Do not suppress diagnostics when a class list is passed to silence

Also fixes a bug where any return value from @<class> would be NULL

Author: Girgias

Zend/tests/silence_operator/emit_diagnostic_when_silence_class_list.phpt

@@ -0,0 +1,20 @@
+--TEST--
+Diagnostics should still be emitted if a class list is passed to @, userland
+--FILE--
+<?php
+
+function test() {
+    trigger_error('Diagnostic message', E_USER_NOTICE);
+    return true;
+}
+
+$var = @<Exception>test();
+
+var_dump($var);
+
+echo "Done\n";
+?>
+--EXPECTF--
+Notice: Diagnostic message in %s on line %d
+bool(true)
+Done

Zend/tests/silence_operator/emit_internal_diagnostic_when_silence_class_list.phpt

@@ -0,0 +1,20 @@
+--TEST--
+Diagnostics should still be emitted if a class list is passed to @, internal
+--FILE--
+<?php
+
+function test() {
+    $r = $a + 1;
+    return $r;
+}
+
+$var = @<Exception>test();
+
+var_dump($var);
+
+echo "Done\n";
+?>
+--EXPECTF--
+Warning: Undefined variable $a in %s on line %d
+int(1)
+Done

Zend/zend_compile.c

@@ -9332,6 +9332,7 @@ static void zend_compile_silence(znode *result, zend_ast *ast) /* {{{ */
 {
 	zend_ast *expr_ast = ast->child[0];
 	znode silence_node;
+	zend_op *silence_start_op;
 	zend_op *silence_catch_op;
 	uint32_t try_catch_offset;
 	uint32_t virtual_catch_op_num;
@@ -9341,7 +9342,7 @@ static void zend_compile_silence(znode *result, zend_ast *ast) /* {{{ */
 	try_catch_offset = zend_add_try_element(get_next_op_number());
 	CG(context).try_catch_offset = try_catch_offset;
 
-	zend_emit_op_tmp(&silence_node, ZEND_BEGIN_SILENCE, NULL, NULL);
+	silence_start_op = zend_emit_op_tmp(&silence_node, ZEND_BEGIN_SILENCE, NULL, NULL);
 
 	if (expr_ast->kind == ZEND_AST_VAR) {
 		/* For @$var we need to force a FETCH instruction, otherwise the CV access will
@@ -9368,7 +9369,8 @@ static void zend_compile_silence(znode *result, zend_ast *ast) /* {{{ */
 		zend_ast_list *classes = zend_ast_get_list(ast->child[1]);
 		uint32_t opnum_catch = (uint32_t)-1;
 
-		/* Inform SILENCE_CATCH opcode that there is an exception class list */
+		/* Inform SILENCE_START and SILENCE_CATCH opcode that there is an exception class list */
+		silence_start_op->extended_value = 1;
 		silence_catch_op->extended_value = 2;
 
 		ZEND_ASSERT(classes->children > 0 && "Should have at least one class");

Zend/zend_vm_def.h

@@ -7434,6 +7434,11 @@ ZEND_VM_HANDLER(57, ZEND_BEGIN_SILENCE, ANY, ANY)
 
 	ZVAL_LONG(EX_VAR(opline->result.var), EG(error_reporting));
 
+	/* Do not suppress diagnostics when a class list is passed to @ */
+	if (opline->extended_value == 1) {
+		ZEND_VM_NEXT_OPCODE();
+	}
+
 	if (!E_HAS_ONLY_FATAL_ERRORS(EG(error_reporting))) {
 		do {
 			/* Do not silence fatal errors */
@@ -7481,20 +7486,15 @@ ZEND_VM_HANDLER(203, ZEND_SILENCE_CATCH, ANY, ANY)
 
 	/* Came from class list virtual catch blocks */
 	if (opline->extended_value == 2) {
-		if (EG(exception) == NULL) {
-			/* Free object (needed to not leak memory on @new) */
-			if (Z_TYPE_P(EX_VAR(opline->result.var)) == IS_OBJECT) {
-				//OBJ_RELEASE(Z_OBJ_P(EX_VAR(opline->result.var)));
-			}
-
-			/* Set value to NULL */
-			if (opline->result_type & (IS_VAR | IS_TMP_VAR)) {
-				ZVAL_NULL(EX_VAR(opline->result.var));
-			}
-		} else {
+		if (EG(exception) != NULL) {
 			zend_rethrow_exception(execute_data);
 			HANDLE_EXCEPTION();
 		}
+		/* Result is UNDEF means an exception has been caught */
+		if (opline->result_type & (IS_VAR | IS_TMP_VAR)
+				&& Z_TYPE_P(EX_VAR(opline->result.var)) == IS_UNDEF) {
+			ZVAL_NULL(EX_VAR(opline->result.var));
+        }
 	} else if (EG(exception) && opline->extended_value != 2) {
 		ZEND_ASSERT(EG(exception)->ce);
 		/* Only suppress Exception or a subclass of, and NOT Error throwable errors */