Historically this was done to accommodate bugs in lints, but there hasn't been a
bug in a lint since this feature was added which the warnings affected. Let's
completely purge warnings from all our stages by denying warnings in all stages.
This will also assist in tracking down `stage0` code to be removed whenever
we're updating the bootstrap compiler.
Adds `-Z mir-stats`, which is similar to `-Z hir-stats`.
Adds `-Z mir-stats`, which is similar to `-Z hir-stats`.
Some notes:
* This code attempts to present the breakdown of each variant for
every enum in the MIR. This is meant to guide decisions about how to
revise representations e.g. when to box payloads for rare variants
to shrink the size of the enum overall.
* I left out the "Total:" line that hir-stats presents, because this
implementation uses the MIR Visitor infrastructure, and the memory
usage of structures directly embedded in other structures (e.g. the
`func: Operand` in a `TerminatorKind:Call`) is not distinguished
from similar structures allocated in a `Vec` (e.g. the `args:
Vec<Operand>` in a `TerminatorKind::Call`). This means that a naive
summation of all the accumulated sizes is misleading, because it
will double-count the contribution of the `Operand` of the `func` as
well as the size of the whole `TerminatorKind`.
* I did consider abandoning the MIR Visitor and instead hand-coding
a traversal that distinguished embedded storage from indirect
storage. But such code would be fragile; better to just require
people to take care when interpreting the presented results.
* This traverses the `mir.promoted` rvalues to capture stats for MIR
stored there, even though the MIR visitor super_mir method does not
do so. (I did not observe any promoted mir being newly traversed when
compiling the rustc crate, however.)
* It might be nice to try to unify this code with hir-stats. Then
again, the reporting portion is the only common code (I think), and
it is small compared to the visitors in hir-stats and mir-stats.
Some notes:
* This code attempts to present the breakdown of each variant for
every enum in the MIR. This is meant to guide decisions about how to
revise representations e.g. when to box payloads for rare variants
to shrink the size of the enum overall.
* I left out the "Total:" line that hir-stats presents, because this
implementation uses the MIR Visitor infrastructure, and the memory
usage of structures directly embedded in other structures (e.g. the
`func: Operand` in a `TerminatorKind:Call`) is not distinguished
from similar structures allocated in a `Vec` (e.g. the `args:
Vec<Operand>` in a `TerminatorKind::Call`). This means that a naive
summation of all the accumulated sizes is misleading, because it
will double-count the contribution of the `Operand` of the `func` as
well as the size of the whole `TerminatorKind`.
* I did consider abandoning the MIR Visitor and instead hand-coding
a traversal that distinguished embedded storage from indirect
storage. But such code would be fragile; better to just require
people to take care when interpreting the presented results.
* This traverses the `mir.promoted` rvalues to capture stats for MIR
stored there, even though the MIR visitor super_mir method does not
do so. (I did not observe any new mir being traversed when compiling
the rustc crate, however.)
* It might be nice to try to unify this code with hir-stats. Then
again, the reporting portion is the only common code (I think), and
it is small compared to the visitors in hir-stats and mir-stats.
Stabilize `..` in tuple (struct) patterns
I'd like to nominate `..` in tuple and tuple struct patterns for stabilization.
This feature is a relatively small extension to existing stable functionality and doesn't have known blockers.
The feature first appeared in Rust 1.10 6 months ago.
An example of use: https://github.com/rust-lang/rust/pull/36203
Closes https://github.com/rust-lang/rust/issues/33627
r? @nikomatsakis
This commit removes the `-D warnings` flag being passed through the makefiles to
all crates to instead be a crate attribute. We want these attributes always
applied for all our standard builds, and this is more amenable to Cargo-based
builds as well.
Note that all `deny(warnings)` attributes are gated with a `cfg(stage0)`
attribute currently to match the same semantics we have today
this makes sure the checks run before typeck (which might use the constant or const
function to calculate an array length) and gives prettier error messages in case of for
loops and such (since they aren't expanded yet).
