UNPKG

langium

Version:

A language engineering tool for the Language Server Protocol

259 lines 11.5 kB
/****************************************************************************** * Copyright 2021 TypeFox GmbH * This program and the accompanying materials are made available under the * terms of the MIT License, which is available in the project root. ******************************************************************************/ import { CancellationToken } from '../utils/cancellation.js'; import { isAstNode, isAstNodeDescription, isLinkingError } from '../syntax-tree.js'; import { findRootNode, streamAst, streamReferences } from '../utils/ast-utils.js'; import { interruptAndCheck } from '../utils/promise-utils.js'; import { DocumentState } from '../workspace/documents.js'; export const RefResolving = Symbol('RefResolving'); export class DefaultLinker { constructor(services) { this.reflection = services.shared.AstReflection; this.langiumDocuments = () => services.shared.workspace.LangiumDocuments; this.scopeProvider = services.references.ScopeProvider; this.astNodeLocator = services.workspace.AstNodeLocator; } async link(document, cancelToken = CancellationToken.None) { for (const node of streamAst(document.parseResult.value)) { await interruptAndCheck(cancelToken); streamReferences(node).forEach(ref => this.doLink(ref, document)); } } doLink(refInfo, document) { const ref = refInfo.reference; // The reference may already have been resolved lazily by accessing its `ref` property. if ('_ref' in ref && ref._ref === undefined) { ref._ref = RefResolving; try { const description = this.getCandidate(refInfo); if (isLinkingError(description)) { ref._ref = description; } else { ref._nodeDescription = description; const linkedNode = this.loadAstNode(description); ref._ref = linkedNode ?? this.createLinkingError(refInfo, description); } } catch (err) { console.error(`An error occurred while resolving reference to '${ref.$refText}':`, err); const errorMessage = err.message ?? String(err); ref._ref = { info: refInfo, message: `An error occurred while resolving reference to '${ref.$refText}': ${errorMessage}` }; } document.references.push(ref); } else if ('_items' in ref && ref._items === undefined) { ref._items = RefResolving; try { const descriptions = this.getCandidates(refInfo); const items = []; if (isLinkingError(descriptions)) { ref._linkingError = descriptions; } else { for (const description of descriptions) { const linkedNode = this.loadAstNode(description); if (linkedNode) { items.push({ ref: linkedNode, $nodeDescription: description }); } } } ref._items = items; } catch (err) { ref._linkingError = { info: refInfo, message: `An error occurred while resolving reference to '${ref.$refText}': ${err}` }; ref._items = []; } document.references.push(ref); } } unlink(document) { for (const ref of document.references) { if ('_ref' in ref) { ref._ref = undefined; delete ref._nodeDescription; } else if ('_items' in ref) { ref._items = undefined; delete ref._linkingError; } } document.references = []; } getCandidate(refInfo) { const scope = this.scopeProvider.getScope(refInfo); const description = scope.getElement(refInfo.reference.$refText); return description ?? this.createLinkingError(refInfo); } getCandidates(refInfo) { const scope = this.scopeProvider.getScope(refInfo); const descriptions = scope.getElements(refInfo.reference.$refText).distinct(desc => `${desc.documentUri}#${desc.path}`).toArray(); return descriptions.length > 0 ? descriptions : this.createLinkingError(refInfo); } buildReference(node, property, refNode, refText) { // See behavior description in doc of Linker, update that on changes in here. // eslint-disable-next-line @typescript-eslint/no-this-alias const linker = this; const reference = { $refNode: refNode, $refText: refText, _ref: undefined, get ref() { if (isAstNode(this._ref)) { // Most frequent case: the target is already resolved. return this._ref; } else if (isAstNodeDescription(this._nodeDescription)) { // A candidate has been found before, but it is not loaded yet. const linkedNode = linker.loadAstNode(this._nodeDescription); this._ref = linkedNode ?? linker.createLinkingError({ reference, container: node, property }, this._nodeDescription); } else if (this._ref === undefined) { // The reference has not been linked yet, so do that now. this._ref = RefResolving; const document = findRootNode(node).$document; const refData = linker.getLinkedNode({ reference, container: node, property }); if (refData.error && document && document.state < DocumentState.ComputedScopes) { // Document scope is not ready, don't set `this._ref` so linker can retry later. return this._ref = undefined; } this._ref = refData.node ?? refData.error; this._nodeDescription = refData.descr; document?.references.push(this); } else if (this._ref === RefResolving) { linker.throwCyclicReferenceError(node, property, refText); } return isAstNode(this._ref) ? this._ref : undefined; }, get $nodeDescription() { return this._nodeDescription; }, get error() { return isLinkingError(this._ref) ? this._ref : undefined; } }; return reference; } buildMultiReference(node, property, refNode, refText) { // See behavior description in doc of Linker, update that on changes in here. // eslint-disable-next-line @typescript-eslint/no-this-alias const linker = this; const reference = { $refNode: refNode, $refText: refText, _items: undefined, get items() { if (Array.isArray(this._items)) { return this._items; } else if (this._items === undefined) { this._items = RefResolving; const document = findRootNode(node).$document; const descriptions = linker.getCandidates({ reference, container: node, property }); const items = []; if (isLinkingError(descriptions)) { this._linkingError = descriptions; } else { for (const description of descriptions) { const linkedNode = linker.loadAstNode(description); if (linkedNode) { items.push({ ref: linkedNode, $nodeDescription: description }); } } } this._items = items; document?.references.push(this); } else if (this._items === RefResolving) { linker.throwCyclicReferenceError(node, property, refText); } return Array.isArray(this._items) ? this._items : []; }, get error() { if (this._linkingError) { return this._linkingError; } const refs = this.items; if (refs.length > 0) { return undefined; } else { return (this._linkingError = linker.createLinkingError({ reference, container: node, property })); } } }; return reference; } throwCyclicReferenceError(node, property, refText) { throw new Error(`Cyclic reference resolution detected: ${this.astNodeLocator.getAstNodePath(node)}/${property} (symbol '${refText}')`); } getLinkedNode(refInfo) { try { const description = this.getCandidate(refInfo); if (isLinkingError(description)) { return { error: description }; } const linkedNode = this.loadAstNode(description); if (linkedNode) { return { node: linkedNode, descr: description }; } else { return { descr: description, error: this.createLinkingError(refInfo, description) }; } } catch (err) { console.error(`An error occurred while resolving reference to '${refInfo.reference.$refText}':`, err); const errorMessage = err.message ?? String(err); return { error: { info: refInfo, message: `An error occurred while resolving reference to '${refInfo.reference.$refText}': ${errorMessage}` } }; } } loadAstNode(nodeDescription) { if (nodeDescription.node) { return nodeDescription.node; } const doc = this.langiumDocuments().getDocument(nodeDescription.documentUri); if (!doc) { return undefined; } return this.astNodeLocator.getAstNode(doc.parseResult.value, nodeDescription.path); } createLinkingError(refInfo, targetDescription) { // Check whether the document is sufficiently processed by the DocumentBuilder. If not, this is a hint for a bug // in the language implementation. const document = findRootNode(refInfo.container).$document; if (document && document.state < DocumentState.ComputedScopes) { console.warn(`Attempted reference resolution before document reached ComputedScopes state (${document.uri}).`); } const referenceType = this.reflection.getReferenceType(refInfo); return { info: refInfo, message: `Could not resolve reference to ${referenceType} named '${refInfo.reference.$refText}'.`, targetDescription }; } } //# sourceMappingURL=linker.js.map