rust/crates/hir-expand/src/lib.rs
Laurențiu Nicola cff7ab1308 Fix typos
2022-11-07 12:54:12 +02:00

1025 lines
40 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, semicolon_in_expressions_from_macros)]
pub mod db;
pub mod ast_id_map;
pub mod name;
pub mod hygiene;
pub mod builtin_attr_macro;
pub mod builtin_derive_macro;
pub mod builtin_fn_macro;
pub mod proc_macro;
pub mod quote;
pub mod eager;
pub mod mod_path;
mod fixup;
pub use mbe::{Origin, ValueResult};
use std::{fmt, hash::Hash, iter, sync::Arc};
use base_db::{impl_intern_key, salsa, CrateId, FileId, FileRange, ProcMacroKind};
use either::Either;
use syntax::{
algo::{self, skip_trivia_token},
ast::{self, AstNode, HasDocComments},
Direction, SyntaxNode, SyntaxToken,
};
use crate::{
ast_id_map::FileAstId,
builtin_attr_macro::BuiltinAttrExpander,
builtin_derive_macro::BuiltinDeriveExpander,
builtin_fn_macro::{BuiltinFnLikeExpander, EagerExpander},
db::TokenExpander,
mod_path::ModPath,
proc_macro::ProcMacroExpander,
};
pub type ExpandResult<T> = ValueResult<T, ExpandError>;
#[derive(Debug, PartialEq, Eq, Clone)]
pub enum ExpandError {
UnresolvedProcMacro(CrateId),
Mbe(mbe::ExpandError),
Other(Box<str>),
}
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::Other(it) => f.write_str(it),
}
}
}
/// Input to the analyzer is a set of files, where each file is identified by
/// `FileId` and contains source code. However, another source of source code in
/// Rust are macros: each macro can be thought of as producing a "temporary
/// file". To assign an id to such a file, we use the id of the macro call that
/// produced the file. So, a `HirFileId` is either a `FileId` (source code
/// written by user), or a `MacroCallId` (source code produced by macro).
///
/// What is a `MacroCallId`? Simplifying, it's a `HirFileId` of a file
/// containing the call plus the offset of the macro call in the file. Note that
/// this is a recursive definition! However, the size_of of `HirFileId` is
/// finite (because everything bottoms out at the real `FileId`) and small
/// (`MacroCallId` uses the location interning. You can check details here:
/// <https://en.wikipedia.org/wiki/String_interning>).
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct HirFileId(HirFileIdRepr);
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
enum HirFileIdRepr {
FileId(FileId),
MacroFile(MacroFile),
}
impl From<FileId> for HirFileId {
fn from(id: FileId) -> Self {
HirFileId(HirFileIdRepr::FileId(id))
}
}
impl From<MacroFile> for HirFileId {
fn from(id: MacroFile) -> Self {
HirFileId(HirFileIdRepr::MacroFile(id))
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct MacroFile {
pub macro_call_id: MacroCallId,
}
/// `MacroCallId` identifies a particular macro invocation, like
/// `println!("Hello, {}", world)`.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct MacroCallId(salsa::InternId);
impl_intern_key!(MacroCallId);
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct MacroCallLoc {
pub def: MacroDefId,
pub(crate) krate: CrateId,
eager: Option<EagerCallInfo>,
pub kind: MacroCallKind,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct MacroDefId {
pub krate: CrateId,
pub kind: MacroDefKind,
pub local_inner: bool,
}
#[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(ProcMacroExpander, ProcMacroKind, AstId<ast::Fn>),
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
struct EagerCallInfo {
/// NOTE: This can be *either* the expansion result, *or* the argument to the eager macro!
arg_or_expansion: Arc<tt::Subtree>,
included_file: Option<FileId>,
}
#[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: u32,
/// Index of the derive macro in the derive attribute
derive_index: u32,
},
Attr {
ast_id: AstId<ast::Item>,
attr_args: Arc<(tt::Subtree, mbe::TokenMap)>,
/// 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: u32,
/// Whether this attribute is the `#[derive]` attribute.
is_derive: bool,
},
}
impl HirFileId {
/// For macro-expansion files, returns the file original source file the
/// expansion originated from.
