Disable xdebug by default to improve performance (#6119)

.ddev/config.yaml

@@ -27,3 +27,4 @@ web_environment:
 #  - UNISH_DB_URL=pgsql://db:db@db:5432?module=pgsql
   - DRUSH_OPTIONS_URI=$DDEV_PRIMARY_URL
   - EDITOR=nano
+  - DRUSH_ALLOW_XDEBUG=1

composer.json

@@ -21,7 +21,8 @@
     "security": "https://github.com/drush-ops/drush/security/advisories"
   },
   "bin": [
-    "drush"
+    "drush",
+    "drush.php"
   ],
   "repositories": {
     "drupal_org": {

docs/commands.md

@@ -151,3 +151,11 @@ With this configuration in place, global commands may be placed as described in
         1. The directory above `Commands` must be one of:
             1.  A Folder listed in the 'include' option. Include may be provided via [config](#global-drush-commands) or via CLI.
             1.  ../drush, /drush or /sites/all/drush. These paths are relative to Drupal root.
+
+Xdebug
+------------
+
+Drush disables Xdebug by default. This improves performance substantially, because developers are often debugging something other than Drush and they still need to clear caches, import config, etc. There are two equivalent ways to override Drush's disabling of Xdebug:
+
+- Pass the `--xdebug` global option.
+- Set an environment variable: `DRUSH_ALLOW_XDEBUG=1 drush [command]`

drush

@@ -1,4 +1,34 @@
-#!/usr/bin/env php
-<?php
+#!/usr/bin/env sh
 
-require __DIR__ . '/drush.php';
+if [ -z "$COMPOSER_RUNTIME_BIN_DIR" ]; then
+  # This branch is for the development of Drush itself.
+  # @see https://stackoverflow.com/questions/4774054
+  SCRIPTPATH="$( cd -- "$(dirname "$0")" >/dev/null 2>&1 ; pwd -P )"
+  DRUSH_PHP="$SCRIPTPATH/drush.php"
+else
+  DRUSH_PHP="$COMPOSER_RUNTIME_BIN_DIR/drush.php"
+fi
+
+parse_commandline()
+{
+	while test $# -gt 0
+	do
+		_key="$1"
+		case "$_key" in
+			--xdebug)
+				DRUSH_ALLOW_XDEBUG=1
+				return
+				;;
+		esac
+		shift
+	done
+}
+
+parse_commandline "$@"
+
+if [ "$DRUSH_ALLOW_XDEBUG" != 1 ]
+then
+  export XDEBUG_MODE=off
+fi
+
+"$DRUSH_PHP" "$@"

drush.php

@@ -1,3 +1,4 @@
+#!/usr/bin/env php
 <?php
 
 use Drush\Drush;

src/Application.php

@@ -88,6 +88,11 @@ public function configureGlobalOptions()
             ->addOption(
                 new InputOption('--define', '-D', InputOption::VALUE_REQUIRED | InputOption::VALUE_IS_ARRAY, 'Define a configuration item value.', [])
             );
+
+        $this->getDefinition()
+            ->addOption(
+                new InputOption('--xdebug', null, InputOption::VALUE_NONE, 'Drush turns off Xdebug to achieve better performance. Pass this option to keep Xdebug enabled.')
+            );
     }
 
     public function bootstrapManager()

src/Config/ConfigLocator.php

@@ -263,7 +263,13 @@ public function addSitewideConfig(string $siteRoot): ?self
         // Remember that we've seen this location.
         $this->siteRoots[] = $siteRoot;
 
-        $this->addConfigPaths(self::DRUPAL_CONTEXT, [ dirname($siteRoot) . '/drush', "$siteRoot/drush", "$siteRoot/sites/all/drush" ]);
+        $paths = [
+            dirname($siteRoot) . '/drush',
+            "$siteRoot/drush",
+            "$siteRoot/sites/all/drush",
+        ];
+        $paths = array_filter($paths, is_dir(...));
+        $this->addConfigPaths(self::DRUPAL_CONTEXT, $paths);
         return $this;
     }
 

src/Preflight/Preflight.php

@@ -255,6 +255,11 @@ public function preflight($argv): array
         // Now that we know the value, set debug flag.
         $this->logger()->setDebug($this->preflightArgs->get(PreflightArgs::DEBUG, false));
 
+        // Give hint if a developer might be trying to debug Drush.
+        if (extension_loaded('xdebug')) {
+            $this->logger()->log(strtr('Drush disables Xdebug by default. To override this, see !url', ['!url' => 'https://www.drush.org/latest/commands/#xdebug']));
+        }
+
         // Do legacy initialization (load static includes, define old constants, etc.)
         $this->init();
 

tests/functional/SqlSyncTest.php

@@ -53,14 +53,14 @@ public function testSimulatedSqlSync()
         $this->drush(SqlSyncCommands::SYNC, ['@synctest.remote', '@synctest.local'], $options, '@synctest.local');
         $output = $this->getSimplifiedErrorOutput();
         $this->assertStringContainsString("[notice] Simulating: ssh -o PasswordAuthentication=whatever [email protected] '/path/to/drush sql:dump --no-interaction --strict=0 --gzip --result-file=auto --format=json --uri=remote", $output);
-        $this->assertStringContainsString("[notice] Simulating: __DIR__/drush core:rsync @synctest.remote:/simulated/path/to/dump.tgz @synctest.local:__SANDBOX__/tmp/dump.tgz --yes --uri=local -- --remove-source-files", $output);
-        $this->assertStringContainsString("[notice] Simulating: __DIR__/drush sql:query --no-interaction --strict=0 --file=__SANDBOX__/tmp/dump.tgz --file-delete --uri=local", $output);
+        $this->assertStringContainsString("[notice] Simulating: __DIR__/drush.php core:rsync @synctest.remote:/simulated/path/to/dump.tgz @synctest.local:__SANDBOX__/tmp/dump.tgz --yes --uri=local -- --remove-source-files", $output);
+        $this->assertStringContainsString("[notice] Simulating: __DIR__/drush.php sql:query --no-interaction --strict=0 --file=__SANDBOX__/tmp/dump.tgz --file-delete --uri=local", $output);
 
         // Test simulated simple sql:sync local-to-remote
         $this->drush(SqlSyncCommands::SYNC, ['@synctest.local', '@synctest.remote'], $options, '@synctest.local');
         $output = $this->getSimplifiedErrorOutput();
-        $this->assertStringContainsString("[notice] Simulating: __DIR__/drush sql:dump --no-interaction --strict=0 --gzip --result-file=auto --format=json --uri=local", $output);
-        $this->assertStringContainsString("[notice] Simulating: __DIR__/drush core:rsync @synctest.local:/simulated/path/to/dump.tgz @synctest.remote:/tmp/dump.tgz --yes --uri=local -- --remove-source-files", $output);
+        $this->assertStringContainsString("[notice] Simulating: __DIR__/drush.php sql:dump --no-interaction --strict=0 --gzip --result-file=auto --format=json --uri=local", $output);
+        $this->assertStringContainsString("[notice] Simulating: __DIR__/drush.php core:rsync @synctest.local:/simulated/path/to/dump.tgz @synctest.remote:/tmp/dump.tgz --yes --uri=local -- --remove-source-files", $output);
         $this->assertStringContainsString("[notice] Simulating: ssh -o PasswordAuthentication=whatever [email protected] '/path/to/drush sql:query --no-interaction --strict=0 --file=/tmp/dump.tgz --file-delete --uri=remote'", $output);
 
         // Test simulated remote invoke with a remote runner.