patch library: syscall, os/exec

internal/lib/_errors/errors.go

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package errors
+
+// llgo:skipall
+import (
+	_ "unsafe"
+)
+
+// Unwrap returns the result of calling the Unwrap method on err, if err's
+// type contains an Unwrap method returning error.
+// Otherwise, Unwrap returns nil.
+//
+// Unwrap only calls a method of the form "Unwrap() error".
+// In particular Unwrap does not unwrap errors returned by [Join].
+func Unwrap(err error) error {
+	u, ok := err.(interface {
+		Unwrap() error
+	})
+	if !ok {
+		return nil
+	}
+	return u.Unwrap()
+}
+
+// New returns an error that formats as the given text.
+// Each call to New returns a distinct error value even if the text is identical.
+func New(text string) error {
+	return &errorString{text}
+}
+
+// errorString is a trivial implementation of error.
+type errorString struct {
+	s string
+}
+
+func (e *errorString) Error() string {
+	return e.s
+}
+
+// ErrUnsupported indicates that a requested operation cannot be performed,
+// because it is unsupported. For example, a call to [os.Link] when using a
+// file system that does not support hard links.
+//
+// Functions and methods should not return this error but should instead
+// return an error including appropriate context that satisfies
+//
+//	errors.Is(err, errors.ErrUnsupported)
+//
+// either by directly wrapping ErrUnsupported or by implementing an Is method.
+//
+// Functions and methods should document the cases in which an error
+// wrapping this will be returned.
+var ErrUnsupported = New("unsupported operation")