- .eh_frame_hdr contains a binary-searchable data structure for finding an FDE. If present, we can use this
section to avoid having to parse the entire FDE/CIE list in the binary, instead only entries that are actually
required for unwinding are read.
- rework the inputs pc-relative pointer decoding to support both already-mapped sections as well as sections
mapped from a file
- store the VirtualMachine on UnwindContext so the allocations can be reused
Some distributions (ie. Ubuntu) have their libc debug
info in separate files. This change allows the stack walking
code to read that debug info.
- add support for reading compressed ELF sections
- support reading the build-id from the elf headers in order to lookup external debug info
- support reading the .gnu_debuglink section to look up external debug info
At the moment, the LLVM IR we generate for this fn is
define internal fastcc void @AstGen.numberLiteral ... {
Entry:
...
%16 = alloca %"fmt.parse_float.decimal.Decimal(f128)", align 8
...
That `Decimal` is huuuge! It stores
pub const max_digits = 11564;
digits: [max_digits]u8,
on the stack.
It comes from `convertSlow` function, which LLVM happily inlined,
despite it being the cold path. Forbid inlining that to not penalize
callers with excessive stack usage.
Backstory: I was looking for needles memcpys in TigerBeetle, and came up
with this copyhound.zig tool for doing just that:
ee67e2ab95/src/copyhound.zig
Got curious, run it on the Zig's own code base, and looked at some of
the worst offenders.
List of worst offenders:
warning: crypto.kyber_d00.Kyber.SecretKey.decaps: 7776 bytes memcpy
warning: crypto.ff.Modulus.powPublic: 8160 bytes memcpy
warning: AstGen.numberLiteral: 11584 bytes memcpy
warning: crypto.tls.Client.init__anon_133566: 13984 bytes memcpy
warning: http.Client.connectUnproxied: 16896 bytes memcpy
warning: crypto.tls.Client.init__anon_133566: 16904 bytes memcpy
warning: objcopy.ElfFileHelper.tryCompressSection: 32768 bytes memcpy
Note from Andrew: I removed `noinline` from this commit since it should
be enough to set it to be cold.
It is assumed that generating a collision requires more than 2^156
ciphertext modifications. This is plenty enough for any practical
purposes, but it hasn't been proven to be >= 2^256.
Be consistent and conservative here; just claim the same security
as the other variants.
* move inferred error sets into InternPool.
- they are now represented by pointing directly at the corresponding
function body value.
* inferred error set working memory is now in Sema and expires after
the Sema for the function corresponding to the inferred error set is
finished having its body analyzed.
* error sets use a InternPool.Index.Slice rather than an actual slice
to avoid lifetime issues.
The code removed does unnecessary copying in order to create a null-terminated pointer, just to pass it to libc getenv. It only does this for `small keys`, which are under 64 bytes in size.
Instead of going out of the way to add a null byte to a function that takes normal slices, this should just be handled by the loop below, which scans c.environ to find the value
And when we have the choice, favor little-endian because it's 2023.
Gives a slight performance improvement:
md5: 552 -> 555 MiB/s
sha1: 768 -> 786 MiB/s
sha512: 211 -> 217 MiB/s
* Small documentation fix of ChaCha variants
Previous documentation was seemingly copy-pasted and left
behind some errors where the number of rounds was not
properly updated.
* Suggest `std.crypto.utils.secureZero` on `@memset` docs
* Revert previous change
* autodoc: init work to refactor exprName
* autodoc: Implement more expressions in exprName refactor
* autodoc: more work
* autodoc: More exprName to ex refactoring
* autodoc: Remove whitespace flag from renderer; Add pre tags in
value and variable drawing in renderContainer
* autodoc: add inline styling to pre blocks
* autodoc: move renderer code to main.js
* autodoc: More exprName to ex refactoring; Fn signatures rendered with new code
* autodoc: Fix function rendering. Add more things to ex
* autodoc: nuke exprName
---------
Co-authored-by: Krzysztof Wolicki <der.teufel.mail@gmail.com>
