trans: Avoid weak linkage for closures when linking with MinGW.
This PR proposes one possible solution to #34793, the problem that prevents https://github.com/servo/servo/pull/12393 from landing. It applies the same strategy, that we already use for monomorphizations, to closures, that is, instead of emitting symbols with `weak_odr` linkage in order to avoid symbol conflicts, we emit them with `internal` linkage, with the side effect that we have to copy code instead of just linking to it, if more than one codegen unit is involved.
With this PR, the compiler will only apply this strategy for targets where we would actually run into a problem when using `weak_odr` linkage, in other words nothing will change for platforms except for MinGW.
The solution implemented here has one restriction that could be lifted with some more effort, but it does not seem to be worth the trouble since it will go away once we use only MIR-trans: If someone compiles code
1. on MinGW,
2. with more than one codegen unit,
3. *not* using MIR-trans,
4. and runs into a closure inlined from another crate
then the compiler will abort and suggest to compile either with just one codegen unit or `-Zorbit`.
What's nice about this is that I lays a foundation for also doing the same for generics: using weak linkage where possible and thus enabling some more space optimizations that the linker can do.
~~This PR also contains a test case for compiling a program that contains more than 2^15 closures. It's a huge, generated file with almost 100K LOCs. I did not commit the script for generating the file but could do so. Alternatively, maybe someone wants to come up with a way of doing this with macros.~~
The test file is implemented via macros now (thanks @alexcrichton!)
Opinions?
Fixes#34793.
cc @rust-lang/compiler
typeck: use a TypeVisitor in ctp
Use a TypeVisitor in ctp instead of `ty::walk`
This fixes a few cases where a region could be projected out of a trait while not being constrained by the type parameters, violating rust-lang/rfcs#447 and breaking soundness. As such, this is a [breaking-change].
Fixes#35139
r? @eddyb
Avoid writing a temporary closure kind
We used to write a temporary closure kind into the inference table, but
this could lead to obligations being incorrectled resolved before
inference had completed. This result could then be cached, leading to
further trouble. This patch avoids writing any closure kind until the
computation is complete.
Fixes#34349.
r? @arielb1 -- what do you think?
diagnostically note source of overruling outer forbid
When we emit E0453 (lint level attribute overruled by outer `forbid`
lint level), it could be helpful to note where the `forbid` level was
set, for the convenience of users who, e.g., believe that the correct
fix is to weaken the `forbid` to `deny`.
Suggest use of `--print target-list` when target is not found.
If given target could not be found suggest using `--print target-list`.
Previously, error has been reported as:
$ rustc --target 86-unknown-linux-gnu
error: Error loading target specification: Could not find specification for target "86-unknown-linux-gnu"
After changes it looks as follows:
$ rustc --target 86-unknown-linux-gnu
error: Error loading target specification: Could not find specification for target "x86-unknown-linux-gnu". Use `--print target-list` for a list of supported targets
If given target could not be found suggest using `--print target-list`.
Previously, error has been reported as:
$ rustc --target x86-unknown-linux-gnu
error: Error loading target specification: Could not find specification for target "x86-unknown-linux-gnu"
After changes it looks as follows:
rustc --target x86-unknown-linux-gnu
error: Error loading target specification: Could not find specification for target "x86-unknown-linux-gnu"
help: Use `--print target-list` for a list of built-in targets
Add ARM MUSL targets
Rebase of #33189.
I tested this by producing a std for `arm-unknown-linux-musleabi` then I cross compiled Hello world to said target. Checked that the produced binary was statically linked and verified that the binary worked under QEMU.
This depends on rust-lang/libc#341. I'll have to update this PR after that libc PR is merged.
I'm also working on generating ARM musl cross toolchain via crosstool-ng. Once I verified those work, I'll send a PR to rust-buildbot.
r? @alexcrichton
cc @timonvo
Fix build of compiler-rt on FreeBSD
Broken since ee6011fc71 removed cmake from the
process. There are likely other platforms still broken, but I didn't test on them.
Properly feature gate all unstable ABIs
Fixes https://github.com/rust-lang/rust/issues/34900
[breaking-change]
r? @pnkfelix
---
Function-visiting machinery for AST/HIR is surprisingly error-prone, it's *very* easy to miss some cases or visit something twice while writing a visitor. This is the true problem behind https://github.com/rust-lang/rust/issues/34900. I'll try to restructure these visitors a bit and send one more PR later.
When we emit E0453 (lint level attribute overruled by outer `forbid`
lint level), it could be helpful to note where the `forbid` level was
set, for the convenience of users who, e.g., believe that the correct
fix is to weaken the `forbid` to `deny`.
