The goal was to improve readability, but along the way a few things were
gained.
- Sorted sym and map files
- Infrastructure for supporting multiple .o versions
- Valgrind-proof, as far as my testing goes anyways
- Improved verbosity messages
- Added error checking
- Performance improvements, see end of commit message
The readability improvement was spurred while trying to make sense of the
old code while trying to implement features such as sorted sym and map
files.
I also did my best to remove hardcoded logic, such that modifications
should be doable; for example, "RAM loading" sections, which are linked
against a different location than the one they're stored at.
Some work remains to be done, see the "TODO:" and "FIXME:" comments.
Further, while regression tests pass, this new linker should be tested on
different codebases (ideally while instrumented with `make develop` and
under valgrind).
The few errors spotted in the man pages (alignment) need to be corrected.
Finally, documentation comments need to be written, I have written a lot of
them but not all.
This also provides a significant performance boost (benchmarked with a
51994-symbol project):
Current master RGBLINK:
2.02user 0.03system 0:02.06elapsed 99%CPU (0avgtext+0avgdata 84336maxresident)k
0inputs+11584outputs (0major+20729minor)pagefaults 0swaps
Rewritten RGBLINK:
0.19user 0.06system 0:00.63elapsed 40%CPU (0avgtext+0avgdata 32460maxresident)k
23784inputs+11576outputs (0major+7672minor)pagefaults 0swaps
The stdlib functions specify the difference between `err` and `errx`
is that the former prints a message obtained with `strerror`.
However, RGBDS' implementation breaks that contract, and `warn`'s puts the
added semicolon in the wrong place.
This is especially useful when an EQUS expands to another one, to help
track them.
This is done separately from the file stack as the EQUS stack is separate
(which is itself because EQUS are managed *way* differently).
Macro and rept buffers were not always being terminated with newlines
and/or were vulnerable to the final newline being escaped, allowing
buffer overflows to occur. Now, they are terminated with newlines using
the same mechanism as the file buffer.
Null characters in the middle of strings interact badly with the RGBDS
codebase, which assumes null-terminated strings. There is no reason to
support null characters in input source code, so the simplest way to deal
with null characters is to reject them early.
They do not take any room, so they can only be used to define symbols at
a given location. I ran into trouble with such a SECTION failing to be
placed where specified, which doesn't make sense.
This way, it also makes sense to have such a SECTION in the middle of
another one, but that should be fine, since there's no actual overlap.
f29d768 forgot to switch these two `expr->nVal` to `src1->nVal`
This won't break anything, since this wasn't published yet.
I checked, and didn't see any other missed changes.
Reported by pret, I confirmed that `1 && 1` evaluated to 0.
This is good for debugging Makefiles on systems I don't have (eg. macOS)
End users will not be affected by this, and CI provides a persistent log
so clobbering isn't much of an issue.
