This commit tweaks the interface of the `std::env` module to make it more
ergonomic for common usage:
* `env::var` was renamed to `env::var_os`
* `env::var_string` was renamed to `env::var`
* `env::args` was renamed to `env::args_os`
* `env::args` was re-added as a panicking iterator over string values
* `env::vars` was renamed to `env::vars_os`
* `env::vars` was re-added as a panicking iterator over string values.
This should make common usage (e.g. unicode values everywhere) more ergonomic
as well as "the default". This is also a breaking change due to the differences
of what's yielded from each of these functions, but migration should be fairly
easy as the defaults operate over `String` which is a common type to use.
[breaking-change]
When projecting associate types for a trait's default methods, the
trait itself was added to the predicate candidate list twice: one from
parameter environment, the other from trait definition. Then the
duplicates were deemed as code ambiguity and the compiler rejected the
code. Simply checking and dropping the duplicates solves the issue.
Closes#22036
There are a number of holes that the stability lint did not previously cover,
including:
* Types
* Bounds on type parameters on functions and impls
* Where clauses
* Imports
* Patterns (structs and enums)
These holes have all been fixed by overriding the `visit_path` function on the
AST visitor instead of a few specialized cases. This change also necessitated a
few stability changes:
* The `collections::fmt` module is now stable (it was already supposed to be).
* The `thread_local:👿:Key` type is now stable (it was already supposed to
be).
* The `std::rt::{begin_unwind, begin_unwind_fmt}` functions are now stable.
These are required via the `panic!` macro.
* The `std::old_io::stdio::{println, println_args}` functions are now stable.
These are required by the `print!` and `println!` macros.
* The `ops::{FnOnce, FnMut, Fn}` traits are now `#[stable]`. This is required to
make bounds with these traits stable. Note that manual implementations of
these traits are still gated by default, this stability only allows bounds
such as `F: FnOnce()`.
Closes#8962Closes#16360Closes#20327
The live code analysis only visited the function's body when visiting a
method, and not the FnDecl and the generics, resulting in code to be
incorrectly marked as unused when it only appeared in the generics, the
arguments, or the return type, whereas the same code in non-method
functions was correctly detected as used. Fixes#20343.
Originally I just added a call to `walk_generics` and `walk_fndecl` alongside `walk_block` but then I noticed the `walk_method_helper` function did pretty much the same thing. The only difference is that it also calls `visit_mac`, but since this is not going to happen at this stage, I think it's ok. However let me know if this was not the right thing to do.
This renames the PrivateNoMangleFns lint to allow both to happen in a
single pass, since they do roughly the same work.
Closes#21856
Open questions:
[ ]: Do the tests actually pass (I'm running make check and running out the door now)
[ ]: Is the name of this lint ok. it seems to mostly be fine with [convention](cc53afbe5d/text/0344-conventions-galore.md (lints))
[ ]: I'm not super thrilled about the warning text
r? @kmcallister (Shamelessly nominating because you were looking at my other ticket)
This commit tweaks the interface of the `std::env` module to make it more
ergonomic for common usage:
* `env::var` was renamed to `env::var_os`
* `env::var_string` was renamed to `env::var`
* `env::args` was renamed to `env::args_os`
* `env::args` was re-added as a panicking iterator over string values
* `env::vars` was renamed to `env::vars_os`
* `env::vars` was re-added as a panicking iterator over string values.
This should make common usage (e.g. unicode values everywhere) more ergonomic
as well as "the default". This is also a breaking change due to the differences
of what's yielded from each of these functions, but migration should be fairly
easy as the defaults operate over `String` which is a common type to use.
[breaking-change]
There are a number of holes that the stability lint did not previously cover,
including:
* Types
* Bounds on type parameters on functions and impls
* Where clauses
* Imports
* Patterns (structs and enums)
These holes have all been fixed by overriding the `visit_path` function on the
AST visitor instead of a few specialized cases. This change also necessitated a
few stability changes:
* The `collections::fmt` module is now stable (it was already supposed to be).
