Cmake build generator support: build stage

Multi-target architecture implementation:
    each root source code directory presents the one
    *INTERFACE* target to it's subdirectory subtargets
    that link only as *STATIC* library.
    For instance, *arch* directory presents *Architecture* target
    then *Architecture* target has *CPUID*, *IO*, *PORT*
    and etc. dependencies

Exact order of linking targets is: boot.o CRTIBUNDLE <TARGETS> CRTNBUNDLE.
Sequence destruction cause to UB. Please to pay attention to this.

TODO
- Debug information
- Build type
- Toolchain file
- Image creation
- Build by WinGW compiler on Windows platform (optional)

Signed-off-by: Alexey Gavrilov <alexey.gavrilov@mail.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/libgcc/CMakeLists.txt b/libgcc/CMakeLists.txt
new file mode 100644
index 0000000..b5b2abc
--- /dev/null
+++ b/libgcc/CMakeLists.txt
@@ -0,0 +1,25 @@
+macro(setup_crt_object_file object_file target_name)
+    execute_process(
+        COMMAND ${CMAKE_CXX_COMPILER} --print-file-name=${object_file}
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+        OUTPUT_VARIABLE PATH
+        ERROR_VARIABLE ERROR_MESSAGE
+        RESULT_VARIABLE RESULT
+    )
+
+    if(RESULT)
+        message(FATAL_ERROR ${ERROR_MESSAGE})
+    endif()
+
+    add_library(${target_name} OBJECT IMPORTED GLOBAL)
+    set_target_properties(${target_name} PROPERTIES
+        IMPORTED_OBJECTS ${PATH}
+    )
+
+endmacro()
+
+# TODO: set platform specific CRT objects
+setup_crt_object_file(crtbegin.o CRTBEGIN)
+setup_crt_object_file(crtend.o CRTEND)
+
+add_subdirectory(${ARCH})