feat: make osal an interface library

Expose a osal-interface target that is of cmake INTERFACE type.
This target only defines the osal API and allow delaying the
choice of linking of final osal port implementation to the
link stage of the binary. This allow the Osal implementation
to be defined by the integrator of used libraries.

To accomplish this:
- osal.h becomes static and common to all targets
- osal_sys.h is changed to an internal implementation
  header for the osal port
- Build files are restructured to keep build configuration of
  a port in the port directory

By default an osal cmake alias is added to remain
compatible with previous solutions.

Author: elupus

CMakeLists.txt

@@ -52,49 +52,31 @@ configure_file (
   ${OSAL_BINARY_DIR}/src/version.h
   )
 
-# Add platform-dependent targets early, so they can be configured by
-# platform
-add_library(osal "")
-
-# Suppress certain warnings when building with MSVC
-if (WINDOWS_MONO)
-target_compile_options (osal
-  PRIVATE
-  /wd4820 # padding added
-  )
-endif()
+add_library(osal-interface INTERFACE)
 
-# Use position independent code if platform supports shared libraries
-get_property(SUPPORTS_SHARED GLOBAL PROPERTY TARGET_SUPPORTS_SHARED_LIBS)
-if (SUPPORTS_SHARED)
-  set_property(TARGET osal PROPERTY POSITION_INDEPENDENT_CODE ON)
-endif()
+target_include_directories(osal-interface
+  INTERFACE
+  $<BUILD_INTERFACE:${OSAL_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include>
+  )
 
 if (CMAKE_PROJECT_NAME STREQUAL OSAL AND BUILD_TESTING)
   add_executable(osal_test "")
 endif()
 
+# The default system implementation of the OSAL
+# is defined by the build platform, but we provide
+# a common help string here.
+set (OSAL_DEFAULT_SYSTEM_HELP_STRING "The default Osal system implementation to use")
+
 # Platform configuration
 include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/${CMAKE_SYSTEM_NAME}.cmake)
 
-set_target_properties (osal
-  PROPERTIES
-  C_STANDARD 99
-  )
-
-target_compile_features(osal PUBLIC c_std_99)
-
-target_include_directories(osal
-  PUBLIC
-  $<BUILD_INTERFACE:${OSAL_SOURCE_DIR}/include>
-  $<INSTALL_INTERFACE:include>
-  PRIVATE
-  src
-  ${OSAL_BINARY_DIR}/src
-  )
+# Add alias target for the default system
+add_library(osal ALIAS ${OSAL_DEFAULT_SYSTEM})
 
 install(
-  TARGETS osal
+  TARGETS osal-interface
   EXPORT OsalTargets
   )
 
@@ -124,7 +106,6 @@ install(FILES
   )
 
 install(FILES
-  include/sys/osal_cc_clang.h
   include/sys/osal_cc_gcc.h
   include/sys/osal_cc_msvc.h
   include/sys/osal_cc_rtk.h

cmake/Linux.cmake

@@ -12,45 +12,14 @@
 # license. See the file LICENSE distributed with this software for
 # full license information.
 #*******************************************************************/
-
 find_package(Threads)
 
-option (USE_SCHED_FIFO
-  "Use SCHED_FIFO policy. May require extra privileges to run"
-  OFF)
-
-target_sources(osal PRIVATE
-  src/linux/osal.c
-  src/linux/osal_log.c
-  )
-
-target_compile_options(osal
-  PRIVATE
-  -Wall
-  -Wextra
-  -Werror
-  -Wno-unused-parameter
-  $<$<BOOL:${USE_SCHED_FIFO}>:-DUSE_SCHED_FIFO>
-  INTERFACE
-  $<$<CONFIG:Coverage>:--coverage>
-  )
-
-target_include_directories(osal PUBLIC
-  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src/linux>
-  )
-
-target_link_libraries(osal PUBLIC
-  Threads::Threads
-  rt
-  INTERFACE
-  $<$<CONFIG:Coverage>:--coverage>
-  )
-
-install(FILES
-  src/linux/sys/osal_sys.h
-  DESTINATION include/sys
-  )
+add_subdirectory(src/linux)
 
