rustc: Set release mode cgus to 16 by default
This commit is the next attempt to enable multiple codegen units by default in
release mode, getting some of those sweet, sweet parallelism wins by running
codegen in parallel. Performance should not be lost due to ThinLTO being on by
default as well.
Closes#45320
Set the dwarf linkage_name to the mangled name
ref #46453
@michaelwoerister or anyone else who knows, i'm not sure if this is the correct instance to pass here (or how to get the correct one precisely): 5a94a48678/src/librustc_trans/debuginfo/namespace.rs (L36)
So don't merge this yet, I'd like to learn about correct instance first; however, I think this already fixes a bunch of weirdness i'm seeing debugging from time to time, not to mention backtraces in gdb via `bt` are now ~readable~ meaningful 🎉
E.g.:
new:
```
(gdb) bt
#0 <inline::Foo as core::convert::From<()>>::from () at /home/m4b/tmp/bad_debug/inline.rs:11
#1 0x000055555555a35d in inline::deadbeef () at /home/m4b/tmp/bad_debug/inline.rs:16
#2 0x000055555555a380 in inline::main () at /home/m4b/tmp/bad_debug/inline.rs:20
```
old:
```
(gdb) bt
#0 inline::{{impl}}::from () at /home/m4b/tmp/bad_debug/inline.rs:11
#1 0x000055555555b0ed in inline::deadbeef () at /home/m4b/tmp/bad_debug/inline.rs:16
#2 0x000055555555b120 in inline::main () at /home/m4b/tmp/bad_debug/inline.rs:20
```
Prevent unwinding past FFI boundaries
Second attempt to write a patch to solve this.
r? @nikomatsakis
~~So, my biggest issue with this patch is the way the patch determines *what* functions should have an abort landing pad (in `construct_fn`). I would ideally have this code match [src/librustc_trans/callee.rs::get_fn](https://github.com/rust-lang/rust/blob/master/src/librustc_trans/callee.rs#L107-L115) but couldn't find an id that returns true for `is_foreign_item`. Also tried `tcx.has_attr("unwind")` with no luck.~~ FIXED
Other issues:
* llvm.trap is an SIGILL on amd64. Ideally we could use panic-abort's version of aborting which is nicer but we don't want to depend on that library...
* ~~Mir inlining is a stub currently.~~ FIXED (no-op)
Also, when reviewing please take into account that I'm new to the code and only partially know what I'm doing... and that I've mostly made made matches on `TerminatorKind::Abort` match either `TerminatorKind::Resume` or `TerminatorKind::Unreachable` based on what looked best.
This commit is the next attempt to enable multiple codegen units by default in
release mode, getting some of those sweet, sweet parallelism wins by running
codegen in parallel. Performance should not be lost due to ThinLTO being on by
default as well.
Closes#45320
incr.comp.: Use an array instead of a hashmap for storing result hashes.
Doing so should result in some of the core tracking components being faster.
r? @nikomatsakis
Followup for #46112.
Sorting by crate-num should ensure that we favor `std::foo::bar` over
`any_other_crate::foo::bar`.
Interestingly, *this* change had a much larger impact on our internal
test suite than PR #46708 (which was my original fix to #46112).
Issue #46589 - Kill borrows on a local variable whenever we assign ov…
…er this variable
This is a first patch for the issue, handling the simple case while I figure out the data structures involved in the more complex cases.
Do not emit type errors on recovered blocks
When a parse error occurs on a block, the parser will recover and create
a block with the statements collected until that point. Now a flag
stating that a recovery has been performed in this block is propagated
so that the type checker knows that the type of the block (which will be
identified as `()`) shouldn't be checked against the expectation to
reduce the amount of irrelevant diagnostic errors shown to the user.
Fix#44579.
When a parse error occurs on a block, the parser will recover and create
a block with the statements collected until that point. Now a flag
stating that a recovery has been performed in this block is propagated
so that the type checker knows that the type of the block (which will be
identified as `()`) shouldn't be checked against the expectation to
reduce the amount of irrelevant diagnostic errors shown to the user.
rustc: Sort CGUs before merging
This commit fixes some nondeterminism in compilation when using multiple codegen
units. The algorithm for splitting codegen units currently takes the
otherwise-would-be-for-incremental partitioning and then continuously merges the
two smallest codegen units until the desired number of codegen units are
reached.
We want to be sure to merge the same codegen units each time a compilation is
run but there's some subtle reorderings amongst all the items which was causing
this step to be slightly buggy. Notably this step involves sorting codegen units
by size, but if two codegen units had the same size they would appear in
different locations in the list each time.
This commit fixes this issue by sorting codegen units by name before doing the
loop to merge the two smallest. This means that we've got a deterministic
order going in and since we're using a stable sort this should mean that we're
always now getting a deterministic merging of codegen units.
Closes#46846
Generics refactoring (groundwork for const generics)
These changes were suggested by @eddyb.
After this change, the `Generics` contain one `Vec` of an enum for the generic parameters, rather than two separate `Vec`s for lifetime and type parameters. Type params and const params will need to be in a shared `Vec` to preserve their ordering, and moving lifetimes into the same `Vec` should simplify the code that processes `Generics`.
docs: do not call integer overflows as underflows
In the API docs, integer overflow is sometimes called underflow. Underflow is really when the magnitude of a floating-point number is too small so the number underflows to subnormal or zero. With integers it is always overflow, even if the expected result is less than the minimum number that can be represented.
tweaks and fixes for doc(include)
This PR makes a handful of changes around `#[doc(include="file.md")]` (https://github.com/rust-lang/rust/issues/44732):
* Turns errors when loading files into full errors. This matches the original RFC text.
* Makes the `missing_docs` lint check for `#[doc(include="file.md")]` as well as regular `#[doc="text"]` attributes.
* Loads files included by `#[doc(include="file.md")]` into dep-info, mirroring the behavior of `include_str!()` and friends.
* Adds or modifies tests to check for all of these.
incr.comp.: Precompute small hash for filenames to save some work.
For each span we hash the filename of the file it points to. Since filenames can be quite long, especially with absolute paths, this PR pre-computes a hash of the filename and we then only hash the hash.
r? @nikomatsakis
Prevent rustc overwriting input files
If rustc is invoked on a file that would be overwritten by the
compilation, the compilation now fails, to avoid accidental loss. This
resolves#13019. Kudos to @estebank, whose patch I finished off.
rustc: do not raise the alignment of optimized enums to the niche's alignment.
This is the improved fix for #46769 that does not increase the size of any types (see also #46808).
Fix ICE when calling non-functions within closures
The visitor for walking function bodies did not previously properly
handle error-cases for function calls. These are now ignored,
preventing the panic. This fixes#46771.
