Check for overflow in DroplessArena and align returned memory
* Check for overflow when calculating the slice start & end position.
* Align the pointer obtained from the allocator, ensuring that it
satisfies user requested alignment (the allocator is only asked for
layout compatible with u8 slice).
* Remove an incorrect assertion from DroplessArena::align.
* Avoid forming references to an uninitialized memory in DroplessArena.
Helps with #73007, #72624.
Avoid prematurely recording toolstates
When we're running with dry_run enabled (i.e. all builds do this initially), we're
guaranteed to save of a toolstate of TestFail for tools that aren't tested. In practice,
we do test tools as well, so for those tools we would initially record them as being
TestPass, and then later on re-record the correct state after actually testing them.
However, this would not work well if the build failed for whatever reason (e.g. panicking
in bootstrap, or as was the case in #73097, clippy failing to test successfully), we would
just go on believing that things passed when they in practice did not.
This commit also adjusts saving toolstate to never record clippy explicitly (otherwise, it
would be recorded when building it); eventually that'll likely move to other tools as well
but not yet. This is deemed simpler than checking everywhere we generically save
toolstate.
We also move clippy out of the "toolstate" no-fail-fast build into a separate x.py
invocation; this should no longer be technically required but provides the nice state of
letting us check toolstate for all tools and only then check clippy (giving full results
on every build).
r? @oli-obk
Supercedes #73275, also fixes#73274
This commit modifies bootstrap so that `config.toml` is read first from
`RUST_BOOTSTRAP_CONFIG`, then `--config` and finally `config.toml` in the
current directory.
This is a subjective change, intended to improve the ergnomics when
using "development shells" for rustc development (for example, using tools
such as Nix) which set environment variables to ensure a reproducible
environment (these development shells can then be version controlled). By
optionally reading `config.toml` from an environment variable, a `config.toml`
can be defined in the development shell and a path to it exposed in the
`RUST_BOOTSTRAP_CONFIG` environment variable - avoiding the need to manually
symlink the contents of this file to `config.toml` in the working
directory.
Signed-off-by: David Wood <david@davidtw.co>
store `ObligationCause` on the heap
Stores `ObligationCause` on the heap using an `Rc`.
This PR trades off some transient memory allocations to reduce the size of–and thus the number of instructions required to memcpy–a few widely used data structures in trait solving.
This initial version only injects counters at the top of each function.
Rust Coverage will require injecting additional counters at each
conditional code branch.
When we're running with dry_run enabled (i.e. all builds do this initially), we're
guaranteed to save of a toolstate of TestFail for tools that aren't tested. In practice,
we do test tools as well, so for those tools we would initially record them as being
TestPass, and then later on re-record the correct state after actually testing them.
However, this would not work well if the build failed for whatever reason (e.g. panicking
in bootstrap, or as was the case in 73097, clippy failing to test successfully), we would
just go on believing that things passed when they in practice did not.
This commit also adjusts saving toolstate to never record clippy explicitly (otherwise, it
would be recorded when building it); eventually that'll likely move to other tools as well
but not yet. This is deemed simpler than checking everywhere we generically save
toolstate.
We also move clippy out of the "toolstate" no-fail-fast build into a separate x.py
invocation; this should no longer be technically required but provides the nice state of
letting us check toolstate for all tools and only then check clippy (giving full results
on every build).
PR #49778 introduced fs::canonicalize() which fails for a nonexistent path.
This is a surprise for someone used to GNU Autotools' configure which can create any necessary intermediate directories in prefix.
This change makes it run fs::create_dir_all() before canonicalize().
