Add proper logging mechanism to application

This mechanism has custom coloring, support to dump in file and
on the commandline and support to turn either or both off. cli/cli.py
provies a function that can be called in each module to instantiate
a logger for that module.

srdl2sv/cli/cli.py

@@ -1,29 +1,46 @@
 import argparse
 import os
+import time
+import logging
 from itertools import chain
 
+logging_map = {
+    "DEBUG": logging.DEBUG,
+    "INFO": logging.INFO,
+    "WARNING": logging.WARNING,
+    "ERROR": logging.ERROR,
+    "CRITICAL": logging.CRITICAL,
+    "NONE": logging.NOTSET
+}
+
 class CliArguments():
+
     def __init__(self):
         self.parser = argparse.ArgumentParser(
             description="SystemRDL 2 SystemVerilog compiler")
 
         self.parser.add_argument(
-            "-v",
-            "--verbosity",
-            action="count",
-            help="Increase output verbosity.")
+            "--stream_log_level",
+            choices=['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL', 'NONE'],
+            default='WARNING',
+            help="Set verbosity level of output to shell. When set to 'NONE',\
+                  nothing will be printed to the shell. (default: %(default)s)")
 
         self.parser.add_argument(
-            "-q",
-            "--quiet",
-            action="store_true")
+            "--file_log_level",
+            choices=['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL', 'NONE'],
+            default='INFO',
+            help="Set verbosity level of output to log-file. When set to 'NONE',\
+                  nothing will be printed to the shell. (default: %(default)s)")
 
         self.parser.add_argument(
             "-o",
             "--out_dir",
             type=str,
+            default="./srdl2sv_out",
             help="Define output directory to dump files.\
-                  If directory is non-existent, it will be created.")
+                  If directory is non-existent, it will be created.\
+                  (default: %(default)s)")
 
         self.parser.add_argument(
             "-d",
@@ -49,15 +66,29 @@ class CliArguments():
     def get_config(self) -> dict():
         args = self.parser.parse_args()
 
+        # Create dictionary to save config in
         config = dict()
 
+        # Save input file and output directory to dump everything in
         config['input_file'] = args.IN_RDL
-        config['verbosity'] = args.verbosity
-        config['quiet'] = args.quiet
+        config['output_dir'] = args.out_dir
 
+        # Map logging level string to integers
+        config['stream_log_level'] = logging_map[args.stream_log_level]
+        config['file_log_level'] = logging_map[args.file_log_level]
+
+        # Determine paths to be passed to systemrdl-compiler to search
+        # for include files.
         if args.recursive_search:
             config['search_paths'] = [x[0] for y in args.search_paths for x in os.walk(y)]
         else:
             config['search_paths'] = args.search_paths
 
+        # Save timestamp, so that it can be used across the compiler
+        config['ts'] = time.localtime()
+
+        # Determine name of file to hold logs
+        ts = time.strftime('%Y%m%d_%H%M%S', config['ts'])
+        config['file_log_location'] = "srdl2sv_{}.log".format(ts)
+
         return config

srdl2sv/log/log.py

@@ -0,0 +1,59 @@
+import logging
+from typing import Optional
+
+class CustomFormatter(logging.Formatter):
+    """Logging Formatter to add colors and count warning / errors"""
+
+    MAPPING = {
+        'DEBUG'   : 37, # white
+        'INFO'    : 32, # green
+        'WARNING' : 33, # yellow
+        'ERROR'   : 31, # red
+        'CRITICAL': 41, # white on red bg
+    }
+
+    PREFIX = '\033['
+    SUFFIX = '\033[0m'
+
+    def format(self, record):
+        colored_record = record
+        levelname = colored_record.levelname
+        seq = CustomFormatter.MAPPING.get(levelname, 37) # default white
+        colored_levelname = ('{0}{1}m{2}{3}') \
+            .format(
+                CustomFormatter.PREFIX,
+                seq,
+                levelname,
+                CustomFormatter.SUFFIX)
+        colored_record.levelname = colored_levelname
+
+        return logging.Formatter.format(self, colored_record)
+
+def create_logger (
+        mod_name,
+        stream_log_level: int = logging.WARNING,
+        file_log_level: int = logging.INFO,
+        file_name: Optional[str] = None):
+
+    log = logging.getLogger(mod_name)
+    log.setLevel(min(stream_log_level, file_log_level))
+
+    if file_log_level > 0 and file_name:
+        file_handler = logging.FileHandler(file_name)
+        file_handler.setLevel(file_log_level)
+
+        file_formatter = logging.Formatter(
+            "%(asctime)s - %(levelname)s - %(name)s: %(message)s")
+        file_handler.setFormatter(file_formatter)
+        log.addHandler(file_handler)
+
+    if stream_log_level > 0:
+        stream_handler = logging.StreamHandler()
+        stream_handler.setLevel(stream_log_level)
+
+        stream_formatter = CustomFormatter(
+            "[%(levelname)s][%(name)s] %(message)s")
+        stream_handler.setFormatter(stream_formatter)
+        log.addHandler(stream_handler)
+
+    return log

srdl2sv/main.py

@@ -10,6 +10,7 @@ from systemrdl import RDLCompiler, RDLCompileError
 # Local modules
 from components.addrmap import AddrMap
 from cli.cli import CliArguments
+from log.log import create_logger
 
 if __name__ == "__main__":
     # Take start timestamp
@@ -33,8 +34,9 @@ if __name__ == "__main__":
 
     addrmap = AddrMap(rdlc, root.top)
 
-    print("====================================================")
-    print("Elapsed time: {} seconds".format(time.time() - start))
-    print("====================================================")
-
-
+    logger = create_logger(
+        __name__,
+        stream_log_level=config['stream_log_level'],
+        file_log_level=config['file_log_level'],
+        file_name=config['file_log_location'])
+    logger.info("Elapsed time: %f seconds", time.time() - start)