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());
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);
147 let rules = match MacroRules::parse(&tt) {
150 let name = macro_rules.name().map(|n| n.to_string()).unwrap_or_default();
151 log::warn!("fail on macro_def parse ({}): {:?} {:#?}", name, err, tt);
155 Some(Arc::new((TokenExpander::MacroRules(rules), tmap)))
157 syntax::ast::Macro::MacroDef(macro_def) => {
158 let arg = macro_def.body()?;
159 let (tt, tmap) = mbe::ast_to_token_tree(&arg);
160 let rules = match MacroDef::parse(&tt) {
163 let name = macro_def.name().map(|n| n.to_string()).unwrap_or_default();
164 log::warn!("fail on macro_def parse ({}): {:?} {:#?}", name, err, tt);
168 Some(Arc::new((TokenExpander::MacroDef(rules), tmap)))
171 MacroDefKind::BuiltIn(expander, _) => {
172 Some(Arc::new((TokenExpander::Builtin(expander), mbe::TokenMap::default())))
174 MacroDefKind::BuiltInDerive(expander, _) => {
175 Some(Arc::new((TokenExpander::BuiltinDerive(expander), mbe::TokenMap::default())))
177 MacroDefKind::BuiltInEager(..) => None,
178 MacroDefKind::ProcMacro(expander, ..) => {
179 Some(Arc::new((TokenExpander::ProcMacro(expander), mbe::TokenMap::default())))
184 fn macro_arg_text(db: &dyn AstDatabase, id: MacroCallId) -> Option<GreenNode> {
186 MacroCallId::LazyMacro(id) => id,
187 MacroCallId::EagerMacro(_id) => {
188 // FIXME: support macro_arg for eager macro
192 let loc = db.lookup_intern_macro(id);
193 let arg = loc.kind.arg(db)?;
197 fn macro_arg(db: &dyn AstDatabase, id: MacroCallId) -> Option<Arc<(tt::Subtree, mbe::TokenMap)>> {
198 let arg = db.macro_arg_text(id)?;
199 let (tt, tmap) = mbe::syntax_node_to_token_tree(&SyntaxNode::new_root(arg));
200 Some(Arc::new((tt, tmap)))
203 fn macro_expand(db: &dyn AstDatabase, id: MacroCallId) -> ExpandResult<Option<Arc<tt::Subtree>>> {
204 macro_expand_with_arg(db, id, None)
207 fn macro_expand_error(db: &dyn AstDatabase, macro_call: MacroCallId) -> Option<ExpandError> {
208 db.macro_expand(macro_call).err
211 fn expander(db: &dyn AstDatabase, id: MacroCallId) -> Option<Arc<(TokenExpander, mbe::TokenMap)>> {
212 let lazy_id = match id {
213 MacroCallId::LazyMacro(id) => id,
214 MacroCallId::EagerMacro(_id) => {
219 let loc = db.lookup_intern_macro(lazy_id);
220 let macro_rules = db.macro_def(loc.def)?;
224 fn macro_expand_with_arg(
225 db: &dyn AstDatabase,
227 arg: Option<Arc<(tt::Subtree, mbe::TokenMap)>>,
228 ) -> ExpandResult<Option<Arc<tt::Subtree>>> {
229 let _p = profile::span("macro_expand");
230 let lazy_id = match id {
231 MacroCallId::LazyMacro(id) => id,
232 MacroCallId::EagerMacro(id) => {
234 return ExpandResult::str_err(
235 "hypothetical macro expansion not implemented for eager macro".to_owned(),
238 return ExpandResult {
239 value: Some(db.lookup_intern_eager_expansion(id).subtree),
240 // FIXME: There could be errors here!
247 let loc = db.lookup_intern_macro(lazy_id);
248 let macro_arg = match arg.or_else(|| db.macro_arg(id)) {
250 None => return ExpandResult::str_err("Fail to args in to tt::TokenTree".into()),
253 let macro_rules = match db.macro_def(loc.def) {
255 None => return ExpandResult::str_err("Fail to find macro definition".into()),
257 let ExpandResult { value: tt, err } = macro_rules.0.expand(db, lazy_id, ¯o_arg.0);
258 // Set a hard limit for the expanded tt
259 let count = tt.count();
260 if count > TOKEN_LIMIT {
261 return ExpandResult::str_err(format!(
262 "macro invocation exceeds token limit: produced {} tokens, limit is {}",
267 ExpandResult { value: Some(Arc::new(tt)), err }
270 fn expand_proc_macro(
271 db: &dyn AstDatabase,
273 ) -> Result<tt::Subtree, mbe::ExpandError> {
274 let lazy_id = match id {
275 MacroCallId::LazyMacro(id) => id,
276 MacroCallId::EagerMacro(_) => unreachable!(),
279 let loc = db.lookup_intern_macro(lazy_id);
280 let macro_arg = match db.macro_arg(id) {
284 tt::ExpansionError::Unknown("No arguments for proc-macro".to_string()).into()
289 let expander = match loc.def.kind {
290 MacroDefKind::ProcMacro(expander, ..) => expander,
294 expander.expand(db, loc.krate, ¯o_arg.0)
297 fn parse_or_expand(db: &dyn AstDatabase, file_id: HirFileId) -> Option<SyntaxNode> {
299 HirFileIdRepr::FileId(file_id) => Some(db.parse(file_id).tree().syntax().clone()),
300 HirFileIdRepr::MacroFile(macro_file) => {
301 db.parse_macro_expansion(macro_file).value.map(|(it, _)| it.syntax_node())
306 fn parse_macro_expansion(
307 db: &dyn AstDatabase,
308 macro_file: MacroFile,
309 ) -> ExpandResult<Option<(Parse<SyntaxNode>, Arc<mbe::TokenMap>)>> {
310 parse_macro_with_arg(db, macro_file, None)
313 fn parse_macro_with_arg(
314 db: &dyn AstDatabase,
315 macro_file: MacroFile,
316 arg: Option<Arc<(tt::Subtree, mbe::TokenMap)>>,
317 ) -> ExpandResult<Option<(Parse<SyntaxNode>, Arc<mbe::TokenMap>)>> {
318 let macro_call_id = macro_file.macro_call_id;
319 let result = if let Some(arg) = arg {
320 macro_expand_with_arg(db, macro_call_id, Some(arg))
322 db.macro_expand(macro_call_id)
325 let _p = profile::span("parse_macro_expansion");
327 if let Some(err) = &result.err {
329 // The final goal we would like to make all parse_macro success,
330 // such that the following log will not call anyway.
