Implemented extern functions

examples/winapi/winapi.q

@@ -1,3 +1,7 @@
+extern user32 {
+	MessageBoxA(window *Any, text *Int8, title *Int8, type UInt)
+}
+
 main() {
 	title := "Title."
 	text := "Hi!"

lib/io/io.q

@@ -4,18 +4,18 @@ in(buffer []Int8) -> Int {
 	return sys.read(0, buffer, len(buffer))
 }
 
-out(message []Int8) -> Int {
-	return sys.write(1, message, len(message))
+out(buffer []Int8) -> Int {
+	return sys.write(1, buffer, len(buffer))
 }
 
-error(message []Int8) -> Int {
-	return sys.write(2, message, len(message))
+error(buffer []Int8) -> Int {
+	return sys.write(2, buffer, len(buffer))
 }
 
 read(fd Int, buffer []Int8) -> Int {
 	return sys.read(fd, buffer, len(buffer))
 }
 
-write(fd Int, message []Int8) -> Int {
-	return sys.write(fd, message, len(message))
+write(fd Int, buffer []Int8) -> Int {
+	return sys.write(fd, buffer, len(buffer))
 }

lib/sys/io_linux.q

@@ -1,9 +1,9 @@
-read(fd Int, address *Any, length Int) -> Int {
-	return syscall(0, fd, address, length)
+read(fd Int, buffer *Any, length Int) -> Int {
+	return syscall(0, fd, buffer, length)
 }
 
-write(fd Int, address *Any, length Int) -> Int {
-	return syscall(1, fd, address, length)
+write(fd Int, buffer *Any, length Int) -> Int {
+	return syscall(1, fd, buffer, length)
 }
 
 open(path *Any, flags Int, mode Int) -> Int {

lib/sys/io_mac.q

@@ -1,9 +1,9 @@
-read(fd Int, address *Any, length Int) -> Int {
-	return syscall(0x2000003, fd, address, length)
+read(fd Int, buffer *Any, length Int) -> Int {
+	return syscall(0x2000003, fd, buffer, length)
 }
 
-write(fd Int, address *Any, length Int) -> Int {
-	return syscall(0x2000004, fd, address, length)
+write(fd Int, buffer *Any, length Int) -> Int {
+	return syscall(0x2000004, fd, buffer, length)
 }
 
 open(path *Any, flags Int, mode Int) -> Int {

lib/sys/io_windows.q

@@ -1,10 +1,16 @@
-read(fd Int, address *Any, length Int) -> Int {
-	kernel32.ReadFile(fd, address, length)
+extern kernel32 {
+	GetStdHandle(handle Int) -> Int
+	WriteConsoleA(fd Int, buffer *Any, length Int, written *Int) -> Bool
+	ReadFile(fd Int, buffer *Any, length Int) -> Bool
+}
+
+read(fd Int, buffer *Any, length Int) -> Int {
+	kernel32.ReadFile(fd, buffer, length)
 	return length
 }
 
-write(fd Int, address *Any, length Int) -> Int {
+write(fd Int, buffer *Any, length Int) -> Int {
 	fd = kernel32.GetStdHandle(-10 - fd)
-	kernel32.WriteConsoleA(fd, address, length, 0)
+	kernel32.WriteConsoleA(fd, buffer, length, 0)
 	return length
 }

lib/sys/mem_windows.q

@@ -1,3 +1,8 @@
+extern kernel32 {
+	VirtualAlloc(address Int, length Int, flags Int, protection Int)
+	VirtualFree(address *Any, length Int, type Int) -> Bool
+}
+
 mmap(address Int, length Int, protection Int, flags Int) -> *Any {
 	return kernel32.VirtualAlloc(address, length, flags, protection)
 }

lib/sys/proc_windows.q

@@ -1,3 +1,7 @@
+extern kernel32 {
+	ExitProcess(code UInt)
+}
+
 exit(code Int) {
 	kernel32.ExitProcess(code)
 }

