Fix #806 - allow specification of functions and static methods that exit

config.xsd

@@ -14,6 +14,7 @@
             <xs:element name="mockClasses" type="MockClassesType" minOccurs="0" maxOccurs="1" />
             <xs:element name="stubs" type="StubsType" minOccurs="0" maxOccurs="1" />
             <xs:element name="plugins" type="PluginsType" minOccurs="0" maxOccurs="1" />
+            <xs:element name="exitFunctions" type="ExitFunctionsType" minOccurs="0" maxOccurs="1" />
             <xs:element name="issueHandlers" type="IssueHandlersType" minOccurs="0" maxOccurs="1" />
             <xs:element name="ignoreExceptions" type="ExceptionsType" minOccurs="0" maxOccurs="1" />
         </xs:choice>
@@ -92,6 +93,12 @@
         </xs:sequence>
     </xs:complexType>
 
+    <xs:complexType name="ExitFunctionsType">
+        <xs:sequence>
+            <xs:element name="function" maxOccurs="unbounded" type="NameAttributeType" />
+        </xs:sequence>
+    </xs:complexType>
+
     <xs:complexType name="PluginsType">
         <xs:sequence>
             <xs:element name="plugin" maxOccurs="unbounded">

src/Psalm/Checker/FunctionLike/ReturnTypeChecker.php

@@ -100,7 +100,10 @@ class ReturnTypeChecker
         );
 
         if ((!$return_type || $return_type->from_docblock)
-            && ScopeChecker::getFinalControlActions($function_stmts) !== [ScopeChecker::ACTION_END]
+            && ScopeChecker::getFinalControlActions(
+                $function_stmts,
+                $project_checker->config->exit_functions
+            ) !== [ScopeChecker::ACTION_END]
             && !$inferred_yield_types
             && count($inferred_return_type_parts)
         ) {
@@ -119,7 +122,10 @@ class ReturnTypeChecker
             && !$return_type->from_docblock
             && !$return_type->isVoid()
             && !$inferred_yield_types
-            && ScopeChecker::getFinalControlActions($function_stmts) !== [ScopeChecker::ACTION_END]
+            && ScopeChecker::getFinalControlActions(
+                $function_stmts,
+                $project_checker->config->exit_functions
+            ) !== [ScopeChecker::ACTION_END]
         ) {
             if (IssueBuffer::accepts(
                 new InvalidReturnType(

src/Psalm/Checker/ScopeChecker.php

@@ -59,6 +59,7 @@ class ScopeChecker
      */
     public static function getFinalControlActions(
         array $stmts,
+        array $exit_functions,
         $in_switch = false,
         $return_is_exit = true
     ) {
@@ -82,6 +83,36 @@ class ScopeChecker
                 return [self::ACTION_END];
             }
 
+            if ($stmt instanceof PhpParser\Node\Stmt\Expression) {
+                if ($exit_functions) {
+                    if ($stmt->expr instanceof PhpParser\Node\Expr\FuncCall
+                        || $stmt->expr instanceof PhpParser\Node\Expr\StaticCall
+                    ) {
+                        if ($stmt->expr instanceof PhpParser\Node\Expr\FuncCall) {
+                            /** @var string|null */
+                            $resolved_name = $stmt->expr->name->getAttribute('resolvedName');
+
+                            if ($resolved_name && isset($exit_functions[strtolower($resolved_name)])) {
+                                return [self::ACTION_END];
+                            }
+                        } elseif ($stmt->expr->class instanceof PhpParser\Node\Name
+                            && $stmt->expr->name instanceof PhpParser\Node\Identifier
+                        ) {
+                            /** @var string|null */
+                            $resolved_class_name = $stmt->expr->class->getAttribute('resolvedName');
+
+                            if ($resolved_class_name
+                                && isset($exit_functions[strtolower($resolved_class_name . '::' . $stmt->expr->name)])
+                            ) {
+                                return [self::ACTION_END];
+                            }
+                        }
+                    }
+                }
+
+                continue;
+            }
+
             if ($stmt instanceof PhpParser\Node\Stmt\Continue_) {
                 if ($in_switch
                     && (!$stmt->num || !$stmt->num instanceof PhpParser\Node\Scalar\LNumber || $stmt->num->value < 2)
@@ -103,9 +134,9 @@ class ScopeChecker
             }
 
