Defer cache directory creation until it's needed

UPGRADING.md

@@ -27,6 +27,9 @@
 
 - [BC] TPositiveInt has been removed and replaced by TIntRange
 
+- [BC] Property `Psalm\Config::$cache_directory` is now internal. Use
+  `Psalm\Config::getCacheDirectory()` instead.
+
 - [BC] The parameter `$php_version` of `Psalm\Type\Atomic::create()` renamed
   to `$analysis_php_version_id` and changed from `array|null` to `int|null`.
   Previously it accepted PHP version as `array{major_version, minor_version}`

src/Psalm/Config.php

@@ -204,10 +204,14 @@ class Config
     /**
      * The directory to store PHP Parser (and other) caches
      *
+     * @internal
+     *
      * @var string|null
      */
     public $cache_directory;
 
+    private bool $cache_directory_initialized = false;
+
     /**
      * The directory to store all Psalm project caches
      *
@@ -1094,32 +1098,6 @@ private static function fromXmlAndPaths(
 
         $config->cache_directory .= DIRECTORY_SEPARATOR . sha1($base_dir);
 
-        $cwd = null;
-
-        if ($config->resolve_from_config_file) {
-            $cwd = getcwd();
-            chdir($config->base_dir);
-        }
-
-        if (!is_dir($config->cache_directory)) {
-            try {
-                if (mkdir($config->cache_directory, 0777, true) === false) {
-                    // any other error than directory already exists/permissions issue
-                    throw new RuntimeException('Failed to create Psalm cache directory for unknown reasons');
-                }
-            } catch (RuntimeException $e) {
-                if (!is_dir($config->cache_directory)) {
-                    // rethrow the error with default message
-                    // it contains the reason why creation failed
-                    throw $e;
-                }
-            }
-        }
-
-        if ($cwd) {
-            chdir($cwd);
-        }
-
         if (isset($config_xml['serializer'])) {
             $attribute_text = (string) $config_xml['serializer'];
             $config->use_igbinary = $attribute_text === 'igbinary';
@@ -2221,6 +2199,44 @@ public function visitStubFiles(Codebase $codebase, ?Progress $progress = null):
 
     public function getCacheDirectory(): ?string
     {
+        if ($this->cache_directory === null) {
+            return null;
+        }
+
+        if ($this->cache_directory_initialized) {
+            return $this->cache_directory;
+        }
+
+        $cwd = null;
+
+        if ($this->resolve_from_config_file) {
+            $cwd = getcwd();
+            chdir($this->base_dir);
+        }
+
+        try {
+            if (!is_dir($this->cache_directory)) {
+                try {
+                    if (mkdir($this->cache_directory, 0777, true) === false) {
+                        // any other error than directory already exists/permissions issue
+                        throw new RuntimeException('Failed to create Psalm cache directory for unknown reasons');
+                    }
+                } catch (RuntimeException $e) {
+                    if (!is_dir($this->cache_directory)) {
+                        // rethrow the error with default message
+                        // it contains the reason why creation failed
+                        throw $e;
+                    }
+                }
+            }
+        } finally {
+            if ($cwd) {
+                chdir($cwd);
+            }
+        }
+
+        $this->cache_directory_initialized = true;
+
         return $this->cache_directory;
     }
 
@@ -2457,7 +2473,9 @@ public static function removeCacheDirectory(string $dir): void
 
     public function setServerMode(): void
     {
-        $this->cache_directory .= '-s';
+        if ($this->cache_directory !== null) {
+            $this->cache_directory .= '-s';
+        }
     }
 
     public function addStubFile(string $stub_file): void

src/Psalm/Internal/Cli/Psalm.php

@@ -241,6 +241,10 @@ public static function run(array $argv): void
             $options
         );
 
+        if (isset($options['no-cache'])) {
+            $config->cache_directory = null;
+        }
+
         $config->setIncludeCollector($include_collector);
 
         $in_ci = CliUtils::runningInCI();        // disable progressbar on CI

src/Psalm/Internal/Cli/Psalter.php

@@ -233,6 +233,11 @@ public static function run(array $argv): void
             Report::TYPE_CONSOLE,
             $first_autoloader
         );
+
+        if (isset($options['no-cache'])) {
+            $config->cache_directory = null;
+        }
+
         $config->setIncludeCollector($include_collector);
 
         if ($config->resolve_from_config_file) {