Script to inline shader into C header file

remoting/tools/build/remoting_c_text_inliner.py

+#!/usr/bin/python
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Helper script to inline files as const char[] into a C header file.
+
+Example:

[Jamie, 2016/06/04 00:24:37]

Make it clear here that a.vert and b.frag are input files.

[Yuwei, 2016/06/04 01:31:42]

Done.

+
+a.vert:
+1"
+2
+3\
+
+b.frag:
+4
+5
+6
+
+remoting_c_text_inliner.py "OUTPUT_H_" "output.h" "a.vert" "b.frag":
+#ifndef OUTPUT_H
+#define OUTPUT_H
+
+const char kAVert[] = "1\"\n"
+ + "2\n"

[Jamie, 2016/06/04 00:24:37]

You can't append string like this in C. Just omitting the '+' should do what you
want, since these are string literals.

[Yuwei, 2016/06/04 01:31:42]

Done.

+ + "3\\";
+
+const char kBFrag[] = "4\n"
+ + "5\n"
+ + "6";
+
+#endif  //  OUTPUT_H
+
+"""
+
+import os.path
+import sys
+
+def escape_line(line):
+  # encode('string-escape') doesn't escape double quote so you need to manually
+  # escape it.
+  return line.encode('string-escape').replace('"', '\\"')
+
+def main():
+  if len(sys.argv) < 4:
+    print 'Usage: remoting_c_text_inliner.py <include-guard> ' + \
+          '<output-file> <input-files...>'
+    return 1
+
+  include_guard = sys.argv[1]
+
+  output_path = sys.argv[2]

[Jamie, 2016/06/04 00:24:37]

Don't need blank lines between these.

[Yuwei, 2016/06/04 01:31:42]

Removed blank line between output_path and include_guard. I think it is okay to
have blank line before open?

+
+  output_file = open(output_path, 'w')
+
+  output_file.write('#ifndef ' + include_guard + '\n' +
+                    '#define ' + include_guard + '\n\n')
+
+  argc = len(sys.argv)
+
+  for i in xrange(3, argc):
+    input_path = sys.argv[i]
+    input_file = open(input_path, 'r')

[Jamie, 2016/06/04 00:24:37]

You can use the "with" keyword to automatically close this when a Python scope
ends.

[Yuwei, 2016/06/04 01:31:42]

Done.

+
+    # hello_world.vert -> kHelloWorldVert
+    const_name = 'k' + os.path.basename(input_path).title().replace('_', '') \
+                 .replace('.', '')

[Jamie, 2016/06/04 00:24:37]

Since you're losing path information when converting to a variable name, I think
you should validate that the names you're producing are all unique so that the
build failure is more obvious.

[Yuwei, 2016/06/04 01:31:42]

Done. Added checks.

+    text = input_file.read()
+    lines = text.splitlines()
+
+    # a, b -> "a, "b -> "a\n" + "b -> "a\n" + "b"

[Jamie, 2016/06/04 00:24:37]

I don't understand this comment.

[Yuwei, 2016/06/04 01:31:42]

Just trying to explain how the strings are concatenated... Changed to more
detailed comments.

+    inlined = '\\n"\n + '.join(map(lambda x: '"' + escape_line(x), lines)) + '"'
+    output_file.write('const char ' + const_name + '[]' + ' = ' + inlined +
+                      ';\n\n')
+    input_file.close()
+
+  output_file.write('#endif  //  ' + include_guard + '\n')
+  output_file.close()
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())