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fuchsia / third_party / rust / 972fef232ec0dd7a3f42091aa6f36cd68aeb3eef / . / src / tools / rust-analyzer / crates / hir-def / src / body / lower.rs
blob: 1ab49e91569afca7072209d403d39499242c64c7 [file] [log] [blame]
//! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
//! representation.
mod asm;
use std::mem;
use base_db::CrateId;
use either::Either;
use hir_expand::{
name::{AsName, Name},
span_map::{ExpansionSpanMap, SpanMap},
InFile, MacroDefId,
};
use intern::{sym, Symbol};
use rustc_hash::FxHashMap;
use span::AstIdMap;
use stdx::never;
use syntax::{
ast::{
self, ArrayExprKind, AstChildren, BlockExpr, HasArgList, HasAttrs, HasGenericArgs,
HasLoopBody, HasName, RangeItem, SlicePatComponents,
},
AstNode, AstPtr, AstToken as _, SyntaxNodePtr,
};
use text_size::TextSize;
use triomphe::Arc;
use crate::{
body::{Body, BodyDiagnostic, BodySourceMap, ExprPtr, HygieneId, LabelPtr, PatPtr},
builtin_type::BuiltinUint,
data::adt::StructKind,
db::DefDatabase,
expander::Expander,
hir::{
format_args::{
self, FormatAlignment, FormatArgs, FormatArgsPiece, FormatArgument, FormatArgumentKind,
FormatArgumentsCollector, FormatCount, FormatDebugHex, FormatOptions,
FormatPlaceholder, FormatSign, FormatTrait,
},
Array, Binding, BindingAnnotation, BindingId, BindingProblems, CaptureBy, ClosureKind,
Expr, ExprId, Item, Label, LabelId, Literal, LiteralOrConst, MatchArm, Movability,
OffsetOf, Pat, PatId, RecordFieldPat, RecordLitField, Statement,
},
item_scope::BuiltinShadowMode,
lang_item::LangItem,
lower::LowerCtx,
nameres::{DefMap, MacroSubNs},
path::{GenericArgs, Path},
type_ref::{Mutability, Rawness, TypeRef},
AdtId, BlockId, BlockLoc, ConstBlockLoc, DefWithBodyId, MacroId, ModuleDefId, UnresolvedMacro,
};
type FxIndexSet<K> = indexmap::IndexSet<K, std::hash::BuildHasherDefault<rustc_hash::FxHasher>>;
pub(super) fn lower(
db: &dyn DefDatabase,
owner: DefWithBodyId,
expander: Expander,
params: Option<(ast::ParamList, impl Iterator<Item = bool>)>,
body: Option<ast::Expr>,
krate: CrateId,
is_async_fn: bool,
) -> (Body, BodySourceMap) {
// We cannot leave the root span map empty and let any identifier from it be treated as root,
// because when inside nested macros `SyntaxContextId`s from the outer macro will be interleaved
// with the inner macro, and that will cause confusion because they won't be the same as `ROOT`
// even though they should be the same. Also, when the body comes from multiple expansions, their
// hygiene is different.
let span_map = expander.current_file_id().macro_file().map(|_| {
let SpanMap::ExpansionSpanMap(span_map) = expander.span_map(db) else {
panic!("in a macro file there should be `ExpansionSpanMap`");
};
Arc::clone(span_map)
});
ExprCollector {
db,
owner,
krate,
def_map: expander.module.def_map(db),
source_map: BodySourceMap::default(),
ast_id_map: db.ast_id_map(expander.current_file_id()),
body: Body::default(),
expander,
current_try_block_label: None,
is_lowering_coroutine: false,
label_ribs: Vec::new(),
current_binding_owner: None,
awaitable_context: None,
current_span_map: span_map,
current_block_legacy_macro_defs_count: FxHashMap::default(),
}
.collect(params, body, is_async_fn)
}
struct ExprCollector<'a> {
db: &'a dyn DefDatabase,
expander: Expander,
owner: DefWithBodyId,
def_map: Arc<DefMap>,
ast_id_map: Arc<AstIdMap>,
krate: CrateId,
body: Body,
source_map: BodySourceMap,
is_lowering_coroutine: bool,
/// Legacy (`macro_rules!`) macros can have multiple definitions and shadow each other,
/// and we need to find the current definition. So we track the number of definitions we saw.
current_block_legacy_macro_defs_count: FxHashMap<Name, usize>,
current_span_map: Option<Arc<ExpansionSpanMap>>,
current_try_block_label: Option<LabelId>,
// points to the expression that a try expression will target (replaces current_try_block_label)
// catch_scope: Option<ExprId>,
// points to the expression that an unlabeled control flow will target
// loop_scope: Option<ExprId>,
// needed to diagnose non label control flow in while conditions
// is_in_loop_condition: bool,
// resolution
label_ribs: Vec<LabelRib>,
current_binding_owner: Option<ExprId>,
awaitable_context: Option<Awaitable>,
}
#[derive(Clone, Debug)]
struct LabelRib {
kind: RibKind,
}
impl LabelRib {
fn new(kind: RibKind) -> Self {
LabelRib { kind }
}
}
#[derive(Clone, Debug, PartialEq, Eq)]
enum RibKind {
Normal(Name, LabelId, HygieneId),
Closure,
Constant,
MacroDef(Box<MacroDefId>),
}
impl RibKind {
/// This rib forbids referring to labels defined in upwards ribs.
fn is_label_barrier(&self) -> bool {
match self {
RibKind::Normal(..) | RibKind::MacroDef(_) => false,
RibKind::Closure | RibKind::Constant => true,
}
}
}
enum Awaitable {
Yes,
No(&'static str),
}
#[derive(Debug, Default)]
struct BindingList {
map: FxHashMap<(Name, HygieneId), BindingId>,
is_used: FxHashMap<BindingId, bool>,
reject_new: bool,
}
impl BindingList {
fn find(
&mut self,
ec: &mut ExprCollector<'_>,
name: Name,
hygiene: HygieneId,
mode: BindingAnnotation,
) -> BindingId {
let id = *self.map.entry((name, hygiene)).or_insert_with_key(|(name, _)| {
let id = ec.alloc_binding(name.clone(), mode);
if !hygiene.is_root() {
ec.body.binding_hygiene.insert(id, hygiene);
}
id
});
if ec.body.bindings[id].mode != mode {
ec.body.bindings[id].problems = Some(BindingProblems::BoundInconsistently);
}
self.check_is_used(ec, id);
id
}
fn check_is_used(&mut self, ec: &mut ExprCollector<'_>, id: BindingId) {
match self.is_used.get(&id) {
None => {
if self.reject_new {
ec.body.bindings[id].problems = Some(BindingProblems::NotBoundAcrossAll);
}
}
Some(true) => {
ec.body.bindings[id].problems = Some(BindingProblems::BoundMoreThanOnce);
}
Some(false) => {}
}
self.is_used.insert(id, true);
}
}
impl ExprCollector<'_> {
fn collect(
mut self,
param_list: Option<(ast::ParamList, impl Iterator<Item = bool>)>,
body: Option<ast::Expr>,
is_async_fn: bool,
) -> (Body, BodySourceMap) {
self.awaitable_context.replace(if is_async_fn {
Awaitable::Yes
} else {
match self.owner {
DefWithBodyId::FunctionId(..) => Awaitable::No("non-async function"),
DefWithBodyId::StaticId(..) => Awaitable::No("static"),
DefWithBodyId::ConstId(..) | DefWithBodyId::InTypeConstId(..) => {
Awaitable::No("constant")
}
DefWithBodyId::VariantId(..) => Awaitable::No("enum variant"),
}
});
if let Some((param_list, mut attr_enabled)) = param_list {
let mut params = vec![];
if let Some(self_param) =
param_list.self_param().filter(|_| attr_enabled.next().unwrap_or(false))
{
let is_mutable =
self_param.mut_token().is_some() && self_param.amp_token().is_none();
let binding_id: la_arena::Idx<Binding> = self.alloc_binding(
Name::new_symbol_root(sym::self_.clone()),
BindingAnnotation::new(is_mutable, false),
);
let hygiene = self_param
.name()
.map(|name| self.hygiene_id_for(name.syntax().text_range().start()))
.unwrap_or(HygieneId::ROOT);
if !hygiene.is_root() {
self.body.binding_hygiene.insert(binding_id, hygiene);
}
self.body.self_param = Some(binding_id);
self.source_map.self_param = Some(self.expander.in_file(AstPtr::new(&self_param)));
}
for (param, _) in param_list.params().zip(attr_enabled).filter(|(_, enabled)| *enabled)
{
let param_pat = self.collect_pat_top(param.pat());
params.push(param_pat);
}
self.body.params = params.into_boxed_slice();
};
self.body.body_expr = self.with_label_rib(RibKind::Closure, |this| {
if is_async_fn {
match body {
Some(e) => {
let syntax_ptr = AstPtr::new(&e);
let expr = this.collect_expr(e);
this.alloc_expr_desugared_with_ptr(
Expr::Async { id: None, statements: Box::new([]), tail: Some(expr) },
syntax_ptr,
)
}
None => this.missing_expr(),
}
} else {
this.collect_expr_opt(body)
}
});
(self.body, self.source_map)
}
fn ctx(&mut self) -> LowerCtx<'_> {
self.expander.ctx(self.db, &mut self.body.types, &mut self.source_map.types)
}
fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
self.maybe_collect_expr(expr).unwrap_or_else(|| self.missing_expr())
}
/// Returns `None` if and only if the expression is `#[cfg]`d out.
