Refactor `mk_pat_db()` so that it is usable externally via a new function

``mk_pat_db_internal()`` which is called by a new ``mk_pat_db.py`` script. This
will allow other build systems to generate the ``database.h`` file.

scripts/mk_pat_db.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+"""
+Reads a pattern database and generates the corresponding
+header file.
+"""
+import mk_util
+import argparse
+import logging
+import os
+import sys
+
+def main(args):
+  logging.basicConfig(level=logging.INFO)
+  parser = argparse.ArgumentParser(description=__doc__)
+  parser.add_argument("db_file", help="pattern database file")
+  parser.add_argument("output_file", help="output header file path")
+  pargs = parser.parse_args(args)
+
+  if not os.path.exists(pargs.db_file):
+    logging.error('"{}" does not exist'.format(pargs.db_file))
+    return 1
+
+  if (os.path.exists(pargs.output_file) and
+     not os.path.isfile(pargs.output_file)):
+       logging.error('Refusing to overwrite "{}"'.format(
+         pargs.output_file))
+       return 1
+
+  mk_util.mk_pat_db_internal(pargs.db_file, pargs.output_file)
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))
+

scripts/mk_util.py

@@ -2602,16 +2602,19 @@ def exec_pyg_scripts():
 # database.smt ==> database.h
 def mk_pat_db():
     c = get_component(PATTERN_COMPONENT)
-    fin  = open(os.path.join(c.src_dir, 'database.smt2'), 'r')
-    fout = open(os.path.join(c.src_dir, 'database.h'), 'w')
-    fout.write('static char const g_pattern_database[] =\n')
-    for line in fin:
-        fout.write('"%s\\n"\n' % line.strip('\n'))
-    fout.write(';\n')
-    fin.close()
-    fout.close()
+    fin  = os.path.join(c.src_dir, 'database.smt2')
+    fout = os.path.join(c.src_dir, 'database.h')
+    mk_pat_db_internal(fin, fout)
+
+def mk_pat_db_internal(inputFilePath, outputFilePath):
+    with open(inputFilePath, 'r') as fin:
+        with open(outputFilePath, 'w') as fout:
+            fout.write('static char const g_pattern_database[] =\n')
+            for line in fin:
+                fout.write('"%s\\n"\n' % line.strip('\n'))
+            fout.write(';\n')
     if VERBOSE:
-        print("Generated '%s'" % os.path.join(c.src_dir, 'database.h'))
+        print("Generated '%s'" % outputFilePath)
 
 # Update version numbers
 def update_version():