diff --git a/bin/functionMetadata_original.php b/bin/functionMetadata_original.php
index 838d2ecd5c..f4c9cd19fc 100644
--- a/bin/functionMetadata_original.php
+++ b/bin/functionMetadata_original.php
@@ -70,8 +70,6 @@
 	'chown' => ['hasSideEffects' => true],
 	'copy' => ['hasSideEffects' => true],
 	'count' => ['hasSideEffects' => false],
-	'connection_aborted' => ['hasSideEffects' => true],
-	'connection_status' => ['hasSideEffects' => true],
 	'error_log' => ['hasSideEffects' => true],
 	'fclose' => ['hasSideEffects' => true],
 	'fflush' => ['hasSideEffects' => true],
@@ -79,7 +77,6 @@
 	'fgetcsv' => ['hasSideEffects' => true],
 	'fgets' => ['hasSideEffects' => true],
 	'fgetss' => ['hasSideEffects' => true],
-	'file_get_contents' => ['hasSideEffects' => true],
 	'file_put_contents' => ['hasSideEffects' => true],
 	'flock' => ['hasSideEffects' => true],
 	'fopen' => ['hasSideEffects' => true],
@@ -98,6 +95,18 @@
 	'mb_str_pad' => ['hasSideEffects' => false],
 	'mkdir' => ['hasSideEffects' => true],
 	'move_uploaded_file' => ['hasSideEffects' => true],
+	'ob_clean' => ['hasSideEffects' => true],
+	'ob_end_clean' => ['hasSideEffects' => true],
+	'ob_end_flush' => ['hasSideEffects' => true],
+	'ob_flush' => ['hasSideEffects' => true],
+	'ob_get_clean' => ['hasSideEffects' => true],
+	'ob_get_contents' => ['hasSideEffects' => true],
+	'ob_get_length' => ['hasSideEffects' => true],
+	'ob_get_level' => ['hasSideEffects' => true],
+	'ob_get_status' => ['hasSideEffects' => true],
+	'ob_list_handlers' => ['hasSideEffects' => true],
+	'output_add_rewrite_var' => ['hasSideEffects' => true],
+	'output_reset_rewrite_vars' => ['hasSideEffects' => true],
 	'pclose' => ['hasSideEffects' => true],
 	'popen' => ['hasSideEffects' => true],
 	'readfile' => ['hasSideEffects' => true],
diff --git a/bin/generate-function-metadata.php b/bin/generate-function-metadata.php
index 97737499a5..80032561d9 100755
--- a/bin/generate-function-metadata.php
+++ b/bin/generate-function-metadata.php
@@ -25,18 +25,63 @@
 		/** @var string[] */
 		public array $functions = [];
 
+		/** @var list<string> */
+		public array $impureFunctions = [];
+
 		/** @var string[] */
 		public array $methods = [];
 
 		public function enterNode(Node $node)
 		{
 			if ($node instanceof Node\Stmt\Function_) {
+				assert(isset($node->namespacedName));
+				$functionName = $node->namespacedName->toLowerString();
+
 				foreach ($node->attrGroups as $attrGroup) {
 					foreach ($attrGroup->attrs as $attr) {
-						if ($attr->name->toString() === Pure::class) {
-							$this->functions[] = $node->namespacedName->toLowerString();
+						if ($attr->name->toString() !== Pure::class) {
+							continue;
+						}
+
+						// The following functions have side effects, but their state is managed within the PHPStan scope:
+						if (in_array($functionName, [
+							'stat',
+							'lstat',
+							'file_exists',
+							'is_writable',
+							'is_writeable',
+							'is_readable',
+							'is_executable',
+							'is_file',
+							'is_dir',
+							'is_link',
+							'filectime',
+							'fileatime',
+							'filemtime',
+							'fileinode',
+							'filegroup',
+							'fileowner',
+							'filesize',
+							'filetype',
+							'fileperms',
+							'ftell',
+							'ini_get',
+							'function_exists',
+							'json_last_error',
+							'json_last_error_msg',
+						], true)) {
+							$this->functions[] = $functionName;
 							break 2;
 						}
+
+						// PhpStorm stub's #[Pure(true)] means the function has side effects but its return value is important.
+						// In PHPStan's criteria, these functions are simply considered as ['hasSideEffect' => true].
