diff options
Diffstat (limited to 'src/libproc_macro/lib.rs')
| -rw-r--r-- | src/libproc_macro/lib.rs | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/src/libproc_macro/lib.rs b/src/libproc_macro/lib.rs index c51db695a5b..31bc61263ab 100644 --- a/src/libproc_macro/lib.rs +++ b/src/libproc_macro/lib.rs @@ -24,9 +24,10 @@ #![feature(decl_macro)] #![feature(extern_types)] #![feature(in_band_lifetimes)] +#![feature(negative_impls)] #![feature(optin_builtin_traits)] #![feature(rustc_attrs)] -#![feature(specialization)] +#![feature(min_specialization)] #![recursion_limit = "256"] #[unstable(feature = "proc_macro_internals", issue = "27812")] @@ -41,7 +42,25 @@ pub use diagnostic::{Diagnostic, Level, MultiSpan}; use std::ops::{Bound, RangeBounds}; use std::path::PathBuf; use std::str::FromStr; -use std::{fmt, iter, mem}; +use std::{error, fmt, iter, mem}; + +/// Determines whether proc_macro has been made accessible to the currently +/// running program. +/// +/// The proc_macro crate is only intended for use inside the implementation of +/// procedural macros. All the functions in this crate panic if invoked from +/// outside of a procedural macro, such as from a build script or unit test or +/// ordinary Rust binary. +/// +/// With consideration for Rust libraries that are designed to support both +/// macro and non-macro use cases, `proc_macro::is_available()` provides a +/// non-panicking way to detect whether the infrastructure required to use the +/// API of proc_macro is presently available. Returns true if invoked from +/// inside of a procedural macro, false if invoked from any other binary. +#[unstable(feature = "proc_macro_is_available", issue = "71436")] +pub fn is_available() -> bool { + bridge::Bridge::is_available() +} /// The main type provided by this crate, representing an abstract stream of /// tokens, or, more specifically, a sequence of token trees. @@ -66,6 +85,16 @@ pub struct LexError { _inner: (), } +#[stable(feature = "proc_macro_lexerror_impls", since = "1.44.0")] +impl fmt::Display for LexError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str("cannot parse string into token stream") + } +} + +#[stable(feature = "proc_macro_lexerror_impls", since = "1.44.0")] +impl error::Error for LexError {} + #[stable(feature = "proc_macro_lib", since = "1.15.0")] impl !Send for LexError {} #[stable(feature = "proc_macro_lib", since = "1.15.0")] @@ -244,14 +273,14 @@ impl !Send for Span {} impl !Sync for Span {} macro_rules! diagnostic_method { - ($name:ident, $level:expr) => ( + ($name:ident, $level:expr) => { /// Creates a new `Diagnostic` with the given `message` at the span /// `self`. #[unstable(feature = "proc_macro_diagnostic", issue = "54140")] pub fn $name<T: Into<String>>(self, message: T) -> Diagnostic { Diagnostic::spanned(self, $level, message) } - ) + }; } impl Span { @@ -274,7 +303,7 @@ impl Span { /// definition site (local variables, labels, `$crate`) and sometimes at the macro /// call site (everything else). /// The span location is taken from the call-site. - #[unstable(feature = "proc_macro_mixed_site", issue = "65049")] + #[stable(feature = "proc_macro_mixed_site", since = "1.45.0")] pub fn mixed_site() -> Span { Span(bridge::client::Span::mixed_site()) } @@ -322,14 +351,14 @@ impl Span { /// Creates a new span with the same line/column information as `self` but /// that resolves symbols as though it were at `other`. - #[unstable(feature = "proc_macro_span", issue = "54725")] + #[stable(feature = "proc_macro_span_resolved_at", since = "1.45.0")] pub fn resolved_at(&self, other: Span) -> Span { Span(self.0.resolved_at(other.0)) } /// Creates a new span with the same name resolution behavior as `self` but /// with the line/column information of `other`. - #[unstable(feature = "proc_macro_span", issue = "54725")] + #[stable(feature = "proc_macro_span_located_at", since = "1.45.0")] pub fn located_at(&self, other: Span) -> Span { other.resolved_at(*self) } |