src/compiler/Compile.go

@@ -108,6 +108,10 @@ func CompileFunctions(functions map[string]*core.Function) {
 	wg := sync.WaitGroup{}
 
 	for _, function := range functions {
+		if function.IsExtern() {
+			continue
+		}
+
 		wg.Add(1)
 
 		go func() {

src/core/BeforeCall.go

@@ -0,0 +1,32 @@
+package core
+
+import (
+	"git.akyoto.dev/cli/q/src/cpu"
+	"git.akyoto.dev/cli/q/src/errors"
+	"git.akyoto.dev/cli/q/src/expression"
+	"git.akyoto.dev/cli/q/src/token"
+	"git.akyoto.dev/cli/q/src/types"
+)
+
+// BeforeCall loads the registers with the parameter values and checks that the types match with the function signature.
+func (f *Function) BeforeCall(fn *Function, parameters []*expression.Expression, registers []cpu.Register) error {
+	for i := len(parameters) - 1; i >= 0; i-- {
+		typ, err := f.ExpressionToRegister(parameters[i], registers[i])
+
+		if err != nil {
+			return err
+		}
+
+		if !types.Is(typ, fn.Input[i].Type) {
+			_, expectsPointer := fn.Input[i].Type.(*types.Pointer)
+
+			if expectsPointer && parameters[i].Token.Kind == token.Number && parameters[i].Token.Text(f.File.Bytes) == "0" {
+				continue
+			}
+
+			return errors.New(&errors.TypeMismatch{Encountered: typ.Name(), Expected: fn.Input[i].Type.Name(), ParameterName: fn.Input[i].Name}, f.File, parameters[i].Token.Position)
+		}
+	}
+
+	return nil
+}

src/core/CompileCall.go

@@ -5,7 +5,6 @@ import (
 
 	"git.akyoto.dev/cli/q/src/errors"
 	"git.akyoto.dev/cli/q/src/expression"
-	"git.akyoto.dev/cli/q/src/token"
 	"git.akyoto.dev/cli/q/src/types"
 	"git.akyoto.dev/cli/q/src/x86"
 )
@@ -48,22 +47,13 @@ func (f *Function) CompileCall(root *expression.Expression) ([]types.Type, error
 		name = nameNode.Token.Text(f.File.Bytes)
 	}
 
-	if pkg == "kernel32" || pkg == "user32" || pkg == "gdi32" || pkg == "comctl32" {
-		parameters := root.Children[1:]
-		registers := x86.WindowsInputRegisters[:len(parameters)]
+	fn, exists = f.Functions[pkg+"."+name]
 
-		for i := len(parameters) - 1; i >= 0; i-- {
-			_, err := f.ExpressionToRegister(parameters[i], registers[i])
+	if !exists {
+		return nil, errors.New(&errors.UnknownFunction{Name: name}, f.File, nameNode.Token.Position)
+	}
 
-			if err != nil {
-				return nil, err
-			}
-		}
-
-		f.DLLs = f.DLLs.Append(pkg, name)
-		f.DLLCall(fmt.Sprintf("%s.%s", pkg, name))
-		return nil, nil
-	} else if pkg != f.File.Package {
+	if pkg != f.File.Package && !fn.IsExtern() {
 		if f.File.Imports == nil {
 			return nil, errors.New(&errors.UnknownPackage{Name: pkg}, f.File, pkgNode.Token.Position)
 		}
@@ -77,36 +67,30 @@ func (f *Function) CompileCall(root *expression.Expression) ([]types.Type, error
 		imp.Used = true
 	}
 
-	fn, exists = f.Functions[pkg+"."+name]
-
-	if !exists {
-		return nil, errors.New(&errors.UnknownFunction{Name: name}, f.File, nameNode.Token.Position)
-	}
-
 	parameters := root.Children[1:]
 
 	if len(parameters) != len(fn.Input) {
 		return nil, errors.New(&errors.ParameterCountMismatch{Function: fn.Name, Count: len(parameters), ExpectedCount: len(fn.Input)}, f.File, nameNode.Token.End())
 	}
 
