Add test_image script for checking that dependencies in image are sane

src/scripts/check_deps

Index: src/scripts/check_deps
diff --git a/src/scripts/check_deps b/src/scripts/check_deps
new file mode 100755
index 0000000000000000000000000000000000000000..a7f244bf9710ac41f8a43dab8dc81a6edfb2663e
--- /dev/null
+++ b/src/scripts/check_deps
@@ -0,0 +1,117 @@
+#!/usr/bin/python
+
+# Copyright (c) 2010 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 re
+import sys
+
+SHARED_RE = re.compile(r"Shared library: \[([^\]]+)\]")

[kmixter1, 2010/03/01 23:37:33]

Usually prefix these with _ if they're internal constants

+RPATH_RE = re.compile(r"Library rpath: \[([^\]]+)\]")
+
+
+class CheckDependencies(object):
+  """Check that dependencies for binaries can be found in the specified dir."""
+
+  def __init__(self, root, verbose=False):
+    """Initializer.
+
+    Args:
+      root: The sysroot (e.g. "/")
+      verbose: Print helpful messages.
+    """
+
+    self.root = root

[kmixter1, 2010/03/01 23:37:33]

prefix these with _ if they're internal class variables.

+    self.errors = False

[kmixter1, 2010/03/01 23:37:33]

Not used.

+    self.system_libcache = set()
+    self.verbose = verbose
+
+    # Insert some default directories into our library cache.
+    # The /usr/lib/nss and /usr/lib/nspr directories are
+    # required for understanding old-style Netscape plugins.
+    self._ReadLibs([
+        "%s/lib" % root,
+        "%s/usr/lib" % root,
+        "%s/usr/lib/nss" % root,
+        "%s/usr/lib/nspr" % root
+    ], self.system_libcache)
+
+  def _ReadLibs(self, paths, libcache):
+    for path in paths:
+      if os.path.exists(path):
+        for lib in os.listdir(path):

[kmixter1, 2010/03/01 23:37:33]

So you're assuming any file in one of the libcache directories is a shared
object.  Might be worth a comment to that effect.

+          libcache.add(lib)
+
+  def _ReadDependencies(self, binary, libcache):

[kmixter1, 2010/03/01 23:37:33]

So reading the dependencies of a binary also updates the libcache for library
rpaths.  Please add comment as that's not obvious from the name of the function
- also comment that you'll want to operate on a copy of the system libraries.

+    libs = []
+
+    # Read list of dynamic libraries, ignoring error messages that occur
+    # when we look at files that aren't actually libraries
+    for line in os.popen("readelf -d '%s' 2>/dev/null" % binary):

[kmixter1, 2010/03/01 23:37:33]

Do you need to explicitly close the os.popen pipe?  I'm not sure but leaking a
resource on every call could cause trouble in the future if we add more execs to
check.

+
+      # Grab dependencies
+      m = SHARED_RE.search(line)
+      if m:
+        libs.append(m.group(1))
+
+      # Add RPATHs in our search path
+      m = RPATH_RE.search(line)
+      if m:
+        paths = [os.path.join(self.root, path[1:])
+                 for path in m.group(1).split(":")]
+
+        self._ReadLibs(paths, libcache)
+
+    return libs
+
+  def CheckDependencies(self, binary):
+    """Check whether the libs for BINARY can be found in our sysroot."""
+
+    good = True
+
+    libcache = self.system_libcache.copy()
+    for lib in self._ReadDependencies(binary, libcache):
+      if lib[0] != "/":
+        if lib in libcache:
+          if self.verbose: print "Found %s" % lib
+        else:
+          print >>sys.stderr, "Problem with %s: Can't find %s" % (binary, lib)
+          good = False
+      else:
+        full_path = os.path.join(self.root, lib[1:])
+        if os.path.exists(full_path):
+          if self.verbose: print "Found %s" % lib
+        else:
+          print >>sys.stderr, "Problem with %s: Can't find %s" % (binary, lib)
+          good = False
+
+    return good
+
+
+def main():
+

[kmixter1, 2010/03/01 23:37:33]

please remove extra line

+  if len(sys.argv) < 3:
+    print "Usage: %s [-v] sysroot binary [ binary ... ]" % sys.argv[0]
+    sys.exit(1)
+
+  verbose = False
+  if sys.argv[1] == "-v":

[kmixter1, 2010/03/01 23:37:33]

one more parameter and you'll want to use getopt, but for now it's ok.

+    verbose = True
+    sys.argv = sys.argv[0:1] + sys.argv[2:]
+
+  checker = CheckDependencies(sys.argv[1], verbose)
+  errors = False
+  for binary in sys.argv[2:]:
+    if verbose: print "Checking %s" % binary
+    if not checker.CheckDependencies(binary):
+      errors = True
+
+  if errors:
+    sys.exit(1)
+  else:
+    sys.exit(0)
+
+if __name__ == "__main__":
+  main()