debug_info_test: Run tests based on debug info

debug_info_test calls tests on the given ELF files. When a directory is
supplied, all ELFs will be searched and tested recursively.

BUG=chromium:817648
TEST=debug_info_test /build/kip/usr/lib/debug

Change-Id: Ibcb1ac2de19df9227eb6e242d611ec841d4b589f
Reviewed-on: https://chromium-review.googlesource.com/942465
Commit-Ready: Ting-Yuan Huang <laszio@chromium.org>
Tested-by: Ting-Yuan Huang <laszio@chromium.org>
Reviewed-by: Ting-Yuan Huang <laszio@chromium.org>
Reviewed-by: Yunlian Jiang <yunlian@chromium.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/debug_info_test/whitelist.py b/debug_info_test/whitelist.py
new file mode 100644
index 00000000..99a457c0
--- /dev/null
+++ b/debug_info_test/whitelist.py
@@ -0,0 +1,57 @@
+# Copyright 2018 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import glob
+import re
+
+# Matching a string of length m in an NFA of size n is O(mn^2), but the
+# performance also depends largely on the implementation. It appears to be fast
+# enough according to the tests.
+#
+# The performance bottleneck of this script is readelf. Unless this becomes
+# slower than readelf, don't waste time here.
+def is_whitelisted(list_name, pattern):
+    """chech whether the given pattern is specified in the whitelist.
+
+    Args:
+        list_name: name of the whitelist
+        pattern: the target string
+    Returns:
+        True if matched otherwise False
+    """
+    return pattern and whitelists[list_name].match(pattern)
+
+def prepare_whitelist(patterns):
+    """Join and compile the re patterns.
+
+    Args:
+        patterns: regex patterns.
+    Return:
+        A compiled re object
+    """
+    return re.compile('|'.join(patterns))
+
+def load_whitelists(dirname):
+    """Load whitelists under dirname.
+
+    A whitelist ends with .whitelist.
+
+    Args:
+        dirname: path to the dir.
+    Returns:
+        A dictionary of 'filename' -> whitelist matcher.
+    """
+    wlist = {}
+    for fn in glob.glob(os.path.join(dirname, '*.whitelist')):
+        key = os.path.splitext(os.path.basename(fn))[0]
+        with open(fn, 'r') as f:
+            patterns = f.read().splitlines()
+            patterns = [l for l in patterns if l[0] != '#']
+            patterns = [l for l in patterns if l != '']
+        wlist[key] = prepare_whitelist(patterns)
+    return wlist
+
+
+whitelists = load_whitelists(os.path.dirname(__file__))