rust/crates/hir-expand/src/lib.rs

869 lines
31 KiB
Rust

//! `hir_expand` deals with macro expansion.
//!
//! Specifically, it implements a concept of `MacroFile` -- a file whose syntax
//! tree originates not from the text of some `FileId`, but from some macro
//! expansion.
#![warn(rust_2018_idioms, unused_lifetimes)]
pub mod ast_id_map;
pub mod attrs;
pub mod builtin_attr_macro;
pub mod builtin_derive_macro;
pub mod builtin_fn_macro;
pub mod db;
pub mod eager;
pub mod files;
pub mod change;
pub mod hygiene;
pub mod mod_path;
pub mod name;
pub mod proc_macro;
pub mod quote;
pub mod span_map;
mod fixup;
use attrs::collect_attrs;
use triomphe::Arc;
use std::{fmt, hash::Hash};
use base_db::{CrateId, Edition, FileId};
use either::Either;
use span::{FileRange, HirFileIdRepr, Span, SyntaxContextId};
use syntax::{
ast::{self, AstNode},
SyntaxNode, SyntaxToken, TextRange, TextSize,
};
use crate::{
attrs::AttrId,
builtin_attr_macro::BuiltinAttrExpander,
builtin_derive_macro::BuiltinDeriveExpander,
builtin_fn_macro::{BuiltinFnLikeExpander, EagerExpander},
db::{ExpandDatabase, TokenExpander},
fixup::SyntaxFixupUndoInfo,
hygiene::SyntaxContextData,
mod_path::ModPath,
proc_macro::{CustomProcMacroExpander, ProcMacroKind},
span_map::{ExpansionSpanMap, SpanMap},
};
pub use crate::ast_id_map::{AstId, ErasedAstId, ErasedFileAstId};
pub use crate::files::{InFile, InMacroFile, InRealFile};
pub use mbe::ValueResult;
pub use span::{HirFileId, MacroCallId, MacroFileId};
pub type DeclarativeMacro = ::mbe::DeclarativeMacro<tt::Span>;
pub mod tt {
pub use span::Span;
pub use tt::{DelimiterKind, Spacing};
pub type Delimiter = ::tt::Delimiter<Span>;
pub type DelimSpan = ::tt::DelimSpan<Span>;
pub type Subtree = ::tt::Subtree<Span>;
pub type Leaf = ::tt::Leaf<Span>;
pub type Literal = ::tt::Literal<Span>;
pub type Punct = ::tt::Punct<Span>;
pub type Ident = ::tt::Ident<Span>;
pub type TokenTree = ::tt::TokenTree<Span>;
}
#[macro_export]
macro_rules! impl_intern_lookup {
($db:ident, $id:ident, $loc:ident, $intern:ident, $lookup:ident) => {
impl $crate::Intern for $loc {
type Database<'db> = dyn $db + 'db;
type ID = $id;
fn intern(self, db: &Self::Database<'_>) -> $id {
db.$intern(self)
}
}
impl $crate::Lookup for $id {
type Database<'db> = dyn $db + 'db;
type Data = $loc;
fn lookup(&self, db: &Self::Database<'_>) -> $loc {
db.$lookup(*self)
}
}
};
}
// ideally these would be defined in base-db, but the orphan rule doesn't let us
pub trait Intern {
type Database<'db>: ?Sized;
type ID;
fn intern(self, db: &Self::Database<'_>) -> Self::ID;
}
pub trait Lookup {
type Database<'db>: ?Sized;
type Data;
fn lookup(&self, db: &Self::Database<'_>) -> Self::Data;
}
impl_intern_lookup!(
ExpandDatabase,
MacroCallId,
MacroCallLoc,
intern_macro_call,
lookup_intern_macro_call
);
impl_intern_lookup!(
ExpandDatabase,
SyntaxContextId,
SyntaxContextData,
intern_syntax_context,
lookup_intern_syntax_context
);
pub type ExpandResult<T> = ValueResult<T, ExpandError>;
#[derive(Debug, PartialEq, Eq, Clone, Hash)]
pub enum ExpandError {
UnresolvedProcMacro(CrateId),
Mbe(mbe::ExpandError),
RecursionOverflowPoisoned,
Other(Box<Box<str>>),
ProcMacroPanic(Box<Box<str>>),
}
impl ExpandError {
pub fn other(msg: impl Into<Box<str>>) -> Self {
ExpandError::Other(Box::new(msg.into()))
}
}
impl From<mbe::ExpandError> for ExpandError {
fn from(mbe: mbe::ExpandError) -> Self {
Self::Mbe(mbe)
}
}
impl fmt::Display for ExpandError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
ExpandError::UnresolvedProcMacro(_) => f.write_str("unresolved proc-macro"),
ExpandError::Mbe(it) => it.fmt(f),
ExpandError::RecursionOverflowPoisoned => {
f.write_str("overflow expanding the original macro")
}
ExpandError::ProcMacroPanic(it) => {
f.write_str("proc-macro panicked: ")?;
f.write_str(it)
}
ExpandError::Other(it) => f.write_str(it),
}
}
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct MacroCallLoc {
pub def: MacroDefId,
pub krate: CrateId,
/// Some if this is a macro call for an eager macro. Note that this is `None`
/// for the eager input macro file.
