From b2844917ad29e967043bea4e187421a6a3f61682 Mon Sep 17 00:00:00 2001 From: Edwin Cheng Date: Sat, 4 Apr 2020 16:04:01 +0800 Subject: Add proc_macro mod (copy from lib_proc_macro) --- crates/ra_proc_macro_srv/src/proc_macro/mod.rs | 926 +++++++++++++++++++++++++ 1 file changed, 926 insertions(+) create mode 100644 crates/ra_proc_macro_srv/src/proc_macro/mod.rs (limited to 'crates/ra_proc_macro_srv/src/proc_macro/mod.rs') diff --git a/crates/ra_proc_macro_srv/src/proc_macro/mod.rs b/crates/ra_proc_macro_srv/src/proc_macro/mod.rs new file mode 100644 index 000000000..e35a6ff8b --- /dev/null +++ b/crates/ra_proc_macro_srv/src/proc_macro/mod.rs @@ -0,0 +1,926 @@ +//! lib-proc-macro main module +//! +//! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/lib.rs +//! augmented with removing unstable features + +// NOTE(@edwin0cheng): +// Because we just copy the bridge module from rustc for ABI compatible +// There are some unused stuffs inside it. +// We suppress these warning here. +#[doc(hidden)] +#[allow(unused_macros)] +#[allow(unused_variables)] +pub mod bridge; + +mod diagnostic; + +pub use diagnostic::{Diagnostic, Level, MultiSpan}; + +use std::ops::{Bound, RangeBounds}; +use std::path::PathBuf; +use std::str::FromStr; +use std::{fmt, iter, mem}; + +/// The main type provided by this crate, representing an abstract stream of +/// tokens, or, more specifically, a sequence of token trees. +/// The type provide interfaces for iterating over those token trees and, conversely, +/// collecting a number of token trees into one stream. +/// +/// This is both the input and output of `#[proc_macro]`, `#[proc_macro_attribute]` +/// and `#[proc_macro_derive]` definitions. +#[derive(Clone)] +pub struct TokenStream(bridge::client::TokenStream); + +/// Error returned from `TokenStream::from_str` +#[derive(Debug)] +pub struct LexError { + _inner: (), +} + +impl TokenStream { + /// Returns an empty `TokenStream` containing no token trees. + pub fn new() -> TokenStream { + TokenStream(bridge::client::TokenStream::new()) + } + + /// Checks if this `TokenStream` is empty. + pub fn is_empty(&self) -> bool { + self.0.is_empty() + } +} + +/// Attempts to break the string into tokens and parse those tokens into a token stream. +/// May fail for a number of reasons, for example, if the string contains unbalanced delimiters +/// or characters not existing in the language. +/// All tokens in the parsed stream get `Span::call_site()` spans. +/// +/// NOTE: some errors may cause panics instead of returning `LexError`. We reserve the right to +/// change these errors into `LexError`s later. +impl FromStr for TokenStream { + type Err = LexError; + + fn from_str(src: &str) -> Result { + Ok(TokenStream(bridge::client::TokenStream::from_str(src))) + } +} + +// N.B., the bridge only provides `to_string`, implement `fmt::Display` +// based on it (the reverse of the usual relationship between the two). +// impl ToString for TokenStream { +// fn to_string(&self) -> String { +// self.0.to_string() +// } +// } + +/// Prints the token stream as a string that is supposed to be losslessly convertible back +/// into the same token stream (modulo spans), except for possibly `TokenTree::Group`s +/// with `Delimiter::None` delimiters and negative numeric literals. +impl fmt::Display for TokenStream { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str(&self.to_string()) + } +} + +/// Prints token in a form convenient for debugging. +impl fmt::Debug for TokenStream { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str("TokenStream ")?; + f.debug_list().entries(self.clone()).finish() + } +} + +/// Creates a token stream containing a single token tree. +impl From for TokenStream { + fn from(tree: TokenTree) -> TokenStream { + TokenStream(bridge::client::TokenStream::from_token_tree(match tree { + TokenTree::Group(tt) => bridge::TokenTree::Group(tt.0), + TokenTree::Punct(tt) => bridge::TokenTree::Punct(tt.0), + TokenTree::Ident(tt) => bridge::TokenTree::Ident(tt.0), + TokenTree::Literal(tt) => bridge::TokenTree::Literal(tt.0), + })) + } +} + +/// Collects a number of token trees into a single stream. +impl iter::FromIterator for TokenStream { + fn from_iter>(trees: I) -> Self { + trees.into_iter().map(TokenStream::from).collect() + } +} + +/// A "flattening" operation on token streams, collects token trees +/// from multiple token streams into a single stream. +impl iter::FromIterator for TokenStream { + fn