+						if (isset($attr->args[0]->value->name->name) && $attr->args[0]->value->name->name === 'true') {
+							$this->impureFunctions[] = $functionName;
+						} else {
+							$this->functions[] = $functionName;
+						}
+						break 2;
 					}
 				}
 			}
@@ -74,26 +119,29 @@ public function enterNode(Node $node)
 		);
 	}
 
+	/** @var array<string, array{hasSideEffects: bool}> $metadata */
 	$metadata = require __DIR__ . '/functionMetadata_original.php';
 	foreach ($visitor->functions as $functionName) {
 		if (array_key_exists($functionName, $metadata)) {
 			if ($metadata[$functionName]['hasSideEffects']) {
-				if (in_array($functionName, [
-					'mt_rand',
-					'rand',
-					'random_bytes',
-					'random_int',
-					'connection_aborted',
-					'connection_status',
-					'file_get_contents',
-				], true)) {
-					continue;
-				}
 				throw new ShouldNotHappenException($functionName);
 			}
 		}
 		$metadata[$functionName] = ['hasSideEffects' => false];
 	}
+	foreach ($visitor->impureFunctions as $functionName) {
+		if (array_key_exists($functionName, $metadata)) {
+			if (in_array($functionName, [
+				'ob_get_contents',
+			], true)) {
+				continue;
+			}
+			if ($metadata[$functionName]['hasSideEffects']) {
+				throw new ShouldNotHappenException($functionName);
+			}
+		}
+		$metadata[$functionName] = ['hasSideEffects' => true];
+	}
 
 	foreach ($visitor->methods as $methodName) {
 		if (array_key_exists($methodName, $metadata)) {
diff --git a/resources/functionMetadata.php b/resources/functionMetadata.php
index 0c5c33759a..69cbb72a62 100644
--- a/resources/functionMetadata.php
+++ b/resources/functionMetadata.php
@@ -766,7 +766,7 @@
 	'bzerrstr' => ['hasSideEffects' => false],
 	'bzopen' => ['hasSideEffects' => false],
 	'ceil' => ['hasSideEffects' => false],
-	'checkdate' => ['hasSideEffects' => false],
+	'checkdate' => ['hasSideEffects' => true],
 	'checkdnsrr' => ['hasSideEffects' => false],
 	'chgrp' => ['hasSideEffects' => true],
 	'chmod' => ['hasSideEffects' => true],
@@ -776,11 +776,11 @@
 	'chunk_split' => ['hasSideEffects' => false],
 	'class_implements' => ['hasSideEffects' => false],
 	'class_parents' => ['hasSideEffects' => false],
-	'cli_get_process_title' => ['hasSideEffects' => false],
+	'cli_get_process_title' => ['hasSideEffects' => true],
 	'collator_compare' => ['hasSideEffects' => false],
 	'collator_create' => ['hasSideEffects' => false],
 	'collator_get_attribute' => ['hasSideEffects' => false],
-	'collator_get_error_code' => ['hasSideEffects' => false],
+	'collator_get_error_code' => ['hasSideEffects' => true],
 	'collator_get_error_message' => ['hasSideEffects' => false],
 	'collator_get_locale' => ['hasSideEffects' => false],
 	'collator_get_sort_key' => ['hasSideEffects' => false],
@@ -788,7 +788,7 @@
 	'compact' => ['hasSideEffects' => false],
 	'connection_aborted' => ['hasSideEffects' => true],
 	'connection_status' => ['hasSideEffects' => true],
-	'constant' => ['hasSideEffects' => false],
+	'constant' => ['hasSideEffects' => true],
 	'convert_cyr_string' => ['hasSideEffects' => false],
 	'convert_uudecode' => ['hasSideEffects' => false],
 	'convert_uuencode' => ['hasSideEffects' => false],
@@ -811,47 +811,47 @@
 	'ctype_upper' => ['hasSideEffects' => false],
 	'ctype_xdigit' => ['hasSideEffects' => false],
 	'curl_copy_handle' => ['hasSideEffects' => false],
-	'curl_errno' => ['hasSideEffects' => false],
-	'curl_error' => ['hasSideEffects' => false],
+	'curl_errno' => ['hasSideEffects' => true],
+	'curl_error' => ['hasSideEffects' => true],
 	'curl_escape' => ['hasSideEffects' => false],
 	'curl_file_create' => ['hasSideEffects' => false],
-	'curl_getinfo' => ['hasSideEffects' => false],
-	'curl_multi_errno' => ['hasSideEffects' => false],
+	'curl_getinfo' => ['hasSideEffects' => true],
+	'curl_multi_errno' => ['hasSideEffects' => true],
 	'curl_multi_getcontent' => ['hasSideEffects' => false],
 	'curl_multi_info_read' => ['hasSideEffects' => false],
-	'curl_share_errno' => ['hasSideEffects' => false],
+	'curl_share_errno' => ['hasSideEffects' => true],
 	'curl_share_strerror' => ['hasSideEffects' => false],
 	'curl_strerror' => ['hasSideEffects' => false],
 	'curl_unescape' => ['hasSideEffects' => false],
 	'curl_version' => ['hasSideEffects' => false],
