package main import ( "C" "go/format" "log" "sort" "strings" ) func goReservedWord(s string) bool { switch s { case "default", "const", "func", "var", "type", "len", "new", "copy", "import", "range", "string", "map", "int", "select", "ret": // not a language-reserved word, but a binding-reserved word return true default: return false } } func (p CppParameter) RenderTypeGo() string { if p.Pointer && p.ParameterType == "char" { return "string" } if p.ParameterType == "QString" { return "string" } if t, ok := p.QListOf(); ok { return "[]" + t.RenderTypeGo() } ret := "" if p.ByRef || p.Pointer { ret += "*" } switch p.ParameterType { case "char", "qint8", "signed char", "unsigned char", "uchar", "quint8": ret += "byte" // Strictly speaking, Go byte is unsigned and char may be signed case "short", "qint16": ret += "int16" case "ushort", "quint16", "unsigned short": ret += "uint16" case "long": // Windows ILP32 - 32-bits // Linux LP64 - 64-bits if C.sizeof_long == 4 { ret += "int32" } else { ret += "int64" } case "ulong", "unsigned long": if C.sizeof_long == 4 { ret += "uint32" } else { ret += "uint64" } case "unsigned int": ret += "uint" case "qint32": ret += "int32" case "quint32": ret += "uint32" case "qlonglong", "qint64", "long long": ret += "int64" case "qulonglong", "quint64", "unsigned long long": ret += "uint64" case "float": ret += "float32" case "double", "qreal": ret += "float64" case "qsizetype", "size_t", "qptrdiff", "ptrdiff_t": if C.sizeof_size_t == 4 { ret += "uint32" } else { ret += "uint64" } case "qintptr", "uintptr_t", "intptr_t", "quintptr": ret += "uintptr" default: if p.IsFlagType() { ret += "int" } else if strings.Contains(p.ParameterType, `::`) { if p.IsKnownEnum() { ret += cabiClassName(p.ParameterType) } else if p.IsEnum() { ret += "uintptr" } else { // Inner class ret += cabiClassName(p.ParameterType) } } else { // Do not transform this type ret += p.ParameterType } } return ret // ignore const } func (p CppParameter) parameterTypeCgo() string { if p.ParameterType == "QString" { return "C.char" } tmp := strings.Replace(p.RenderTypeCabi(), `*`, "", -1) if strings.HasPrefix(tmp, "const ") { tmp = tmp[6:] // Constness doesn't survive the CABI boundary } if strings.HasPrefix(tmp, "unsigned ") { tmp = "u" + tmp[9:] // Cgo uses uchar, uint instead of full name } if strings.HasPrefix(tmp, "signed ") { tmp = "s" + tmp[7:] // Cgo uses schar } tmp = strings.Replace(tmp, `long long`, `longlong`, -1) return "C." + strings.Replace(tmp, " ", "_", -1) } func emitParametersGo(params []CppParameter) string { tmp := make([]string, 0, len(params)) skipNext := false for i, p := range params { if IsArgcArgv(params, i) { skipNext = true tmp = append(tmp, "args []string") } else if skipNext { // Skip this parameter, already handled skipNext = false } else { // Ordinary parameter tmp = append(tmp, p.ParameterName+" "+p.RenderTypeGo()) } } return strings.Join(tmp, ", ") } type goFileState struct { imports map[string]struct{} } func (gfs *goFileState) emitParametersGo2CABIForwarding(m CppMethod) (preamble string, forwarding string) { tmp := make([]string, 0, len(m.Parameters)+2) if !m.IsStatic { tmp = append(tmp, "this.h") } skipNext := false for i, p := range m.Parameters { if IsArgcArgv(m.Parameters, i) { skipNext = true // QApplication constructor. Convert 'args' into Qt's wanted types // Qt has a warning in the docs saying these pointers must be valid // for the entire lifetype of QApplication, so, malloc + never free preamble += "// Convert []string to long-lived int& argc, char** argv, never call free()\n" preamble += "argc := (*C.int)(C.malloc(8))\n" preamble += "*argc = C.int(len(args))\n" preamble += "argv := (*[0xffff]*C.char)(C.malloc(C.size_t(8 * len(args))))\n" preamble += "for i := range args {\n" preamble += "argv[i] = C.CString(args[i])\n" preamble += "}\n" tmp = append(tmp, "argc, &argv[0]") } else if skipNext { // Skip this parameter, already handled skipNext = false } else if p.ParameterType == "QString" { // Go: convert string -> char* and len // CABI: convert char* and len -> real QString gfs.imports["unsafe"] = struct{}{} preamble += p.ParameterName + "_Cstring := C.CString(" + p.ParameterName + ")\n" preamble += "defer C.free(unsafe.Pointer(" + p.ParameterName + "_Cstring))\n" tmp = append(tmp, p.ParameterName+"_Cstring, C.size_t(len("+p.ParameterName+"))") // Second parameter cast to size_t projected type } else if listType, ok := p.QListOf(); ok { // QList // Go: convert T[] -> t* and len // CABI: create a real QList<> if listType.ParameterType == "QString" { // Combo gfs.imports["unsafe"] = struct{}{} preamble += "// For the C ABI, malloc two C arrays; raw char* pointers and their lengths\n" preamble += p.ParameterName + "_CArray := (*[0xffff]*" + listType.parameterTypeCgo() + ")(C.malloc(C.size_t(8 * len(" + p.ParameterName + "))))\n" preamble += p.ParameterName + "_Lengths := (*[0xffff]C.uint64_t)(C.malloc(C.size_t(8 * len(" + p.ParameterName + "))))\n" preamble += "defer C.free(unsafe.Pointer(" + p.ParameterName + "_CArray))\n" preamble += "defer C.free(unsafe.Pointer(" + p.ParameterName + "_Lengths))\n" preamble += "for i := range " + p.ParameterName + "{\n" preamble += "single_cstring := C.CString(" + p.ParameterName + "[i])\n" preamble += "defer C.free(unsafe.Pointer(single_cstring))\n" preamble += p.ParameterName + "_CArray[i] = single_cstring\n" preamble += p.ParameterName + "_Lengths[i] = (C.uint64_t)(len(" + p.ParameterName + "[i]))\n" preamble += "}\n" tmp = append(tmp, "&"+p.ParameterName+"_CArray[0], &"+p.ParameterName+"_Lengths[0], C.size_t(len("+p.ParameterName+"))") } else { preamble += "// For the C ABI, malloc a C array of raw pointers\n" if listType.QtClassType() { preamble += p.ParameterName + "_CArray := (*[0xffff]*" + listType.parameterTypeCgo() + ")(C.malloc(C.size_t(8 * len(" + p.ParameterName + "))))\n" } else { preamble += p.ParameterName + "_CArray := (*[0xffff]" + listType.parameterTypeCgo() + ")(C.malloc(C.size_t(8 * len(" + p.ParameterName + "))))\n" } preamble += "defer C.free(unsafe.Pointer(" + p.ParameterName + "_CArray))\n" preamble += "for i := range " + p.ParameterName + "{\n" if listType.QtClassType() { preamble += p.ParameterName + "_CArray[i] = " + p.ParameterName + "[i].cPointer()\n" } else { preamble += p.ParameterName + "_CArray[i] = (" + listType.parameterTypeCgo() + ")(" + p.ParameterName + "[i])\n" } preamble += "}\n" tmp = append(tmp, "&"+p.ParameterName+"_CArray[0], C.size_t(len("+p.ParameterName+"))") } } else if p.Pointer && p.ParameterType == "char" { // Single char* argument gfs.imports["unsafe"] = struct{}{} preamble += p.ParameterName + "_Cstring := C.CString(" + p.ParameterName + ")\n" preamble += "defer C.free(unsafe.Pointer(" + p.ParameterName + "_Cstring))\n" tmp = append(tmp, p.ParameterName+"_Cstring") } else if /*(p.Pointer || p.ByRef) &&*/ p.QtClassType() { // The C++ type is a pointer to Qt class // We want our functions to accept the Go wrapper type, and forward as cPointer() tmp = append(tmp, p.ParameterName+".cPointer()") } else if p.IntType() || p.ParameterType == "bool" { if p.Pointer || p.ByRef { gfs.imports["unsafe"] = struct{}{} tmp = append(tmp, "(*"+p.parameterTypeCgo()+")(unsafe.Pointer("+p.ParameterName+"))") // n.b. This may not work if the integer type conversion was wrong } else { tmp = append(tmp, "("+p.parameterTypeCgo()+")("+p.ParameterName+")") } } else { // Default tmp = append(tmp, p.ParameterName) } } if m.ReturnType.ParameterType == "QString" { tmp = append(tmp, "&_out, &_out_Strlen") } else if t, ok := m.ReturnType.QListOf(); ok { if t.ParameterType == "QString" { // Combo tmp = append(tmp, "&_out, &_out_Lengths, &_out_len") } else { tmp = append(tmp, "&_out, &_out_len") } } return preamble, strings.Join(tmp, ", ") } func emitGo(src *CppParsedHeader, headerName string) (string, error) { ret := strings.Builder{} ret.WriteString(`package qt /* #include "gen_` + headerName + `" #include */ import "C" %%_IMPORTLIBS_%% `) gfs := goFileState{ imports: map[string]struct{}{}, } for _, e := range src.Enums { goEnumName := cabiClassName(e.EnumName) ret.WriteString(` type ` + goEnumName + ` ` + parseSingleTypeString(e.UnderlyingType).RenderTypeGo() + ` const ( `) for _, ee := range e.Entries { ret.WriteString(cabiClassName(goEnumName+"::"+ee.EntryName) + " " + goEnumName + " = " + ee.EntryValue + "\n") } ret.WriteString("\n)\n\n") } for _, c := range src.Classes { goClassName := cabiClassName(c.ClassName) ret.WriteString(` type ` + goClassName + ` struct { h *C.` + goClassName + ` `) // Embed all inherited types to directly allow calling inherited methods for _, base := range c.Inherits { ret.WriteString("*" + base + "\n") } ret.WriteString(` } func (this *` + goClassName + `) cPointer() *C.` + goClassName + ` { if this == nil { return nil } return this.h } `) localInit := "h: h" for _, base := range c.Inherits { gfs.imports["unsafe"] = struct{}{} localInit += ", " + base + ": new" + cabiClassName(base) + "_U(unsafe.Pointer(h))" } ret.WriteString(` func new` + goClassName + `(h *C.` + goClassName + `) *` + goClassName + ` { if h == nil { return nil } return &` + goClassName + `{` + localInit + `} } `) // CGO types only exist within the same Go file, so other Go files can't // call this same private ctor function, unless it goes through unsafe.Pointer{}. // This is probably because C types can possibly violate the ODR whereas // that never happens in Go's type system. gfs.imports["unsafe"] = struct{}{} ret.WriteString(` func new` + goClassName + `_U(h unsafe.Pointer) *` + goClassName + ` { return new` + goClassName + `( (*C.` + goClassName + `)(h) ) } `) for i, ctor := range c.Ctors { preamble, forwarding := gfs.emitParametersGo2CABIForwarding(ctor) if ctor.LinuxOnly { gfs.imports["runtime"] = struct{}{} ret.WriteString(` // New` + goClassName + maybeSuffix(i) + ` constructs a new ` + c.ClassName + ` object. func New` + goClassName + maybeSuffix(i) + `(` + emitParametersGo(ctor.Parameters) + `) *` + goClassName + ` { if runtime.GOOS == "linux" { ` + preamble + ` ret := C.` + goClassName + `_new` + maybeSuffix(i) + `(` + forwarding + `) return new` + goClassName + `(ret) } else { panic("Unsupported OS") } } `) } else { ret.WriteString(` // New` + goClassName + maybeSuffix(i) + ` constructs a new ` + c.ClassName + ` object. func New` + goClassName + maybeSuffix(i) + `(` + emitParametersGo(ctor.Parameters) + `) *` + goClassName + ` { ` + preamble + ` ret := C.` + goClassName + `_new` + maybeSuffix(i) + `(` + forwarding + `) return new` + goClassName + `(ret) } `) } } for _, m := range c.Methods { preamble, forwarding := gfs.emitParametersGo2CABIForwarding(m) shouldReturn := "return " afterword := "" returnTypeDecl := m.ReturnType.RenderTypeGo() // FIXME handle byRef/const here too if m.ReturnType.ParameterType == "void" && !m.ReturnType.Pointer { shouldReturn = "" returnTypeDecl = "" } else if m.ReturnType.ParameterType == "void" && m.ReturnType.Pointer { returnTypeDecl = "interface{}" } else if m.ReturnType.ParameterType == "char" && m.ReturnType.Pointer { // Qt functions normally return QString - anything returning