This required a thorough audit of every syscall wrapper in std.os.linux, so
while I was here, I fixed some minor arch-specific bugs, improved some types,
simplified some casts, and deleted some dead code.
Note that lseek() in particular is still broken for n32 and x32 after this
commit; this wrapper will require some special-casing in the arch bits due to
its unusual return type width.
closes https://github.com/ziglang/zig/issues/22464
closes https://codeberg.org/ziglang/zig/issues/31597
...but not in the way you'd expect. We were actually tracking them in
cases where we shouldn't have been! We cannot track a declaration if its
parent namespace has been lost, because that will cause analysis
failures immediately, but if we excluded a type from the mapping due to
a major change (such as a struct turning into a union, or a field being
added), we were still including any trackable instructions inside the
container's field expressions (e.g. struct field type expressions). This
meant we were tracking a type declaration while losing tracking on its
parent namespace, with predictably disastrous results.
Oh, also, tracking for opaque types was just totally wrong (I think this
was a typo from a while back). We could map it to things other than
opaque declarations, and we never mapped declarations inside opaques.
So, uh, I fixed that too.
The intention behind the iterator was to avoid needing to allocate the
symbols, but in practice we need to allocate them anyway since we need
to reverse their order and don't have random access. The alternative
would be an N^2 algorithm.
In practice this isn't that bad, because even if the allocation fails,
we'll still end up printing the address, so the user still ends up with
the necessary information to reconstruct the crash. I don't think it's
worth it to try to set up some kind of ring buffer or return partial
results on failure, but may revisit this.
This fix reveals another bug--we need to display the inline site syms in
the reverse of the encoded order. The parent/child relationships are
actually encoded on the inline sites, but it's likely a bit fragile to
try to trace those, and also more complex. As long as there aren't
multiple matches this is fine, and if there are, tracing the parent/child
chain won't work anyway.
This will be relevant once #31605 is merged.
In general, stack traces do *not* contain unique addresses for inlined
frames, but for error return traces, they will after the above PR. This
bool indicates that code printing the trace should not try to resolve
inline frames since they're explicitly encoded into the instruction
addresses.
This is set as state on stack trace rather than passed into the
formatting methods as an argument, as it's not really a formatting
option--whether or not it's correct to resolve inlines is decided at the
time of capture!
Alex Rønne Petersen