build: Define DECL_CONSTANT mechanism for defining exported constants

Add a DECL_CONSTANT macro to allow the firmware to define constants
that are to be exported to the host during the "identify" phase.  This
replaces the existing hardcoded mechanism of scanning the Kconfig
header file for certain constants.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 15 insertions, 28 deletions

diff --git a/scripts/buildcommands.py b/scripts/buildcommands.py
index 9b6acb45..c0584d15 100644
--- a/scripts/buildcommands.py
+++ b/scripts/buildcommands.py
@@ -21,25 +21,6 @@ def error(msg):
     sys.stderr.write(msg + "\n")
     sys.exit(-1)
 
-# Parser for constants in simple C header files.
-def scan_config(file):
-    f = open(file, 'r')
-    opts = {}
-    for l in f.readlines():
-        parts = l.split()
-        if len(parts) != 3:
-            continue
-        if parts[0] != '#define':
-            continue
-        value = parts[2]
-        if value.isdigit() or (value.startswith('0x') and value[2:].isdigit()):
-            value = int(value, 0)
-        elif value.startswith('"'):
-            value = value[1:-1]
-        opts[parts[1]] = value
-    f.close()
-    return opts
-
 
 ######################################################################
 # Command and output parser generation
@@ -145,7 +126,7 @@ const uint8_t command_index_size PROGMEM = ARRAY_SIZE(command_index);
 ######################################################################
 
 def build_identify(cmd_by_id, msg_to_id, responses, static_strings
-                   , config, version):
+                   , constants, version):
     #commands, messages, static_strings
     messages = dict((msgid, msg) for msg, msgid in msg_to_id.items())
     data = {}
@@ -153,9 +134,7 @@ def build_identify(cmd_by_id, msg_to_id, responses, static_strings
     data['commands'] = sorted(cmd_by_id.keys())
     data['responses'] = sorted(responses)
     data['static_strings'] = static_strings
-    configlist = ['MCU', 'CLOCK_FREQ', 'SERIAL_BAUD']
-    data['config'] = dict((i, config['CONFIG_'+i]) for i in configlist
-                          if 'CONFIG_'+i in config)
+    data['config'] = constants
     data['version'] = version
 
     # Format compressed info into C code
@@ -223,7 +202,7 @@ def build_version(extra):
 ######################################################################
 
 def main():
-    usage = "%prog [options] <cmd section file> <autoconf.h> <output.c>"
+    usage = "%prog [options] <cmd section file> <output.c>"
     opts = optparse.OptionParser(usage)
     opts.add_option("-e", "--extra", dest="extra", default="",
                     help="extra version string to append to version")
@@ -233,9 +212,9 @@ def main():
                     help="enable debug messages")
 
     options, args = opts.parse_args()
-    if len(args) != 3:
+    if len(args) != 2:
         opts.error("Incorrect arguments")
-    incmdfile, inheader, outcfile = args
+    incmdfile, outcfile = args
     if options.verbose:
         logging.basicConfig(level=logging.DEBUG)
 
@@ -245,6 +224,7 @@ def main():
                             for m in msgproto.DefaultMessages.values())
     parsers = []
     static_strings = []
+    constants = {}
     # Parse request file
     f = open(incmdfile, 'rb')
     data = f.read()
@@ -280,6 +260,14 @@ def main():
             parsers.append((None, msg))
         elif cmd == '_DECL_STATIC_STR':
             static_strings.append(req[17:])
+        elif cmd == '_DECL_CONSTANT':
+            name, value = parts[1:]
+            value = value.strip()
+            if value.startswith('"') and value.endswith('"'):
+                value = value[1:-1]
+            if name in constants and constants[name] != value:
+                error("Conflicting definition for constant '%s'" % name)
+            constants[name] = value
         else:
             error("Unknown build time command '%s'" % cmd)
     # Create unique ids for each message type
@@ -299,13 +287,12 @@ def main():
     cmdcode = build_commands(cmd_by_id, messages_by_name, all_param_types)
     paramcode = build_param_types(all_param_types)
     # Create identify information
-    config = scan_config(inheader)
     version = build_version(options.extra)
     sys.stdout.write("Version: %s\n" % (version,))
     responses = [msg_to_id[msg] for msgname, msg in messages_by_name.items()
                  if msgname not in commands]
     datadict, icode = build_identify(cmd_by_id, msg_to_id, responses
-                                     , static_strings, config, version)
+                                     , static_strings, constants, version)
     # Write output
     f = open(outcfile, 'wb')
     f.write(FILEHEADER + paramcode + parsercode + cmdcode + icode)