Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/span/src/lib.rs')
| -rw-r--r-- | crates/span/src/lib.rs | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/crates/span/src/lib.rs b/crates/span/src/lib.rs new file mode 100644 index 0000000000..7617acde64 --- /dev/null +++ b/crates/span/src/lib.rs @@ -0,0 +1,270 @@ +//! File and span related types. +// FIXME: This should be moved into its own crate to get rid of the dependency inversion, base-db +// has business depending on tt, tt should depend on a span crate only (which unforunately will have +// to depend on salsa) +use std::fmt; + +use salsa::InternId; + +mod map; + +pub use crate::map::{RealSpanMap, SpanMap}; +pub use syntax::{TextRange, TextSize}; +pub use vfs::FileId; + +#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)] +pub struct FilePosition { + pub file_id: FileId, + pub offset: TextSize, +} + +#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)] +pub struct FileRange { + pub file_id: FileId, + pub range: TextRange, +} + +pub type ErasedFileAstId = la_arena::Idx<syntax::SyntaxNodePtr>; + +// The first inde is always the root node's AstId +pub const ROOT_ERASED_FILE_AST_ID: ErasedFileAstId = + la_arena::Idx::from_raw(la_arena::RawIdx::from_u32(0)); + +/// FileId used as the span for syntax node fixups. Any Span containing this file id is to be +/// considered fake. +pub const FIXUP_ERASED_FILE_AST_ID_MARKER: ErasedFileAstId = + // we pick the second to last for this in case we every consider making this a NonMaxU32, this + // is required to be stable for the proc-macro-server + la_arena::Idx::from_raw(la_arena::RawIdx::from_u32(!0 - 1)); + +#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)] +pub struct SpanData<Ctx> { + /// The text range of this span, relative to the anchor. + /// We need the anchor for incrementality, as storing absolute ranges will require + /// recomputation on every change in a file at all times. + pub range: TextRange, + pub anchor: SpanAnchor, + /// The syntax context of the span. + pub ctx: Ctx, +} +impl Span { + #[deprecated = "dummy spans will panic if surfaced incorrectly, as such they should be replaced appropriately"] + pub const DUMMY: Self = SpanData { + range: TextRange::empty(TextSize::new(0)), + anchor: SpanAnchor { file_id: FileId::BOGUS, ast_id: ROOT_ERASED_FILE_AST_ID }, + ctx: SyntaxContextId::ROOT, + }; +} + +pub type Span = SpanData<SyntaxContextId>; + +#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] +pub struct SyntaxContextId(InternId); + +impl fmt::Debug for SyntaxContextId { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + if *self == Self::SELF_REF { + f.debug_tuple("SyntaxContextId") + .field(&{ + #[derive(Debug)] + #[allow(non_camel_case_types)] + struct SELF_REF; + SELF_REF + }) + .finish() + } else { + f.debug_tuple("SyntaxContextId").field(&self.0).finish() + } + } +} + +impl salsa::InternKey for SyntaxContextId { + fn from_intern_id(v: salsa::InternId) -> Self { + SyntaxContextId(v) + } + fn as_intern_id(&self) -> salsa::InternId { + self.0 + } +} + +impl fmt::Display for SyntaxContextId { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "{}", self.0.as_u32()) + } +} + +// inherent trait impls please tyvm +impl SyntaxContextId { + pub const ROOT: Self = SyntaxContextId(unsafe { InternId::new_unchecked(0) }); + // veykril(HACK): FIXME salsa doesn't allow us fetching the id of the current input to be allocated so + // we need a special value that behaves as the current context. + pub const SELF_REF: Self = + SyntaxContextId(unsafe { InternId::new_unchecked(InternId::MAX - 1) }); + + pub fn is_root(self) -> bool { + self == Self::ROOT + } + + pub fn into_u32(self) -> u32 { + self.0.as_u32() + } + + pub fn from_u32(u32: u32) -> Self { + Self(InternId::from(u32)) + } +} + +#[derive(Copy, Clone, PartialEq, Eq, Hash)] +pub struct SpanAnchor { + pub file_id: FileId, + pub ast_id: ErasedFileAstId, +} + +impl fmt::Debug for SpanAnchor { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("SpanAnchor").field(&self.file_id).field(&self.ast_id.into_raw()).finish() + } +} + +/// Input to the analyzer is a set of files, where each file is identified by +/// `FileId` and