fn maybe_collect_expr(&mut self, expr: ast::Expr) -> Option<ExprId> {
let syntax_ptr = AstPtr::new(&expr);
self.check_cfg(&expr)?;
// FIXME: Move some of these arms out into separate methods for clarity
Some(match expr {
ast::Expr::IfExpr(e) => {
let then_branch = self.collect_block_opt(e.then_branch());
let else_branch = e.else_branch().map(|b| match b {
ast::ElseBranch::Block(it) => self.collect_block(it),
ast::ElseBranch::IfExpr(elif) => {
let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
self.collect_expr(expr)
}
});
let condition = self.collect_expr_opt(e.condition());
self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
}
ast::Expr::LetExpr(e) => {
let pat = self.collect_pat_top(e.pat());
let expr = self.collect_expr_opt(e.expr());
self.alloc_expr(Expr::Let { pat, expr }, syntax_ptr)
}
ast::Expr::BlockExpr(e) => match e.modifier() {
Some(ast::BlockModifier::Try(_)) => self.desugar_try_block(e),
Some(ast::BlockModifier::Unsafe(_)) => {
self.collect_block_(e, |id, statements, tail| Expr::Unsafe {
id,
statements,
tail,
})
}
Some(ast::BlockModifier::Label(label)) => {
let label_hygiene = self.hygiene_id_for(label.syntax().text_range().start());
let label_id = self.collect_label(label);
self.with_labeled_rib(label_id, label_hygiene, |this| {
this.collect_block_(e, |id, statements, tail| Expr::Block {
id,
statements,
tail,
label: Some(label_id),
})
})
}
Some(ast::BlockModifier::Async(_)) => {
self.with_label_rib(RibKind::Closure, |this| {
this.with_awaitable_block(Awaitable::Yes, |this| {
this.collect_block_(e, |id, statements, tail| Expr::Async {
id,
statements,
tail,
})
})
})
}
Some(ast::BlockModifier::Const(_)) => {
self.with_label_rib(RibKind::Constant, |this| {
this.with_awaitable_block(Awaitable::No("constant block"), |this| {
let (result_expr_id, prev_binding_owner) =
this.initialize_binding_owner(syntax_ptr);
let inner_expr = this.collect_block(e);
let it = this.db.intern_anonymous_const(ConstBlockLoc {
parent: this.owner,
root: inner_expr,
});
this.body.exprs[result_expr_id] = Expr::Const(it);
this.current_binding_owner = prev_binding_owner;
result_expr_id
})
})
}
// FIXME
Some(ast::BlockModifier::AsyncGen(_)) => {
self.with_awaitable_block(Awaitable::Yes, |this| this.collect_block(e))
}
Some(ast::BlockModifier::Gen(_)) => self
.with_awaitable_block(Awaitable::No("non-async gen block"), |this| {
this.collect_block(e)
}),
None => self.collect_block(e),
},
ast::Expr::LoopExpr(e) => {
let label = e.label().map(|label| {
(
self.hygiene_id_for(label.syntax().text_range().start()),
self.collect_label(label),
)
});
let body = self.collect_labelled_block_opt(label, e.loop_body());
self.alloc_expr(Expr::Loop { body, label: label.map(|it| it.1) }, syntax_ptr)
}
ast::Expr::WhileExpr(e) => self.collect_while_loop(syntax_ptr, e),
ast::Expr::ForExpr(e) => self.collect_for_loop(syntax_ptr, e),
ast::Expr::CallExpr(e) => {
let is_rustc_box = {
let attrs = e.attrs();
attrs.filter_map(|it| it.as_simple_atom()).any(|it| it == "rustc_box")
};
if is_rustc_box {
let expr = self.collect_expr_opt(e.arg_list().and_then(|it| it.args().next()));
self.alloc_expr(Expr::Box { expr }, syntax_ptr)
} else {
let callee = self.collect_expr_opt(e.expr());
let args = if let Some(arg_list) = e.arg_list() {
arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
} else {
Box::default()
};
self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
}
}
ast::Expr::MethodCallExpr(e) => {
let receiver = self.collect_expr_opt(e.receiver());
let args = if let Some(arg_list) = e.arg_list() {
arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
} else {
Box::default()
};
let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
let generic_args = e
.generic_arg_list()
.and_then(|it| GenericArgs::from_ast(&mut self.ctx(), it))
.map(Box::new);
self.alloc_expr(
Expr::MethodCall { receiver, method_name, args, generic_args },
syntax_ptr,
)
}
ast::Expr::MatchExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
let arms = if let Some(match_arm_list) = e.match_arm_list() {
match_arm_list
.arms()
.filter_map(|arm| {
self.check_cfg(&arm).map(|()| MatchArm {
pat: self.collect_pat_top(arm.pat()),
expr: self.collect_expr_opt(arm.expr()),
guard: arm
.guard()
.map(|guard| self.collect_expr_opt(guard.condition())),
})
})
.collect()
} else {
Box::default()
};
self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
}
ast::Expr::PathExpr(e) => {
let (path, hygiene) = self
.collect_expr_path(e)
.map(|(path, hygiene)| (Expr::Path(path), hygiene))
.unwrap_or((Expr::Missing, HygieneId::ROOT));
let expr_id = self.alloc_expr(path, syntax_ptr);
if !hygiene.is_root() {
self.body.expr_hygiene.insert(expr_id, hygiene);
}
expr_id
}
ast::Expr::ContinueExpr(e) => {
let label = self.resolve_label(e.lifetime()).unwrap_or_else(|e| {
self.source_map.diagnostics.push(e);
None
});
self.alloc_expr(Expr::Continue { label }, syntax_ptr)
}
ast::Expr::BreakExpr(e) => {
let label = self.resolve_label(e.lifetime()).unwrap_or_else(|e| {
self.source_map.diagnostics.push(e);
None
});
let expr = e.expr().map(|e| self.collect_expr(e));
self.alloc_expr(Expr::Break { expr, label }, syntax_ptr)
}
ast::Expr::ParenExpr(e) => {
let inner = self.collect_expr_opt(e.expr());
// make the paren expr point to the inner expression as well for IDE resolution
let src = self.expander.in_file(syntax_ptr);
self.source_map.expr_map.insert(src, inner.into());
inner
}
ast::Expr::ReturnExpr(e) => {
let expr = e.expr().map(|e| self.collect_expr(e));
self.alloc_expr(Expr::Return { expr }, syntax_ptr)
}
ast::Expr::BecomeExpr(e) => {
let expr =
e.expr().map(|e| self.collect_expr(e)).unwrap_or_else(|| self.missing_expr());
self.alloc_expr(Expr::Become { expr }, syntax_ptr)
}
ast::Expr::YieldExpr(e) => {
self.is_lowering_coroutine = true;
let expr = e.expr().map(|e| self.collect_expr(e));
self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
}
ast::Expr::YeetExpr(e) => {
let expr = e.expr().map(|e| self.collect_expr(e));
self.alloc_expr(Expr::Yeet { expr }, syntax_ptr)
}
ast::Expr::RecordExpr(e) => {
let path = e.path().and_then(|path| self.parse_path(path)).map(Box::new);
let record_lit = if let Some(nfl) = e.record_expr_field_list() {
let fields = nfl
.fields()
.filter_map(|field| {
self.check_cfg(&field)?;
let name = field.field_name()?.as_name();
let expr = match field.expr() {
Some(e) => self.collect_expr(e),
None => self.missing_expr(),
};
let src = self.expander.in_file(AstPtr::new(&field));
self.source_map.field_map_back.insert(expr, src);
Some(RecordLitField { name, expr })
})
.collect();
let spread = nfl.spread().map(|s| self.collect_expr(s));
Expr::RecordLit { path, fields, spread }
} else {
Expr::RecordLit { path, fields: Box::default(), spread: None }
};
self.alloc_expr(record_lit, syntax_ptr)
}
ast::Expr::FieldExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
let name = match e.field_access() {
Some(kind) => kind.as_name(),
_ => Name::missing(),
};
self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
}
ast::Expr::AwaitExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
if let Awaitable::No(location) = self.is_lowering_awaitable_block() {
self.source_map.diagnostics.push(BodyDiagnostic::AwaitOutsideOfAsync {
node: InFile::new(self.expander.current_file_id(), AstPtr::new(&e)),
location: location.to_string(),
});
}
self.alloc_expr(Expr::Await { expr }, syntax_ptr)
}
ast::Expr::TryExpr(e) => self.collect_try_operator(syntax_ptr, e),
ast::Expr::CastExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
let type_ref = TypeRef::from_ast_opt(&mut self.ctx(), e.ty());
self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
}
ast::Expr::RefExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
let raw_tok = e.raw_token().is_some();
let mutability = if raw_tok {
if e.mut_token().is_some() {
Mutability::Mut
} else if e.const_token().is_some() {
Mutability::Shared
} else {
never!("parser only remaps to raw_token() if matching mutability token follows");
Mutability::Shared
}
} else {
Mutability::from_mutable(e.mut_token().is_some())
};
let rawness = Rawness::from_raw(raw_tok);
self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
}
ast::Expr::PrefixExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
match e.op_kind() {
Some(op) => self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr),
None => self.alloc_expr(Expr::Missing, syntax_ptr),
}
}
ast::Expr::ClosureExpr(e) => self.with_label_rib(RibKind::Closure, |this| {
let (result_expr_id, prev_binding_owner) =
this.initialize_binding_owner(syntax_ptr);
let mut args = Vec::new();
let mut arg_types = Vec::new();
if let Some(pl) = e.param_list() {
let num_params = pl.params().count();
args.reserve_exact(num_params);
arg_types.reserve_exact(num_params);
for param in pl.params() {
let pat = this.collect_pat_top(param.pat());
let type_ref = param.ty().map(|it| TypeRef::from_ast(&mut this.ctx(), it));
args.push(pat);
arg_types.push(type_ref);
}
}
let ret_type = e
.ret_type()
.and_then(|r| r.ty())
.map(|it| TypeRef::from_ast(&mut this.ctx(), it));
let prev_is_lowering_coroutine = mem::take(&mut this.is_lowering_coroutine);
let prev_try_block_label = this.current_try_block_label.take();
let awaitable = if e.async_token().is_some() {
Awaitable::Yes
} else {
Awaitable::No("non-async closure")
};
let body =