from_iter>(streams: I) -> Self { + let mut builder = bridge::client::TokenStreamBuilder::new(); + streams.into_iter().for_each(|stream| builder.push(stream.0)); + TokenStream(builder.build()) + } +} + +impl Extend for TokenStream { + fn extend>(&mut self, trees: I) { + self.extend(trees.into_iter().map(TokenStream::from)); + } +} + +impl Extend for TokenStream { + fn extend>(&mut self, streams: I) { + // FIXME(eddyb) Use an optimized implementation if/when possible. + *self = iter::once(mem::replace(self, Self::new())).chain(streams).collect(); + } +} + +/// Public implementation details for the `TokenStream` type, such as iterators. +pub mod token_stream { + use crate::proc_macro::{bridge, Group, Ident, Literal, Punct, TokenStream, TokenTree}; + + /// An iterator over `TokenStream`'s `TokenTree`s. + /// The iteration is "shallow", e.g., the iterator doesn't recurse into delimited groups, + /// and returns whole groups as token trees. + #[derive(Clone)] + pub struct IntoIter(bridge::client::TokenStreamIter); + + impl Iterator for IntoIter { + type Item = TokenTree; + + fn next(&mut self) -> Option { + self.0.next().map(|tree| match tree { + bridge::TokenTree::Group(tt) => TokenTree::Group(Group(tt)), + bridge::TokenTree::Punct(tt) => TokenTree::Punct(Punct(tt)), + bridge::TokenTree::Ident(tt) => TokenTree::Ident(Ident(tt)), + bridge::TokenTree::Literal(tt) => TokenTree::Literal(Literal(tt)), + }) + } + } + + impl IntoIterator for TokenStream { + type Item = TokenTree; + type IntoIter = IntoIter; + + fn into_iter(self) -> IntoIter { + IntoIter(self.0.into_iter()) + } + } +} + +/// A region of source code, along with macro expansion information. +#[derive(Copy, Clone)] +pub struct Span(bridge::client::Span); + +macro_rules! diagnostic_method { + ($name:ident, $level:expr) => ( + /// Creates a new `Diagnostic` with the given `message` at the span + /// `self`. + pub fn $name>(self, message: T) -> Diagnostic { + Diagnostic::spanned(self, $level, message) + } + ) +} + +impl Span { + /// A span that resolves at the macro definition site. + pub fn def_site() -> Span { + Span(bridge::client::Span::def_site()) + } + + /// The span of the invocation of the current procedural macro. + /// Identifiers created with this span will be resolved as if they were written + /// directly at the macro call location (call-site hygiene) and other code + /// at the macro call site will be able to refer to them as well. + pub fn call_site() -> Span { + Span(bridge::client::Span::call_site()) + } + + /// A span that represents `macro_rules` hygiene, and sometimes resolves at the macro + /// definition site (local variables, labels, `$crate`) and sometimes at the macro + /// call site (everything else). + /// The span location is taken from the call-site. + pub fn mixed_site() -> Span { + Span(bridge::client::Span::mixed_site()) + } + + /// The original source file into which this span points. + pub fn source_file(&self) -> SourceFile { + SourceFile(self.0.source_file()) + } + + /// The `Span` for the tokens in the previous macro expansion from which + /// `self` was generated from, if any. + pub fn parent(&self) -> Option { + self.0.parent().map(Span) + } + + /// The span for the origin source code that `self` was generated from. If + /// this `Span` wasn't generated from other macro expansions then the return + /// value is the same as `*self`. + pub fn source(&self) -> Span { + Span(self.0.source()) + } + + /// Gets the starting line/column in the source file for this span. + pub fn start(&self) -> LineColumn { + self.0.start() + } + + /// Gets the ending line/column in the source file for this span. + pub fn end(&self) -> LineColumn { + self.0.end() + } + + /// Creates a new span encompassing `self` and `other`. + /// + /// Returns `None` if `self` and `other` are from different files. + pub fn join(&self, other: Span) -> Option { + self.0.join(other.0).map(Span) + } + + /// Creates a new span with the same line/column information as `self` but + /// that resolves symbols as though it were at `other`. + 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`. + pub fn located_at(&self, other: Span) -> Span { + other.resolved_at(*self) + } + + /// Compares to spans to see if they're equal. + pub fn eq(&self, other: &Span) -> bool { + self.0 == other.0 + } + + /// Returns the source text behind a span. This preserves the original source + /// code, including spaces and comments. It only returns a result if the span + /// corresponds to real source code. + /// + /// Note: The observable result of a macro should only rely on the tokens and + /// not on this source text. The result of this function is a best effort to + /// be used for diagnostics only. + pub fn source_text(&self) -> Option { + self.0.source_text() + } + + diagnostic_method!