arduino · iexavl · Jul 5, 2025 · Jul 8, 2025 · Jul 8, 2025
diff --git a/ls/ls.go b/ls/ls.go
@@ -83,6 +83,15 @@ type Config struct {
 	Jobs                            int
 }
 
+var extToFileType = map[string]string{
+	".h":   "cpp",
+	".hpp": "cpp",
+}
+
+type translationOpts struct {
+	loadRelToIde bool
+}
+
 var yellow = color.New(color.FgHiYellow)
 
 func (ls *INOLanguageServer) writeLock(logger jsonrpc.FunctionLogger, requireClangd bool) {
@@ -603,7 +612,8 @@ func (ls *INOLanguageServer) textDocumentDefinitionReqFromIDE(ctx context.Contex
 
 	var ideLocations []lsp.Location
 	if clangLocations != nil {
-		ideLocations, err = ls.clang2IdeLocationsArray(logger, clangLocations)
+		opts := translationOpts{loadRelToIde: true}
+		ideLocations, err = ls.clang2IdeLocationsArray2(logger, clangLocations, &opts)
 		if err != nil {
 			logger.Logf("Error: %v", err)
 			ls.Close()
@@ -989,15 +999,13 @@ func (ls *INOLanguageServer) exitNotifFromIDE(logger jsonrpc.FunctionLogger) {
 	ls.Close()
 }
 
-func (ls *INOLanguageServer) textDocumentDidOpenNotifFromIDE(logger jsonrpc.FunctionLogger, ideParam *lsp.DidOpenTextDocumentParams) {
-	ls.writeLock(logger, true)
-	defer ls.writeUnlock(logger)
+func (ls *INOLanguageServer) implTextDocumentDidOpenNotifFromIDE(logger jsonrpc.FunctionLogger, ideParam lsp.TextDocumentItem) *jsonrpc.ResponseError {
 
-	ideTextDocItem := ideParam.TextDocument
+	ideTextDocItem := ideParam
 	clangURI, _, err := ls.ide2ClangDocumentURI(logger, ideTextDocItem.URI)
 	if err != nil {
 		logger.Logf("Error: %s", err)
-		return
+		return &jsonrpc.ResponseError{Code: jsonrpc.ErrorCodesInternalError, Message: err.Error()}
 	}
 
 	if ls.ideURIIsPartOfTheSketch(ideTextDocItem.URI) {
@@ -1017,7 +1025,7 @@ func (ls *INOLanguageServer) textDocumentDidOpenNotifFromIDE(logger jsonrpc.Func
 		// Notify clangd that sketchCpp has been opened only once
 		if ls.sketchTrackedFilesCount != 1 {
 			logger.Logf("Clang already notified, do not notify it anymore")
-			return
+			return nil
 		}
 	}
 
@@ -1045,7 +1053,17 @@ func (ls *INOLanguageServer) textDocumentDidOpenNotifFromIDE(logger jsonrpc.Func
 		logger.Logf("Error sending notification to clangd server: %v", err)
 		logger.Logf("Please restart the language server.")
 		ls.Close()
+		return &jsonrpc.ResponseError{Code: jsonrpc.ErrorCodesInternalError, Message: err.Error()}
+
 	}
+	return nil
+
+}
+10000
+func (ls *INOLanguageServer) textDocumentDidOpenNotifFromIDE(logger jsonrpc.FunctionLogger, ideParam *lsp.DidOpenTextDocumentParams) {
+	ls.writeLock(logger, true)
+	defer ls.writeUnlock(logger)
+	ls.implTextDocumentDidOpenNotifFromIDE(logger, ideParam.TextDocument)
 }
 
 func (ls *INOLanguageServer) textDocumentDidChangeNotifFromIDE(logger jsonrpc.FunctionLogger, ideParams *lsp.DidChangeTextDocumentParams) {
@@ -1619,6 +1637,16 @@ type UnknownURIError struct {
 	URI lsp.DocumentURI
 }
 
+// UnknownFileExtensionError when a file extension isn't recognized
+// and a file with it has to be opened.
+type UnknownFileExtensionError struct {
+	extension string
+}
+
 func (e *UnknownURIError) Error() string {
 	return "Document is not available: " + e.URI.String()
 }
+
+func (e *UnknownFileExtensionError) Error() string {
+	return "Unknown file extension " + e.extension
+}
diff --git a/ls/ls_clang_to_ide.go b/ls/ls_clang_to_ide.go
@@ -27,12 +27,16 @@ func (ls *INOLanguageServer) clangURIRefersToIno(clangURI lsp.DocumentURI) bool
 	return clangURI.AsPath().EquivalentTo(ls.buildSketchCpp)
 }
 
