Initial support to variables and to producer/consumer logic

cmd/mdt/main.go

@@ -3,6 +3,8 @@ package main
 import (
 	"bytes"
 	"os"
+	"path/filepath"
+	"strings"
 
 	"github.com/marte-community/marte-dev-tools/internal/builder"
 	"github.com/marte-community/marte-dev-tools/internal/formatter"
@@ -17,10 +19,6 @@ func main() {
 	if len(os.Args) < 2 {
 		logger.Println("Usage: mdt <command> [arguments]")
 		logger.Println("Commands: lsp, build, check, fmt, init")
-		logger.Println("  build [-o output_file] <input_files...>")
-		logger.Println("  check <input_files...>")
-		logger.Println("  fmt <input_files...>")
-		logger.Println("  init <project_name>")
 		os.Exit(1)
 	}
 
@@ -47,46 +45,47 @@ func runLSP() {
 }
 
 func runBuild(args []string) {
-	if len(args) < 1 {
+	files := []string{}
-		logger.Println("Usage: mdt build [-o output_file] <input_files...>")
+	overrides := make(map[string]string)
-		os.Exit(1)
+	outputFile := ""
-	}
-
-	var outputFilePath string
-	var inputFiles []string
 
 	for i := 0; i < len(args); i++ {
-		if args[i] == "-o" {
+		arg := args[i]
+		if strings.HasPrefix(arg, "-v") {
+			pair := arg[2:]
+			parts := strings.SplitN(pair, "=", 2)
+			if len(parts) == 2 {
+				overrides[parts[0]] = parts[1]
+			}
+		} else if arg == "-o" {
 			if i+1 < len(args) {
-				outputFilePath = args[i+1]
+				outputFile = args[i+1]
 				i++
-			} else {
-				logger.Println("Error: -o requires a file path")
-				os.Exit(1)
 			}
 		} else {
-			inputFiles = append(inputFiles, args[i])
+			files = append(files, arg)
 		}
 	}
 
-	if len(inputFiles) < 1 {
+	if len(files) < 1 {
-		logger.Println("Usage: mdt build [-o output_file] <input_files...>")
+		logger.Println("Usage: mdt build [-o output] [-vVAR=VAL] <input_files...>")
 		os.Exit(1)
 	}
 
-	output := os.Stdout
+	b := builder.NewBuilder(files, overrides)
-	if outputFilePath != "" {
+
-		f, err := os.Create(outputFilePath)
+	var out *os.File = os.Stdout
+	if outputFile != "" {
+		f, err := os.Create(outputFile)
 		if err != nil {
-			logger.Printf("Error creating output file %s: %v\n", outputFilePath, err)
+			logger.Printf("Error creating output file: %v\n", err)
 			os.Exit(1)
 		}
 		defer f.Close()
-		output = f
+		out = f
 	}
 
-	b := builder.NewBuilder(inputFiles)
+	err := b.Build(out)
-	err := b.Build(output)
 	if err != nil {
 		logger.Printf("Build failed: %v\n", err)
 		os.Exit(1)
@@ -175,23 +174,61 @@ func runInit(args []string) {
 	}
 
 	projectName := args[0]
-	if err := os.MkdirAll("src", 0755); err != nil {
+	if err := os.MkdirAll(filepath.Join(projectName, "src"), 0755); err != nil {
 		logger.Fatalf("Error creating project directories: %v", err)
 	}
 
 	files := map[string]string{
-		"Makefile":            "MDT=mdt\n\nall: check build\n\ncheck:\n\t$(MDT) check src/*.marte\n\nbuild:\n\t$(MDT) build -o app.marte src/*.marte\n\nfmt:\n\t$(MDT) fmt src/*.marte\n",
+		"Makefile": `MDT=mdt
-		".marte_schema.cue":   "package schema\n\n#Classes: {\n    // Add your project-specific classes here\n}\n",
+
-		"src/app.marte":       "#package " + projectName + "\n\n+App = {\n  Class = RealTimeApplication\n  +Data = {\n    Class = ReferenceContainer\n  }\n  +Functions = {\n    Class = ReferenceContainer\n  }\n  +States = {\n    Class = ReferenceContainer\n  }\n  +Scheduler = {\n    Class = GAMScheduler\n    TimingDataSource = TimingDataSource\n  }\n}\n",
+all: check build
-		"src/data.marte":      "#package " + projectName + ".App.Data\n\n// Define your DataSources here\nDefaultDataSource = DDB\n//# Default DB\n+DDB = {\n  Class=GAMDataSource\n}\n//# Timing Data Source to track threads timings\n+TimingDataSource = {\n  Class = TimingDataSource\n}",
+
-		"src/functions.marte": "#package " + projectName + ".App.Functions\n\n// Define your GAMs here\n",
+check:
+	$(MDT) check src/*.marte
+
+build:
+	$(MDT) build -o app.marte src/*.marte
+
+fmt:
+	$(MDT) fmt src/*.marte
+`,
+		".marte_schema.cue": `package schema
+
+#Classes: {
+    // Add your project-specific classes here
+}
+`,
+		"src/app.marte": `#package App
+
++Main = {
+    Class = RealTimeApplication
+    +States = {
+        Class = ReferenceContainer
+        +Run = {
+            Class = RealTimeState
+            +MainThread = {
+                Class = RealTimeThread
+                Functions = {}
+            }
+        }
+    }
+    +Data = {
+        Class = ReferenceContainer
+    }
+}
+`,
+		"src/components.marte": `#package App.Data
+
+// Define your DataSources here
+`,
 	}
 
