Quick script for inserting debug statements in smali code.. Somewhat works!

debug-inserter.py

import os
import re

class debug_inserter(object):
    def __init__(self, path_to_files, prefix):
        self.path_to_files = path_to_files
        self.debug_prefix = prefix
        self.debug_statement = """const-string {0}, \"{1} - {2}\"
    invoke-static {{0}, {0}}, Landroid/util/Log;->d(Ljava/lang/String;Ljava/lang/String;)I"""
        self.re_filename = re.compile("\.smali$")
        self.re_method = re.compile("^\.method [a-z]+ ([^ ]+)")
        self.re_locals = re.compile("^\s+ \.locals (\d+)")
        #self.re_global = re.compile(r"(^\.method [a-z]+ ([^ ]+).*)\s+\.locals (\d)", re.MULTILINE)
        self.re_global = re.compile(r"(^\.method ?(public|private|protected)? ?(constructor|static|native)? ([^ \(]+).*)\s+\.locals (\d+)", re.MULTILINE)
    


    def read_files(self):
        for root, directories, filenames in os.walk(self.path_to_files):
            for filename in filenames:
                print("fixing filename - "+filename)
                self.fix_file(root+"/"+filename)

    def fix_file(self, file_name):
        f = open(file_name, "r")
        data = f.read()
        f.close()
        matches = self.re_global.search(data)
        if not matches:
            return
        #print(self.re_global.sub(r"\1 .locals \3+1", data))
        f = open(file_name, "w")
        f.write(self.re_global.sub(lambda m: test(m, file_name), data))
        f.close()

                
            
def test(match, file_name):
    debug_statement = """const-string v0, \"{1} - {2} - {3}\"
    invoke-static {{v0, v0}}, Landroid/util/Log;->d(Ljava/lang/String;Ljava/lang/String;)I"""
    method = match.group(1).strip()
    name = match.group(4).strip()
    local_count = match.group(5).strip()
    return method+"\n    .locals "+str(int(local_count)+0)+"\n    "+debug_statement.format(local_count, "realprefix", file_name, name)

x = debug_inserter("dk.bec.android.mb1.b00019.prod/smali/dk", "debugprefix")
x.read_files()