-	registers := f.CPU.Input[:len(parameters)]
-
-	for i := len(parameters) - 1; i >= 0; i-- {
-		typ, err := f.ExpressionToRegister(parameters[i], registers[i])
+	if fn.IsExtern() {
+		f.DLLs = f.DLLs.Append(pkg, name)
+		registers := x86.WindowsInputRegisters[:len(parameters)]
+		err := f.BeforeCall(fn, parameters, registers)
 
 		if err != nil {
 			return nil, err
 		}
 
-		if !types.Is(typ, fn.Input[i].Type) {
-			_, expectsPointer := fn.Input[i].Type.(*types.Pointer)
+		f.DLLCall(fmt.Sprintf("%s.%s", pkg, name))
+		return fn.OutputTypes, nil
+	}
 
-			if expectsPointer && parameters[i].Token.Kind == token.Number && parameters[i].Token.Text(f.File.Bytes) == "0" {
-				continue
-			}
+	registers := f.CPU.Input[:len(parameters)]
+	err := f.BeforeCall(fn, parameters, registers)
 
-			return nil, errors.New(&errors.TypeMismatch{Encountered: typ.Name(), Expected: fn.Input[i].Type.Name(), ParameterName: fn.Input[i].Name}, f.File, parameters[i].Token.Position)
-		}
+	if err != nil {
+		return nil, err
 	}
 
 	f.CallSafe(fn, registers)

src/core/IsExtern.go

@@ -0,0 +1,6 @@
+package core
+
+// IsExtern returns true if the function has no body.
+func (f *Function) IsExtern() bool {
+	return f.Body == nil
+}

src/core/ResolveTypes.go

@@ -19,6 +19,10 @@ func (f *Function) ResolveTypes() error {
 			return errors.New(&errors.UnknownType{Name: typeName}, f.File, param.tokens[1].Position)
 		}
 
+		if f.IsExtern() {
+			continue
+		}
+
 		uses := token.Count(f.Body, f.File.Bytes, token.Identifier, param.Name)
 
 		if uses == 0 && param.Name != "_" {
@@ -38,7 +42,7 @@ func (f *Function) ResolveTypes() error {
 		param.Type = types.ByName(typeName, f.Package, f.Structs)
 
 		if param.Type == nil {
-			return errors.New(&errors.UnknownType{Name: typeName}, f.File, param.tokens[1].Position)
+			return errors.New(&errors.UnknownType{Name: typeName}, f.File, param.tokens[0].Position)
 		}
 
 		f.OutputTypes = append(f.OutputTypes, param.Type)

src/errors/Common.go

@@ -9,6 +9,7 @@ var (
 	ExpectedIfBeforeElse       = &Base{"Expected an 'if' block before 'else'"}
 	ExpectedPackageName        = &Base{"Expected package name"}
 	ExpectedStructName         = &Base{"Expected struct name"}
+	ExpectedDLLName            = &Base{"Expected DLL name"}
 	InvalidNumber              = &Base{"Invalid number"}
 	InvalidExpression          = &Base{"Invalid expression"}
 	InvalidRune                = &Base{"Invalid rune"}