* The `thread_local:👿:Key` type is now stable (it was already supposed to
be).
* The `std::rt::{begin_unwind, begin_unwind_fmt}` functions are now stable.
These are required via the `panic!` macro.
* The `std::old_io::stdio::{println, println_args}` functions are now stable.
These are required by the `print!` and `println!` macros.
* The `ops::{FnOnce, FnMut, Fn}` traits are now `#[stable]`. This is required to
make bounds with these traits stable. Note that manual implementations of
these traits are still gated by default, this stability only allows bounds
such as `F: FnOnce()`.
Additionally, the compiler now has special logic to ignore its own generated
`__test` module for the `--test` harness in terms of stability.
Closes#8962Closes#16360Closes#20327
[breaking-change]
This is a resurrection and heavy revision/expansion of a PR that pcwalton did to resolve#8861.
The most relevant, user-visible semantic change is this: #[unsafe_destructor] is gone. Instead, if a type expression for some value has a destructor, then any lifetimes referenced within that type expression must strictly outlive the scope of the value.
See discussion on https://github.com/rust-lang/rfcs/pull/769
When projecting associate types for a trait's default methods, the
trait itself was added to the predicate candidate list twice: one from
parameter environment, the other from trait definition. Then the
duplicates were deemed as code ambiguity and the compiler rejected the
code. Simply checking and dropping the duplicates solves the issue.
Closes#22036
Port `core::ptr::Unique` to have `PhantomData`. Add `PhantomData` to
`TypedArena` and `Vec` as well.
As a drive-by, switch `ptr::Unique` from a tuple-struct to a struct
with fields.
Largely adapted from pcwalton's original branch, with following
notable modifications:
Use `regionck::type_must_outlive` to generate `SafeDestructor`
constraints. (this plugged some soundness holes in the analysis).
Avoid exponential time blowup on compile-fail/huge-struct.rs by
keeping the breadcrumbs until end of traversal.
Avoid premature return from regionck::visit_expr.
Factored drop-checking code out into dropck module.
Added `SafeDestructor` to enum `SubregionOrigin` (for error reporting).
----
Since this imposes restrictions on the lifetimes used in types with
destructors, this is a (wait for it)
[breaking-change]
immediately surrounding a node that is a terminating_scope
(e.g. statements, looping forms) during which the destructors run (the
destructors for temporaries from the execution of that node, that is).
Introduced DestructionScopeData newtype wrapper around ast::NodeId, to
preserve invariant that FreeRegion and ScopeChain::BlockScope carry
destruction scopes (rather than arbitrary CodeExtents).
Insert DestructionScope and block Remainder into enclosing CodeExtents
hierarchy.
Add more doc for DestructionScope, complete with ASCII art.
Switch to constructing DestructionScope rather than Misc in a number
of places, mostly related to `ty::ReFree` creation, and use
destruction-scopes of node-ids at various calls to
liberate_late_bound_regions.
middle::resolve_lifetime: Map BlockScope to DestructionScope in `fn resolve_free_lifetime`.
Add the InnermostDeclaringBlock and InnermostEnclosingExpr enums that
are my attempt to clarify the region::Context structure, and that
later commmts build upon.
Improve the debug output for `CodeExtent` attached to `ty::Region::ReScope`.
Loosened an assertion in `rustc_trans::trans::cleanup` to account for
`DestructionScope`. (Perhaps this should just be switched entirely
over to `DestructionScope`, rather than allowing for either `Misc` or
`DestructionScope`.)
----
Even though the DestructionScope is new, this particular commit should
not actually change the semantics of any current code.
The live code analysis only visited the function's body when visiting a
method, and not the FnDecl and the generics, resulting in code to be
incorrectly marked as unused when it only appeared in the generics, the
arguments, or the return type, whereas the same code in non-method
functions was correctly detected as used. Fixes#20343.
Crate types from multiple sources appear to be deduplicated properly, but not
deduplicated if they come from the command line arguments. At worst, this used
to cause compiler failures when `--crate-type=lib,rlib` (the same as
`--crate-type=rlib,rlib`, at least at the time of this commit) is provided and
generate the output multiple times otherwise.
r? @alexcrichton
Rename several remaining `Show`s to Debug, `String`s to Display (mostly in comments and docs).
Update reference.md:
- derive() no longer supports Zero trait
- derive() now supports Copy trait
Simplify cache selection by just using the local cache whenever there
are any where-clauses at all. This seems to be the simplest possible
rule and will (hopefully!) put an end to these annoying "cache leak"
bugs. Fixes#22019.
r? @aturon
```rust
#[plugin] #[no_link] extern crate bleh;
```
becomes a crate attribute
```rust
#![plugin(bleh)]
```
The feature gate is still required.
It's almost never correct to link a plugin into the resulting library / executable, because it will bring all of libsyntax and librustc with it. However if you really want this behavior, you can get it with a separate `extern crate` item in addition to the `plugin` attribute.
Fixes#21043.
Fixes#20769.
[breaking-change]
#[plugin] #[no_link] extern crate bleh;
becomes a crate attribute
#![plugin(bleh)]
The feature gate is still required.
It's almost never correct to link a plugin into the resulting library /
executable, because it will bring all of libsyntax and librustc with it.
However if you really want this behavior, you can get it with a separate
`extern crate` item in addition to the `plugin` attribute.
Fixes#21043.
Fixes#20769.
[breaking-change]
Crate types from multiple sources appear to be deduplicated properly, but not
deduplicated if they come from the command line arguments. At worst, this used
to cause compiler failures when `--crate-type=lib,rlib` (the same as
`--crate-type=rlib,rlib`, at least at the time of this commit) is provided and
generate the output multiple times otherwise.
Revised version of PR #21930.
Restrictions on moves into and out-from fixed-length arrays.
(There was only one use of this "feature" in the compiler source.)
Note 1: the change to the error message in tests/compile-fail/borrowck-use-in-index-lvalue.rs, where we now report that *w is uninitialized (rather than w), was unintended fallout from the implementation strategy used here. The change appears harmless to me, but I welcome advice on how to bring back the old message, which was slightly cleaner (i.e. less unintelligible) since that the syntactic form *w does not actually appear in the source text.
Note 2: the move out-from restriction to only apply to expr[i], and not destructuring bind (e.g. f([a, b, c]: Array) { ... }) since the latter is compatible with nonzeroing drop, AFAICT.
[breaking-change]
No longer legal: `fn foo(a: [D; 5]) { drop(a); a[2] = D::new(); }`;
one must first initialize the entirety of `a` before assigning to its
individual elements.
No longer legal: `fn foo(arr: [D; 5]) -> D { arr[2] }`, unless `D`
implements `Copy`. This "move out-from" restriction only affects
`expr[i]`, and not destructuring (e.g. `f([a, b, c]: Array) { ... }`).
uses mem_categorization to distinguish destructuring-bind from array
indexing.
See discussion on RFC PR 533.
[breaking-change]
The compiler would previously fall back to using `-L` and normal lookup paths if
a `--extern` path was specified but it did not match (wrong architecture, for
example). This commit removes this behavior and forces the hand of the crate
loader to *always* use the `--extern` path if specified, no matter whether it is
correct or not.
This fixes a bug today where the compiler's own libraries are favored in cross
compilation by accident. For example when a crate using the crates.io version of
`log` was cross compiled, Cargo would compile `log` for the target architecture.
When loading the macros, however, the compiler currently favors using the *host*
architecture (for plugins), and because the `--extern log=...` pointed at an
rlib for the target architecture, that lookup failed. The crate loader then
fell back on `-L` paths to find the compiler-used `log` crate (the wrong one!)
and then a compile failure happened because the logging macros are slightly
different.
Add special error for this case and help message `please recompile this crate using --crate-type lib`, also list found candidates.
See issue #14416
r? @alexcrichton