// FIXME: This seems bad to save in an interned structure
eager: Option<Arc<EagerCallInfo>>,
pub kind: MacroCallKind,
pub call_site: Span,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct MacroDefId {
pub krate: CrateId,
pub edition: Edition,
pub kind: MacroDefKind,
pub local_inner: bool,
pub allow_internal_unsafe: bool,
pub span: Span,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum MacroDefKind {
Declarative(AstId<ast::Macro>),
BuiltIn(BuiltinFnLikeExpander, AstId<ast::Macro>),
BuiltInAttr(BuiltinAttrExpander, AstId<ast::Macro>),
BuiltInDerive(BuiltinDeriveExpander, AstId<ast::Macro>),
BuiltInEager(EagerExpander, AstId<ast::Macro>),
ProcMacro(CustomProcMacroExpander, ProcMacroKind, AstId<ast::Fn>),
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct EagerCallInfo {
/// The expanded argument of the eager macro.
arg: Arc<tt::Subtree>,
/// Call id of the eager macro's input file (this is the macro file for its fully expanded input).
arg_id: MacroCallId,
error: Option<ExpandError>,
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum MacroCallKind {
FnLike {
ast_id: AstId<ast::MacroCall>,
expand_to: ExpandTo,
},
Derive {
ast_id: AstId<ast::Adt>,
/// Syntactical index of the invoking `#[derive]` attribute.
///
/// Outer attributes are counted first, then inner attributes. This does not support
/// out-of-line modules, which may have attributes spread across 2 files!
derive_attr_index: AttrId,
/// Index of the derive macro in the derive attribute
derive_index: u32,
},
Attr {
ast_id: AstId<ast::Item>,
// FIXME: This is being interned, subtrees can very quickly differ just slightly causing
// leakage problems here
attr_args: Option<Arc<tt::Subtree>>,
/// Syntactical index of the invoking `#[attribute]`.
///
/// Outer attributes are counted first, then inner attributes. This does not support
/// out-of-line modules, which may have attributes spread across 2 files!
invoc_attr_index: AttrId,
},
}
pub trait HirFileIdExt {
/// Returns the original file of this macro call hierarchy.
fn original_file(self, db: &dyn ExpandDatabase) -> FileId;
/// Returns the original file of this macro call hierarchy while going into the included file if
/// one of the calls comes from an `include!``.
fn original_file_respecting_includes(self, db: &dyn ExpandDatabase) -> FileId;
/// If this is a macro call, returns the syntax node of the very first macro call this file resides in.