contains source code. However, another source of source code in +/// Rust are macros: each macro can be thought of as producing a "temporary +/// file". To assign an id to such a file, we use the id of the macro call that +/// produced the file. So, a `HirFileId` is either a `FileId` (source code +/// written by user), or a `MacroCallId` (source code produced by macro). +/// +/// What is a `MacroCallId`? Simplifying, it's a `HirFileId` of a file +/// containing the call plus the offset of the macro call in the file. Note that +/// this is a recursive definition! However, the size_of of `HirFileId` is +/// finite (because everything bottoms out at the real `FileId`) and small +/// (`MacroCallId` uses the location interning. You can check details here: +/// <https://en.wikipedia.org/wiki/String_interning>). +/// +/// The two variants are encoded in a single u32 which are differentiated by the MSB. +/// If the MSB is 0, the value represents a `FileId`, otherwise the remaining 31 bits represent a +/// `MacroCallId`. +// FIXME: Give this a better fitting name +#[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)] +pub struct HirFileId(u32); + +impl From<HirFileId> for u32 { + fn from(value: HirFileId) -> Self { + value.0 + } +} + +impl From<MacroCallId> for HirFileId { + fn from(value: MacroCallId) -> Self { + value.as_file() + } +} + +impl fmt::Debug for HirFileId { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.repr().fmt(f) + } +} + +#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] +pub struct MacroFileId { + pub macro_call_id: MacroCallId, +} + +/// `MacroCallId` identifies a particular macro invocation, like +/// `println!("Hello, {}", world)`. +#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] +pub struct MacroCallId(salsa::InternId); + +impl salsa::InternKey for MacroCallId { + fn from_intern_id(v: salsa::InternId) -> Self { + MacroCallId(v) + } + fn as_intern_id(&self) -> salsa::InternId { + self.0 + } +} + +impl MacroCallId { + pub fn as_file(self) -> HirFileId { + MacroFileId { macro_call_id: self }.into() + } + + pub fn as_macro_file(self) -> MacroFileId { + MacroFileId { macro_call_id: self } + } +} + +#[derive(Clone, Copy, PartialEq, Eq, Hash)] +pub enum HirFileIdRepr { + FileId(FileId), + MacroFile(MacroFileId), +} + +impl fmt::Debug for HirFileIdRepr { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self { + Self::FileId(arg0) => f.debug_tuple("FileId").field(&arg0.index()).finish(), + Self::MacroFile(arg0) => { + f.debug_tuple("MacroFile").field(&arg0.macro_call_id.0).finish() + } + } + } +} + +impl From<FileId> for HirFileId { + fn from(id: FileId) -> Self { + _ = Self::ASSERT_MAX_FILE_ID_IS_SAME; + assert!(id.index() <= Self::MAX_HIR_FILE_ID, "FileId index {} is too large", id.index()); + HirFileId(id.index()) + } +} + +impl From<MacroFileId> for HirFileId { + fn from(MacroFileId { macro_call_id: MacroCallId(id) }: MacroFileId) -> Self { + _ = Self::ASSERT_MAX_FILE_ID_IS_SAME; + let id = id.as_u32(); + assert!(id <= Self::MAX_HIR_FILE_ID, "MacroCallId index {} is too large", id); + HirFileId(id | Self::MACRO_FILE_TAG_MASK) + } +} + +impl HirFileId { + const ASSERT_MAX_FILE_ID_IS_SAME: () = + [()][(Self::MAX_HIR_FILE_ID != FileId::MAX_FILE_ID) as usize]; + + const MAX_HIR_FILE_ID: u32 = u32::MAX ^ Self::MACRO_FILE_TAG_MASK; + const MACRO_FILE_TAG_MASK: u32 = 1 << 31; + + #[inline] + pub fn is_macro(self) -> bool { + self.0 & Self::MACRO_FILE_TAG_MASK != 0 + } + + #[inline] + pub fn macro_file(self) -> Option<MacroFileId> { + match self.0 & Self::MACRO_FILE_TAG_MASK { + 0 => None, + _ => Some(MacroFileId { + macro_call_id: MacroCallId(InternId::from(self.0 ^ Self::MACRO_FILE_TAG_MASK)), + }), + } + } + + #[inline] + pub fn file_id(self) -> Option<FileId> { + match self.0 & Self::MACRO_FILE_TAG_MASK { + 0 => Some(FileId::from_raw(self.0)), + _ => None, + } + } + + #[inline] + pub fn repr(self) -> HirFileIdRepr { + match self.0 & Self::MACRO_FILE_TAG_MASK { + 0 => HirFileIdRepr::FileId(FileId::from_raw(self.0)), + _ => HirFileIdRepr::MacroFile(MacroFileId { + macro_call_id: MacroCallId(InternId::from(self.0 ^ Self::MACRO_FILE_TAG_MASK)), + }), + } + } +} |