+func (ls *INOLanguageServer) clang2IdeRangeAndDocumentURI(logger jsonrpc.FunctionLogger, clangURI lsp.DocumentURI, clangRange lsp.Range) (lsp.DocumentURI, lsp.Range, bool, error) {
+	return ls.clang2IdeRangeAndDocumentURI2(logger, clangURI, clangRange, nil)
+}
+
 // Convert Range and DocumentURI from Clang to IDE.
 // Returns:
 // - The IDE DocumentURI and Range
 // - a boolean that is true if the clang range is in the preprocessed area of the sketch
 // - an error
-func (ls *INOLanguageServer) clang2IdeRangeAndDocumentURI(logger jsonrpc.FunctionLogger, clangURI lsp.DocumentURI, clangRange lsp.Range) (lsp.DocumentURI, lsp.Range, bool, error) {
+func (ls *INOLanguageServer) clang2IdeRangeAndDocumentURI2(logger jsonrpc.FunctionLogger, clangURI lsp.DocumentURI, clangRange lsp.Range, opts *translationOpts) (lsp.DocumentURI, lsp.Range, bool, error) {
 	// Sketchbook/Sketch/Sketch.ino      <-> build-path/sketch/Sketch.ino.cpp
 	// Sketchbook/Sketch/AnotherTab.ino  <-> build-path/sketch/Sketch.ino.cpp  (different section from above)
 	if ls.clangURIRefersToIno(clangURI) {
@@ -80,7 +84,25 @@ func (ls *INOLanguageServer) clang2IdeRangeAndDocumentURI(logger jsonrpc.Functio
 		return lsp.NilURI, lsp.NilRange, false, err
 	}
 	idePath := ls.sketchRoot.JoinPath(rel).String()
-	ideURI, err := ls.idePathToIdeURI(logger, idePath)
+
+	var ideURI lsp.DocumentURI
+	if opts == nil || !opts.loadRelToIde {
+		ideURI, err = ls.idePathToIdeURI(logger, idePath)
+	} else {
+		doc, ok := ls.trackedIdeDocs[idePath]
+		if !ok {
+			var shouldOpen bool
+			doc, shouldOpen, err = makeTextDocumentItem(logger, idePath)
+			if err != nil {
+				logger.Logf("ERROR: could not open '%s': %s", idePath, err)
+			}
+			if shouldOpen {
+				ls.implTextDocumentDidOpenNotifFromIDE(logger, doc)
+			}
+
+		}
+		ideURI = doc.URI
+	}
 	if ideRange.End.Line > 0 {
 		ideRange.End.Line--
 	}
@@ -296,9 +318,12 @@ func (ls *INOLanguageServer) cland2IdeTextEdits(logger jsonrpc.FunctionLogger, c
 }
 
 func (ls *INOLanguageServer) clang2IdeLocationsArray(logger jsonrpc.FunctionLogger, clangLocations []lsp.Location) ([]lsp.Location, error) {
+	return ls.clang2IdeLocationsArray2(logger, clangLocations, nil)
+}
+func (ls *INOLanguageServer) clang2IdeLocationsArray2(logger jsonrpc.FunctionLogger, clangLocations []lsp.Location, opts *translationOpts) ([]lsp.Location, error) {
 	ideLocations := []lsp.Location{}
 	for _, clangLocation := range clangLocations {
-		ideLocation, inPreprocessed, err := ls.clang2IdeLocation(logger, clangLocation)
+		ideLocation, inPreprocessed, err := ls.clang2IdeLocation2(logger, clangLocation, opts)
 		if err != nil {
 			logger.Logf("ERROR converting location %s: %s", clangLocation, err)
 			return nil, err
@@ -313,7 +338,10 @@ func (ls *INOLanguageServer) clang2IdeLocationsArray(logger jsonrpc.FunctionLogg
 }
 
 func (ls *INOLanguageServer) clang2IdeLocation(logger jsonrpc.FunctionLogger, clangLocation lsp.Location) (lsp.Location, bool, error) {
-	ideURI, ideRange, inPreprocessed, err := ls.clang2IdeRangeAndDocumentURI(logger, clangLocation.URI, clangLocation.Range)
+	return ls.clang2IdeLocation2(logger, clangLocation, nil)
+}
+func (ls *INOLanguageServer) clang2IdeLocation2(logger jsonrpc.FunctionLogger, clangLocation lsp.Location, opts *translationOpts) (lsp.Location, bool, error) {
+	ideURI, ideRange, inPreprocessed, err := ls.clang2IdeRangeAndDocumentURI2(logger, clangLocation.URI, clangLocation.Range, opts)
 	return lsp.Location{
 		URI:   ideURI,
 		Range: ideRange,

diff --git a/ls/ls_ide_to_clang.go b/ls/ls_ide_to_clang.go
@@ -17,13 +17,43 @@
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
 
 	"github.com/arduino/arduino-language-server/sourcemapper"
 	"go.bug.st/lsp"
 	"go.bug.st/lsp/jsonrpc"
 )
 
+func getFileType(ext string) string {
+	if fileType, ok := extToFileType[ext]; ok {
+		return fileType
+	}
+	return "unknown"
+}
 func (ls *INOLanguageServer) idePathToIdeURI(logger jsonrpc.FunctionLogger, inoPath string) (lsp.DocumentURI, error) {
+	return ls.idePathToIdeURI2(logger, inoPath, nil)
+}
+
+func makeTextDocumentItem(logger jsonrpc.FunctionLogger, path string) (lsp.TextDocumentItem, bool, error) {
+	ext := filepath.Ext(path)
+	filetype := getFileType(path)
+	uri := lsp.NewDocumentURI(path)
+	if filetype == "unknown" {
+		return lsp.TextDocumentItem{URI: uri, LanguageID: filetype}, false, &UnknownFileExtensionError{ext}
+	}
+	languageID := filetype
+	version := 0
+
+	text, err := os.ReadFile(path)
+	if err != nil {
+		logger.Logf("Could not read file: %v", err)
+		return lsp.TextDocumentItem{}, false, err
+	}
+	return lsp.TextDocumentItem{URI: uri, LanguageID: languageID, Version: version, Text: string(text)}, true, nil
+
+}
+func (ls *INOLanguageServer) idePathToIdeURI2(logger jsonrpc.FunctionLogger, inoPath string) (lsp.DocumentURI, error) {
 	if inoPath == sourcemapper.NotIno.File {
 		return sourcemapper.NotInoURI, nil
 	}