Rationale: some ISAs, e.g. OR1K, do not have atomic instructions
for byte and halfword access, and at the same time do not have
a fixed endianness, which makes it unreasonable to implement these
through word-sized atomic accesses.
Redox Cross Compilation
I will admit - there are things here that I wish I did not have to do. This completes the ability to create a cross compiler from the rust repository for `x86_64-unknown-redox`. I will document this PR with inline comments explaining some things.
[View this gist to see how a cross compiler is built](https://gist.github.com/jackpot51/6680ad973986e84d69c79854249f2b7e)
Prior discussion of a smaller change is here: https://github.com/rust-lang/rust/pull/38366
Cleanup refactoring around DefPath handling
This PR makes two big changes:
* All DefPaths of a crate are now stored in metadata in their own table (as opposed to `DefKey`s as part of metadata `Entry`s.
* The compiler will no longer allocate a pseudo-local DefId for inlined HIR nodes (because those are gross). Inlined HIR nodes will have a NodeId but they don't have there own DefId anymore. Turns out they were not needed anymore either. Hopefully HIR inlining will be gone completely one day but if until then we start needing to be able to map inlined NodeIds to original DefIds, we can add an additional table to metadata that allows for reconstructing this.
Overall this makes for some nice simplifications and removal of special cases.
r? @eddyb
cc @rust-lang/compiler
struct field reordering and optimization
This is work in progress. The goal is to divorce the order of fields in source code from the order of fields in the LLVM IR, then optimize structs (and tuples/enum variants)by always ordering fields from least to most aligned. It does not work yet. I intend to check compiler memory usage as a benchmark, and a crater run will probably be required.
I don't know enough of the compiler to complete this work unaided. If you see places that still need updating, please mention them. The only one I know of currently is debuginfo, which I'm putting off intentionally until a bit later.
r? @eddyb
Currently libraries installed by rustbuild on OSX have an incorrect
`LC_ID_DYLIB` directive located in the dynamic libraries that are
installed. The directive we expect looks like:
@rpath/libstd.dylib
Which means that if you want to find that dynamic library you should
look at the dylib's other `@rpath` directives. Typically our `@rpath`
directives look like `@loader_path/../lib` for the compiler as that's
where the installed libraries will be located. Currently, though,
rustbuild produces dylibs with the directive that looks like:
/Users/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-mac/build/build/x86_64-apple-darwin/stage1-std/x86_64-apple-darwin/release/deps/libstd-713ad88203512705.dylib
In other words, the build directory is encoded erroneously. The compiler
already [knows how] to change this directive, but it only passes that
argument when `-C rpath` is also passed. The rustbuild system, however,
explicitly [does not pass] this option explicitly and instead bakes its
own. This logic then also erroneously didn't pass `-Wl,-install_name`
like the compiler.
[knows how]: 4a008cccaa/src/librustc_trans/back/linker.rs (L210-L214)
[does not pass]: 4a008cccaa/src/bootstrap/bin/rustc.rs (L133-L158)
To fix this regression this patch introduces a new `-Z` flag, `-Z
osx-rpath-install-name` which basically just forces the compiler to take
the previous `-install_name` branch when creating a dynamic library.
Hopefully we can sort out a better rpath story in the future, but for
now this "hack" should suffice in getting our nightly builds back to the
same state as before.
Closes#38430
Remove the unused top level option by the same name, and retain the
debug option.
Use -Zmir-opt-level=1 as default.
One pass is enabled by default but wants to be optional:
- Instcombine requires mir_opt_level > 0
Copy propagation is not used by default, but used to be activated by
explicit -Zmir-opt-level=1. It must move one higher to be off by
default:
- CopyPropagation requires mir_opt_level > 1
Deaggregate is not used by default, and used to be on a different level
than CopyPropagation:
- Deaggreate requires mir_opt_level > 2
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.
add a `-Z incremental-dump-hash` flag
This causes us to dump a bunch of has information to stdout that can be
useful in tracking down incremental compilation invalidations,
particularly across crates.
print option to dump target spec as JSON
This lets the user dump out the target spec that the compiler is using. This is useful to people defining their own target.json to compare it against existing targets or understand how different targets change internal settings. It is also potentially useful for Cargo to determine if something has changed with a target and it needs to rebuild things.
