added block and no return value generation

asm/amd64/amd64.go

@@ -6,7 +6,16 @@ import (
 )
 
 type Program struct {
-	Functions []Function
+	Functions    []Function
+	MainFunction *Function
+}
+
+func (p *Program) executableAsmHeader() string {
+
+	if p.MainFunction.HasReturnValue {
+		return executableAsmHeader
+	}
+	return executableAsmHeaderNoReturnValue
 }
 
 // This calls the main function and uses it's return value to exit
@@ -19,9 +28,18 @@ const executableAsmHeader = "format ELF64 executable\n" +
 	"  mov rax, 60\n" +
 	"  syscall\n"
 
+const executableAsmHeaderNoReturnValue = "format ELF64 executable\n" +
+	"segment readable executable\n" +
+	"entry _start\n" +
+	"_start:\n" +
+	"  call main\n" +
+	"  mov rdi, 0\n" +
+	"  mov rax, 60\n" +
+	"  syscall\n"
+
 func (p *Program) Emit() string {
 	var builder strings.Builder
-	builder.WriteString(executableAsmHeader)
+	builder.WriteString(p.executableAsmHeader())
 
 	for _, function := range p.Functions {
 		builder.WriteString(function.Emit())
@@ -32,9 +50,10 @@ func (p *Program) Emit() string {
 }
 
 type Function struct {
-	StackOffset  int64
+	StackOffset    int64
-	Name         string
+	Name           string
-	Instructions []Instruction
+	HasReturnValue bool
+	Instructions   []Instruction
 }
 
 func (f *Function) Emit() string {

asm/amd64/codegen.go

@@ -32,6 +32,12 @@ func CgProgram(prog *ttir.Program) *Program {
 	newProgram = replacePseudo(newProgram)
 	newProgram = instructionFixup(newProgram)
 
+	for i, f := range newProgram.Functions {
+		if f.Name == "main" {
+			newProgram.MainFunction = &newProgram.Functions[i]
+		}
+	}
+
 	return &newProgram
 }
 
@@ -43,23 +49,28 @@ func cgFunction(f ttir.Function) Function {
 	}
 
 	return Function{
-		Name:         f.Name,
+		Name:           f.Name,
-		Instructions: newInstructions,
+		Instructions:   newInstructions,
+		HasReturnValue: f.HasReturnValue,
 	}
 }
 
 func cgInstruction(i ttir.Instruction) []Instruction {
 	switch i := i.(type) {
 	case *ttir.Ret:
-		return []Instruction{
+		if i.Op != nil {
-			&SimpleInstruction{
+			return []Instruction{
-				Opcode: Mov,
+				&SimpleInstruction{
-				Lhs:    AX,
+					Opcode: Mov,
-				Rhs:    toAsmOperand(i.Op),
+					Lhs:    AX,
-			},
+					Rhs:    toAsmOperand(i.Op),
-			&SimpleInstruction{
+				},
-				Opcode: Ret,
+				&SimpleInstruction{
-			},
+					Opcode: Ret,
+				},
+			}
+		} else {
+			return []Instruction{&SimpleInstruction{Opcode: Ret}}
 		}
 	case *ttir.Binary:
 		return cgBinary(i)
@@ -149,7 +160,7 @@ func rpFunction(f Function) Function {
 		newInstructions = append(newInstructions, rpInstruction(i, r))
 	}
 
-	return Function{Instructions: newInstructions, Name: f.Name, StackOffset: r.currentOffset}
+	return Function{Instructions: newInstructions, Name: f.Name, StackOffset: r.currentOffset, HasReturnValue: f.HasReturnValue}
 }
 
 func rpInstruction(i Instruction, r *replacePseudoPass) Instruction {
@@ -209,7 +220,7 @@ func fixupFunction(f Function) Function {
 		newInstructions = append(newInstructions, fixupInstruction(i)...)
 	}
 
-	return Function{Name: f.Name, Instructions: newInstructions, StackOffset: f.StackOffset}
+	return Function{Name: f.Name, Instructions: newInstructions, StackOffset: f.StackOffset, HasReturnValue: f.HasReturnValue}
 }
 
 func fixupInstruction(i Instruction) []Instruction {

tast/tast.go

@@ -111,3 +111,32 @@ func (be *BinaryExpression) TokenLiteral() string { return be.Token.Literal }
 func (be *BinaryExpression) String() string {
 	return fmt.Sprintf("(%s %s %s :> %s)", be.Lhs, be.Operator.SymbolString(), be.Rhs, be.ResultType.Name())
 }
+
+type BlockExpression struct {
+	Token            token.Token // The '{'
+	Expressions      []Expression
+	ReturnExpression Expression // A expression that does not end with a semicolon, there can only be one of those and it hast to be at the end
+	ReturnType       types.Type
+}
+
+func (be *BlockExpression) expressionNode() {}
+func (be *BlockExpression) Type() types.Type {
+	return be.ReturnType
+}
+func (be *BlockExpression) TokenLiteral() string { return be.Token.Literal }
+func (be *BlockExpression) String() string {
+	var builder strings.Builder
+
+	builder.WriteString("({\n")
+	for _, expr := range be.Expressions {
+		builder.WriteString("\t")
+		builder.WriteString(expr.String())
+		builder.WriteString(";\n")
+	}
+	if be.ReturnExpression != nil {
+		builder.WriteString(fmt.Sprintf("\t%s\n", be.ReturnExpression.String()))
+	}
+	builder.WriteString("})")
+
+	return builder.String()
+}

