Squashed 'waflib/' changes from 915dcb1..e7a29b6

e7a29b6 Upgrade to waf 2.0.15
8280f9d Add command for running executables from the build directory
8073c1a Make make_simple_dox() safe in case of exception
70d03b8 Avoid use of global counter hacks for configuration display
b7d689a Rewrite test framework
94deadf Automatically add options and move add_flags() to options context
f4259ee Reduce system include path noise
927b608 Automatically display configuration header
c44b8f3 Set line justification from a constant in the wscript
a48e26f Automatically detect if wscript has a test hook
ef66724 Save runtime variables in the environment
63bcbcd Clean up TestContext
b1d9505 Add ExecutionContext for setting runtime environment
387c1df Add show_diff() and test_file_equals() utilities
29d4d29 Fix in-tree library paths
9fde01f Add custom configuration context
6d3612f Add lib_path_name constant

git-subtree-dir: waflib
git-subtree-split: e7a29b6b9b2f842314244c23c14d8f8f560904e1

1 files changed, 38 insertions, 0 deletions

diff --git a/Tools/md5_tstamp.py b/Tools/md5_tstamp.py
new file mode 100644
index 0000000..2a58792
--- /dev/null
+++ b/Tools/md5_tstamp.py
@@ -0,0 +1,38 @@
+#! /usr/bin/env python
+# encoding: utf-8
+
+"""
+Re-calculate md5 hashes of files only when the file time have changed.
+
+The hashes can also reflect either the file contents (STRONGEST=True) or the
+file time and file size.
+
+The performance benefits of this module are usually insignificant.
+"""
+
+import os, stat
+from waflib import Utils, Build, Node
+
+STRONGEST = True
+
+Build.SAVED_ATTRS.append('hashes_md5_tstamp')
+def h_file(self):
+	filename = self.abspath()
+	st = os.stat(filename)
+
+	cache = self.ctx.hashes_md5_tstamp
+	if filename in cache and cache[filename][0] == st.st_mtime:
+		return cache[filename][1]
+
+	if STRONGEST:
+		ret = Utils.h_file(filename)
+	else:
+		if stat.S_ISDIR(st[stat.ST_MODE]):
+			raise IOError('Not a file')
+		ret = Utils.md5(str((st.st_mtime, st.st_size)).encode()).digest()
+
+	cache[filename] = (st.st_mtime, ret)
+	return ret
+h_file.__doc__ = Node.Node.h_file.__doc__
+Node.Node.h_file = h_file
+