1 //! Defines database & queries for macro expansion.
5 use base_db::{salsa, SourceDatabase};
6 use mbe::{ExpandError, ExpandResult, MacroDef, MacroRules};
7 use parser::FragmentKind;
10 ast::{MacroStmts, NameOwner},
11 AstNode, GreenNode, Parse,
17 ast_id_map::AstIdMap, hygiene::HygieneFrame, BuiltinDeriveExpander, BuiltinFnLikeExpander,
18 EagerCallLoc, EagerMacroId, HirFileId, HirFileIdRepr, LazyMacroId, MacroCallId, MacroCallLoc,
19 MacroDefId, MacroDefKind, MacroFile, ProcMacroExpander,
22 /// Total limit on the number of tokens produced by any macro invocation.
24 /// If an invocation produces more tokens than this limit, it will not be stored in the database and
25 /// an error will be emitted.
26 const TOKEN_LIMIT: usize = 524288;
28 #[derive(Debug, Clone, Eq, PartialEq)]
29 pub enum TokenExpander {
30 MacroRules(mbe::MacroRules),
31 MacroDef(mbe::MacroDef),
32 Builtin(BuiltinFnLikeExpander),
33 BuiltinDerive(BuiltinDeriveExpander),
34 ProcMacro(ProcMacroExpander),
43 ) -> mbe::ExpandResult<tt::Subtree> {
45 TokenExpander::MacroRules(it) => it.expand(tt),
46 TokenExpander::MacroDef(it) => it.expand(tt),
47 TokenExpander::Builtin(it) => it.expand(db, id, tt),
48 // FIXME switch these to ExpandResult as well
49 TokenExpander::BuiltinDerive(it) => it.expand(db, id, tt).into(),
50 TokenExpander::ProcMacro(_) => {
51 // We store the result in salsa db to prevent non-deterministic behavior in
52 // some proc-macro implementation
53 // See #4315 for details
54 db.expand_proc_macro(id.into()).into()
59 pub fn map_id_down(&self, id: tt::TokenId) -> tt::TokenId {
61 TokenExpander::MacroRules(it) => it.map_id_down(id),
62 TokenExpander::MacroDef(it) => it.map_id_down(id),
63 TokenExpander::Builtin(..) => id,
64 TokenExpander::BuiltinDerive(..) => id,
65 TokenExpander::ProcMacro(..) => id,
69 pub fn map_id_up(&self, id: tt::TokenId) -> (tt::TokenId, mbe::Origin) {
71 TokenExpander::MacroRules(it) => it.map_id_up(id),
72 TokenExpander::MacroDef(it) => it.map_id_up(id),
73 TokenExpander::Builtin(..) => (id, mbe::Origin::Call),
74 TokenExpander::BuiltinDerive(..) => (id, mbe::Origin::Call),
75 TokenExpander::ProcMacro(..) => (id, mbe::Origin::Call),
80 // FIXME: rename to ExpandDatabase
81 #[salsa::query_group(AstDatabaseStorage)]
82 pub trait AstDatabase: SourceDatabase {
83 fn ast_id_map(&self, file_id: HirFileId) -> Arc<AstIdMap>;
86 fn parse_or_expand(&self, file_id: HirFileId) -> Option<SyntaxNode>;
89 fn intern_macro(&self, macro_call: MacroCallLoc) -> LazyMacroId;
90 fn macro_arg_text(&self, id: MacroCallId) -> Option<GreenNode>;
92 fn macro_arg(&self, id: MacroCallId) -> Option<Arc<(tt::Subtree, mbe::TokenMap)>>;
93 fn macro_def(&self, id: MacroDefId) -> Option<Arc<(TokenExpander, mbe::TokenMap)>>;
94 fn parse_macro_expansion(
96 macro_file: MacroFile,
97 ) -> ExpandResult<Option<(Parse<SyntaxNode>, Arc<mbe::TokenMap>)>>;
98 fn macro_expand(&self, macro_call: MacroCallId) -> ExpandResult<Option<Arc<tt::Subtree>>>;
100 /// Firewall query that returns the error from the `macro_expand` query.