src/scanner/scanExtern.go

@@ -0,0 +1,54 @@
+package scanner
+
+import (
+	"git.akyoto.dev/cli/q/src/errors"
+	"git.akyoto.dev/cli/q/src/fs"
+	"git.akyoto.dev/cli/q/src/token"
+)
+
+// scanExtern scans a block of external function declarations.
+func (s *Scanner) scanExtern(file *fs.File, tokens token.List, i int) (int, error) {
+	i++
+
+	if tokens[i].Kind != token.Identifier {
+		return i, errors.New(errors.ExpectedDLLName, file, tokens[i].Position)
+	}
+
+	dllName := tokens[i].Text(file.Bytes)
+	i++
+
+	if tokens[i].Kind != token.BlockStart {
+		return i, errors.New(errors.MissingBlockStart, file, tokens[i].Position)
+	}
+
+	i++
+	closed := false
+
+	for i < len(tokens) {
+		if tokens[i].Kind == token.Identifier {
+			function, j, err := scanFunctionSignature(file, tokens, i, token.NewLine)
+
+			if err != nil {
+				return j, err
+			}
+
+			i = j
+			function.Package = dllName
+			function.UniqueName = dllName + "." + function.Name
+			s.functions <- function
+		}
+
+		if tokens[i].Kind == token.BlockEnd {
+			closed = true
+			break
+		}
+
+		i++
+	}
+
+	if !closed {
+		return i, errors.New(errors.MissingBlockEnd, file, tokens[i].Position)
+	}
+
+	return i, nil
+}

src/scanner/scanFile.go

@@ -37,6 +37,8 @@ func (s *Scanner) scanFile(path string, pkg string) error {
 			i, err = s.scanStruct(file, tokens, i)
 		case token.Identifier:
 			i, err = s.scanFunction(file, tokens, i)
+		case token.Extern:
+			i, err = s.scanExtern(file, tokens, i)
 		case token.EOF:
 			return nil
 		case token.Invalid:

src/scanner/scanFunction.go

@@ -1,7 +1,6 @@
 package scanner
 
 import (
-	"git.akyoto.dev/cli/q/src/core"
 	"git.akyoto.dev/cli/q/src/errors"
 	"git.akyoto.dev/cli/q/src/fs"
 	"git.akyoto.dev/cli/q/src/token"
@@ -9,84 +8,17 @@ import (
 
 // scanFunction scans a function.
 func (s *Scanner) scanFunction(file *fs.File, tokens token.List, i int) (int, error) {
+	function, i, err := scanFunctionSignature(file, tokens, i, token.BlockStart)
+
+	if err != nil {
+		return i, err
+	}
+
 	var (
-		groupLevel  = 0
-		blockLevel  = 0
-		nameStart   = i
-		paramsStart = -1
-		paramsEnd   = -1
-		bodyStart   = -1
-		typeStart   = -1
-		typeEnd     = -1
+		blockLevel = 0
+		bodyStart  = -1
 	)
 
-	i++
-
-	// Function parameters
-	for i < len(tokens) {
-		if tokens[i].Kind == token.GroupStart {
-			groupLevel++
-			i++
-
-			if groupLevel == 1 {
-				paramsStart = i
-			}
-
-			continue
-		}
-
-		if tokens[i].Kind == token.GroupEnd {
-			groupLevel--
-
-			if groupLevel < 0 {
-				return i, errors.New(errors.MissingGroupStart, file, tokens[i].Position)
-			}
-
-			if groupLevel == 0 {
-				paramsEnd = i
-				i++
-				break
-			}
-
-			i++
-			continue
-		}
-
-		if tokens[i].Kind == token.Invalid {
-			return i, errors.New(&errors.InvalidCharacter{Character: tokens[i].Text(file.Bytes)}, file, tokens[i].Position)
-		}
-
-		if tokens[i].Kind == token.EOF {
-			if groupLevel > 0 {
-				return i, errors.New(errors.MissingGroupEnd, file, tokens[i].Position)
-			}
-
-			if paramsStart == -1 {
-				return i, errors.New(errors.ExpectedFunctionParameters, file, tokens[i].Position)
-			}
-
-			return i, nil
-		}
-
-		if groupLevel > 0 {
-			i++
-			continue
-		}
-
-		return i, errors.New(errors.ExpectedFunctionParameters, file, tokens[i].Position)
-	}
-
-	// Return type
-	if i < len(tokens) && tokens[i].Kind == token.ReturnType {
-		typeStart = i + 1
-
-		for i < len(tokens) && tokens[i].Kind != token.BlockStart {
-			i++
-		}
-
-		typeEnd = i
-	}
-
 	// Function definition
 	for i < len(tokens) {
 		if tokens[i].Kind == token.ReturnType {
@@ -144,47 +76,7 @@ func (s *Scanner) scanFunction(file *fs.File, tokens token.List, i int) (int, er
 		return i, errors.New(errors.ExpectedFunctionDefinition, file, tokens[i].Position)
 	}
 
