Fixed dependency file parsing on Windows

go.mod

@@ -39,6 +39,7 @@ require (
 	go.bug.st/f v0.4.0
 	go.bug.st/relaxed-semver v0.12.0
 	go.bug.st/testifyjson v1.2.0
+	golang.org/x/sys v0.26.0
 	golang.org/x/term v0.25.0
 	golang.org/x/text v0.19.0
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20240814211410-ddb44dafa142
@@ -100,7 +101,6 @@ require (
 	golang.org/x/mod v0.18.0 // indirect
 	golang.org/x/net v0.28.0 // indirect
 	golang.org/x/sync v0.8.0 // indirect
-	golang.org/x/sys v0.26.0 // indirect
 	golang.org/x/tools v0.22.0 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/warnings.v0 v0.1.2 // indirect

internal/arduino/builder/internal/utils/ansi_others.go

@@ -0,0 +1,27 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2024 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to [email protected].
+
+//go:build !windows
+
+package utils
+
+import (
+	"errors"
+)
+
+// placeholder for non-Windows machines
+func convertAnsiBytesToString([]byte) (string, error) {
+	return "", errors.New("unimplemented")
+}

internal/arduino/builder/internal/utils/ansi_windows.go

@@ -0,0 +1,33 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2024 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to [email protected].
+
+package utils
+
+import (
+	"golang.org/x/sys/windows"
+)
+
+func convertAnsiBytesToString(data []byte) (string, error) {
+	dataSize := int32(len(data))
+	size, err := windows.MultiByteToWideChar(windows.GetACP(), 0, &data[0], dataSize, nil, 0)
+	if err != nil {
+		return "", err
+	}
+	utf16 := make([]uint16, size)
+	if _, err := windows.MultiByteToWideChar(windows.GetACP(), 0, &data[0], dataSize, &utf16[0], size); err != nil {
+		return "", err
+	}
+	return windows.UTF16ToString(utf16), nil
+}

internal/arduino/builder/internal/utils/utils.go

@@ -17,6 +17,7 @@ package utils
 
 import (
 	"os"
+	"runtime"
 	"strings"
 	"unicode"
 
@@ -74,63 +75,79 @@ func ObjFileIsUpToDate(sourceFile, objectFile, dependencyFile *paths.Path) (bool
 		return false, nil
 	}
 
-	rows, err := dependencyFile.ReadFileAsLines()
+	depFileData, err := dependencyFile.ReadFile()
 	if err != nil {
 		logrus.Debugf("Could not read dependency file: %s", dependencyFile)
 		return false, err
 	}
 
-	rows = f.Map(rows, removeEndingBackSlash)
-	rows = f.Map(rows, strings.TrimSpace)
-	rows = f.Map(rows, unescapeDep)
-	rows = f.Filter(rows, f.NotEquals(""))
+	checkDepFile := func(depFile string) (bool, error) {
+		rows := strings.Split(strings.Replace(depFile, "\r\n", "\n", -1), "\n")
+		rows = f.Map(rows, removeEndingBackSlash)
+		rows = f.Map(rows, strings.TrimSpace)
+		rows = f.Map(rows, unescapeDep)
+		rows = f.Filter(rows, f.NotEquals(""))
 
-	if len(rows) == 0 {
-		return true, nil
-	}
-
-	firstRow := rows[0]
-	if !strings.HasSuffix(firstRow, ":") {
-		logrus.Debugf("No colon in first line of depfile")
-		return false, nil
-	}
-	objFileInDepFile := firstRow[:len(firstRow)-1]
-	if objFileInDepFile != objectFile.String() {
-		logrus.Debugf("Depfile is about different object file: %v", objFileInDepFile)
-		return false, nil
-	}
-
-	// The first line of the depfile contains the path to the object file to generate.
-	// The second line of the depfile contains the path to the source file.
-	// All subsequent lines contain the header files necessary to compile the object file.
-
-	// If we don't do this check it might happen that trying to compile a source file
-	// that has the same name but a different path wouldn't recreate the object file.
-	if sourceFile.String() != strings.Trim(rows[1], " ") {
-		logrus.Debugf("Depfile is about different source file: %v", strings.Trim(rows[1], " "))
-		return false, nil
-	}
+		if len(rows) == 0 {
+			return true, nil
+		}
 
-	rows = rows[1:]
-	for _, row := range rows {
-		depStat, err := os.Stat(row)
-		if err != nil && !os.IsNotExist(err) {
-			// There is probably a parsing error of the dep file
-			// Ignore the error and trigger a full rebuild anyway
-			logrus.WithError(err).Debugf("Failed to read: %v", row)
+		firstRow := rows[0]
+		if !strings.HasSuffix(firstRow, ":") {
+			logrus.Debugf("No colon in first line of depfile")
 			return false, nil
 		}
-		if os.IsNotExist(err) {
-			logrus.Debugf("Not found: %v", row)
+		objFileInDepFile := firstRow[:len(firstRow)-1]
+		if objFileInDepFile != objectFile.String() {
+			logrus.Debugf("Depfile is about different object file: %v", objFileInDepFile)
 			return false, nil
 		}
-		if depStat.ModTime().After(objectFileStat.ModTime()) {
-			logrus.Debugf("%v newer than %v", row, objectFile)
+
+		// The first line of the depfile contains the path to the object file to generate.
+		// The second line of the depfile contains the path to the source file.
+		// All subsequent lines contain the header files necessary to compile the object file.
+
+		// If we don't do this check it might happen that trying to compile a source file
+		// that has the same name but a different path wouldn't recreate the object file.
+		if sourceFile.String() != strings.Trim(rows[1], " ") {
+			logrus.Debugf("Depfile is about different source file: %v", strings.Trim(rows[1], " "))
 			return false, nil
 		}
+
+		rows = rows[1:]
+		for _, row := range rows {
+			depStat, err := os.Stat(row)
+			if err != nil && !os.IsNotExist(err) {
+				// There is probably a parsing error of the dep file
+				// Ignore the error and trigger a full rebuild anyway
+				logrus.WithError(err).Debugf("Failed to read: %v", row)
+				return false, nil
+			}
+			if os.IsNotExist(err) {
+				logrus.Debugf("Not found: %v", row)
+				return false, nil
+			}
+			if depStat.ModTime().After(objectFileStat.ModTime()) {
+				logrus.Debugf("%v newer than %v", row, objectFile)
+				return false, nil
+			}
+		}
+
+		return true, nil
 	}
 
-	return true, nil
+	if runtime.GOOS == "windows" {
+		// This is required because on Windows we don't know which encoding is used
+		// by gcc to write the dep file (it could be UTF-8 or any of the Windows
+		// ANSI mappings).
+		if decoded, err := convertAnsiBytesToString(depFileData); err == nil {
+			if upToDate, err := checkDepFile(decoded); err == nil && upToDate {
+				return upToDate, nil
+			}
+		}
+		// Fallback to UTF-8...
+	}
+	return checkDepFile(string(depFileData))
 }
 
 func removeEndingBackSlash(s string) string {