#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
pub use diagnostic::{Diagnostic, Level, MultiSpan};
+use std::ops::{Bound, RangeBounds};
use std::{ascii, fmt, iter};
use std::path::PathBuf;
use rustc_data_structures::sync::Lrc;
use syntax::parse::{self, token};
use syntax::symbol::Symbol;
use syntax::tokenstream::{self, DelimSpan};
-use syntax_pos::{Pos, FileName};
+use syntax_pos::{Pos, FileName, BytePos};
/// The main type provided by this crate, representing an abstract stream of
/// tokens, or, more specifically, a sequence of token trees.
pub fn set_span(&mut self, span: Span) {
self.span = span;
}
+
+ /// 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}'.
+ #[unstable(feature = "proc_macro_span", issue = "54725")]
+ pub fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> {
+ let inner = self.span().0;
+ let length = inner.hi().to_usize() - inner.lo().to_usize();
+
+ let start = match range.start_bound() {
+ Bound::Included(&lo) => lo,
+ Bound::Excluded(&lo) => lo + 1,
+ Bound::Unbounded => 0,
+ };
+
+ let end = match range.end_bound() {
+ Bound::Included(&hi) => hi + 1,
+ Bound::Excluded(&hi) => hi,
+ Bound::Unbounded => length,
+ };
+
+ // Bounds check the values, preventing addition overflow and OOB spans.
+ if start > u32::max_value() as usize
+ || end > u32::max_value() as usize
+ || (u32::max_value() - start as u32) < inner.lo().to_u32()
+ || (u32::max_value() - end as u32) < inner.lo().to_u32()
+ || start >= end
+ || end > length
+ {
+ return None;
+ }
+
+ let new_lo = inner.lo() + BytePos::from_usize(start);
+ let new_hi = inner.lo() + BytePos::from_usize(end);
+ Some(Span(inner.with_lo(new_lo).with_hi(new_hi)))
+ }
}
/// Prints the literal as a string that should be losslessly convertible
--- /dev/null
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+#![feature(proc_macro_diagnostic, proc_macro_span)]
+
+extern crate proc_macro;
+
+use proc_macro::{TokenStream, TokenTree, Span, Diagnostic};
+
+fn parse(input: TokenStream) -> Result<(), Diagnostic> {
+ if let Some(TokenTree::Literal(lit)) = input.into_iter().next() {
+ let mut spans = vec![];
+ let string = lit.to_string();
+ for hi in string.matches("hi") {
+ let index = hi.as_ptr() as usize - string.as_ptr() as usize;
+ let subspan = lit.subspan(index..(index + hi.len())).unwrap();
+ spans.push(subspan);
+ }
+
+ if !spans.is_empty() {
+ Err(Span::call_site().error("found 'hi's").span_note(spans, "here"))
+ } else {
+ Ok(())
+ }
+ } else {
+ Err(Span::call_site().error("invalid input: expected string literal"))
+ }
+}
+
+#[proc_macro]
+pub fn subspan(input: TokenStream) -> TokenStream {
+ if let Err(diag) = parse(input) {
+ diag.emit();
+ }
+
+ TokenStream::new()
+}
--- /dev/null
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// aux-build:subspan.rs
+// ignore-stage1
+
+extern crate subspan;
+
+use subspan::subspan;
+
+// This one emits no error.
+subspan!("");
+
+// Exactly one 'hi'.
+subspan!("hi"); //~ ERROR found 'hi's
+
+// Now two, back to back.
+subspan!("hihi"); //~ ERROR found 'hi's
+
+// Now three, back to back.
+subspan!("hihihi"); //~ ERROR found 'hi's
+
+// Now several, with spacing.
+subspan!("why I hide? hi!"); //~ ERROR found 'hi's
+subspan!("hey, hi, hidy, hidy, hi hi"); //~ ERROR found 'hi's
+subspan!("this is a hi, and this is another hi"); //~ ERROR found 'hi's
+subspan!("how are you this evening"); //~ ERROR found 'hi's
+subspan!("this is highly eradic"); //~ ERROR found 'hi's
+
+fn main() { }
--- /dev/null
+error: found 'hi's
+ --> $DIR/subspan.rs:22:1
+ |
+LL | subspan!("hi"); //~ ERROR found 'hi's
+ | ^^^^^^^^^^^^^^^
+ |
+note: here
+ --> $DIR/subspan.rs:22:11
+ |
+LL | subspan!("hi"); //~ ERROR found 'hi's
+ | ^^
+
+error: found 'hi's
+ --> $DIR/subspan.rs:25:1
+ |
+LL | subspan!("hihi"); //~ ERROR found 'hi's
+ | ^^^^^^^^^^^^^^^^^
+ |
+note: here
+ --> $DIR/subspan.rs:25:11
+ |
+LL | subspan!("hihi"); //~ ERROR found 'hi's
+ | ^^^^
+
+error: found 'hi's
+ --> $DIR/subspan.rs:28:1
+ |
+LL | subspan!("hihihi"); //~ ERROR found 'hi's
+ | ^^^^^^^^^^^^^^^^^^^
+ |
+note: here
+ --> $DIR/subspan.rs:28:11
+ |
+LL | subspan!("hihihi"); //~ ERROR found 'hi's
+ | ^^^^^^
+
+error: found 'hi's
+ --> $DIR/subspan.rs:31:1
+ |
+LL | subspan!("why I hide? hi!"); //~ ERROR found 'hi's
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+note: here
+ --> $DIR/subspan.rs:31:17
+ |
+LL | subspan!("why I hide? hi!"); //~ ERROR found 'hi's
+ | ^^ ^^
+
+error: found 'hi's
+ --> $DIR/subspan.rs:32:1
+ |
+LL | subspan!("hey, hi, hidy, hidy, hi hi"); //~ ERROR found 'hi's
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+note: here
+ --> $DIR/subspan.rs:32:16
+ |
+LL | subspan!("hey, hi, hidy, hidy, hi hi"); //~ ERROR found 'hi's
+ | ^^ ^^ ^^ ^^ ^^
+
+error: found 'hi's
+ --> $DIR/subspan.rs:33:1
+ |
+LL | subspan!("this is a hi, and this is another hi"); //~ ERROR found 'hi's
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+note: here
+ --> $DIR/subspan.rs:33:12
+ |
+LL | subspan!("this is a hi, and this is another hi"); //~ ERROR found 'hi's
+ | ^^ ^^ ^^ ^^
+
+error: found 'hi's
+ --> $DIR/subspan.rs:34:1
+ |
+LL | subspan!("how are you this evening"); //~ ERROR found 'hi's
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+note: here
+ --> $DIR/subspan.rs:34:24
+ |
+LL | subspan!("how are you this evening"); //~ ERROR found 'hi's
+ | ^^
+
+error: found 'hi's
+ --> $DIR/subspan.rs:35:1
+ |
+LL | subspan!("this is highly eradic"); //~ ERROR found 'hi's
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+note: here
+ --> $DIR/subspan.rs:35:12
+ |
+LL | subspan!("this is highly eradic"); //~ ERROR found 'hi's
+ | ^^ ^^
+
+error: aborting due to 8 previous errors
+
projects / rust.git / commitdiff