Fix regression in promotion of rvalues referencing a static
This commit makes librustc_passes::consts::CheckCrateVisitor properly
mark expressions as promotable if they reference a static, as it's
perfectly fine for one static to reference another. It fixes a
regression that prevented a temporary rvalue from referencing a static
if it was itself declared within a static.
Prior to commit b8c05fe90b,
`region::ScopeTree` would only register a 'terminating scope' for function
bodies. Thus, while rvalues in a static that referenced a static would be marked
unpromotable, the lack of enclosing scope would cause
mem_categorization::MemCategorizationContext::cat_rvalue_node
to compute a 'temporary scope' of `ReStatic`. Since this had the same
effect as explicitly selecting a scope of `ReStatic`
due to the rvalue being marked by CheckCrateVisitor as promotable,
no issue occurred.
However, commit b8c05fe90b
made ScopeTree unconditionally register a 'terminating scope'
Since mem_categorization would now compute a non-static 'temporary scope', the
aforementioned rvalues would be erroneously marked as living for too
short a time.
By fixing the behavior of CheckCrateVisitor, this commit avoids changing
mem_categorization's behavior, while ensuring that temporary values in
statics are still allowed to reference other statics.
Fixes issue #44373
Add `TargetOptions::min_global_align`, with s390x at 16-bit
The SystemZ `LALR` instruction provides PC-relative addressing for globals,
but only to *even* addresses, so other compilers make sure that such
globals are always 2-byte aligned. In Clang, this is modeled with
`TargetInfo::MinGlobalAlign`, and `TargetOptions::min_global_align` now
serves the same purpose for rustc.
In Clang, the only targets that set this are SystemZ, Lanai, and NVPTX, and
the latter two don't have targets in rust master.
Fixes#44411.
r? @eddyb
Fix sanitizer tests on buggy kernels
Travis recently pushed an update to the Linux environments, namely the kernels
that we're running on. This in turn caused some of the sanitizer tests we run to
fail. We also apparently weren't the first to hit these failures! Detailed in
google/sanitizers#837 these tests were failing due to a specific commit in the
kernel which has since been backed out, but for now work around the buggy kernel
that's deployed on Travis and eventually we should be able to remove these
flags.
Properly detect overflow in Instance ± Duration.
Fix#44216.
Fix#42622
The computation `Instant::now() + Duration::from_secs(u64::max_value())` now panics. The call `receiver.recv_timeout(Duration::from_secs(u64::max_value()))`, which involves such time addition, will also panic.
The reason #44216 arises is because of an unchecked cast from `u64` to `i64`, making the duration equivalent to -1 second.
Note that the current implementation is over-conservative, since e.g. (-2⁶²) + (2⁶³) is perfectly fine for an `i64`, yet this is rejected because (2⁶³) overflows the `i64`.
Extend E0623 for LateBound and EarlyBound Regions
This is a fix for #43882
```
fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
x.push(y);
}
```
now gives
```
error[E0623]: lifetime mismatch
--> $DIR/ex3-both-anon-regions-latebound-regions.rs:12:12
|
11 | fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
| ------ ------ these two types are declared with different lifetimes...
12 | x.push(y);
| ^ ...but data from `y` flows into `x` here
```
cc @nikomatsakis @arielb1
Please ignore the second commit. It will be merged in a separate PR.
Expect pipe symbol after closure parameter list
Fixes#44021.
---
Originally, the parser just called `bump` to discard following token after parsing closure parameter list, because it assumes `|` is following. However, the following code breaks the assumption:
```rust
struct MyStruct;
impl MyStruct {
fn f() {|x, y}
}
```
Here, the parameter list is `x, y` and the following token is `}`. The parser discards `}`, and then we have a curly bracket mismatch.
Indeed, this code has a syntax error. On current nightly, the compiler emits an syntax error, but with incorrect message and span, followed by an ICE.
```
error: expected expression, found `}`
--> 44021.rs:4:1
|
4 | }
| ^
error: internal compiler error: unexpected panic
```
Even worse, on current stable(1.20.0), the compiler falls into an infinite loop.
This pull request fixes this problem. Now the compiler emits correct error message and span, and does not ICE.
```
error: expected one of `:`, `@`, or `|`, found `}`
--> 44021.rs:3:20
|
3 | fn foo() {|x, y}
| ^ expected one of `:`, `@`, or `|` here
```
rustc: Separately feature gate repr(i128)
Brought up during the discussion of #35118, the support for this is still
somewhat buggy and so stabilization likely wants to be considered independently
of the type itself.
Use rvalue promotion to 'static instead of static items.
Fixes#44240. Among other things, in crates that do a lot of formatting, this could reduce the number of items, although I haven't measured the performance benefits. If there's a codegen slowdown, that should IMO be solved by caching the output of miri, *not* by using `static`.
r? @alexcrichton
rustc: Remove `DepGraph` handling from rustc_metadata
This should now be entirely tracked through queries, so no need to have a
`DepGraph` in the `CStore` object any more!
cc #44390
Add libbacktrace support for Apple platforms (resubmitted)
Resubmitting #43422 rebased on the current master (cc @JohnColanduoni).
I have added an additional commit to fallback to `dladdr`-based `resolve_symbol` if `libbacktrace` returns `None`, otherwise the stack trace will be full of `<unknown>` when you forget to pass the `-g` flag (actually it seems — at least on macOS — the `dladdr` symbol is more accurate than the `libbacktrace` one).
