)/PojavLauncher.app/libs/ || exit 1
 	@cp $(SOURCEDIR)/JavaApp/local_out/*.jar $(WORKINGDIR)/PojavLauncher.app/libs/ || exit 1
 	@cp -R $(SOURCEDIR)/JavaApp/libs_caciocavallo/* $(WORKINGDIR)/PojavLauncher.app/libs_caciocavallo/ || exit 1

Natives/AppDelegate.h

@@ -2,7 +2,7 @@
 //  AppDelegate.h
 //
 
-#import "MGLKit.h"
+#import <UIKit/UIKit.h>
 
 @interface AppDelegate : UIResponder <UIApplicationDelegate, UINavigationControllerDelegate>
 

Natives/CMakeLists.txt

@@ -1,9 +1,15 @@
 cmake_minimum_required(VERSION 3.6)
 project(PojavLauncher)
 
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcommon -fobjc-arc -ObjC")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -target arm64-apple-ios -fcommon -fobjc-arc -ObjC")
 set(CMAKE_C_FLAGS_DEBUG "-funwind-tables -g")
 
+if("${CMAKE_HOST_SYSTEM_NAME}" MATCHES "Linux|^GNU$|Android")
+set(GLOBAL_LDFLAGS "-isysroot ${CMAKE_OSX_SYSROOT} -Wl,-syslibroot,${CMAKE_OSX_SYSROOT} -fuse-ld=lld")
+set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${GLOBAL_LDFLAGS}")
+set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${GLOBAL_LDFLAGS}")
+endif()
+
 include_directories(
   "resources/Frameworks/Alderis.framework/Headers"
   "external/AFNetworking/AFNetworking"
@@ -48,6 +54,7 @@ set_target_properties(libOSMesaOverride.dylib PROPERTIES
     MACOSX_FRAMEWORK_IDENTIFIER dylib.mesa3d.libOSMesaOverride
 )
 target_link_libraries(libOSMesaOverride.dylib
+  "${GLOBAL_LDFLAGS}"
   "${OSMESA_LIB}"
 )
 
@@ -57,6 +64,7 @@ add_library(tinygl4angle SHARED
   external/gl4es/tinygl4angle.c
 )
 target_link_libraries(tinygl4angle
+  "${GLOBAL_LDFLAGS}"
   "-F'${CMAKE_CURRENT_LIST_DIR}/resources/Frameworks'"
   "-framework MetalANGLE"
 )
@@ -118,6 +126,10 @@ add_executable(PojavLauncher
   utils.m
 )
 
+if("${CMAKE_HOST_SYSTEM_NAME}" MATCHES "Linux|^GNU$|Android")
+target_sources(PojavLauncher PUBLIC non_darwin_utils.m)
+endif()
+
 target_link_libraries(PojavLauncher
   "-F'${CMAKE_CURRENT_LIST_DIR}/build'"
   "-F'${CMAKE_CURRENT_LIST_DIR}/resources/Frameworks'"

Natives/non_darwin_utils.m

@@ -0,0 +1,11 @@
+#import <Foundation/Foundation.h>
+
+// This is only compiled when building on non-Apple platforms
+
+int __isPlatformVersionAtLeast(int platform, int major, int minor, int patch) {
+    NSOperatingSystemVersion version;
+    version.majorVersion = major;
+    version.minorVersion = minor;
+    version.patchVersion = patch;
+    return [[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion:version];
+}