feat: make break, continue and return be an expression

Zend/zend_compile.c

@@ -5673,7 +5673,7 @@ static bool zend_has_finally(void) /* {{{ */
 }
 /* }}} */
 
-static void zend_compile_return(zend_ast *ast) /* {{{ */
+static void zend_compile_return(znode *result, zend_ast *ast) /* {{{ */
 {
 	zend_ast *expr_ast = ast->child[0];
 	bool is_generator = (CG(active_op_array)->fn_flags & ZEND_ACC_GENERATOR) != 0;
@@ -5716,8 +5716,7 @@ static void zend_compile_return(zend_ast *ast) /* {{{ */
 
 	zend_handle_loops_and_finally((expr_node.op_type & (IS_TMP_VAR | IS_VAR)) ? &expr_node : NULL);
 
-	opline = zend_emit_op(NULL, by_ref ? ZEND_RETURN_BY_REF : ZEND_RETURN,
-		&expr_node, NULL);
+	opline = zend_emit_op(result, by_ref ? ZEND_RETURN_BY_REF : ZEND_RETURN, &expr_node, NULL);
 
 	if (by_ref && expr_ast) {
 		if (zend_is_call(expr_ast)) {
@@ -5759,7 +5758,7 @@ static void zend_compile_throw(znode *result, zend_ast *ast) /* {{{ */
 }
 /* }}} */
 
-static void zend_compile_break_continue(zend_ast *ast) /* {{{ */
+static void zend_compile_break_continue(znode *result, zend_ast *ast) /* {{{ */
 {
 	zend_ast *depth_ast = ast->child[0];
 
@@ -5830,7 +5829,7 @@ static void zend_compile_break_continue(zend_ast *ast) /* {{{ */
 		}
 	}
 
-	opline = zend_emit_op(NULL, ast->kind == ZEND_AST_BREAK ? ZEND_BRK : ZEND_CONT, NULL, NULL);
+	opline = zend_emit_op(result, ast->kind == ZEND_AST_BREAK ? ZEND_BRK : ZEND_CONT, NULL, NULL);
 	opline->op1.num = CG(context).current_brk_cont;
 	opline->op2.num = depth;
 }
@@ -11380,16 +11379,9 @@ static void zend_compile_stmt(zend_ast *ast) /* {{{ */
 		case ZEND_AST_UNSET:
 			zend_compile_unset(ast);
 			break;
-		case ZEND_AST_RETURN:
-			zend_compile_return(ast);
-			break;
 		case ZEND_AST_ECHO:
 			zend_compile_echo(ast);
 			break;
-		case ZEND_AST_BREAK:
-		case ZEND_AST_CONTINUE:
-			zend_compile_break_continue(ast);
-			break;
 		case ZEND_AST_GOTO:
 			zend_compile_goto(ast);
 			break;
@@ -11454,6 +11446,9 @@ static void zend_compile_stmt(zend_ast *ast) /* {{{ */
 		case ZEND_AST_HALT_COMPILER:
 			zend_compile_halt_compiler(ast);
 			break;
+		case ZEND_AST_RETURN:
+		case ZEND_AST_CONTINUE:
+		case ZEND_AST_BREAK:
 		case ZEND_AST_THROW:
 			zend_compile_expr(NULL, ast);
 			break;
@@ -11601,9 +11596,16 @@ static void zend_compile_expr_inner(znode *result, zend_ast *ast) /* {{{ */
 		case ZEND_AST_ARROW_FUNC:
 			zend_compile_func_decl(result, ast, FUNC_DECL_LEVEL_NESTED);
 			return;
+		case ZEND_AST_CONTINUE:
+		case ZEND_AST_BREAK:
+			zend_compile_break_continue(result, ast);
+			return;
 		case ZEND_AST_THROW:
 			zend_compile_throw(result, ast);
 			return;
+		case ZEND_AST_RETURN:
+			zend_compile_return(result, ast);
+			return;
 		case ZEND_AST_MATCH:
 			zend_compile_match(result, ast);
 			return;