 	for path, content := range files {
-		if err := os.WriteFile(path, []byte(content), 0644); err != nil {
+		fullPath := filepath.Join(projectName, path)
-			logger.Fatalf("Error creating file %s: %v", path, err)
+		if err := os.WriteFile(fullPath, []byte(content), 0644); err != nil {
+			logger.Fatalf("Error creating file %s: %v", fullPath, err)
 		}
-		logger.Printf("Created %s\n", path)
+		logger.Printf("Created %s\n", fullPath)
 	}
 
 	logger.Printf("Project '%s' initialized successfully.\n", projectName)

docs/CONFIGURATION_GUIDE.md

@@ -76,6 +76,8 @@ GAMs declare inputs and outputs. You can refer to signals directly or alias them
 ### Threading Rules
 **Validation Rule**: A DataSource that is **not** marked as multithreaded (default) cannot be used by GAMs running in different threads within the same State.
 
+**Ordering Rule**: For `INOUT` signals (data dependency within a thread), the Producer GAM must appear **before** the Consumer GAM in the thread's `Functions` list. This ensures correct data flow within the cycle. This rule is skipped if the DataSource is marked as `multithreaded: true`.
+
 To allow sharing, the DataSource class in the schema must have `#meta: multithreaded: true`.
 
 ## 3. Schemas and Validation
@@ -160,3 +162,27 @@ If validation is too strict, you can suppress warnings using pragmas (`//!`).
       Type = int32
   }
   ```
+
+## 6. Variables
+
+You can define variables using `#var`. The type expression supports CUE syntax.
+
+```marte
+#var MyVar: uint32 = 100
+#var Env: "PROD" | "DEV" = "DEV"
+```
+
+### Usage
+Reference a variable using `$`:
+
+```marte
+Field = $MyVar
+```
+
+### Build Override
+You can override variable values during build:
+
+```bash
+mdt build -vMyVar=200 -vEnv="PROD" src/*.marte
+```
+

internal/builder/builder.go

@@ -11,11 +11,13 @@ import (
 )
 
 type Builder struct {
-	Files []string
+	Files     []string
+	Overrides map[string]string
+	variables map[string]parser.Value
 }
 
-func NewBuilder(files []string) *Builder {
+func NewBuilder(files []string, overrides map[string]string) *Builder {
-	return &Builder{Files: files}
+	return &Builder{Files: files, Overrides: overrides, variables: make(map[string]parser.Value)}
 }
 
 func (b *Builder) Build(f *os.File) error {
@@ -56,6 +58,22 @@ func (b *Builder) Build(f *os.File) error {
 		tree.AddFile(file, config)
 	}
 
+	b.collectVariables(tree)
+
+	if expectedProject == "" {
+		for _, iso := range tree.IsolatedFiles {
+			tree.Root.Fragments = append(tree.Root.Fragments, iso.Fragments...)
+			for name, child := range iso.Children {
+				if existing, ok := tree.Root.Children[name]; ok {
+					b.mergeNodes(existing, child)
+				} else {
+					tree.Root.Children[name] = child
+					child.Parent = tree.Root
+				}
+			}
+		}
+	}
+
 	// Determine root node to print
 	rootNode := tree.Root
 	if expectedProject != "" {
@@ -102,6 +120,8 @@ func (b *Builder) writeNodeBody(f *os.File, node *index.ProjectNode, indent int)
 			switch d := def.(type) {
 			case *parser.Field:
 				b.writeDefinition(f, d, indent)
+			case *parser.VariableDefinition:
+				continue
 			case *parser.ObjectNode:
 				norm := index.NormalizeName(d.Name)
 				if child, ok := node.Children[norm]; ok {
@@ -150,6 +170,12 @@ func (b *Builder) formatValue(val parser.Value) string {
 		return v.Raw
 	case *parser.BoolValue:
 		return fmt.Sprintf("%v", v.Value)
+	case *parser.VariableReferenceValue:
+		name := strings.TrimPrefix(v.Name, "$")
+		if val, ok := b.variables[name]; ok {
+			return b.formatValue(val)
+		}
+		return v.Name
 	case *parser.ReferenceValue:
 		return v.Value
 	case *parser.ArrayValue:
@@ -163,6 +189,18 @@ func (b *Builder) formatValue(val parser.Value) string {
 	}
 }
 
+func (b *Builder) mergeNodes(dest, src *index.ProjectNode) {
+	dest.Fragments = append(dest.Fragments, src.Fragments...)
+	for name, child := range src.Children {
+		if existing, ok := dest.Children[name]; ok {
+			b.mergeNodes(existing, child)
+		} else {
+			dest.Children[name] = child
+			child.Parent = dest
+		}
+	}
+}
+
 func hasClass(frag *index.Fragment) bool {
 	for _, def := range frag.Definitions {
 		if f, ok := def.(*parser.Field); ok && f.Name == "Class" {
@@ -171,3 +209,28 @@ func hasClass(frag *index.Fragment) bool {
 	}
 	return false
 }
+
+func (b *Builder) collectVariables(tree *index.ProjectTree) {