             if ($stmt instanceof PhpParser\Node\Stmt\If_) {
-                $if_statement_actions = self::getFinalControlActions($stmt->stmts, $in_switch);
+                $if_statement_actions = self::getFinalControlActions($stmt->stmts, $exit_functions, $in_switch);
                 $else_statement_actions = $stmt->else
-                    ? self::getFinalControlActions($stmt->else->stmts, $in_switch)
+                    ? self::getFinalControlActions($stmt->else->stmts, $exit_functions, $in_switch)
                     : [];
 
                 $all_same = count($if_statement_actions) === 1
@@ -116,7 +147,11 @@ class ScopeChecker
 
                 if ($stmt->elseifs) {
                     foreach ($stmt->elseifs as $elseif) {
-                        $elseif_control_actions = self::getFinalControlActions($elseif->stmts, $in_switch);
+                        $elseif_control_actions = self::getFinalControlActions(
+                            $elseif->stmts,
+                            $exit_functions,
+                            $in_switch
+                        );
 
                         $all_same = $all_same && $elseif_control_actions == $if_statement_actions;
 
@@ -147,7 +182,7 @@ class ScopeChecker
                 for ($d = count($stmt->cases) - 1; $d >= 0; --$d) {
                     $case = $stmt->cases[$d];
 
-                    $case_actions = self::getFinalControlActions($case->stmts, true);
+                    $case_actions = self::getFinalControlActions($case->stmts, $exit_functions, true);
 
                     if (array_intersect([
                         self::ACTION_LEAVE_SWITCH,
@@ -183,11 +218,14 @@ class ScopeChecker
             }
 
             if ($stmt instanceof PhpParser\Node\Stmt\While_) {
-                $control_actions = array_merge(self::getFinalControlActions($stmt->stmts), $control_actions);
+                $control_actions = array_merge(
+                    self::getFinalControlActions($stmt->stmts, $exit_functions),
+                    $control_actions
+                );
             }
 
             if ($stmt instanceof PhpParser\Node\Stmt\Do_) {
-                $do_actions = self::getFinalControlActions($stmt->stmts);
+                $do_actions = self::getFinalControlActions($stmt->stmts, $exit_functions);
 
                 if (count($do_actions) && !in_array(self::ACTION_NONE, $do_actions, true)) {
                     return $do_actions;
@@ -197,13 +235,13 @@ class ScopeChecker
             }
 
             if ($stmt instanceof PhpParser\Node\Stmt\TryCatch) {
-                $try_statement_actions = self::getFinalControlActions($stmt->stmts, $in_switch);
+                $try_statement_actions = self::getFinalControlActions($stmt->stmts, $exit_functions, $in_switch);
 
                 if ($stmt->catches) {
                     $all_same = count($try_statement_actions) === 1;
 
                     foreach ($stmt->catches as $catch) {
-                        $catch_actions = self::getFinalControlActions($catch->stmts, $in_switch);
+                        $catch_actions = self::getFinalControlActions($catch->stmts, $exit_functions, $in_switch);
 
                         $all_same = $all_same && $try_statement_actions == $catch_actions;
 
@@ -221,6 +259,7 @@ class ScopeChecker
                     if ($stmt->finally->stmts) {
                         $finally_statement_actions = self::getFinalControlActions(
                             $stmt->finally->stmts,
+                            $exit_functions,
                             $in_switch
                         );
 

src/Psalm/Checker/Statements/Block/IfChecker.php

@@ -536,7 +536,13 @@ class IfChecker
         Context $outer_context,
         array $pre_assignment_else_redefined_vars
     ) {
-        $final_actions = ScopeChecker::getFinalControlActions($stmt->stmts, $outer_context->inside_case);
+        $project_checker = $statements_checker->getFileChecker()->project_checker;
+
+        $final_actions = ScopeChecker::getFinalControlActions(
+            $stmt->stmts,
+            $project_checker->config->exit_functions,
+            $outer_context->inside_case
+        );
 
