...and remove it from `PointeeInfo`, which isn't meant for this.
There are still various places (marked with FIXMEs) that assume all pointers
have the same size and alignment. Fixing this requires parsing non-default
address spaces in the data layout string, which will be done in a followup.
Pass 128-bit C-style enum enumerator values to LLVM
Pass the full 128 bits of C-style enum enumerators through to LLVM. This means that debuginfo for C-style repr128 enums is now emitted correctly for DWARF platforms (as compared to not being correctly emitted on any platform).
Tracking issue: #56071
DWARF version 5 brings a number of improvements over version 4. Quoting from
the announcement [1]:
> Version 5 incorporates improvements in many areas: better data compression,
> separation of debugging data from executable files, improved description of
> macros and source files, faster searching for symbols, improved debugging
> optimized code, as well as numerous improvements in functionality and
> performance.
On platforms where DWARF version 5 is supported (Linux, primarily), this commit
adds support for it behind a new `-Z dwarf-version=5` flag.
[1]: https://dwarfstd.org/Public_Review.php
This adds the typeid and `vcall_visibility` metadata to vtables when the
-Cvirtual-function-elimination flag is set.
The typeid is generated in the same way as for the
`llvm.type.checked.load` intrinsic from the trait_ref.
The offset that is added to the typeid is always 0. This is because LLVM
assumes that vtables are constructed according to the definition in the
Itanium ABI. This includes an "address point" of the vtable. In C++ this
is the offset in the vtable where information for RTTI is placed. Since
there is no RTTI information in Rust's vtables, this "address point" is
always 0. This "address point" in combination with the offset passed to
the `llvm.type.checked.load` intrinsic determines the final function
that should be loaded from the vtable in the
`WholeProgramDevirtualization` pass in LLVM. That's why the
`llvm.type.checked.load` intrinsics are generated with the typeid of the
trait, rather than with that of the function that is called. This
matches what `clang` does for C++.
The vcall_visibility metadata depends on three factors:
1. LTO level: Currently this is always fat LTO, because LLVM only
supports this optimization with fat LTO.
2. Visibility of the trait: If the trait is publicly visible, VFE
can only act on its vtables after linking.
3. Number of CGUs: if there is more than one CGU, also vtables with
restricted visibility could be seen outside of the CGU, so VFE can
only act on them after linking.
To reflect this, there are three visibility levels: Public, LinkageUnit,
and TranslationUnit.
In DWARF, alignment of types is specified in bits, as is made clear by the
parameter name `AlignInBits`. However, `rustc` was incorrectly passing a byte
alignment. This commit fixes that.
This was noticed in upstream LLVM when I tried to check in a test consisting of
LLVM IR generated from `rustc` and it triggered assertions [1].
[1]: https://reviews.llvm.org/D126835
Ensure all error checking for `#[debugger_visualizer]` is done up front and not when the `debugger_visualizer` query is run.
Clean up potential ODR violations when embedding pretty printers into the `__rustc_debug_gdb_scripts_section__` section.
Respond to PR comments and update documentation.
Begin fixing all the broken doctests in `compiler/`
Begins to fix#95994.
All of them pass now but 24 of them I've marked with `ignore HELP (<explanation>)` (asking for help) as I'm unsure how to get them to work / if we should leave them as they are.
There are also a few that I marked `ignore` that could maybe be made to work but seem less important.
Each `ignore` has a rough "reason" for ignoring after it parentheses, with
- `(pseudo-rust)` meaning "mostly rust-like but contains foreign syntax"
- `(illustrative)` a somewhat catchall for either a fragment of rust that doesn't stand on its own (like a lone type), or abbreviated rust with ellipses and undeclared types that would get too cluttered if made compile-worthy.
- `(not-rust)` stuff that isn't rust but benefits from the syntax highlighting, like MIR.
- `(internal)` uses `rustc_*` code which would be difficult to make work with the testing setup.
Those reason notes are a bit inconsistently applied and messy though. If that's important I can go through them again and try a more principled approach. When I run `rg '```ignore \(' .` on the repo, there look to be lots of different conventions other people have used for this sort of thing. I could try unifying them all if that would be helpful.
I'm not sure if there was a better existing way to do this but I wrote my own script to help me run all the doctests and wade through the output. If that would be useful to anyone else, I put it here: https://github.com/Elliot-Roberts/rust_doctest_fixing_tool
Only crate root def-ids don't have a parent, and in majority of cases the argument of `DefIdTree::parent` cannot be a crate root.
So we now panic by default in `parent` and introduce a new non-panicing function `opt_parent` for cases where the argument can be a crate root.
Same applies to `local_parent`/`opt_local_parent`.
Skip needless bitset for debuginfo
Found this while digging around looking at the inlining logic.
Seemed obvious enough so I decided to try to take care of it.
Is this what you had in mind, `@eddyb?`
Before this fix, the debuginfo for the fields was generated from the
struct defintion of Box<T>, but (at least at the moment) the compiler
pretends that Box<T> is just a (fat) pointer, so the fields need to be
`pointer` and `vtable` instead of `__0: Unique<T>` and `__1: Allocator`.
This is meant as a temporary mitigation until we can make sure that
simply treating Box as a regular struct in debuginfo does not cause too
much breakage in the ecosystem.
