patch library: syscall, os/exec

internal/lib/os/exec/exec.go

@@ -0,0 +1,22 @@
+/*
+ * 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 exec
+
+// llgo:skipall
+import (
+	_ "unsafe"
+)

internal/lib/os/exec/lp_plan9.go

@@ -0,0 +1,66 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package exec
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// ErrNotFound is the error resulting if a path search failed to find an executable file.
+var ErrNotFound = errors.New("executable file not found in $path")
+
+func findExecutable(file string) error {
+	d, err := os.Stat(file)
+	if err != nil {
+		return err
+	}
+	if m := d.Mode(); !m.IsDir() && m&0111 != 0 {
+		return nil
+	}
+	return fs.ErrPermission
+}
+
+// LookPath searches for an executable named file in the
+// directories named by the path environment variable.
+// If file begins with "/", "#", "./", or "../", it is tried
+// directly and the path is not consulted.
+// On success, the result is an absolute path.
+//
+// In older versions of Go, LookPath could return a path relative to the current directory.
+// As of Go 1.19, LookPath will instead return that path along with an error satisfying
+// errors.Is(err, ErrDot). See the package documentation for more details.
+func LookPath(file string) (string, error) {
+	// skip the path lookup for these prefixes
+	skip := []string{"/", "#", "./", "../"}
+
+	for _, p := range skip {
+		if strings.HasPrefix(file, p) {
+			err := findExecutable(file)
+			if err == nil {
+				return file, nil
+			}
+			return "", &Error{file, err}
+		}
+	}
+
+	path := os.Getenv("path")
+	for _, dir := range filepath.SplitList(path) {
+		path := filepath.Join(dir, file)
+		if err := findExecutable(path); err == nil {
+			if !filepath.IsAbs(path) {
+				if execerrdot.Value() != "0" {
+					return path, &Error{file, ErrDot}
+				}
+				execerrdot.IncNonDefault()
+			}
+			return path, nil
+		}
+	}
+	return "", &Error{file, ErrNotFound}
+}

internal/lib/os/exec/lp_unix.go

@@ -0,0 +1,82 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix
+
+package exec
+
+import (
+	"errors"
+)
+
+// ErrNotFound is the error resulting if a path search failed to find an executable file.
+var ErrNotFound = errors.New("executable file not found in $PATH")
+
+func findExecutable(file string) error {
+	/* TODO(xsw):
+	d, err := os.Stat(file)
+	if err != nil {
+		return err
+	}
+	m := d.Mode()
+	if m.IsDir() {
+		return syscall.EISDIR
+	}
+	err = unix.Eaccess(file, unix.X_OK)
+	// ENOSYS means Eaccess is not available or not implemented.
+	// EPERM can be returned by Linux containers employing seccomp.
+	// In both cases, fall back to checking the permission bits.
+	if err == nil || (err != syscall.ENOSYS && err != syscall.EPERM) {
+		return err
+	}
+	if m&0111 != 0 {
+		return nil
+	}
+	return fs.ErrPermission
+	*/
+	panic("todo: exec.findExecutable")
+}
+
+// LookPath searches for an executable named file in the
+// directories named by the PATH environment variable.
+// If file contains a slash, it is tried directly and the PATH is not consulted.
+// Otherwise, on success, the result is an absolute path.
+//
+// In older versions of Go, LookPath could return a path relative to the current directory.
+// As of Go 1.19, LookPath will instead return that path along with an error satisfying
+// errors.Is(err, ErrDot). See the package documentation for more details.
+func LookPath(file string) (string, error) {
+	/* TODO(xsw):
+	// NOTE(rsc): I wish we could use the Plan 9 behavior here
+	// (only bypass the path if file begins with / or ./ or ../)
+	// but that would not match all the Unix shells.
+
+	if strings.Contains(file, "/") {
+		err := findExecutable(file)
+		if err == nil {
+			return file, nil
+		}
+		return "", &Error{file, err}
+	}
+	path := os.Getenv("PATH")
+	for _, dir := range filepath.SplitList(path) {
+		if dir == "" {
+			// Unix shell semantics: path element "" means "."
+			dir = "."
+		}
+		path := filepath.Join(dir, file)
+		if err := findExecutable(path); err == nil {
+			if !filepath.IsAbs(path) {
+				if execerrdot.Value() != "0" {
+					return path, &Error{file, ErrDot}
+				}
+				execerrdot.IncNonDefault()
+			}
+			return path, nil
+		}
+	}
+	return "", &Error{file, ErrNotFound}
+	*/
+	panic("todo: exec.LookPath")
+}

