| //! FIXME: write short doc here |
| |
| use base_db::SourceDatabase; |
| use hir::{Semantics, SemanticsScope, Type}; |
| use ide_db::RootDatabase; |
| use syntax::{ |
| algo::{find_covering_element, find_node_at_offset}, |
| ast, match_ast, AstNode, NodeOrToken, |
| SyntaxKind::*, |
| SyntaxNode, SyntaxToken, TextRange, TextSize, |
| }; |
| use test_utils::mark; |
| use text_edit::Indel; |
| |
| use crate::{ |
| call_info::ActiveParameter, |
| completion::{ |
| patterns::{ |
| has_bind_pat_parent, has_block_expr_parent, has_field_list_parent, |
| has_impl_as_prev_sibling, has_impl_parent, has_item_list_or_source_file_parent, |
| has_ref_parent, has_trait_as_prev_sibling, has_trait_parent, if_is_prev, |
| is_in_loop_body, is_match_arm, unsafe_is_prev, |
| }, |
| CompletionConfig, |
| }, |
| FilePosition, |
| }; |
| |
| /// `CompletionContext` is created early during completion to figure out, where |
| /// exactly is the cursor, syntax-wise. |
| #[derive(Debug)] |
| pub(crate) struct CompletionContext<'a> { |
| pub(super) sema: Semantics<'a, RootDatabase>, |
| pub(super) scope: SemanticsScope<'a>, |
| pub(super) db: &'a RootDatabase, |
| pub(super) config: &'a CompletionConfig, |
| pub(super) position: FilePosition, |
| /// The token before the cursor, in the original file. |
| pub(super) original_token: SyntaxToken, |
| /// The token before the cursor, in the macro-expanded file. |
| pub(super) token: SyntaxToken, |
| pub(super) krate: Option<hir::Crate>, |
| pub(super) expected_type: Option<Type>, |
| pub(super) name_ref_syntax: Option<ast::NameRef>, |
| pub(super) function_syntax: Option<ast::Fn>, |
| pub(super) use_item_syntax: Option<ast::Use>, |
| pub(super) record_lit_syntax: Option<ast::RecordExpr>, |
| pub(super) record_pat_syntax: Option<ast::RecordPat>, |
| pub(super) record_field_syntax: Option<ast::RecordExprField>, |
| pub(super) impl_def: Option<ast::Impl>, |
| /// FIXME: `ActiveParameter` is string-based, which is very very wrong |
| pub(super) active_parameter: Option<ActiveParameter>, |
| pub(super) is_param: bool, |
| /// If a name-binding or reference to a const in a pattern. |
| /// Irrefutable patterns (like let) are excluded. |
| pub(super) is_pat_binding_or_const: bool, |
| /// A single-indent path, like `foo`. `::foo` should not be considered a trivial path. |
| pub(super) is_trivial_path: bool, |
| /// If not a trivial path, the prefix (qualifier). |
| pub(super) path_qual: Option<ast::Path>, |
| pub(super) after_if: bool, |
| /// `true` if we are a statement or a last expr in the block. |
| pub(super) can_be_stmt: bool, |
| /// `true` if we expect an expression at the cursor position. |
| pub(super) is_expr: bool, |
| /// Something is typed at the "top" level, in module or impl/trait. |
| pub(super) is_new_item: bool, |
| /// The receiver if this is a field or method access, i.e. writing something.<|> |
| pub(super) dot_receiver: Option<ast::Expr>, |
| pub(super) dot_receiver_is_ambiguous_float_literal: bool, |
| /// If this is a call (method or function) in particular, i.e. the () are already there. |
| pub(super) is_call: bool, |
| /// Like `is_call`, but for tuple patterns. |
| pub(super) is_pattern_call: bool, |
| /// If this is a macro call, i.e. the () are already there. |
| pub(super) is_macro_call: bool, |
| pub(super) is_path_type: bool, |
| pub(super) has_type_args: bool, |
| pub(super) attribute_under_caret: Option<ast::Attr>, |
| pub(super) mod_declaration_under_caret: Option<ast::Module>, |
| pub(super) unsafe_is_prev: bool, |
