diff options
| -rw-r--r-- | crates/hir_expand/src/lib.rs | 73 |
1 files changed, 52 insertions, 21 deletions
diff --git a/crates/hir_expand/src/lib.rs b/crates/hir_expand/src/lib.rs index 409d0cc66f7..bca380a4d6f 100644 --- a/crates/hir_expand/src/lib.rs +++ b/crates/hir_expand/src/lib.rs @@ -279,6 +279,13 @@ impl HirFileId { 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 { @@ -377,6 +384,8 @@ pub struct ExpansionInfo { macro_def: Arc<TokenExpander>, macro_arg: Arc<(tt::Subtree, mbe::TokenMap)>, + /// 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>, } @@ -390,6 +399,20 @@ impl ExpansionInfo { 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, @@ -397,12 +420,10 @@ impl ExpansionInfo { token: InFile<&SyntaxToken>, ) -> Option<impl Iterator<Item = InFile<SyntaxToken>> + '_> { assert_eq!(token.file_id, self.arg.file_id); - let token_id = if let Some(item) = item { + let token_id_in_attr_input = if let Some(item) = item { // check if we are mapping down in an attribute input - let call_id = match self.expanded.file_id.0 { - HirFileIdRepr::FileId(_) => return None, - HirFileIdRepr::MacroFile(macro_file) => macro_file.macro_call_id, - }; + // 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(); @@ -415,9 +436,12 @@ impl ExpansionInfo { { let attr_input_start = token_tree.left_delimiter_token()?.text_range().start(); - let range = token.value.text_range().checked_sub(attr_input_start)?; - let token_id = - self.macro_arg_shift.shift(attr_args.1.token_by_range(range)?); + let relative_range = + token.value.text_range().checked_sub(attr_input_start)?; + // shift by the item's tree's max id + let token_id = self + .macro_arg_shift + .shift(attr_args.1.token_by_range(relative_range)?); Some(token_id) } _ => None, @@ -429,12 +453,14 @@ impl ExpansionInfo { None }; - let token_id = match token_id { + 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 range = + 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(range)?; + 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) } }; @@ -447,28 +473,33 @@ impl ExpansionInfo { 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 = match self.expanded.file_id.0 { - HirFileIdRepr::FileId(_) => return None, - HirFileIdRepr::MacroFile(macro_file) => macro_file.macro_call_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, .. } => 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()) + MacroCallKind::Attr { attr_args: (_, arg_token_map), .. } => { + // 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; + (arg_token_map, self.attr_input_or_mac_def.clone()?.syntax().cloned()) + } + None => (&self.macro_arg.1, self.arg.clone()), } - 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) { |