this.with_awaitable_block(awaitable, |this| this.collect_expr_opt(e.body()));
let closure_kind = if this.is_lowering_coroutine {
let movability = if e.static_token().is_some() {
Movability::Static
} else {
Movability::Movable
};
ClosureKind::Coroutine(movability)
} else if e.async_token().is_some() {
ClosureKind::Async
} else {
ClosureKind::Closure
};
let capture_by =
if e.move_token().is_some() { CaptureBy::Value } else { CaptureBy::Ref };
this.is_lowering_coroutine = prev_is_lowering_coroutine;
this.current_binding_owner = prev_binding_owner;
this.current_try_block_label = prev_try_block_label;
this.body.exprs[result_expr_id] = Expr::Closure {
args: args.into(),
arg_types: arg_types.into(),
ret_type,
body,
closure_kind,
capture_by,
};
result_expr_id
}),
ast::Expr::BinExpr(e) => {
let op = e.op_kind();
if let Some(ast::BinaryOp::Assignment { op: None }) = op {
let target = self.collect_expr_as_pat_opt(e.lhs());
let value = self.collect_expr_opt(e.rhs());
self.alloc_expr(Expr::Assignment { target, value }, syntax_ptr)
} else {
let lhs = self.collect_expr_opt(e.lhs());
let rhs = self.collect_expr_opt(e.rhs());
self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
}
}
ast::Expr::TupleExpr(e) => {
let mut exprs: Vec<_> = e.fields().map(|expr| self.collect_expr(expr)).collect();
// if there is a leading comma, the user is most likely to type out a leading expression
// so we insert a missing expression at the beginning for IDE features
if comma_follows_token(e.l_paren_token()) {
exprs.insert(0, self.missing_expr());
}
self.alloc_expr(Expr::Tuple { exprs: exprs.into_boxed_slice() }, syntax_ptr)
}
ast::Expr::ArrayExpr(e) => {
let kind = e.kind();
match kind {
ArrayExprKind::ElementList(e) => {
let elements = e.map(|expr| self.collect_expr(expr)).collect();
self.alloc_expr(Expr::Array(Array::ElementList { elements }), syntax_ptr)
}
ArrayExprKind::Repeat { initializer, repeat } => {
let initializer = self.collect_expr_opt(initializer);
let repeat = self.with_label_rib(RibKind::Constant, |this| {
if let Some(repeat) = repeat {
let syntax_ptr = AstPtr::new(&repeat);
this.collect_as_a_binding_owner_bad(
|this| this.collect_expr(repeat),
syntax_ptr,
)
} else {
this.missing_expr()
}
});
self.alloc_expr(
Expr::Array(Array::Repeat { initializer, repeat }),
syntax_ptr,
)
}
}
}
ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
ast::Expr::IndexExpr(e) => {
let base = self.collect_expr_opt(e.base());
let index = self.collect_expr_opt(e.index());
self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
}
ast::Expr::RangeExpr(e) => {
let lhs = e.start().map(|lhs| self.collect_expr(lhs));
let rhs = e.end().map(|rhs| self.collect_expr(rhs));
match e.op_kind() {
Some(range_type) => {
self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
}
None => self.alloc_expr(Expr::Missing, syntax_ptr),
}
}
ast::Expr::MacroExpr(e) => {
let e = e.macro_call()?;
let macro_ptr = AstPtr::new(&e);
let id = self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
expansion.map(|it| this.collect_expr(it))
});
match id {
Some(id) => {
// Make the macro-call point to its expanded expression so we can query
// semantics on syntax pointers to the macro
let src = self.expander.in_file(syntax_ptr);
self.source_map.expr_map.insert(src, id.into());
id
}
None => self.alloc_expr(Expr::Missing, syntax_ptr),
}
}
ast::Expr::UnderscoreExpr(_) => self.alloc_expr(Expr::Underscore, syntax_ptr),
ast::Expr::AsmExpr(e) => self.lower_inline_asm(e, syntax_ptr),
ast::Expr::OffsetOfExpr(e) => {
let container = TypeRef::from_ast_opt(&mut self.ctx(), e.ty());
let fields = e.fields().map(|it| it.as_name()).collect();
self.alloc_expr(Expr::OffsetOf(OffsetOf { container, fields }), syntax_ptr)
}
ast::Expr::FormatArgsExpr(f) => self.collect_format_args(f, syntax_ptr),
})
}
fn parse_path(&mut self, path: ast::Path) -> Option<Path> {
self.expander.parse_path(self.db, path, &mut self.body.types, &mut self.source_map.types)
}
fn collect_expr_path(&mut self, e: ast::PathExpr) -> Option<(Path, HygieneId)> {
e.path().and_then(|path| {
let path = self.parse_path(path)?;
// Need to enable `mod_path.len() < 1` for `self`.
let may_be_variable = matches!(&path, Path::BarePath(mod_path) if mod_path.len() <= 1);
let hygiene = if may_be_variable {
self.hygiene_id_for(e.syntax().text_range().start())
} else {
HygieneId::ROOT
};
Some((path, hygiene))
})
}
fn collect_expr_as_pat_opt(&mut self, expr: Option<ast::Expr>) -> PatId {
match expr {
Some(expr) => self.collect_expr_as_pat(expr),
_ => self.missing_pat(),
}
}
fn collect_expr_as_pat(&mut self, expr: ast::Expr) -> PatId {
self.maybe_collect_expr_as_pat(&expr).unwrap_or_else(|| {
let src = self.expander.in_file(AstPtr::new(&expr).wrap_left());
let expr = self.collect_expr(expr);
// Do not use `alloc_pat_from_expr()` here, it will override the entry in `expr_map`.
let id = self.body.pats.alloc(Pat::Expr(expr));
self.source_map.pat_map_back.insert(id, src);
id
})
}
fn maybe_collect_expr_as_pat(&mut self, expr: &ast::Expr) -> Option<PatId> {
self.check_cfg(expr)?;
let syntax_ptr = AstPtr::new(expr);
let result = match expr {
ast::Expr::UnderscoreExpr(_) => self.alloc_pat_from_expr(Pat::Wild, syntax_ptr),
ast::Expr::ParenExpr(e) => {
// We special-case `(..)` for consistency with patterns.
if let Some(ast::Expr::RangeExpr(range)) = e.expr() {
if range.is_range_full() {
return Some(self.alloc_pat_from_expr(
Pat::Tuple { args: Box::default(), ellipsis: Some(0) },
syntax_ptr,
));
}
}
return e.expr().and_then(|expr| self.maybe_collect_expr_as_pat(&expr));
}
ast::Expr::TupleExpr(e) => {
let (ellipsis, args) = collect_tuple(self, e.fields());
self.alloc_pat_from_expr(Pat::Tuple { args, ellipsis }, syntax_ptr)
}
ast::Expr::ArrayExpr(e) => {
if e.semicolon_token().is_some() {
return None;
}
let mut elements = e.exprs();
let prefix = elements
.by_ref()
.map_while(|elem| collect_possibly_rest(self, elem).left())
.collect();
let suffix = elements.map(|elem| self.collect_expr_as_pat(elem)).collect();
self.alloc_pat_from_expr(Pat::Slice { prefix, slice: None, suffix }, syntax_ptr)
}
ast::Expr::CallExpr(e) => {
let path = collect_path(self, e.expr()?)?;
let path = path.path().and_then(|path| self.parse_path(path)).map(Box::new);
let (ellipsis, args) = collect_tuple(self, e.arg_list()?.args());
self.alloc_pat_from_expr(Pat::TupleStruct { path, args, ellipsis }, syntax_ptr)
}
ast::Expr::PathExpr(e) => {
let (path, hygiene) = self
.collect_expr_path(e.clone())
.map(|(path, hygiene)| (Pat::Path(path), hygiene))
.unwrap_or((Pat::Missing, HygieneId::ROOT));
let pat_id = self.alloc_pat_from_expr(path, syntax_ptr);
if !hygiene.is_root() {
self.body.pat_hygiene.insert(pat_id, hygiene);
}
pat_id
}
ast::Expr::MacroExpr(e) => {
let e = e.macro_call()?;
let macro_ptr = AstPtr::new(&e);
let src = self.expander.in_file(AstPtr::new(expr));
let id = self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
this.collect_expr_as_pat_opt(expansion)
});
self.source_map.expr_map.insert(src, id.into());
id
}
ast::Expr::RecordExpr(e) => {
let path = e.path().and_then(|path| self.parse_path(path)).map(Box::new);
let record_field_list = e.record_expr_field_list()?;
let ellipsis = record_field_list.dotdot_token().is_some();
// FIXME: Report an error here if `record_field_list.spread().is_some()`.
let args = record_field_list
.fields()
.filter_map(|f| {
self.check_cfg(&f)?;
let field_expr = f.expr()?;
let pat = self.collect_expr_as_pat(field_expr);
let name = f.field_name()?.as_name();
let src = self.expander.in_file(AstPtr::new(&f).wrap_left());
self.source_map.pat_field_map_back.insert(pat, src);
Some(RecordFieldPat { name, pat })
})
.collect();
self.alloc_pat_from_expr(Pat::Record { path, args, ellipsis }, syntax_ptr)
}
_ => return None,
};
return Some(result);
fn collect_path(this: &mut ExprCollector<'_>, expr: ast::Expr) -> Option<ast::PathExpr> {
match expr {
ast::Expr::PathExpr(e) => Some(e),
ast::Expr::MacroExpr(mac) => {
let call = mac.macro_call()?;
{
let macro_ptr = AstPtr::new(&call);
this.collect_macro_call(call, macro_ptr, true, |this, expanded_path| {
collect_path(this, expanded_path?)
})
}
}
_ => None,
}
}
fn collect_possibly_rest(
this: &mut ExprCollector<'_>,
expr: ast::Expr,
) -> Either<PatId, ()> {
match &expr {
ast::Expr::RangeExpr(e) if e.is_range_full() => Either::Right(()),
ast::Expr::MacroExpr(mac) => match mac.macro_call() {
Some(call) => {
let macro_ptr = AstPtr::new(&call);
let pat = this.collect_macro_call(
call,
macro_ptr,
true,
|this, expanded_expr| match expanded_expr {
Some(expanded_pat) => collect_possibly_rest(this, expanded_pat),
None => Either::Left(this.missing_pat()),
},
);
if let Either::Left(pat) = pat {
let src = this.expander.in_file(AstPtr::new(&expr).wrap_left());
this.source_map.pat_map_back.insert(pat, src);
}
pat
}
None => {
let ptr = AstPtr::new(&expr);
Either::Left(this.alloc_pat_from_expr(Pat::Missing, ptr))
}
},
_ => Either::Left(this.collect_expr_as_pat(expr)),
}
}
fn collect_tuple(
this: &mut ExprCollector<'_>,
fields: ast::AstChildren<ast::Expr>,
) -> (Option<u32>, Box<[la_arena::Idx<Pat>]>) {
let mut ellipsis = None;
let args = fields
.enumerate()
.filter_map(|(idx, elem)| {
match collect_possibly_rest(this, elem) {
Either::Left(pat) => Some(pat),
Either::Right(()) => {
if ellipsis.is_none() {
ellipsis = Some(idx as u32);
}
// FIXME: Report an error here otherwise.