| pub(super) if_is_prev: bool, |
| pub(super) block_expr_parent: bool, |
| pub(super) bind_pat_parent: bool, |
| pub(super) ref_pat_parent: bool, |
| pub(super) in_loop_body: bool, |
| pub(super) has_trait_parent: bool, |
| pub(super) has_impl_parent: bool, |
| pub(super) has_field_list_parent: bool, |
| pub(super) trait_as_prev_sibling: bool, |
| pub(super) impl_as_prev_sibling: bool, |
| pub(super) is_match_arm: bool, |
| pub(super) has_item_list_or_source_file_parent: bool, |
| } |
| |
| impl<'a> CompletionContext<'a> { |
| pub(super) fn new( |
| db: &'a RootDatabase, |
| position: FilePosition, |
| config: &'a CompletionConfig, |
| ) -> Option<CompletionContext<'a>> { |
| let sema = Semantics::new(db); |
| |
| let original_file = sema.parse(position.file_id); |
| |
| // Insert a fake ident to get a valid parse tree. We will use this file |
| // to determine context, though the original_file will be used for |
| // actual completion. |
| let file_with_fake_ident = { |
| let parse = db.parse(position.file_id); |
| let edit = Indel::insert(position.offset, "intellijRulezz".to_string()); |
| parse.reparse(&edit).tree() |
| }; |
| let fake_ident_token = |
| file_with_fake_ident.syntax().token_at_offset(position.offset).right_biased().unwrap(); |
| |
| let krate = sema.to_module_def(position.file_id).map(|m| m.krate()); |
| let original_token = |
| original_file.syntax().token_at_offset(position.offset).left_biased()?; |
| let token = sema.descend_into_macros(original_token.clone()); |
| let scope = sema.scope_at_offset(&token.parent(), position.offset); |
| let mut ctx = CompletionContext { |
| sema, |
| scope, |
| db, |
| config, |
| original_token, |
| token, |
| position, |
| krate, |
| expected_type: None, |
| name_ref_syntax: None, |
| function_syntax: None, |
| use_item_syntax: None, |
| record_lit_syntax: None, |
| record_pat_syntax: None, |
| record_field_syntax: None, |
| impl_def: None, |
| active_parameter: ActiveParameter::at(db, position), |
| is_param: false, |
| is_pat_binding_or_const: false, |
| is_trivial_path: false, |
| path_qual: None, |
| after_if: false, |
| can_be_stmt: false, |
| is_expr: false, |
| is_new_item: false, |
| dot_receiver: None, |
| is_call: false, |
| is_pattern_call: false, |
| is_macro_call: false, |
| is_path_type: false, |
| has_type_args: false, |
| dot_receiver_is_ambiguous_float_literal: false, |
| attribute_under_caret: None, |
| mod_declaration_under_caret: None, |
| unsafe_is_prev: false, |
| in_loop_body: false, |
| ref_pat_parent: false, |
| bind_pat_parent: false, |
| block_expr_parent: false, |
| has_trait_parent: false, |
| has_impl_parent: false, |
| has_field_list_parent: false, |
| trait_as_prev_sibling: false, |
| impl_as_prev_sibling: false, |
| if_is_prev: false, |
| is_match_arm: false, |
| has_item_list_or_source_file_parent: false, |
| }; |
| |
| let mut original_file = original_file.syntax().clone(); |
| let mut hypothetical_file = file_with_fake_ident.syntax().clone(); |
| let mut offset = position.offset; |
| let mut fake_ident_token = fake_ident_token; |
| |
| // Are we inside a macro call? |
| while let (Some(actual_macro_call), Some(macro_call_with_fake_ident)) = ( |
| find_node_at_offset::<ast::MacroCall>(&original_file, offset), |
| find_node_at_offset::<ast::MacroCall>(&hypothetical_file, offset), |
| ) { |
| if actual_macro_call.path().as_ref().map(|s| s.syntax().text()) |
| != macro_call_with_fake_ident.path().as_ref().map(|s| s.syntax().text()) |
| { |
| break; |
