There are a variety of tools that can be used to analyze DF memory - some are listed here. Note that some of these may be old and unmaintained. If you aren’t sure what tool would be best for your purposes, feel free to ask for advice (on IRC, Bay12, etc.).
Ghidra is a cross-platform reverse-engineering framework (written in Java)
available at https://ghidra-sre.org. It supports analyzing both 32-bit and
64-bit executables for all supported DF platforms. There are some custom DFHack
Ghidra scripts available in the df_misc repo (look for
IDA Freeware 7.0¶
Available from Hex-Rays.
Supports analyzing both 32-bit and 64-bit executables for all supported DF platforms.
.idc scripts for IDA are available in the df_misc repo.
Runs on macOS and some Linux distributions; available from https://www.hopperapp.com/. TWBT uses this to produce some patches.
There are a few development plugins useful for low-level memory research. They
are not built by default, but can be built by setting the
CMake option. These include:
check-structures-sanity, which performs sanity checks on the given DF object. Note that this will crash in several cases, some intentional, so using this with GDB is recommended.
memview, which produces a hex dump of a given memory range. It also highlights valid pointers, and can be configured to work with Sizecheck to auto-detect object sizes.
vectors, which can identify instances of
std::vectorin a given memory range.
Several development tools can be useful for memory research. These include (but are not limited to):
Generally, any script starting with
Sizecheck is a custom tool that hooks into the memory allocator and inserts a header indicating the size of every object. The corresponding logic to check for this header when freeing memory usually works, but is inherently not foolproof. You should not count on DF being stable when using this.
DFHack’s implementation of sizecheck is currently only tested on Linux, although
it probably also works on macOS. It can be built with the
CMake option, which produces a
library installed in the
hack folder. On Linux, passing
--sc as the
first argument to the
dfhack launcher script will load this library on
startup. On other platforms, or when passing a different argument to the
launcher (such as for GDB), you will need to preload this library
manually, by setting
PRELOAD_LIB on Linux (or
LD_PRELOAD if editing the
dfhack launcher script directly), or by editing the
script and adding the library to
DYLD_INSERT_LIBRARIES on macOS.
There is also an older sizecheck implementation by Mifki available on
b.cpp is the main
sizecheck library, and
win_patch.cpp is used for Windows support). To use
this with other DFHack tools, you will likely need to edit the header’s
magic number to match what is used in devel/sc (search for a hexadecimal
constant starting with
Some very old DFHack tools are available in the legacy branch on GitHub. No attempt is made to support these.
GDB is technically cross-platform, but
tends to work best on Linux, and DFHack currently only offers support for using
GDB on 64-bit Linux. To start with GDB, pass
-g to the DFHack launcher
Some basic GDB commands:
run: starts DF from the GDB prompt. Any arguments will be passed as command-line arguments to DF (e.g. load-save may be useful).
btwill produce a backtrace if DF crashes.
See the official GDB documentation for more details.
Other analysis tools¶
dfhack launcher script on Linux has support for launching several other
tools alongside DFHack, including Valgrind (as well as Callgrind and Helgrind)
and strace. See the script for the exact command-line option to specify. Note
that currently only one tool at a time is supported, and must be specified
with the first argument to the script.
This is a tool written by Angavrilov and available on GitHub. It only supports 32-bit DF. Some assistance may be available on IRC.
EDB (Evan’s debugger)¶
Available on GitHub.
Some people have used Cheat Engine for research in the past.