Add ast\flags\PARENTHESIZED_CONDITIONAL for php 7.4

This will make it easier for static analyzers to warn about the lack of
parenthesis, to format code from ASTs, etc.

Author: TysonAndre

README.md

@@ -345,6 +345,9 @@ ast\flags\ARRAY_ELEM_REF
 
 // Used by ast\AST_DIM (combinable), since PHP 7.4
 ast\flags\DIM_ALTERNATIVE_SYNTAX
+
+// Used by ast\AST_CONDITIONAL (combinable), since PHP 7.4
+ast\flags\PARENTHESIZED_CONDITIONAL
 ```
 
 AST node kinds

ast.c

@@ -58,6 +58,7 @@
 
 #if PHP_VERSION_ID < 70400
 # define ZEND_DIM_ALTERNATIVE_SYNTAX (1<<1)
+# define ZEND_PARENTHESIZED_CONDITIONAL 1
 #endif
 
 /* This contains state of the ast Node creator. */
@@ -242,6 +243,12 @@ static const char *dim_flags[] = {
 	NULL
 };
 
+// Flags of AST_CONDITIONAL are marked as combinable in case any other flags get added in the future.
+static const char *conditional_flags[] = {
+	AST_FLAG(PARENTHESIZED_CONDITIONAL),
+	NULL
+};
+
 static const ast_flag_info flag_info[] = {
 	{ AST_NAME, 0, name_flags },
 	{ ZEND_AST_CLASS, 0, class_flags },
@@ -268,6 +275,7 @@ static const ast_flag_info flag_info[] = {
 	{ ZEND_AST_CLASS_CONST_DECL, 1, visibility_flags },
 	{ ZEND_AST_TRAIT_ALIAS, 1, modifier_flags },
 	{ ZEND_AST_DIM, 1, dim_flags },
+	{ ZEND_AST_CONDITIONAL, 1, conditional_flags },
 };
 
 static inline void ast_update_property(zval *object, zend_string *name, zval *value, void **cache_slot) {
@@ -330,7 +338,7 @@ static inline zend_bool ast_kind_uses_attr(zend_ast_kind kind) {
 		|| kind == ZEND_AST_PROP_GROUP
 		|| kind == ZEND_AST_GROUP_USE || kind == ZEND_AST_USE_ELEM
 		|| kind == AST_NAME || kind == AST_CLOSURE_VAR || kind == ZEND_AST_CLASS_CONST_DECL
-		|| kind == ZEND_AST_ARRAY || kind == ZEND_AST_DIM;
+		|| kind == ZEND_AST_ARRAY || kind == ZEND_AST_DIM || kind == ZEND_AST_CONDITIONAL;
 }
 
 static inline zend_bool ast_kind_is_decl(zend_ast_kind kind) {
@@ -1338,6 +1346,8 @@ PHP_MINIT_FUNCTION(ast) {
 
 	ast_register_flag_constant("DIM_ALTERNATIVE_SYNTAX", ZEND_DIM_ALTERNATIVE_SYNTAX);
 
+	ast_register_flag_constant("PARENTHESIZED_CONDITIONAL", ZEND_PARENTHESIZED_CONDITIONAL);
+
 	INIT_CLASS_ENTRY(tmp_ce, "ast\\Node", ast_node_functions);
 	ast_node_ce = zend_register_internal_class(&tmp_ce);
 	ast_declare_property(ast_node_ce, AST_STR(str_kind), &zv_null);

package.xml

@@ -25,6 +25,7 @@
  <notes>
 - Fix build error in php 7.4.0alpha3.
 - Add `DIM_ALTERNATIVE_SYNTAX` as a flag of `AST_DIM` for `$x{'offset'}` (for php 7.4+)
+- Add `PARENTHESIZED_CONDITIONAL` as a flag of `AST_CONDITIONAL` for `($a ? $b : $c)` (for php 7.4+)
 - Bugfix: Make `ast\kind_uses_flags(ast\AST_ARROW_FUNC)` true in php 7.3 and lower.
  </notes>
  <contents>
@@ -85,6 +86,7 @@
       <file name="php74_ast_assign_coalesce.phpt" role="test" />
       <file name="php74_dim_alternative_syntax.phpt" role="test" />
       <file name="php74_ordinary_class.phpt" role="test" />
+      <file name="php74_parenthesized_conditional.phpt" role="test" />
       <file name="php74_type_hints.phpt" role="test" />
       <file name="prop_doc_comments.phpt" role="test" />
       <file name="short_arrow_function.phpt" role="test" />

tests/metadata.phpt

@@ -112,7 +112,7 @@ AST_TRAIT_ALIAS: (combinable) [MODIFIER_PUBLIC, MODIFIER_PROTECTED, MODIFIER_PRI
 AST_GROUP_USE: [USE_NORMAL, USE_FUNCTION, USE_CONST]
 AST_METHOD_CALL: []
 AST_STATIC_CALL: []
-AST_CONDITIONAL: []
+AST_CONDITIONAL: (combinable) [PARENTHESIZED_CONDITIONAL]
 AST_TRY: []
 AST_CATCH: []
 AST_PARAM: (combinable) [PARAM_REF, PARAM_VARIADIC]

tests/php74_parenthesized_conditional.phpt

@@ -0,0 +1,50 @@
+--TEST--
+parenthesized conditionals 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
+return $a ? $b : $c ? $d : $e;
+return $a ? $b : ($c ? $d : $e);
+PHP;
+
+$node = ast\parse_code($code, $version=70);
+echo ast_dump($node), "\n";
+?>
+--EXPECT--
+AST_STMT_LIST
+    0: AST_RETURN
+        expr: AST_CONDITIONAL
+            flags: 0
+            cond: AST_CONDITIONAL
+                flags: 0
+                cond: AST_VAR
+                    name: "a"
+                true: AST_VAR
+                    name: "b"
+                false: AST_VAR
+                    name: "c"
+            true: AST_VAR
+                name: "d"
+            false: AST_VAR
+                name: "e"
+    1: AST_RETURN
+        expr: AST_CONDITIONAL
+            flags: 0
+            cond: AST_VAR
+                name: "a"
+            true: AST_VAR
+                name: "b"
+            false: AST_CONDITIONAL
+                flags: PARENTHESIZED_CONDITIONAL (1)
+                cond: AST_VAR
+                    name: "c"
+                true: AST_VAR
+                    name: "d"
+                false: AST_VAR
+                    name: "e"