101 fn macro_expand_error(&self, macro_call: MacroCallId) -> Option<ExpandError>;
104 fn intern_eager_expansion(&self, eager: EagerCallLoc) -> EagerMacroId;
106 fn expand_proc_macro(&self, call: MacroCallId) -> Result<tt::Subtree, mbe::ExpandError>;
108 fn hygiene_frame(&self, file_id: HirFileId) -> Arc<HygieneFrame>;
111 /// This expands the given macro call, but with different arguments. This is
112 /// used for completion, where we want to see what 'would happen' if we insert a
113 /// token. The `token_to_map` mapped down into the expansion, with the mapped
115 pub fn expand_hypothetical(
116 db: &dyn AstDatabase,
117 actual_macro_call: MacroCallId,
118 hypothetical_args: &syntax::ast::TokenTree,
119 token_to_map: syntax::SyntaxToken,
120 ) -> Option<(SyntaxNode, syntax::SyntaxToken)> {
121 let macro_file = MacroFile { macro_call_id: actual_macro_call };
122 let (tt, tmap_1) = mbe::syntax_node_to_token_tree(hypothetical_args.syntax()).unwrap();
124 token_to_map.text_range().checked_sub(hypothetical_args.syntax().text_range().start())?;
125 let token_id = tmap_1.token_by_range(range)?;
126 let macro_def = expander(db, actual_macro_call)?;
128 parse_macro_with_arg(db, macro_file, Some(std::sync::Arc::new((tt, tmap_1)))).value?;
129 let token_id = macro_def.0.map_id_down(token_id);
130 let range = tmap_2.range_by_token(token_id)?.by_kind(token_to_map.kind())?;
131 let token = node.syntax_node().covering_element(range).into_token()?;
132 Some((node.syntax_node(), token))
135 fn ast_id_map(db: &dyn AstDatabase, file_id: HirFileId) -> Arc<AstIdMap> {
137 db.parse_or_expand(file_id).map_or_else(AstIdMap::default, |it| AstIdMap::from_source(&it));
141 fn macro_def(db: &dyn AstDatabase, id: MacroDefId) -> Option<Arc<(TokenExpander, mbe::TokenMap)>> {
143 MacroDefKind::Declarative(ast_id) => match ast_id.to_node(db) {
144 syntax::ast::Macro::MacroRules(macro_rules) => {
145 let arg = macro_rules.token_tree()?;
146 let (tt, tmap) = mbe::ast_to_token_tree(&arg).or_else(|| {
147 log::warn!("fail on macro_rules to token tree: {:#?}", arg);
150 let rules = match MacroRules::parse(&tt) {
153 let name = macro_rules.name().map(|n| n.to_string()).unwrap_or_default();
154 log::warn!("fail on macro_def parse ({}): {:?} {:#?}", name, err, tt);
158 Some(Arc::new((TokenExpander::MacroRules(rules), tmap)))
160 syntax::ast::Macro::MacroDef(macro_def) => {
161 let arg = macro_def.body()?;
162 let (tt, tmap) = mbe::ast_to_token_tree(&arg).or_else(|| {
163 log::warn!("fail on macro_def to token tree: {:#?}", arg);
166 let rules = match MacroDef::parse(&tt) {
169 let name = macro_def.name().map(|n| n.to_string()).unwrap_or_default();
170 log::warn!("fail on macro_def parse ({}): {:?} {:#?}", name, err, tt);
174 Some(Arc::new((TokenExpander::MacroDef(rules), tmap)))
177 MacroDefKind::BuiltIn(expander, _) => {
178 Some(Arc::new((TokenExpander::Builtin(expander), mbe::TokenMap::default())))
180 MacroDefKind::BuiltInDerive(expander, _) => {
181 Some(Arc::new((TokenExpander::BuiltinDerive(expander), mbe::TokenMap::default())))
183 MacroDefKind::BuiltInEager(..) => None,
184 MacroDefKind::ProcMacro(expander, ..) => {
185 Some(Arc::new((TokenExpander::ProcMacro(expander), mbe::TokenMap::default())))
190 fn macro_arg_text(db: &dyn AstDatabase, id: MacroCallId) -> Option<GreenNode> {
192 MacroCallId::LazyMacro(id) => id,
193 MacroCallId::EagerMacro(_id) => {
194 // FIXME: support macro_arg for eager macro
198 let loc = db.lookup_intern_macro(id);
199 let arg = loc.kind.arg(db)?;
203 fn macro_arg(db: &dyn AstDatabase, id: MacroCallId) -> Option<Arc<(tt::Subtree, mbe::TokenMap)>> {
204 let arg = db.macro_arg_text(id)?;
205 let (tt, tmap) = mbe::syntax_node_to_token_tree(&SyntaxNode::new_root(arg))?;
206 Some(Arc::new((tt, tmap)))
209 fn macro_expand(db: &dyn AstDatabase, id: MacroCallId) -> ExpandResult<Option<Arc<tt::Subtree>>> {
210 macro_expand_with_arg(db, id, None)
213 fn macro_expand_error(db: &dyn AstDatabase, macro_call: MacroCallId) -> Option<ExpandError> {
214 db.macro_expand(macro_call).err
217 fn expander(db: &dyn AstDatabase, id: MacroCallId) -> Option<Arc<(TokenExpander, mbe::TokenMap)>> {
218 let lazy_id = match id {
219 MacroCallId::LazyMacro(id) => id,
220 MacroCallId::EagerMacro(_id) => {
225 let loc = db.lookup_intern_macro(lazy_id);
226 let macro_rules = db.macro_def(loc.def)?;
230 fn macro_expand_with_arg(
231 db: &dyn AstDatabase,
233 arg: Option<Arc<(tt::Subtree, mbe::TokenMap)>>,
234 ) -> ExpandResult<Option<Arc<tt::Subtree>>> {
235 let _p = profile::span("macro_expand");
236 let lazy_id = match id {
237 MacroCallId::LazyMacro(id) => id,
238 MacroCallId::EagerMacro(id) => {
240 return ExpandResult::str_err(
241 "hypothetical macro expansion not implemented for eager macro".to_owned(),
244 return ExpandResult {
245 value: Some(db.lookup_intern_eager_expansion(id).subtree),
246 // FIXME: There could be errors here!
