view scripts/showasm @ 1613:96aa7ec74936 draft

Fix yet another sed bug. The s/// command would copy the \ of substitutions before deciding what to do with them (generally overwriting the \ with the new data). When the substitution was A) at the very end of the new string, B) resolved to nothing, it could leave a trailing \ that didn't belong there and didn't get overwritten because the "copy trailing data" part that copies the original string's null terminator already happened before the \ overwrote it. The ghostwheel() function restarts regexes after embedded NUL bytes, but if the string it's passed is _longer_ than the length it's told then it gets confused (and it means we're off the end of our allocation so segfaults are likely). Fix: test for \ first and move the "copy byte" logic into an else case.
author Rob Landley <>
date Mon, 15 Dec 2014 03:34:55 -0600
parents a43bdc6f53af
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# Copyright 2006 Rob Landley <>

# Dumb little utility function to print out the assembly dump of a single
# function, or list the functions so dumpable in an executable.  You'd think
# there would be a way to get objdump to do this, but I can't find it.

[ $# -lt 1 ] || [ $# -gt 2 ] && { echo "usage: showasm file function"; exit 1; }

[ ! -f $1 ] && { echo "File $1 not found"; exit 1; }

if [ $# -eq 1 ]
  objdump -d $1 | sed -n -e 's/^[0-9a-fA-F]* <\(.*\)>:$/\1/p'
  exit 0

objdump -d $1 | sed -n -e '/./{H;$!d}' -e "x;/^.[0-9a-fA-F]* <$2>:/p"