| } |
| let hypothetical_args = match macro_call_with_fake_ident.token_tree() { |
| Some(tt) => tt, |
| None => break, |
| }; |
| if let (Some(actual_expansion), Some(hypothetical_expansion)) = ( |
| ctx.sema.expand(&actual_macro_call), |
| ctx.sema.speculative_expand( |
| &actual_macro_call, |
| &hypothetical_args, |
| fake_ident_token, |
| ), |
| ) { |
| let new_offset = hypothetical_expansion.1.text_range().start(); |
| if new_offset > actual_expansion.text_range().end() { |
| break; |
| } |
| original_file = actual_expansion; |
| hypothetical_file = hypothetical_expansion.0; |
| fake_ident_token = hypothetical_expansion.1; |
| offset = new_offset; |
| } else { |
| break; |
| } |
| } |
| ctx.fill_keyword_patterns(&hypothetical_file, offset); |
| ctx.fill(&original_file, hypothetical_file, offset); |
| Some(ctx) |
| } |
| |
| // The range of the identifier that is being completed. |
| pub(crate) fn source_range(&self) -> TextRange { |
| // check kind of macro-expanded token, but use range of original token |
| if self.token.kind() == IDENT || self.token.kind().is_keyword() { |
| mark::hit!(completes_if_prefix_is_keyword); |
| self.original_token.text_range() |
| } else { |
| TextRange::empty(self.position.offset) |
| } |
| } |
| |
| fn fill_keyword_patterns(&mut self, file_with_fake_ident: &SyntaxNode, offset: TextSize) { |
| let fake_ident_token = file_with_fake_ident.token_at_offset(offset).right_biased().unwrap(); |
| let syntax_element = NodeOrToken::Token(fake_ident_token); |
| self.block_expr_parent = has_block_expr_parent(syntax_element.clone()); |
| self.unsafe_is_prev = unsafe_is_prev(syntax_element.clone()); |
| self.if_is_prev = if_is_prev(syntax_element.clone()); |
| self.bind_pat_parent = has_bind_pat_parent(syntax_element.clone()); |
| self.ref_pat_parent = has_ref_parent(syntax_element.clone()); |
| self.in_loop_body = is_in_loop_body(syntax_element.clone()); |
| self.has_trait_parent = has_trait_parent(syntax_element.clone()); |
| self.has_impl_parent = has_impl_parent(syntax_element.clone()); |
| self.has_field_list_parent = has_field_list_parent(syntax_element.clone()); |
| self.impl_as_prev_sibling = has_impl_as_prev_sibling(syntax_element.clone()); |
| self.trait_as_prev_sibling = has_trait_as_prev_sibling(syntax_element.clone()); |
| self.is_match_arm = is_match_arm(syntax_element.clone()); |
| self.has_item_list_or_source_file_parent = |
| has_item_list_or_source_file_parent(syntax_element.clone()); |
| self.mod_declaration_under_caret = |
| find_node_at_offset::<ast::Module>(&file_with_fake_ident, offset) |
| .filter(|module| module.item_list().is_none()); |
| } |
| |
| fn fill( |
| &mut self, |
| original_file: &SyntaxNode, |
| file_with_fake_ident: SyntaxNode, |
| offset: TextSize, |
| ) { |
| // FIXME: this is wrong in at least two cases: |
| // * when there's no token `foo(<|>)` |
| // * when there is a token, but it happens to have type of it's own |
| self.expected_type = self |
| .token |
| .ancestors() |
| .find_map(|node| { |
| let ty = match_ast! { |
| match node { |
| ast::Pat(it) => self.sema.type_of_pat(&it), |
| ast::Expr(it) => self.sema.type_of_expr(&it), |
| _ => return None, |
| } |
| }; |
| Some(ty) |
| }) |
| .flatten(); |
| self.attribute_under_caret = find_node_at_offset(&file_with_fake_ident, offset); |
| |
| // First, let's try to complete a reference to some declaration. |
| if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(&file_with_fake_ident, offset) { |
| // Special case, `trait T { fn foo(i_am_a_name_ref) {} }`. |
