Auto merge of #12215 - listochkin:Support-variable-substitution-in-vscode-settings, r=Veykril

feat: Support variable substitution in VSCode settings Currently support a subset of [variables provided by VSCode](https://code.visualstudio.com/docs/editor/variables-reference) in `server.extraEnv` section of Rust-Analyzer settings: * `workspaceFolder` * `workspaceFolderBasename` * `cwd` * `execPath` * `pathSeparator` Also, this PR adds support for general environment variables resolution. You can declare environment variables and reference them from other variables like this: ```JSON "rust-analyzer.server.extraEnv": { "RUSTFLAGS": "-L${env:OPEN_XR_SDK_PATH}", "OPEN_XR_SDK_PATH": "${workspaceFolder}\\..\\OpenXR-SDK\\build\\src\\loader\\Release" }, ``` The order of variable declaration doesn't matter, you can reference variables before defining them. If the variable is not present in `extraEnv` section, VSCode will search for them in your environment. Missing variables will be replaced with empty string. Circular references won't be resolved and will be passed to rust-analyzer server process as is. Closes #9626, but doesn't address use cases where people want to use values provided by `rustc` or `cargo`, such as `${targetTriple}` proposal #11649
2025-08-22 11:24:24 +00:00 · 2022-05-12 11:05:21 +00:00 · 2022-05-12 11:05:21 +00:00 · 927ef0ce7e
commit 927ef0ce7e
parent 7a55863c3d 33d2c8a3f9
7 changed files with 225 additions and 9 deletions
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@ -1,3 +1,4 @@
+import path = require('path');
 import * as vscode from 'vscode';
 import { Env } from './client';
 import { log } from "./util";
@ -210,3 +211,125 @@ export async function updateConfig(config: vscode.WorkspaceConfiguration) {
        }
    }
 }
+
+export function substituteVariablesInEnv(env: Env): Env {
+    const missingDeps = new Set<string>();
+    // vscode uses `env:ENV_NAME` for env vars resolution, and it's easier
+    // to follow the same convention for our dependency tracking
+    const definedEnvKeys = new Set(Object.keys(env).map(key => `env:${key}`));
+    const envWithDeps = Object.fromEntries(Object.entries(env).map(([key, value]) => {
+        const deps = new Set<string>();
+        const depRe = new RegExp(/\${(?<depName>.+?)}/g);
+        let match = undefined;
+        while ((match = depRe.exec(value))) {
+            const depName = match.groups!.depName;
+            deps.add(depName);
+            // `depName` at this point can have a form of `expression` or
+            // `prefix:expression`
+            if (!definedEnvKeys.has(depName)) {
+                missingDeps.add(depName);
+            }
+        }
+        return [`env:${key}`, { deps: [...deps], value }];
+    }));
+
+    const resolved = new Set<string>();
+    for (const dep of missingDeps) {
+        const match = /(?<prefix>.*?):(?<body>.+)/.exec(dep);
+        if (match) {
+            const { prefix, body } = match.groups!;
+            if (prefix === 'env') {
+                const envName = body;
+                envWithDeps[dep] = {
+                    value: process.env[envName] ?? '',
+                    deps: []
+                };
+                resolved.add(dep);
+            } else {
+                // we can't handle other prefixes at the moment
+                // leave values as is, but still mark them as resolved
+                envWithDeps[dep] = {
+                    value: '${' + dep + '}',
+                    deps: []
+                };
+                resolved.add(dep);
+            }
+        } else {
+            envWithDeps[dep] = {
+                value: computeVscodeVar(dep),
+                deps: []
+            };
+        }
+    }
+    const toResolve = new Set(Object.keys(envWithDeps));
+
+    let leftToResolveSize;
+    do {
+        leftToResolveSize = toResolve.size;
+        for (const key of toResolve) {
+            if (envWithDeps[key].deps.every(dep => resolved.has(dep))) {
+                envWithDeps[key].value = envWithDeps[key].value.replace(
+                    /\${(?<depName>.+?)}/g, (_wholeMatch, depName) => {
+                        return envWithDeps[depName].value;
+                    });
+                resolved.add(key);
+                toResolve.delete(key);
+            }
+        }
+    } while (toResolve.size > 0 && toResolve.size < leftToResolveSize);
+
+    const resolvedEnv: Env = {};
+    for (const key of Object.keys(env)) {
+        resolvedEnv[key] = envWithDeps[`env:${key}`].value;
+    }
+    return resolvedEnv;
+}
+
+function computeVscodeVar(varName: string): string {
+    // https://code.visualstudio.com/docs/editor/variables-reference
+    const supportedVariables: { [k: string]: () => string } = {
+        workspaceFolder: () => {
+            const folders = vscode.workspace.workspaceFolders ?? [];
+            if (folders.length === 1) {
+                // TODO: support for remote workspaces?
+                return folders[0].uri.fsPath;
+            } else if (folders.length > 1) {
+                // could use currently opened document to detect the correct
+                // workspace. However, that would be determined by the document
+                // user has opened on Editor startup. Could lead to
+                // unpredictable workspace selection in practice.
+                // It's better to pick the first one
+                return folders[0].uri.fsPath;
+            } else {
+                // no workspace opened
+                return '';
+            }
+        },
+
+        workspaceFolderBasename: () => {
+            const workspaceFolder = computeVscodeVar('workspaceFolder');
+            if (workspaceFolder) {
+                return path.basename(workspaceFolder);
+            } else {
+                return '';
+            }
+        },
+
+        cwd: () => process.cwd(),
+
+        // see
+        // https://github.com/microsoft/vscode/blob/08ac1bb67ca2459496b272d8f4a908757f24f56f/src/vs/workbench/api/common/extHostVariableResolverService.ts#L81
+        // or
+        // https://github.com/microsoft/vscode/blob/29eb316bb9f154b7870eb5204ec7f2e7cf649bec/src/vs/server/node/remoteTerminalChannel.ts#L56
+        execPath: () => process.env.VSCODE_EXEC_PATH ?? process.execPath,
+
+        pathSeparator: () => path.sep
+    };
+
+    if (varName in supportedVariables) {
+        return supportedVariables[varName]();
+    } else {
+        // can't resolve, keep the expression as is
+        return '${' + varName + '}';
+    }
+}