+	processNode := func(n *index.ProjectNode) {
+		for _, frag := range n.Fragments {
+			for _, def := range frag.Definitions {
+				if vdef, ok := def.(*parser.VariableDefinition); ok {
+					if valStr, ok := b.Overrides[vdef.Name]; ok {
+						p := parser.NewParser("Temp = " + valStr)
+						cfg, _ := p.Parse()
+						if len(cfg.Definitions) > 0 {
+							if f, ok := cfg.Definitions[0].(*parser.Field); ok {
+								b.variables[vdef.Name] = f.Value
+								continue
+							}
+						}
+					}
+					if vdef.DefaultValue != nil {
+						b.variables[vdef.Name] = vdef.DefaultValue
+					}
+				}
+			}
+		}
+	}
+	tree.Walk(processNode)
+}

internal/formatter/formatter.go

@@ -104,6 +104,14 @@ func (f *Formatter) formatDefinition(def parser.Definition, indent int) int {
 
 		fmt.Fprintf(f.writer, "%s}", indentStr)
 		return d.Subnode.EndPosition.Line
+	case *parser.VariableDefinition:
+		fmt.Fprintf(f.writer, "%s#var %s: %s", indentStr, d.Name, d.TypeExpr)
+		if d.DefaultValue != nil {
+			fmt.Fprint(f.writer, " = ")
+			endLine := f.formatValue(d.DefaultValue, indent)
+			return endLine
+		}
+		return d.Position.Line
 	}
 	return 0
 }
@@ -142,6 +150,9 @@ func (f *Formatter) formatValue(val parser.Value, indent int) int {
 	case *parser.ReferenceValue:
 		fmt.Fprint(f.writer, v.Value)
 		return v.Position.Line
+	case *parser.VariableReferenceValue:
+		fmt.Fprint(f.writer, v.Name)
+		return v.Position.Line
 	case *parser.ArrayValue:
 		fmt.Fprint(f.writer, "{ ")
 		for i, e := range v.Elements {

internal/index/index.go

@@ -8,12 +8,18 @@ import (
 	"github.com/marte-community/marte-dev-tools/internal/parser"
 )
 
+type VariableInfo struct {
+	Def  *parser.VariableDefinition
+	File string
+}
+
 type ProjectTree struct {
 	Root          *ProjectNode
 	References    []Reference
 	IsolatedFiles map[string]*ProjectNode
 	GlobalPragmas map[string][]string
 	NodeMap       map[string][]*ProjectNode
+	Variables     map[string]VariableInfo
 }
 
 func (pt *ProjectTree) ScanDirectory(rootPath string) error {
@@ -37,10 +43,11 @@ func (pt *ProjectTree) ScanDirectory(rootPath string) error {
 }
 
 type Reference struct {
-	Name     string
+	Name           string
-	Position parser.Position
+	Position       parser.Position
-	File     string
+	File           string
-	Target   *ProjectNode // Resolved target
+	Target         *ProjectNode
+	TargetVariable *parser.VariableDefinition
 }
 
 type ProjectNode struct {
@@ -72,6 +79,7 @@ func NewProjectTree() *ProjectTree {
 		},
 		IsolatedFiles: make(map[string]*ProjectNode),
 		GlobalPragmas: make(map[string][]string),
+		Variables:     make(map[string]VariableInfo),
 	}
 }
 
@@ -219,6 +227,9 @@ func (pt *ProjectTree) populateNode(node *ProjectNode, file string, config *pars
 		case *parser.Field:
 			fileFragment.Definitions = append(fileFragment.Definitions, d)
 			pt.indexValue(file, d.Value)
+		case *parser.VariableDefinition:
+			fileFragment.Definitions = append(fileFragment.Definitions, d)
+			pt.Variables[d.Name] = VariableInfo{Def: d, File: file}
 		case *parser.ObjectNode:
 			fileFragment.Definitions = append(fileFragment.Definitions, d)
 			norm := NormalizeName(d.Name)
@@ -274,6 +285,9 @@ func (pt *ProjectTree) addObjectFragment(node *ProjectNode, file string, obj *pa
 			frag.Definitions = append(frag.Definitions, d)
 			pt.indexValue(file, d.Value)
 			pt.extractFieldMetadata(node, d)
+		case *parser.VariableDefinition:
+			frag.Definitions = append(frag.Definitions, d)
+			pt.Variables[d.Name] = VariableInfo{Def: d, File: file}
 		case *parser.ObjectNode:
 			frag.Definitions = append(frag.Definitions, d)
 			norm := NormalizeName(d.Name)
@@ -379,6 +393,12 @@ func (pt *ProjectTree) indexValue(file string, val parser.Value) {
 			Position: v.Position,
 			File:     file,
 		})
+	case *parser.VariableReferenceValue:
+		pt.References = append(pt.References, Reference{
+			Name:     strings.TrimPrefix(v.Name, "$"),
+			Position: v.Position,
+			File:     file,
+		})
 	case *parser.ArrayValue:
 		for _, elem := range v.Elements {
 			pt.indexValue(file, elem)
@@ -401,6 +421,12 @@ func (pt *ProjectTree) ResolveReferences() {
 	pt.RebuildIndex()
 	for i := range pt.References {
 		ref := &pt.References[i]
+
+		if v, ok := pt.Variables[ref.Name]; ok {
+			ref.TargetVariable = v.Def
+			continue