Zend/zend_language_parser.y

@@ -51,7 +51,7 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %destructor { zend_ast_destroy($$); } <ast>
 %destructor { if ($$) zend_string_release_ex($$, 0); } <str>
 
-%precedence T_THROW
+%precedence T_RETURN T_BREAK T_CONTINUE T_THROW
 %precedence PREC_ARROW_FUNCTION
 %precedence T_INCLUDE T_INCLUDE_ONCE T_REQUIRE T_REQUIRE_ONCE
 %left T_LOGICAL_OR
@@ -511,9 +511,6 @@ statement:
 			{ $$ = zend_ast_create(ZEND_AST_FOR, $3, $5, $7, $9); }
 	|	T_SWITCH '(' expr ')' switch_case_list
 			{ $$ = zend_ast_create(ZEND_AST_SWITCH, $3, $5); }
-	|	T_BREAK optional_expr ';'		{ $$ = zend_ast_create(ZEND_AST_BREAK, $2); }
-	|	T_CONTINUE optional_expr ';'	{ $$ = zend_ast_create(ZEND_AST_CONTINUE, $2); }
-	|	T_RETURN optional_expr ';'		{ $$ = zend_ast_create(ZEND_AST_RETURN, $2); }
 	|	T_GLOBAL global_var_list ';'	{ $$ = $2; }
 	|	T_STATIC static_var_list ';'	{ $$ = $2; }
 	|	T_ECHO echo_expr_list ';'		{ $$ = $2; }
@@ -1317,16 +1314,22 @@ expr:
 		}
 	|	'@' expr			{ $$ = zend_ast_create(ZEND_AST_SILENCE, $2); }
 	|	scalar { $$ = $1; }
-	|	'`' backticks_expr '`' { $$ = zend_ast_create(ZEND_AST_SHELL_EXEC, $2); }
-	|	T_PRINT expr { $$ = zend_ast_create(ZEND_AST_PRINT, $2); }
-	|	T_YIELD { $$ = zend_ast_create(ZEND_AST_YIELD, NULL, NULL); CG(extra_fn_flags) |= ZEND_ACC_GENERATOR; }
-	|	T_YIELD expr { $$ = zend_ast_create(ZEND_AST_YIELD, $2, NULL); CG(extra_fn_flags) |= ZEND_ACC_GENERATOR; }
-	|	T_YIELD expr T_DOUBLE_ARROW expr { $$ = zend_ast_create(ZEND_AST_YIELD, $4, $2); CG(extra_fn_flags) |= ZEND_ACC_GENERATOR; }
-	|	T_YIELD_FROM expr { $$ = zend_ast_create(ZEND_AST_YIELD_FROM, $2); CG(extra_fn_flags) |= ZEND_ACC_GENERATOR; }
-	|	T_THROW expr { $$ = zend_ast_create(ZEND_AST_THROW, $2); }
-	|	inline_function { $$ = $1; }
-	|	attributes inline_function { $$ = zend_ast_with_attributes($2, $1); }
-	|	T_STATIC inline_function { $$ = $2; ((zend_ast_decl *) $$)->flags |= ZEND_ACC_STATIC; }
+	|	'`' backticks_expr '`' 				{ $$ = zend_ast_create(ZEND_AST_SHELL_EXEC, $2); }
+	|	T_PRINT expr 						{ $$ = zend_ast_create(ZEND_AST_PRINT, $2); }
+	|	T_YIELD 							{ $$ = zend_ast_create(ZEND_AST_YIELD, NULL, NULL); CG(extra_fn_flags) |= ZEND_ACC_GENERATOR; }
+	|	T_YIELD expr 						{ $$ = zend_ast_create(ZEND_AST_YIELD, $2, NULL); CG(extra_fn_flags) |= ZEND_ACC_GENERATOR; }
+	|	T_YIELD expr T_DOUBLE_ARROW expr 	{ $$ = zend_ast_create(ZEND_AST_YIELD, $4, $2); CG(extra_fn_flags) |= ZEND_ACC_GENERATOR; }
+	|	T_YIELD_FROM expr 				 	{ $$ = zend_ast_create(ZEND_AST_YIELD_FROM, $2); CG(extra_fn_flags) |= ZEND_ACC_GENERATOR; }
+	|	T_CONTINUE							{ $$ = zend_ast_create(ZEND_AST_CONTINUE, NULL); }
+	|	T_CONTINUE expr						{ $$ = zend_ast_create(ZEND_AST_CONTINUE, $2); }
+	|	T_BREAK								{ $$ = zend_ast_create(ZEND_AST_BREAK, NULL); }
+	|	T_BREAK expr						{ $$ = zend_ast_create(ZEND_AST_BREAK, $2); }
+	|	T_RETURN							{ $$ = zend_ast_create(ZEND_AST_RETURN, NULL); }
+	|	T_RETURN expr						{ $$ = zend_ast_create(ZEND_AST_RETURN, $2); }
+	|	T_THROW expr 						{ $$ = zend_ast_create(ZEND_AST_THROW, $2); }
+	|	inline_function 					{ $$ = $1; }
+	|	attributes inline_function 			{ $$ = zend_ast_with_attributes($2, $1); }
+	|	T_STATIC inline_function 			{ $$ = $2; ((zend_ast_decl *) $$)->flags |= ZEND_ACC_STATIC; }
 	|	attributes T_STATIC inline_function
 			{ $$ = zend_ast_with_attributes($3, $1); ((zend_ast_decl *) $$)->flags |= ZEND_ACC_STATIC; }
 	|	match { $$ = $1; }

