Improved Windows support

src/asm/Finalize.go

@@ -8,12 +8,13 @@ import (
 
 	"git.akyoto.dev/cli/q/src/arch/x64"
 	"git.akyoto.dev/cli/q/src/config"
+	"git.akyoto.dev/cli/q/src/dll"
 	"git.akyoto.dev/cli/q/src/exe"
 	"git.akyoto.dev/cli/q/src/sizeof"
 )
 
 // Finalize generates the final machine code.
-func (a Assembler) Finalize() ([]byte, []byte) {
+func (a Assembler) Finalize(dlls dll.List) ([]byte, []byte) {
 	var (
 		code         = make([]byte, 0, len(a.Instructions)*8)
 		data         []byte
@@ -21,6 +22,7 @@ func (a Assembler) Finalize() ([]byte, []byte) {
 		dataLabels   map[string]Address
 		codePointers []*Pointer
 		dataPointers []*Pointer
+		dllPointers  []*Pointer
 	)
 
 	for _, x := range a.Instructions {
@@ -114,7 +116,7 @@ func (a Assembler) Finalize() ([]byte, []byte) {
 		case CALL_AT:
 			code = x64.CallAtAddress(code, 0x00_00_00_00)
 			size := 4
-			// label := x.Data.(*Label)
+			label := x.Data.(*Label)
 
 			pointer := &Pointer{
 				Position: Address(len(code) - size),
@@ -123,12 +125,11 @@ func (a Assembler) Finalize() ([]byte, []byte) {
 			}
 
 			pointer.Resolve = func() Address {
-				destination := Address(0x1038)
+				index := dlls.Index("kernel32.dll", label.Name)
-				distance := destination - (pointer.Position + Address(pointer.Size))
+				return Address(index * 8)
-				return Address(distance)
 			}
 
-			codePointers = append(codePointers, pointer)
+			dllPointers = append(dllPointers, pointer)
 
 		case COMMENT:
 			continue
@@ -365,5 +366,12 @@ restart:
 		binary.LittleEndian.PutUint32(slice, uint32(address))
 	}
 
+	for _, pointer := range dllPointers {
+		destination := Address(0x3000) + pointer.Resolve()
+		address := destination - Address(config.CodeOffset+pointer.Position+Address(pointer.Size))
+		slice := code[pointer.Position : pointer.Position+4]
+		binary.LittleEndian.PutUint32(slice, uint32(address))
+	}
+
 	return code, data
 }

src/compiler/Result.go

@@ -77,7 +77,7 @@ func (r *Result) finalize() ([]byte, []byte) {
 		final.Label(asm.CALL_AT, "ExitProcess")
 	}
 
-	code, data := final.Finalize()
+	code, data := final.Finalize(windows.DLLs)
 	return code, data
 }
 
@@ -154,24 +154,7 @@ func write(writer io.Writer, code []byte, data []byte) error {
 	case "mac":
 		macho.Write(buffer, code, data)
 	case "windows":
-		dlls := []pe.DLL{
+		pe.Write(buffer, code, data, windows.DLLs)
-			{
-				Name: "kernel32.dll",
-				Functions: []string{
-					"ExitProcess",
-					"GetStdHandle",
-					"WriteFile",
-				},
-			},
-			{
-				Name: "user32.dll",
-				Functions: []string{
-					"MessageBoxA",
-				},
-			},
-		}
-
-		pe.Write(buffer, code, data, dlls)
 	default:
 		return fmt.Errorf("unsupported platform '%s'", config.TargetOS)
 	}

src/dll/DLL.go

@@ -1,4 +1,4 @@
-package pe
+package dll
 
 type DLL struct {
 	Name      string

src/dll/List.go

@@ -0,0 +1,24 @@
+package dll
+
+// List is a slice of DLLs.
+type List []DLL
+
+// Index returns the position of the given function name.
+func (list List) Index(dllName string, funcName string) int {
+	index := 0
+
+	for _, dll := range list {
+		if dll.Name != dllName {
+			index += len(dll.Functions) + 1
+			continue
+		}
+
+		for i, fn := range dll.Functions {
+			if fn == funcName {
+				return index + i
+			}
+		}
+	}
+
+	return -1
+}

src/exe/pe/EXE.go

@@ -6,6 +6,7 @@ import (
 	"io"
 
 	"git.akyoto.dev/cli/q/src/config"
+	"git.akyoto.dev/cli/q/src/dll"
 	"git.akyoto.dev/cli/q/src/exe"
 )
 
@@ -18,56 +19,71 @@ type EXE struct {
 }
 
 // Write writes the EXE file to the given writer.
-func Write(writer io.Writer, code []byte, data []byte, dlls []DLL) {
+func Write(writer io.Writer, code []byte, data []byte, dlls dll.List) {
-	NumSections := 2
+	if len(data) == 0 {
+		data = []byte{0}
+	}
+
+	NumSections := 3
 	HeaderEnd := DOSHeaderSize + NTHeaderSize + OptionalHeader64Size + SectionHeaderSize*NumSections
 	codeStart, codePadding := exe.Align(HeaderEnd, config.Align)
 	dataStart, dataPadding := exe.Align(codeStart+len(code), config.Align)
+	importsStart, importsPadding := exe.Align(dataStart+len(data), config.Align)
 
+	imports := make([]uint64, 0)
+	dllData := make([]byte, 0)
 	dllImports := []DLLImport{}
 
