Dropping in software construction toolkit.

site_scons/site_tools/replace_strings.py

Index: site_scons/site_tools/replace_strings.py
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--- site_scons/site_tools/replace_strings.py	(revision 0)
+++ site_scons/site_tools/replace_strings.py	(revision 0)
@@ -0,0 +1,81 @@
+#!/usr/bin/python2.4
+# Copyright 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Search and replace builder for SCons."""
+
+
+import re
+import SCons.Script
+
+
+def ReplaceStrings(target, source, env):
+  """Replace Strings builder, does regex substitution on files.
+
+  Args:
+    target: A single target file node.
+    source: A single input file node.
+    env: Environment in which to build.
+
+  From env:
+    REPLACE_STRINGS: A list of pairs of regex search and replacement strings.
+        The body of the source file has substitution performed on each
+        pair (search_regex, replacement) in order.
+
+  Returns:
+    The target node, a file with contents from source, with the substitutions
+    from REPLACE_STRINGS performed on it.
+
+  For example:
+    env.ReplaceStrings('out', 'in',
+                       REPLACE_STRINGS = [('a*', 'b'), ('b', 'CCC')])
+    With 'in' having contents: Haaapy.
+    Outputs: HCCCpy.
+  """
+  # Load text.
+  fh = open(source[0].abspath, 'rb')
+  text = fh.read()
+  fh.close()
+  # Do replacements.
+  for r in env['REPLACE_STRINGS']:
+    text = re.sub(r[0], r[1], text)
+  # Write it out.
+  fh = open(target[0].abspath, 'wb')
+  fh.write(text)
+  fh.close()
+
+
+def generate(env):
+  # NOTE: SCons requires the use of this name, which fails gpylint.
+  """SCons entry point for this tool."""
+
+  # Add the builder
+  act = SCons.Script.Action(ReplaceStrings, varlist=['REPLACE_STRINGS'])
+  bld = SCons.Script.Builder(action=act, single_source=True)
+  env.Append(BUILDERS={'ReplaceStrings': bld})