feat: add opt-in code completion for mcpp.toml

package.json

@@ -24,6 +24,7 @@
     "workspaceContains:mcpp.toml",
     "onLanguage:cpp",
     "onLanguage:mcpp-build",
+    "onLanguage:mcpp-toml",
     "onCommand:mcpp.configureClangd",
     "onCommand:mcpp.refreshCompilationDatabase",
     "onCommand:mcpp.checkModuleSupport",
@@ -146,6 +147,12 @@
           "default": true,
           "scope": "resource",
           "description": "配置 clangd 时，是否询问关闭 Microsoft C/C++ IntelliSense。"
+        },
+        "mcpp.tomlCompletion": {
+          "type": "boolean",
+          "default": false,
+          "scope": "resource",
+          "description": "为 mcpp.toml 提供代码补全：段头、各段字段、枚举/布尔取值，以及依赖与 feature 的写法模板。默认关闭。注意：该功能尚不完善，字段表可能与最新 mcpp 不同步或存在缺陷，仅供参考。"
         }
       }
     },

src/extension.ts

@@ -45,6 +45,7 @@ import {
 } from "./workflow";
 import { classifyTaskExit, type TaskCompletion } from "./tasks";
 import { MCPP_MANIFEST_GLOB, registerInProjectContext } from "./inProject";
+import { computeMcppTomlCompletions } from "./mcppTomlCompletion";
 
 const COMMAND_CONFIGURE = "mcpp.configureClangd";
 const COMMAND_REFRESH = "mcpp.refreshCompilationDatabase";
@@ -852,6 +853,49 @@ async function autoConfigureModulesWizard(
   appendOutputLine(output, `[一键配置] 一键配置完成。clangd：${resolvedClangd.path}`);
 }
 
+// mcpp.toml 的补全建议由纯函数 computeMcppTomlCompletions 计算，这里只做 vscode 类型映射。
+const mcppTomlCompletionKinds = {
+  section: vscode.CompletionItemKind.Folder,
+  key: vscode.CompletionItemKind.Field,
+  value: vscode.CompletionItemKind.EnumMember,
+  template: vscode.CompletionItemKind.Snippet,
+} as const;
+
+const mcppTomlCompletionProvider: vscode.CompletionItemProvider = {
+  provideCompletionItems(document, position) {
+    // mcpp.toml 补全默认关闭（mcpp.tomlCompletion），按文档作用域读取。
+    if (!vscode.workspace.getConfiguration("mcpp", document.uri).get<boolean>("tomlCompletion", false)) {
+      return undefined;
+    }
+    const lines: string[] = [];
+    for (let line = 0; line <= position.line; line += 1) {
+      lines.push(document.lineAt(line).text);
+    }
+    const textBefore = lines[position.line].slice(0, position.character);
+    return computeMcppTomlCompletions(lines, position.line, position.character).map((suggestion) => {
+      const item = new vscode.CompletionItem(
+        suggestion.label,
+        mcppTomlCompletionKinds[suggestion.kind],
+      );
+      item.detail = suggestion.detail;
+      if (suggestion.documentation !== undefined) {
+        item.documentation = new vscode.MarkdownString(suggestion.documentation);
+      }
+      if (suggestion.insertSnippet !== undefined) {
+        item.insertText = new vscode.SnippetString(suggestion.insertSnippet);
+      }
+      if (suggestion.kind === "section") {
+        // 段头建议要覆盖已输入的 "[xxx"，否则默认词范围会留下多余的 "["。
+        const bracket = textBefore.lastIndexOf("[");
+        if (bracket >= 0) {
+          item.range = new vscode.Range(position.line, bracket, position.line, position.character);
+        }
+      }
+      return item;
+    });
+  },
+};
+
 export async function activate(extensionContext: vscode.ExtensionContext): Promise<void> {
   moduleStatusByProject.clear();
   moduleCheckOperations.clear();
@@ -1028,6 +1072,13 @@ export async function activate(extensionContext: vscode.ExtensionContext): Promi
     output,
     status,
     ...cliController.register(),
+    vscode.languages.registerCompletionItemProvider(
+      { language: "mcpp-toml" },
+      mcppTomlCompletionProvider,
+      "[",
+      "=",
+      '"',
+    ),
     vscode.commands.registerCommand(COMMAND_CONFIGURE, runGuarded(async () => {
       const project = findCurrentProject();
       if (project === undefined) {