syscalls: Scan multiple folders to build complete syscall list

Previously the syscall list was generated only from the include
folder. This is a limitation when the application tries to create
system calls. This patch create a simple way to include these
new syscalls without the application touching the kernel.

This can be enabled by a Kconfig CONFIG_APPLICATION_DEFINED_SYSCALL.
Once enabled the application source directory will be scanned to
find all application defined syscalls.

Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>

CMakeLists.txt

@@ -428,6 +428,12 @@ else()
   set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${syscalls_subdirs_txt})
 endif()
 
+# SYSCALL_INCLUDE_DIRECTORY will include the directories that needs to be
+# searched for syscall declarations if CONFIG_APPLICATION_DEFINED_SYSCALL is set
+if(CONFIG_APPLICATION_DEFINED_SYSCALL)
+  set(SYSCALL_INCLUDE_DIRECTORY --include ${APPLICATION_SOURCE_DIR})
+endif()
+
 add_custom_command(
   OUTPUT
   ${syscalls_json}
@@ -435,6 +441,7 @@ add_custom_command(
   ${PYTHON_EXECUTABLE}
   ${ZEPHYR_BASE}/scripts/parse_syscalls.py
    --include          ${ZEPHYR_BASE}/include        # Read files from this dir
+  ${SYSCALL_INCLUDE_DIRECTORY}
   --json-file        ${syscalls_json}              # Write this file
   DEPENDS ${syscalls_subdirs_trigger} ${PARSE_SYSCALLS_HEADER_DEPENDS}
   )

misc/Kconfig

@@ -249,6 +249,13 @@ config BUILD_OUTPUT_STRIPPED
 	  Build a stripped binary. This will build a zephyr.stripped file need
 	  by some platforms.
 
+config APPLICATION_DEFINED_SYSCALL
+	bool "Scan application folder for any syscall definition"
+	default n
+	help
+	  Scan additional folders inside application source folder
+	  for application defined syscalls.
+
 endmenu
 endmenu
 

scripts/parse_syscalls.py

@@ -94,9 +94,10 @@ def analyze_fn(match_group, fn):
     return (fn, handler, invocation, sys_id, table_entry)
 
 
-def analyze_headers(base_path):
+def analyze_headers(multiple_directories):
     ret = []
 
+    for base_path in multiple_directories:
         for root, dirs, files in os.walk(base_path):
             for fn in files:
 
@@ -125,7 +126,7 @@ def parse_args():
         description=__doc__,
         formatter_class=argparse.RawDescriptionHelpFormatter)
 
-    parser.add_argument("-i", "--include", required=True,
+    parser.add_argument("-i", "--include", required=True, action='append',
                         help="Base include directory")
     parser.add_argument(
         "-j", "--json-file", required=True,