Wrap pipe LHS in a QM_ASSIGN opcode to implicitly block references.

Author: Crell

Zend/tests/pipe_operator/call_by_ref.phpt

@@ -1,5 +1,5 @@
 --TEST--
-Pipe operator accepts by-reference functions
+Pipe operator rejects by-reference functions.
 --FILE--
 <?php
 
@@ -8,12 +8,30 @@ function _modify(int &$a): string {
     return "foo";
 }
 
-$a = 5;
-$res1 = $a |> '_modify';
+function _append(array &$a): string {
+    $a['bar'] = 'beep';
+}
+
+// Simple variables
+try {
+    $a = 5;
+    $res1 = $a |> _modify(...);
+    var_dump($res1);
+} catch (\Error $e) {
+  print $e->getMessage() . PHP_EOL;
+}
+
+// Complex variables.
+try {
+    $a = ['foo' => 'beep'];
+    $res2 = $a |> _append(...);
+    var_dump($res2);
+} catch (\Error $e) {
+  print $e->getMessage() . PHP_EOL;
+}
+
 
-var_dump($res1);
-var_dump($a);
 ?>
---EXPECT--
-string(3) "foo"
-int(6)
+--EXPECTF--
+_modify(): Argument #1 ($a) could not be passed by reference
+_append(): Argument #1 ($a) could not be passed by reference

Zend/zend_compile.c

@@ -6412,6 +6412,32 @@ static bool can_match_use_jumptable(zend_ast_list *arms) {
 	return 1;
 }
 
+static void zend_compile_pipe(znode *result, zend_ast *ast)
+{
+	zend_ast *operand_ast = ast->child[0];
+	zend_ast *callable_ast = ast->child[1];
+
+	znode operand_result;
+	zend_compile_expr(&operand_result, operand_ast);
+	znode wrapped_operand_result;
+	zend_emit_op_tmp(&wrapped_operand_result, ZEND_QM_ASSIGN, &operand_result, NULL);
+
+	/* Turn $foo |> bar(...) into bar($foo). */
+	if (callable_ast->kind == ZEND_AST_CALL
+	    && callable_ast->child[1]->kind == ZEND_AST_CALLABLE_CONVERT) {
+		callable_ast = callable_ast->child[0];
+	}
+
+	znode callable_result;
+	zend_compile_expr(&callable_result, callable_ast);
+
+	zend_ast *fcall_ast = zend_ast_create(ZEND_AST_CALL,
+	                                      zend_ast_create_znode(&callable_result),
+	                                      zend_ast_create_list(1, ZEND_AST_ARG_LIST, zend_ast_create_znode(&wrapped_operand_result)));
+
+	zend_compile_expr(result, fcall_ast);
+}
+
 static void zend_compile_match(znode *result, zend_ast *ast)
 {
 	zend_ast *expr_ast = ast->child[0];
@@ -6598,30 +6624,6 @@ static void zend_compile_match(znode *result, zend_ast *ast)
 	efree(jmp_end_opnums);
 }
 
-static void zend_compile_pipe(znode *result, zend_ast *ast)
-{
-	zend_ast *operand_ast = ast->child[0];
-	zend_ast *callable_ast = ast->child[1];
-
-	znode operand_result;
-	zend_compile_expr(&operand_result, operand_ast);
-
-	/* Turn $foo |> bar(...) into bar($foo). */
-	if (callable_ast->kind == ZEND_AST_CALL
-	 && callable_ast->child[1]->kind == ZEND_AST_CALLABLE_CONVERT) {
-		callable_ast = callable_ast->child[0];
-	 }
-
-	znode callable_result;
-	zend_compile_expr(&callable_result, callable_ast);
-
-	zend_ast *fcall_ast = zend_ast_create(ZEND_AST_CALL,
-		zend_ast_create_znode(&callable_result),
-		zend_ast_create_list(1, ZEND_AST_ARG_LIST, zend_ast_create_znode(&operand_result)));
-
-	zend_compile_expr(result, fcall_ast);
-}
-
 static void zend_compile_try(zend_ast *ast) /* {{{ */
 {
 	zend_ast *try_ast = ast->child[0];