fn original_call_node(self, db: &dyn ExpandDatabase) -> Option<InRealFile<SyntaxNode>>;
/// Return expansion information if it is a macro-expansion file
fn expansion_info(self, db: &dyn ExpandDatabase) -> Option<ExpansionInfo>;
fn as_builtin_derive_attr_node(&self, db: &dyn ExpandDatabase) -> Option<InFile<ast::Attr>>;
}
impl HirFileIdExt for HirFileId {
fn original_file(self, db: &dyn ExpandDatabase) -> FileId {
let mut file_id = self;
loop {
match file_id.repr() {
HirFileIdRepr::FileId(id) => break id,
HirFileIdRepr::MacroFile(MacroFileId { macro_call_id }) => {
file_id = macro_call_id.lookup(db).kind.file_id();
}
}
}
}
fn original_file_respecting_includes(mut self, db: &dyn ExpandDatabase) -> FileId {
loop {
match self.repr() {
HirFileIdRepr::FileId(id) => break id,
HirFileIdRepr::MacroFile(file) => {
let loc = db.lookup_intern_macro_call(file.macro_call_id);
if loc.def.is_include() {
if let Some(eager) = &loc.eager {
if let Ok(it) = builtin_fn_macro::include_input_to_file_id(
db,
file.macro_call_id,
&eager.arg,
) {
break it;
}
}
}
self = loc.kind.file_id();
}
}
}
}
fn original_call_node(self, db: &dyn ExpandDatabase) -> Option<InRealFile<SyntaxNode>> {
let mut call = db.lookup_intern_macro_call(self.macro_file()?.macro_call_id).to_node(db);
loop {
match call.file_id.repr() {
HirFileIdRepr::FileId(file_id) => {
break Some(InRealFile { file_id, value: call.value })
}
HirFileIdRepr::MacroFile(MacroFileId { macro_call_id }) => {
call = db.lookup_intern_macro_call(macro_call_id).to_node(db);
}
}
}
}
/// Return expansion information if it is a macro-expansion file
fn expansion_info(self, db: &dyn ExpandDatabase) -> Option<ExpansionInfo> {
Some(ExpansionInfo::new(db, self.macro_file()?))
}
fn as_builtin_derive_attr_node(&self, db: &dyn ExpandDatabase) -> Option<InFile<ast::Attr>> {
let macro_file = self.macro_file()?;
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
let attr = match loc.def.kind {
MacroDefKind::BuiltInDerive(..) => loc.to_node(db),
_ => return None,
};
Some(attr.with_value(ast::Attr::cast(attr.value.clone())?))
}
}
pub trait MacroFileIdExt {
fn expansion_level(self, db: &dyn ExpandDatabase) -> u32;
/// If this is a macro call, returns the syntax node of the call.
fn call_node(self, db: &dyn ExpandDatabase) -> InFile<SyntaxNode>;
fn parent(self, db: &dyn ExpandDatabase) -> HirFileId;
fn expansion_info(self, db: &dyn ExpandDatabase) -> ExpansionInfo;
fn is_builtin_derive(&self, db: &dyn ExpandDatabase) -> bool;
fn is_custom_derive(&self, db: &dyn ExpandDatabase) -> bool;
/// Return whether this file is an include macro
fn is_include_macro(&self, db: &dyn ExpandDatabase) -> bool;
fn is_eager(&self, db: &dyn ExpandDatabase) -> bool;
/// Return whether this file is an attr macro
fn is_attr_macro(&self, db: &dyn ExpandDatabase) -> bool;
/// Return whether this file is the pseudo expansion of the derive attribute.
/// See [`crate::builtin_attr_macro::derive_attr_expand`].
fn is_derive_attr_pseudo_expansion(&self, db: &dyn ExpandDatabase) -> bool;
}
impl MacroFileIdExt for MacroFileId {
fn call_node(self, db: &dyn ExpandDatabase) -> InFile<SyntaxNode> {
db.lookup_intern_macro_call(self.macro_call_id).to_node(db)
}
fn expansion_level(self, db: &dyn ExpandDatabase) -> u32 {
let mut level = 0;
let mut macro_file = self;
loop {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
level += 1;
macro_file = match loc.kind.file_id().repr() {
HirFileIdRepr::FileId(_) => break level,
HirFileIdRepr::MacroFile(it) => it,
};
}
}
fn parent(self, db: &dyn ExpandDatabase) -> HirFileId {
self.macro_call_id.lookup(db).kind.file_id()
}
/// Return expansion information if it is a macro-expansion file
fn expansion_info(self, db: &dyn ExpandDatabase) -> ExpansionInfo {
ExpansionInfo::new(db, self)
}
fn is_custom_derive(&self, db: &dyn ExpandDatabase) -> bool {
matches!(
db.lookup_intern_macro_call(self.macro_call_id).def.kind,
MacroDefKind::ProcMacro(_, ProcMacroKind::CustomDerive, _)
)
}
fn is_builtin_derive(&self, db: &dyn ExpandDatabase) -> bool {
matches!(
db.lookup_intern_macro_call(self.macro_call_id).def.kind,
MacroDefKind::BuiltInDerive(..)
)
}
fn is_include_macro(&self, db: &dyn ExpandDatabase) -> bool {
db.lookup_intern_macro_call(self.macro_call_id).def.is_include()
}
fn is_eager(&self, db: &dyn ExpandDatabase) -> bool {
let loc: MacroCallLoc = db.lookup_intern_macro_call(self.macro_call_id);
matches!(loc.def.kind, MacroDefKind::BuiltInEager(..))