internal/lib/os/exec/lp_wasm.go

@@ -0,0 +1,23 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build wasm
+
+package exec
+
+import (
+	"errors"
+)
+
+// ErrNotFound is the error resulting if a path search failed to find an executable file.
+var ErrNotFound = errors.New("executable file not found in $PATH")
+
+// LookPath searches for an executable named file in the
+// directories named by the PATH environment variable.
+// If file contains a slash, it is tried directly and the PATH is not consulted.
+// The result may be an absolute path or a path relative to the current directory.
+func LookPath(file string) (string, error) {
+	// Wasm can not execute processes, so act as if there are no executables at all.
+	return "", &Error{file, ErrNotFound}
+}

internal/lib/os/exec/lp_windows.go

@@ -0,0 +1,145 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package exec
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+)
+
+// ErrNotFound is the error resulting if a path search failed to find an executable file.
+var ErrNotFound = errors.New("executable file not found in %PATH%")
+
+func chkStat(file string) error {
+	d, err := os.Stat(file)
+	if err != nil {
+		return err
+	}
+	if d.IsDir() {
+		return fs.ErrPermission
+	}
+	return nil
+}
+
+func hasExt(file string) bool {
+	i := strings.LastIndex(file, ".")
+	if i < 0 {
+		return false
+	}
+	return strings.LastIndexAny(file, `:\/`) < i
+}
+
+func findExecutable(file string, exts []string) (string, error) {
+	if len(exts) == 0 {
+		return file, chkStat(file)
+	}
+	if hasExt(file) {
+		if chkStat(file) == nil {
+			return file, nil
+		}
+	}
+	for _, e := range exts {
+		if f := file + e; chkStat(f) == nil {
+			return f, nil
+		}
+	}
+	return "", fs.ErrNotExist
+}
+
+// LookPath searches for an executable named file in the
+// directories named by the PATH environment variable.
+// LookPath also uses PATHEXT environment variable to match
+// a suitable candidate.
+// If file contains a slash, it is tried directly and the PATH is not consulted.
+// Otherwise, on success, the result is an absolute path.
+//
+// In older versions of Go, LookPath could return a path relative to the current directory.
+// As of Go 1.19, LookPath will instead return that path along with an error satisfying
+// errors.Is(err, ErrDot). See the package documentation for more details.
+func LookPath(file string) (string, error) {
+	var exts []string
+	x := os.Getenv(`PATHEXT`)
+	if x != "" {
+		for _, e := range strings.Split(strings.ToLower(x), `;`) {
+			if e == "" {
+				continue
+			}
+			if e[0] != '.' {
+				e = "." + e
+			}
+			exts = append(exts, e)
+		}
+	} else {
+		exts = []string{".com", ".exe", ".bat", ".cmd"}
+	}
+
+	if strings.ContainsAny(file, `:\/`) {
+		f, err := findExecutable(file, exts)
+		if err == nil {
+			return f, nil
+		}
+		return "", &Error{file, err}
+	}
+
+	// On Windows, creating the NoDefaultCurrentDirectoryInExePath
+	// environment variable (with any value or no value!) signals that
+	// path lookups should skip the current directory.
+	// In theory we are supposed to call NeedCurrentDirectoryForExePathW
+	// "as the registry location of this environment variable can change"
+	// but that seems exceedingly unlikely: it would break all users who
+	// have configured their environment this way!
+	// https://docs.microsoft.com/en-us/windows/win32/api/processenv/nf-processenv-needcurrentdirectoryforexepathw
+	// See also go.dev/issue/43947.
+	var (
+		dotf   string
+		dotErr error
+	)
+	if _, found := syscall.Getenv("NoDefaultCurrentDirectoryInExePath"); !found {
+		if f, err := findExecutable(filepath.Join(".", file), exts); err == nil {
+			if execerrdot.Value() == "0" {
+				execerrdot.IncNonDefault()
+				return f, nil
+			}
+			dotf, dotErr = f, &Error{file, ErrDot}
+		}
+	}
+
+	path := os.Getenv("path")
+	for _, dir := range filepath.SplitList(path) {
+		if f, err := findExecutable(filepath.Join(dir, file), exts); err == nil {
+			if dotErr != nil {
+				// https://go.dev/issue/53536: if we resolved a relative path implicitly,
+				// and it is the same executable that would be resolved from the explicit %PATH%,
+				// prefer the explicit name for the executable (and, likely, no error) instead
+				// of the equivalent implicit name with ErrDot.
+				//
+				// Otherwise, return the ErrDot for the implicit path as soon as we find
+				// out that the explicit one doesn't match.
+				dotfi, dotfiErr := os.Lstat(dotf)
+				fi, fiErr := os.Lstat(f)
+				if dotfiErr != nil || fiErr != nil || !os.SameFile(dotfi, fi) {
+					return dotf, dotErr
+				}
+			}
+
+			if !filepath.IsAbs(f) {
+				if execerrdot.Value() != "0" {
+					return f, &Error{file, ErrDot}
+				}
+				execerrdot.IncNonDefault()
+			}
+			return f, nil
+		}
+	}
+
+	if dotErr != nil {
+		return dotf, dotErr
+	}
+	return "", &Error{file, ErrNotFound}
+}