Add a script to display the captured code sizes

This script parses the JSON file we generate and pretty-prints a table
of sizes along with the totals.

Signed-off-by: David Horstmann <david.horstmann@arm.com>

Author: davidhorstmann-arm

scripts/show_code_size.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+"""Parse a JSON code size report and output a pretty-printed table of sizes
+for each module along with their totals.
+"""
+
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+
+import json
+import sys
+
+def display_sizes(json_file):
+    with open(json_file) as f:
+        json_sizes = f.read()
+
+    sizes = json.loads(json_sizes)
+
+    padded_line = '{:<40} {:>8} {:>8} {:>8} {:>8}'
+
+    print(padded_line.format('file', 'text', 'data', 'bss', 'total'))
+
+    text_total = 0
+    data_total = 0
+    bss_total = 0
+    total_total = 0
+
+    for file in sizes:
+        module = file.split('.')[0] # Remove .c.obj extension
+        text = sizes[file]['text']
+        data = sizes[file]['data']
+        bss = sizes[file]['bss']
+        print(padded_line.format(module, text, data, bss, text + data + bss))
+        text_total += text
+        data_total += data
+        bss_total += bss
+        total_total += text + data + bss
+
+    print(padded_line.format('TOTAL', text_total, data_total, bss_total, total_total))
+
+if __name__ == '__main__':
+    if len(sys.argv) < 2:
+        print('Error: No JSON file supplied.', file=sys.stderr)
+        sys.exit(1)
+
+    display_sizes(sys.argv[1])