From 6d6cb25cf46a2327d6cb2278385763abfa7a95a0 Mon Sep 17 00:00:00 2001 From: Ryan Cumming Date: Tue, 25 Jun 2019 07:40:06 +1000 Subject: Rich mapping of cargo watch output Currently we depend on the ASCII rendering string that `rustc` provides to populate Visual Studio Code's diagnostic. This has a number of shortcomings: 1. It's not a very good use of space in the error list 2. We can't jump to secondary spans (e.g. where a called function is defined) 3. We can't use Code Actions aka Quick Fix This moves all of the low-level parsing and mapping to a `rust_diagnostics.ts`. This uses some heuristics to map Rust diagnostics to VsCode: 1. As before, the Rust diagnostic message and primary span is used for the root diagnostic. However, we now just use the message instead of the rendered version. 2. Every secondary span is converted to "related information". This shows as child in the error list and can be jumped to. 3. Every child diagnostic is categorised in to three buckets: 1. If they have no span they're treated as another line of the root messages 2. If they have replacement text they're treated as a Code Action 3. If they have a span but no replacement text they're treated as related information (same as secondary spans). --- editors/code/src/utils/rust_diagnostics.ts | 220 +++++++++++++++++++++++++++++ 1 file changed, 220 insertions(+) create mode 100644 editors/code/src/utils/rust_diagnostics.ts (limited to 'editors/code/src/utils') diff --git a/editors/code/src/utils/rust_diagnostics.ts b/editors/code/src/utils/rust_diagnostics.ts new file mode 100644 index 000000000..7d8cc0e0b --- /dev/null +++ b/editors/code/src/utils/rust_diagnostics.ts @@ -0,0 +1,220 @@ +import * as path from 'path'; +import * as vscode from 'vscode'; + +// Reference: +// https://github.com/rust-lang/rust/blob/master/src/libsyntax/json.rs +export interface RustDiagnosticSpan { + line_start: number; + line_end: number; + column_start: number; + column_end: number; + is_primary: boolean; + file_name: string; + label?: string; + suggested_replacement?: string; + suggestion_applicability?: + | 'MachineApplicable' + | 'HasPlaceholders' + | 'MaybeIncorrect' + | 'Unspecified'; +} + +export interface RustDiagnostic { + spans: RustDiagnosticSpan[]; + rendered: string; + message: string; + level: string; + code?: { + code: string; + }; + children: RustDiagnostic[]; +} + +export interface MappedRustDiagnostic { + location: vscode.Location; + diagnostic: vscode.Diagnostic; + codeActions: vscode.CodeAction[]; +} + +interface MappedRustChildDiagnostic { + related?: vscode.DiagnosticRelatedInformation; + codeAction?: vscode.CodeAction; + messageLine?: string; +} + +/** + * Converts a Rust level string to a VsCode severity + */ +function mapLevelToSeverity(s: string): vscode.DiagnosticSeverity { + if (s === 'error') { + return vscode.DiagnosticSeverity.Error; + } + if (s.startsWith('warn')) { + return vscode.DiagnosticSeverity.Warning; + } + return vscode.DiagnosticSeverity.Information; +} + +/** + * Converts a Rust span to a VsCode location + */ +function mapSpanToLocation(span: RustDiagnosticSpan): vscode.Location { + const fileName = path.join(vscode.workspace.rootPath!, span.file_name); + const fileUri = vscode.Uri.file(fileName); + + const range = new vscode.Range( + new vscode.Position(span.line_start - 1, span.column_start - 1), + new vscode.Position(span.line_end - 1, span.column_end - 1) + ); + + return new vscode.Location(fileUri, range); +} + +/** + * Converts a secondary Rust span to a VsCode related information + * + * If the span is unlabelled this will return `undefined`. + */ +function mapSecondarySpanToRelated( + span: RustDiagnosticSpan +): vscode.DiagnosticRelatedInformation | undefined { + if (!span.label) { + // Nothing to label this with + return; + } + + const location = mapSpanToLocation(span); + return new vscode.DiagnosticRelatedInformation(location, span.label); +} + +/** + * Determines if diagnostic is related to unused code + */ +function isUnusedOrUnnecessary(rd: RustDiagnostic): boolean { + if (!rd.code) { + return false; + } + + const { code } = rd.code; + return code.startsWith('unused_') || code === 'dead_code'; +} + +/** + * Converts a Rust child diagnostic to a VsCode related information + * + * This can have three outcomes: + * + * 1. If this is no primary span this will return a `noteLine` + * 2. If there is a primary span with a suggested replacement it will return a + * `codeAction`. + * 3. If there is a primary span without a suggested replacement it will return + * a `related`. + */ +function mapRustChildDiagnostic(rd: RustDiagnostic): MappedRustChildDiagnostic { + const span = rd.spans.find(s => s.is_primary); + + if (!span) { + // `rustc` uses these spanless children as a way to print multi-line + // messages + return { messageLine: rd.message }; + } + + // If we have a primary span use its location, otherwise use the parent + const location = mapSpanToLocation(span); + + // We need to distinguish `null` from an empty string + if (span && typeof span.suggested_replacement === 'string') { + const edit = new vscode.WorkspaceEdit(); + edit.replace(location.uri, location.range, span.suggested_replacement); + + // Include our replacement in the label unless it's empty + const title = span.suggested_replacement + ? `${rd.message}: \`${span.suggested_replacement}\`` + : rd.message; + + const codeAction = new vscode.CodeAction( + title, + vscode.CodeActionKind.QuickFix + ); + + codeAction.edit = edit; + codeAction.isPreferred = + span.suggestion_applicability === 'MachineApplicable'; + + return { codeAction }; + } else { + const related = new vscode.DiagnosticRelatedInformation( + location, + rd.message + ); + + return { related }; + } +} + +/** + * Converts a Rust root diagnostic to VsCode form + * + * This flattens the Rust diagnostic by: + * + * 1. Creating a `vscode.Diagnostic` with the root message and primary span. + * 2. Adding any labelled secondary spans to `relatedInformation` + * 3. Categorising child diagnostics as either Quick Fix actions, + * `relatedInformation` or additional message lines. + * + * If the diagnostic has no primary span this will return `undefined` + */ +export function mapRustDiagnosticToVsCode( + rd: RustDiagnostic +): MappedRustDiagnostic | undefined { + const codeActions = []; + + const primarySpan = rd.spans.find(s => s.is_primary); + if (!primarySpan) { + return; + } + + const location = mapSpanToLocation(primarySpan); + const secondarySpans = rd.spans.filter(s => !s.is_primary); + + const severity = mapLevelToSeverity(rd.level); + + const vd = new vscode.Diagnostic(location.range, rd.message, severity); + + vd.source = 'rustc'; + vd.code = rd.code ? rd.code.code : undefined; + vd.relatedInformation = []; + + for (const secondarySpan of secondarySpans) { + const related = mapSecondarySpanToRelated(secondarySpan); + if (related) { + vd.relatedInformation.push(related); + } + } + + for (const child of rd.children) { + const { related, codeAction, messageLine } = mapRustChildDiagnostic( + child + ); + + if (related) { + vd.relatedInformation.push(related); + } + if (codeAction) { + codeActions.push(codeAction); + } + if (messageLine) { + vd.message += `\n${messageLine}`; + } + } + + if (isUnusedOrUnnecessary(rd)) { + vd.tags = [vscode.DiagnosticTag.Unnecessary]; + } + + return { + location, + diagnostic: vd, + codeActions + }; +} -- cgit v1.2.3