Cleanups from post-submit suggestions.

Review URL: http://codereview.chromium.org/126062


git-svn-id: http://src.chromium.org/svn/trunk/src/build@18303 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

linux/dump_app_syms

@@ -10,7 +10,7 @@
 set -e
 
 usage() {
-  echo "$0 <dump_syms_exe> <binary_with_symbols> <symbols_output>"
+  echo "$0 <dump_syms_exe> <binary_with_symbols> <symbols_output>" >&2
 }
 
 
@@ -26,12 +26,14 @@ OUTFILE="$3"
 
 STRIPPED=$(mktemp -q -t stripped-XXXXX)
 if [ $? -ne 0 ]; then
-  echo "ERROR: Could not create temp stripped '$INFILE'"
+  echo "ERROR: Could not create temp stripped '$INFILE'" >&2
   exit 1
 fi
 
 # Dump the symbols from the given binary.
-"$DUMPSYMS" "$INFILE" > "$OUTFILE"
+if [ "$INFILE" -nt "$OUTFILE" ]; then
+  "$DUMPSYMS" "$INFILE" > "$OUTFILE"
+fi
 
 # Strip the binary and calculate the signature of that, since that's what ships.
 strip "$INFILE" -o "$STRIPPED"
@@ -39,6 +41,4 @@ NEWSIG=$("$SCRIPTDIR/dump_signature.py" "$STRIPPED")
 rm "$STRIPPED"
 
 # Replace the old signature with the stripped signature in the symbols file.
-INFILE_BASE=$(basename "$INFILE")
-sed -i "1s/[0-9A-F]* $INFILE_BASE/$NEWSIG $INFILE_BASE/" "$OUTFILE"
-
+sed -i "1s/ [0-9A-F]* / $NEWSIG /" "$OUTFILE"

linux/dump_signature.py

@@ -8,6 +8,7 @@
 # src/breakpad/linux/minidump_writer.cc@17081
 
 import sys
+import struct
 
 if len(sys.argv) != 2:
   sys.stderr.write("Error, no filename specified.\n")
@@ -17,15 +18,13 @@ bin = open(sys.argv[1])
 data = bin.read(4096)
 if len(data) != 4096:
   sys.stderr.write("Error, did not read first page of data.\n");
+  sys.exit(1)
 bin.close()
 
 signature = [0] * 16
 for i in range(0, 4096):
   signature[i % 16] ^= ord(data[i])
 
-out = ''
-# Assume we're running on little endian
-for i in [3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11, 12, 13, 14, 15]:
-  out += '%02X' % signature[i]
-out += '0'
+out = ('%08x%04x%04x%02x%02x%02x%02x%02x%02x%02x%02x0' %
+      struct.unpack('I2H8B', struct.pack('16B', *signature)))
 sys.stdout.write(out)