(error, Level::Error); + diagnostic_method!(warning, Level::Warning); + diagnostic_method!(note, Level::Note); + diagnostic_method!(help, Level::Help); +} + +/// Prints a span in a form convenient for debugging. +impl fmt::Debug for Span { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.0.fmt(f) + } +} + +/// A line-column pair representing the start or end of a `Span`. +#[derive(Copy, Clone, Debug, PartialEq, Eq)] +pub struct LineColumn { + /// The 1-indexed line in the source file on which the span starts or ends (inclusive). + pub line: usize, + /// The 0-indexed column (in UTF-8 characters) in the source file on which + /// the span starts or ends (inclusive). + pub column: usize, +} + +/// The source file of a given `Span`. +#[derive(Clone)] +pub struct SourceFile(bridge::client::SourceFile); + +impl SourceFile { + /// Gets the path to this source file. + /// + /// ### Note + /// If the code span associated with this `SourceFile` was generated by an external macro, this + /// macro, this may not be an actual path on the filesystem. Use [`is_real`] to check. + /// + /// Also note that even if `is_real` returns `true`, if `--remap-path-prefix` was passed on + /// the command line, the path as given may not actually be valid. + /// + /// [`is_real`]: #method.is_real + pub fn path(&self) -> PathBuf { + PathBuf::from(self.0.path()) + } + + /// Returns `true` if this source file is a real source file, and not generated by an external + /// macro's expansion. + pub fn is_real(&self) -> bool { + // This is a hack until intercrate spans are implemented and we can have real source files + // for spans generated in external macros. + // https://github.com/rust-lang/rust/pull/43604#issuecomment-333334368 + self.0.is_real() + } +} + +impl fmt::Debug for SourceFile { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("SourceFile") + .field("path", &self.path()) + .field("is_real", &self.is_real()) + .finish() + } +} + +impl PartialEq for SourceFile { + fn eq(&self, other: &Self) -> bool { + self.0.eq(&other.0) + } +} + +impl Eq for SourceFile {} + +/// A single token or a delimited sequence of token trees (e.g., `[1, (), ..]`). +#[derive(Clone)] +pub enum TokenTree { + /// A token stream surrounded by bracket delimiters. + Group(Group), + /// An identifier. + Ident(Ident), + /// A single punctuation character (`+`, `,`, `$`, etc.). + Punct(Punct), + /// A literal character (`'a'`), string (`"hello"`), number (`2.3`), etc. + Literal(Literal), +} + +impl TokenTree { + /// Returns the span of this tree, delegating to the `span` method of + /// the contained token or a delimited stream. + pub fn span(&self) -> Span { + match *self { + TokenTree::Group(ref t) => t.span(), + TokenTree::Ident(ref t) => t.span(), + TokenTree::Punct(ref t) => t.span(), + TokenTree::Literal(ref t) => t.span(), + } + } + + /// Configures the span for *only this token*. + /// + /// Note that if this token is a `Group` then this method will not configure + /// the span of each of the internal tokens, this will simply delegate to + /// the `set_span` method of each variant. + pub fn set_span(&mut self, span: Span) { + match *self { + TokenTree::Group(ref mut t) => t.set_span(span), + TokenTree::Ident(ref mut t) => t.set_span(span), + TokenTree::Punct(ref mut t) => t.set_span(span), + TokenTree::Literal(ref mut t) => t.set_span(span), + } + } +} + +/// Prints token tree in a form convenient for debugging. +impl fmt::Debug for TokenTree { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + // Each of these has the name in the struct type in the derived debug, + // so don't bother with an extra layer of indirection + match *self { + TokenTree::Group(ref tt) => tt.fmt(f), + TokenTree::Ident(ref tt) => tt.fmt(f), + TokenTree::Punct(ref tt) => tt.fmt(f), + TokenTree::Literal(ref tt) => tt.fmt(f), + } + } +} + +impl From for TokenTree { + fn from(g: Group) -> TokenTree { + TokenTree::Group(g) + } +} + +impl From for TokenTree { + fn from(g: Ident) -> TokenTree { + TokenTree::Ident(g) + } +} + +impl From for TokenTree { + fn from(g: Punct) -> TokenTree { + TokenTree::Punct(g) + } +} + +impl From for TokenTree { + fn from(g: Literal) -> TokenTree { + TokenTree::Literal(g) + } +} + +// N.B., the bridge only provides `to_string`, implement `fmt::Display` +// based on it (the reverse of the usual relationship between the two). +// impl ToString for TokenTree { +// fn to_string(&self) -> String { +// match *self { +// TokenTree::Group(ref t) => t.to_string(), +// TokenTree::Ident(ref t) => t.to_string(), +// TokenTree::Punct(ref t) => t.to_string(), +// TokenTree::Literal(ref t) => t.to_string(), +// } +// } +// } + +/// Prints the token tree as a string that is supposed to be losslessly convertible back +/// into the same token tree (modulo spans), except for possibly `TokenTree::Group`s +/// with `Delimiter::None` delimiters and negative numeric literals. +impl fmt::Display for TokenTree { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str(&self.to_string()) + } +} + +/// A delimited token stream. +/// +/// A `Group` internally contains a `TokenStream` which is surrounded by `Delimiter`s. +#[derive(Clone)] +pub struct Group(bridge::client::Group); + +/// Describes how a sequence of token trees is delimited. +#[derive(Copy, Clone, Debug, PartialEq, Eq)] +pub enum Delimiter { + /// `( ... )` + Parenthesis, + /// `{ ... }` + Brace, + /// `[ ... ]` + Bracket, + /// `Ø ... Ø` + /// An implicit delimiter, that may, for example, appear around tokens coming from a + /// "macro variable" `$var`. It is important to preserve operator priorities in cases like + /// `$var * 3` where `$var` is `1 + 2`. + /// Implicit delimiters may not survive roundtrip of a token stream through a string. + None, +} + +impl Group { + /// Creates a new `Group` with the given delimiter and token stream. + /// + /// This constructor will set the span for this group to + /// `Span::call_site()`. To change the span you can use the `set_span` + /// method below. + pub fn new(delimiter: Delimiter, stream: TokenStream) -> Group { + Group(bridge::client::Group::new(delimiter, stream.0)) + } + + /// Returns the delimiter of this `Group` + pub fn delimiter(&self) -> Delimiter { + self.0.delimiter() + } + + /// Returns the `TokenStream` of tokens that are delimited in this `Group`. + /// + /// Note that the returned token stream does not include the delimiter + /// returned above. + pub fn stream(&self) -> TokenStream { + TokenStream(self.0.stream()) + } + + /// Returns the span for the delimiters of this token stream, spanning the + /// entire `Group`. + /// + /// ```text + /// pub fn span(&self) -> Span { + /// ^^^^^^^ + /// ``` + pub fn span(&self) -> Span { + Span(self.0.span()) + } + + /// Returns the span pointing to the opening delimiter of this group. + /// + /// ```text + /// pub fn span_open(&self) -> Span { + /// ^ + /// ``` + pub fn span_open(&self) -> Span { + Span(self.0.span_open()) + } + + /// Returns the span pointing to the closing delimiter of this group. + /// + /// ```text + /// pub fn span_close(&self) -> Span { + /// ^ + /// ``` + pub fn span_close(&self) -> Span { + Span(self.0.span_close()) + } + + /// Configures the span for this `Group`'s delimiters, but not its internal + /// tokens. + /// + /// This method will **not** set the span of all the internal tokens spanned + /// by this group, but rather it will only set the span of the delimiter + /// tokens at the level of the `Group`. + pub fn set_span(&mut self, span: Span) { + self.0.set_span(span.0); + } +} + +// N.B., the bridge only provides `to_string`, implement `fmt::Display` +// based on it (the reverse of the usual relationship between the two). +// impl ToString for Group { +// fn to_string(&self) -> String { +// TokenStream::from(TokenTree::from(self.clone())).to_string() +// } +// } + +/// Prints the group as a string that should be losslessly convertible back +/// into the same group (modulo spans), except for possibly `TokenTree::Group`s +/// with `Delimiter::None` delimiters. +impl fmt::Display for Group { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str(&self.to_string()) + } +} + +impl fmt::Debug for Group { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("Group") + .field("delimiter", &self.delimiter()) + .field("stream", &self.stream()) + .field("span", &self.span()) + .finish() + } +} + +/// An `Punct` is an single punctuation character like `+`, `-` or `#`. +/// +/// Multi-character operators like `+=` are represented as two instances of `Punct` with different +/// forms of `Spacing` returned. +#[derive(Clone)] +pub struct Punct(bridge::client::Punct); + +/// Whether an `Punct` is followed immediately by another `Punct` or +/// followed by another token or whitespace. +#[derive(Copy, Clone, Debug, PartialEq, Eq)] +pub enum Spacing { + /// e.g., `+` is `Alone` in `+ =`, `+ident` or `+()`. + Alone, + /// e.g., `+` is `Joint` in `+=` or `'#`. + /// Additionally, single quote `'` can join with identifiers to form lifetimes `'ident`. + Joint, +} + +impl Punct { + /// Creates a new `Punct` from the given character and spacing. + /// The `ch` argument must be a valid punctuation character permitted by the language, + /// otherwise the function will panic. + /// + /// The returned `Punct` will have the default span of `Span::call_site()` + /// which can be further configured with the `set_span` method below. + pub fn new(ch: char, spacing: Spacing) -> Punct { + Punct(bridge::client::Punct::new(ch, spacing)) + } + + /// Returns the value of this punctuation character as `char`. + pub fn as_char(&self) -> char { + self.0.as_char() + } + + /// Returns the spacing of this punctuation character, indicating whether it's immediately + /// followed by another `Punct` in the token stream, so they can potentially be combined into + /// a multi-character operator (`Joint`), or it's followed by some other token or whitespace + /// (`Alone`) so the operator has certainly ended. + pub fn spacing(&self) -> Spacing { + self.0.spacing() + } + + /// Returns the span for this punctuation character. + pub fn span(&self) -> Span { + Span(self.0.span()) + } + + /// Configure the span for this punctuation character. + pub fn set_span(&mut self, span: Span) { + self.0 = self.0.with_span(span.0); + } +} + +// N.B., the bridge only provides `to_string`, implement `fmt::Display` +// based on it (the reverse of the usual relationship between the two). +// impl ToString for Punct { +// fn to_string(&self) -> String { +// TokenStream::from(TokenTree::from(self.clone())).to_string() +// } +// } + +/// Prints the punctuation character as a string that should be losslessly convertible +/// back into the same character. +impl fmt::Display for Punct { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str(&self.to_string()) + } +} + +impl fmt::Debug for Punct { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("Punct") + .field("ch", &self.as_char()) + .field("spacing", &self.spacing()) + .field("span", &self.span()) + .finish() + } +} + +/// An identifier (`ident`). +#[derive(Clone, PartialEq, Eq, Hash)] +pub struct Ident(bridge::client::Ident); + +impl Ident { + /// Creates a new `Ident` with the given `string` as well as the specified + /// `span`. + /// The `string` argument must be a valid identifier permitted by the + /// language, otherwise the function will panic. + /// + /// Note that `span`, currently in rustc, configures the hygiene information + /// for this identifier. + /// + /// As of this time `Span::call_site()` explicitly opts-in to "call-site" hygiene + /// meaning that identifiers created with this span will be resolved as if they were written + /// directly at the location of the macro call, and other code at the macro call site will be + /// able to refer to them as well. + /// + /// Later spans like `Span::def_site()` will allow to opt-in to "definition-site" hygiene + /// meaning that identifiers created with this span will be resolved at the location of the + /// macro definition and other code at the macro call site will not be able to refer to them. + /// + /// Due to the current importance of hygiene this constructor, unlike other + /// tokens, requires a `Span` to be specified at construction. + pub fn new(string: &str, span: Span) -> Ident { + Ident(bridge::client::Ident::new(string, span.0, false)) + } + + /// Same as `Ident::new`, but creates a raw identifier (`r#ident`). + pub fn new_raw(string: &str, span: Span) -> Ident { + Ident(bridge::client::Ident::new(string, span.0, true)) + } + + /// Returns the span of this `Ident`, encompassing the entire string returned + /// by `as_str`. + pub fn span(&self) -> Span { + Span(self.0.span()) + } + + /// Configures the span of this `Ident`, possibly changing its hygiene context. + pub fn set_span(&mut self, span: Span) { + self.0 = self.0.with_span(span.0); + } +} + +// N.B., the bridge only provides `to_string`, implement `fmt::Display` +// based on it (the reverse of the usual relationship