 if (BUILD_TESTING)
   set(GOOGLE_TEST_INDIVIDUAL TRUE)
 endif()
+
+set (OSAL_DEFAULT_SYSTEM
+  osal-linux
+  CACHE STRING ${OSAL_DEFAULT_SYSTEM_HELP_STRING})

cmake/OsalConfig.cmake.in

@@ -7,3 +7,11 @@ endif()
 @PACKAGE_INIT@
 
 include ( "${CMAKE_CURRENT_LIST_DIR}/OsalTargets.cmake" )
+
+set (OSAL_DEFAULT_SYSTEM @OSAL_DEFAULT_SYSTEM@ CACHE STRING "@OSAL_DEFAULT_SYSTEM_HELP_STRING@")
+
+if (TARGET ${OSAL_DEFAULT_SYSTEM})
+    add_library (osal ALIAS ${OSAL_DEFAULT_SYSTEM})
+else()
+    message (VERBOSE "Osal default system not available yet")
+endif()

cmake/STM32Cube.cmake

@@ -13,31 +13,18 @@
 # full license information.
 #*******************************************************************/
 
-target_sources(osal PRIVATE
-  src/freertos/osal.c
-  src/freertos/osal_log.c
-  )
-
-target_compile_options(osal
-  PRIVATE
-  -Wall
-  -Wextra
-  -Werror
-  -Wno-unused-parameter
-  )
-
-target_include_directories(osal PUBLIC
-  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src/freertos>
-  )
-
-install(FILES
-  src/freertos/sys/osal_sys.h
-  DESTINATION include/sys
-  )
-
 add_library(cube)
-target_link_libraries(osal cube)
 install(TARGETS cube EXPORT OsalTargets)
 
 set(CORE_DIR src/freertos/${BOARD})
 include(STM32Cube/${BOARD})
+
+add_subdirectory(src/freertos)
+target_link_libraries(osal-freertos
+  PRIVATE
+  cube
+  )
+
+set (OSAL_DEFAULT_SYSTEM
+  osal-freertos
+  CACHE STRING ${OSAL_DEFAULT_SYSTEM_HELP_STRING})

cmake/Windows.cmake

@@ -13,45 +13,12 @@
 # full license information.
 #*******************************************************************/
 
-target_sources(osal PRIVATE
-  src/windows/osal.c
-  src/windows/osal_log.c
-  )
-
-target_compile_options(osal
-  PRIVATE
-  $<$<C_COMPILER_ID:MSVC>:
-    /W4
-    /WX
-    /wd4100
-    /wd4152
-  >
-
-  $<$<C_COMPILER_ID:GCC>:
-    -Wall
-    -Wextra
-    -Werror
-    -Wno-unused-parameter
-  >
-
-  PUBLIC
-  $<$<C_COMPILER_ID:MSVC>:
-    /wd4200
-  >
-  )
-
-target_link_libraries(osal
-  winmm)
-
-target_include_directories(osal PUBLIC
-  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src/windows>
-  )
-
-install(FILES
-  src/windows/sys/osal_sys.h
-  DESTINATION include/sys
-  )
+add_subdirectory(src/windows)
 
 if (BUILD_TESTING)
   set(GOOGLE_TEST_INDIVIDUAL TRUE)
 endif()
+
+set (OSAL_DEFAULT_SYSTEM
+  osal-windows
+  CACHE STRING ${OSAL_DEFAULT_SYSTEM_HELP_STRING})

cmake/iMX8MM.cmake

@@ -14,24 +14,18 @@
 # full license information.
 #*******************************************************************/
 