+		}
+
 		if isoNode, ok := pt.IsolatedFiles[ref.File]; ok {
 			ref.Target = pt.FindNode(isoNode, ref.Name, nil)
 		} else {
@@ -479,6 +505,7 @@ type QueryResult struct {
 	Node      *ProjectNode
 	Field     *parser.Field
 	Reference *Reference
+	Variable  *parser.VariableDefinition
 }
 
 func (pt *ProjectTree) Query(file string, line, col int) *QueryResult {
@@ -528,6 +555,10 @@ func (pt *ProjectTree) queryNode(node *ProjectNode, file string, line, col int)
 					if line == f.Position.Line && col >= f.Position.Column && col < f.Position.Column+len(f.Name) {
 						return &QueryResult{Field: f}
 					}
+				} else if v, ok := def.(*parser.VariableDefinition); ok {
+					if line == v.Position.Line {
+						return &QueryResult{Variable: v}
+					}
 				}
 			}
 		}

internal/lsp/server.go

@@ -591,6 +591,8 @@ func HandleHover(params HoverParams) *Hover {
 		}
 	} else if res.Field != nil {
 		content = fmt.Sprintf("**Field**: `%s`", res.Field.Name)
+	} else if res.Variable != nil {
+		content = fmt.Sprintf("**Variable**: `%s`\nType: `%s`", res.Variable.Name, res.Variable.TypeExpr)
 	} else if res.Reference != nil {
 		targetName := "Unresolved"
 		fullInfo := ""
@@ -600,6 +602,10 @@ func HandleHover(params HoverParams) *Hover {
 			targetName = res.Reference.Target.RealName
 			targetDoc = res.Reference.Target.Doc
 			fullInfo = formatNodeInfo(res.Reference.Target)
+		} else if res.Reference.TargetVariable != nil {
+			v := res.Reference.TargetVariable
+			targetName = v.Name
+			fullInfo = fmt.Sprintf("**Variable**: `%s`\nType: `%s`", v.Name, v.TypeExpr)
 		}
 
 		content = fmt.Sprintf("**Reference**: `%s` -> `%s`", res.Reference.Name, targetName)

internal/parser/ast.go

@@ -125,3 +125,21 @@ type Pragma struct {
 }
 
 func (p *Pragma) Pos() Position { return p.Position }
+
+type VariableDefinition struct {
+	Position     Position
+	Name         string
+	TypeExpr     string
+	DefaultValue Value
+}
+
+func (v *VariableDefinition) Pos() Position { return v.Position }
+func (v *VariableDefinition) isDefinition() {}
+
+type VariableReferenceValue struct {
+	Position Position
+	Name     string
+}
+
+func (v *VariableReferenceValue) Pos() Position { return v.Position }
+func (v *VariableReferenceValue) isValue()      {}

internal/parser/lexer.go

@@ -23,6 +23,11 @@ const (
 	TokenComment
 	TokenDocstring
 	TokenComma
+	TokenColon
+	TokenPipe
+	TokenLBracket
+	TokenRBracket
+	TokenSymbol
 )
 
 type Token struct {
@@ -124,6 +129,16 @@ func (l *Lexer) NextToken() Token {
 			return l.emit(TokenRBrace)
 		case ',':
 			return l.emit(TokenComma)
+		case ':':
+			return l.emit(TokenColon)
+		case '|':
+			return l.emit(TokenPipe)
+		case '[':
+			return l.emit(TokenLBracket)
+		case ']':
+			return l.emit(TokenRBracket)
+		case '&', '?', '!', '<', '>', '*', '(', ')':
+			return l.emit(TokenSymbol)
 		case '"':
 			return l.lexString()
 		case '/':
@@ -151,7 +166,7 @@ func (l *Lexer) NextToken() Token {
 func (l *Lexer) lexIdentifier() Token {
 	for {
 		r := l.next()
-		if unicode.IsLetter(r) || unicode.IsDigit(r) || r == '_' || r == '-' || r == '.' || r == ':' {
+		if unicode.IsLetter(r) || unicode.IsDigit(r) || r == '_' || r == '-' || r == '.' {
 			continue
 		}
 		l.backup()
@@ -247,7 +262,7 @@ func (l *Lexer) lexHashIdentifier() Token {
 	// We are at '#', l.start is just before it
 	for {
 		r := l.next()
-		if unicode.IsLetter(r) || unicode.IsDigit(r) || r == '_' || r == '-' || r == '.' || r == ':' || r == '#' {
+		if unicode.IsLetter(r) || unicode.IsDigit(r) || r == '_' || r == '-' || r == '.' || r == '#' {
 			continue
 		}
 		l.backup()

internal/parser/parser.go

@@ -101,6 +101,9 @@ func (p *Parser) parseDefinition() (Definition, bool) {
 	switch tok.Type {
 	case TokenIdentifier:
 		name := tok.Value
+		if name == "#var" {
+			return p.parseVariableDefinition(tok)
+		}
 		if p.peek().Type != TokenEqual {
 			p.addError(tok.Position, "expected =")
 			return nil, false
@@ -244,6 +247,8 @@ func (p *Parser) parseValue() (Value, bool) {
 			true
 	case TokenIdentifier:
 		return &ReferenceValue{Position: tok.Position, Value: tok.Value}, true
+	case TokenObjectIdentifier:
+		return &VariableReferenceValue{Position: tok.Position, Name: tok.Value}, true
 	case TokenLBrace:
 		arr := &ArrayValue{Position: tok.Position}
 		for {