-	name := tokens[nameStart].Text(file.Bytes)
-	body := tokens[bodyStart:i]
-	function := core.NewFunction(file.Package, name, file, body)
-
-	if typeStart != -1 {
-		if tokens[typeStart].Kind == token.GroupStart && tokens[typeEnd-1].Kind == token.GroupEnd {
-			typeStart++
-			typeEnd--
-		}
-
-		outputTokens := tokens[typeStart:typeEnd]
-
-		err := outputTokens.Split(func(tokens token.List) error {
-			function.Output = append(function.Output, core.NewOutput(tokens))
-			return nil
-		})
-
-		if err != nil {
-			return i, err
-		}
-	}
-
-	parameters := tokens[paramsStart:paramsEnd]
-
-	err := parameters.Split(func(tokens token.List) error {
-		if len(tokens) == 0 {
-			return errors.New(errors.MissingParameter, file, parameters[0].Position)
-		}
-
-		if len(tokens) == 1 {
-			return errors.New(errors.MissingType, file, tokens[0].End())
-		}
-
-		function.Input = append(function.Input, core.NewInput(tokens))
-		return nil
-	})
-
-	if err != nil {
-		return i, err
-	}
-
+	function.Body = tokens[bodyStart:i]
 	s.functions <- function
 	i++
 	return i, nil

src/scanner/scanFunctionSignature.go

@@ -0,0 +1,125 @@
+package scanner
+
+import (
+	"git.akyoto.dev/cli/q/src/core"
+	"git.akyoto.dev/cli/q/src/errors"
+	"git.akyoto.dev/cli/q/src/fs"
+	"git.akyoto.dev/cli/q/src/token"
+)
+
+// scanFunctionSignature scans a function declaration without the body.
+func scanFunctionSignature(file *fs.File, tokens token.List, i int, delimiter token.Kind) (*core.Function, int, error) {
+	var (
+		groupLevel  = 0
+		nameStart   = i
+		paramsStart = -1
+		paramsEnd   = -1
+		typeStart   = -1
+		typeEnd     = -1
+	)
+
+	i++
+
+	// Function parameters
+	for i < len(tokens) {
+		if tokens[i].Kind == token.GroupStart {
+			groupLevel++
+			i++
+
+			if groupLevel == 1 {
+				paramsStart = i
+			}
+
+			continue
+		}
+
+		if tokens[i].Kind == token.GroupEnd {
+			groupLevel--
+
+			if groupLevel < 0 {
+				return nil, i, errors.New(errors.MissingGroupStart, file, tokens[i].Position)
+			}
+
+			if groupLevel == 0 {
+				paramsEnd = i
+				i++
+				break
+			}
+
+			i++
+			continue
+		}
+
+		if tokens[i].Kind == token.Invalid {
+			return nil, i, errors.New(&errors.InvalidCharacter{Character: tokens[i].Text(file.Bytes)}, file, tokens[i].Position)
+		}
+
+		if tokens[i].Kind == token.EOF {
+			if groupLevel > 0 {
+				return nil, i, errors.New(errors.MissingGroupEnd, file, tokens[i].Position)
+			}
+
+			if paramsStart == -1 {
+				return nil, i, errors.New(errors.ExpectedFunctionParameters, file, tokens[i].Position)
+			}
+
+			return nil, i, nil
+		}
+
+		if groupLevel > 0 {
+			i++
+			continue
+		}
+
+		return nil, i, errors.New(errors.ExpectedFunctionParameters, file, tokens[i].Position)
+	}
+
+	// Return type
+	if i < len(tokens) && tokens[i].Kind == token.ReturnType {
+		typeStart = i + 1
+
+		for i < len(tokens) && tokens[i].Kind != delimiter {
+			i++
+		}
+
+		typeEnd = i
+	}
+
+	name := tokens[nameStart].Text(file.Bytes)
+	function := core.NewFunction(file.Package, name, file, nil)
+
+	if typeStart != -1 {
+		if tokens[typeStart].Kind == token.GroupStart && tokens[typeEnd-1].Kind == token.GroupEnd {
+			typeStart++
+			typeEnd--
+		}
+
+		outputTokens := tokens[typeStart:typeEnd]
+
+		err := outputTokens.Split(func(tokens token.List) error {
+			function.Output = append(function.Output, core.NewOutput(tokens))
+			return nil
+		})
+
+		if err != nil {
+			return nil, i, err
+		}
+	}
+
+	parameters := tokens[paramsStart:paramsEnd]
+
+	err := parameters.Split(func(tokens token.List) error {
+		if len(tokens) == 0 {
+			return errors.New(errors.MissingParameter, file, parameters[0].Position)
+		}
+
+		if len(tokens) == 1 {
+			return errors.New(errors.MissingType, file, tokens[0].End())
+		}
+
+		function.Input = append(function.Input, core.NewInput(tokens))
+		return nil
+	})
+
+	return function, i, err
+}

