Fix empty match expressions and match expressions with default case only in PHP 7

Author: thekid

ChangeLog.md

@@ -3,6 +3,15 @@ XP Compiler ChangeLog
 
 ## ?.?.? / ????-??-??
 
+## 9.3.2 / 2024-11-02
+
+* Fixed empty match expressions and match expressions with default
+  case only in PHP 7
+  (@thekid)
+* Added tests verifying closures are supported in constant expressions
+  https://wiki.php.net/rfc/closures_in_const_expr
+  (@thekid)
+
 ## 9.3.1 / 2024-10-05
 
 * Fixed `private(set)` not being implicitely marked as *final*, see

src/main/php/lang/ast/emit/MatchAsTernaries.class.php

@@ -30,9 +30,12 @@ protected function emitMatch($result, $match) {
       }
     }
 
+    // Match without cases => create something that will never match
+    $b || $result->out->write('===NAN?:');
+
     // Emit IIFE for raising an error until we have throw expressions
     if (null === $match->default) {
-      $result->out->write('function() use('.$t.') { throw new \\Error("Unhandled match value of type ".gettype('.$t.')); })(');
+      $result->out->write('(function() use('.$t.') { throw new \\Error("Unhandled match value of type ".gettype('.$t.')); })()');
     } else {
       $this->emitAsExpression($result, $match->default);
     }

src/test/php/lang/ast/unittest/emit/ControlStructuresTest.class.php

@@ -86,6 +86,19 @@ public function run($arg) {
     Assert::equals($expected, $r);
   }
 
+  #[Test]
+  public function match_with_default_only() {
+    $r= $this->run('class %T {
+      public function run() {
+        return match (true) {
+          default => "Test",
+        };
+      }
+    }');
+
+    Assert::equals('Test', $r);
+  }
+
   #[Test, Values([[200, 'OK'], [302, 'Redirect'], [404, 'Error #404']])]
   public function match_with_multiple_cases($input, $expected) {
     $r= $this->run('class %T {
@@ -154,6 +167,17 @@ public function run($arg) {
     Assert::equals('10+ items', $r);
   }
 
+  #[Test, Expect(class: Throwable::class, message: '/Unhandled match (value of type .+|case .+)/')]
+  public function empty_match() {
+    $r= $this->run('class %T {
+      public function run() {
+        return match (true) { };
+      }
+    }');
+
+    Assert::equals('Test', $r);
+  }
+
   #[Test, Expect(class: Throwable::class, message: '/Unhandled match (value of type .+|case .+)/')]
   public function unhandled_match() {
     $this->run('class %T {