}
fn is_attr_macro(&self, db: &dyn ExpandDatabase) -> bool {
let loc: MacroCallLoc = db.lookup_intern_macro_call(self.macro_call_id);
matches!(loc.kind, MacroCallKind::Attr { .. })
}
fn is_derive_attr_pseudo_expansion(&self, db: &dyn ExpandDatabase) -> bool {
let loc: MacroCallLoc = db.lookup_intern_macro_call(self.macro_call_id);
loc.def.is_attribute_derive()
}
}
impl MacroDefId {
pub fn as_lazy_macro(
self,
db: &dyn ExpandDatabase,
krate: CrateId,
kind: MacroCallKind,
call_site: Span,
) -> MacroCallId {
MacroCallLoc { def: self, krate, eager: None, kind, call_site }.intern(db)
}
pub fn definition_range(&self, db: &dyn ExpandDatabase) -> InFile<TextRange> {
match self.kind {
MacroDefKind::Declarative(id)
| MacroDefKind::BuiltIn(_, id)
| MacroDefKind::BuiltInAttr(_, id)
| MacroDefKind::BuiltInDerive(_, id)
| MacroDefKind::BuiltInEager(_, id) => {
id.with_value(db.ast_id_map(id.file_id).get(id.value).text_range())
}
MacroDefKind::ProcMacro(_, _, id) => {
id.with_value(db.ast_id_map(id.file_id).get(id.value).text_range())
}
}
}
pub fn ast_id(&self) -> Either<AstId<ast::Macro>, AstId<ast::Fn>> {
match self.kind {
MacroDefKind::ProcMacro(.., id) => Either::Right(id),
MacroDefKind::Declarative(id)
| MacroDefKind::BuiltIn(_, id)
| MacroDefKind::BuiltInAttr(_, id)
| MacroDefKind::BuiltInDerive(_, id)
| MacroDefKind::BuiltInEager(_, id) => Either::Left(id),
}
}
pub fn is_proc_macro(&self) -> bool {
matches!(self.kind, MacroDefKind::ProcMacro(..))
}
pub fn is_attribute(&self) -> bool {
matches!(
self.kind,
MacroDefKind::BuiltInAttr(..) | MacroDefKind::ProcMacro(_, ProcMacroKind::Attr, _)
)
}
pub fn is_derive(&self) -> bool {
matches!(
self.kind,
MacroDefKind::BuiltInDerive(..)
| MacroDefKind::ProcMacro(_, ProcMacroKind::CustomDerive, _)
)
}
pub fn is_fn_like(&self) -> bool {
matches!(
self.kind,
MacroDefKind::BuiltIn(..)
| MacroDefKind::ProcMacro(_, ProcMacroKind::FuncLike, _)
| MacroDefKind::BuiltInEager(..)
| MacroDefKind::Declarative(..)
)
}
pub fn is_attribute_derive(&self) -> bool {
matches!(self.kind, MacroDefKind::BuiltInAttr(expander, ..) if expander.is_derive())
}
pub fn is_include(&self) -> bool {
matches!(self.kind, MacroDefKind::BuiltInEager(expander, ..) if expander.is_include())
}
}
impl MacroCallLoc {
pub fn to_node(&self, db: &dyn ExpandDatabase) -> InFile<SyntaxNode> {
match self.kind {
MacroCallKind::FnLike { ast_id, .. } => {
ast_id.with_value(ast_id.to_node(db).syntax().clone())
}
MacroCallKind::Derive { ast_id, derive_attr_index, .. } => {
// FIXME: handle `cfg_attr`
ast_id.with_value(ast_id.to_node(db)).map(|it| {
collect_attrs(&it)
.nth(derive_attr_index.ast_index())
.and_then(|it| match it.1 {
Either::Left(attr) => Some(attr.syntax().clone()),
Either::Right(_) => None,
})
.unwrap_or_else(|| it.syntax().clone())
})
}
MacroCallKind::Attr { ast_id, invoc_attr_index, .. } => {
if self.def.is_attribute_derive() {
// FIXME: handle `cfg_attr`
ast_id.with_value(ast_id.to_node(db)).map(|it| {
collect_attrs(&it)
.nth(invoc_attr_index.ast_index())
.and_then(|it| match it.1 {
Either::Left(attr) => Some(attr.syntax().clone()),
Either::Right(_) => None,
})
.unwrap_or_else(|| it.syntax().clone())
})
} else {
ast_id.with_value(ast_id.to_node(db).syntax().clone())
}
}
}
}
fn expand_to(&self) -> ExpandTo {
match self.kind {
MacroCallKind::FnLike { expand_to, .. } => expand_to,
MacroCallKind::Derive { .. } => ExpandTo::Items,
MacroCallKind::Attr { .. } if self.def.is_attribute_derive() => ExpandTo::Items,
MacroCallKind::Attr { .. } => {
// FIXME(stmt_expr_attributes)
ExpandTo::Items
}
}
}
}
impl MacroCallKind {
fn descr(&self) -> &'static str {
match self {
MacroCallKind::FnLike { .. } => "macro call",
MacroCallKind::Derive { .. } => "derive macro",
MacroCallKind::Attr { .. } => "attribute macro",
}
}
/// Returns the file containing the macro invocation.
