In vm/compaction.cpp I rescoped some variables to lower the stack usage
from 592 to 560 bytes. I wasn't very successful with this. The stack
usage is larger than it looks because methods on the structures used
take an implicit this pointer and a reference to the data (so the data
has to live out it's full scope and can't be put in a register).
In vm/debug.cpp I made a large (1024 bytes) stack allocated buffer
simply dynamically allocated.
In vm/os-unix.cpp I rescoped signal handling structures to not coincide
with each other and reduced a very large (1024 bytes) amount of stack
usage to less than 500 bytes.
clang-format doesn't recognize casts to non-pointer/non-template types
so it winds up adding a space between the right paren and the expression
and then failing to recognize prefix operators in the process
(e.g. foo = (cell) & bar; should be foo = (cell)&bar;). This commit
manually fixes up the major cases (fixnum, cell, all types ending in _t).
Don't update the map until the very last thing, and pass untranslated addresses to the iterator functors. Somewhat complicated by the fact that, for startup_fixup, the map is initialized with fixed-up values, so the fixup functor needs a flag indicating whether it operates with a fixed or unfixed code heap map.
Factor is finally a real C++ project and has a custom assert macro. Assertion failures were still getting caught as exceptions and causing failure loops. Write our own macro that calls factor::abort on failure.
* Clear faulting_p from a safepoint rather than inside general_error, because jumping into unwind-native-frames could blow up.
* Handle multiple faults from fatal_error by breakpointing. Is there anything else we can safely do at that point?
* Verify memory protection faults in the top half of the signal handlers because signal dispatch could fault. Treat memory faults during gc or fep as fatal errors.
* Add a function factor_vm::abort() that restores the default SIGABRT handler and ::abort()s. Use it from fatal_error() so we get useful context from gdb and so the user gets feedback from the system crash reporter that Factor blew up and didn't just disappear.
* In factorbug(), don't proceed with .s .r .c if it would be unsafe to do so.
* Don't pile on signals if we've already called fatal_error().
The stdin_loop thread will keep trying to consume input unless we stop it by sending it a signal. Use SIGUSR2 to stop the read syscall and a mutex to hold up the loop while the fep is active.
Also change the docs around so the useful commands are all listed under "Basic commands", and rename the more arcane "s" and "r" dumps to "ds" and "dr".
Also rename "q" to "c" because it "c"ontinues, remove the useless "im" command, and rename the less useful "t" to "trim" so we can use "t" to mean "throw"
It's not robust currently to raise an exception because a lot of our code that isn't already written with exceptions in mind breaks. Also, a signal is likely to be received by an FFI callback installed on the IO multiplexer, which will cause Factor to die since the callback cannot handle the exception. We need a more robust solution to dealing with SIGINT.
Also lay some groundwork for counting profile samples and reporting non-interrupting asynchronous signals.
- change some primitives into sub-primitives: fixnum+ fixnum- fixnum* inline-cache-miss inline-cache-miss-tail
- rename some relocation types for clarity
- some other minor re-organizations and cleanups
Björn Lindqvist
Steven Stewart-Gallus
Erik Charlebois
Joe Groff
Slava Pestov
Doug Coleman