between the two). +// impl ToString for Ident { +// fn to_string(&self) -> String { +// TokenStream::from(TokenTree::from(self.clone())).to_string() +// } +// } + +/// Prints the identifier as a string that should be losslessly convertible +/// back into the same identifier. +impl fmt::Display for Ident { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str(&self.to_string()) + } +} + +impl fmt::Debug for Ident { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("Ident") + .field("ident", &self.to_string()) + .field("span", &self.span()) + .finish() + } +} + +/// A literal string (`"hello"`), byte string (`b"hello"`), +/// character (`'a'`), byte character (`b'a'`), an integer or floating point number +/// with or without a suffix (`1`, `1u8`, `2.3`, `2.3f32`). +/// Boolean literals like `true` and `false` do not belong here, they are `Ident`s. +#[derive(Clone)] +pub struct Literal(bridge::client::Literal); + +macro_rules! suffixed_int_literals { + ($($name:ident => $kind:ident,)*) => ($( + /// Creates a new suffixed integer literal with the specified value. + /// + /// This function will create an integer like `1u32` where the integer + /// value specified is the first part of the token and the integral is + /// also suffixed at the end. + /// Literals created from negative numbers may not survive round-trips through + /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal). + /// + /// Literals created through this method have the `Span::call_site()` + /// span by default, which can be configured with the `set_span` method + /// below. + pub fn $name(n: $kind) -> Literal { + Literal(bridge::client::Literal::typed_integer(&n.to_string(), stringify!($kind))) + } + )*) +} + +macro_rules! unsuffixed_int_literals { + ($($name:ident => $kind:ident,)*) => ($( + /// Creates a new unsuffixed integer literal with the specified value. + /// + /// This function will create an integer like `1` where the integer + /// value specified is the first part of the token. No suffix is + /// specified on this token, meaning that invocations like + /// `Literal::i8_unsuffixed(1)` are equivalent to + /// `Literal::u32_unsuffixed(1)`. + /// Literals created from negative numbers may not survive rountrips through + /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal). + /// + /// Literals created through this method have the `Span::call_site()` + /// span by default, which can be configured with the `set_span` method + /// below. + pub fn $name(n: $kind) -> Literal { + Literal(bridge::client::Literal::integer(&n.to_string())) + } + )*) +} + +impl Literal { + suffixed_int_literals! { + u8_suffixed => u8, + u16_suffixed => u16, + u32_suffixed => u32, + u64_suffixed => u64, + u128_suffixed => u128, + usize_suffixed => usize, + i8_suffixed => i8, + i16_suffixed => i16, + i32_suffixed => i32, + i64_suffixed => i64, + i128_suffixed => i128, + isize_suffixed => isize, + } + + unsuffixed_int_literals! { + u8_unsuffixed => u8, + u16_unsuffixed => u16, + u32_unsuffixed => u32, + u64_unsuffixed => u64, + u128_unsuffixed => u128, + usize_unsuffixed => usize, + i8_unsuffixed => i8, + i16_unsuffixed => i16, + i32_unsuffixed => i32, + i64_unsuffixed => i64, + i128_unsuffixed => i128, + isize_unsuffixed => isize, + } + + /// Creates a new unsuffixed floating-point literal. + /// + /// This constructor is similar to those like `Literal::i8_unsuffixed` where + /// the float's value is emitted directly into the token but no suffix is + /// used, so it may be inferred to be a `f64` later in the compiler. + /// Literals created from negative numbers may not survive rountrips through + /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal). + /// + /// # Panics + /// + /// This function requires that the specified float is finite, for + /// example if it is infinity or NaN this function will panic. + pub fn f32_unsuffixed(n: f32) -> Literal { + if !n.is_finite() { + panic!("Invalid float literal {}", n); + } + Literal(bridge::client::Literal::float(&n.to_string())) + } + + /// Creates a new suffixed floating-point literal. + /// + /// This constructor will create a literal like `1.0f32` where the value + /// specified is the preceding part of the token and `f32` is the suffix of + /// the token. This token will always be inferred to be an `f32` in the + /// compiler. + /// Literals created from negative numbers may not survive rountrips through + /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal). + /// + /// # Panics + /// + /// This function requires that the specified float is finite, for + /// example if it is infinity or NaN this function will panic. + pub fn f32_suffixed(n: f32) -> Literal { + if !n.is_finite() { + panic!