[experimental]: Build LLVM with ThinLTO enabled (2nd attempt)
This is https://github.com/rust-lang/rust/pull/51207 revived. This time, I'd like to run actual performance tests to see if it improves compile times.
Add some more wording to module documentation regarding how
`Arc::clone()` works, as some users have assumed cloning Arc's
to work via dereferencing to inner value as follows:
use std::sync::Arc;
let myarc = Arc::new(1);
let myarcref = myarc.clone();
assert!(1 == myarcref);
Instead of the actual mechanic of referencing the existing
Arc value:
use std::sync::Arg;
let myarc = Arc::new(1);
let myarcref = myarc.clone();
assert!(myarcref == &myarc); // not sure if assert could assert this
in the real world
create a valid DefIdTable for proc macro crates
At least the incremental compilation code, and a few other places in the
compiler, require the CrateMetadata for a loaded target crate to contain a
valid DefIdTable for the DefIds in the target.
Previously, the CrateMetadata for a proc macro contained the crate's
"host" DefIdTable, which is of course incompatible with the "target"
DefIdTable, causing ICEs. This creates a DefIdTable that properly refers
to the "proc macro" DefIds.
Fixes#49482.
r? @michaelwoerister
Should we beta-nominate this?
This splits "valid" into "valid for reads" and "valid for writes", and
also adds the concept of operation size to validity. Now functions which
operate on sequences state that e.g. pointer args must be "valid for reads of
size x".
The enumerated list of conditions is replaced by an explanation that
rust doesn't have a formal memory model. It does say that pointers
created directly from references are guaranteed to be valid, and links
to both the "Unsafe Code" section of the book and the "Undefined
Behavior" section of the reference.
- Add links to the GNU libc docs for `memmove`, `memcpy`, and
`memset`, as well as internally linking to other functions in `std::ptr`
- List invariants which, when violated, cause UB for all functions
- Add example to `ptr::drop_in_place` and compares it to `ptr::read`.
- Add examples which more closely mirror real world uses for the
functions in `std::ptr`. Also, move the reimplementation of `mem::swap`
to the examples of `ptr::read` and use a more interesting example for
`copy_nonoverlapping`.
- Change module level description
- Define what constitutes a "valid" pointer.
- Centralize discussion of ownership of bitwise copies in `ptr::read` and
provide an example.
rustc: Suggest removing `extern crate` in 2018
This commit updates the `unused_extern_crates` lint to make automatic
suggestions about removing `extern crate` annotations in the 2018 edition. This
ended up being a little easier than originally though due to what's likely been
fixed issues in the resolver!
Closes#52829
Remove `AccumulateVec` and its uses.
It's basically just a less capable version of `SmallVec`.
FWIW, the only use of `ArrayVec` is now within `HybridIdxSet`.
r? @Mark-Simulacrum
Fix warnings about the `native` target-cpu
This fixes a regression from #53031 where specifying `-C target-cpu=native` is
printing a lot of warnings from LLVM about `native` being an unknown CPU. It
turns out that `native` is indeed an unknown CPU and we have to perform a
mapping to an actual CPU name, but this mapping is only performed in one
location rather than all locations we inform LLVM about the target CPU.
This commit centralizes the mapping of `native` to LLVM's value of the native
CPU, ensuring that all locations we inform LLVM about the `target-cpu` it's
never `native`.
Closes#53322
Miri engine cleanup
* Unify the two maps in memory to store the allocation and its kind together.
* Share the handling of statics between CTFE and miri: The miri engine always
uses "lazy" `AllocType::Static` when encountering a static. Acessing that
static invokes CTFE (no matter the machine). The machine only has any
influence when writing to a static, which CTFE outright rejects (but miri
makes a copy-on-write).
* Add an `AllocId` to by-ref consts so miri can use them as operands without
making copies.
* Move responsibilities around for the `eval_fn_call` machine hook: The hook
just has to find the MIR (or entirely take care of everything); pushing the
new stack frame is taken care of by the miri engine.
* Expose the intrinsics and lang items implemented by CTFE so miri does not
have to reimplement them.
* Allow Machine to hook into foreign statics (used by miri to get rid of some other hacks).
* Clean up function calling.
* Switch const sanity check to work on operands, not mplaces.
* Move const_eval out of rustc_mir::interpret, to make sure that it does not access private implementation details.
In particular, we can finally make `eval_operand` take `&self`. :-)
Should be merged after https://github.com/rust-lang/rust/pull/53609, across which I will rebase.
This script invokes the gdbgui graphical GDB front-end
with the Rust pretty printers loaded. The script does not install
gdbgui, that must be done manually.
This fixes a regression from #53031 where specifying `-C target-cpu=native` is
printing a lot of warnings from LLVM about `native` being an unknown CPU. It
turns out that `native` is indeed an unknown CPU and we have to perform a
mapping to an actual CPU name, but this mapping is only performed in one
location rather than all locations we inform LLVM about the target CPU.
This commit centralizes the mapping of `native` to LLVM's value of the native
CPU, ensuring that all locations we inform LLVM about the `target-cpu` it's
never `native`.
Closes#53322
add more Cortex-R targets
This expands on PR #53663 to complete the set of Cortex-R targets and builds
rust-std components for them.
r? @alexcrichton
each extra rust-std component (there's 4 of them) takes about 3 minutes to build
on my local machine. In terms of stability (LLVM codegen bugs) these new targets
should be as stable as the Cortex-M ones (e.g. `thumbv7m-none-eabi`).
If the extra build time is too much we can leave the rust-std components out for
now
closes#53663
cc @paoloteti
