The option to dump source intermixed with with disassembly is –S
A useful tip for conveniently generating dump files is to create a batch file that invokes avr-objdump.exe and sends the output to a text file in the sketch directory. Here is a batch file that will do this, you need to rename the path to match the location of avr-dump.exe on your machine
rem: this batch will send avr-objdump output of the elf file given as the parameter to a file in that directory with .txt appended
rem: change the path below so its correct for the location of objdump.exe on your machine
C:\Arduino\arduino-0011\hardware\tools\avr\bin\avr-objdump.exe -S %1 > %1%.txt
If you are using windows, save the batch to a file called avr-objdump.bat in the sendto directory. (tip: from the start menu, click run and type sendto into the text box and click ok)
If the batch is in the sentdo directory then you can right click on an elf file in a sketch applet directory and the batch will create a dump file in that directory with the extension .txt
I hope you find that as useful as I have.