//! See `CompletionContext` structure. use hir::{Local, ScopeDef, Semantics, SemanticsScope, Type}; use ide_db::base_db::{FilePosition, SourceDatabase}; use ide_db::{call_info::ActiveParameter, RootDatabase}; use syntax::{ algo::find_node_at_offset, ast, match_ast, AstNode, NodeOrToken, SyntaxKind::*, SyntaxNode, SyntaxToken, TextRange, TextSize, }; use test_utils::mark; use text_edit::Indel; use crate::{ patterns::{ fn_is_prev, for_is_prev2, 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, inside_impl_trait_block, is_in_loop_body, is_match_arm, unsafe_is_prev, }, CompletionConfig, }; /// `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, pub(super) is_irrefutable_pat_binding: 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.$0 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) inside_impl_trait_block: 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, pub(super) for_is_prev2: bool, pub(super) fn_is_prev: bool, pub(super) incomplete_let: bool, pub(super) locals: Vec<(String, Local)>, } 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 locals = vec![]; scope.process_all_names(&mut |name, scope| { if let ScopeDef::Local(local) = scope { locals.push((name.to_string(), local)); } }); let mut ctx = CompletionContext { sema, scope, db, config, position, original_token, token, 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_irrefutable_pat_binding: 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, dot_receiver_is_ambiguous_float_literal: false, is_call: false, is_pattern_call: false, is_macro_call: false, is_path_type: false, has_type_args: false, attribute_under_caret: None, mod_declaration_under_caret: None, unsafe_is_prev: false, if_is_prev: false, block_expr_parent: false, bind_pat_parent: false, ref_pat_parent: false, in_loop_body: false, has_trait_parent: false, has_impl_parent: false, inside_impl_trait_block: false, has_field_list_parent: false, trait_as_prev_sibling: false, impl_as_prev_sibling: false, is_match_arm: false, has_item_list_or_source_file_parent: false, for_is_prev2: false, fn_is_prev: false, incomplete_let: false, locals, }; 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) } /// Checks whether completions in that particular case don't make much sense. /// Examples: /// - `fn $0` -- we expect function name, it's unlikely that "hint" will be helpful. /// Exception for this case is `impl Trait for Foo`, where we would like to hint trait method names. /// - `for _ i$0` -- obviously, it'll be "in" keyword. pub(crate) fn no_completion_required(&self) -> bool { (self.fn_is_prev && !self.inside_impl_trait_block) || self.for_is_prev2 } /// 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 let kind = self.token.kind(); if kind == IDENT || kind == UNDERSCORE || 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.inside_impl_trait_block = inside_impl_trait_block(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()); self.for_is_prev2 = for_is_prev2(syntax_element.clone()); self.fn_is_prev = fn_is_prev(syntax_element.clone()); self.incomplete_let = syntax_element.ancestors().take(6).find_map(ast::LetStmt::cast).map_or(false, |it| { it.syntax().text_range().end() == syntax_element.text_range().end() }); } 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($0)` // * 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(Some(pat)) = bind_pat.syntax().ancestors().find_map(|node| { match_ast! { match node { ast::LetStmt(it) => Some(it.pat()), ast::Param(it) => Some(it.pat()), _ => None, } } }) { if pat.syntax().text_range().contains_range(bind_pat.syntax().text_range()) { self.is_pat_binding_or_const = false; self.is_irrefutable_pat_binding = true; } } } 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.tail_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> { syntax.covering_element(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() }