WIP: Android please

cmake/Cargo.cmake

@@ -23,6 +23,7 @@ function(_corrosion_determine_libs_new target_triple out_libs)
 		list(APPEND args --target=${target_triple})
 	endif()
 	list(APPEND args -- --print=native-static-libs)
+	message(STATUS "Checking native libraries with command: ${CARGO_COMMAND} ${args}")
 	execute_process(
 		COMMAND ${CARGO_COMMAND} ${args}
 		WORKING_DIRECTORY "${CMAKE_BINARY_DIR}/corrosion/required_libs"
@@ -59,7 +60,7 @@ endfunction()
 # SPDX-SnippetEnd
 
 function(_cargo_set_libs target triple)
-	if(NOT "${triple}")
+	if("${triple}")
 		set(cache_var "CARGO_LIBS_${triple}")
 	else()
 		set(cache_var "CARGO_LIBS_HOST")
@@ -99,6 +100,8 @@ function(add_cargo_library target package)
 			else()
 				set(arch i686)
 			endif()
+		else()
+			message(WARNING "Unknown Cargo arch for processor '${CMAKE_SYSTEM_PROCESSOR}'")
 		endif()
 
 		if(WIN32)
@@ -108,16 +111,21 @@ function(add_cargo_library target package)
 			elseif(MINGW)
 				set(abi gnu)
 			endif()
+		elseif(ANDROID)
+			set(sys linux)
+			set(abi android)
 		elseif(CMAKE_SYSTEM_NAME STREQUAL Darwin)
 			set(sys apple)
 			set(abi darwin)
 		elseif(CMAKE_SYSTEM_NAME STREQUAL Linux)
 			set(sys unknown-linux)
 			set(abi gnu)
+		else()
+			message(WARNING "Unknown Cargo sys and abi for system '${CMAKE_SYSTEM_NAME}'")
 		endif()
 
 		if(NOT arch OR NOT sys OR NOT abi)
-			message(WARNING "Unable to determine target ABI for Cargo; using host ABI")
+			message(SEND_ERROR "Unable to determine target ABI for Cargo")
 		else()
 			set(triple ${arch}-${sys}-${abi})
 			message(STATUS "Cargo target ABI: ${triple}")