src/token/Kind.go

@@ -66,6 +66,7 @@ const (
 	___KEYWORDS___                    // <keywords>
 	Assert                            // assert
 	Else                              // else
+	Extern                            // extern
 	If                                // if
 	Import                            // import
 	Loop                              // loop

src/token/Tokenize_test.go

@@ -25,13 +25,14 @@ func TestFunction(t *testing.T) {
 }
 
 func TestKeyword(t *testing.T) {
-	tokens := token.Tokenize([]byte("assert if import else loop return struct switch"))
+	tokens := token.Tokenize([]byte("assert if import else extern loop return struct switch"))
 
 	expected := []token.Kind{
 		token.Assert,
 		token.If,
 		token.Import,
 		token.Else,
+		token.Extern,
 		token.Loop,
 		token.Return,
 		token.Struct,

src/token/identifier.go

@@ -19,6 +19,8 @@ func identifier(tokens List, buffer []byte, i Position) (List, Position) {
 		kind = If
 	case "else":
 		kind = Else
+	case "extern":
+		kind = Extern
 	case "import":
 		kind = Import
 	case "loop":

src/types/ByName.go

@@ -31,6 +31,8 @@ func ByName(name string, pkg string, structs map[string]*Struct) Type {
 	switch name {
 	case "Any":
 		return Any
+	case "Bool":
+		return Bool
 	case "Int":
 		return Int
 	case "Int64":
@@ -47,6 +49,8 @@ func ByName(name string, pkg string, structs map[string]*Struct) Type {
 		return Float64
 	case "Float32":
 		return Float32
+	case "UInt":
+		return UInt
 	}
 
 	typ, exists := structs[pkg+"."+name]

src/types/Common.go

@@ -13,6 +13,8 @@ var (
 )
 
 var (
+	Bool  = Int
 	Int   = Int64
 	Float = Float64
+	UInt  = Int
 )

tests/errors/ExpectedDLLName.q

@@ -0,0 +1 @@
+extern {}

tests/errors_test.go

@@ -15,6 +15,7 @@ var errs = []struct {
 	ExpectedError error
 }{
 	{"EmptySwitch.q", errors.EmptySwitch},
+	{"ExpectedDLLName.q", errors.ExpectedDLLName},
 	{"ExpectedFunctionDefinition.q", errors.ExpectedFunctionDefinition},
 	{"ExpectedFunctionParameters.q", errors.ExpectedFunctionParameters},
 	{"ExpectedIfBeforeElse.q", errors.ExpectedIfBeforeElse},