253 let loc = db.lookup_intern_macro(lazy_id);
254 let macro_arg = match arg.or_else(|| db.macro_arg(id)) {
256 None => return ExpandResult::str_err("Fail to args in to tt::TokenTree".into()),
259 let macro_rules = match db.macro_def(loc.def) {
261 None => return ExpandResult::str_err("Fail to find macro definition".into()),
263 let ExpandResult { value: tt, err } = macro_rules.0.expand(db, lazy_id, ¯o_arg.0);
264 // Set a hard limit for the expanded tt
265 let count = tt.count();
266 if count > TOKEN_LIMIT {
267 return ExpandResult::str_err(format!(
268 "macro invocation exceeds token limit: produced {} tokens, limit is {}",
273 ExpandResult { value: Some(Arc::new(tt)), err }
276 fn expand_proc_macro(
277 db: &dyn AstDatabase,
279 ) -> Result<tt::Subtree, mbe::ExpandError> {
280 let lazy_id = match id {
281 MacroCallId::LazyMacro(id) => id,
282 MacroCallId::EagerMacro(_) => unreachable!(),
285 let loc = db.lookup_intern_macro(lazy_id);
286 let macro_arg = match db.macro_arg(id) {
290 tt::ExpansionError::Unknown("No arguments for proc-macro".to_string()).into()
295 let expander = match loc.def.kind {
296 MacroDefKind::ProcMacro(expander, ..) => expander,
300 expander.expand(db, loc.krate, ¯o_arg.0)
303 fn parse_or_expand(db: &dyn AstDatabase, file_id: HirFileId) -> Option<SyntaxNode> {
305 HirFileIdRepr::FileId(file_id) => Some(db.parse(file_id).tree().syntax().clone()),
306 HirFileIdRepr::MacroFile(macro_file) => {
307 db.parse_macro_expansion(macro_file).value.map(|(it, _)| it.syntax_node())
312 fn parse_macro_expansion(
313 db: &dyn AstDatabase,
314 macro_file: MacroFile,
315 ) -> ExpandResult<Option<(Parse<SyntaxNode>, Arc<mbe::TokenMap>)>> {
316 parse_macro_with_arg(db, macro_file, None)
319 fn parse_macro_with_arg(
320 db: &dyn AstDatabase,
321 macro_file: MacroFile,
322 arg: Option<Arc<(tt::Subtree, mbe::TokenMap)>>,
323 ) -> ExpandResult<Option<(Parse<SyntaxNode>, Arc<mbe::TokenMap>)>> {
324 let macro_call_id = macro_file.macro_call_id;
325 let result = if let Some(arg) = arg {
326 macro_expand_with_arg(db, macro_call_id, Some(arg))
328 db.macro_expand(macro_call_id)
331 let _p = profile::span("parse_macro_expansion");
333 if let Some(err) = &result.err {
335 // The final goal we would like to make all parse_macro success,
336 // such that the following log will not call anyway.