pub fn original_file(self, db: &dyn db::AstDatabase) -> FileId {
let mut file_id = self;
loop {
match file_id.0 {
HirFileIdRepr::FileId(id) => break id,
HirFileIdRepr::MacroFile(MacroFile { macro_call_id }) => {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_call_id);
file_id = match loc.eager {
Some(EagerCallInfo { included_file: Some(file), .. }) => file.into(),
_ => loc.kind.file_id(),
};
}
}
}
}
pub fn expansion_level(self, db: &dyn db::AstDatabase) -> u32 {
let mut level = 0;
let mut curr = self;
while let HirFileIdRepr::MacroFile(macro_file) = curr.0 {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
level += 1;
curr = loc.kind.file_id();
}
level
}
/// If this is a macro call, returns the syntax node of the call.
pub fn call_node(self, db: &dyn db::AstDatabase) -> Option<InFile<SyntaxNode>> {
match self.0 {
HirFileIdRepr::FileId(_) => None,
HirFileIdRepr::MacroFile(macro_file) => {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
Some(loc.kind.to_node(db))
}
}
}
/// If this is a macro call, returns the syntax node of the very first macro call this file resides in.
pub fn original_call_node(self, db: &dyn db::AstDatabase) -> Option<(FileId, SyntaxNode)> {
let mut call = match self.0 {
HirFileIdRepr::FileId(_) => return None,
HirFileIdRepr::MacroFile(MacroFile { macro_call_id }) => {
db.lookup_intern_macro_call(macro_call_id).kind.to_node(db)
}
};
loop {
match call.file_id.0 {
HirFileIdRepr::FileId(file_id) => break Some((file_id, call.value)),
HirFileIdRepr::MacroFile(MacroFile { macro_call_id }) => {
call = db.lookup_intern_macro_call(macro_call_id).kind.to_node(db);
}
}
}
}
/// Return expansion information if it is a macro-expansion file
pub fn expansion_info(self, db: &dyn db::AstDatabase) -> Option<ExpansionInfo> {
match self.0 {
HirFileIdRepr::FileId(_) => None,
HirFileIdRepr::MacroFile(macro_file) => {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
let arg_tt = loc.kind.arg(db)?;
let macro_def = db.macro_def(loc.def).ok()?;
let (parse, exp_map) = db.parse_macro_expansion(macro_file).value?;
let macro_arg = db.macro_arg(macro_file.macro_call_id)?;
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, .. } => {
let tt = ast_id
.to_node(db)
.doc_comments_and_attrs()
.nth(invoc_attr_index as usize)
.and_then(Either::left)?
.token_tree()?;
Some(InFile::new(ast_id.file_id, tt))
}
_ => None,
});
Some(ExpansionInfo {
expanded: InFile::new(self, parse.syntax_node()),
arg: InFile::new(loc.kind.file_id(), arg_tt),
attr_input_or_mac_def,
macro_arg_shift: mbe::Shift::new(&macro_arg.0),
macro_arg,
macro_def,
exp_map,
})
}
}
}
/// Indicate it is macro file generated for builtin derive
pub fn is_builtin_derive(&self, db: &dyn db::AstDatabase) -> Option<InFile<ast::Attr>> {
match self.0 {
HirFileIdRepr::FileId(_) => None,
HirFileIdRepr::MacroFile(macro_file) => {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
let attr = match loc.def.kind {
MacroDefKind::BuiltInDerive(..) => loc.kind.to_node(db),
_ => return None,
};
Some(attr.with_value(ast::Attr::cast(attr.value.clone())?))
}
}
}
pub fn is_custom_derive(&self, db: &dyn db::AstDatabase) -> bool {
match self.0 {
HirFileIdRepr::FileId(_) => false,
HirFileIdRepr::MacroFile(macro_file) => {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
matches!(loc.def.kind, MacroDefKind::ProcMacro(_, ProcMacroKind::CustomDerive, _))
}
}
}
/// Return whether this file is an include macro
pub fn is_include_macro(&self, db: &dyn db::AstDatabase) -> bool {
match self.0 {
HirFileIdRepr::MacroFile(macro_file) => {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
matches!(loc.eager, Some(EagerCallInfo { included_file: Some(_), .. }))
}
_ => false,
}
}
/// Return whether this file is an attr macro
pub fn is_attr_macro(&self, db: &dyn db::AstDatabase) -> bool {
match self.0 {
HirFileIdRepr::MacroFile(macro_file) => {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
matches!(loc.kind, MacroCallKind::Attr { .. })
}
_ => false,
}
}
/// Return whether this file is the pseudo expansion of the derive attribute.
