New platform selection system in build system

CMakeLists.txt

@@ -12,28 +12,10 @@ macro(subdirlist result curdir)
     set(${result} ${dirlist})
 endmacro()
 
-subdirlist(machine_dirs ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/machine)
+include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/platform.cmake)
+platform_config(${TARGET})
 
-if (NOT PLATFORM)
+message(STATUS "Target: ${machine}-${platform}")
-    set(PLATFORM "linux")
-endif ()
-
-if (NOT MACHINE)
-    set(supported_machines "")
-    foreach (dir ${machine_dirs})
-        set(supported_machines "${supported_machines}${dir} ")
-    endforeach (dir)
-
-    message(FATAL_ERROR "No machine architecture specified.\n"
-        " Supported machines: ${supported_machines}\n"
-        " Ex. `cmake -DMACHINE=x86_64 <dir>`")
-endif ()
-
-if (NOT EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM})
-    message(FATAL_ERROR "Unsupported platform: ${PLATFORM}")
-endif ()
-
-message(STATUS "Target platform: ${PLATFORM}")
 
 set(CMAKE_EXE_LINKER_FLAGS
     "${CMAKE_EXE_LINKER_FLAGS} -ffreestanding -nostdlib -lgcc")
@@ -49,22 +31,22 @@ endforeach (dir)
 file(GLOB_RECURSE photon_libc_headers ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/include/*.h)
 
 file(GLOB photon_libc_crt
-    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM}/machine/${MACHINE}/crt*.s)
+    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${platform}/machine/${machine}/crt*.s)
 
 add_library(crt OBJECT ${photon_libc_crt})
 
 file(GLOB platform_sources
-    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM}/*.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${platform}/*.c
-    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM}/machine/${MACHINE}/*.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${platform}/machine/${machine}/*.c
-    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM}/machine/${MACHINE}/*.s)
+    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${platform}/machine/${machine}/*.s)
 
 foreach (crt_source ${photon_libc_crt})
     list(REMOVE_ITEM platform_sources ${crt_source})
 endforeach (crt_source)
 
 file(GLOB platform_headers
-    ${CMAKE_CURRENT_SOURCE_DIR}/photon/sys/${PLATFORM}/*.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/photon/sys/${platform}/*.h
-    ${CMAKE_CURRENT_SOURCE_DIR}/photon/sys/${PLATFORM}/machine/${MACHINE}/*.h)
+    ${CMAKE_CURRENT_SOURCE_DIR}/photon/sys/${platform}/machine/${machine}/*.h)
 
 set(photon_libc_sources ${photon_libc_sources} ${platform_sources})
 set(photon_libc_headers ${photon_libc_headers} ${platform_headers})
@@ -74,14 +56,14 @@ target_compile_options(c PRIVATE -ffreestanding -nostdlib -nostdinc)
 target_link_libraries(c crt)
 
 target_include_directories(c PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/include)
-target_include_directories(c PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM}/)
+target_include_directories(c PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${platform}/)
 
 add_custom_target(sysroot
     DEPENDS ${photon_libc_headers}
     COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/scripts/create-sysroot.sh
         ${CMAKE_CURRENT_SOURCE_DIR}
         ${CMAKE_CURRENT_BINARY_DIR}
-        ${PLATFORM} ${MACHINE})
+        ${platform} ${machine})
 
 add_dependencies(c sysroot)
 

cmake/platform.cmake

@@ -0,0 +1,44 @@
+macro(subdirlist result curdir)
+    file(GLOB children RELATIVE ${curdir} ${curdir}/*)
+    set(dirlist "")
+    foreach (child ${children})
+        if (IS_DIRECTORY ${curdir}/${child})
+            list(APPEND dirlist ${child})
+        endif()
+    endforeach()
+    set(${result} ${dirlist})
+endmacro()
+
+function (platform_config)
+    set(available_platforms "")
+    set(available_platforms_list "")
+    subdirlist(platforms ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys)
+
+    foreach (platform ${platforms})
+        subdirlist(machines ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${platform}/machine)
+        foreach (machine ${machines})
+            set(available_platforms "${available_platforms}${machine}-${platform} ")
+            list(APPEND available_platforms_list ${machine}-${platform})
+        endforeach (machine)
+    endforeach (platform)
+
+    if (${ARGC} LESS 1)
+        message(FATAL_ERROR "No target specified!\n"
+            "Available targets: ${available_platforms}")
+    endif ()
+
+    set(target ${ARGV0})
+
+    list(FIND available_platforms_list ${target} target_idx)
+
+    if (${target_idx} EQUAL -1)
+        message(FATAL_ERROR "${target} is not a valid target!\n"
+        "Available targets: ${available_platforms}")
+    endif ()
+
+    string(REPLACE "-" ";" target_parts ${target})
+    list(GET target_parts 1 platform)
+    list(GET target_parts 0 machine)
+    set(machine ${machine} PARENT_SCOPE)
+    set(platform ${platform} PARENT_SCOPE)
+endfunction (platform_config)