 	'current' => ['hasSideEffects' => false],
-	'date' => ['hasSideEffects' => false],
-	'date_create' => ['hasSideEffects' => false],
-	'date_create_from_format' => ['hasSideEffects' => false],
-	'date_create_immutable' => ['hasSideEffects' => false],
-	'date_create_immutable_from_format' => ['hasSideEffects' => false],
+	'date' => ['hasSideEffects' => true],
+	'date_create' => ['hasSideEffects' => true],
+	'date_create_from_format' => ['hasSideEffects' => true],
+	'date_create_immutable' => ['hasSideEffects' => true],
+	'date_create_immutable_from_format' => ['hasSideEffects' => true],
 	'date_default_timezone_get' => ['hasSideEffects' => false],
-	'date_diff' => ['hasSideEffects' => false],
-	'date_format' => ['hasSideEffects' => false],
-	'date_get_last_errors' => ['hasSideEffects' => false],
-	'date_interval_create_from_date_string' => ['hasSideEffects' => false],
-	'date_interval_format' => ['hasSideEffects' => false],
-	'date_offset_get' => ['hasSideEffects' => false],
-	'date_parse' => ['hasSideEffects' => false],
-	'date_parse_from_format' => ['hasSideEffects' => false],
-	'date_sun_info' => ['hasSideEffects' => false],
-	'date_sunrise' => ['hasSideEffects' => false],
-	'date_sunset' => ['hasSideEffects' => false],
-	'date_timestamp_get' => ['hasSideEffects' => false],
-	'date_timezone_get' => ['hasSideEffects' => false],
+	'date_diff' => ['hasSideEffects' => true],
+	'date_format' => ['hasSideEffects' => true],
+	'date_get_last_errors' => ['hasSideEffects' => true],
+	'date_interval_create_from_date_string' => ['hasSideEffects' => true],
+	'date_interval_format' => ['hasSideEffects' => true],
+	'date_offset_get' => ['hasSideEffects' => true],
+	'date_parse' => ['hasSideEffects' => true],
+	'date_parse_from_format' => ['hasSideEffects' => true],
+	'date_sun_info' => ['hasSideEffects' => true],
+	'date_sunrise' => ['hasSideEffects' => true],
+	'date_sunset' => ['hasSideEffects' => true],
+	'date_timestamp_get' => ['hasSideEffects' => true],
+	'date_timezone_get' => ['hasSideEffects' => true],
 	'datefmt_create' => ['hasSideEffects' => false],
 	'datefmt_format' => ['hasSideEffects' => false],
 	'datefmt_format_object' => ['hasSideEffects' => false],
 	'datefmt_get_calendar' => ['hasSideEffects' => false],
 	'datefmt_get_calendar_object' => ['hasSideEffects' => false],
 	'datefmt_get_datetype' => ['hasSideEffects' => false],
-	'datefmt_get_error_code' => ['hasSideEffects' => false],
-	'datefmt_get_error_message' => ['hasSideEffects' => false],
+	'datefmt_get_error_code' => ['hasSideEffects' => true],
+	'datefmt_get_error_message' => ['hasSideEffects' => true],
 	'datefmt_get_locale' => ['hasSideEffects' => false],
 	'datefmt_get_pattern' => ['hasSideEffects' => false],
 	'datefmt_get_timetype' => ['hasSideEffects' => false],
@@ -862,16 +862,16 @@
 	'decbin' => ['hasSideEffects' => false],
 	'dechex' => ['hasSideEffects' => false],
 	'decoct' => ['hasSideEffects' => false],
-	'defined' => ['hasSideEffects' => false],
+	'defined' => ['hasSideEffects' => true],
 	'deflate_init' => ['hasSideEffects' => false],
 	'deg2rad' => ['hasSideEffects' => false],
 	'dirname' => ['hasSideEffects' => false],
-	'disk_free_space' => ['hasSideEffects' => false],
-	'disk_total_space' => ['hasSideEffects' => false],
-	'diskfreespace' => ['hasSideEffects' => false],
+	'disk_free_space' => ['hasSideEffects' => true],
+	'disk_total_space' => ['hasSideEffects' => true],
+	'diskfreespace' => ['hasSideEffects' => true],
 	'dngettext' => ['hasSideEffects' => false],
 	'doubleval' => ['hasSideEffects' => false],
-	'error_get_last' => ['hasSideEffects' => false],
+	'error_get_last' => ['hasSideEffects' => true],
 	'error_log' => ['hasSideEffects' => true],
 	'escapeshellarg' => ['hasSideEffects' => false],
 	'escapeshellcmd' => ['hasSideEffects' => false],
@@ -881,13 +881,13 @@
 	'extension_loaded' => ['hasSideEffects' => false],
 	'fclose' => ['hasSideEffects' => true],
 	'fdiv' => ['hasSideEffects' => false],
-	'feof' => ['hasSideEffects' => false],
+	'feof' => ['hasSideEffects' => true],
 	'fflush' => ['hasSideEffects' => true],
 	'fgetc' => ['hasSideEffects' => true],
 	'fgetcsv' => ['hasSideEffects' => true],
 	'fgets' => ['hasSideEffects' => true],
 	'fgetss' => ['hasSideEffects' => true],
-	'file' => ['hasSideEffects' => false],
+	'file' => ['hasSideEffects' => true],