/// See [`crate::builtin_attr_macro::derive_attr_expand`].
pub fn is_derive_attr_pseudo_expansion(&self, db: &dyn db::AstDatabase) -> bool {
match self.0 {
HirFileIdRepr::MacroFile(macro_file) => {
let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
matches!(loc.kind, MacroCallKind::Attr { is_derive: true, .. })
}
_ => false,
}
}
pub fn is_macro(self) -> bool {
matches!(self.0, HirFileIdRepr::MacroFile(_))
}
pub fn macro_file(self) -> Option<MacroFile> {
match self.0 {
HirFileIdRepr::FileId(_) => None,
HirFileIdRepr::MacroFile(m) => Some(m),
}
}
}
impl MacroDefId {
pub fn as_lazy_macro(
self,
db: &dyn db::AstDatabase,
krate: CrateId,
kind: MacroCallKind,
) -> MacroCallId {
db.intern_macro_call(MacroCallLoc { def: self, krate, eager: None, kind })
}
pub fn ast_id(&self) -> Either<AstId<ast::Macro>, AstId<ast::Fn>> {
let id = match self.kind {
MacroDefKind::ProcMacro(.., id) => return Either::Right(id),
MacroDefKind::Declarative(id)
| MacroDefKind::BuiltIn(_, id)
| MacroDefKind::BuiltInAttr(_, id)
| MacroDefKind::BuiltInDerive(_, id)
| MacroDefKind::BuiltInEager(_, id) => 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, _)
)
}
}
// FIXME: attribute indices do not account for `cfg_attr`, which means that we'll strip the whole
// `cfg_attr` instead of just one of the attributes it expands to
impl MacroCallKind {
/// Returns the file containing the macro invocation.
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 to_node(&self, db: &dyn db::AstDatabase) -> InFile<SyntaxNode> {
match self {
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| {
it.doc_comments_and_attrs()
.nth(*derive_attr_index as usize)
.and_then(|it| match it {
Either::Left(attr) => Some(attr.syntax().clone()),
Either::Right(_) => None,
})
.unwrap_or_else(|| it.syntax().clone())
})
}
MacroCallKind::Attr { ast_id, is_derive: true, invoc_attr_index, .. } => {
// FIXME: handle `cfg_attr`
ast_id.with_value(ast_id.to_node(db)).map(|it| {
it.doc_comments_and_attrs()
.nth(*invoc_attr_index as usize)
.and_then(|it| match it {
Either::Left(attr) => Some(attr.syntax().clone()),
Either::Right(_) => None,
})
.unwrap_or_else(|| it.syntax().clone())
})
}
MacroCallKind::Attr { ast_id, .. } => {
ast_id.with_value(ast_id.to_node(db).syntax().clone())
}
}
}
/// 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 db::AstDatabase) -> FileRange {
let mut kind = self;
let file_id = loop {
match kind.file_id().0 {
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_node(db).syntax().text_range(),
MacroCallKind::Derive { ast_id, .. } => ast_id.to_node(db).syntax().text_range(),
MacroCallKind::Attr { ast_id, .. } => ast_id.to_node(db).syntax().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 db::AstDatabase) -> FileRange {
let mut kind = self;
let file_id = loop {
match kind.file_id().0 {
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_node(db).syntax().text_range(),
MacroCallKind::Derive { ast_id, derive_attr_index, .. } => {
// FIXME: should be the range of the macro name, not the whole derive
ast_id
.to_node(db)
.doc_comments_and_attrs()
.nth(derive_attr_index as usize)
.expect("missing derive")
.expect_left("derive is a doc comment?")
.syntax()
.text_range()
}
MacroCallKind::Attr { ast_id, invoc_attr_index, .. } => ast_id
.to_node(db)
.doc_comments_and_attrs()
.nth(invoc_attr_index as usize)
.expect("missing attribute")
.expect_left("attribute macro is a doc comment?")
