This PR is a rebase of the original PR by @eddyb https://github.com/rust-lang/rust/pull/21836 with some unrebasable parts manually reapplied, feature gate added + type equality restriction added as described below.
This implementation is partial because the type equality restriction is applied to all type ascription expressions and not only those in lvalue contexts. Thus, all difficulties with detection of these contexts and translation of coercions having effect in runtime are avoided.
So, you can't write things with coercions like `let slice = &[1, 2, 3]: &[u8];`. It obviously makes type ascription less useful than it should be, but it's still much more useful than not having type ascription at all.
In particular, things like `let v = something.iter().collect(): Vec<_>;` and `let u = t.into(): U;` work as expected and I'm pretty happy with these improvements alone.
Part of https://github.com/rust-lang/rust/issues/23416
LLVM doesn't really support reusing the same module to emit more than
one file. One bug this causes is that the IR is invalidated by the stack
coloring pass when emitting the first file, and then the IR verifier
complains by the time we try to emit the second file. Also, we get
different binaries with --emit=asm,link than with just --emit=link. In
some cases leading to segfaults.
Unfortunately, it seems that at this point in time, the most sensible
option to circumvent this problem is to just clone the whole llvm module
for the asm output if we need both, asm and obj file output.
Fixes#24876Fixes#26235
LLVM doesn't really support reusing the same module to emit more than
one file. One bug this causes is that the IR is invalidated by the stack
coloring pass when emitting the first file, and then the IR verifier
complains by the time we try to emit the second file. Also, we get
different binaries with --emit=asm,link than with just --emit=link. In
some cases leading to segfaults.
Unfortunately, it seems that at this point in time, the most sensible
option to circumvent this problem is to just clone the whole llvm module
for the asm output if we need both, asm and obj file output.
Fixes#24876Fixes#26235
Still will not translate references to items like `X` or `Y::V` where
```
struct X;
enum Y { V }
```
but I must go work on university things so I’m PRing what I have.
r? @nikomatsakis
This fixes a bug in which unused imports can get wrongly marked as used when checking for unused qualifications in `resolve_path` (issue #30078), and it removes unused imports that were previously undetected because of the bug.
We can now handle name resolution errors and get past type checking (if we're a bit lucky). This is the first step towards doing code completion for partial programs (we need error recovery in the parser and early access to save-analysis).
What I've done here is try to make the code match what vcvars does much more closely. It now chooses which SDK to find based on the version of MSVC that it found. It also bases the decision of whether to find all the things on whether `VCINSTALLDIR` has been set, which is more likely to have only been set by an invocation of vcvars, unlike previously where it would do some things only if `LIB` wasn't set even though there was a valid use case for libraries to add themselves to `LIB` without having invoked vcvars.
There are still some debug `println!`s so people can test the PR and make sure it works correctly on various setups.
It supports VS 2015, 2013, and 2012. People who want to use versions of VS older (or newer) than that will have to manually invoke the appropriate vcvars bat file to set the proper environment variables themselves.
Do not merge yet.
Fixes https://github.com/rust-lang/rust/issues/30229
This handles cases when the LLVM used isn't configured will the 'usual' targets. Also, cases where LLVM is shared are also handled (ie with `LD_LIBRARY_PATH` etc).
This PR reverts #29543 and instead implements proper support for "=*m" and "+*m" indirect output operands. This provides a framework on top of which support for plain memory operands ("m", "=m" and "+m") can be implemented.
This also fixes the liveness analysis pass not handling read/write operands correctly.
This handles cases when the LLVM used isn't configured will the 'usual'
targets. Also, cases where LLVM is shared are also handled (ie with
`LD_LIBRARY_PATH` etc).
r? @nagisa
I'm going to need the `ConstVal` -> `ValueRef` translation to start removing trans/consts piece by piece. If you need anything implemented in the translation, feel free to assign an issue to me.
Fixes#26403
This adjusts the pointer, if needed, to the correct alignment by using the alignment information in the vtable.
Handling zero might not be necessary, as it shouldn't actually occur. I've left it as it's own commit so it can be removed fairly easily if people don't think it's worth doing. The way it's handled though means that there shouldn't be much impact on performance.
Instead of `ast::Ident`, bindings, paths and labels in HIR now keep a new structure called `hir::Ident` containing mtwt-renamed `name` and the original not-renamed `unhygienic_name`. `name` is supposed to be used by default, `unhygienic_name` is rarely used.
This is not ideal, but better than the status quo for two reasons:
- MTWT tables can be cleared immediately after lowering to HIR
- This is less bug-prone, because it is impossible now to forget applying `mtwt::resolve` to a name. It is still possible to use `name` instead of `unhygienic_name` by mistake, but `unhygienic_name`s are used only in few very special circumstances, so it shouldn't be a problem.
Besides name resolution `unhygienic_name` is used in some lints and debuginfo. `unhygienic_name` can be very well approximated by "reverse renaming" `token::intern(name.as_str())` or even plain string `name.as_str()`, except that it would break gensyms like `iter` in desugared `for` loops. This approximation is likely good enough for lints and debuginfo, but not for name resolution, unfortunately (see https://github.com/rust-lang/rust/issues/27639), so `unhygienic_name` has to be kept.
cc https://github.com/rust-lang/rust/issues/29782
r? @nrc
The presence of the drop flag caused the offset calculation to be
incorrect, leading to the pointer being incorrect. This has been fixed
by calculating the offset based on the field index (and not assuming
that the field is always the last one).
However, I've also stopped the drop flag from being added to the end of
unsized structs to begin with. Since it's not actually accessed for
unsized structs, and isn't actually where we would say it is, this made
more sense.