@@ -269,3 +274,53 @@ func (p *Parser) parseValue() (Value, bool) {
 		return nil, false
 	}
 }
+
+func (p *Parser) parseVariableDefinition(startTok Token) (Definition, bool) {
+	nameTok := p.next()
+	if nameTok.Type != TokenIdentifier {
+		p.addError(nameTok.Position, "expected variable name")
+		return nil, false
+	}
+
+	if p.next().Type != TokenColon {
+		p.addError(nameTok.Position, "expected :")
+		return nil, false
+	}
+
+	var typeTokens []Token
+	startLine := nameTok.Position.Line
+
+	for {
+		t := p.peek()
+		if t.Position.Line > startLine || t.Type == TokenEOF {
+			break
+		}
+		if t.Type == TokenEqual {
+			break
+		}
+		typeTokens = append(typeTokens, p.next())
+	}
+
+	typeExpr := ""
+	for _, t := range typeTokens {
+		typeExpr += t.Value + " "
+	}
+
+	var defVal Value
+	if p.peek().Type == TokenEqual {
+		p.next()
+		val, ok := p.parseValue()
+		if ok {
+			defVal = val
+		} else {
+			return nil, false
+		}
+	}
+
+	return &VariableDefinition{
+		Position:     startTok.Position,
+		Name:         nameTok.Value,
+		TypeExpr:     strings.TrimSpace(typeExpr),
+		DefaultValue: defVal,
+	}, true
+}

internal/schema/marte.cue

@@ -413,7 +413,7 @@ package schema
 	OPCUA: {...}
 	SysLogger: {...}
 	GAMDataSource: {
-		#meta: multithreaded: bool | *false
+		#meta: multithreaded: false
 		#meta: direction:     "INOUT"
 		#meta: type:          "datasource"
 		...
@@ -421,7 +421,7 @@ package schema
 }
 
 #Meta: {
-	direction?: "IN" | "OUT" | "INOUT"
+	direction?:     "IN" | "OUT" | "INOUT"
 	multithreaded?: bool
 	...
 }
@@ -430,7 +430,7 @@ package schema
 // It must have a Class field.
 // Based on Class, it validates against #Classes.
 #Object: {
-	Class: string
+	Class:    string
 	"#meta"?: #Meta
 	// Allow any other field by default (extensibility),
 	// unless #Classes definition is closed.

internal/validator/validator.go

@@ -55,6 +55,8 @@ func (v *Validator) ValidateProject() {
 	}
 	v.CheckUnused()
 	v.CheckDataSourceThreading()
+	v.CheckINOUTOrdering()
+	v.CheckVariables()
 }
 
 func (v *Validator) validateNode(node *index.ProjectNode) {
@@ -884,3 +886,218 @@ func (v *Validator) isMultithreaded(ds *index.ProjectNode) bool {
 	}
 	return false
 }
+
+func (v *Validator) CheckINOUTOrdering() {
+	if v.Tree.Root == nil {
+		return
+	}
+
+	var appNode *index.ProjectNode
+	findApp := func(n *index.ProjectNode) {
+		if cls, ok := n.Metadata["Class"]; ok && cls == "RealTimeApplication" {
+			appNode = n
+		}
+	}
+	v.Tree.Walk(findApp)
+
+	if appNode == nil {
+		return
+	}
+
+	var statesNode *index.ProjectNode
+	if s, ok := appNode.Children["States"]; ok {
+		statesNode = s
+	} else {
+		for _, child := range appNode.Children {
+			if cls, ok := child.Metadata["Class"]; ok && cls == "StateMachine" {
+				statesNode = child
+				break
+			}
+		}
+	}
+
+	if statesNode == nil {
+		return
+	}
+
+	for _, state := range statesNode.Children {
+		var threads []*index.ProjectNode
+		for _, child := range state.Children {
+			if child.RealName == "Threads" {
+				for _, t := range child.Children {
+					if cls, ok := t.Metadata["Class"]; ok && cls == "RealTimeThread" {
+						threads = append(threads, t)
+					}
+				}
+			} else {
+				if cls, ok := child.Metadata["Class"]; ok && cls == "RealTimeThread" {
+					threads = append(threads, child)
+				}
+			}
+		}
+
+		for _, thread := range threads {
+			producedSignals := make(map[*index.ProjectNode]map[string][]*index.ProjectNode)
+			consumedSignals := make(map[*index.ProjectNode]map[string]bool)
+
+			gams := v.getThreadGAMs(thread)
+			for _, gam := range gams {
+				v.processGAMSignalsForOrdering(gam, "InputSignals", producedSignals, consumedSignals, true, thread, state)
+				v.processGAMSignalsForOrdering(gam, "OutputSignals", producedSignals, consumedSignals, false, thread, state)
+			}
+
+			// Check for produced but not consumed
+			for ds, signals := range producedSignals {
+				for sigName, producers := range signals {
+					consumed := false
+					if cSet, ok := consumedSignals[ds]; ok {
+						if cSet[sigName] {
+							consumed = true
+						}
+					}
+					if !consumed {
+						for _, prod := range producers {
+							v.Diagnostics = append(v.Diagnostics, Diagnostic{
+								Level:    LevelWarning,
+								Message:  fmt.Sprintf("INOUT Signal '%s' (DS '%s') is produced in thread '%s' but never consumed in the same thread.", sigName, ds.RealName, thread.RealName),
