py: Allow registration of modules at their definition.

During make, makemoduledefs.py parses the current builds c files for
MP_REGISTER_MODULE(module_name, obj_module, enabled_define)

These are used to generate a header with the required entries for
"mp_rom_map_elem_t mp_builtin_module_table[]" in py/objmodule.c

1 files changed, 107 insertions, 0 deletions

diff --git a/py/makemoduledefs.py b/py/makemoduledefs.py
new file mode 100644
index 0000000000..18d327f002
--- /dev/null
+++ b/py/makemoduledefs.py
@@ -0,0 +1,107 @@
+#!/usr/bin/env python
+
+# This pre-processor parses provided objects' c files for
+# MP_REGISTER_MODULE(module_name, obj_module, enabled_define)
+# These are used to generate a header with the required entries for
+# "mp_rom_map_elem_t mp_builtin_module_table[]" in py/objmodule.c
+
+from __future__ import print_function
+
+import re
+import os
+import argparse
+
+
+pattern = re.compile(
+    r"[\n;]\s*MP_REGISTER_MODULE\((.*?),\s*(.*?),\s*(.*?)\);",
+    flags=re.DOTALL
+)
+
+
+def find_c_file(obj_file, vpath):
+    """ Search vpaths for the c file that matches the provided object_file.
+
+    :param str obj_file: object file to find the matching c file for
+    :param List[str] vpath: List of base paths, similar to gcc vpath
+    :return: str path to c file or None
+    """
+    c_file = None
+    relative_c_file = os.path.splitext(obj_file)[0] + ".c"
+    relative_c_file = relative_c_file.lstrip('/\\')
+    for p in vpath:
+        possible_c_file = os.path.join(p, relative_c_file)
+        if os.path.exists(possible_c_file):
+            c_file = possible_c_file
+            break
+
+    return c_file
+
+
+def find_module_registrations(c_file):
+    """ Find any MP_REGISTER_MODULE definitions in the provided c file.
+
+    :param str c_file: path to c file to check
+    :return: List[(module_name, obj_module, enabled_define)]
+    """
+    global pattern
+
+    if c_file is None:
+        # No c file to match the object file, skip
+        return set()
+
+    with open(c_file) as c_file_obj:
+        return set(re.findall(pattern, c_file_obj.read()))
+
+
+def generate_module_table_header(modules):
+    """ Generate header with module table entries for builtin modules.
+
+    :param List[(module_name, obj_module, enabled_define)] modules: module defs
+    :return: None
+    """
+
+    # Print header file for all external modules.
+    mod_defs = []
+    print("// Automatically generated by makemoduledefs.py.\n")
+    for module_name, obj_module, enabled_define in modules:
+        mod_def = "MODULE_DEF_{}".format(module_name.upper())
+        mod_defs.append(mod_def)
+        print((
+            "#if ({enabled_define})\n"
+            "    extern const struct _mp_obj_module_t {obj_module};\n"
+            "    #define {mod_def} {{ MP_ROM_QSTR({module_name}), MP_ROM_PTR(&{obj_module}) }},\n"
+            "#else\n"
+            "    #define {mod_def}\n"
+            "#endif\n"
+            ).format(module_name=module_name, obj_module=obj_module,
+                     enabled_define=enabled_define, mod_def=mod_def)
+        )
+
+    print("\n#define MICROPY_REGISTERED_MODULES \\")
+
+    for mod_def in mod_defs:
+        print("    {mod_def} \\".format(mod_def=mod_def))
+
+    print("// MICROPY_REGISTERED_MODULES")
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--vpath", default=".",
+                        help="comma separated list of folders to search for c files in")
+    parser.add_argument("files", nargs="*",
+                        help="list of c files to search")
+    args = parser.parse_args()
+
+    vpath = [p.strip() for p in args.vpath.split(',')]
+
+    modules = set()
+    for obj_file in args.files:
+        c_file = find_c_file(obj_file, vpath)
+        modules |= find_module_registrations(c_file)
+
+    generate_module_table_header(sorted(modules))
+
+
+if __name__ == '__main__':
+    main()