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label_funcs_with_no_xrefs.py
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label_funcs_with_no_xrefs.py
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##############################################################################################
# Copyright 2017 The Johns Hopkins University Applied Physics Laboratory LLC
# All rights reserved.
# Permission is hereby granted, free of charge, to any person obtaining a copy of this
# software and associated documentation files (the "Software"), to deal in the Software
# without restriction, including without limitation the rights to use, copy, modify,
# merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
# PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
# OR OTHER DEALINGS IN THE SOFTWARE.
##############################################################################################
# label_funcs_with_no_xrefs.py
# This script checks each defined function in the address range entered for cross-references.
# If there are no cross-references to the function, the prefix "noXrefs_" is added to the
# function's name. It then iterates through all functions in the code range again to identify
# all functions who's only code references are functions that have no cross-references. This
# is to detected functions called only by other functions who have no code references.
# This script helps to detect "dead code" that is never called.
#
# Inputs: start_addr: Start address for segment to define as data
# end_addr: End address for segment to define as data
# ignore_addrs: Addresses of functions that should not be considered as "noXref"
# For Example, RESET should be listed here
#
##############################################################################################
################### USER DEFINED VALUES ###################
# Function Addresses that should not be considered "No Crossreferences/Dead"
# For example, the reset and interrupt vectors don't have cross-references but should
# not be labeled as such.
ignore_addrs = (0x0, 0x8, 0x18)
###########################################################
def addPrefixToFunctionName(prefix, functionAddr):
name = GetFunctionName(curr_addr)
if (name and not name.startswith(prefix)):
name = prefix + name
print ("[label_funcs_with_no_xrefs.py] Function 0x%x Name: " % curr_addr) + name
MakeName(curr_addr, name)
start_addr = AskAddr(MinEA(), "Please enter the starting address for the functions to be examined.")
end_addr = AskAddr(MaxEA(), "Please enter the ending address for the functions to be examined.")
if ((start_addr is not None and end_addr is not None) and (start_addr != BADADDR and end_addr != BADADDR) and start_addr < end_addr):
print "[label_funcs_with_no_xrefs.py] Running on addresses 0x%x to 0x%x" % (start_addr, end_addr)
# If start_addr is in a function, get the starting address of that function. Else, returns -1.
curr_addr = GetFunctionAttr(start_addr, FUNCATTR_START) # Get the function head for the "start" addr
if (curr_addr == BADADDR):
# start_addr is not currently in a function so select the beginning of the next function
curr_addr = NextFunction(start_addr)
# Using this to continually iterate through all functions until no new functions
# having no code reference paths are found.
new_noXrefs_found = False
while (curr_addr != BADADDR and curr_addr < end_addr):
if (curr_addr not in ignore_addrs and (not GetFunctionName(curr_addr).startswith("noXrefs_"))):
xrefs = XrefsTo(curr_addr)
has_valid_xref = False;
for x in xrefs:
if (not GetFunctionName(x.frm).startswith("noXrefs_")):
# Function has a valid cross-reference and is not "dead code"
has_valid_xref = True;
break;
if (has_valid_xref == False):
# No valid xrefs were found to this function
new_noXrefs_found = True
addPrefixToFunctionName("noXrefs_", curr_addr)
curr_addr = NextFunction(curr_addr)
if ((curr_addr == BADADDR or curr_addr >= end_addr) and new_noXrefs_found):
print "[label_funcs_with_no_xrefs.py] Iterating through range again because new functions with no Xrefs found."
curr_addr = start_addr
new_noXrefs_found = False
curr_addr = NextFunction(curr_addr)
print "[label_funcs_with_no_xrefs.py] FINISHED."
else:
print "[label_funcs_with_no_xrefs.py] QUITTING. Invalid address(es) entered."