tests/lang/early-return/001.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Early break
+--FILE--
+<?php
+function test($a,$b) {
+    $b ?? return 0;
+    $a ?: return 1;
+    $c = $a <= 0 ? return "negative" : $a*2;
+
+    return 2;
+}
+echo test(1, null);
+echo test(0, 1);
+echo test(-1, 1);
+echo test(3, 1);
+?>
+--EXPECT--
+01negative2

tests/lang/early-return/002.phpt

@@ -0,0 +1,46 @@
+--TEST--
+Early returns
+--FILE--
+<?php
+$tree = [];
+while (1) {
+    $tree = $tree['parent'] ?? break;
+}
+echo 'tree is null' . PHP_EOL;
+
+function getTopParent(array $tree) {
+    $parent = null;
+    while (1) {
+        $parent = $tree['parent'] ?? return $parent;
+        $tree = $parent;
+    }
+    return null;
+}
+var_dump(getTopParent([
+    'level' => 0,
+    'parent' => [
+        'level' => 1,
+        'parent' => null,
+    ]
+]));
+
+function test1($userOrNull, $subscriptionOrNull) {
+    $user = $userOrNull ?? return 1;
+    $subscription = $subscriptionOrNull ?? return 2;
+    $lastCard = $subscription->invoices[0]->charges[0]->cardDetails->card ?? return 3;
+
+    return 4;
+}
+echo test1(null,null);
+echo test1(new stdClass(),null);
+echo test1(new stdClass(),new stdClass());
+?>
+--EXPECT--
+tree is null
+array(2) {
+  ["level"]=>
+  int(1)
+  ["parent"]=>
+  NULL
+}
+123