         $has_ending_statements = $final_actions === [ScopeChecker::ACTION_END];
 
@@ -553,8 +559,6 @@ class IfChecker
 
         $if_scope->final_actions = $final_actions;
 
-        $project_checker = $statements_checker->getFileChecker()->project_checker;
-
         $assigned_var_ids = $if_context->assigned_var_ids;
         $possibly_assigned_var_ids = $if_context->possibly_assigned_var_ids;
         $if_context->assigned_var_ids = [];
@@ -1051,7 +1055,11 @@ class IfChecker
             }
         }
 
-        $final_actions = ScopeChecker::getFinalControlActions($elseif->stmts, $outer_context->inside_case);
+        $final_actions = ScopeChecker::getFinalControlActions(
+            $elseif->stmts,
+            $project_checker->config->exit_functions,
+            $outer_context->inside_case
+        );
         // has a return/throw at end
         $has_ending_statements = $final_actions === [ScopeChecker::ACTION_END];
         $has_leaving_statements = $has_ending_statements
@@ -1419,7 +1427,11 @@ class IfChecker
         }
 
         $final_actions = $else
-            ? ScopeChecker::getFinalControlActions($else->stmts, $outer_context->inside_case)
+            ? ScopeChecker::getFinalControlActions(
+                $else->stmts,
+                $project_checker->config->exit_functions,
+                $outer_context->inside_case
+            )
             : [ScopeChecker::ACTION_NONE];
         // has a return/throw at end
         $has_ending_statements = $final_actions === [ScopeChecker::ACTION_END];

src/Psalm/Checker/Statements/Block/LoopChecker.php

@@ -7,6 +7,7 @@ use Psalm\Checker\Statements\ExpressionChecker;
 use Psalm\Checker\StatementsChecker;
 use Psalm\Clause;
 use Psalm\CodeLocation;
+use Psalm\Config;
 use Psalm\Context;
 use Psalm\IssueBuffer;
 use Psalm\Scope\LoopScope;
@@ -72,7 +73,7 @@ class LoopChecker
             );
         }
 
-        $final_actions = ScopeChecker::getFinalControlActions($stmts);
+        $final_actions = ScopeChecker::getFinalControlActions($stmts, Config::getInstance()->exit_functions);
         $has_break_statement = $final_actions === [ScopeChecker::ACTION_BREAK];
 
         if ($assignment_map) {

src/Psalm/Checker/Statements/Block/SwitchChecker.php

@@ -58,11 +58,17 @@ class SwitchChecker
 
         $case_action_map = [];
 
+        $config = \Psalm\Config::getInstance();
+
         // create a map of case statement -> ultimate exit type
         for ($i = count($stmt->cases) - 1; $i >= 0; --$i) {
             $case = $stmt->cases[$i];
 
-            $case_actions = $case_action_map[$i] = ScopeChecker::getFinalControlActions($case->stmts, true);
+            $case_actions = $case_action_map[$i] = ScopeChecker::getFinalControlActions(
+                $case->stmts,
+                $config->exit_functions,
+                true
+            );
 
             if (!in_array(ScopeChecker::ACTION_NONE, $case_actions, true)) {
                 if ($case_actions === [ScopeChecker::ACTION_END]) {

src/Psalm/Checker/Statements/Block/TryChecker.php

@@ -31,15 +31,15 @@ class TryChecker
         $catch_actions = [];
         $all_catches_leave = true;
 
-        /** @var int $i */
-        foreach ($stmt->catches as $i => $catch) {
-            $catch_actions[$i] = ScopeChecker::getFinalControlActions($catch->stmts);
-            $all_catches_leave = $all_catches_leave && !in_array(ScopeChecker::ACTION_NONE, $catch_actions[$i], true);
-        }
-
         $project_checker = $statements_checker->getFileChecker()->project_checker;
         $codebase = $project_checker->codebase;
 