("Invalid float literal {}", n); + } + Literal(bridge::client::Literal::f32(&n.to_string())) + } + + /// Creates a new unsuffixed floating-point literal. + /// + /// This constructor is similar to those like `Literal::i8_unsuffixed` where + /// the float's value is emitted directly into the token but no suffix is + /// used, so it may be inferred to be a `f64` later in the compiler. + /// Literals created from negative numbers may not survive rountrips through + /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal). + /// + /// # Panics + /// + /// This function requires that the specified float is finite, for + /// example if it is infinity or NaN this function will panic. + pub fn f64_unsuffixed(n: f64) -> Literal { + if !n.is_finite() { + panic!("Invalid float literal {}", n); + } + Literal(bridge::client::Literal::float(&n.to_string())) + } + + /// Creates a new suffixed floating-point literal. + /// + /// This constructor will create a literal like `1.0f64` where the value + /// specified is the preceding part of the token and `f64` is the suffix of + /// the token. This token will always be inferred to be an `f64` in the + /// compiler. + /// Literals created from negative numbers may not survive rountrips through + /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal). + /// + /// # Panics + /// + /// This function requires that the specified float is finite, for + /// example if it is infinity or NaN this function will panic. + pub fn f64_suffixed(n: f64) -> Literal { + if !n.is_finite() { + panic!("Invalid float literal {}", n); + } + Literal(bridge::client::Literal::f64(&n.to_string())) + } + + /// String literal. + pub fn string(string: &str) -> Literal { + Literal(bridge::client::Literal::string(string)) + } + + /// Character literal. + pub fn character(ch: char) -> Literal { + Literal(bridge::client::Literal::character(ch)) + } + + /// Byte string literal. + pub fn byte_string(bytes: &[u8]) -> Literal { + Literal(bridge::client::Literal::byte_string(bytes)) + } + + /// Returns the span encompassing this literal. + pub fn span(&self) -> Span { + Span(self.0.span()) + } + + /// Configures the span associated for this literal. + pub fn set_span(&mut self, span: Span) { + self.0.set_span(span.0); + } + + /// Returns a `Span` that is a subset of `self.span()` containing only the + /// source bytes in range `range`. Returns `None` if the would-be trimmed + /// span is outside the bounds of `self`. + // FIXME(SergioBenitez): check that the byte range starts and ends at a + // UTF-8 boundary of the source. otherwise, it's likely that a panic will + // occur elsewhere when the source text is printed. + // FIXME(SergioBenitez): there is no way for the user to know what + // `self.span()` actually maps to, so this method can currently only be + // called blindly. For example, `to_string()` for the character 'c' returns + // "'\u{63}'"; there is no way for the user to know whether the source text + // was 'c' or whether it was '\u{63}'. + pub fn subspan>(&self, range: R) -> Option { + // HACK(eddyb) something akin to `Option::cloned`, but for `Bound<&T>`. + fn cloned_bound(bound: Bound<&T>) -> Bound { + match bound { + Bound::Included(x) => Bound::Included(x.clone()), + Bound::Excluded(x) => Bound::Excluded(x.clone()), + Bound::Unbounded => Bound::Unbounded, + } + } + + self.0.subspan(cloned_bound(range.start_bound()), cloned_bound(range.end_bound())).map(Span) + } +} + +// N.B., the bridge only provides `to_string`, implement `fmt::Display` +// based on it (the reverse of the usual relationship between the two). +// impl ToString for Literal { +// fn to_string(&self) -> String { +// TokenStream::from(TokenTree::from(self.clone())).to_string() +// } +// } + +/// Prints the literal as a string that should be losslessly convertible +/// back into the same literal (except for possible rounding for floating point literals). +impl fmt::Display for Literal { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str(&self.to_string()) + } +} + +impl fmt::Debug for Literal { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + // FIXME(eddyb) `Literal` should not expose internal `Debug` impls. + self.0.fmt(f) + } +} -- cgit v1.2.3