.syntax()
.text_range(),
};
FileRange { range, file_id }
}
fn arg(&self, db: &dyn db::AstDatabase) -> Option<SyntaxNode> {
match self {
MacroCallKind::FnLike { ast_id, .. } => {
Some(ast_id.to_node(db).token_tree()?.syntax().clone())
}
MacroCallKind::Derive { ast_id, .. } => Some(ast_id.to_node(db).syntax().clone()),
MacroCallKind::Attr { ast_id, .. } => Some(ast_id.to_node(db).syntax().clone()),
}
}
fn expand_to(&self) -> ExpandTo {
match self {
MacroCallKind::FnLike { expand_to, .. } => *expand_to,
MacroCallKind::Derive { .. } => ExpandTo::Items,
MacroCallKind::Attr { is_derive: true, .. } => ExpandTo::Statements,
MacroCallKind::Attr { .. } => ExpandTo::Items, // is this always correct?
}
}
}
impl MacroCallId {
pub fn as_file(self) -> HirFileId {
MacroFile { macro_call_id: self }.into()
}
}
/// ExpansionInfo mainly describes how to map text range between src and expanded macro
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ExpansionInfo {
expanded: InFile<SyntaxNode>,
/// The argument TokenTree or item for attributes
arg: InFile<SyntaxNode>,
/// The `macro_rules!` or attribute input.
attr_input_or_mac_def: Option<InFile<ast::TokenTree>>,
macro_def: Arc<TokenExpander>,
macro_arg: Arc<(tt::Subtree, mbe::TokenMap, fixup::SyntaxFixupUndoInfo)>,
/// A shift built from `macro_arg`'s subtree, relevant for attributes as the item is the macro arg
/// and as such we need to shift tokens if they are part of an attributes input instead of their item.
macro_arg_shift: mbe::Shift,
exp_map: Arc<mbe::TokenMap>,
}
impl ExpansionInfo {
pub fn expanded(&self) -> InFile<SyntaxNode> {
self.expanded.clone()
}
pub fn call_node(&self) -> Option<InFile<SyntaxNode>> {
Some(self.arg.with_value(self.arg.value.parent()?))
}
/// Map a token down from macro input into the macro expansion.
///
/// The inner workings of this function differ slightly depending on the type of macro we are dealing with:
/// - declarative:
/// For declarative macros, we need to accommodate for the macro definition site(which acts as a second unchanging input)
/// , as tokens can mapped in and out of it.
/// To do this we shift all ids in the expansion by the maximum id of the definition site giving us an easy
/// way to map all the tokens.
/// - attribute:
/// Attributes have two different inputs, the input tokentree in the attribute node and the item
/// the attribute is annotating. Similarly as for declarative macros we need to do a shift here
/// as well. Currently this is done by shifting the attribute input by the maximum id of the item.
/// - function-like and derives:
/// Both of these only have one simple call site input so no special handling is required here.
pub fn map_token_down(
&self,
db: &dyn db::AstDatabase,
item: Option<ast::Item>,
token: InFile<&SyntaxToken>,
) -> Option<impl Iterator<Item = InFile<SyntaxToken>> + '_> {
assert_eq!(token.file_id, self.arg.file_id);
let token_id_in_attr_input = if let Some(item) = item {
// check if we are mapping down in an attribute input
// this is a special case as attributes can have two inputs
let call_id = self.expanded.file_id.macro_file()?.macro_call_id;
let loc = db.lookup_intern_macro_call(call_id);
let token_range = token.value.text_range();
match &loc.kind {
MacroCallKind::Attr { attr_args, invoc_attr_index, is_derive, .. } => {
let attr = item
.doc_comments_and_attrs()
.nth(*invoc_attr_index as usize)
.and_then(Either::left)?;
match attr.token_tree() {
Some(token_tree)
if token_tree.syntax().text_range().contains_range(token_range) =>
{
let attr_input_start =
token_tree.left_delimiter_token()?.text_range().start();
let relative_range =
token.value.text_range().checked_sub(attr_input_start)?;
// shift by the item's tree's max id
let token_id = attr_args.1.token_by_range(relative_range)?;
let token_id = if *is_derive {
// we do not shift for `#[derive]`, as we only need to downmap the derive attribute tokens
token_id
} else {
self.macro_arg_shift.shift(token_id)
};
Some(token_id)
}
_ => None,
}
}
_ => None,
}
} else {
None
};
let token_id = match token_id_in_attr_input {
Some(token_id) => token_id,
// the token is not inside an attribute's input so do the lookup in the macro_arg as usual
None => {
let relative_range =
token.value.text_range().checked_sub(self.arg.value.text_range().start())?;
let token_id = self.macro_arg.1.token_by_range(relative_range)?;
// conditionally shift the id by a declaratives macro definition
self.macro_def.map_id_down(token_id)
}
};
let tokens = self
.exp_map
.ranges_by_token(token_id, token.value.kind())
.flat_map(move |range| self.expanded.value.covering_element(range).into_token());
Some(tokens.map(move |token| self.expanded.with_value(token)))
}
/// Map a token up out of the expansion it resides in into the arguments of the macro call of the expansion.
