GNU Info
(nasm.info)Section 6.10
6.10. `dbg': Debugging Format
=============================
The `dbg' output format is not built into NASM in the default
configuration. If you are building your own NASM executable from the
sources, you can define `OF_DBG' in `outform.h' or on the compiler
command line, and obtain the `dbg' output format.
The `dbg' format does not output an object file as such; instead, it
outputs a text file which contains a complete list of all the
transactions between the main body of NASM and the output-format back
end module. It is primarily intended to aid people who want to write
their own output drivers, so that they can get a clearer idea of the
various requests the main program makes of the output driver, and in
what order they happen.
For simple files, one can easily use the `dbg' format like this:
nasm -f dbg filename.asm
which will generate a diagnostic file called `filename.dbg'. However,
this will not work well on files which were designed for a different
object format, because each object format defines its own macros
(usually user- level forms of directives), and those macros will not be
defined in the `dbg' format. Therefore it can be useful to run NASM
twice, in order to do the preprocessing with the native object format
selected:
nasm -e -f rdf -o rdfprog.i rdfprog.asm
nasm -a -f dbg rdfprog.i
This preprocesses `rdfprog.asm' into `rdfprog.i', keeping the `rdf'
object format selected in order to make sure RDF special directives are
converted into primitive form correctly. Then the preprocessed source
is fed through the `dbg' format to generate the final diagnostic output.
This workaround will still typically not work for programs intended
for `obj' format, because the `obj' `SEGMENT' and `GROUP' directives
have side effects of defining the segment and group names as symbols;
`dbg' will not do this, so the program will not assemble. You will have
to work around that by defining the symbols yourself (using `EXTERN',
for example) if you really need to get a `dbg' trace of an
`obj'-specific source file.
`dbg' accepts any section name and any directives at all, and logs
them all to its output file.
automatically generated by info2www version 1.2.2.9