dwarves is a set of tools that use the DWARF debugging information
inserted in ELF binaries by compilers such as GCC, used by well known
debuggers such as GDB, and more recent ones such as systemtap.
Utilities in the dwarves suite include pahole, that can be used to
find alignment holes in structs and classes in languages such as C,
C++, but not limited to these.
It also extracts other information such as CPU cacheline alignment,
helping pack those structures to achieve more cache hits.
A diff like tool, codiff can be used to compare the effects changes
in source code generate on the resulting binaries.
Another tool is pfunct, that can be used to find all sorts of
information about functions, inlines, decisions made by the compiler
about inlining, etc.
The documentation about ctracer is not updated to the latest
developments: it now generates systemtap scripts, stay tuned for
improvements in this area!