-target_sources(osal PRIVATE
-  src/freertos/osal.c
-  src/freertos/osal_log.c
-  )
-
-target_include_directories(osal PUBLIC
-  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src/freertos/>
-  )
-
-install(FILES
-  src/freertos/sys/osal_sys.h
-  DESTINATION include/sys
-  )
-
 add_library(mcuxsdk)
-target_link_libraries(osal mcuxsdk)
 install(TARGETS mcuxsdk EXPORT OsalTargets)
 
-
 set(CORE_DIR src/freertos/${BOARD})
 include(MCUXSDK/${BOARD})
+
+add_subdirectory(src/freertos)
+target_link_libraries(osal-freertos
+  PRIVATE
+  cube
+  )
+
+set (OSAL_DEFAULT_SYSTEM
+  osal-freertos
+  CACHE STRING ${OSAL_DEFAULT_SYSTEM_HELP_STRING})

cmake/rt-kernel.cmake

@@ -13,28 +13,8 @@
 # full license information.
 #*******************************************************************/
 
-target_sources(osal PRIVATE
-  src/rt-kernel/osal.c
-  src/rt-kernel/osal_log.c
-  )
+add_subdirectory(src/rt-kernel)
 
-target_compile_options(osal
-  PRIVATE
-  -Wall
-  -Wextra
-  -Werror
-  -Wno-unused-parameter
-  )
-
-target_link_libraries(osal
-  kern
-  )
-
-target_include_directories(osal PUBLIC
-  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src/rt-kernel>
-  )
-
-install(FILES
-  src/rt-kernel/sys/osal_sys.h
-  DESTINATION include/sys
-  )
+set (OSAL_DEFAULT_SYSTEM
+  osal-rt-kernel
+  CACHE STRING ${OSAL_DEFAULT_SYSTEM_HELP_STRING})

include/osal.h

@@ -25,7 +25,6 @@ extern "C" {
 #include <stdint.h>
 #include <stdbool.h>
 
-#include "sys/osal_sys.h"
 #include "sys/osal_cc.h"
 
 #ifndef MIN
@@ -44,41 +43,19 @@ extern "C" {
 #define NELEMENTS(a) (sizeof (a) / sizeof ((a)[0]))
 #endif
 
-#ifndef OS_WAIT_FOREVER
 #define OS_WAIT_FOREVER 0xFFFFFFFF
-#endif
 
 #ifndef OS_MAIN
 #define OS_MAIN int main
 #endif
 
-#ifndef OS_MUTEX
-typedef void os_mutex_t;
-#endif
-
-#ifndef OS_SEM
-typedef void os_sem_t;
-#endif
-
-#ifndef OS_THREAD
-typedef void os_thread_t;
-#endif
-
-#ifndef OS_EVENT
-typedef void os_event_t;
-#endif
-
-#ifndef OS_MBOX
-typedef void os_mbox_t;
-#endif
-
-#ifndef OS_TIMER
-typedef void os_timer_t;
-#endif
-
-#ifndef OS_TICK
-typedef void os_tick_t;
-#endif
+typedef struct os_mutex os_mutex_t;
+typedef struct os_sem os_sem_t;
+typedef struct os_thread os_thread_t;
+typedef struct os_event os_event_t;
+typedef struct os_mbox os_mbox_t;
+typedef struct os_timer os_timer_t;
+typedef uint64_t os_tick_t;
 
 void * os_malloc (size_t size);
 void os_free (void * ptr);

include/sys/osal_cc.h

@@ -15,10 +15,8 @@
 
 #if defined(__rtk__)
 #include "osal_cc_rtk.h"
-#elif defined(__GNUC__) || defined(__GNUG__)
+#elif defined(__GNUC__) || defined(__GNUG__) || defined(__clang__)
 #include "osal_cc_gcc.h"
-#elif defined(__clang__)
-#include "osal_cc_clang.h"
 #elif defined(_MSC_VER)
 #include "osal_cc_msvc.h"
 #else