This commit stabilizes essentially all of the new `std::path` API. The
API itself is changed in a couple of ways (which brings it in closer
alignment with the RFC):
* `.` components are now normalized away, unless they appear at the
start of a path. This in turn effects the semantics of e.g. asking for
the file name of `foo/` or `foo/.`, both of which yield `Some("foo")`
now. This semantics is what the original RFC specified, and is also
desirable given early experience rolling out the new API.
* The `parent` method is now `without_file` and succeeds if, and only
if, `file_name` is `Some(_)`. That means, in particular, that it fails
for a path like `foo/../`. This change affects `pop` as well.
In addition, the `old_path` module is now deprecated.
[breaking-change]
r? @alexcrichton
This commit stabilizes essentially all of the new `std::path` API. The
API itself is changed in a couple of ways (which brings it in closer
alignment with the RFC):
* `.` components are now normalized away, unless they appear at the
start of a path. This in turn effects the semantics of e.g. asking for
the file name of `foo/` or `foo/.`, both of which yield `Some("foo")`
now. This semantics is what the original RFC specified, and is also
desirable given early experience rolling out the new API.
* The `parent` function now succeeds if, and only if, the path has at
least one non-root/prefix component. This change affects `pop` as
well.
* The `Prefix` component now involves a separate `PrefixComponent`
struct, to better allow for keeping both parsed and unparsed prefix data.
In addition, the `old_path` module is now deprecated.
Closes#23264
[breaking-change]
This is a hack, but I don't think we can do much better as long as `derive` is running at the syntax expansion phase.
If the `custom_derive` feature gate is enabled, this works with user-defined traits and syntax extensions. Without the gate, you can't use e.g. `#[derive_Clone]` directly, so this does not change the stable language.
To make this effective, we now check gated attributes both before and after macro expansion. This uncovered a number of tests that were missing feature gates.
This PR also cleans up the deriving code somewhat, and forbids some previously-meaningless attribute syntax. For this reason it's technically a
[breaking-change]
r? @sfackler
This is a hack, but I don't think we can do much better as long as `derive` is
running at the syntax expansion phase.
If the custom_derive feature gate is enabled, this works with user-defined
traits and syntax extensions. Without the gate, you can't use e.g. #[derive_Clone]
directly, so this does not change the stable language.
This commit also cleans up the deriving code somewhat, and forbids some
previously-meaningless attribute syntax. For this reason it's technically a
[breaking-change]
since there are separate checks that apply to Copy (and Send uses the
generic defaulted trait rules). Also prohibit `Sized` from being
manually implemented for now.
Unstable items used in a macro expansion will now always trigger
stability warnings, *unless* the unstable items are directly inside a
macro marked with `#[allow_internal_unstable]`. IOW, the compiler warns
unless the span of the unstable item is a subspan of the definition of a
macro marked with that attribute.
E.g.
#[allow_internal_unstable]
macro_rules! foo {
($e: expr) => {{
$e;
unstable(); // no warning
only_called_by_foo!();
}}
}
macro_rules! only_called_by_foo {
() => { unstable() } // warning
}
foo!(unstable()) // warning
The unstable inside `foo` is fine, due to the attribute. But the
`unstable` inside `only_called_by_foo` is not, since that macro doesn't
have the attribute, and the `unstable` passed into `foo` is also not
fine since it isn't contained in the macro itself (that is, even though
it is only used directly in the macro).
In the process this makes the stability tracking much more precise,
e.g. previously `println!("{}", unstable())` got no warning, but now it
does. As such, this is a bug fix that may cause [breaking-change]s.
The attribute is definitely feature gated, since it explicitly allows
side-stepping the feature gating system.
---
This updates `thread_local!` macro to use the attribute, since it uses
unstable features internally (initialising a struct with unstable
fields).
Unstable items used in a macro expansion will now always trigger
stability warnings, *unless* the unstable items are directly inside a
macro marked with `#[allow_internal_unstable]`. IOW, the compiler warns
unless the span of the unstable item is a subspan of the definition of a
macro marked with that attribute.
