[RFC] Make throw statement an expression

Zend/tests/throw/001.phpt

@@ -0,0 +1,175 @@
+--TEST--
+throw expression
+--FILE--
+<?php
+
+try {
+    $result = true && throw new Exception("true && throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = false && throw new Exception("false && throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = true and throw new Exception("true and throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = false and throw new Exception("false and throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = true || throw new Exception("true || throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = false || throw new Exception("false || throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = true or throw new Exception("true or throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = false or throw new Exception("false or throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = null ?? throw new Exception("null ?? throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = "foo" ?? throw new Exception('"foo" ?? throw');
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = null ?: throw new Exception("null ?: throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = "foo" ?: throw new Exception('"foo" ?: throw');
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $callable = fn() => throw new Exception("fn() => throw");
+    var_dump("not yet");
+    $callable();
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+$result = "bar";
+try {
+    $result = throw new Exception();
+} catch (Exception $e) {}
+var_dump($result);
+
+try {
+    var_dump(
+        throw new Exception("exception 1"),
+        throw new Exception("exception 2")
+    );
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = true ? true : throw new Exception("true ? true : throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    $result = false ? true : throw new Exception("false ? true : throw");
+    var_dump($result);
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    throw new Exception() + 1;
+} catch (Throwable $e) {
+    var_dump($e->getMessage());
+}
+
+try {
+    throw $exception = new Exception('throw $exception = new Exception();');
+} catch (Exception $e) {}
+var_dump($exception->getMessage());
+
+try {
+    $exception = null;
+    throw $exception ??= new Exception('throw $exception ??= new Exception();');
+} catch (Exception $e) {}
+var_dump($exception->getMessage());
+
+try {
+    throw null ?? new Exception('throw null ?? new Exception();');
+} catch (Exception $e) {
+    var_dump($e->getMessage());
+}
+
+?>
+--EXPECTF--
+string(13) "true && throw"
+bool(false)
+string(14) "true and throw"
+bool(false)
+bool(true)
+string(14) "false || throw"
+bool(true)
+string(14) "false or throw"
+string(13) "null ?? throw"
+string(3) "foo"
+string(13) "null ?: throw"
+string(3) "foo"
+string(7) "not yet"
+string(13) "fn() => throw"
+string(3) "bar"
+string(11) "exception 1"
+bool(true)
+string(20) "false ? true : throw"
+
+Notice: Object of class Exception could not be converted to number in %s on line %d
+string(22) "Can only throw objects"
+string(35) "throw $exception = new Exception();"
+string(37) "throw $exception ??= new Exception();"
+string(30) "throw null ?? new Exception();"

Zend/tests/throw/002.phpt

@@ -0,0 +1,127 @@
+--TEST--
+Test throw with various expressions
+--FILE--
+<?php
+
+class Foo {
+    public function createNotFoundException() {
+        return new Exception('Not found');
+    }
+
+    public function throwException() {
+        throw $this->createNotFoundException();
+    }
+
+    public static function staticCreateNotFoundException() {
+        return new Exception('Static not found');
+    }
+
+    public static function staticThrowException() {
+        throw static::staticCreateNotFoundException();
+    }
+}
+
+try {
+    (new Foo())->throwException();
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    Foo::staticThrowException();
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    throw true ? new Exception('Ternary true 1') : new Exception('Ternary true 2');
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    throw false ? new Exception('Ternary false 1') : new Exception('Ternary false 2');
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    $exception1 = new Exception('Coalesce non-null 1');
+    $exception2 = new Exception('Coalesce non-null 2');
+    throw $exception1 ?? $exception2;
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    $exception1 = null;
+    $exception2 = new Exception('Coalesce null 2');
+    throw $exception1 ?? $exception2;
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    throw $exception = new Exception('Assignment');
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    $exception = null;
+    throw $exception ??= new Exception('Coalesce assignment null');
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    $exception = new Exception('Coalesce assignment non-null 1');
+    throw $exception ??= new Exception('Coalesce assignment non-null 2');
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+$andConditionalTest = function ($condition1, $condition2) {
+    throw $condition1 && $condition2
+        ? new Exception('And in conditional 1')
+        : new Exception('And in conditional 2');
+};
+
+try {
+    $andConditionalTest(false, false);
+} catch(Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    $andConditionalTest(false, true);
+} catch (Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    $andConditionalTest(true, false);
+} catch (Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+try {
+    $andConditionalTest(true, true);
+} catch (Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+--EXPECT--
+Not found
+Static not found
+Ternary true 1
+Ternary false 2
+Coalesce non-null 1
+Coalesce null 2
+Assignment
+Coalesce assignment null
+Coalesce assignment non-null 1
+And in conditional 2
+And in conditional 2
+And in conditional 2
+And in conditional 1

Zend/zend_compile.c

@@ -4557,14 +4557,17 @@ void zend_compile_echo(zend_ast *ast) /* {{{ */
 }
 /* }}} */
 
-void zend_compile_throw(zend_ast *ast) /* {{{ */
+void zend_compile_throw(znode *result, zend_ast *ast) /* {{{ */
 {
 	zend_ast *expr_ast = ast->child[0];
 
 	znode expr_node;
 	zend_compile_expr(&expr_node, expr_ast);
 
 	zend_emit_op(NULL, ZEND_THROW, &expr_node, NULL);
+
+	result->op_type = IS_CONST;
+	ZVAL_BOOL(&result->u.constant, 1);
 }
 /* }}} */
 
@@ -8741,9 +8744,6 @@ void zend_compile_stmt(zend_ast *ast) /* {{{ */
 		case ZEND_AST_ECHO:
 			zend_compile_echo(ast);
 			break;
-		case ZEND_AST_THROW:
-			zend_compile_throw(ast);
-			break;
 		case ZEND_AST_BREAK:
 		case ZEND_AST_CONTINUE:
 			zend_compile_break_continue(ast);
@@ -8953,6 +8953,9 @@ void zend_compile_expr(znode *result, zend_ast *ast) /* {{{ */
 		case ZEND_AST_ARROW_FUNC:
 			zend_compile_func_decl(result, ast, 0);
 			return;
+		case ZEND_AST_THROW:
+			zend_compile_throw(result, ast);
+			break;
 		default:
 			ZEND_ASSERT(0 /* not supported */);
 	}

Zend/zend_language_parser.y

@@ -51,6 +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 PREC_ARROW_FUNCTION
 %precedence T_INCLUDE T_INCLUDE_ONCE T_REQUIRE T_REQUIRE_ONCE
 %left T_LOGICAL_OR
@@ -457,7 +458,6 @@ statement:
 	|	';'	/* empty statement */ { $$ = NULL; }
 	|	T_TRY '{' inner_statement_list '}' catch_list finally_statement
 			{ $$ = zend_ast_create(ZEND_AST_TRY, $3, $5, $6); }
-	|	T_THROW expr ';' { $$ = zend_ast_create(ZEND_AST_THROW, $2); }
 	|	T_GOTO T_STRING ';' { $$ = zend_ast_create(ZEND_AST_GOTO, $2); }
 	|	T_STRING ':' { $$ = zend_ast_create(ZEND_AST_LABEL, $1); }
 ;
@@ -1019,6 +1019,7 @@ expr:
 	|	T_YIELD expr { $$ = 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; }
 	|	T_STATIC inline_function { $$ = $2; ((zend_ast_decl *) $$)->flags |= ZEND_ACC_STATIC; }
 ;