None
}
}
})
.collect();
(ellipsis, args)
}
}
fn initialize_binding_owner(
&mut self,
syntax_ptr: AstPtr<ast::Expr>,
) -> (ExprId, Option<ExprId>) {
let result_expr_id = self.alloc_expr(Expr::Missing, syntax_ptr);
let prev_binding_owner = self.current_binding_owner.take();
self.current_binding_owner = Some(result_expr_id);
(result_expr_id, prev_binding_owner)
}
/// FIXME: This function is bad. It will produce a dangling `Missing` expr which wastes memory. Currently
/// it is used only for const blocks and repeat expressions, which are also hacky and ideally should have
/// their own body. Don't add more usage for this function so that we can remove this function after
/// separating those bodies.
fn collect_as_a_binding_owner_bad(
&mut self,
job: impl FnOnce(&mut ExprCollector<'_>) -> ExprId,
syntax_ptr: AstPtr<ast::Expr>,
) -> ExprId {
let (id, prev_owner) = self.initialize_binding_owner(syntax_ptr);
let tmp = job(self);
self.body.exprs[id] = mem::replace(&mut self.body.exprs[tmp], Expr::Missing);
self.current_binding_owner = prev_owner;
id
}
/// Desugar `try { <stmts>; <expr> }` into `'<new_label>: { <stmts>; ::std::ops::Try::from_output(<expr>) }`,
/// `try { <stmts>; }` into `'<new_label>: { <stmts>; ::std::ops::Try::from_output(()) }`
/// and save the `<new_label>` to use it as a break target for desugaring of the `?` operator.
fn desugar_try_block(&mut self, e: BlockExpr) -> ExprId {
let Some(try_from_output) = self.lang_path(LangItem::TryTraitFromOutput) else {
return self.collect_block(e);
};
let label = self
.alloc_label_desugared(Label { name: Name::generate_new_name(self.body.labels.len()) });
let old_label = self.current_try_block_label.replace(label);
let ptr = AstPtr::new(&e).upcast();
let (btail, expr_id) = self.with_labeled_rib(label, HygieneId::ROOT, |this| {
let mut btail = None;
let block = this.collect_block_(e, |id, statements, tail| {
btail = tail;
Expr::Block { id, statements, tail, label: Some(label) }
});
(btail, block)
});
let callee = self.alloc_expr_desugared_with_ptr(Expr::Path(try_from_output), ptr);
let next_tail = match btail {
Some(tail) => self
.alloc_expr_desugared_with_ptr(Expr::Call { callee, args: Box::new([tail]) }, ptr),
None => {
let unit =
self.alloc_expr_desugared_with_ptr(Expr::Tuple { exprs: Box::new([]) }, ptr);
self.alloc_expr_desugared_with_ptr(
Expr::Call { callee, args: Box::new([unit]) },
ptr,
)
}
};
let Expr::Block { tail, .. } = &mut self.body.exprs[expr_id] else {
unreachable!("block was lowered to non-block");
};
*tail = Some(next_tail);
self.current_try_block_label = old_label;
expr_id
}
/// Desugar `ast::WhileExpr` from: `[opt_ident]: while <cond> <body>` into:
/// ```ignore (pseudo-rust)
/// [opt_ident]: loop {
/// if <cond> {
/// <body>
/// }
/// else {
/// break;
/// }
/// }
/// ```
/// FIXME: Rustc wraps the condition in a construct equivalent to `{ let _t = <cond>; _t }`
/// to preserve drop semantics. We should probably do the same in future.
fn collect_while_loop(&mut self, syntax_ptr: AstPtr<ast::Expr>, e: ast::WhileExpr) -> ExprId {
let label = e.label().map(|label| {
(self.hygiene_id_for(label.syntax().text_range().start()), self.collect_label(label))
});
let body = self.collect_labelled_block_opt(label, e.loop_body());
// Labels can also be used in the condition expression, like this:
// ```
// fn main() {
// let mut optional = Some(0);
// 'my_label: while let Some(a) = match optional {
// None => break 'my_label,
// Some(val) => Some(val),
// } {
// println!("{}", a);
// optional = None;
// }
// }
// ```
let condition = match label {
Some((label_hygiene, label)) => self.with_labeled_rib(label, label_hygiene, |this| {
this.collect_expr_opt(e.condition())
}),
None => self.collect_expr_opt(e.condition()),
};
let break_expr = self.alloc_expr(Expr::Break { expr: None, label: None }, syntax_ptr);
let if_expr = self.alloc_expr(
Expr::If { condition, then_branch: body, else_branch: Some(break_expr) },
syntax_ptr,
);
self.alloc_expr(Expr::Loop { body: if_expr, label: label.map(|it| it.1) }, syntax_ptr)
}
/// Desugar `ast::ForExpr` from: `[opt_ident]: for <pat> in <head> <body>` into:
/// ```ignore (pseudo-rust)
/// match IntoIterator::into_iter(<head>) {
/// mut iter => {
/// [opt_ident]: loop {
/// match Iterator::next(&mut iter) {
/// None => break,
/// Some(<pat>) => <body>,
/// };
/// }
/// }
/// }
/// ```
fn collect_for_loop(&mut self, syntax_ptr: AstPtr<ast::Expr>, e: ast::ForExpr) -> ExprId {
let Some((into_iter_fn, iter_next_fn, option_some, option_none)) = (|| {
Some((
self.lang_path(LangItem::IntoIterIntoIter)?,
self.lang_path(LangItem::IteratorNext)?,
self.lang_path(LangItem::OptionSome)?,
self.lang_path(LangItem::OptionNone)?,
))
})() else {
// Some of the needed lang items are missing, so we can't desugar
return self.alloc_expr(Expr::Missing, syntax_ptr);
};
let head = self.collect_expr_opt(e.iterable());
let into_iter_fn_expr = self.alloc_expr(Expr::Path(into_iter_fn), syntax_ptr);
let iterator = self.alloc_expr(
Expr::Call { callee: into_iter_fn_expr, args: Box::new([head]) },
syntax_ptr,
);
let none_arm = MatchArm {
pat: self.alloc_pat_desugared(Pat::Path(option_none)),
guard: None,
expr: self.alloc_expr(Expr::Break { expr: None, label: None }, syntax_ptr),
};
let some_pat = Pat::TupleStruct {
path: Some(Box::new(option_some)),
args: Box::new([self.collect_pat_top(e.pat())]),
ellipsis: None,
};
let label = e.label().map(|label| {
(self.hygiene_id_for(label.syntax().text_range().start()), self.collect_label(label))
});
let some_arm = MatchArm {
pat: self.alloc_pat_desugared(some_pat),
guard: None,
expr: self.with_opt_labeled_rib(label, |this| {
this.collect_expr_opt(e.loop_body().map(|it| it.into()))
}),
};
let iter_name = Name::generate_new_name(self.body.exprs.len());
let iter_expr = self.alloc_expr(Expr::Path(Path::from(iter_name.clone())), syntax_ptr);
let iter_expr_mut = self.alloc_expr(
Expr::Ref { expr: iter_expr, rawness: Rawness::Ref, mutability: Mutability::Mut },
syntax_ptr,
);
let iter_next_fn_expr = self.alloc_expr(Expr::Path(iter_next_fn), syntax_ptr);
let iter_next_expr = self.alloc_expr(
Expr::Call { callee: iter_next_fn_expr, args: Box::new([iter_expr_mut]) },
syntax_ptr,
);
let loop_inner = self.alloc_expr(
Expr::Match { expr: iter_next_expr, arms: Box::new([none_arm, some_arm]) },
syntax_ptr,
);
let loop_inner = self.alloc_expr(
Expr::Block {
id: None,
statements: Box::default(),
tail: Some(loop_inner),
label: None,
},
syntax_ptr,
);
let loop_outer = self
.alloc_expr(Expr::Loop { body: loop_inner, label: label.map(|it| it.1) }, syntax_ptr);
let iter_binding = self.alloc_binding(iter_name, BindingAnnotation::Mutable);
let iter_pat = self.alloc_pat_desugared(Pat::Bind { id: iter_binding, subpat: None });
self.add_definition_to_binding(iter_binding, iter_pat);
self.alloc_expr(
Expr::Match {
expr: iterator,
arms: Box::new([MatchArm { pat: iter_pat, guard: None, expr: loop_outer }]),
},
syntax_ptr,
)
}
/// Desugar `ast::TryExpr` from: `<expr>?` into:
/// ```ignore (pseudo-rust)
/// match Try::branch(<expr>) {
/// ControlFlow::Continue(val) => val,
/// ControlFlow::Break(residual) =>
/// // If there is an enclosing `try {...}`:
/// break 'catch_target Try::from_residual(residual),
/// // Otherwise:
/// return Try::from_residual(residual),
/// }
/// ```
fn collect_try_operator(&mut self, syntax_ptr: AstPtr<ast::Expr>, e: ast::TryExpr) -> ExprId {
let Some((try_branch, cf_continue, cf_break, try_from_residual)) = (|| {
Some((
self.lang_path(LangItem::TryTraitBranch)?,
self.lang_path(LangItem::ControlFlowContinue)?,
self.lang_path(LangItem::ControlFlowBreak)?,
self.lang_path(LangItem::TryTraitFromResidual)?,
))
})() else {
// Some of the needed lang items are missing, so we can't desugar
return self.alloc_expr(Expr::Missing, syntax_ptr);
};
let operand = self.collect_expr_opt(e.expr());
let try_branch = self.alloc_expr(Expr::Path(try_branch), syntax_ptr);
let expr = self
.alloc_expr(Expr::Call { callee: try_branch, args: Box::new([operand]) }, syntax_ptr);
let continue_name = Name::generate_new_name(self.body.bindings.len());
let continue_binding =
self.alloc_binding(continue_name.clone(), BindingAnnotation::Unannotated);
let continue_bpat =
self.alloc_pat_desugared(Pat::Bind { id: continue_binding, subpat: None });
self.add_definition_to_binding(continue_binding, continue_bpat);
let continue_arm = MatchArm {
pat: self.alloc_pat_desugared(Pat::TupleStruct {
path: Some(Box::new(cf_continue)),
args: Box::new([continue_bpat]),
ellipsis: None,
}),
guard: None,
expr: self.alloc_expr(Expr::Path(Path::from(continue_name)), syntax_ptr),
};
let break_name = Name::generate_new_name(self.body.bindings.len());
let break_binding = self.alloc_binding(break_name.clone(), BindingAnnotation::Unannotated);
let break_bpat = self.alloc_pat_desugared(Pat::Bind { id: break_binding, subpat: None });
self.add_definition_to_binding(break_binding, break_bpat);
let break_arm = MatchArm {
pat: self.alloc_pat_desugared(Pat::TupleStruct {
path: Some(Box::new(cf_break)),
args: Box::new([break_bpat]),
ellipsis: None,
}),
guard: None,
expr: {
let it = self.alloc_expr(Expr::Path(Path::from(break_name)), syntax_ptr);
let callee = self.alloc_expr(Expr::Path(try_from_residual), syntax_ptr);
let result =
self.alloc_expr(Expr::Call { callee, args: Box::new([it]) }, syntax_ptr);
self.alloc_expr(
match self.current_try_block_label {
Some(label) => Expr::Break { expr: Some(result), label: Some(label) },
None => Expr::Return { expr: Some(result) },
},
syntax_ptr,
)
},
};
let arms = Box::new([continue_arm, break_arm]);
self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
}
fn collect_macro_call<T, U>(
&mut self,
mcall: ast::MacroCall,
syntax_ptr: AstPtr<ast::MacroCall>,
record_diagnostics: bool,
collector: impl FnOnce(&mut Self, Option<T>) -> U,
) -> U
where
T: ast::AstNode,
{
// File containing the macro call. Expansion errors will be attached here.
