Prohibit pipe & arrow function combination that leads to confusing parse trees

Author: iluuu1994

Zend/tests/arrow_functions/gh7900.phpt

@@ -23,4 +23,4 @@ try {
 ?>
 --EXPECT--
 Here
-assert(fn(): never => 42 && false)
+assert((fn(): never => 42) && false)

Zend/tests/pipe_operator/mixed_callable_call.phpt

@@ -71,7 +71,7 @@ $res1 = 1
     |> [StaticTest::class, 'times17']
     |> new Times23()
     |> $times29
-    |> fn($x) => times2($x)
+    |> (fn($x) => times2($x))
 ;
 
 var_dump($res1);

Zend/tests/pipe_operator/prec_001.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Pipe precedence 001
+--FILE--
+<?php
+
+42
+    |> fn($x) => $x < 42
+    |> fn($x) => var_dump($x);
+
+?>
+--EXPECTF--
+Fatal error: Arrow functions on the right hand side of |> must be parenthesized in %s on line %d

Zend/tests/pipe_operator/prec_002.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Pipe precedence 002
+--FILE--
+<?php
+
+42
+    |> (fn($x) => $x < 42)
+    |> (fn($x) => var_dump($x)) ;
+
+?>
+--EXPECT--
+bool(false)

Zend/tests/pipe_operator/prec_003.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Pipe precedence 003
+--FILE--
+<?php
+
+null
+    |> fn() => print (new Exception)->getTraceAsString() . "\n\n"
+    |> fn() => print (new Exception)->getTraceAsString() . "\n\n";
+
+?>
+--EXPECTF--
+Fatal error: Arrow functions on the right hand side of |> must be parenthesized in %s on line %d

Zend/tests/pipe_operator/prec_004.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Pipe precedence 004
+--FILE--
+<?php
+
+null
+    |> (fn() => print (new Exception)->getTraceAsString() . "\n\n")
+    |> (fn() => print (new Exception)->getTraceAsString() . "\n\n");
+
+?>
+--EXPECTF--
+#0 %s(%d): {closure:%s:%d}(NULL)
+#1 {main}
+
+#0 %s(%d): {closure:%s:%d}(1)
+#1 {main}

Zend/tests/pipe_operator/prec_005.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Pipe precedence 005
+--FILE--
+<?php
+
+try {
+    assert(false && 1 |> (fn() => 2));
+} catch (AssertionError $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECT--
+assert(false && 1 |> (fn() => 2))

Zend/tests/pipe_operator/prec_006.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Pipe precedence 006
+--FILE--
+<?php
+
+$value = null;
+$value
+    |> fn ($x) => $x ?? throw new Exception('Value may not be null')
+    |> fn ($x) => var_dump($x);
+
+?>
+--EXPECTF--
+Fatal error: Arrow functions on the right hand side of |> must be parenthesized in %s on line %d

Zend/tests/pipe_operator/prec_007.phpt

@@ -0,0 +1,24 @@
+--TEST--
+Pipe precedence 007
+--FILE--
+<?php
+
+$value = 42;
+$value
+    |> (fn ($x) => $x ?? throw new Exception('Value may not be null'))
+    |> (fn ($x) => var_dump($x));
+
+$value = null;
+$value
+    |> (fn ($x) => $x ?? throw new Exception('Value may not be null'))
+    |> (fn ($x) => var_dump($x));
+
+?>
+--EXPECTF--
+int(42)
+
+Fatal error: Uncaught Exception: Value may not be null in %s:%d
+Stack trace:
+#0 %s(%d): {closure:%s:%d}(NULL)
+#1 {main}
+  thrown in %s on line %d

Zend/zend_ast.c

@@ -2070,6 +2070,9 @@ static ZEND_COLD void zend_ast_export_ex(smart_str *str, zend_ast *ast, int prio
 		case ZEND_AST_ARROW_FUNC:
 		case ZEND_AST_METHOD:
 			decl = (const zend_ast_decl *) ast;
+			if (decl->kind == ZEND_AST_ARROW_FUNC && (decl->attr & ZEND_PARENTHESIZED_ARROW_FUNC)) {
+				smart_str_appendc(str, '(');
+			}
 			if (decl->child[4]) {
 				bool newlines = !(ast->kind == ZEND_AST_CLOSURE || ast->kind == ZEND_AST_ARROW_FUNC);
 				zend_ast_export_attributes(str, decl->child[4], indent, newlines);
@@ -2113,6 +2116,9 @@ static ZEND_COLD void zend_ast_export_ex(smart_str *str, zend_ast *ast, int prio
 					}
 					smart_str_appends(str, " => ");
 					zend_ast_export_ex(str, body, 0, indent);
+					if (decl->attr & ZEND_PARENTHESIZED_ARROW_FUNC) {
+						smart_str_appendc(str, ')');
+					}
 					break;
 				}