pub fn map_token_up(
&self,
db: &dyn db::AstDatabase,
token: InFile<&SyntaxToken>,
) -> Option<(InFile<SyntaxToken>, Origin)> {
// Fetch the id through its text range,
let token_id = self.exp_map.token_by_range(token.value.text_range())?;
// conditionally unshifting the id to accommodate for macro-rules def site
let (mut token_id, origin) = self.macro_def.map_id_up(token_id);
let call_id = self.expanded.file_id.macro_file()?.macro_call_id;
let loc = db.lookup_intern_macro_call(call_id);
// Attributes are a bit special for us, they have two inputs, the input tokentree and the annotated item.
let (token_map, tt) = match &loc.kind {
MacroCallKind::Attr { attr_args, is_derive: true, .. } => {
(&attr_args.1, self.attr_input_or_mac_def.clone()?.syntax().cloned())
}
MacroCallKind::Attr { attr_args, .. } => {
// try unshifting the the token id, if unshifting fails, the token resides in the non-item attribute input
// note that the `TokenExpander::map_id_up` earlier only unshifts for declarative macros, so we don't double unshift with this
match self.macro_arg_shift.unshift(token_id) {
Some(unshifted) => {
token_id = unshifted;
(&attr_args.1, self.attr_input_or_mac_def.clone()?.syntax().cloned())
}
None => (&self.macro_arg.1, self.arg.clone()),
}
}
_ => match origin {
mbe::Origin::Call => (&self.macro_arg.1, self.arg.clone()),
mbe::Origin::Def => match (&*self.macro_def, &self.attr_input_or_mac_def) {
(TokenExpander::DeclarativeMacro { def_site_token_map, .. }, Some(tt)) => {
(def_site_token_map, tt.syntax().cloned())
}
_ => panic!("`Origin::Def` used with non-`macro_rules!` macro"),
},
},
};
let range = token_map.first_range_by_token(token_id, token.value.kind())?;
let token =
tt.value.covering_element(range + tt.value.text_range().start()).into_token()?;
Some((tt.with_value(token), origin))
}
}
/// `AstId` points to an AST node in any file.
///
/// It is stable across reparses, and can be used as salsa key/value.
pub type AstId<N> = InFile<FileAstId<N>>;
impl<N: AstNode> AstId<N> {
pub fn to_node(&self, db: &dyn db::AstDatabase) -> N {
let root = db.parse_or_expand(self.file_id).unwrap();
db.ast_id_map(self.file_id).get(self.value).to_node(&root)
}
}
/// `InFile<T>` stores a value of `T` inside a particular file/syntax tree.
