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+//! `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>),
+ // FIXME: maybe just Builtin and rename BuiltinFnLikeExpander to BuiltinExpander
+ 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 ususal
+ 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,
+ }
+ }
+}
+
+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 therefor 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(true, |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,
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-27 05:33:33 +0000