 	'file_exists' => ['hasSideEffects' => false],
 	'file_get_contents' => ['hasSideEffects' => true],
 	'file_put_contents' => ['hasSideEffects' => true],
@@ -913,7 +913,7 @@
 	'flock' => ['hasSideEffects' => true],
 	'floor' => ['hasSideEffects' => false],
 	'fmod' => ['hasSideEffects' => false],
-	'fnmatch' => ['hasSideEffects' => false],
+	'fnmatch' => ['hasSideEffects' => true],
 	'fopen' => ['hasSideEffects' => true],
 	'fpassthru' => ['hasSideEffects' => true],
 	'fputcsv' => ['hasSideEffects' => true],
@@ -921,17 +921,17 @@
 	'fread' => ['hasSideEffects' => true],
 	'fscanf' => ['hasSideEffects' => true],
 	'fseek' => ['hasSideEffects' => true],
-	'fstat' => ['hasSideEffects' => false],
+	'fstat' => ['hasSideEffects' => true],
 	'ftell' => ['hasSideEffects' => false],
-	'ftok' => ['hasSideEffects' => false],
+	'ftok' => ['hasSideEffects' => true],
 	'ftruncate' => ['hasSideEffects' => true],
 	'func_get_arg' => ['hasSideEffects' => false],
 	'func_get_args' => ['hasSideEffects' => false],
 	'func_num_args' => ['hasSideEffects' => false],
 	'function_exists' => ['hasSideEffects' => false],
 	'fwrite' => ['hasSideEffects' => true],
-	'gc_enabled' => ['hasSideEffects' => false],
-	'gc_status' => ['hasSideEffects' => false],
+	'gc_enabled' => ['hasSideEffects' => true],
+	'gc_status' => ['hasSideEffects' => true],
 	'gd_info' => ['hasSideEffects' => false],
 	'geoip_continent_code_by_name' => ['hasSideEffects' => false],
 	'geoip_country_code3_by_name' => ['hasSideEffects' => false],
@@ -948,41 +948,41 @@
 	'geoip_region_by_name' => ['hasSideEffects' => false],
 	'geoip_region_name_by_code' => ['hasSideEffects' => false],
 	'geoip_time_zone_by_country_and_region' => ['hasSideEffects' => false],
-	'get_browser' => ['hasSideEffects' => false],
+	'get_browser' => ['hasSideEffects' => true],
 	'get_called_class' => ['hasSideEffects' => false],
 	'get_cfg_var' => ['hasSideEffects' => false],
 	'get_class' => ['hasSideEffects' => false],
 	'get_class_methods' => ['hasSideEffects' => false],
 	'get_class_vars' => ['hasSideEffects' => false],
-	'get_current_user' => ['hasSideEffects' => false],
+	'get_current_user' => ['hasSideEffects' => true],
 	'get_debug_type' => ['hasSideEffects' => false],
-	'get_declared_classes' => ['hasSideEffects' => false],
-	'get_declared_interfaces' => ['hasSideEffects' => false],
-	'get_declared_traits' => ['hasSideEffects' => false],
-	'get_defined_constants' => ['hasSideEffects' => false],
-	'get_defined_functions' => ['hasSideEffects' => false],
-	'get_defined_vars' => ['hasSideEffects' => false],
+	'get_declared_classes' => ['hasSideEffects' => true],
+	'get_declared_interfaces' => ['hasSideEffects' => true],
+	'get_declared_traits' => ['hasSideEffects' => true],
+	'get_defined_constants' => ['hasSideEffects' => true],
+	'get_defined_functions' => ['hasSideEffects' => true],
+	'get_defined_vars' => ['hasSideEffects' => true],
 	'get_extension_funcs' => ['hasSideEffects' => false],
-	'get_headers' => ['hasSideEffects' => false],
+	'get_headers' => ['hasSideEffects' => true],
 	'get_html_translation_table' => ['hasSideEffects' => false],
-	'get_include_path' => ['hasSideEffects' => false],
-	'get_included_files' => ['hasSideEffects' => false],
+	'get_include_path' => ['hasSideEffects' => true],
+	'get_included_files' => ['hasSideEffects' => true],
 	'get_loaded_extensions' => ['hasSideEffects' => false],
-	'get_meta_tags' => ['hasSideEffects' => false],
+	'get_meta_tags' => ['hasSideEffects' => true],
 	'get_object_vars' => ['hasSideEffects' => false],
 	'get_parent_class' => ['hasSideEffects' => false],
-	'get_required_files' => ['hasSideEffects' => false],
+	'get_required_files' => ['hasSideEffects' => true],
 	'get_resource_id' => ['hasSideEffects' => false],
-	'get_resources' => ['hasSideEffects' => false],
+	'get_resources' => ['hasSideEffects' => true],
 	'getallheaders' => ['hasSideEffects' => false],
-	'getcwd' => ['hasSideEffects' => false],
-	'getdate' => ['hasSideEffects' => false],
-	'getenv' => ['hasSideEffects' => false],
+	'getcwd' => ['hasSideEffects' => true],
+	'getdate' => ['hasSideEffects' => true],
+	'getenv' => ['hasSideEffects' => true],
 	'gethostbyaddr' => ['hasSideEffects' => false],
 	'gethostbyname' => ['hasSideEffects' => false],
 	'gethostbynamel' => ['hasSideEffects' => false],
 	'gethostname' => ['hasSideEffects' => false],
-	'getlastmod' => ['hasSideEffects' => false],
+	'getlastmod' => ['hasSideEffects' => true],
 	'getmygid' => ['hasSideEffects' => false],
 	'getmyinode' => ['hasSideEffects' => false],
 	'getmypid' => ['hasSideEffects' => false],
@@ -990,15 +990,15 @@
 	'getprotobyname' => ['hasSideEffects' => false],
 	'getprotobynumber' => ['hasSideEffects' => false],
 	'getrandmax' => ['hasSideEffects' => false],
-	'getrusage' => ['hasSideEffects' => false],
+	'getrusage' => ['hasSideEffects' => true],
 	'getservbyname' => ['hasSideEffects' => false],
 	'getservbyport' => ['hasSideEffects' => false],
 	'gettext' => ['hasSideEffects' => false],
-	'gettimeofday' => ['hasSideEffects' => false],
+	'gettimeofday' => ['hasSideEffects' => true],
 	'gettype' => ['hasSideEffects' => false],
-	'glob' => ['hasSideEffects' => false],
-	'gmdate' => ['hasSideEffects' => false],
-	'gmmktime' => ['hasSideEffects' => false],
+	'glob' => ['hasSideEffects' => true],
+	'gmdate' => ['hasSideEffects' => true],
+	'gmmktime' => ['hasSideEffects' => true],
 	'gmp_abs' => ['hasSideEffects' => false],
 	'gmp_add' => ['hasSideEffects' => false],
 	'gmp_and' => ['hasSideEffects' => false],
@@ -1073,7 +1073,7 @@
 	'headers_list' => ['hasSideEffects' => false],
 	'hebrev' => ['hasSideEffects' => false],
 	'hexdec' => ['hasSideEffects' => false],
-	'hrtime' => ['hasSideEffects' => false],
+	'hrtime' => ['hasSideEffects' => true],
 	'html_entity_decode' => ['hasSideEffects' => false],
 	'htmlentities' => ['hasSideEffects' => false],
 	'htmlspecialchars' => ['hasSideEffects' => false],
@@ -1111,7 +1111,7 @@
 	'iconv_strpos' => ['hasSideEffects' => false],
 	'iconv_strrpos' => ['hasSideEffects' => false],
 	'iconv_substr' => ['hasSideEffects' => false],
-	'idate' => ['hasSideEffects' => false],
+	'idate' => ['hasSideEffects' => true],
 	'image_type_to_extension' => ['hasSideEffects' => false],
 	'image_type_to_mime_type' => ['hasSideEffects' => false],
 	'imagecolorat' => ['hasSideEffects' => false],
@@ -1146,13 +1146,13 @@
 	'inflate_get_status' => ['hasSideEffects' => false],
 	'inflate_init' => ['hasSideEffects' => false],
 	'ini_get' => ['hasSideEffects' => false],
-	'ini_get_all' => ['hasSideEffects' => false],
+	'ini_get_all' => ['hasSideEffects' => true],
 	'intcal_get_maximum' => ['hasSideEffects' => false],
 	'intdiv' => ['hasSideEffects' => false],
 	'intl_error_name' => ['hasSideEffects' => false],
 	'intl_get' => ['hasSideEffects' => false],
-	'intl_get_error_code' => ['hasSideEffects' => false],
-	'intl_get_error_message' => ['hasSideEffects' => false],
+	'intl_get_error_code' => ['hasSideEffects' => true],
+	'intl_get_error_message' => ['hasSideEffects' => true],
 	'intl_is_failure' => ['hasSideEffects' => false],
 	'intlcal_after' => ['hasSideEffects' => false],
 	'intlcal_before' => ['hasSideEffects' => false],
@@ -1165,8 +1165,8 @@
 	'intlcal_get_actual_minimum' => ['hasSideEffects' => false],
 	'intlcal_get_available_locales' => ['hasSideEffects' => false],
 	'intlcal_get_day_of_week_type' => ['hasSideEffects' => false],
-	'intlcal_get_error_code' => ['hasSideEffects' => false],
-	'intlcal_get_error_message' => ['hasSideEffects' => false],
+	'intlcal_get_error_code' => ['hasSideEffects' => true],
+	'intlcal_get_error_message' => ['hasSideEffects' => true],
 	'intlcal_get_first_day_of_week' => ['hasSideEffects' => false],
 	'intlcal_get_greatest_minimum' => ['hasSideEffects' => false],
 	'intlcal_get_keyword_values_for_locale' => ['hasSideEffects' => false],
@@ -1175,7 +1175,7 @@
 	'intlcal_get_maximum' => ['hasSideEffects' => false],
 	'intlcal_get_minimal_days_in_first_week' => ['hasSideEffects' => false],
 	'intlcal_get_minimum' => ['hasSideEffects' => false],
-	'intlcal_get_now' => ['hasSideEffects' => false],
+	'intlcal_get_now' => ['hasSideEffects' => true],
 	'intlcal_get_repeated_wall_time_option' => ['hasSideEffects' => false],
 	'intlcal_get_skipped_wall_time_option' => ['hasSideEffects' => false],
 	'intlcal_get_time' => ['hasSideEffects' => false],
@@ -1202,8 +1202,8 @@
 	'intltz_get_display_name' => ['hasSideEffects' => false],
 	'intltz_get_dst_savings' => ['hasSideEffects' => false],
 	'intltz_get_equivalent_id' => ['hasSideEffects' => false],
-	'intltz_get_error_code' => ['hasSideEffects' => false],
-	'intltz_get_error_message' => ['hasSideEffects' => false],
+	'intltz_get_error_code' => ['hasSideEffects' => true],
+	'intltz_get_error_message' => ['hasSideEffects' => true],
 	'intltz_get_gmt' => ['hasSideEffects' => false],
 	'intltz_get_id' => ['hasSideEffects' => false],
 	'intltz_get_offset' => ['hasSideEffects' => false],
@@ -1245,7 +1245,7 @@
 	'is_scalar' => ['hasSideEffects' => false],
 	'is_string' => ['hasSideEffects' => false],
 	'is_subclass_of' => ['hasSideEffects' => false],
-	'is_uploaded_file' => ['hasSideEffects' => false],
+	'is_uploaded_file' => ['hasSideEffects' => true],
 	'is_writable' => ['hasSideEffects' => false],
 	'is_writeable' => ['hasSideEffects' => false],
 	'iterator_count' => ['hasSideEffects' => false],
@@ -1258,10 +1258,10 @@
 	'lcfirst' => ['hasSideEffects' => false],
 	'lchgrp' => ['hasSideEffects' => true],
 	'lchown' => ['hasSideEffects' => true],
-	'libxml_get_errors' => ['hasSideEffects' => false],
-	'libxml_get_last_error' => ['hasSideEffects' => false],
+	'libxml_get_errors' => ['hasSideEffects' => true],
+	'libxml_get_last_error' => ['hasSideEffects' => true],
 	'link' => ['hasSideEffects' => true],
-	'linkinfo' => ['hasSideEffects' => false],
+	'linkinfo' => ['hasSideEffects' => true],
 	'locale_accept_from_http' => ['hasSideEffects' => false],
 	'locale_canonicalize' => ['hasSideEffects' => false],
 	'locale_compose' => ['hasSideEffects' => false],
@@ -1279,8 +1279,8 @@
 	'locale_get_script' => ['hasSideEffects' => false],
 	'locale_lookup' => ['hasSideEffects' => false],
 	'locale_parse' => ['hasSideEffects' => false],
-	'localeconv' => ['hasSideEffects' => false],
-	'localtime' => ['hasSideEffects' => false],
+	'localeconv' => ['hasSideEffects' => true],
+	'localtime' => ['hasSideEffects' => true],
 	'log' => ['hasSideEffects' => false],
 	'log10' => ['hasSideEffects' => false],
 	'log1p' => ['hasSideEffects' => false],
@@ -1336,9 +1336,9 @@
 	'mb_substr_count' => ['hasSideEffects' => false],
 	'mbereg_search_setpos' => ['hasSideEffects' => false],
 	'md5' => ['hasSideEffects' => false],
-	'md5_file' => ['hasSideEffects' => false],
-	'memory_get_peak_usage' => ['hasSideEffects' => false],
-	'memory_get_usage' => ['hasSideEffects' => false],
+	'md5_file' => ['hasSideEffects' => true],
+	'memory_get_peak_usage' => ['hasSideEffects' => true],
+	'memory_get_usage' => ['hasSideEffects' => true],
 	'metaphone' => ['hasSideEffects' => false],
 	'method_exists' => ['hasSideEffects' => false],
 	'mhash' => ['hasSideEffects' => false],
@@ -1346,16 +1346,16 @@
 	'mhash_get_block_size' => ['hasSideEffects' => false],
 	'mhash_get_hash_name' => ['hasSideEffects' => false],
 	'mhash_keygen_s2k' => ['hasSideEffects' => false],
-	'microtime' => ['hasSideEffects' => false],
+	'microtime' => ['hasSideEffects' => true],
 	'min' => ['hasSideEffects' => false],
 	'mkdir' => ['hasSideEffects' => true],
-	'mktime' => ['hasSideEffects' => false],
+	'mktime' => ['hasSideEffects' => true],
 	'move_uploaded_file' => ['hasSideEffects' => true],
 	'msgfmt_create' => ['hasSideEffects' => false],
 	'msgfmt_format' => ['hasSideEffects' => false],
 	'msgfmt_format_message' => ['hasSideEffects' => false],
-	'msgfmt_get_error_code' => ['hasSideEffects' => false],
-	'msgfmt_get_error_message' => ['hasSideEffects' => false],
+	'msgfmt_get_error_code' => ['hasSideEffects' => true],
+	'msgfmt_get_error_message' => ['hasSideEffects' => true],
 	'msgfmt_get_locale' => ['hasSideEffects' => false],
 	'msgfmt_get_pattern' => ['hasSideEffects' => false],
 	'msgfmt_parse' => ['hasSideEffects' => false],
@@ -1365,7 +1365,7 @@
 	'net_get_interfaces' => ['hasSideEffects' => false],
 	'ngettext' => ['hasSideEffects' => false],
 	'nl2br' => ['hasSideEffects' => false],
-	'nl_langinfo' => ['hasSideEffects' => false],
+	'nl_langinfo' => ['hasSideEffects' => true],
 	'normalizer_get_raw_decomposition' => ['hasSideEffects' => false],
 	'normalizer_is_normalized' => ['hasSideEffects' => false],
 	'normalizer_normalize' => ['hasSideEffects' => false],
@@ -1374,28 +1374,39 @@
 	'numfmt_format' => ['hasSideEffects' => false],
 	'numfmt_format_currency' => ['hasSideEffects' => false],
 	'numfmt_get_attribute' => ['hasSideEffects' => false],
-	'numfmt_get_error_code' => ['hasSideEffects' => false],