| // See RFC#1685. |
| if is_node::<ast::Param>(name_ref.syntax()) { |
| self.is_param = true; |
| return; |
| } |
| // FIXME: remove this (V) duplication and make the check more precise |
| if name_ref.syntax().ancestors().find_map(ast::RecordPatFieldList::cast).is_some() { |
| self.record_pat_syntax = |
| self.sema.find_node_at_offset_with_macros(&original_file, offset); |
| } |
| self.classify_name_ref(original_file, name_ref, offset); |
| } |
| |
| // Otherwise, see if this is a declaration. We can use heuristics to |
| // suggest declaration names, see `CompletionKind::Magic`. |
| if let Some(name) = find_node_at_offset::<ast::Name>(&file_with_fake_ident, offset) { |
| if let Some(bind_pat) = name.syntax().ancestors().find_map(ast::IdentPat::cast) { |
| self.is_pat_binding_or_const = true; |
| if bind_pat.at_token().is_some() |
| || bind_pat.ref_token().is_some() |
| || bind_pat.mut_token().is_some() |
| { |
| self.is_pat_binding_or_const = false; |
| } |
| if bind_pat.syntax().parent().and_then(ast::RecordPatFieldList::cast).is_some() { |
| self.is_pat_binding_or_const = false; |
| } |
| if let Some(let_stmt) = bind_pat.syntax().ancestors().find_map(ast::LetStmt::cast) { |
| if let Some(pat) = let_stmt.pat() { |
| if pat.syntax().text_range().contains_range(bind_pat.syntax().text_range()) |
| { |
| self.is_pat_binding_or_const = false; |
| } |
| } |
| } |
| } |
| if is_node::<ast::Param>(name.syntax()) { |
| self.is_param = true; |
| return; |
| } |
| // FIXME: remove this (^) duplication and make the check more precise |
| if name.syntax().ancestors().find_map(ast::RecordPatFieldList::cast).is_some() { |
| self.record_pat_syntax = |
| self.sema.find_node_at_offset_with_macros(&original_file, offset); |
| } |
| } |
| } |
| |
| fn classify_name_ref( |
| &mut self, |
| original_file: &SyntaxNode, |
| name_ref: ast::NameRef, |
| offset: TextSize, |
| ) { |
| self.name_ref_syntax = |
| find_node_at_offset(&original_file, name_ref.syntax().text_range().start()); |
| let name_range = name_ref.syntax().text_range(); |
| if ast::RecordExprField::for_field_name(&name_ref).is_some() { |
| self.record_lit_syntax = |
| self.sema.find_node_at_offset_with_macros(&original_file, offset); |
| } |
| |
| self.impl_def = self |
| .sema |
| .ancestors_with_macros(self.token.parent()) |
| .take_while(|it| it.kind() != SOURCE_FILE && it.kind() != MODULE) |
| .find_map(ast::Impl::cast); |
| |
| let top_node = name_ref |
| .syntax() |
| .ancestors() |
| .take_while(|it| it.text_range() == name_range) |
| .last() |
| .unwrap(); |
| |
| match top_node.parent().map(|it| it.kind()) { |
| Some(SOURCE_FILE) | Some(ITEM_LIST) => { |
| self.is_new_item = true; |
| return; |
| } |
| _ => (), |
| } |
| |
| self.use_item_syntax = |
| self.sema.ancestors_with_macros(self.token.parent()).find_map(ast::Use::cast); |
| |
| self.function_syntax = self |
| .sema |
| .ancestors_with_macros(self.token.parent()) |
| .take_while(|it| it.kind() != SOURCE_FILE && it.kind() != MODULE) |
| .find_map(ast::Fn::cast); |
| |
| self.record_field_syntax = self |
| .sema |
| .ancestors_with_macros(self.token.parent()) |
| .take_while(|it| { |
| it.kind() != SOURCE_FILE && it.kind() != MODULE && it.kind() != CALL_EXPR |
| }) |
| .find_map(ast::RecordExprField::cast); |
| |
| let parent = match name_ref.syntax().parent() { |
| Some(it) => it, |
| None => return, |
| }; |
| |
| if let Some(segment) = ast::PathSegment::cast(parent.clone()) { |
| let path = segment.parent_path(); |