+        /** @var int $i */
+        foreach ($stmt->catches as $i => $catch) {
+            $catch_actions[$i] = ScopeChecker::getFinalControlActions($catch->stmts, $codebase->config->exit_functions);
+            $all_catches_leave = $all_catches_leave && !in_array(ScopeChecker::ACTION_NONE, $catch_actions[$i], true);
+        }
+
         $existing_thrown_exceptions = $context->possibly_thrown_exceptions;
 
         /**

src/Psalm/Config.php

@@ -277,6 +277,13 @@ class Config
     /** @var ClassLoader|null */
     private $composer_class_loader;
 
+    /**
+     * Custom functions that always exit
+     *
+     * @var array<string, bool>
+     */
+    public $exit_functions = [];
+
     protected function __construct()
     {
         self::$instance = $this;
@@ -564,7 +571,14 @@ class Config
         if (isset($config_xml->ignoreExceptions) && isset($config_xml->ignoreExceptions->class)) {
             /** @var \SimpleXMLElement $exception_class */
             foreach ($config_xml->ignoreExceptions->class as $exception_class) {
-                $config->ignored_exceptions[(string)$exception_class ['name']] = true;
+                $config->ignored_exceptions[(string) $exception_class['name']] = true;
+            }
+        }
+
+        if (isset($config_xml->exitFunctions) && isset($config_xml->exitFunctions->function)) {
+            /** @var \SimpleXMLElement $exit_function */
+            foreach ($config_xml->exitFunctions->function as $exit_function) {
+                $config->exit_functions[strtolower((string) $exit_function['name'])] = true;
             }
         }
 

src/Psalm/Visitor/DependencyFinderVisitor.php

@@ -891,6 +891,7 @@ class DependencyFinderVisitor extends PhpParser\NodeVisitorAbstract implements P
                 if ($function_stmt instanceof PhpParser\Node\Stmt\If_) {
                     $final_actions = \Psalm\Checker\ScopeChecker::getFinalControlActions(
                         $function_stmt->stmts,
+                        $this->config->exit_functions,
                         false,
                         false
                     );

tests/ConfigTest.php

@@ -495,6 +495,76 @@ class ConfigTest extends TestCase
         $this->analyzeFile($file_path, new Context());
     }
 
+    /**
+     * @return void
+     */
+    public function testExitFunctions()
+    {
+        $this->project_checker = $this->getProjectCheckerWithConfig(
+            TestConfig::loadFromXML(
+                dirname(__DIR__),
+                '<?xml version="1.0"?>
+                <psalm>
+                    <exitFunctions>
+                        <function name="leave" />
+                        <function name="Foo\namespacedLeave" />
+                        <function name="Foo\Bar::staticLeave" />
+                    </exitFunctions>
+                </psalm>'
+            )
+        );
+
+        $file_path = getcwd() . '/src/somefile.php';
+
+        $this->addFile(
+            $file_path,
+            '<?php
+                namespace {
+                    function leave() : void {
+                        exit();
+                    }
+
+                    function mightLeave() : string {
+                        if (rand(0, 1)) {
+                            leave();
+                        } else {
+                            return "here";
+                        }
+                    }
+
+                    function mightLeaveWithNamespacedFunction() : string {
+                        if (rand(0, 1)) {
+                            \Foo\namespacedLeave();
+                        } else {
+                            return "here";
+                        }
+                    }
+
+                    function mightLeaveWithStaticMethod() : string {
+                        if (rand(0, 1)) {
+                            Foo\Bar::staticLeave();
+                        } else {
+                            return "here";
+                        }
+                    }
+                }
+
+                namespace Foo {
+                    function namespacedLeave() : void {
+                        exit();
+                    }
+
+                    class Bar {
+                        public static function staticLeave() : void {
+                            exit();
+                        }
+                    }
+                }'
+        );
+
+        $this->analyzeFile($file_path, new Context());
+    }
+
     /**
      * @return void
      */