-	'numfmt_get_error_message' => ['hasSideEffects' => false],
+	'numfmt_get_error_code' => ['hasSideEffects' => true],
+	'numfmt_get_error_message' => ['hasSideEffects' => true],
 	'numfmt_get_locale' => ['hasSideEffects' => false],
 	'numfmt_get_pattern' => ['hasSideEffects' => false],
 	'numfmt_get_symbol' => ['hasSideEffects' => false],
 	'numfmt_get_text_attribute' => ['hasSideEffects' => false],
 	'numfmt_parse' => ['hasSideEffects' => false],
+	'ob_clean' => ['hasSideEffects' => true],
+	'ob_end_clean' => ['hasSideEffects' => true],
+	'ob_end_flush' => ['hasSideEffects' => true],
 	'ob_etaghandler' => ['hasSideEffects' => false],
-	'ob_get_contents' => ['hasSideEffects' => false],
+	'ob_flush' => ['hasSideEffects' => true],
+	'ob_get_clean' => ['hasSideEffects' => true],
+	'ob_get_contents' => ['hasSideEffects' => true],
+	'ob_get_length' => ['hasSideEffects' => true],
+	'ob_get_level' => ['hasSideEffects' => true],
+	'ob_get_status' => ['hasSideEffects' => true],
 	'ob_iconv_handler' => ['hasSideEffects' => false],
+	'ob_list_handlers' => ['hasSideEffects' => true],
 	'octdec' => ['hasSideEffects' => false],
 	'ord' => ['hasSideEffects' => false],
+	'output_add_rewrite_var' => ['hasSideEffects' => true],
+	'output_reset_rewrite_vars' => ['hasSideEffects' => true],
 	'pack' => ['hasSideEffects' => false],
 	'pam_auth' => ['hasSideEffects' => false],
 	'pam_chpass' => ['hasSideEffects' => false],
-	'parse_ini_file' => ['hasSideEffects' => false],
+	'parse_ini_file' => ['hasSideEffects' => true],
 	'parse_ini_string' => ['hasSideEffects' => false],
 	'parse_url' => ['hasSideEffects' => false],
-	'pathinfo' => ['hasSideEffects' => false],
+	'pathinfo' => ['hasSideEffects' => true],
 	'pclose' => ['hasSideEffects' => true],
-	'pcntl_errno' => ['hasSideEffects' => false],
-	'pcntl_get_last_error' => ['hasSideEffects' => false],
+	'pcntl_errno' => ['hasSideEffects' => true],
+	'pcntl_get_last_error' => ['hasSideEffects' => true],
 	'pcntl_getpriority' => ['hasSideEffects' => false],
 	'pcntl_strerror' => ['hasSideEffects' => false],
 	'pcntl_wexitstatus' => ['hasSideEffects' => false],
@@ -1410,16 +1421,16 @@
 	'php_ini_scanned_files' => ['hasSideEffects' => false],
 	'php_logo_guid' => ['hasSideEffects' => false],
 	'php_sapi_name' => ['hasSideEffects' => false],
-	'php_strip_whitespace' => ['hasSideEffects' => false],
-	'php_uname' => ['hasSideEffects' => false],
+	'php_strip_whitespace' => ['hasSideEffects' => true],
+	'php_uname' => ['hasSideEffects' => true],
 	'phpversion' => ['hasSideEffects' => false],
 	'pi' => ['hasSideEffects' => false],
 	'popen' => ['hasSideEffects' => true],
 	'pos' => ['hasSideEffects' => false],
 	'posix_ctermid' => ['hasSideEffects' => false],
-	'posix_errno' => ['hasSideEffects' => false],
-	'posix_get_last_error' => ['hasSideEffects' => false],
-	'posix_getcwd' => ['hasSideEffects' => false],
+	'posix_errno' => ['hasSideEffects' => true],
+	'posix_get_last_error' => ['hasSideEffects' => true],
+	'posix_getcwd' => ['hasSideEffects' => true],
 	'posix_getegid' => ['hasSideEffects' => false],
 	'posix_geteuid' => ['hasSideEffects' => false],
 	'posix_getgid' => ['hasSideEffects' => false],
@@ -1444,8 +1455,8 @@
 	'posix_uname' => ['hasSideEffects' => false],
 	'pow' => ['hasSideEffects' => false],
 	'preg_grep' => ['hasSideEffects' => false],
-	'preg_last_error' => ['hasSideEffects' => false],
-	'preg_last_error_msg' => ['hasSideEffects' => false],
+	'preg_last_error' => ['hasSideEffects' => true],
+	'preg_last_error_msg' => ['hasSideEffects' => true],
 	'preg_quote' => ['hasSideEffects' => false],
 	'preg_split' => ['hasSideEffects' => false],
 	'property_exists' => ['hasSideEffects' => false],
@@ -1460,23 +1471,23 @@
 	'rawurldecode' => ['hasSideEffects' => false],
 	'rawurlencode' => ['hasSideEffects' => false],
 	'readfile' => ['hasSideEffects' => true],
-	'readlink' => ['hasSideEffects' => false],
-	'realpath' => ['hasSideEffects' => false],
-	'realpath_cache_get' => ['hasSideEffects' => false],
-	'realpath_cache_size' => ['hasSideEffects' => false],
+	'readlink' => ['hasSideEffects' => true],
+	'realpath' => ['hasSideEffects' => true],
+	'realpath_cache_get' => ['hasSideEffects' => true],
+	'realpath_cache_size' => ['hasSideEffects' => true],
 	'rename' => ['hasSideEffects' => true],
