Fix parse_elfnote.py.

The first column of readelf -S output can be split into multiple items
by `split`:

  [ 8] .note.android.ide NOTE            00000000 0000ec 000098 00   A  0   0  4
  [ 9] .comment          PROGBITS        00000000 000184 000028 01  MS  0   0  1
  [10] .rel.text         REL             00000000 0001ac 000048 08   I 13   1  4
  [11] .note.GNU-stack   PROGBITS        00000000 0001f4 000000 00      0   0  0

Skip until past the first closing bracket since we don't care about
the index anyway.

Also called readelf with -W to get wide output. Addresses for 64-bit
binaries were large enough to cause the data to be displayed across
two rows.

Bug: None
Test: ran parse_elfnote.py
Change-Id: Ica8cc5f232ebe333137f324c07979bfe7f6e1e1c

1 files changed, 47 insertions, 11 deletions

diff --git a/parse_elfnote.py b/parse_elfnote.py
index a5aae1a11..5f84b72a7 100644
--- a/parse_elfnote.py
+++ b/parse_elfnote.py
@@ -16,17 +16,23 @@
 #
 
 import argparse
+import logging
 import subprocess
 import sys
 from ctypes import c_char
 from ctypes import c_int
 from ctypes import Structure
 
-SEC_NAME = '.note.android.ide'
+SEC_NAME = '.note.android.ident'
 ABI_VENDOR = 'Android'
 NDK_RESERVED_SIZE = 64
 
 
+def logger():
+    """Returns the module logger."""
+    return logging.getLogger(__name__)
+
+
 class AbiTag(Structure):
     _fields_ = [('namesz', c_int),
                 ('descsz', c_int),
@@ -39,17 +45,32 @@ class AbiTag(Structure):
 
 # Get the offset to a section from the output of readelf
 def get_section_pos(sec_name, file_path):
-    cmd = ['readelf', '--sections', file_path]
+    cmd = ['readelf', '--sections', '-W', file_path]
     output = subprocess.check_output(cmd)
     lines = output.split('\n')
     for line in lines:
-        if sec_name in line:
-            sections = line.split()
-            if len(sections) < 6 or sec_name not in sections[1]:
-                sys.exit('Failed to get offset of {}'.format(sec_name))
-            addr = int(sections[3], 16)
-            off = int(sections[4], 16)
-            return addr + off
+        logger().debug('Checking line for "%s": %s', sec_name, line)
+        # Looking for a line like the following (all whitespace of unknown
+        # width).
+        #
+        #   [ 8] .note.android.ident NOTE 00000000 0000ec 000098 00 A 0 0 4
+        #
+        # The only column that might have internal whitespace is the first one.
+        # Since we don't care about it, remove the head of the string until the
+        # closing bracket, then split.
+        if sec_name not in line:
+            continue
+        if ']' not in line:
+            continue
+        line = line[line.index(']') + 1:].strip()
+
+        sections = line.split()
+        if len(sections) < 5 or sec_name not in sections[0]:
+            logger().debug('Did not find "%s" in %s', sec_name, sections[0])
+            sys.exit('Failed to get offset of {}'.format(sec_name))
+        addr = int(sections[2], 16)
+        off = int(sections[3], 16)
+        return addr + off
     sys.exit('Failed to find section: {}'.format(sec_name))
 
 
@@ -62,11 +83,26 @@ def print_info(tag):
     print 'ABI_NDK_BUILD_NUMBER: {}'.format(tag.ndk_build_number)
 
 
-def main():
+def parse_args():
+    """Parses command line arguments."""
     parser = argparse.ArgumentParser()
     parser.add_argument('file_path',
                         help="path of the ELF file with embedded ABI tags")
-    args = parser.parse_args()
+    parser.add_argument(
+        '-v', '--verbose', dest='verbosity', action='count', default=0,
+        help='Increase logging verbosity.')
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+    if args.verbosity == 1:
+        logging.basicConfig(level=logging.INFO)
+    elif args.verbosity >= 2:
+        logging.basicConfig(level=logging.DEBUG)
+    else:
+        logging.basicConfig()
+
     file_path = args.file_path
 
     with open(file_path, "rb") as obj_file: