Support FLAGS_COALESCE on AST_ASSIGN_OP (??=)

Author: TysonAndre

README.md

@@ -297,6 +297,7 @@ ast\flags\BINARY_MOD
 ast\flags\BINARY_POW
 ast\flags\BINARY_SHIFT_LEFT
 ast\flags\BINARY_SHIFT_RIGHT
+ast\flags\BINARY_COALESCE
 
 // Used by ast\AST_BINARY_OP (exclusive)
 ast\flags\BINARY_BOOL_AND
@@ -311,7 +312,6 @@ ast\flags\BINARY_IS_SMALLER_OR_EQUAL
 ast\flags\BINARY_IS_GREATER
 ast\flags\BINARY_IS_GREATER_OR_EQUAL
 ast\flags\BINARY_SPACESHIP
-ast\flags\BINARY_COALESCE
 
 // Used by ast\AST_MAGIC_CONST (exclusive)
 ast\flags\MAGIC_LINE

ast.c

@@ -134,7 +134,8 @@ static const char *unary_op_flags[] = {
 	AST_FLAG(BINARY_MOD), \
 	AST_FLAG(BINARY_POW), \
 	AST_FLAG(BINARY_SHIFT_LEFT), \
-	AST_FLAG(BINARY_SHIFT_RIGHT) \
+	AST_FLAG(BINARY_SHIFT_RIGHT), \
+	AST_FLAG(BINARY_COALESCE) \
 
 static const char *binary_op_flags[] = {
 	AST_SHARED_BINARY_OP_FLAGS,
@@ -150,7 +151,6 @@ static const char *binary_op_flags[] = {
 	AST_FLAG(BINARY_IS_GREATER),
 	AST_FLAG(BINARY_IS_GREATER_OR_EQUAL),
 	AST_FLAG(BINARY_SPACESHIP),
-	AST_FLAG(BINARY_COALESCE),
 	NULL
 };
 
@@ -720,6 +720,10 @@ static void ast_to_zval(zval *zv, zend_ast *ast, ast_state_info_t *state) {
 				return;
 			}
 			break;
+		case ZEND_AST_ASSIGN_COALESCE:
+			ast->kind = ZEND_AST_ASSIGN_OP;
+			ast->attr = AST_BINARY_COALESCE;
+			break;
 #endif
 	}
 

package.xml

@@ -25,6 +25,7 @@
  <notes>
 - Fix a segfault in PHP 7.4-dev after typed properties support was added.
 - Add AST version 70 (experimental): This adds AST_PROP_GROUP with type information for property groups.
+- Support BINARY_COALESCE as a flag of AST_ASSIGN_OP for the `??=` operator in PHP 7.4-dev.
  </notes>
  <contents>
   <dir name="/">

tests/metadata.phpt

@@ -79,8 +79,8 @@ AST_CALL: []
 AST_CLASS_CONST: []
 AST_ASSIGN: []
 AST_ASSIGN_REF: []
-AST_ASSIGN_OP: [BINARY_BITWISE_OR, BINARY_BITWISE_AND, BINARY_BITWISE_XOR, BINARY_CONCAT, BINARY_ADD, BINARY_SUB, BINARY_MUL, BINARY_DIV, BINARY_MOD, BINARY_POW, BINARY_SHIFT_LEFT, BINARY_SHIFT_RIGHT]
-AST_BINARY_OP: [BINARY_BITWISE_OR, BINARY_BITWISE_AND, BINARY_BITWISE_XOR, BINARY_CONCAT, BINARY_ADD, BINARY_SUB, BINARY_MUL, BINARY_DIV, BINARY_MOD, BINARY_POW, BINARY_SHIFT_LEFT, BINARY_SHIFT_RIGHT, BINARY_BOOL_AND, BINARY_BOOL_OR, BINARY_BOOL_XOR, BINARY_IS_IDENTICAL, BINARY_IS_NOT_IDENTICAL, BINARY_IS_EQUAL, BINARY_IS_NOT_EQUAL, BINARY_IS_SMALLER, BINARY_IS_SMALLER_OR_EQUAL, BINARY_IS_GREATER, BINARY_IS_GREATER_OR_EQUAL, BINARY_SPACESHIP, BINARY_COALESCE]
+AST_ASSIGN_OP: [BINARY_BITWISE_OR, BINARY_BITWISE_AND, BINARY_BITWISE_XOR, BINARY_CONCAT, BINARY_ADD, BINARY_SUB, BINARY_MUL, BINARY_DIV, BINARY_MOD, BINARY_POW, BINARY_SHIFT_LEFT, BINARY_SHIFT_RIGHT, BINARY_COALESCE]
+AST_BINARY_OP: [BINARY_BITWISE_OR, BINARY_BITWISE_AND, BINARY_BITWISE_XOR, BINARY_CONCAT, BINARY_ADD, BINARY_SUB, BINARY_MUL, BINARY_DIV, BINARY_MOD, BINARY_POW, BINARY_SHIFT_LEFT, BINARY_SHIFT_RIGHT, BINARY_COALESCE, BINARY_BOOL_AND, BINARY_BOOL_OR, BINARY_BOOL_XOR, BINARY_IS_IDENTICAL, BINARY_IS_NOT_IDENTICAL, BINARY_IS_EQUAL, BINARY_IS_NOT_EQUAL, BINARY_IS_SMALLER, BINARY_IS_SMALLER_OR_EQUAL, BINARY_IS_GREATER, BINARY_IS_GREATER_OR_EQUAL, BINARY_SPACESHIP]
 AST_ARRAY_ELEM: [ARRAY_ELEM_REF]
 AST_NEW: []
 AST_INSTANCEOF: []

tests/php74_ast_assign_coalesce.phpt

@@ -0,0 +1,39 @@
+--TEST--
+'??=' operator in PHP 7.4
+--SKIPIF--
+<?php if (PHP_VERSION_ID < 70400) die('skip PHP >= 7.4 only'); ?>
+--FILE--
+<?php
+
+require __DIR__ . '/../util.php';
+
+$code = <<<'PHP'
+<?php
+$x ??= 2;
+Foo::$prop['offset'] ??= $other ??= 'value';
+PHP;
+
+$node = ast\parse_code($code, $version=70);
+echo ast_dump($node), "\n";
+?>
+--EXPECTF--
+AST_STMT_LIST
+    0: AST_ASSIGN_OP
+        flags: BINARY_COALESCE (%d)
+        var: AST_VAR
+            name: "x"
+        expr: 2
+    1: AST_ASSIGN_OP
+        flags: BINARY_COALESCE (%d)
+        var: AST_DIM
+            expr: AST_STATIC_PROP
+                class: AST_NAME
+                    flags: NAME_NOT_FQ (%d)
+                    name: "Foo"
+                prop: "prop"
+            dim: "offset"
+        expr: AST_ASSIGN_OP
+            flags: BINARY_COALESCE (%d)
+            var: AST_VAR
+                name: "other"
+            expr: "value"