std: Enable usage of `thread_local!` through imports
The `thread_local!` macro delegated to an internal macro but it didn't
do so in a macros-and-the-module-system compatible fashion, meaning if a
`#![no_std]` crate imported `std` and tried to use `thread_local!` it
would fail due to missing a lookup of an internal macro.
This commit switches the macro to instead use `$crate` to invoke other
macros, ensuring that it'll work when `thread_local!` is imported alone.
std: Improve codegen size of accessing TLS
Some code in the TLS implementation in libstd stores `Some(val)` into an
`&mut Option<T>` (effectively) and then pulls out `&T`, but it currently
uses `.unwrap()` which can codegen into a panic even though it can never
panic. With sufficient optimizations enabled (like LTO) the compiler can
see through this but this commit helps it along in normal mode
(`--release` with Cargo by default) to avoid codegen'ing the panic path.
This ends up improving the optimized codegen on wasm by ensuring that a
call to panic pulling in more file size doesn't stick around.
Use lld directly for Fuchsia target
Fuchsia already uses lld as the default linker, so there's no reason
to always invoke it through Clang, instead we can simply invoke lld
directly and pass the set of flags that matches Clang.
Fuchsia already uses lld as the default linker, so there's no reason
to always invoke it through Clang, instead we can simply invoke lld
directly and pass the set of flags that matches Clang.
It is necessary to detect whether we are making the first
assignment into a union. This is checked by looking at the moves and
checking if there are any from locations earlier in the control flow
graph.
This commit improves the detection of this by switching from a naive
method that compared only the statement and basic block indices with
a more robust method that looks at the predecessors of a location.
This commit adds a run-pass test for the subset of
`src/test/ui/borrowck/borrowck-union-move-assign.rs` that is intended to
pass as the union is reinitialized.
Bug #55606 points out a regression introduced by #54004; namely that
an assertion can erroneously fire when a niche-filling discriminant
value is emitted.
This fixes the bug by removing the assertion, and furthermore by
arranging for the discriminant value to be masked according to the
size of the niche. This makes handling the discriminant a bit simpler
for debuggers.
The test case is from Jonathan Turner.
Closes#55606
NLL has increased precision in its analysis of drop order, and we want
the test annotations to deliberately reflect this by having fewer
ERROR annotations for NLL than for AST-borrowck. The best way to get
this effect is via `// revisions`.
As a drive-by, also added uses of all the borrows just to make it
clear that NLL isn't somehow sidestepping things by using shorter
borrows than you might have otherwise expected. (Of course, the added
uses do not make all that much difference since the relevant types all
declare `impl Drop` and thus those drops have implicit uses anyway.)
This is a variant of `ui/borrowck/borrowck-closures-mut-of-imm.rs`
that I used to help identify what changes I needed to make to the
latter file in order to recover its instances of E0524 under NLL.
(Basically this test includes the changes you'd need to make to
`ui/borrowck/borrowck-closures-mut-of-imm.rs` in order to get rid of
occurrences of E0596. And then I realized that one needs to add
invocations of the closures in order to properly extend the mutable
reborrows in a manner such that NLL will roughly match AST-borrowck.)
This is based on the feedback from estebank:
"""
I believe that test can be removed outright. It'd be impossible for a
new change to go through that breaks this kind of output without it
being picked up by multiple other `stderr` tests. This is an artifact
of the transition period to the "new" output style.
"""
see: https://github.com/rust-lang/rust/issues/52663#issuecomment-422155551
This is not strictly necessary to make this test "more robust with
respect to NLL"; its just an attempt to narrow the scope of the test
and focus on its core.
Most of the time we want to robustify tests, but in this case this
test is deliberately encoding artifacts of AST-borrowck. So instead
of adding artificial uses that would obscure the aspects of
AST-borrowck that are being tests, we instead use revisions and then
mark the cases that apply to NLL as well as AST-borrowck.
rustdoc: refactor: centralize all command-line argument parsing
This is something i've wanted to do for a while, since we keep having to add new arguments to places like `rust_input` or `core::run_core` whenever we add a new CLI flag or the like. Those functions have inflated up to 11-19, and in some cases hiding away the locations where some CLI flags were being parsed, obscuring their use. Now, we have a central place where all command-line configuration occurs, including argument validation.
One note about the design: i grouped together all the arguments that `html::render::run` needed, so that i could pass them on from compilation in one lump instead of trying to thread through individual items or clone the entire blob ahead of time.
One other thing this adds is that rustdoc also now recognizes all the `-Z` options that rustc does, since we were manually grabbing a few previously. Now we parse a full `DebuggingOptions` struct and hand it directly to rustc when scraping docs.
