JuliaLang/julia
Auf GitHub ansehenWhy do StackFrame comparisons and hash ignore linfo?
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#47.028 geöffnet am 3. Okt. 2022
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Beschreibung
We were seeing bugs in PProf's conversion from stack traces (Vector{StackFrame}) to PProf protos, and we eventually tracked the issue down to this:
Aha! It turns out it's because comparing StackFrames apparently skips the linfo and pointer, even though apparently also sometimes a StackFrame can be empty other than the linfo and pointer!!! 😮 https://github.com/JuliaLang/julia/blob/00646634c6a73998eaae3785eb78fea881c39502/base/stacktraces.jl#L80-L96
And indeed, in this case:
julia> fr1.func, fr1.line, fr1.file, fr1.inlined (Symbol(""), -1, Symbol(""), false) julia> fr3.func, fr3.line, fr3.file, fr3.inlined (Symbol(""), -1, Symbol(""), false)(I'm not sure why that stuff is all missing!?)
Originally posted by @NHDaly in https://github.com/JuliaPerf/PProf.jl/issues/69#issuecomment-1264461763
So, two questions, I guess:
- Do you know why it's possible for all the other fields of a StackTrace to be not present, even when it's not inlined?
- Given that the above is possible, why do we ignore the linfo for the hash and == comparisons? Is it a perf optimization?
- and follow-up: what about the
.pointerfield?
- and follow-up: what about the
thanks!