E.g.
#[allow_internal_unstable]
macro_rules! foo {
($e: expr) => {{
$e;
unstable(); // no warning
only_called_by_foo!();
}}
}
macro_rules! only_called_by_foo {
() => { unstable() } // warning
}
foo!(unstable()) // warning
The unstable inside `foo` is fine, due to the attribute. But the
`unstable` inside `only_called_by_foo` is not, since that macro doesn't
have the attribute, and the `unstable` passed into `foo` is also not
fine since it isn't contained in the macro itself (that is, even though
it is only used directly in the macro).
In the process this makes the stability tracking much more precise,
e.g. previously `println!(\"{}\", unstable())` got no warning, but now it
does. As such, this is a bug fix that may cause [breaking-change]s.
The attribute is definitely feature gated, since it explicitly allows
side-stepping the feature gating system.
---
This updates `thread_local!` macro to use the attribute, since it uses
unstable features internally (initialising a struct with unstable
fields).
Unstable items used in a macro expansion will now always trigger
stability warnings, *unless* the unstable items are directly inside a
macro marked with `#[allow_internal_unstable]`. IOW, the compiler warns
unless the span of the unstable item is a subspan of the definition of a
macro marked with that attribute.
E.g.
#[allow_internal_unstable]
macro_rules! foo {
($e: expr) => {{
$e;
unstable(); // no warning
only_called_by_foo!();
}}
}
macro_rules! only_called_by_foo {
() => { unstable() } // warning
}
foo!(unstable()) // warning
The unstable inside `foo` is fine, due to the attribute. But the
`unstable` inside `only_called_by_foo` is not, since that macro doesn't
have the attribute, and the `unstable` passed into `foo` is also not
fine since it isn't contained in the macro itself (that is, even though
it is only used directly in the macro).
In the process this makes the stability tracking much more precise,
e.g. previously `println!("{}", unstable())` got no warning, but now it
does. As such, this is a bug fix that may cause [breaking-change]s.
The attribute is definitely feature gated, since it explicitly allows
side-stepping the feature gating system.
This allows to create proper debuginfo line information for items inlined from other crates (e.g. instantiations of generics).
Only the codemap's 'metadata' is stored in a crate's metadata. That is, just filename, line-beginnings, etc. but not the actual source code itself. We are thus missing the opportunity of making Rust the first "open-source-only" programming language out there. Pity.
Many of the modifications putting in `Box::new` calls also include a
pointer to Issue 22405, which tracks going back to `box <expr>` if
possible in the future.
(Still tried to use `Box<_>` where it sufficed; thus some tests still
have `box_syntax` enabled, as they use a mix of `box` and `Box::new`.)
Precursor for overloaded-`box` and placement-`in`; see Issue 22181.
MacEager is a MacResult implementation for the common case where you've already built each form of AST that you might return.
Fixes#17637. Based on #18814.
This is a [breaking-change] for syntax extensions:
* MacExpr::new becomes MacEager::expr.
* MacPat::new becomes MacEager::pat.
* MacItems::new becomes MacEager::items. It takes a SmallVector directly,
not an iterator.
r? @sfackler
MacEager is a MacResult implementation for the common case where you've already
built each form of AST that you might return.
Fixes#17637. Based on #18814.
This is a [breaking-change] for syntax extensions:
* MacExpr::new becomes MacEager::expr.
* MacPat::new becomes MacEager::pat.
* MacItems::new becomes MacEager::items. It takes a SmallVector directly,
not an iterator.
We were recording stability attributes applied to fields in the
compiler, and even annotating it in the libs, but the compiler didn't
actually do the checks to give errors/warnings in user crates.
Names of structs, enums, traits, type aliases and type parameters (i.e. all identifiers that can be used as full paths in type position) are not allowed to match the names of primitive types.
See #20427 for more information.
This is a minor [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]
Makes the compilation abort when a parse error is encountered while
trying to parse an item in an included file. The previous behaviour was
to stop processing the file when a token that can't start an item was
encountered, without producing any error. Fixes#21146.