let outer_file = self.expander.current_file_id();
let macro_call_ptr = self.expander.in_file(syntax_ptr);
let module = self.expander.module.local_id;
let res = match self.def_map.modules[module]
.scope
.macro_invoc(InFile::new(outer_file, self.ast_id_map.ast_id_for_ptr(syntax_ptr)))
{
// fast path, macro call is in a block module
Some(call) => Ok(self.expander.enter_expand_id(self.db, call)),
None => self.expander.enter_expand(self.db, mcall, |path| {
self.def_map
.resolve_path(
self.db,
module,
path,
crate::item_scope::BuiltinShadowMode::Other,
Some(MacroSubNs::Bang),
)
.0
.take_macros()
}),
};
let res = match res {
Ok(res) => res,
Err(UnresolvedMacro { path }) => {
if record_diagnostics {
self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall {
node: InFile::new(outer_file, syntax_ptr),
path,
});
}
return collector(self, None);
}
};
if record_diagnostics {
if let Some(err) = res.err {
self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
node: InFile::new(outer_file, syntax_ptr),
err,
});
}
}
match res.value {
Some((mark, expansion)) => {
// Keep collecting even with expansion errors so we can provide completions and
// other services in incomplete macro expressions.
if let Some(macro_file) = self.expander.current_file_id().macro_file() {
self.source_map.expansions.insert(macro_call_ptr, macro_file);
}
let prev_ast_id_map = mem::replace(
&mut self.ast_id_map,
self.db.ast_id_map(self.expander.current_file_id()),
);
if record_diagnostics {
// FIXME: Report parse errors here
}
let SpanMap::ExpansionSpanMap(new_span_map) = self.expander.span_map(self.db)
else {
panic!("just expanded a macro, ExpansionSpanMap should be available");
};
let old_span_map =
mem::replace(&mut self.current_span_map, Some(new_span_map.clone()));
let id = collector(self, Some(expansion.tree()));
self.current_span_map = old_span_map;
self.ast_id_map = prev_ast_id_map;
self.expander.exit(mark);
id
}
None => collector(self, None),
}
}
fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
match expr {
Some(expr) => self.collect_expr(expr),
None => self.missing_expr(),
}
}
fn collect_macro_as_stmt(
&mut self,
statements: &mut Vec<Statement>,
mac: ast::MacroExpr,
) -> Option<ExprId> {
let mac_call = mac.macro_call()?;
let syntax_ptr = AstPtr::new(&ast::Expr::from(mac));
let macro_ptr = AstPtr::new(&mac_call);
let expansion = self.collect_macro_call(
mac_call,
macro_ptr,
false,
|this, expansion: Option<ast::MacroStmts>| match expansion {
Some(expansion) => {
expansion.statements().for_each(|stmt| this.collect_stmt(statements, stmt));
expansion.expr().and_then(|expr| match expr {
ast::Expr::MacroExpr(mac) => this.collect_macro_as_stmt(statements, mac),
expr => Some(this.collect_expr(expr)),
})
}
None => None,
},
);
expansion.inspect(|&tail| {
// Make the macro-call point to its expanded expression so we can query
// semantics on syntax pointers to the macro
let src = self.expander.in_file(syntax_ptr);
self.source_map.expr_map.insert(src, tail.into());
})
}
fn collect_stmt(&mut self, statements: &mut Vec<Statement>, s: ast::Stmt) {
match s {
ast::Stmt::LetStmt(stmt) => {
if self.check_cfg(&stmt).is_none() {
return;
}
let pat = self.collect_pat_top(stmt.pat());
let type_ref = stmt.ty().map(|it| TypeRef::from_ast(&mut self.ctx(), it));
let initializer = stmt.initializer().map(|e| self.collect_expr(e));
let else_branch = stmt
.let_else()
.and_then(|let_else| let_else.block_expr())
.map(|block| self.collect_block(block));
statements.push(Statement::Let { pat, type_ref, initializer, else_branch });
}
ast::Stmt::ExprStmt(stmt) => {
let expr = stmt.expr();
match &expr {
Some(expr) if self.check_cfg(expr).is_none() => return,
_ => (),
}
let has_semi = stmt.semicolon_token().is_some();
// Note that macro could be expanded to multiple statements
if let Some(ast::Expr::MacroExpr(mac)) = expr {
if let Some(expr) = self.collect_macro_as_stmt(statements, mac) {
statements.push(Statement::Expr { expr, has_semi })
}
} else {
let expr = self.collect_expr_opt(expr);
statements.push(Statement::Expr { expr, has_semi });
}
}
ast::Stmt::Item(ast::Item::MacroDef(macro_)) => {
let Some(name) = macro_.name() else {
statements.push(Statement::Item(Item::Other));
return;
};
let name = name.as_name();
let macro_id = self.def_map.modules[DefMap::ROOT].scope.get(&name).take_macros();
self.collect_macro_def(statements, macro_id);
}
ast::Stmt::Item(ast::Item::MacroRules(macro_)) => {
let Some(name) = macro_.name() else {
statements.push(Statement::Item(Item::Other));
return;
};
let name = name.as_name();
let macro_defs_count =
self.current_block_legacy_macro_defs_count.entry(name.clone()).or_insert(0);
let macro_id = self.def_map.modules[DefMap::ROOT]
.scope
.get_legacy_macro(&name)
.and_then(|it| it.get(*macro_defs_count))
.copied();
*macro_defs_count += 1;
self.collect_macro_def(statements, macro_id);
}
ast::Stmt::Item(_item) => statements.push(Statement::Item(Item::Other)),
}
}
fn collect_macro_def(&mut self, statements: &mut Vec<Statement>, macro_id: Option<MacroId>) {
let Some(macro_id) = macro_id else {
never!("def map should have macro definition, but it doesn't");
statements.push(Statement::Item(Item::Other));
return;
};
let macro_id = self.db.macro_def(macro_id);
statements.push(Statement::Item(Item::MacroDef(Box::new(macro_id))));
self.label_ribs.push(LabelRib::new(RibKind::MacroDef(Box::new(macro_id))));
}
fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
self.collect_block_(block, |id, statements, tail| Expr::Block {
id,
statements,
tail,
label: None,
})
}
fn collect_block_(
&mut self,
block: ast::BlockExpr,
mk_block: impl FnOnce(Option<BlockId>, Box<[Statement]>, Option<ExprId>) -> Expr,
) -> ExprId {
let block_has_items = {
let statement_has_item = block.statements().any(|stmt| match stmt {
ast::Stmt::Item(_) => true,
// Macro calls can be both items and expressions. The syntax library always treats
// them as expressions here, so we undo that.
ast::Stmt::ExprStmt(es) => matches!(es.expr(), Some(ast::Expr::MacroExpr(_))),
_ => false,
});
statement_has_item
|| matches!(block.tail_expr(), Some(ast::Expr::MacroExpr(_)))
|| (block.may_carry_attributes() && block.attrs().next().is_some())
};
let block_id = if block_has_items {
let file_local_id = self.ast_id_map.ast_id(&block);
let ast_id = self.expander.in_file(file_local_id);
Some(self.db.intern_block(BlockLoc { ast_id, module: self.expander.module }))
} else {
None
};
let (module, def_map) =
match block_id.map(|block_id| (self.db.block_def_map(block_id), block_id)) {
Some((def_map, block_id)) => {
self.body.block_scopes.push(block_id);
(def_map.module_id(DefMap::ROOT), def_map)
}
None => (self.expander.module, self.def_map.clone()),
};
let prev_def_map = mem::replace(&mut self.def_map, def_map);
let prev_local_module = mem::replace(&mut self.expander.module, module);
let prev_legacy_macros_count = mem::take(&mut self.current_block_legacy_macro_defs_count);
let mut statements = Vec::new();
block.statements().for_each(|s| self.collect_stmt(&mut statements, s));
let tail = block.tail_expr().and_then(|e| match e {
ast::Expr::MacroExpr(mac) => self.collect_macro_as_stmt(&mut statements, mac),
expr => self.maybe_collect_expr(expr),
});
let tail = tail.or_else(|| {
let stmt = statements.pop()?;
if let Statement::Expr { expr, has_semi: false } = stmt {
return Some(expr);
}
statements.push(stmt);
None
});
let syntax_node_ptr = AstPtr::new(&block.into());
let expr_id = self
.alloc_expr(mk_block(block_id, statements.into_boxed_slice(), tail), syntax_node_ptr);
self.def_map = prev_def_map;
self.expander.module = prev_local_module;
self.current_block_legacy_macro_defs_count = prev_legacy_macros_count;
expr_id
}
fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
match expr {
Some(block) => self.collect_block(block),
None => self.missing_expr(),
}
}
fn collect_labelled_block_opt(
&mut self,
label: Option<(HygieneId, LabelId)>,
expr: Option<ast::BlockExpr>,
) -> ExprId {
match label {
Some((hygiene, label)) => {
self.with_labeled_rib(label, hygiene, |this| this.collect_block_opt(expr))
}
None => self.collect_block_opt(expr),
}
}
// region: patterns
fn collect_pat_top(&mut self, pat: Option<ast::Pat>) -> PatId {
match pat {
Some(pat) => self.collect_pat(pat, &mut BindingList::default()),
None => self.missing_pat(),
}
}
fn collect_pat(&mut self, pat: ast::Pat, binding_list: &mut BindingList) -> PatId {
let pattern = match &pat {
ast::Pat::IdentPat(bp) => {
let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
let hygiene = bp
.name()
.map(|name| self.hygiene_id_for(name.syntax().text_range().start()))
.unwrap_or(HygieneId::ROOT);
let annotation =
BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
let subpat = bp.pat().map(|subpat| self.collect_pat(subpat, binding_list));
let is_simple_ident_pat =
annotation == BindingAnnotation::Unannotated && subpat.is_none();
let (binding, pattern) = if is_simple_ident_pat {
// This could also be a single-segment path pattern. To
// decide that, we need to try resolving the name.
let (resolved, _) = self.def_map.resolve_path(
self.db,
self.expander.module.local_id,
&name.clone().into(),
BuiltinShadowMode::Other,
None,
);
match resolved.take_values() {
Some(ModuleDefId::ConstId(_)) => (None, Pat::Path(name.into())),
Some(ModuleDefId::EnumVariantId(_)) => {
// this is only really valid for unit variants, but
// shadowing other enum variants with a pattern is
// an error anyway
(None, Pat::Path(name.into()))
}
Some(ModuleDefId::AdtId(AdtId::StructId(s)))
if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
{
// Funnily enough, record structs *can* be shadowed
// by pattern bindings (but unit or tuple structs
// can't).