ttir/emit.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	"robaertschi.xyz/robaertschi/tt/tast"
+	"robaertschi.xyz/robaertschi/tt/types"
 )
 
 var uniqueId int64
@@ -31,8 +32,9 @@ func emitFunction(function *tast.FunctionDeclaration) *Function {
 	value, instructions := emitExpression(function.Body)
 	instructions = append(instructions, &Ret{Op: value})
 	return &Function{
-		Name:         function.Name,
+		Name:           function.Name,
-		Instructions: instructions,
+		Instructions:   instructions,
+		HasReturnValue: !function.ReturnType.IsSameType(types.Unit),
 	}
 }
 
@@ -56,6 +58,22 @@ func emitExpression(expr tast.Expression) (Operand, []Instruction) {
 			instructions = append(instructions, &Binary{Operator: expr.Operator, Lhs: lhsDst, Rhs: rhsDst, Dst: dst})
 			return dst, instructions
 		}
+	case *tast.BlockExpression:
+		instructions := []Instruction{}
+
+		for _, expr := range expr.Expressions {
+			_, insts := emitExpression(expr)
+			instructions = append(instructions, insts...)
+		}
+
+		var value Operand
+		if expr.ReturnExpression != nil {
+			dst, insts := emitExpression(expr.ReturnExpression)
+			value = dst
+			instructions = append(instructions, insts...)
+		}
+
+		return value, instructions
 	}
 	panic("unhandled tast.Expression case in ir emitter")
 }

ttir/ttir.go

@@ -20,8 +20,9 @@ func (p *Program) String() string {
 }
 
 type Function struct {
-	Name         string
+	Name           string
-	Instructions []Instruction
+	Instructions   []Instruction
+	HasReturnValue bool
 }
 
 func (f *Function) String() string {
@@ -40,11 +41,16 @@ type Instruction interface {
 }
 
 type Ret struct {
+	// Nullable, if it does not return anything
 	Op Operand
 }
 
 func (r *Ret) String() string {
-	return fmt.Sprintf("ret %s\n", r.Op)
+	if r.Op != nil {
+		return fmt.Sprintf("ret %s\n", r.Op)
+	} else {
+		return "ret\n"
+	}
 }
 func (r *Ret) instruction() {}
 

typechecker/check.go

@@ -85,6 +85,16 @@ func (c *Checker) checkExpression(expr tast.Expression) error {
 		}
 
 		return errors.Join(lhsErr, rhsErr, operandErr)
+	case *tast.BlockExpression:
+		errs := []error{}
+
+		for _, expr := range expr.Expressions {
+			errs = append(errs, c.checkExpression(expr))
+		}
+		if expr.ReturnExpression != nil {
+			errs = append(errs, c.checkExpression(expr.ReturnExpression))
+		}
+		return errors.Join(errs...)
 	}
-	return fmt.Errorf("unhandled expression in type checker")
+	return fmt.Errorf("unhandled expression %T in type checker", expr)
 }

typechecker/infer.go

@@ -60,6 +60,39 @@ func (c *Checker) inferExpression(expr ast.Expression) (tast.Expression, error)
 		}
 
 		return &tast.BinaryExpression{Lhs: lhs, Rhs: rhs, Operator: expr.Operator, Token: expr.Token, ResultType: resultType}, errors.Join(lhsErr, rhsErr)
+	case *ast.BlockExpression:
+		expressions := []tast.Expression{}
+		errs := []error{}
+
+		for _, expr := range expr.Expressions {
+			newExpr, err := c.inferExpression(expr)
+			if err != nil {
+				errs = append(errs, err)
+			} else {
+				expressions = append(expressions, newExpr)
+			}
+		}
+
+		var returnExpr tast.Expression
+		var returnType types.Type
+		if expr.ReturnExpression != nil {
+			expr, err := c.inferExpression(expr.ReturnExpression)
+			returnExpr = expr
+			if err != nil {
+				errs = append(errs, err)
+			} else {
+				returnType = returnExpr.Type()
+			}
+		} else {
+			returnType = types.Unit
+		}
+
+		return &tast.BlockExpression{
+			Token:            expr.Token,
+			Expressions:      expressions,
+			ReturnType:       returnType,
+			ReturnExpression: returnExpr,
+		}, errors.Join(errs...)
 	}
 	return nil, fmt.Errorf("unhandled expression in type inferer")
 }

types/types.go

@@ -15,11 +15,13 @@ type TypeId struct {
 }
 
 const (
-	I64Id int64 = iota
+	UnitId int64 = iota
+	I64Id
 	BoolId
 )
 
 var (
+	Unit = New(UnitId, "()")
 	I64  = New(I64Id, "i64")
 	Bool = New(BoolId, "bool")
 )