Evaluate const expression cast at ct if possible

Related to GH-18264.

Author: iluuu1994

Diff for: Zend/Optimizer/zend_optimizer.c

@@ -82,31 +82,8 @@ zend_result zend_optimizer_eval_unary_op(zval *result, uint8_t opcode, zval *op1
 
 zend_result zend_optimizer_eval_cast(zval *result, uint32_t type, zval *op1) /* {{{ */
 {
-	switch (type) {
-		case IS_NULL:
-			ZVAL_NULL(result);
-			return SUCCESS;
-		case _IS_BOOL:
-			ZVAL_BOOL(result, zval_is_true(op1));
-			return SUCCESS;
-		case IS_LONG:
-			ZVAL_LONG(result, zval_get_long(op1));
-			return SUCCESS;
-		case IS_DOUBLE:
-			ZVAL_DOUBLE(result, zval_get_double(op1));
-			return SUCCESS;
-		case IS_STRING:
-			/* Conversion from double to string takes into account run-time
-			   'precision' setting and cannot be evaluated at compile-time */
-			if (Z_TYPE_P(op1) != IS_ARRAY && Z_TYPE_P(op1) != IS_DOUBLE) {
-				ZVAL_STR(result, zval_get_string(op1));
-				return SUCCESS;
-			}
-			break;
-		case IS_ARRAY:
-			ZVAL_COPY(result, op1);
-			convert_to_array(result);
-			return SUCCESS;
+	if (zend_try_ct_eval_cast(result, type, op1)) {
+		return SUCCESS;
 	}
 	return FAILURE;
 }

Diff for: Zend/tests/constexpr/constant_expressions_cast.phpt

@@ -18,6 +18,28 @@ const T9 = (array) new DateTime;
 const T10 = (int) new DateTime;
 
 var_dump(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10);
+
+const C_FLOAT = 0.3;
+const C_EMPTY_ARRAY = [];
+const C_ARRAY = ["a" => 1];
+const C_INT = 5;
+const C_EMPTY_STRING = "";
+const C_CALLABLE = var_dump(...);
+const C_USER_OBJECT = new X;
+const C_DATE_TIME = new DateTime;
+
+const T11 = (int) C_FLOAT;
+const T12 = (bool) C_FLOAT;
+const T13 = (string) C_EMPTY_ARRAY;
+const T14 = (object) C_ARRAY;
+const T15 = (float) C_INT;
+const T16 = (array) C_EMPTY_STRING;
+const T17 = (array) C_CALLABLE;
+const T18 = (array) C_USER_OBJECT;
+const T19 = (array) C_DATE_TIME;
+const T20 = (int) C_DATE_TIME;
+
+var_dump(T11, T12, T13, T14, T15, T16, T17, T18, T19, T20);
 ?>
 --EXPECTF--
 Warning: Array to string conversion in %s on line %d
@@ -62,3 +84,46 @@ array(3) {
   string(%d) "%s"
 }
 int(1)
+
+Warning: Array to string conversion in %s on line %d
+
+Warning: Object of class DateTime could not be converted to int in %s on line %d
+int(0)
+bool(true)
+string(5) "Array"
+object(stdClass)#%d (1) {
+  ["a"]=>
+  int(1)
+}
+float(5)
+array(1) {
+  [0]=>
+  string(0) ""
+}
+array(1) {
+  [0]=>
+  object(Closure)#%d (2) {
+    ["function"]=>
+    string(8) "var_dump"
+    ["parameter"]=>
+    array(2) {
+      ["$value"]=>
+      string(10) "<required>"
+      ["$values"]=>
+      string(10) "<optional>"
+    }
+  }
+}
+array(1) {
+  ["foo"]=>
+  int(3)
+}
+array(3) {
+  ["date"]=>
+  string(%d) "%s"
+  ["timezone_type"]=>
+  int(%d)
+  ["timezone"]=>
+  string(%d) "%s"
+}
+int(1)

Diff for: Zend/zend_compile.c

@@ -11842,6 +11842,34 @@ static zend_op *zend_delayed_compile_var(znode *result, zend_ast *ast, uint32_t
 }
 /* }}} */
 
+bool zend_try_ct_eval_cast(zval *result, uint32_t type, zval *op1)
+{
+	switch (type) {
+		case _IS_BOOL:
+			ZVAL_BOOL(result, zval_is_true(op1));
+			return true;
+		case IS_LONG:
+			ZVAL_LONG(result, zval_get_long(op1));
+			return true;
+		case IS_DOUBLE:
+			ZVAL_DOUBLE(result, zval_get_double(op1));
+			return true;
+		case IS_STRING:
+			/* Conversion from double to string takes into account run-time
+			   'precision' setting and cannot be evaluated at compile-time */
+			if (Z_TYPE_P(op1) != IS_ARRAY && Z_TYPE_P(op1) != IS_DOUBLE) {
+				ZVAL_STR(result, zval_get_string(op1));
+				return true;
+			}
+			break;
+		case IS_ARRAY:
+			ZVAL_COPY(result, op1);
+			convert_to_array(result);
+			return true;
+	}
+	return false;
+}
+
 static void zend_eval_const_expr(zend_ast **ast_ptr) /* {{{ */
 {
 	zend_ast *ast = *ast_ptr;
@@ -12129,6 +12157,10 @@ static void zend_eval_const_expr(zend_ast **ast_ptr) /* {{{ */
 			return;
 		case ZEND_AST_CAST:
 			zend_eval_const_expr(&ast->child[0]);
+			if (ast->child[0]->kind == ZEND_AST_ZVAL
+			 && zend_try_ct_eval_cast(&result, ast->attr, zend_ast_get_zval(ast->child[0]))) {
+				break;
+			}
 			return;
 		default:
 			return;

Diff for: Zend/zend_compile.h

@@ -1301,4 +1301,6 @@ ZEND_API bool zend_is_op_long_compatible(const zval *op);
 ZEND_API bool zend_binary_op_produces_error(uint32_t opcode, const zval *op1, const zval *op2);
 ZEND_API bool zend_unary_op_produces_error(uint32_t opcode, const zval *op);
 
+bool zend_try_ct_eval_cast(zval *result, uint32_t type, zval *op1);
+
 #endif /* ZEND_COMPILE_H */