pub fn file_id(&self) -> HirFileId {
match *self {
MacroCallKind::FnLike { ast_id: InFile { file_id, .. }, .. }
| MacroCallKind::Derive { ast_id: InFile { file_id, .. }, .. }
| MacroCallKind::Attr { ast_id: InFile { file_id, .. }, .. } => file_id,
}
}
pub fn erased_ast_id(&self) -> ErasedFileAstId {
match *self {
MacroCallKind::FnLike { ast_id: InFile { value, .. }, .. } => value.erase(),
MacroCallKind::Derive { ast_id: InFile { value, .. }, .. } => value.erase(),
MacroCallKind::Attr { ast_id: InFile { value, .. }, .. } => value.erase(),
}
}
/// Returns the original file range that best describes the location of this macro call.
///
/// Unlike `MacroCallKind::original_call_range`, this also spans the item of attributes and derives.
pub fn original_call_range_with_body(self, db: &dyn ExpandDatabase) -> FileRange {
let mut kind = self;
let file_id = loop {
match kind.file_id().repr() {
HirFileIdRepr::MacroFile(file) => {
kind = db.lookup_intern_macro_call(file.macro_call_id).kind;
}
HirFileIdRepr::FileId(file_id) => break file_id,
}
};
let range = match kind {
MacroCallKind::FnLike { ast_id, .. } => ast_id.to_ptr(db).text_range(),
MacroCallKind::Derive { ast_id, .. } => ast_id.to_ptr(db).text_range(),
MacroCallKind::Attr { ast_id, .. } => ast_id.to_ptr(db).text_range(),
};
FileRange { range, file_id }
}
/// Returns the original file range that best describes the location of this macro call.
///
/// Here we try to roughly match what rustc does to improve diagnostics: fn-like macros
/// get the whole `ast::MacroCall`, attribute macros get the attribute's range, and derives
/// get only the specific derive that is being referred to.
pub fn original_call_range(self, db: &dyn ExpandDatabase) -> FileRange {
let mut kind = self;
let file_id = loop {
match kind.file_id().repr() {
HirFileIdRepr::MacroFile(file) => {
kind = db.lookup_intern_macro_call(file.macro_call_id).kind;
}
HirFileIdRepr::FileId(file_id) => break file_id,
}
};
let range = match kind {
MacroCallKind::FnLike { ast_id, .. } => ast_id.to_ptr(db).text_range(),
MacroCallKind::Derive { ast_id, derive_attr_index, .. } => {
// FIXME: should be the range of the macro name, not the whole derive
// FIXME: handle `cfg_attr`
collect_attrs(&ast_id.to_node(db))
.nth(derive_attr_index.ast_index())
.expect("missing derive")
.1
.expect_left("derive is a doc comment?")
.syntax()
.text_range()
}
// FIXME: handle `cfg_attr`
MacroCallKind::Attr { ast_id, invoc_attr_index, .. } => {
collect_attrs(&ast_id.to_node(db))
.nth(invoc_attr_index.ast_index())
.expect("missing attribute")
.1
.expect_left("attribute macro is a doc comment?")