+								Position: v.getNodePosition(prod),
+								File:     v.getNodeFile(prod),
+							})
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+func (v *Validator) processGAMSignalsForOrdering(gam *index.ProjectNode, containerName string, produced map[*index.ProjectNode]map[string][]*index.ProjectNode, consumed map[*index.ProjectNode]map[string]bool, isInput bool, thread, state *index.ProjectNode) {
+	container := gam.Children[containerName]
+	if container == nil {
+		return
+	}
+
+	for _, sig := range container.Children {
+		fields := v.getFields(sig)
+		var dsNode *index.ProjectNode
+		var sigName string
+
+		if sig.Target != nil {
+			if sig.Target.Parent != nil && sig.Target.Parent.Parent != nil {
+				dsNode = sig.Target.Parent.Parent
+				sigName = sig.Target.RealName
+			}
+		}
+
+		if dsNode == nil {
+			if dsFields, ok := fields["DataSource"]; ok && len(dsFields) > 0 {
+				dsName := v.getFieldValue(dsFields[0])
+				dsNode = v.resolveReference(dsName, v.getNodeFile(sig), isDataSource)
+			}
+			if aliasFields, ok := fields["Alias"]; ok && len(aliasFields) > 0 {
+				sigName = v.getFieldValue(aliasFields[0])
+			} else {
+				sigName = sig.RealName
+			}
+		}
+
+		if dsNode == nil || sigName == "" {
+			continue
+		}
+
+		sigName = index.NormalizeName(sigName)
+
+		if v.isMultithreaded(dsNode) {
+			continue
+		}
+
+		dir := v.getDataSourceDirection(dsNode)
+		if dir != "INOUT" {
+			continue
+		}
+
+		if isInput {
+			isProduced := false
+			if set, ok := produced[dsNode]; ok {
+				if len(set[sigName]) > 0 {
+					isProduced = true
+				}
+			}
+
+			if !isProduced {
+				v.Diagnostics = append(v.Diagnostics, Diagnostic{
+					Level:    LevelError,
+					Message:  fmt.Sprintf("INOUT Signal '%s' (DS '%s') is consumed by GAM '%s' in thread '%s' (State '%s') before being produced by any previous GAM.", sigName, dsNode.RealName, gam.RealName, thread.RealName, state.RealName),
+					Position: v.getNodePosition(sig),
+					File:     v.getNodeFile(sig),
+				})
+			}
+
+			if consumed[dsNode] == nil {
+				consumed[dsNode] = make(map[string]bool)
+			}
+			consumed[dsNode][sigName] = true
+		} else {
+			if produced[dsNode] == nil {
+				produced[dsNode] = make(map[string][]*index.ProjectNode)
+			}
+			produced[dsNode][sigName] = append(produced[dsNode][sigName], sig)
+		}
+	}
+}
+
+func (v *Validator) getDataSourceDirection(ds *index.ProjectNode) string {
+	cls := v.getNodeClass(ds)
+	if cls == "" {
+		return ""
+	}
+	if v.Schema == nil {
+		return ""
+	}
+	path := cue.ParsePath(fmt.Sprintf("#Classes.%s.#meta.direction", cls))
+	val := v.Schema.Value.LookupPath(path)
+	if val.Err() == nil {
+		s, _ := val.String()
+		return s
+	}
+	return ""
+}
+
+func (v *Validator) CheckVariables() {
+	if v.Schema == nil {
+		return
+	}
+	ctx := v.Schema.Context
+
+	for _, info := range v.Tree.Variables {
+		def := info.Def
+
+		// Compile Type
+		typeVal := ctx.CompileString(def.TypeExpr)
+		if typeVal.Err() != nil {
+			v.Diagnostics = append(v.Diagnostics, Diagnostic{
+				Level:    LevelError,
+				Message:  fmt.Sprintf("Invalid type expression for variable '%s': %v", def.Name, typeVal.Err()),
+				Position: def.Position,
+				File:     info.File,
+			})
+			continue
+		}
+
+		if def.DefaultValue != nil {
+			valInterface := v.valueToInterface(def.DefaultValue)
+			valVal := ctx.Encode(valInterface)
+
+			// Unify
+			res := typeVal.Unify(valVal)
+			if err := res.Validate(cue.Concrete(true)); err != nil {
+				v.Diagnostics = append(v.Diagnostics, Diagnostic{
+					Level:    LevelError,
+					Message:  fmt.Sprintf("Variable '%s' value mismatch: %v", def.Name, err),
+					Position: def.Position,
+					File:     info.File,
+				})
+			}
+		}
+	}
+}

test/builder_multifile_test.go

@@ -32,7 +32,7 @@ FieldB = 20
 	os.WriteFile("build_multi_test/f2.marte", []byte(f2Content), 0644)
 
 	// Execute Build
-	b := builder.NewBuilder([]string{"build_multi_test/f1.marte", "build_multi_test/f2.marte"})
+	b := builder.NewBuilder([]string{"build_multi_test/f1.marte", "build_multi_test/f2.marte"}, nil)
 
 	// Prepare output file
 	// Should be +MyObj.marte (normalized MyObj.marte) - Actually checking content

test/formatter_variables_test.go

@@ -0,0 +1,45 @@
+package integration
