The arenas write the value to memory and then return a non-aliasing
reference to it. The returned reference can be mutable and can be
coerced to an immutable one.
[breaking-change]
Fixes `config.mk` so that it should not contain multiple inconsistent entries for the same option.
Used aforementioned variants to extract options that have explicit `putvar` calls associated with them in the subsequent code. When the explicit `putvar` call was conditional on some potentially complex condition, moved the `putvar` call out to the main control flow of the script so that it always runs if necessary.
----
As a driveby fix, captured the error exit when doing the test run of `rustc --version` from `CFG_LOCAL_RUST_ROOT`, and signal explicit configure failure when it did not run successfully. (If we cannot run `rustc`, we really shouldn't try to keep going.)
----
Fix#17887.
Used aforementioned variants to extract options that have explicit
`putvar` calls associated with them in the subsequent code. When the
explicit `putvar` call was conditional on some potentially complex
condition, moved the `putvar` call out to the main control flow of the
script so that it always runs if necessary.
----
As a driveby fix, captured the error exit when doing the test run of
`rustc --version` from `CFG_LOCAL_RUST_ROOT`, and signal explicit
configure failure when it did not run successfully. (If we cannot run
`rustc`, we really shouldn't try to keep going.)
----
Finally, in response to review feedback, went through and identified
cases where we had been calling `putvar` manually (and thus my naive
translation used `opt_nosave`/`valopt_nosave`), and then verified
whether a manual `putvar` was necessary (i.e., was each variable in
question manually computed somewhere in the `configure` script).
In cases that did not meet this criteria, I revised the code to use
the `opt`/`valopt` directly and removed the corresponding `putvar`,
cleaning things up a teeny bit.
----
Fix#17887.
Let's try if not running LLDB tests in parallel solves the sporadic deadlocks we've seen since enabling the LLDB test suite. Running the tests in parallel has lead to unstable behaviour in the past (with LLDB versions below 310.x.x). Maybe our new minimum LLDB version isn't quite up to it either.
cc @alexcrichton
Use the `is_shorthand` field introduced by #17813 (ead6c4b) to make the
prettyprinter output the shorthand form. Fixes a few places that set
`is_shorthand: true` when the pattern is not a PatIdent with the same
name as the field.
Explain that Rust has different pointer types because there is a
tradeoff between flexibility and efficiency. Motivate boxes as
fixed-size containers of variable-sized objects. Clarify that Box and Rc
are pointer types that you deref with * just like references. Stick to
explaining the semantics and avoid implementation details. Scope isn't
the most accurate framework to think about deallocation (since you
return boxes and otherwise move values out of scopes); it's more "when
the value is done being used," i.e., lifetime. Provide a connection
between Rust's pointer types by locating them on a flexibiltiy /
performance scale. Explain the compiler can't statically analyze
lifetimes with multiple owners; hence the need for (runtime) reference
counting.