(None, Pat::Path(name.into()))
}
// shadowing statics is an error as well, so we just ignore that case here
_ => {
let id = binding_list.find(self, name, hygiene, annotation);
(Some(id), Pat::Bind { id, subpat })
}
}
} else {
let id = binding_list.find(self, name, hygiene, annotation);
(Some(id), Pat::Bind { id, subpat })
};
let ptr = AstPtr::new(&pat);
let pat = self.alloc_pat(pattern, ptr);
if let Some(binding_id) = binding {
self.add_definition_to_binding(binding_id, pat);
}
return pat;
}
ast::Pat::TupleStructPat(p) => {
let path = p.path().and_then(|path| self.parse_path(path)).map(Box::new);
let (args, ellipsis) = self.collect_tuple_pat(
p.fields(),
comma_follows_token(p.l_paren_token()),
binding_list,
);
Pat::TupleStruct { path, args, ellipsis }
}
ast::Pat::RefPat(p) => {
let pat = self.collect_pat_opt(p.pat(), binding_list);
let mutability = Mutability::from_mutable(p.mut_token().is_some());
Pat::Ref { pat, mutability }
}
ast::Pat::PathPat(p) => {
let path = p.path().and_then(|path| self.parse_path(path));
path.map(Pat::Path).unwrap_or(Pat::Missing)
}
ast::Pat::OrPat(p) => 'b: {
let prev_is_used = mem::take(&mut binding_list.is_used);
let prev_reject_new = mem::take(&mut binding_list.reject_new);
let mut pats = Vec::with_capacity(p.pats().count());
let mut it = p.pats();
let Some(first) = it.next() else {
break 'b Pat::Or(Box::new([]));
};
pats.push(self.collect_pat(first, binding_list));
binding_list.reject_new = true;
for rest in it {
for (_, it) in binding_list.is_used.iter_mut() {
*it = false;
}
pats.push(self.collect_pat(rest, binding_list));
for (&id, &is_used) in binding_list.is_used.iter() {
if !is_used {
self.body.bindings[id].problems =
Some(BindingProblems::NotBoundAcrossAll);
}
}
}
binding_list.reject_new = prev_reject_new;
let current_is_used = mem::replace(&mut binding_list.is_used, prev_is_used);
for (id, _) in current_is_used.into_iter() {
binding_list.check_is_used(self, id);
}
if let &[pat] = &*pats {
// Leading pipe without real OR pattern. Leaving an one-item OR pattern may confuse later stages.
return pat;
}
Pat::Or(pats.into())
}
ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat(), binding_list),
ast::Pat::TuplePat(p) => {
let (args, ellipsis) = self.collect_tuple_pat(
p.fields(),
comma_follows_token(p.l_paren_token()),
binding_list,
);
Pat::Tuple { args, ellipsis }
}
ast::Pat::WildcardPat(_) => Pat::Wild,
ast::Pat::RecordPat(p) => {
let path = p.path().and_then(|path| self.parse_path(path)).map(Box::new);
let record_pat_field_list =
&p.record_pat_field_list().expect("every struct should have a field list");
let args = record_pat_field_list
.fields()
.filter_map(|f| {
self.check_cfg(&f)?;
let ast_pat = f.pat()?;
let pat = self.collect_pat(ast_pat, binding_list);
let name = f.field_name()?.as_name();
let src = self.expander.in_file(AstPtr::new(&f).wrap_right());
self.source_map.pat_field_map_back.insert(pat, src);
Some(RecordFieldPat { name, pat })
})
.collect();
let ellipsis = record_pat_field_list.rest_pat().is_some();
Pat::Record { path, args, ellipsis }
}
ast::Pat::SlicePat(p) => {
let SlicePatComponents { prefix, slice, suffix } = p.components();
// FIXME properly handle `RestPat`
Pat::Slice {
prefix: prefix.into_iter().map(|p| self.collect_pat(p, binding_list)).collect(),
slice: slice.map(|p| self.collect_pat(p, binding_list)),
suffix: suffix.into_iter().map(|p| self.collect_pat(p, binding_list)).collect(),
}
}
ast::Pat::LiteralPat(lit) => 'b: {
let Some((hir_lit, ast_lit)) = pat_literal_to_hir(lit) else {
break 'b Pat::Missing;
};
let expr = Expr::Literal(hir_lit);
let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
let expr_id = self.alloc_expr(expr, expr_ptr);
Pat::Lit(expr_id)
}
ast::Pat::RestPat(_) => {
// `RestPat` requires special handling and should not be mapped
// to a Pat. Here we are using `Pat::Missing` as a fallback for
// when `RestPat` is mapped to `Pat`, which can easily happen
// when the source code being analyzed has a malformed pattern
// which includes `..` in a place where it isn't valid.
Pat::Missing
}
ast::Pat::BoxPat(boxpat) => {
let inner = self.collect_pat_opt(boxpat.pat(), binding_list);
Pat::Box { inner }
}
ast::Pat::ConstBlockPat(const_block_pat) => {
if let Some(block) = const_block_pat.block_expr() {
let expr_id = self.with_label_rib(RibKind::Constant, |this| {
let syntax_ptr = AstPtr::new(&block.clone().into());
this.collect_as_a_binding_owner_bad(
|this| this.collect_block(block),
syntax_ptr,
)
});
Pat::ConstBlock(expr_id)
} else {
Pat::Missing
}
}
ast::Pat::MacroPat(mac) => match mac.macro_call() {
Some(call) => {
let macro_ptr = AstPtr::new(&call);
let src = self.expander.in_file(AstPtr::new(&pat));
let pat =
self.collect_macro_call(call, macro_ptr, true, |this, expanded_pat| {
this.collect_pat_opt(expanded_pat, binding_list)
});
self.source_map.pat_map.insert(src, pat);
return pat;
}
None => Pat::Missing,
},
// FIXME: implement in a way that also builds source map and calculates assoc resolutions in type inference.
ast::Pat::RangePat(p) => {
let mut range_part_lower = |p: Option<ast::Pat>| {
p.and_then(|it| match &it {
ast::Pat::LiteralPat(it) => {
Some(Box::new(LiteralOrConst::Literal(pat_literal_to_hir(it)?.0)))
}
pat @ (ast::Pat::IdentPat(_) | ast::Pat::PathPat(_)) => {
let subpat = self.collect_pat(pat.clone(), binding_list);
Some(Box::new(LiteralOrConst::Const(subpat)))
}
_ => None,
})
};
let start = range_part_lower(p.start());
let end = range_part_lower(p.end());
Pat::Range { start, end }
}
};
let ptr = AstPtr::new(&pat);
self.alloc_pat(pattern, ptr)
}
fn collect_pat_opt(&mut self, pat: Option<ast::Pat>, binding_list: &mut BindingList) -> PatId {
match pat {
Some(pat) => self.collect_pat(pat, binding_list),
None => self.missing_pat(),
}
}
fn collect_tuple_pat(
&mut self,
args: AstChildren<ast::Pat>,
has_leading_comma: bool,
binding_list: &mut BindingList,
) -> (Box<[PatId]>, Option<u32>) {
let args: Vec<_> = args.map(|p| self.collect_pat_possibly_rest(p, binding_list)).collect();
// Find the location of the `..`, if there is one. Note that we do not
// consider the possibility of there being multiple `..` here.
let ellipsis = args.iter().position(|p| p.is_right()).map(|it| it as u32);
// We want to skip the `..` pattern here, since we account for it above.
let mut args: Vec<_> = args.into_iter().filter_map(Either::left).collect();
// if there is a leading comma, the user is most likely to type out a leading pattern
// so we insert a missing pattern at the beginning for IDE features
if has_leading_comma {
args.insert(0, self.missing_pat());
}
(args.into_boxed_slice(), ellipsis)
}
// `collect_pat` rejects `ast::Pat::RestPat`, but it should be handled in some cases that
// it is the macro expansion result of an arg sub-pattern in a slice or tuple pattern.
fn collect_pat_possibly_rest(
&mut self,
pat: ast::Pat,
binding_list: &mut BindingList,
) -> Either<PatId, ()> {
match &pat {
ast::Pat::RestPat(_) => Either::Right(()),
ast::Pat::MacroPat(mac) => match mac.macro_call() {
Some(call) => {
let macro_ptr = AstPtr::new(&call);
let src = self.expander.in_file(AstPtr::new(&pat));
let pat =
self.collect_macro_call(call, macro_ptr, true, |this, expanded_pat| {
if let Some(expanded_pat) = expanded_pat {
this.collect_pat_possibly_rest(expanded_pat, binding_list)
} else {
Either::Left(this.missing_pat())
}
});
if let Some(pat) = pat.left() {
self.source_map.pat_map.insert(src, pat);
}
pat
}
None => {
let ptr = AstPtr::new(&pat);
Either::Left(self.alloc_pat(Pat::Missing, ptr))
}
},
_ => Either::Left(self.collect_pat(pat, binding_list)),
}
}
// endregion: patterns
/// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
/// not.
