utils/conv_gen.py: improve application flexibility

This change makes the conv_gen application more interactive
and flexible, allowing to generate not only code definitions
but also the test vectors and header files in the future.
Moreover, it becomes possible to select exact code family,
such as GSM, GMR etc.

Change-Id: I0b476b00234c17f78b41d695cf3bfd13edb64c28

src/gsm/Makefile.am

@@ -35,6 +35,6 @@ EXTRA_DIST = libosmogsm.map
 
 # Convolutional codes generation
 gsm0503_conv.c:
-	$(AM_V_GEN)python2 $(top_srcdir)/utils/conv_gen.py
+	$(AM_V_GEN)python2 $(top_srcdir)/utils/conv_gen.py gen_codes gsm
 
 CLEANFILES = gsm0503_conv.c

utils/conv_gen.py

@@ -23,7 +23,7 @@ mod_license = """
  */
 """
 
-import sys, os, math
+import sys, os, math, argparse
 from functools import reduce
 import conv_codes_gsm
 
@@ -254,13 +254,15 @@ def print_shared(fi, shared_polys):
 		code = ConvolutionalCode(0, polys, name = name)
 		code.print_state_and_output(fi)
 
-def generate_codes(codes, path, prefix):
+def generate_codes(codes, path, prefix, name):
 	# Open a new file for writing
-	f = open(os.path.join(path, prefix + "_conv.c"), 'w')
+	f = open(os.path.join(path, name), 'w')
 	f.write(mod_license + "\n")
 	f.write("#include <stdint.h>\n")
 	f.write("#include <osmocom/core/conv.h>\n\n")
 
+	sys.stderr.write("Generating convolutional codes...\n")
+
 	# Print shared tables first
 	if hasattr(codes, "shared_polys"):
 		print_shared(f, codes.shared_polys)
@@ -279,12 +281,40 @@ def generate_codes(codes, path, prefix):
 
 		code.gen_tables(prefix, f, shared_tables = shared)
 
+def parse_argv():
+	parser = argparse.ArgumentParser()
+
+	# Positional arguments
+	parser.add_argument("action",
+		help = "what to generate",
+		choices = ["gen_codes"])
+	parser.add_argument("family",
+		help = "convolutional code family",
+		choices = ["gsm"])
+
+	# Optional arguments
+	parser.add_argument("-p", "--prefix",
+		help = "internal naming prefix")
+	parser.add_argument("-n", "--target-name",
+		help = "target name for generated file")
+	parser.add_argument("-P", "--target-path",
+		help = "target path for generated file")
+
+	return parser.parse_args()
+
 if __name__ == '__main__':
-	path = sys.argv[1] if len(sys.argv) > 1 else os.getcwd()
+	# Parse and verify arguments
+	argv = parse_argv()
+	path = argv.target_path or os.getcwd()
 
-	sys.stderr.write("Generating convolutional codes...\n")
+	# Determine convolutional code family
+	if argv.family == "gsm":
+		codes = conv_codes_gsm
+		prefix = argv.prefix or "gsm0503"
 
-	# Generate GSM specific codes
-	generate_codes(conv_codes_gsm, path, "gsm0503")
+	# What to generate?
+	if argv.action == "gen_codes":
+		name = argv.target_name or prefix + "_conv.c"
+		generate_codes(codes, path, prefix, name)
 
 	sys.stderr.write("Generation complete.\n")