This option provides the user the ability to dump the configuration that
is in use by rustc for the target they are building for.
Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
This causes us to dump a bunch of has information to stdout that can be
useful in tracking down incremental compilation invalidations,
particularly across crates.
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.
Biggest change: Revised print-type-sizes output to include breakdown
of layout.
Includes info about field sizes (and alignment + padding when padding
is injected; the injected padding is derived from the offsets computed
by layout module).
Output format is illustrated in commit that has the ui tests.
Note: there exists (at least) one case of variant w/o name: empty
enums. Namely, empty enums use anonymous univariant repr. So for such
cases, print the number of the variant instead of the name.
----
Also, eddyb suggested of reading from `layout_cache` post-trans.
(For casual readers: the compiler source often uses the word "cache"
for tables that are in fact not periodically purged, and thus are
useful as the basis for data like this.)
Some types that were previously not printed are now included in the
output. (See e.g. the tests `print_type_sizes/generics.rs` and
`print_type_sizes/variants.rs`)
----
Other review feedback:
switch to an exhaustive match when filtering in just structural types.
switch to hashset for layout info and move sort into print method.
----
Driveby change: Factored session::code_stats into its own module
----
incorporate njn feedback re output formatting.
Group unused import warnings per import list
Given a file
``` rust
use std::collections::{BinaryHeap, BTreeMap, BTreeSet};
fn main() {}
```
Show a single warning, instead of three for each unused import:
``` nocode
warning: unused imports, #[warn(unused_imports)] on by default
--> file2.rs:1:24
|
1 | use std::collections::{BinaryHeap, BTreeMap, BTreeSet};
| ^^^^^^^^^^ ^^^^^^^^ ^^^^^^^^
```
Include support for lints pointing at `MultilineSpan`s, instead of just
`Span`s.
Fixes#16132.
Marking the 'no-stack-check' codegen option as deprecated (Issue #34915)
Attempts to finish resolving issue #34915. Based on pull request #35156, which was closed due to inactivity.
Given a file
```rust
use std::collections::{BinaryHeap, BTreeMap, BTreeSet};
fn main() {}
```
Show a single warning, instead of three for each unused import:
```nocode
warning: unused imports, #[warn(unused_imports)] on by default
--> foo.rs:1:24
|
1 | use std::collections::{BinaryHeap, BTreeMap, BTreeSet};
| ^^^^^^^^^^ ^^^^^^^^ ^^^^^^^^
```
Include support for lints pointing at `MultilineSpan`s, instead of just
`Span`s.
Most of the Rust community agrees that the vec! macro is clearer when
called using square brackets [] instead of regular brackets (). Most of
these ocurrences are from before macros allowed using different types of
brackets.
There is one left unchanged in a pretty-print test, as the pretty
printer still wants it to have regular brackets.
introing one-time diagnostics: only emit "lint level defined here" once
This is a revised resubmission of PR #34084 (which was closed due to inactivity on account of time constraints on the author's part).
---
We introduce a new `one_time_diagnostics` field on
`rustc::session::Session` to hold a hashset of diagnostic messages we've
set once but don't want to see again (as uniquified by span and message
text), "lint level defined here" being the motivating example dealt with
here.
This is in the matter of #24690.
---
r? @nikomatsakis
Some lint-level attributes (like `bad-style`, or, more dramatically,
`warnings`) can affect more than one lint; it seems fairer to point out
the attribute once for each distinct lint affected. Also, a UI test is
added. This remains in the matter of #24690.
Jonathan D. Turner pointed out that we don't want to dedup in JSON
mode. Since the compile-test runner uses JSON output, we regrettably
need to revert the edits to existing tests; one imagines that testing
for one-time diagnosticity for humans will have to be added as a UI
test.
This remains in the matter of #24690.
We introduce a new `one_time_diagnostics` field on
`rustc::session::Session` to hold a hashset of diagnostic messages we've
set once but don't want to see again (as uniquified by span and message
text), "lint level defined here" being the motivating example dealt with
here.
This is in the matter of #24690.