 	'resourcebundle_count' => ['hasSideEffects' => false],
 	'resourcebundle_create' => ['hasSideEffects' => false],
 	'resourcebundle_get' => ['hasSideEffects' => false],
-	'resourcebundle_get_error_code' => ['hasSideEffects' => false],
-	'resourcebundle_get_error_message' => ['hasSideEffects' => false],
+	'resourcebundle_get_error_code' => ['hasSideEffects' => true],
+	'resourcebundle_get_error_message' => ['hasSideEffects' => true],
 	'resourcebundle_locales' => ['hasSideEffects' => false],
 	'rewind' => ['hasSideEffects' => true],
 	'rmdir' => ['hasSideEffects' => true],
 	'round' => ['hasSideEffects' => false],
 	'rtrim' => ['hasSideEffects' => false],
 	'sha1' => ['hasSideEffects' => false],
-	'sha1_file' => ['hasSideEffects' => false],
+	'sha1_file' => ['hasSideEffects' => true],
 	'sin' => ['hasSideEffects' => false],
 	'sinh' => ['hasSideEffects' => false],
 	'sizeof' => ['hasSideEffects' => false],
@@ -1502,9 +1513,9 @@
 	'strcmp' => ['hasSideEffects' => false],
 	'strcoll' => ['hasSideEffects' => false],
 	'strcspn' => ['hasSideEffects' => false],
-	'stream_get_filters' => ['hasSideEffects' => false],
-	'stream_get_transports' => ['hasSideEffects' => false],
-	'stream_get_wrappers' => ['hasSideEffects' => false],
+	'stream_get_filters' => ['hasSideEffects' => true],
+	'stream_get_transports' => ['hasSideEffects' => true],
+	'stream_get_wrappers' => ['hasSideEffects' => true],
 	'stream_is_local' => ['hasSideEffects' => false],
 	'stream_isatty' => ['hasSideEffects' => false],
 	'strip_tags' => ['hasSideEffects' => false],
@@ -1519,7 +1530,7 @@
 	'strncmp' => ['hasSideEffects' => false],
 	'strpbrk' => ['hasSideEffects' => false],
 	'strpos' => ['hasSideEffects' => false],
-	'strptime' => ['hasSideEffects' => false],
+	'strptime' => ['hasSideEffects' => true],
 	'strrchr' => ['hasSideEffects' => false],
 	'strrev' => ['hasSideEffects' => false],
 	'strripos' => ['hasSideEffects' => false],
@@ -1527,7 +1538,7 @@
 	'strspn' => ['hasSideEffects' => false],
 	'strstr' => ['hasSideEffects' => false],
 	'strtolower' => ['hasSideEffects' => false],
-	'strtotime' => ['hasSideEffects' => false],
+	'strtotime' => ['hasSideEffects' => true],
 	'strtoupper' => ['hasSideEffects' => false],
 	'strtr' => ['hasSideEffects' => false],
 	'strval' => ['hasSideEffects' => false],
@@ -1536,18 +1547,18 @@
 	'substr_count' => ['hasSideEffects' => false],
 	'substr_replace' => ['hasSideEffects' => false],
 	'symlink' => ['hasSideEffects' => true],
-	'sys_getloadavg' => ['hasSideEffects' => false],
+	'sys_getloadavg' => ['hasSideEffects' => true],
 	'tan' => ['hasSideEffects' => false],
 	'tanh' => ['hasSideEffects' => false],
 	'tempnam' => ['hasSideEffects' => true],
 	'timezone_abbreviations_list' => ['hasSideEffects' => false],
-	'timezone_identifiers_list' => ['hasSideEffects' => false],
-	'timezone_location_get' => ['hasSideEffects' => false],
-	'timezone_name_from_abbr' => ['hasSideEffects' => false],
+	'timezone_identifiers_list' => ['hasSideEffects' => true],
+	'timezone_location_get' => ['hasSideEffects' => true],
+	'timezone_name_from_abbr' => ['hasSideEffects' => true],
 	'timezone_name_get' => ['hasSideEffects' => false],
-	'timezone_offset_get' => ['hasSideEffects' => false],
-	'timezone_open' => ['hasSideEffects' => false],
-	'timezone_transitions_get' => ['hasSideEffects' => false],
+	'timezone_offset_get' => ['hasSideEffects' => true],
+	'timezone_open' => ['hasSideEffects' => true],
+	'timezone_transitions_get' => ['hasSideEffects' => true],
 	'timezone_version_get' => ['hasSideEffects' => false],
 	'tmpfile' => ['hasSideEffects' => true],
 	'token_get_all' => ['hasSideEffects' => false],
@@ -1556,8 +1567,8 @@
 	'transliterator_create' => ['hasSideEffects' => false],
 	'transliterator_create_from_rules' => ['hasSideEffects' => false],
 	'transliterator_create_inverse' => ['hasSideEffects' => false],
-	'transliterator_get_error_code' => ['hasSideEffects' => false],
-	'transliterator_get_error_message' => ['hasSideEffects' => false],
+	'transliterator_get_error_code' => ['hasSideEffects' => true],
+	'transliterator_get_error_message' => ['hasSideEffects' => true],
 	'transliterator_list_ids' => ['hasSideEffects' => false],
 	'transliterator_transliterate' => ['hasSideEffects' => false],
 	'trim' => ['hasSideEffects' => false],