.syntax()
.text_range()
}
};
FileRange { range, file_id }
}
fn arg(&self, db: &dyn ExpandDatabase) -> InFile<Option<SyntaxNode>> {
match self {
MacroCallKind::FnLike { ast_id, .. } => {
ast_id.to_in_file_node(db).map(|it| Some(it.token_tree()?.syntax().clone()))
}
MacroCallKind::Derive { ast_id, .. } => {
ast_id.to_in_file_node(db).syntax().cloned().map(Some)
}
MacroCallKind::Attr { ast_id, .. } => {
ast_id.to_in_file_node(db).syntax().cloned().map(Some)
}
}
}
}
/// ExpansionInfo mainly describes how to map text range between src and expanded macro
// FIXME: can be expensive to create, we should check the use sites and maybe replace them with
// simpler function calls if the map is only used once
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ExpansionInfo {
pub expanded: InMacroFile<SyntaxNode>,
/// The argument TokenTree or item for attributes
arg: InFile<Option<SyntaxNode>>,
/// The `macro_rules!` or attribute input.
attr_input_or_mac_def: Option<InFile<ast::TokenTree>>,
macro_def: TokenExpander,
macro_arg: Arc<tt::Subtree>,
pub exp_map: Arc<ExpansionSpanMap>,
arg_map: SpanMap,
}
impl ExpansionInfo {
pub fn expanded(&self) -> InMacroFile<SyntaxNode> {
self.expanded.clone()
}
pub fn call_node(&self) -> Option<InFile<SyntaxNode>> {
Some(self.arg.with_value(self.arg.value.as_ref()?.parent()?))
}
/// Maps the passed in file range down into a macro expansion if it is the input to a macro call.
pub fn map_range_down(
&self,
span: Span,
) -> Option<InMacroFile<impl Iterator<Item = SyntaxToken> + '_>> {
let tokens = self
.exp_map
.ranges_with_span(span)
.flat_map(move |range| self.expanded.value.covering_element(range).into_token());
Some(InMacroFile::new(self.expanded.file_id, tokens))
}
/// Looks up the span at the given offset.
pub fn span_for_offset(
&self,
db: &dyn ExpandDatabase,
offset: TextSize,
) -> (FileRange, SyntaxContextId) {
debug_assert!(self.expanded.value.text_range().contains(offset));
let span = self.exp_map.span_at(offset);
let anchor_offset = db
.ast_id_map(span.anchor.file_id.into())
.get_erased(span.anchor.ast_id)
.text_range()
.start();
(FileRange { file_id: span.anchor.file_id, range: span.range + anchor_offset }, span.ctx)
}
/// Maps up the text range out of the expansion hierarchy back into the original file its from.
pub fn map_node_range_up(
&self,
db: &dyn ExpandDatabase,
range: TextRange,
) -> Option<(FileRange, SyntaxContextId)> {
debug_assert!(self.expanded.value.text_range().contains_range(range));
let mut spans = self.exp_map.spans_for_range(range);
let Span { range, anchor, ctx } = spans.next()?;
let mut start = range.start();
let mut end = range.end();
for span in spans {
if span.anchor != anchor || span.ctx != ctx {
return None;
}
start = start.min(span.range.start());
end = end.max(span.range.end());
}
let anchor_offset =
db.ast_id_map(anchor.file_id.into()).get_erased(anchor.ast_id).text_range().start();
Some((
FileRange {
file_id: anchor.file_id,
range: TextRange::new(start, end) + anchor_offset,
},
ctx,
))
}
/// Maps up the text range out of the expansion into is macro call.
