mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Keep ctxt in encoded span representation.

Browse Source
This commit is contained in:
Camille GILLOT 2022-07-03 12:20:40 +02:00
parent 75b7e52e92
commit b2a17e9bd1
2 changed files with 23 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
compiler/rustc_span/src/lib.rs
View File

@ -533,9 +533,6 @@ pub fn with_hi(self, hi: BytePos) -> Span {
self.data().with_hi(hi)
}
#[inline]
pub fn ctxt(self) -> SyntaxContext {
self.data_untracked().ctxt
}
pub fn eq_ctxt(self, other: Span) -> bool {
self.data_untracked().ctxt == other.data_untracked().ctxt
}

32
compiler/rustc_span/src/span_encoding.rs
View File

@ -28,12 +28,12 @@
/// Inline (compressed) format:
/// - `span.base_or_index == span_data.lo`
/// - `span.len_or_tag == len == span_data.hi - span_data.lo` (must be `<= MAX_LEN`)
/// - `span.ctxt == span_data.ctxt` (must be `<= MAX_CTXT`)
/// - `span.ctxt == span_data.ctxt` (must be `< MAX_CTXT`)
///
/// Interned format:
/// - `span.base_or_index == index` (indexes into the interner table)
/// - `span.len_or_tag == LEN_TAG` (high bit set, all other bits are zero)
/// - `span.ctxt == 0`
/// - `span.ctxt == span_data.ctxt` (must be < `MAX_CTXT`) or `MAX_CTXT` otherwise
///
/// The inline form uses 0 for the tag value (rather than 1) so that we don't
/// need to mask out the tag bit when getting the length, and so that the
@ -65,7 +65,7 @@
pub struct Span {
base_or_index: u32,
len_or_tag: u16,
ctxt_or_zero: u16,
ctxt_or_max: u16,
}
const LEN_TAG: u16 = 0b1000_0000_0000_0000;
@ -73,7 +73,7 @@ pub struct Span {
const MAX_CTXT: u32 = 0b1111_1111_1111_1111;
/// Dummy span, both position and length are zero, syntax context is zero as well.
pub const DUMMY_SP: Span = Span { base_or_index: 0, len_or_tag: 0, ctxt_or_zero: 0 };
pub const DUMMY_SP: Span = Span { base_or_index: 0, len_or_tag: 0, ctxt_or_max: 0 };
impl Span {
#[inline]
@ -89,14 +89,15 @@ pub fn new(
let (base, len, ctxt2) = (lo.0, hi.0 - lo.0, ctxt.as_u32());
if len <= MAX_LEN && ctxt2 <= MAX_CTXT && parent.is_none() {
if len <= MAX_LEN && ctxt2 < MAX_CTXT && parent.is_none() {
// Inline format.
Span { base_or_index: base, len_or_tag: len as u16, ctxt_or_zero: ctxt2 as u16 }
Span { base_or_index: base, len_or_tag: len as u16, ctxt_or_max: ctxt2 as u16 }
} else {
// Interned format.
let index =
with_span_interner(|interner| interner.intern(&SpanData { lo, hi, ctxt, parent }));
Span { base_or_index: index, len_or_tag: LEN_TAG, ctxt_or_zero: 0 }
let ctxt_or_max = if ctxt2 < MAX_CTXT { ctxt2 } else { MAX_CTXT } as u16;
Span { base_or_index: index, len_or_tag: LEN_TAG, ctxt_or_max }
}
}
@ -119,16 +120,29 @@ pub fn data_untracked(self) -> SpanData {
SpanData {
lo: BytePos(self.base_or_index),
hi: BytePos(self.base_or_index + self.len_or_tag as u32),
ctxt: SyntaxContext::from_u32(self.ctxt_or_zero as u32),
ctxt: SyntaxContext::from_u32(self.ctxt_or_max as u32),
parent: None,
}
} else {
// Interned format.
debug_assert!(self.ctxt_or_zero == 0);
let index = self.base_or_index;
with_span_interner(|interner| interner.spans[index as usize])
}
}
/// This function is used as a fast path when decoding the full `SpanData` is not necessary.
#[inline]
pub fn ctxt(self) -> SyntaxContext {
let ctxt_or_max = self.ctxt_or_max as u32;
if ctxt_or_max < MAX_CTXT {
// Inline format or interned format with inline ctxt.
SyntaxContext::from_u32(ctxt_or_max)
} else {
// Interned format.
let index = self.base_or_index;
with_span_interner(|interner| interner.spans[index as usize].ctxt)
}
}
}
#[derive(Default)]