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/formatter"
+	"github.com/marte-community/marte-dev-tools/internal/parser"
+)
+
+func TestFormatterVariables(t *testing.T) {
+	content := `
+#var MyInt: int = 10
+#var MyStr: string | "A" = "default"
+
++Obj = {
+    Field1 = $MyInt
+    Field2 = $MyStr
+}
+`
+	p := parser.NewParser(content)
+	cfg, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	var buf bytes.Buffer
+	formatter.Format(cfg, &buf)
+
+	output := buf.String()
+
+	// Parser reconstructs type expression with spaces
+	if !strings.Contains(output, "#var MyInt: int = 10") {
+		t.Errorf("Variable MyInt formatted incorrectly. Got:\n%s", output)
+	}
+	// Note: parser adds space after each token in TypeExpr
+	// string | "A" -> "string | \"A\"" 
+	if !strings.Contains(output, "#var MyStr: string | \"A\" = \"default\"") {
+		t.Errorf("Variable MyStr formatted incorrectly. Got:\n%s", output)
+	}
+	if !strings.Contains(output, "Field1 = $MyInt") {
+		t.Errorf("Variable reference $MyInt formatted incorrectly. Got:\n%s", output)
+	}
+}

test/integration_test.go

@@ -168,7 +168,7 @@ func TestBuildCommand(t *testing.T) {
 
 	// Test Merge
 	files := []string{"integration/build_merge_1.marte", "integration/build_merge_2.marte"}
-	b := builder.NewBuilder(files)
+	b := builder.NewBuilder(files, nil)
 
 	outputFile, err := os.Create("build_test/TEST.marte")
 	if err != nil {
@@ -195,7 +195,7 @@ func TestBuildCommand(t *testing.T) {
 
 	// Test Order (Class First)
 	filesOrder := []string{"integration/build_order_1.marte", "integration/build_order_2.marte"}
-	bOrder := builder.NewBuilder(filesOrder)
+	bOrder := builder.NewBuilder(filesOrder, nil)
 
 	outputFileOrder, err := os.Create("build_test/ORDER.marte")
 	if err != nil {

test/lsp_inout_test.go

@@ -0,0 +1,73 @@
+package integration
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/index"
+	"github.com/marte-community/marte-dev-tools/internal/lsp"
+	"github.com/marte-community/marte-dev-tools/internal/schema"
+)
+
+func TestLSPINOUTOrdering(t *testing.T) {
+	lsp.Tree = index.NewProjectTree()
+	lsp.Documents = make(map[string]string)
+	// Mock schema if necessary, but we rely on internal schema
+	lsp.GlobalSchema = schema.LoadFullSchema(".")
+
+	var buf bytes.Buffer
+	lsp.Output = &buf
+
+	content := `
++App = {
+  Class = RealTimeApplication
+  +Data = {
+    Class = ReferenceContainer
+    +DDB = {
+      Class = GAMDataSource
+    }
+  }
+  +Functions = {
+    Class = ReferenceContainer
+    +A = {
+      Class = IOGAM
+      InputSignals = {
+        A = {
+          DataSource = DDB
+          Type = uint32
+        }
+      }
+      OutputSignals = {
+        B = {
+          DataSource = DDB
+          Type = uint32
+        }
+      }
+    }
+  }
+  +States = {
+    Class = ReferenceContainer
+    +State = {
+      Class =RealTimeState
+      Threads = {
+        +Th1 = {
+          Class = RealTimeThread
+          Functions = {A}
+        }
+      }
+    }
+  }
+}
+`
+	uri := "file://app.marte"
+	lsp.HandleDidOpen(lsp.DidOpenTextDocumentParams{
+		TextDocument: lsp.TextDocumentItem{URI: uri, Text: content},
+	})
+
+	output := buf.String()
+	if !strings.Contains(output, "INOUT Signal 'A'") {
+		t.Error("LSP did not report INOUT ordering error")
+		t.Log(output)
+	}
+}

test/lsp_inout_warning_test.go

@@ -0,0 +1,66 @@
+package integration
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/index"
+	"github.com/marte-community/marte-dev-tools/internal/lsp"
+	"github.com/marte-community/marte-dev-tools/internal/schema"
+)
+
+func TestLSPINOUTWarning(t *testing.T) {
+	lsp.Tree = index.NewProjectTree()
+	lsp.Documents = make(map[string]string)
+	lsp.GlobalSchema = schema.LoadFullSchema(".")
+
+	var buf bytes.Buffer
+	lsp.Output = &buf
+
+	content := `
++App = {
+  Class = RealTimeApplication
+  +Data = {
+    Class = ReferenceContainer
+    +DDB = {
+      Class = GAMDataSource
+    }
+  }
+  +Functions = {
+    Class = ReferenceContainer
+    +Producer = {
+      Class = IOGAM
+      OutputSignals = {
+        ProducedSig = {
+          DataSource = DDB
+          Type = uint32
+        }
+      }
+    }
+  }
+  +States = {
+    Class = ReferenceContainer
+    +State = {
+      Class =RealTimeState
+      Threads = {
+        +Th1 = {
+          Class = RealTimeThread
+          Functions = {Producer}