tests/lang/early-return/003.phpt

@@ -0,0 +1,30 @@
+--TEST--
+Early operators mixed
+--FILE--
+<?php
+function test1(int $v) {
+    return $v = $v - 1 ?: return $v;
+}
+echo test1(3);
+echo test1(2);
+echo test1(1);
+echo test1(0);
+echo PHP_EOL;
+
+function test2(int $v, int $stop) {
+    while (true) {
+        $v-- ?: return $v;
+        $stop === $v ? return $v : continue;
+    }
+    return 'never here';
+}
+echo test2(10, 3);
+echo test2(10, 2);
+echo test2(10, 1);
+echo test2(10, 0);
+echo test2(10, -5);
+echo PHP_EOL;
+?>
+--EXPECT--
+211-1
+3210-1

tests/lang/early-return/match.phpt

@@ -0,0 +1,62 @@
+--TEST--
+Operators in match
+--FILE--
+<?php
+function test1(array $values) {
+    foreach ($values as $key => $value) {
+        return match (true) {
+            $key == "return key" => $key,
+            $key == "return value" => $value,
+            $key == "break" => break,
+            $key == "continue" => continue,
+            default => continue,
+        };
+    }
+    return "default return";
+}
+echo test1(['a', 'b', 'return key' => 'value']) . PHP_EOL;
+echo test1(['return value' => 'value', 'a', 'b']) . PHP_EOL;
+echo test1(['continue' => 'value', 'return value' => 'value']) . PHP_EOL;
+echo test1(['break' => 'value', 'return value' => 'value']) . PHP_EOL;
+echo test1([]) . PHP_EOL;
+
+echo '---' . PHP_EOL;
+
+function test2(array $values) {
+    $i = 0;
+    $recursionGuard = function()use(&$i) {return 10 > $i++;};
+    $next = reset($values);
+    while ($next != null) {
+        $recursionGuard() ?: return "recursion";
+
+        $next = match (true) {
+            $next == "return key" => return "key",
+            $next == "return value" => return "value",
+            $next == "break" => break,
+            $next == "continue" => continue,
+            default => next($values),
+        };
+    }
+    return $next ?? "default return";
+}
+var_dump(test2([]));
+var_dump(test2(['return key']));
+var_dump(test2(['return value']));
+var_dump(test2(['break']));
+var_dump(test2(['a', 'b', 'break']));
+var_dump(test2(['a', 'b', 'continue']));
+
+?>
+--EXPECT--
+return key
+value
+value
+default return
+default return
+---
+bool(false)
+string(3) "key"
+string(5) "value"
+string(5) "break"
+string(5) "break"
+string(9) "recursion"

tests/lang/early-return/memory_leaks.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Memory leaks
+--FILE--
+<?php
+class Foo {}
+
+function test() {
+    new Foo() + return;
+}
+
+test();
+
+?>
+--EXPECT--
+

tests/lang/loops/break_001.phpt

@@ -0,0 +1,39 @@
+--TEST--
+Early break
+--FILE--
+<?php
+// no break
+for($i = 5; $i >= 0; $i--) {
+  echo $i;
+}
+echo PHP_EOL;
+// old way break
+for($i = 5; $i >= 0; $i--) {
+    if ($i < 3) {
+        break;
+    }
+    echo $i;
+}
+echo PHP_EOL;
+// new way break
+for($i = 5; $i >= 0; $i--) {
+    $i < 3 ? break : null;
+    echo $i;
+}
+echo PHP_EOL;
+for($i = 5; $i >= 0; $i--) {
+    $i > 3 ?: break;
+    echo $i;
+}
+echo PHP_EOL;
+for($i = 5; $i >= 0; $i--) {
+    $var = $i ?: break;
+    echo $i;
+}
+?>
+--EXPECTF--
+543210
+543
+543
+54
+54321

tests/lang/loops/break_002_context.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Early break
+--FILE--
+<?php
+for($i = 5; $i >= 0; $i--) {
+    try {
+        echo (function(){ return $var = $i ?: break; })($i);
+    } catch (\Error $e) {
+        var_dump($e->getMessage());
+    }
+}
+?>
+--EXPECTF--
+Fatal error: 'break' not in the 'loop' or 'switch' context in %s on line %d