///
/// Typical usages are:
///
/// * `InFile<SyntaxNode>` -- syntax node in a file
/// * `InFile<ast::FnDef>` -- ast node in a file
/// * `InFile<TextSize>` -- offset in a file
#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash)]
pub struct InFile<T> {
pub file_id: HirFileId,
pub value: T,
}
impl<T> InFile<T> {
pub fn new(file_id: HirFileId, value: T) -> InFile<T> {
InFile { file_id, value }
}
pub fn with_value<U>(&self, value: U) -> InFile<U> {
InFile::new(self.file_id, value)
}
pub fn map<F: FnOnce(T) -> U, U>(self, f: F) -> InFile<U> {
InFile::new(self.file_id, f(self.value))
}
pub fn as_ref(&self) -> InFile<&T> {
self.with_value(&self.value)
}
pub fn file_syntax(&self, db: &dyn db::AstDatabase) -> SyntaxNode {
db.parse_or_expand(self.file_id).expect("source created from invalid file")
}
}
impl<T: Clone> InFile<&T> {
pub fn cloned(&self) -> InFile<T> {
self.with_value(self.value.clone())
}
}
impl<T> InFile<Option<T>> {
pub fn transpose(self) -> Option<InFile<T>> {
let value = self.value?;
Some(InFile::new(self.file_id, value))
}
}
impl<'a> InFile<&'a SyntaxNode> {
pub fn ancestors_with_macros(
self,
db: &dyn db::AstDatabase,
) -> impl Iterator<Item = InFile<SyntaxNode>> + Clone + '_ {
iter::successors(Some(self.cloned()), move |node| match node.value.parent() {
Some(parent) => Some(node.with_value(parent)),
None => node.file_id.call_node(db),
})
}
/// Skips the attributed item that caused the macro invocation we are climbing up
pub fn ancestors_with_macros_skip_attr_item(
self,
db: &dyn db::AstDatabase,
) -> impl Iterator<Item = InFile<SyntaxNode>> + '_ {
let succ = move |node: &InFile<SyntaxNode>| match node.value.parent() {
Some(parent) => Some(node.with_value(parent)),
None => {
let parent_node = node.file_id.call_node(db)?;
if node.file_id.is_attr_macro(db) {
// macro call was an attributed item, skip it
// FIXME: does this fail if this is a direct expansion of another macro?
parent_node.map(|node| node.parent()).transpose()
} else {
Some(parent_node)
}
}
};
iter::successors(succ(&self.cloned()), succ)
}
/// Falls back to the macro call range if the node cannot be mapped up fully.
///
/// For attributes and derives, this will point back to the attribute only.
/// For the entire item `InFile::use original_file_range_full`.
pub fn original_file_range(self, db: &dyn db::AstDatabase) -> FileRange {
match self.file_id.0 {
HirFileIdRepr::FileId(file_id) => FileRange { file_id, range: self.value.text_range() },
HirFileIdRepr::MacroFile(mac_file) => {
if let Some(res) = self.original_file_range_opt(db) {
return res;
}
// Fall back to whole macro call.
let loc = db.lookup_intern_macro_call(mac_file.macro_call_id);
loc.kind.original_call_range(db)
}
}
}
/// Attempts to map the syntax node back up its macro calls.
pub fn original_file_range_opt(self, db: &dyn db::AstDatabase) -> Option<FileRange> {
match ascend_node_border_tokens(db, self) {
Some(InFile { file_id, value: (first, last) }) => {
let original_file = file_id.original_file(db);
let range = first.text_range().cover(last.text_range());
if file_id != original_file.into() {
tracing::error!("Failed mapping up more for {:?}", range);
return None;
}
Some(FileRange { file_id: original_file, range })
}
_ if !self.file_id.is_macro() => Some(FileRange {
file_id: self.file_id.original_file(db),
range: self.value.text_range(),
}),
_ => None,
}
}
pub fn original_syntax_node(self, db: &dyn db::AstDatabase) -> Option<InFile<SyntaxNode>> {
// This kind of upmapping can only be achieved in attribute expanded files,
// as we don't have node inputs otherwise and therefore can't find an `N` node in the input
if !self.file_id.is_macro() {
return Some(self.map(Clone::clone));
} else if !self.file_id.is_attr_macro(db) {
return None;
}
if let Some(InFile { file_id, value: (first, last) }) = ascend_node_border_tokens(db, self)
{
if file_id.is_macro() {
let range = first.text_range().cover(last.text_range());
tracing::error!("Failed mapping out of macro file for {:?}", range);
return None;
}
// FIXME: This heuristic is brittle and with the right macro may select completely unrelated nodes
let anc = algo::least_common_ancestor(&first.parent()?, &last.parent()?)?;
let kind = self.value.kind();
let value = anc.ancestors().find(|it| it.kind() == kind)?;
return Some(InFile::new(file_id, value));
}
None
}
}
impl InFile<SyntaxToken> {
pub fn upmap(self, db: &dyn db::AstDatabase) -> Option<InFile<SyntaxToken>> {
let expansion = self.file_id.expansion_info(db)?;
expansion.map_token_up(db, self.as_ref()).map(|(it, _)| it)
}
/// Falls back to the macro call range if the node cannot be mapped up fully.