+        }
+      }
+    }
+  }
+}
+`
+	uri := "file://warning.marte"
+	lsp.HandleDidOpen(lsp.DidOpenTextDocumentParams{
+		TextDocument: lsp.TextDocumentItem{URI: uri, Text: content},
+	})
+
+	output := buf.String()
+	if !strings.Contains(output, "produced in thread '+Th1' but never consumed") {
+		t.Error("LSP did not report INOUT usage warning")
+		t.Log(output)
+	}
+}

test/validator_inout_ordering_test.go

@@ -0,0 +1,93 @@
+package integration
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/index"
+	"github.com/marte-community/marte-dev-tools/internal/parser"
+	"github.com/marte-community/marte-dev-tools/internal/validator"
+)
+
+func TestINOUTOrdering(t *testing.T) {
+	content := `
++Data = {
+    Class = ReferenceContainer
+    +MyDS = {
+        Class = GAMDataSource
+        #meta = { multithreaded = false } // Explicitly false
+        Signals = { Sig1 = { Type = uint32 } }
+    }
+}
++GAM_Consumer = {
+    Class = IOGAM
+    InputSignals = {
+        Sig1 = { DataSource = MyDS Type = uint32 }
+    }
+}
++GAM_Producer = {
+    Class = IOGAM
+    OutputSignals = {
+        Sig1 = { DataSource = MyDS Type = uint32 }
+    }
+}
++App = {
+    Class = RealTimeApplication
+    +States = {
+        Class = ReferenceContainer
+        +State1 = {
+            Class = RealTimeState
+            +Thread1 = {
+                Class = RealTimeThread
+                Functions = { GAM_Consumer, GAM_Producer } // Fail
+            }
+        }
+        +State2 = {
+            Class = RealTimeState
+            +Thread2 = {
+                Class = RealTimeThread
+                Functions = { GAM_Producer, GAM_Consumer } // Pass
+            }
+        }
+    }
+}
+`
+	pt := index.NewProjectTree()
+	p := parser.NewParser(content)
+	cfg, err := p.Parse()
+	if err != nil {
+		t.Fatal(err)
+	}
+	pt.AddFile("main.marte", cfg)
+
+	// Use validator with default schema (embedded)
+	// We pass "." but it shouldn't matter if no .marte_schema.cue exists
+	v := validator.NewValidator(pt, ".")
+	v.ValidateProject()
+
+	foundError := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "consumed by GAM '+GAM_Consumer'") &&
+			strings.Contains(d.Message, "before being produced") {
+			foundError = true
+		}
+	}
+
+	if !foundError {
+		t.Error("Expected INOUT ordering error for State1")
+		for _, d := range v.Diagnostics {
+			t.Logf("Diag: %s", d.Message)
+		}
+	}
+
+	foundErrorState2 := false
+	for _, d := range v.Diagnostics {
+		if strings.Contains(d.Message, "State '+State2'") && strings.Contains(d.Message, "before being produced") {
+			foundErrorState2 = true
+		}
+	}
+
+	if foundErrorState2 {
+		t.Error("Unexpected INOUT ordering error for State2 (Correct order)")
+	}
+}

test/variables_test.go

@@ -0,0 +1,72 @@
+package integration
+
+import (
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/builder"
+	"github.com/marte-community/marte-dev-tools/internal/parser"
+)
+
+func TestVariables(t *testing.T) {
+	content := `
+#var MyInt: int = 10
+#var MyStr: string = "default"
+
++Obj = {
+    Class = Test
+    Field1 = $MyInt
+    Field2 = $MyStr
+}
+`
+	// Test Parsing
+	p := parser.NewParser(content)
+	cfg, err := p.Parse()
+	if err != nil {
+		t.Fatalf("Parse failed: %v", err)
+	}
+
+	// Check definitions: #var, #var, +Obj
+	if len(cfg.Definitions) != 3 {
+		t.Errorf("Expected 3 definitions, got %d", len(cfg.Definitions))
+	}
+
+	// Test Builder resolution
+	f, _ := os.CreateTemp("", "vars.marte")
+	f.WriteString(content)
+	f.Close()
+	defer os.Remove(f.Name())
+
+	// Build with override
+	overrides := map[string]string{
+		"MyInt": "999",
+	}
+
+	b := builder.NewBuilder([]string{f.Name()}, overrides)
+
+	outF, _ := os.CreateTemp("", "out.marte")
+	outName := outF.Name()
+	defer os.Remove(outName)
+
+	err = b.Build(outF)
+	outF.Close()
+
+	if err != nil {
+		t.Fatalf("Build failed: %v", err)
+	}
+
+	outContent, _ := os.ReadFile(outName)
+	outStr := string(outContent)
+
+	if !strings.Contains(outStr, "Field1 = 999") {
+		t.Errorf("Variable override failed for MyInt. Got:\n%s", outStr)
+	}
+	if !strings.Contains(outStr, "Field2 = \"default\"") {
+		t.Errorf("Default value failed for MyStr. Got:\n%s", outStr)
+	}
+	// Check #var is removed
+	if strings.Contains(outStr, "#var") {
+		t.Error("#var definition present in output")
+	}
+}