Add python script that can add "#pragma once" to all our files.

tools/pragmaonce/pragmaonce.py

Index: tools/pragmaonce/pragmaonce.py
diff --git a/tools/pragmaonce/pragmaonce.py b/tools/pragmaonce/pragmaonce.py
new file mode 100644
index 0000000000000000000000000000000000000000..072cba6cc8409f29378bedfd07faad4a8481a11f
--- /dev/null
+++ b/tools/pragmaonce/pragmaonce.py
@@ -0,0 +1,45 @@
+import re

[Evan Martin, 2010/07/22 00:44:54]

Copyright header plz thx.

[Nico, 2010/07/26 18:54:58]

Presubmit caught this before committing.

+import sys
+
+# A tool to add "#pragma once" lines to files that don't have it yet.
+# Intended usage:
+#   find chrome -name '*.h' -exec  python tools/pragmaonce/pragmaonce.py {} \;

[Evan Martin, 2010/07/22 00:44:54]

nit: extra double space

[Nico, 2010/07/26 18:54:58]

Done.

+
+# Some files have absurdly long comments at the top
+NUM_LINES_TO_SCAN_FOR_GUARD = 250
+
+def main(filename):
+  f = open(filename)
+  lines = f.readlines()
+  f.close()
+
+  index = -1
+  for i in xrange(min(NUM_LINES_TO_SCAN_FOR_GUARD, len(lines) - 1)):
+    m1 = re.match(r'^#ifndef ([A-Z_]+)', lines[i])

[Mark Mentovai, 2010/07/22 02:48:38]

You should likely permit digits too.

[Nico, 2010/07/26 18:54:58]

Since I don't have a "$" at the end, this happened to work. Added digits and a
$.

+    m2 = re.match(r'^#define ([A-Z_]+)', lines[i + 1])
+    if m1 and m2:
+      if m1.group(1) != m2.group(1):
+        print 'Skipping', filename, \
+              ': Broken include guard (%s, %s)' % (m1.group(1), m2.group(1))
+      index = i + 2
+      break
+
+  if index == -1:
+    print 'Skipping', filename, ': no include guard found'
+    return
+
+  if index < len(lines) and re.match(r'#pragma once', lines[index]):
+    # The pragma is already there.
+    return
+
+  lines.insert(index, "#pragma once\n")
+
+  f = open(filename, 'w')
+  f.write(''.join(lines))
+  f.close()
+
+if __name__ == '__main__':
+  if len(sys.argv) != 2:
+    print >>sys.stderr, "Usage: %s inputfile" % sys.argv[0]
+    sys.exit(1)
+  main(sys.argv[1])