| self.is_call = path |
| .syntax() |
| .parent() |
| .and_then(ast::PathExpr::cast) |
| .and_then(|it| it.syntax().parent().and_then(ast::CallExpr::cast)) |
| .is_some(); |
| self.is_macro_call = path.syntax().parent().and_then(ast::MacroCall::cast).is_some(); |
| self.is_pattern_call = |
| path.syntax().parent().and_then(ast::TupleStructPat::cast).is_some(); |
| |
| self.is_path_type = path.syntax().parent().and_then(ast::PathType::cast).is_some(); |
| self.has_type_args = segment.generic_arg_list().is_some(); |
| |
| if let Some(path) = path_or_use_tree_qualifier(&path) { |
| self.path_qual = path |
| .segment() |
| .and_then(|it| { |
| find_node_with_range::<ast::PathSegment>( |
| original_file, |
| it.syntax().text_range(), |
| ) |
| }) |
| .map(|it| it.parent_path()); |
| return; |
| } |
| |
| if let Some(segment) = path.segment() { |
| if segment.coloncolon_token().is_some() { |
| return; |
| } |
| } |
| |
| self.is_trivial_path = true; |
| |
| // Find either enclosing expr statement (thing with `;`) or a |
| // block. If block, check that we are the last expr. |
| self.can_be_stmt = name_ref |
| .syntax() |
| .ancestors() |
| .find_map(|node| { |
| if let Some(stmt) = ast::ExprStmt::cast(node.clone()) { |
| return Some(stmt.syntax().text_range() == name_ref.syntax().text_range()); |
| } |
| if let Some(block) = ast::BlockExpr::cast(node) { |
| return Some( |
| block.expr().map(|e| e.syntax().text_range()) |
| == Some(name_ref.syntax().text_range()), |
| ); |
| } |
| None |
| }) |
| .unwrap_or(false); |
| self.is_expr = path.syntax().parent().and_then(ast::PathExpr::cast).is_some(); |
| |
| if let Some(off) = name_ref.syntax().text_range().start().checked_sub(2.into()) { |
| if let Some(if_expr) = |
| self.sema.find_node_at_offset_with_macros::<ast::IfExpr>(original_file, off) |
| { |
| if if_expr.syntax().text_range().end() < name_ref.syntax().text_range().start() |
| { |
| self.after_if = true; |
| } |
| } |
| } |
| } |
| if let Some(field_expr) = ast::FieldExpr::cast(parent.clone()) { |
| // The receiver comes before the point of insertion of the fake |
| // ident, so it should have the same range in the non-modified file |
| self.dot_receiver = field_expr |
| .expr() |
| .map(|e| e.syntax().text_range()) |
| .and_then(|r| find_node_with_range(original_file, r)); |
| self.dot_receiver_is_ambiguous_float_literal = |
| if let Some(ast::Expr::Literal(l)) = &self.dot_receiver { |
| match l.kind() { |
| ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'), |
| _ => false, |
| } |
| } else { |
| false |
| } |
| } |
| if let Some(method_call_expr) = ast::MethodCallExpr::cast(parent) { |
| // As above |
| self.dot_receiver = method_call_expr |
| .receiver() |
| .map(|e| e.syntax().text_range()) |
| .and_then(|r| find_node_with_range(original_file, r)); |
| self.is_call = true; |
| } |
| } |
| } |
| |
| fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> { |
| find_covering_element(syntax, range).ancestors().find_map(N::cast) |
| } |
| |
| fn is_node<N: AstNode>(node: &SyntaxNode) -> bool { |
| match node.ancestors().find_map(N::cast) { |
| None => false, |
| Some(n) => n.syntax().text_range() == node.text_range(), |
| } |
| } |
| |
| fn path_or_use_tree_qualifier(path: &ast::Path) -> Option<ast::Path> { |
| if let Some(qual) = path.qualifier() { |
| return Some(qual); |
| } |
| let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?; |
| let use_tree = use_tree_list.syntax().parent().and_then(ast::UseTree::cast)?; |
| use_tree.path() |
| } |