The targets are:
- `arm-unknown-linux-musleabi`
- `arm-unknown-linux-musleabihf`
- `armv7-unknown-linux-musleabihf`
These mirror the existing `gnueabi` targets.
All of these targets produce fully static binaries, similar to the
x86 MUSL targets.
For now these targets can only be used with `--rustbuild` builds, as
https://github.com/rust-lang/compiler-rt/pull/22 only made the
necessary compiler-rt changes in the CMake configs, not the plain
GNU Make configs.
I've tested these targets GCC 5.3.0 compiled again musl-1.1.12
(downloaded from http://musl.codu.org/). An example `./configure`
invocation is:
```
./configure \
--enable-rustbuild
--target=arm-unknown-linux-musleabi \
--musl-root="$MUSL_ROOT"
```
where `MUSL_ROOT` points to the `arm-linux-musleabi` prefix.
Usually that path will be of the form
`/foobar/arm-linux-musleabi/arm-linux-musleabi`.
Usually the cross-compile toolchain will live under
`/foobar/arm-linux-musleabi/bin`. That path should either by added
to your `PATH` variable, or you should add a section to your
`config.toml` as follows:
```
[target.arm-unknown-linux-musleabi]
cc = "/foobar/arm-linux-musleabi/bin/arm-linux-musleabi-gcc"
cxx = "/foobar/arm-linux-musleabi/bin/arm-linux-musleabi-g++"
```
As a prerequisite you'll also have to put a cross-compiled static
`libunwind.a` library in `$MUSL_ROOT/lib`. This is similar to [how
the x86_64 MUSL targets are built]
(https://doc.rust-lang.org/book/advanced-linking.html).
This is to pull in changes to support ARM MUSL targets.
This change also commits a couple of other cargo-generated changes
to other dependencies in the various Cargo.toml files.
syntax_ext: format: fix ICE with bad named arguments
Fixes#35082 by guarding against a new case of malformed invocation not previously covered.
r? @alexcrichton
Revert "Remove unused methods from MultiSpan"
This reverts commit f7019a4e2f.
That commit removed the only way to make a suggestion with more than one substitute. That feature is not used directly by rustc but exists and is used by Clippy. Bring it back until we come up with a better solution (suggestions don't use span labels, so it would make sense for them to use their own type).
Rational there: https://github.com/Manishearth/rust-clippy/pull/1119.
r? @jonathandturner
Cc @Manishearth
Rename _ to {integer} and {float} for unknown numeric types
This PR renames _ to {integer} or {float} for unknown numeric types, to help people parse error messages that have numeric types that haven't been nailed down.
Example:
```rust
fn main() {
let x: String = 4;
}
```
Before:
```
error[E0308]: mismatched types
--> quicktest.rs:2:21
|
2 | let x: String = 4;
| ^ expected struct `std::string::String`, found integral variable
|
= note: expected type `std::string::String`
= note: found type `_`
error: aborting due to previous error
```
after:
```
error[E0308]: mismatched types
--> quicktest.rs:2:21
|
2 | let x: String = 4;
| ^ expected struct `std::string::String`, found integral variable
|
= note: expected type `std::string::String`
= note: found type `{integer}`
error: aborting due to previous error
```
```
resolve: Exclude inaccessible names from single imports
If a single import resolves to an inaccessible name in some but not all namespaces, avoid importing the name in the inaccessible namespaces.
Currently, the inaccessible namespaces are imported but cause a privacy error when used.
r? @nrc
Add non-panicking abs() functions to all signed integer types.
Currently, calling abs() on one of the signed integer types might panic (in
debug mode at least) because the absolute value of the largest negative value
can not be represented in that signed type. Unlike all other integer
operations, there is currently not a non-panicking version on this function.
This seems to just be an oversight in the design, therefore just adding it now.
rustbuild: make backtraces (RUST_BACKTRACE) optional
but keep them enabled by default to maintain the status quo.
When disabled shaves ~56KB off every x86_64-unknown-linux-gnu
binary.
To disable backtraces you have to use a config.toml (see
src/bootstrap/config.toml.example for details) when building rustc/std:
$ python bootstrap.py --config=config.toml
---
r? @alexcrichton
cc rust-lang/rfcs#1417
Implement ARM personality routine in Rust.
Remove the `eh_personality_catch` lang item.
Use a simplified version of `cfg_if!` in libunwind.
Closes#34786
Better attribute and metaitem encapsulation throughout the compiler
This PR refactors most (hopefully all?) of the `MetaItem` interactions outside of `libsyntax` (and a few inside) to interact with MetaItems through the provided traits instead of directly creating / destruct / matching against them. This is a necessary first step to eventually converting `MetaItem`s to internally use `TokenStream` representations (which will make `MetaItem` interactions much nicer for macro writers once the new macro system is in place).
r? @nrc