Allow Drop types in const's too, with #![feature(drop_types_in_const)].
Implements the remaining amendment, see #33156. cc @SergioBenitez
r? @nikomatsakis
This commit makes librustc_passes::consts::CheckCrateVisitor properly
mark expressions as promotable if they reference a static, as it's
perfectly fine for one static to reference another. It fixes a
regression that prevented a temporary rvalue from referencing a static
if it was itself declared within a static.
Prior to commit b8c05fe90b,
`region::ScopeTree` would only register a 'terminating scope' for function
bodies. Thus, while rvalues in a static that referenced a static would be marked
unpromotable, the lack of enclosing scope would cause
mem_categorization::MemCategorizationContext::cat_rvalue_node
to compute a 'temporary scope' of `ReStatic`. Since this had the same
effect as explicitly selecting a scope of `ReStatic`
due to the rvalue being marked by CheckCrateVisitor as promotable,
no issue occurred.
However, commit b8c05fe90b
made ScopeTree unconditionally register a 'terminating scope'
Since mem_categorization would now compute a non-static 'temporary scope', the
aforementioned rvalues would be erroneously marked as living for too
short a time.
By fixing the behavior of CheckCrateVisitor, this commit avoids changing
mem_categorization's behavior, while ensuring that temporary values in
statics are still allowed to reference other statics.
Fixes issue #44373
Migrate a slew of metadata methods to queries
This PR intends to make more progress on #41417, knocking off some low-hanging fruit.
Closes#44190
cc #44137
pprust: fix parenthesization of exprs
The pretty printer in `syntax::print::pprust` currently relies on the presence of `ExprKind::Paren` hints in order to correctly parenthesize expressions in its output. If `Paren` nodes are missing, it sometimes produces wrong output, such as printing `1 - (2 - 3)` as `1 - 2 - 3`. This PR fixes `pprust` to correctly print expressions regardless of the presence or absence of `Paren` nodes. This should make `pprust` easier to use with programmatically constructed ASTs.
A few notes:
* I added a function for assigning precedence values to exprs in `syntax::util::parser`, since there is already code there for assigning precedence values to binops. Let me know if I should move this somewhere more `pprust`-specific.
* I also moved the `contains_exterior_struct_lit` function from `rustc_lint::unused::UnusedParens` into `syntax::util::parser`, since it's needed for determining the correct parenthesization of `if`/`while` conditional expressions.
* I couldn't find a good way to compare two exprs for equivalence while ignoring semantically-irrelevant details like spans. So the test for the new behavior relies on a slight hack: it adds `Paren` nodes everywhere, so that the pretty-printed version exactly reflects the structure of the AST, and then compares the printed strings. This works, but let me know if there's a better way.
Travis recently pushed an update to the Linux environments, namely the kernels
that we're running on. This in turn caused some of the sanitizer tests we run to
fail. We also apparently weren't the first to hit these failures! Detailed in
google/sanitizers#837 these tests were failing due to a specific commit in the
kernel which has since been backed out, but for now work around the buggy kernel
that's deployed on Travis and eventually we should be able to remove these
flags.
Debugflag: -Z emit-end-regions
Skip EndRegion emission by default. Use `-Z emit-end-regions` to reenable it.
The main intent is to fix cases where `EndRegion` emission is believed to be causing excess peak memory pressure.
It may also be a welcome change to people inspecting the MIR output who find the EndRegions to be a distraction.
(In later follow-up PR's I will put in safe-guards against using the current mir-borrowck without enabling `EndRegion` emission. But I wanted this PR to be minimal, in part because we may wish to backport it to the beta channel if we find that it reduces peak memory usage significantly.)
Make the LocalKey facade of thread_local! inlineable cross-crate.
Fixes (almost*) #25088 by changing the `LocalKey` `static` `thread_local!` generates to a `const`.
This can be done because a `LocalKey` value holds no actual TLS data, only function pointers to get at said data, and it could even be made `Copy` without any negative consequences.
The recent stabilization of rvalue promotion to `'static` allows doing this without changing the API.
r? @alexcrichton
*almost because we can't yet inline `__getit` because it breaks on MSVC, see https://github.com/rust-lang/rust/pull/43931#issuecomment-323534214
rustc: Attempt to handle super long linker invocations
This commit adds logic to the compiler to attempt to handle super long linker
invocations by falling back to the `@`-file syntax if the invoked command is too
large. Each OS has a limit on how many arguments and how large the arguments can
be when spawning a new process, and linkers tend to be one of those programs
that can hit the limit!
The logic implemented here is to unconditionally attempt to spawn a linker and
then if it fails to spawn with an error from the OS that indicates the command
line is too big we attempt a fallback. The fallback is roughly the same for all
linkers where an argument pointing to a file, prepended with `@`, is passed.
This file then contains all the various arguments that we want to pass to the
linker.
Closes#41190
This commit adds logic to the compiler to attempt to handle super long linker
invocations by falling back to the `@`-file syntax if the invoked command is too
large. Each OS has a limit on how many arguments and how large the arguments can
be when spawning a new process, and linkers tend to be one of those programs
that can hit the limit!
The logic implemented here is to unconditionally attempt to spawn a linker and
then if it fails to spawn with an error from the OS that indicates the command
line is too big we attempt a fallback. The fallback is roughly the same for all
linkers where an argument pointing to a file, prepended with `@`, is passed.
This file then contains all the various arguments that we want to pass to the
linker.
Closes#41190