fn check_cfg(&mut self, owner: &dyn ast::HasAttrs) -> Option<()> {
match self.expander.parse_attrs(self.db, owner).cfg() {
Some(cfg) => {
if self.expander.cfg_options().check(&cfg) != Some(false) {
return Some(());
}
self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode {
node: self.expander.in_file(SyntaxNodePtr::new(owner.syntax())),
cfg,
opts: self.expander.cfg_options().clone(),
});
None
}
None => Some(()),
}
}
fn add_definition_to_binding(&mut self, binding_id: BindingId, pat_id: PatId) {
self.source_map.binding_definitions.entry(binding_id).or_default().push(pat_id);
}
// region: labels
fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
let label = Label {
name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
};
self.alloc_label(label, AstPtr::new(&ast_label))
}
fn resolve_label(
&self,
lifetime: Option<ast::Lifetime>,
) -> Result<Option<LabelId>, BodyDiagnostic> {
let Some(lifetime) = lifetime else { return Ok(None) };
let (mut hygiene_id, mut hygiene_info) = match &self.current_span_map {
None => (HygieneId::ROOT, None),
Some(span_map) => {
let span = span_map.span_at(lifetime.syntax().text_range().start());
let ctx = self.db.lookup_intern_syntax_context(span.ctx);
let hygiene_id = HygieneId::new(ctx.opaque_and_semitransparent);
let hygiene_info = ctx.outer_expn.map(|expansion| {
let expansion = self.db.lookup_intern_macro_call(expansion);
(ctx.parent, expansion.def)
});
(hygiene_id, hygiene_info)
}
};
let name = Name::new_lifetime(&lifetime);
for (rib_idx, rib) in self.label_ribs.iter().enumerate().rev() {
match &rib.kind {
RibKind::Normal(label_name, id, label_hygiene) => {
if *label_name == name && *label_hygiene == hygiene_id {
return if self.is_label_valid_from_rib(rib_idx) {
Ok(Some(*id))
} else {
Err(BodyDiagnostic::UnreachableLabel {
name,
node: self.expander.in_file(AstPtr::new(&lifetime)),
})
};
}
}
RibKind::MacroDef(macro_id) => {
if let Some((parent_ctx, label_macro_id)) = hygiene_info {
if label_macro_id == **macro_id {
// A macro is allowed to refer to labels from before its declaration.
// Therefore, if we got to the rib of its declaration, give up its hygiene
// and use its parent expansion.
let parent_ctx = self.db.lookup_intern_syntax_context(parent_ctx);
hygiene_id = HygieneId::new(parent_ctx.opaque_and_semitransparent);
hygiene_info = parent_ctx.outer_expn.map(|expansion| {
let expansion = self.db.lookup_intern_macro_call(expansion);
(parent_ctx.parent, expansion.def)
});
}
}
}
_ => {}
}
}
Err(BodyDiagnostic::UndeclaredLabel {
name,
node: self.expander.in_file(AstPtr::new(&lifetime)),
})
}
fn is_label_valid_from_rib(&self, rib_index: usize) -> bool {
!self.label_ribs[rib_index + 1..].iter().any(|rib| rib.kind.is_label_barrier())
}
fn pop_label_rib(&mut self) {
// We need to pop all macro defs, plus one rib.
while let Some(LabelRib { kind: RibKind::MacroDef(_) }) = self.label_ribs.pop() {
// Do nothing.
}
}
fn with_label_rib<T>(&mut self, kind: RibKind, f: impl FnOnce(&mut Self) -> T) -> T {
self.label_ribs.push(LabelRib::new(kind));
let res = f(self);
self.pop_label_rib();
res
}
fn with_labeled_rib<T>(
&mut self,
label: LabelId,
hygiene: HygieneId,
f: impl FnOnce(&mut Self) -> T,
) -> T {
self.label_ribs.push(LabelRib::new(RibKind::Normal(
self.body[label].name.clone(),
label,
hygiene,
)));
let res = f(self);
self.pop_label_rib();
res
}
fn with_opt_labeled_rib<T>(
&mut self,
label: Option<(HygieneId, LabelId)>,
f: impl FnOnce(&mut Self) -> T,
) -> T {
match label {
None => f(self),
Some((hygiene, label)) => self.with_labeled_rib(label, hygiene, f),
}
}
// endregion: labels
// region: format
fn expand_macros_to_string(&mut self, expr: ast::Expr) -> Option<(ast::String, bool)> {
let m = match expr {
ast::Expr::MacroExpr(m) => m,
ast::Expr::Literal(l) => {
return match l.kind() {
ast::LiteralKind::String(s) => Some((s, true)),
_ => None,
}
}
_ => return None,
};
let e = m.macro_call()?;
let macro_ptr = AstPtr::new(&e);
let (exp, _) = self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
expansion.and_then(|it| this.expand_macros_to_string(it))
})?;
Some((exp, false))
}
fn collect_format_args(
&mut self,
f: ast::FormatArgsExpr,
syntax_ptr: AstPtr<ast::Expr>,
) -> ExprId {
let mut args = FormatArgumentsCollector::new();
f.args().for_each(|arg| {
args.add(FormatArgument {
kind: match arg.name() {
Some(name) => FormatArgumentKind::Named(name.as_name()),
None => FormatArgumentKind::Normal,
},
expr: self.collect_expr_opt(arg.expr()),
});
});
let template = f.template();
let fmt_snippet = template.as_ref().and_then(|it| match it {
ast::Expr::Literal(literal) => match literal.kind() {
ast::LiteralKind::String(s) => Some(s.text().to_owned()),
_ => None,
},
_ => None,
});
let mut mappings = vec![];
let (fmt, hygiene) = match template.and_then(|it| self.expand_macros_to_string(it)) {
Some((s, is_direct_literal)) => {
let call_ctx = self.expander.syntax_context();
let hygiene = self.hygiene_id_for(s.syntax().text_range().start());
let fmt = format_args::parse(
&s,
fmt_snippet,
args,
is_direct_literal,
|name| {
let expr_id = self.alloc_expr_desugared(Expr::Path(Path::from(name)));
if !hygiene.is_root() {
self.body.expr_hygiene.insert(expr_id, hygiene);
}
expr_id
},
|name, span| {
if let Some(span) = span {
mappings.push((span, name))
}
},
call_ctx,
);
(fmt, hygiene)
}
None => (
FormatArgs {
template: Default::default(),
arguments: args.finish(),
orphans: Default::default(),
},
HygieneId::ROOT,
),
};
// Create a list of all _unique_ (argument, format trait) combinations.
// E.g. "{0} {0:x} {0} {1}" -> [(0, Display), (0, LowerHex), (1, Display)]
let mut argmap = FxIndexSet::default();
for piece in fmt.template.iter() {
let FormatArgsPiece::Placeholder(placeholder) = piece else { continue };
if let Ok(index) = placeholder.argument.index {
argmap.insert((index, ArgumentType::Format(placeholder.format_trait)));
}
}
let lit_pieces = fmt
.template
.iter()
.enumerate()
.filter_map(|(i, piece)| {
match piece {
FormatArgsPiece::Literal(s) => {
Some(self.alloc_expr_desugared(Expr::Literal(Literal::String(s.clone()))))
}
&FormatArgsPiece::Placeholder(_) => {
// Inject empty string before placeholders when not already preceded by a literal piece.
if i == 0 || matches!(fmt.template[i - 1], FormatArgsPiece::Placeholder(_))
{
Some(self.alloc_expr_desugared(Expr::Literal(Literal::String(
Symbol::empty(),
))))
} else {
None
}
}
}
})
.collect();
let lit_pieces =
self.alloc_expr_desugared(Expr::Array(Array::ElementList { elements: lit_pieces }));
let lit_pieces = self.alloc_expr_desugared(Expr::Ref {
expr: lit_pieces,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
});
let format_options = {
// Generate:
// &[format_spec_0, format_spec_1, format_spec_2]
let elements = fmt
.template
.iter()
.filter_map(|piece| {
let FormatArgsPiece::Placeholder(placeholder) = piece else { return None };
Some(self.make_format_spec(placeholder, &mut argmap))
})
.collect();
let array = self.alloc_expr_desugared(Expr::Array(Array::ElementList { elements }));
self.alloc_expr_desugared(Expr::Ref {
expr: array,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
})
};
let arguments = &*fmt.arguments.arguments;
let args = if arguments.is_empty() {
let expr = self
.alloc_expr_desugared(Expr::Array(Array::ElementList { elements: Box::default() }));
self.alloc_expr_desugared(Expr::Ref {
expr,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
})
} else {
// Generate:
// &match (&arg0, &arg1, &…) {
// args => [
// <core::fmt::Argument>::new_display(args.0),
// <core::fmt::Argument>::new_lower_hex(args.1),
// <core::fmt::Argument>::new_debug(args.0),
// …
// ]
// }
let args = argmap
.iter()
.map(|&(arg_index, ty)| {
let arg = self.alloc_expr_desugared(Expr::Ref {
expr: arguments[arg_index].expr,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
});
self.make_argument(arg, ty)
})
.collect();
let array =
self.alloc_expr_desugared(Expr::Array(Array::ElementList { elements: args }));
self.alloc_expr_desugared(Expr::Ref {
expr: array,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
})
};
// Generate:
// <core::fmt::Arguments>::new_v1_formatted(
// lit_pieces,
// args,
// format_options,
// unsafe { ::core::fmt::UnsafeArg::new() }
// )
let Some(new_v1_formatted) = LangItem::FormatArguments.ty_rel_path(
self.db,
self.krate,
Name::new_symbol_root(sym::new_v1_formatted.clone()),
) else {
return self.missing_expr();
};
let Some(unsafe_arg_new) = LangItem::FormatUnsafeArg.ty_rel_path(
self.db,
self.krate,
Name::new_symbol_root(sym::new.clone()),
) else {
return self.missing_expr();
};
let new_v1_formatted = self.alloc_expr_desugared(Expr::Path(new_v1_formatted));
let unsafe_arg_new = self.alloc_expr_desugared(Expr::Path(unsafe_arg_new));
let unsafe_arg_new =
self.alloc_expr_desugared(Expr::Call { callee: unsafe_arg_new, args: Box::default() });
let unsafe_arg_new = self.alloc_expr_desugared(Expr::Unsafe {
id: None,
// We collect the unused expressions here so that we still infer them instead of
// dropping them out of the expression tree
statements: fmt
.orphans
.into_iter()
.map(|expr| Statement::Expr { expr, has_semi: true })
.collect(),
tail: Some(unsafe_arg_new),
});
let idx = self.alloc_expr(
Expr::Call {
callee: new_v1_formatted,
args: Box::new([lit_pieces, args, format_options, unsafe_arg_new]),
},
syntax_ptr,
);
self.source_map
.template_map
.get_or_insert_with(Default::default)
.0
.insert(idx, (hygiene, mappings));
idx
}
/// Generate a hir expression for a format_args placeholder specification.