-	for _, dll := range dlls {
+	for _, library := range dlls {
-		dllAddresses := []uint64{}
+		functionsStart := len(imports) * 8
-		dllNamePos := len(data)
+		dllNamePos := len(dllData)
-		data = append(data, dll.Name...)
+		dllData = append(dllData, library.Name...)
-		data = append(data, 0x00)
+		dllData = append(dllData, 0x00)
-
-		for _, f := range dll.Functions {
-			pos := len(data)
-			data = append(data, 0x00, 0x00)
-			data = append(data, f...)
-			data = append(data, 0x00)
-
-			if len(data)&1 != 0 {
-				data = append(data, 0x00) // align the next entry on an even boundary
-			}
-
-			dllAddresses = append(dllAddresses, uint64(dataStart+pos))
-		}
-
-		dllAddresses = append(dllAddresses, 0)
-
-		// Add the address table to the data section
-		functionAddressesStart := dataStart + len(data)
-		data, _ = binary.Append(data, binary.LittleEndian, &dllAddresses)
 
 		dllImports = append(dllImports, DLLImport{
-			RvaFunctionNameList:    uint32(functionAddressesStart),
+			RvaFunctionNameList:    uint32(importsStart + functionsStart),
 			TimeDateStamp:          0,
 			ForwarderChain:         0,
-			RvaModuleName:          uint32(dataStart + dllNamePos),
+			RvaModuleName:          uint32(dllNamePos),
-			RvaFunctionAddressList: uint32(functionAddressesStart),
+			RvaFunctionAddressList: uint32(importsStart + functionsStart),
 		})
+
+		for _, fn := range library.Functions {
+			if len(dllData)&1 != 0 {
+				dllData = append(dllData, 0x00) // align the next entry on an even boundary
+			}
+
+			offset := len(dllData)
+			dllData = append(dllData, 0x00, 0x00)
+			dllData = append(dllData, fn...)
+			dllData = append(dllData, 0x00)
+
+			imports = append(imports, uint64(offset))
+		}
+
+		imports = append(imports, 0)
+	}
+
+	dllDataStart := importsStart + len(imports)*8
+
+	for i := range imports {
+		if imports[i] == 0 {
+			continue
+		}
+
+		imports[i] += uint64(dllDataStart)
+	}
+
+	for i := range dllImports {
+		dllImports[i].RvaModuleName += uint32(dllDataStart)
 	}
 
 	dllImports = append(dllImports, DLLImport{}) // a zeroed structure marks the end of the list
+	importDirectoryStart := dllDataStart + len(dllData)
+	importDirectorySize := DLLImportSize * len(dllImports)
 
-	// Add imports to the data section
+	importSectionSize := len(imports)*8 + len(dllData) + importDirectorySize
-	importsStart := dataStart + len(data)
+	imageSize := importsStart + importSectionSize
-	importsSize := DLLImportSize * len(dllImports)
-	data, _ = binary.Append(data, binary.LittleEndian, &dllImports)
-
-	imageSize := dataStart + len(data)
 	imageSize, _ = exe.Align(imageSize, config.Align)
 
 	pe := &EXE{
@@ -117,8 +133,7 @@ func Write(writer io.Writer, code []byte, data []byte, dlls []DLL) {
 			NumberOfRvaAndSizes:         16,
 			DataDirectory: [16]DataDirectory{
 				{VirtualAddress: 0, Size: 0},
-				{VirtualAddress: uint32(importsStart), Size: uint32(importsSize)}, // RVA of the imported function table
+				{VirtualAddress: uint32(importDirectoryStart), Size: uint32(importDirectorySize)}, // RVA of the imported function table
-				{VirtualAddress: 0, Size: 0},
 				{VirtualAddress: 0, Size: 0},
 				{VirtualAddress: 0, Size: 0},
 				{VirtualAddress: 0, Size: 0},
@@ -129,6 +144,7 @@ func Write(writer io.Writer, code []byte, data []byte, dlls []DLL) {
 				{VirtualAddress: 0, Size: 0},
 				{VirtualAddress: 0, Size: 0},
 				{VirtualAddress: 0, Size: 0},
+				{VirtualAddress: uint32(importsStart), Size: uint32(len(imports) * 8)}, // RVA of the import address table
 				{VirtualAddress: 0, Size: 0},
 				{VirtualAddress: 0, Size: 0},
 				{VirtualAddress: 0, Size: 0},
@@ -151,6 +167,14 @@ func Write(writer io.Writer, code []byte, data []byte, dlls []DLL) {
 				RawAddress:      uint32(dataStart),
 				Characteristics: IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ,
 			},
+			{
+				Name:            [8]byte{'.', 'i', 'd', 'a', 't', 'a'},
+				VirtualSize:     uint32(importSectionSize),
+				VirtualAddress:  uint32(importsStart),
+				RawSize:         uint32(importSectionSize),
+				RawAddress:      uint32(importsStart),
+				Characteristics: IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ,
+			},
 		},
 	}
 
@@ -163,4 +187,8 @@ func Write(writer io.Writer, code []byte, data []byte, dlls []DLL) {
 	writer.Write(code)
 	writer.Write(bytes.Repeat([]byte{0x00}, int(dataPadding)))
 	writer.Write(data)
+	writer.Write(bytes.Repeat([]byte{0x00}, int(importsPadding)))
+	binary.Write(writer, binary.LittleEndian, &imports)
+	binary.Write(writer, binary.LittleEndian, &dllData)
+	binary.Write(writer, binary.LittleEndian, &dllImports)
 }

src/os/windows/DLLs.go

@@ -0,0 +1,21 @@
+package windows
+
+import "git.akyoto.dev/cli/q/src/dll"
+
+// Temporary fix...
+var DLLs = dll.List{
+	{
+		Name: "kernel32.dll",
+		Functions: []string{
+			"ExitProcess",
+			"GetStdHandle",
+			"WriteFile",
+		},
+	},
+	{
+		Name: "user32.dll",
+		Functions: []string{
+			"MessageBoxA",
+		},
+	},
+}