337 match macro_call_id {
338 MacroCallId::LazyMacro(id) => {
339 let loc: MacroCallLoc = db.lookup_intern_macro(id);
340 let node = loc.kind.node(db);
342 // collect parent information for warning log
343 let parents = std::iter::successors(loc.kind.file_id().call_node(db), |it| {
344 it.file_id.call_node(db)
346 .map(|n| format!("{:#}", n.value))
351 "fail on macro_parse: (reason: {:?} macro_call: {:#}) parents: {}",
358 log::warn!("fail on macro_parse: (reason: {:?})", err);
362 let tt = match result.value {
364 None => return ExpandResult { value: None, err: result.err },
367 let fragment_kind = to_fragment_kind(db, macro_call_id);
369 log::debug!("expanded = {}", tt.as_debug_string());
370 log::debug!("kind = {:?}", fragment_kind);
372 let (parse, rev_token_map) = match mbe::token_tree_to_syntax_node(&tt, fragment_kind) {
376 "failed to parse expanstion to {:?} = {}",
380 return ExpandResult::only_err(err);
386 // Safety check for recursive identity macro.
387 let node = parse.syntax_node();
388 let file: HirFileId = macro_file.into();
389 let call_node = match file.call_node(db) {
392 return ExpandResult::only_err(err);
395 if is_self_replicating(&node, &call_node.value) {
396 return ExpandResult::only_err(err);
398 ExpandResult { value: Some((parse, Arc::new(rev_token_map))), err: Some(err) }
402 log::debug!("parse = {:?}", parse.syntax_node().kind());
403 ExpandResult { value: Some((parse, Arc::new(rev_token_map))), err: None }
408 fn is_self_replicating(from: &SyntaxNode, to: &SyntaxNode) -> bool {
409 if diff(from, to).is_empty() {
412 if let Some(stmts) = MacroStmts::cast(from.clone()) {
413 if stmts.statements().any(|stmt| diff(stmt.syntax(), to).is_empty()) {
416 if let Some(expr) = stmts.expr() {
417 if diff(expr.syntax(), to).is_empty() {
425 fn hygiene_frame(db: &dyn AstDatabase, file_id: HirFileId) -> Arc<HygieneFrame> {
426 Arc::new(HygieneFrame::new(db, file_id))
429 /// Given a `MacroCallId`, return what `FragmentKind` it belongs to.
430 /// FIXME: Not completed
431 fn to_fragment_kind(db: &dyn AstDatabase, id: MacroCallId) -> FragmentKind {
432 let lazy_id = match id {
433 MacroCallId::LazyMacro(id) => id,
434 MacroCallId::EagerMacro(id) => {
435 return db.lookup_intern_eager_expansion(id).fragment;
438 let syn = db.lookup_intern_macro(lazy_id).kind.node(db).value;
440 let parent = match syn.parent() {
442 None => return FragmentKind::Statements,
445 match parent.kind() {
446 MACRO_ITEMS | SOURCE_FILE => FragmentKind::Items,
447 MACRO_STMTS => FragmentKind::Statements,
448 ITEM_LIST => FragmentKind::Items,
450 // FIXME: Handle LHS Pattern
453 EXPR_STMT => FragmentKind::Statements,
454 BLOCK_EXPR => FragmentKind::Statements,
455 ARG_LIST => FragmentKind::Expr,
456 TRY_EXPR => FragmentKind::Expr,
457 TUPLE_EXPR => FragmentKind::Expr,
458 PAREN_EXPR => FragmentKind::Expr,
459 ARRAY_EXPR => FragmentKind::Expr,
460 FOR_EXPR => FragmentKind::Expr,
461 PATH_EXPR => FragmentKind::Expr,
462 CLOSURE_EXPR => FragmentKind::Expr,
463 CONDITION => FragmentKind::Expr,
464 BREAK_EXPR => FragmentKind::Expr,
465 RETURN_EXPR => FragmentKind::Expr,
466 MATCH_EXPR => FragmentKind::Expr,
467 MATCH_ARM => FragmentKind::Expr,
468 MATCH_GUARD => FragmentKind::Expr,
469 RECORD_EXPR_FIELD => FragmentKind::Expr,
470 CALL_EXPR => FragmentKind::Expr,
471 INDEX_EXPR => FragmentKind::Expr,
472 METHOD_CALL_EXPR => FragmentKind::Expr,
473 FIELD_EXPR => FragmentKind::Expr,
474 AWAIT_EXPR => FragmentKind::Expr,
475 CAST_EXPR => FragmentKind::Expr,
476 REF_EXPR => FragmentKind::Expr,
477 PREFIX_EXPR => FragmentKind::Expr,
478 RANGE_EXPR => FragmentKind::Expr,
479 BIN_EXPR => FragmentKind::Expr,
481 // Unknown , Just guess it is `Items`