pub fn original_file_range(self, db: &dyn db::AstDatabase) -> FileRange {
match self.file_id.0 {
HirFileIdRepr::FileId(file_id) => FileRange { file_id, range: self.value.text_range() },
HirFileIdRepr::MacroFile(mac_file) => {
if let Some(res) = self.original_file_range_opt(db) {
return res;
}
// Fall back to whole macro call.
let loc = db.lookup_intern_macro_call(mac_file.macro_call_id);
loc.kind.original_call_range(db)
}
}
}
/// Attempts to map the syntax node back up its macro calls.
pub fn original_file_range_opt(self, db: &dyn db::AstDatabase) -> Option<FileRange> {
match self.file_id.0 {
HirFileIdRepr::FileId(file_id) => {
Some(FileRange { file_id, range: self.value.text_range() })
}
HirFileIdRepr::MacroFile(_) => {
let expansion = self.file_id.expansion_info(db)?;
let InFile { file_id, value } = ascend_call_token(db, &expansion, self)?;
let original_file = file_id.original_file(db);
if file_id != original_file.into() {
return None;
}
Some(FileRange { file_id: original_file, range: value.text_range() })
}
}
}
pub fn ancestors_with_macros(
self,
db: &dyn db::AstDatabase,
) -> impl Iterator<Item = InFile<SyntaxNode>> + '_ {
self.value.parent().into_iter().flat_map({
let file_id = self.file_id;
move |parent| InFile::new(file_id, &parent).ancestors_with_macros(db)
})
}
}
fn ascend_node_border_tokens(
db: &dyn db::AstDatabase,
InFile { file_id, value: node }: InFile<&SyntaxNode>,
) -> Option<InFile<(SyntaxToken, SyntaxToken)>> {
let expansion = file_id.expansion_info(db)?;
let first_token = |node: &SyntaxNode| skip_trivia_token(node.first_token()?, Direction::Next);
let last_token = |node: &SyntaxNode| skip_trivia_token(node.last_token()?, Direction::Prev);
let first = first_token(node)?;
let last = last_token(node)?;
let first = ascend_call_token(db, &expansion, InFile::new(file_id, first))?;
let last = ascend_call_token(db, &expansion, InFile::new(file_id, last))?;
(first.file_id == last.file_id).then(|| InFile::new(first.file_id, (first.value, last.value)))
}
fn ascend_call_token(
db: &dyn db::AstDatabase,
expansion: &ExpansionInfo,
token: InFile<SyntaxToken>,
) -> Option<InFile<SyntaxToken>> {
let mut mapping = expansion.map_token_up(db, token.as_ref())?;
while let (mapped, Origin::Call) = mapping {
match mapped.file_id.expansion_info(db) {
Some(info) => mapping = info.map_token_up(db, mapped.as_ref())?,
None => return Some(mapped),
}
}
None
}
impl<N: AstNode> InFile<N> {
pub fn descendants<T: AstNode>(self) -> impl Iterator<Item = InFile<T>> {
self.value.syntax().descendants().filter_map(T::cast).map(move |n| self.with_value(n))
}
pub fn original_ast_node(self, db: &dyn db::AstDatabase) -> Option<InFile<N>> {
// This kind of upmapping can only be achieved in attribute expanded files,
// as we don't have node inputs otherwise and therefore can't find an `N` node in the input
if !self.file_id.is_macro() {
return Some(self);
} else if !self.file_id.is_attr_macro(db) {
return None;
}
if let Some(InFile { file_id, value: (first, last) }) =
ascend_node_border_tokens(db, self.syntax())
{
if file_id.is_macro() {
let range = first.text_range().cover(last.text_range());
tracing::error!("Failed mapping out of macro file for {:?}", range);
return None;
}
// FIXME: This heuristic is brittle and with the right macro may select completely unrelated nodes
let anc = algo::least_common_ancestor(&first.parent()?, &last.parent()?)?;
let value = anc.ancestors().find_map(N::cast)?;
return Some(InFile::new(file_id, value));
}
None
}
pub fn syntax(&self) -> InFile<&SyntaxNode> {
self.with_value(self.value.syntax())
}
}
/// 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
}
}
}
}
#[derive(Debug)]
pub struct UnresolvedMacro {
pub path: ModPath,
}