#! /usr/bin/env python

# objgraph
#
# Read "nm -o" input (on IRIX: "nm -Bo") of a set of libraries or modules
# and print various interesting listings, such as:
#
# - which names are used but not defined in the set (and used where),
# - which names are defined in the set (and where),
# - which modules use which other modules,
# - which modules are used by which other modules.
#
# Usage: objgraph [-cdu] [file] ...
# -c: print callers per objectfile
# -d: print callees per objectfile
# -u: print usage of undefined symbols
# If none of -cdu is specified, all are assumed.
# Use "nm -o" to generate the input (on IRIX: "nm -Bo"),
# e.g.: nm -o /lib/libc.a | objgraph


import sys
import os
import getopt
import re

# Types of symbols.
#
definitions = 'TRGDSBAEC'
externals = 'UV'
ignore = 'Nntrgdsbavuc'

# Regular expression to parse "nm -o" output.
#
matcher = re.compile('(.*):\t?........ (.) (.*)$')

# Store "item" in "dict" under "key".
# The dictionary maps keys to lists of items.
# If there is no list for the key yet, it is created.
#
def store(dict, key, item):
   if dict.has_key(key):
       dict[key].append(item)
   else:
       dict[key] = [item]

# Return a flattened version of a list of strings: the concatenation
# of its elements with intervening spaces.
#
def flat(list):
   s = ''
   for item in list:
       s = s + ' ' + item
   return s[1:]

# Global variables mapping defined/undefined names to files and back.
#
file2undef = {}
def2file = {}
file2def = {}
undef2file = {}

# Read one input file and merge the data into the tables.
# Argument is an open file.
#
def readinput(fp):
   while 1:
       s = fp.readline()
       if not s:
           break
       # If you get any output from this line,
       # it is probably caused by an unexpected input line:
       if matcher.search(s) < 0: s; continue # Shouldn't happen
       (ra, rb), (r1a, r1b), (r2a, r2b), (r3a, r3b) = matcher.regs[:4]
       fn, name, type = s[r1a:r1b], s[r3a:r3b], s[r2a:r2b]
       if type in definitions:
           store(def2file, name, fn)
           store(file2def, fn, name)
       elif type in externals:
           store(file2undef, fn, name)
           store(undef2file, name, fn)
       elif not type in ignore:
           print fn + ':' + name + ': unknown type ' + type

# Print all names that were undefined in some module and where they are
# defined.
#
def printcallee():
   flist = file2undef.keys()
   flist.sort()
   for filename in flist:
       print filename + ':'
       elist = file2undef[filename]
       elist.sort()
       for ext in elist:
           if len(ext) >= 8:
               tabs = '\t'
           else:
               tabs = '\t\t'
           if not def2file.has_key(ext):
               print '\t' + ext + tabs + ' *undefined'
           else:
               print '\t' + ext + tabs + flat(def2file[ext])

# Print for each module the names of the other modules that use it.
#
def printcaller():
   files = file2def.keys()
   files.sort()
   for filename in files:
       callers = []
       for label in file2def[filename]:
           if undef2file.has_key(label):
               callers = callers + undef2file[label]
       if callers:
           callers.sort()
           print filename + ':'
           lastfn = ''
           for fn in callers:
               if fn <> lastfn:
                   print '\t' + fn
               lastfn = fn
       else:
           print filename + ': unused'

# Print undefined names and where they are used.
#
def printundef():
   undefs = {}
   for filename in file2undef.keys():
       for ext in file2undef[filename]:
           if not def2file.has_key(ext):
               store(undefs, ext, filename)
   elist = undefs.keys()
   elist.sort()
   for ext in elist:
       print ext + ':'
       flist = undefs[ext]
       flist.sort()
       for filename in flist:
           print '\t' + filename

# Print warning messages about names defined in more than one file.
#
def warndups():
   savestdout = sys.stdout
   sys.stdout = sys.stderr
   names = def2file.keys()
   names.sort()
   for name in names:
       if len(def2file[name]) > 1:
           print 'warning:', name, 'multiply defined:',
           print flat(def2file[name])
   sys.stdout = savestdout

# Main program
#
def main():
   try:
       optlist, args = getopt.getopt(sys.argv[1:], 'cdu')
   except getopt.error:
       sys.stdout = sys.stderr
       print 'Usage:', os.path.basename(sys.argv[0]),
       print           '[-cdu] [file] ...'
       print '-c: print callers per objectfile'
       print '-d: print callees per objectfile'
       print '-u: print usage of undefined symbols'
       print 'If none of -cdu is specified, all are assumed.'
       print 'Use "nm -o" to generate the input (on IRIX: "nm -Bo"),'
       print 'e.g.: nm -o /lib/libc.a | objgraph'
       return 1
   optu = optc = optd = 0
   for opt, void in optlist:
       if opt == '-u':
           optu = 1
       elif opt == '-c':
           optc = 1
       elif opt == '-d':
           optd = 1
   if optu == optc == optd == 0:
       optu = optc = optd = 1
   if not args:
       args = ['-']
   for filename in args:
       if filename == '-':
           readinput(sys.stdin)
       else:
           readinput(open(filename, 'r'))
   #
   warndups()
   #
   more = (optu + optc + optd > 1)
   if optd:
       if more:
           print '---------------All callees------------------'
       printcallee()
   if optu:
       if more:
           print '---------------Undefined callees------------'
       printundef()
   if optc:
       if more:
           print '---------------All Callers------------------'
       printcaller()
   return 0

# Call the main program.
# Use its return value as exit status.
# Catch interrupts to avoid stack trace.
#
if __name__ == '__main__':
   try:
       sys.exit(main())
   except KeyboardInterrupt:
       sys.exit(1)