rust-analyzer/crates/hir-def/src/expr_store/body.rs
2025-01-26 11:02:00 +01:00

175 lines
5.9 KiB
Rust

//! Defines `Body`: a lowered representation of functions, statics and
//! consts.
use std::ops;
use hir_expand::{InFile, Lookup};
use la_arena::{Idx, RawIdx};
use span::Edition;
use syntax::ast;
use triomphe::Arc;
use crate::{
db::DefDatabase,
expander::Expander,
expr_store::{lower, pretty, ExpressionStore, ExpressionStoreSourceMap, SelfParamPtr},
hir::{BindingId, ExprId, PatId},
item_tree::AttrOwner,
src::HasSource,
DefWithBodyId, HasModule,
};
/// The body of an item (function, const etc.).
#[derive(Debug, Eq, PartialEq)]
pub struct Body {
pub store: ExpressionStore,
/// The patterns for the function's parameters. While the parameter types are
/// part of the function signature, the patterns are not (they don't change
/// the external type of the function).
///
/// If this `Body` is for the body of a constant, this will just be
/// empty.
pub params: Box<[PatId]>,
pub self_param: Option<BindingId>,
/// The `ExprId` of the actual body expression.
pub body_expr: ExprId,
}
impl ops::Deref for Body {
type Target = ExpressionStore;
fn deref(&self) -> &Self::Target {
&self.store
}
}
/// An item body together with the mapping from syntax nodes to HIR expression
/// IDs. This is needed to go from e.g. a position in a file to the HIR
/// expression containing it; but for type inference etc., we want to operate on
/// a structure that is agnostic to the actual positions of expressions in the
/// file, so that we don't recompute types whenever some whitespace is typed.
///
/// One complication here is that, due to macro expansion, a single `Body` might
/// be spread across several files. So, for each ExprId and PatId, we record
/// both the HirFileId and the position inside the file. However, we only store
/// AST -> ExprId mapping for non-macro files, as it is not clear how to handle
/// this properly for macros.
#[derive(Default, Debug, Eq, PartialEq)]
pub struct BodySourceMap {
pub self_param: Option<InFile<SelfParamPtr>>,
pub store: ExpressionStoreSourceMap,
}
impl ops::Deref for BodySourceMap {
type Target = ExpressionStoreSourceMap;
fn deref(&self) -> &Self::Target {
&self.store
}
}
impl Body {
pub(crate) fn body_with_source_map_query(
db: &dyn DefDatabase,
def: DefWithBodyId,
) -> (Arc<Body>, Arc<BodySourceMap>) {
let _p = tracing::info_span!("body_with_source_map_query").entered();
let mut params = None;
let mut is_async_fn = false;
let InFile { file_id, value: body } = {
match def {
DefWithBodyId::FunctionId(f) => {
let data = db.function_data(f);
let f = f.lookup(db);
let src = f.source(db);
params = src.value.param_list().map(move |param_list| {
let item_tree = f.id.item_tree(db);
let func = &item_tree[f.id.value];
let krate = f.container.module(db).krate;
let crate_graph = db.crate_graph();
(
param_list,
(0..func.params.len()).map(move |idx| {
item_tree
.attrs(
db,
krate,
AttrOwner::Param(
f.id.value,
Idx::from_raw(RawIdx::from(idx as u32)),
),
)
.is_cfg_enabled(&crate_graph[krate].cfg_options)
}),
)
});
is_async_fn = data.is_async();
src.map(|it| it.body().map(ast::Expr::from))
}
DefWithBodyId::ConstId(c) => {
let c = c.lookup(db);
let src = c.source(db);
src.map(|it| it.body())
}
DefWithBodyId::StaticId(s) => {
let s = s.lookup(db);
let src = s.source(db);
src.map(|it| it.body())
}
DefWithBodyId::VariantId(v) => {
let s = v.lookup(db);
let src = s.source(db);
src.map(|it| it.expr())
}
DefWithBodyId::InTypeConstId(c) => c.lookup(db).id.map(|_| c.source(db).expr()),
}
};
let module = def.module(db);
let expander = Expander::new(db, file_id, module);
let (body, mut source_map) =
lower::lower_body(db, def, expander, params, body, module.krate, is_async_fn);
source_map.store.shrink_to_fit();
(Arc::new(body), Arc::new(source_map))
}
pub(crate) fn body_query(db: &dyn DefDatabase, def: DefWithBodyId) -> Arc<Body> {
db.body_with_source_map(def).0
}
pub fn pretty_print(
&self,
db: &dyn DefDatabase,
owner: DefWithBodyId,
edition: Edition,
) -> String {
pretty::print_body_hir(db, self, owner, edition)
}
pub fn pretty_print_expr(
&self,
db: &dyn DefDatabase,
owner: DefWithBodyId,
expr: ExprId,
edition: Edition,
) -> String {
pretty::print_expr_hir(db, self, owner, expr, edition)
}
pub fn pretty_print_pat(
&self,
db: &dyn DefDatabase,
owner: DefWithBodyId,
pat: PatId,
oneline: bool,
edition: Edition,
) -> String {
pretty::print_pat_hir(db, self, owner, pat, oneline, edition)
}
}
impl BodySourceMap {
pub fn self_param_syntax(&self) -> Option<InFile<SelfParamPtr>> {
self.self_param
}
}