Remove ccache from compile_commands.json

It confuses vscode's intellisense, causing it to not understand GNUC
syntaxes for example. The bug was reported upstream:
microsoft/vscode-cpptools#7616

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## next
 
+- Remove ccache from compile_commands.json because it cause issues with
+  Intellisense compiler detection.
+
 ## 1.8.1
 
 - Drop vscode-nls dependency, which was unused and is no longer provided by default

src/extension.ts

@@ -16,7 +16,8 @@ import {
   workspaceRelative,
   extensionConfigurationSet,
   getTargetName,
-  genEnvFile
+  genEnvFile,
+  patchCompileCommands
 } from "./utils";
 import {
   getMesonTargets,
@@ -39,6 +40,7 @@ import {
 export let extensionPath: string;
 let explorer: MesonProjectExplorer;
 let watcher: vscode.FileSystemWatcher;
+let compileCommandsWatcher: vscode.FileSystemWatcher;
 let mesonWatcher: vscode.FileSystemWatcher;
 let controller: vscode.TestController;
 
@@ -57,6 +59,7 @@ export async function activate(ctx: vscode.ExtensionContext) {
 
   explorer = new MesonProjectExplorer(ctx, root, buildDir);
   watcher = vscode.workspace.createFileSystemWatcher(`${workspaceRelative(extensionConfiguration("buildFolder"))}/build.ninja`, false, false, true);
+  compileCommandsWatcher = vscode.workspace.createFileSystemWatcher(`${workspaceRelative(extensionConfiguration("buildFolder"))}/compile_commands.json`, false, false, true);
   mesonWatcher = vscode.workspace.createFileSystemWatcher("**/meson.build", false, true, false);
   controller = vscode.tests.createTestController('meson-test-controller', 'Meson test controller');
 
@@ -67,6 +70,7 @@ export async function activate(ctx: vscode.ExtensionContext) {
   );
 
   ctx.subscriptions.push(watcher);
+  ctx.subscriptions.push(compileCommandsWatcher);
   ctx.subscriptions.push(mesonWatcher);
   ctx.subscriptions.push(controller);
 
@@ -92,6 +96,13 @@ export async function activate(ctx: vscode.ExtensionContext) {
   watcher.onDidCreate(changeHandler);
   await genEnvFile(buildDir);
 
+  let compileCommandsHandler = async () => {
+    await patchCompileCommands(buildDir);
+  };
+  compileCommandsWatcher.onDidChange(compileCommandsHandler);
+  compileCommandsWatcher.onDidCreate(compileCommandsHandler);
+  await patchCompileCommands(buildDir);
+
   ctx.subscriptions.push(
     vscode.tasks.registerTaskProvider("meson", {
       provideTasks(token) {

src/utils.ts

@@ -166,3 +166,27 @@ export async function genEnvFile(buildDir: string) {
     // Ignore errors, Meson could be too old to support --dump-format.
   }
 }
+
+export async function patchCompileCommands(buildDir: string) {
+  // Remove ccache from compile commands because they confuse Intellisense:
+  // https://github.com/microsoft/vscode-cpptools/issues/7616
+  try {
+    var filePath = path.join(buildDir, "compile_commands.json")
+    var db = JSON.parse(fs.readFileSync(filePath, "utf-8"));
+  } catch {
+    return;
+  }
+  var changed = false;
+  for (var i in db) {
+    // FIXME: This should use proper shlex.split() and shlex.join()
+    var cmd = db[i]['command'].split(" ");
+    if (cmd[0].endsWith("ccache")) {
+      cmd.shift();
+      db[i]["command"] = cmd.join(" ");
+      changed = true;
+    }
+  }
+  if (changed) {
+    fs.writeFileSync(filePath, JSON.stringify(db, null, "  "));
+  }
+}