331 match macro_call_id {
332 MacroCallId::LazyMacro(id) => {
333 let loc: MacroCallLoc = db.lookup_intern_macro(id);
334 let node = loc.kind.node(db);
336 // collect parent information for warning log
337 let parents = std::iter::successors(loc.kind.file_id().call_node(db), |it| {
338 it.file_id.call_node(db)
340 .map(|n| format!("{:#}", n.value))
345 "fail on macro_parse: (reason: {:?} macro_call: {:#}) parents: {}",
352 log::warn!("fail on macro_parse: (reason: {:?})", err);
356 let tt = match result.value {
358 None => return ExpandResult { value: None, err: result.err },
361 let fragment_kind = to_fragment_kind(db, macro_call_id);
363 log::debug!("expanded = {}", tt.as_debug_string());
364 log::debug!("kind = {:?}", fragment_kind);
366 let (parse, rev_token_map) = match mbe::token_tree_to_syntax_node(&tt, fragment_kind) {
370 "failed to parse expanstion to {:?} = {}",
374 return ExpandResult::only_err(err);
380 // Safety check for recursive identity macro.
381 let node = parse.syntax_node();
382 let file: HirFileId = macro_file.into();
383 let call_node = match file.call_node(db) {
386 return ExpandResult::only_err(err);
389 if is_self_replicating(&node, &call_node.value) {
390 return ExpandResult::only_err(err);
392 ExpandResult { value: Some((parse, Arc::new(rev_token_map))), err: Some(err) }
396 log::debug!("parse = {:?}", parse.syntax_node().kind());
397 ExpandResult { value: Some((parse, Arc::new(rev_token_map))), err: None }
402 fn is_self_replicating(from: &SyntaxNode, to: &SyntaxNode) -> bool {
403 if diff(from, to).is_empty() {
406 if let Some(stmts) = MacroStmts::cast(from.clone()) {
407 if stmts.statements().any(|stmt| diff(stmt.syntax(), to).is_empty()) {
410 if let Some(expr) = stmts.expr() {
411 if diff(expr.syntax(), to).is_empty() {
419 fn hygiene_frame(db: &dyn AstDatabase, file_id: HirFileId) -> Arc<HygieneFrame> {
420 Arc::new(HygieneFrame::new(db, file_id))
423 /// Given a `MacroCallId`, return what `FragmentKind` it belongs to.
424 /// FIXME: Not completed
425 fn to_fragment_kind(db: &dyn AstDatabase, id: MacroCallId) -> FragmentKind {
426 let lazy_id = match id {
427 MacroCallId::LazyMacro(id) => id,
428 MacroCallId::EagerMacro(id) => {
429 return db.lookup_intern_eager_expansion(id).fragment;
432 let syn = db.lookup_intern_macro(lazy_id).kind.node(db).value;
434 let parent = match syn.parent() {
436 None => return FragmentKind::Statements,
439 match parent.kind() {
440 MACRO_ITEMS | SOURCE_FILE => FragmentKind::Items,
441 MACRO_STMTS => FragmentKind::Statements,
442 ITEM_LIST => FragmentKind::Items,
444 // FIXME: Handle LHS Pattern
447 EXPR_STMT => FragmentKind::Statements,
448 BLOCK_EXPR => FragmentKind::Statements,
449 ARG_LIST => FragmentKind::Expr,
450 TRY_EXPR => FragmentKind::Expr,
451 TUPLE_EXPR => FragmentKind::Expr,
452 PAREN_EXPR => FragmentKind::Expr,
453 ARRAY_EXPR => FragmentKind::Expr,
454 FOR_EXPR => FragmentKind::Expr,
455 PATH_EXPR => FragmentKind::Expr,
456 CLOSURE_EXPR => FragmentKind::Expr,
457 CONDITION => FragmentKind::Expr,
458 BREAK_EXPR => FragmentKind::Expr,
459 RETURN_EXPR => FragmentKind::Expr,
460 MATCH_EXPR => FragmentKind::Expr,
461 MATCH_ARM => FragmentKind::Expr,
462 MATCH_GUARD => FragmentKind::Expr,
463 RECORD_EXPR_FIELD => FragmentKind::Expr,
464 CALL_EXPR => FragmentKind::Expr,
465 INDEX_EXPR => FragmentKind::Expr,
466 METHOD_CALL_EXPR => FragmentKind::Expr,
467 FIELD_EXPR => FragmentKind::Expr,
468 AWAIT_EXPR => FragmentKind::Expr,
469 CAST_EXPR => FragmentKind::Expr,
470 REF_EXPR => FragmentKind::Expr,
471 PREFIX_EXPR => FragmentKind::Expr,
472 RANGE_EXPR => FragmentKind::Expr,
473 BIN_EXPR => FragmentKind::Expr,
475 // Unknown , Just guess it is `Items`