pub fn map_range_up_once(
&self,
db: &dyn ExpandDatabase,
token: TextRange,
) -> InFile<smallvec::SmallVec<[TextRange; 1]>> {
debug_assert!(self.expanded.value.text_range().contains_range(token));
let span = self.exp_map.span_at(token.start());
match &self.arg_map {
SpanMap::RealSpanMap(_) => {
let file_id = span.anchor.file_id.into();
let anchor_offset =
db.ast_id_map(file_id).get_erased(span.anchor.ast_id).text_range().start();
InFile { file_id, value: smallvec::smallvec![span.range + anchor_offset] }
}
SpanMap::ExpansionSpanMap(arg_map) => {
let arg_range = self
.arg
.value
.as_ref()
.map_or_else(|| TextRange::empty(TextSize::from(0)), |it| it.text_range());
InFile::new(
self.arg.file_id,
arg_map
.ranges_with_span(span)
.filter(|range| range.intersect(arg_range).is_some())
.collect(),
)
}
}
}
pub fn new(db: &dyn ExpandDatabase, macro_file: MacroFileId) -> ExpansionInfo {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
let arg_tt = loc.kind.arg(db);
let arg_map = db.span_map(arg_tt.file_id);
let macro_def = db.macro_expander(loc.def);
let (parse, exp_map) = db.parse_macro_expansion(macro_file).value;
let expanded = InMacroFile { file_id: macro_file, value: parse.syntax_node() };
let (macro_arg, _) = db.macro_arg(macro_file.macro_call_id).value.unwrap_or_else(|| {
(
Arc::new(tt::Subtree {
delimiter: tt::Delimiter::invisible_spanned(loc.call_site),
token_trees: Vec::new(),
}),
SyntaxFixupUndoInfo::NONE,
)
});
let def = loc.def.ast_id().left().and_then(|id| {
let def_tt = match id.to_node(db) {
ast::Macro::MacroRules(mac) => mac.token_tree()?,
ast::Macro::MacroDef(_) if matches!(macro_def, TokenExpander::BuiltInAttr(_)) => {
return None
}
ast::Macro::MacroDef(mac) => mac.body()?,
};
Some(InFile::new(id.file_id, def_tt))
});
let attr_input_or_mac_def = def.or_else(|| match loc.kind {
MacroCallKind::Attr { ast_id, invoc_attr_index, .. } => {
// FIXME: handle `cfg_attr`
let tt = collect_attrs(&ast_id.to_node(db))
.nth(invoc_attr_index.ast_index())
.and_then(|x| Either::left(x.1))?
.token_tree()?;
Some(InFile::new(ast_id.file_id, tt))
}
_ => None,
});
ExpansionInfo {
expanded,
arg: arg_tt,
attr_input_or_mac_def,
macro_arg,
macro_def,
exp_map,
arg_map,
}
}
}
/// In Rust, macros expand token trees to token trees. When we want to turn a
/// token tree into an AST node, we need to figure out what kind of AST node we
/// want: something like `foo` can be a type, an expression, or a pattern.
///
/// Naively, one would think that "what this expands to" is a property of a
/// particular macro: macro `m1` returns an item, while macro `m2` returns an
/// expression, etc. That's not the case -- macros are polymorphic in the
/// result, and can expand to any type of the AST node.
///
/// What defines the actual AST node is the syntactic context of the macro
/// invocation. As a contrived example, in `let T![*] = T![*];` the first `T`
/// expands to a pattern, while the second one expands to an expression.
///
/// `ExpandTo` captures this bit of information about a particular macro call
/// site.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum ExpandTo {
Statements,
Items,
Pattern,
Type,
Expr,
}
impl ExpandTo {
pub fn from_call_site(call: &ast::MacroCall) -> ExpandTo {
use syntax::SyntaxKind::*;
let syn = call.syntax();
let parent = match syn.parent() {
Some(it) => it,
None => return ExpandTo::Statements,
};
// FIXME: macros in statement position are treated as expression statements, they should
// probably be their own statement kind. The *grand*parent indicates what's valid.
if parent.kind() == MACRO_EXPR
&& parent
.parent()
.map_or(false, |p| matches!(p.kind(), EXPR_STMT | STMT_LIST | MACRO_STMTS))
{
return ExpandTo::Statements;
}
match parent.kind() {
MACRO_ITEMS | SOURCE_FILE | ITEM_LIST => ExpandTo::Items,
MACRO_STMTS | EXPR_STMT | STMT_LIST => ExpandTo::Statements,
MACRO_PAT => ExpandTo::Pattern,
MACRO_TYPE => ExpandTo::Type,
ARG_LIST | ARRAY_EXPR | AWAIT_EXPR | BIN_EXPR | BREAK_EXPR | CALL_EXPR | CAST_EXPR
| CLOSURE_EXPR | FIELD_EXPR | FOR_EXPR | IF_EXPR | INDEX_EXPR | LET_EXPR
| MATCH_ARM | MATCH_EXPR | MATCH_GUARD | METHOD_CALL_EXPR | PAREN_EXPR | PATH_EXPR
| PREFIX_EXPR | RANGE_EXPR | RECORD_EXPR_FIELD | REF_EXPR | RETURN_EXPR | TRY_EXPR
| TUPLE_EXPR | WHILE_EXPR | MACRO_EXPR => ExpandTo::Expr,
_ => {
// Unknown , Just guess it is `Items`
ExpandTo::Items
}
}
}
}
intern::impl_internable!(ModPath, attrs::AttrInput);