///
/// Generates
///
/// ```text
/// <core::fmt::rt::Placeholder::new(
/// …usize, // position
/// '…', // fill
/// <core::fmt::rt::Alignment>::…, // alignment
/// …u32, // flags
/// <core::fmt::rt::Count::…>, // width
/// <core::fmt::rt::Count::…>, // precision
/// )
/// ```
fn make_format_spec(
&mut self,
placeholder: &FormatPlaceholder,
argmap: &mut FxIndexSet<(usize, ArgumentType)>,
) -> ExprId {
let position = match placeholder.argument.index {
Ok(arg_index) => {
let (i, _) =
argmap.insert_full((arg_index, ArgumentType::Format(placeholder.format_trait)));
self.alloc_expr_desugared(Expr::Literal(Literal::Uint(
i as u128,
Some(BuiltinUint::Usize),
)))
}
Err(_) => self.missing_expr(),
};
let &FormatOptions {
ref width,
ref precision,
alignment,
fill,
sign,
alternate,
zero_pad,
debug_hex,
} = &placeholder.format_options;
let fill = self.alloc_expr_desugared(Expr::Literal(Literal::Char(fill.unwrap_or(' '))));
let align = {
let align = LangItem::FormatAlignment.ty_rel_path(
self.db,
self.krate,
match alignment {
Some(FormatAlignment::Left) => Name::new_symbol_root(sym::Left.clone()),
Some(FormatAlignment::Right) => Name::new_symbol_root(sym::Right.clone()),
Some(FormatAlignment::Center) => Name::new_symbol_root(sym::Center.clone()),
None => Name::new_symbol_root(sym::Unknown.clone()),
},
);
match align {
Some(path) => self.alloc_expr_desugared(Expr::Path(path)),
None => self.missing_expr(),
}
};
// This needs to match `Flag` in library/core/src/fmt/rt.rs.
let flags: u32 = ((sign == Some(FormatSign::Plus)) as u32)
| ((sign == Some(FormatSign::Minus)) as u32) << 1
| (alternate as u32) << 2
| (zero_pad as u32) << 3
| ((debug_hex == Some(FormatDebugHex::Lower)) as u32) << 4
| ((debug_hex == Some(FormatDebugHex::Upper)) as u32) << 5;
let flags = self.alloc_expr_desugared(Expr::Literal(Literal::Uint(
flags as u128,
Some(BuiltinUint::U32),
)));
let precision = self.make_count(precision, argmap);
let width = self.make_count(width, argmap);
let format_placeholder_new = {
let format_placeholder_new = LangItem::FormatPlaceholder.ty_rel_path(
self.db,
self.krate,
Name::new_symbol_root(sym::new.clone()),
);
match format_placeholder_new {
Some(path) => self.alloc_expr_desugared(Expr::Path(path)),
None => self.missing_expr(),
}
};
self.alloc_expr_desugared(Expr::Call {
callee: format_placeholder_new,
args: Box::new([position, fill, align, flags, precision, width]),
})
}
/// Generate a hir expression for a format_args Count.
///
/// Generates:
///
/// ```text
/// <core::fmt::rt::Count>::Is(…)
/// ```
///
/// or
///
/// ```text
/// <core::fmt::rt::Count>::Param(…)
/// ```
///
/// or
///
/// ```text
/// <core::fmt::rt::Count>::Implied
/// ```
fn make_count(
&mut self,
count: &Option<FormatCount>,
argmap: &mut FxIndexSet<(usize, ArgumentType)>,
) -> ExprId {
match count {
Some(FormatCount::Literal(n)) => {
let args = self.alloc_expr_desugared(Expr::Literal(Literal::Uint(
*n as u128,
Some(BuiltinUint::Usize),
)));
let count_is = match LangItem::FormatCount.ty_rel_path(
self.db,
self.krate,
Name::new_symbol_root(sym::Is.clone()),
) {
Some(count_is) => self.alloc_expr_desugared(Expr::Path(count_is)),
None => self.missing_expr(),
};
self.alloc_expr_desugared(Expr::Call { callee: count_is, args: Box::new([args]) })
}
Some(FormatCount::Argument(arg)) => {
if let Ok(arg_index) = arg.index {
let (i, _) = argmap.insert_full((arg_index, ArgumentType::Usize));
let args = self.alloc_expr_desugared(Expr::Literal(Literal::Uint(
i as u128,
Some(BuiltinUint::Usize),
)));
let count_param = match LangItem::FormatCount.ty_rel_path(
self.db,
self.krate,
Name::new_symbol_root(sym::Param.clone()),
) {
Some(count_param) => self.alloc_expr_desugared(Expr::Path(count_param)),
None => self.missing_expr(),
};
self.alloc_expr_desugared(Expr::Call {
callee: count_param,
args: Box::new([args]),
})
} else {
// FIXME: This drops arg causing it to potentially not be resolved/type checked
// when typing?
self.missing_expr()
}
}
None => match LangItem::FormatCount.ty_rel_path(
self.db,
self.krate,
Name::new_symbol_root(sym::Implied.clone()),
) {
Some(count_param) => self.alloc_expr_desugared(Expr::Path(count_param)),
None => self.missing_expr(),
},
}
}
/// Generate a hir expression representing an argument to a format_args invocation.
///
/// Generates:
///
/// ```text
/// <core::fmt::Argument>::new_…(arg)
/// ```
fn make_argument(&mut self, arg: ExprId, ty: ArgumentType) -> ExprId {
use ArgumentType::*;
use FormatTrait::*;
let new_fn = match LangItem::FormatArgument.ty_rel_path(
self.db,
self.krate,
Name::new_symbol_root(match ty {
Format(Display) => sym::new_display.clone(),
Format(Debug) => sym::new_debug.clone(),
Format(LowerExp) => sym::new_lower_exp.clone(),
Format(UpperExp) => sym::new_upper_exp.clone(),
Format(Octal) => sym::new_octal.clone(),
Format(Pointer) => sym::new_pointer.clone(),
Format(Binary) => sym::new_binary.clone(),
Format(LowerHex) => sym::new_lower_hex.clone(),
Format(UpperHex) => sym::new_upper_hex.clone(),
Usize => sym::from_usize.clone(),
}),
) {
Some(new_fn) => self.alloc_expr_desugared(Expr::Path(new_fn)),
None => self.missing_expr(),
};
self.alloc_expr_desugared(Expr::Call { callee: new_fn, args: Box::new([arg]) })
}
// endregion: format
fn lang_path(&self, lang: LangItem) -> Option<Path> {
lang.path(self.db, self.krate)
}
}
fn pat_literal_to_hir(lit: &ast::LiteralPat) -> Option<(Literal, ast::Literal)> {
let ast_lit = lit.literal()?;
let mut hir_lit: Literal = ast_lit.kind().into();
if lit.minus_token().is_some() {
hir_lit = hir_lit.negate()?;
}
Some((hir_lit, ast_lit))
}
impl ExprCollector<'_> {
fn alloc_expr(&mut self, expr: Expr, ptr: ExprPtr) -> ExprId {
let src = self.expander.in_file(ptr);
let id = self.body.exprs.alloc(expr);
self.source_map.expr_map_back.insert(id, src);
self.source_map.expr_map.insert(src, id.into());
id
}
// FIXME: desugared exprs don't have ptr, that's wrong and should be fixed.
// Migrate to alloc_expr_desugared_with_ptr and then rename back
fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
self.body.exprs.alloc(expr)
}
fn alloc_expr_desugared_with_ptr(&mut self, expr: Expr, ptr: ExprPtr) -> ExprId {
let src = self.expander.in_file(ptr);
let id = self.body.exprs.alloc(expr);
self.source_map.expr_map_back.insert(id, src);
// We intentionally don't fill this as it could overwrite a non-desugared entry
// self.source_map.expr_map.insert(src, id);
id
}
fn missing_expr(&mut self) -> ExprId {
self.alloc_expr_desugared(Expr::Missing)
}
fn alloc_binding(&mut self, name: Name, mode: BindingAnnotation) -> BindingId {
let binding = self.body.bindings.alloc(Binding { name, mode, problems: None });
if let Some(owner) = self.current_binding_owner {
self.body.binding_owners.insert(binding, owner);
}
binding
}
fn alloc_pat_from_expr(&mut self, pat: Pat, ptr: ExprPtr) -> PatId {
let src = self.expander.in_file(ptr);
let id = self.body.pats.alloc(pat);
self.source_map.expr_map.insert(src, id.into());
self.source_map.pat_map_back.insert(id, src.map(AstPtr::wrap_left));
id
}
fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
let src = self.expander.in_file(ptr);
let id = self.body.pats.alloc(pat);
self.source_map.pat_map_back.insert(id, src.map(AstPtr::wrap_right));
self.source_map.pat_map.insert(src, id);
id
}
// FIXME: desugared pats don't have ptr, that's wrong and should be fixed somehow.
fn alloc_pat_desugared(&mut self, pat: Pat) -> PatId {
self.body.pats.alloc(pat)
}
fn missing_pat(&mut self) -> PatId {
self.body.pats.alloc(Pat::Missing)
}
fn alloc_label(&mut self, label: Label, ptr: LabelPtr) -> LabelId {
let src = self.expander.in_file(ptr);
let id = self.body.labels.alloc(label);
self.source_map.label_map_back.insert(id, src);
self.source_map.label_map.insert(src, id);
id
}
// FIXME: desugared labels don't have ptr, that's wrong and should be fixed somehow.
fn alloc_label_desugared(&mut self, label: Label) -> LabelId {
self.body.labels.alloc(label)
}
fn is_lowering_awaitable_block(&self) -> &Awaitable {
self.awaitable_context.as_ref().unwrap_or(&Awaitable::No("unknown"))
}
fn with_awaitable_block<T>(
&mut self,
awaitable: Awaitable,
f: impl FnOnce(&mut Self) -> T,
) -> T {
let orig = self.awaitable_context.replace(awaitable);
let res = f(self);
self.awaitable_context = orig;
res
}
/// If this returns `HygieneId::ROOT`, do not allocate to save space.
fn hygiene_id_for(&self, span_start: TextSize) -> HygieneId {
match &self.current_span_map {
None => HygieneId::ROOT,
Some(span_map) => {
let ctx = span_map.span_at(span_start).ctx;
HygieneId(self.db.lookup_intern_syntax_context(ctx).opaque_and_semitransparent)
}
}
}
}
fn comma_follows_token(t: Option<syntax::SyntaxToken>) -> bool {
(|| syntax::algo::skip_trivia_token(t?.next_token()?, syntax::Direction::Next))()
.map_or(false, |it| it.kind() == syntax::T![,])
}
#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
enum ArgumentType {
Format(FormatTrait),
Usize,
}