char* // is something like QByteArray.Data() where it returns an unsafe // internal pointer gfs.imports["unsafe"] = struct{}{} returnTypeDecl = "unsafe.Pointer" shouldReturn = "ret := " afterword += "return (unsafe.Pointer)(ret)\n" } else if m.ReturnType.ParameterType == "QString" { shouldReturn = "" returnTypeDecl = "string" gfs.imports["unsafe"] = struct{}{} preamble += "var _out *C.char = nil\n" preamble += "var _out_Strlen C.int = 0\n" // I think size_t is "better" but GoStringN() requires C.int afterword += "ret := C.GoStringN(_out, _out_Strlen)\n" afterword += "C.free(unsafe.Pointer(_out))\n" afterword += "return ret" } else if t, ok := m.ReturnType.QListOf(); ok { gfs.imports["unsafe"] = struct{}{} shouldReturn = "" returnTypeDecl = "[]" + t.RenderTypeGo() if t.ParameterType == "QString" { // Combo preamble += "var _out **C.char = nil\n" preamble += "var _out_Lengths *C.int = nil\n" preamble += "var _out_len C.size_t = 0\n" afterword += "ret := make([]string, int(_out_len))\n" afterword += "_outCast := (*[0xffff]*C.char)(unsafe.Pointer(_out)) // hey ya\n" afterword += "_out_LengthsCast := (*[0xffff]C.int)(unsafe.Pointer(_out_Lengths))\n" afterword += "for i := 0; i < int(_out_len); i++ {\n" afterword += "ret[i] = C.GoStringN(_outCast[i], _out_LengthsCast[i])\n" afterword += "}\n" afterword += "C.free(unsafe.Pointer(_out))\n" afterword += "return ret\n" } else { if t.QtClassType() { preamble += "var _out **" + t.parameterTypeCgo() + " = nil\n" } else { preamble += "var _out *" + t.parameterTypeCgo() + " = nil\n" } preamble += "var _out_len C.size_t = 0\n" afterword += "ret := make([]" + t.RenderTypeGo() + ", int(_out_len))\n" if t.QtClassType() { afterword += "_outCast := (*[0xffff]*" + t.parameterTypeCgo() + ")(unsafe.Pointer(_out)) // so fresh so clean\n" } else { afterword += "_outCast := (*[0xffff]" + t.parameterTypeCgo() + ")(unsafe.Pointer(_out)) // mrs jackson\n" } afterword += "for i := 0; i < int(_out_len); i++ {\n" if t.QtClassType() { if !t.Pointer { // new, but then dereference it afterword += "ret[i] = *new" + cabiClassName(t.ParameterType) + "(_outCast[i])\n" } else { afterword += "ret[i] = new" + cabiClassName(t.ParameterType) + "(_outCast[i])\n" } } else { // plain int type afterword += "ret[i] = (" + t.RenderTypeGo() + ")(_outCast[i])\n" } afterword += "}\n" afterword += "C.free(unsafe.Pointer(_out))\n" afterword += "return ret\n" } } else if m.ReturnType.QtClassType() { // Construct our Go type based on this inner CABI type shouldReturn = "ret := " if m.ReturnType.Pointer || m.ReturnType.ByRef { gfs.imports["unsafe"] = struct{}{} afterword = "return new" + cabiClassName(m.ReturnType.ParameterType) + "_U(unsafe.Pointer(ret))" } else { // This is return by value, but CABI has new'd it into a // heap type for us // To preserve Qt's approximate semantics, add a runtime // finalizer to automatically Delete once the type goes out // of Go scope returnTypeDecl = "*" + returnTypeDecl gfs.imports["runtime"] = struct{}{} afterword = "// Qt uses pass-by-value semantics for this type. Mimic with finalizer\n" afterword += "ret1 := new" + cabiClassName(m.ReturnType.ParameterType) + "(ret)\n" afterword += "runtime.SetFinalizer(ret1, func(ret2 *" + cabiClassName(m.ReturnType.ParameterType) + ") {\n" afterword += "ret2.Delete()\n" afterword += "runtime.KeepAlive(ret2.h)\n" afterword += "})\n" afterword += "return ret1\n" } } else if m.ReturnType.IntType() || m.ReturnType.ParameterType == "bool" { // Need to cast Cgo type to Go int type shouldReturn = "ret := " afterword += "return (" + m.ReturnType.RenderTypeGo() + ")(ret)\n" } receiverAndMethod := `(this *` + goClassName + `) ` + m.SafeMethodName() if m.IsStatic { receiverAndMethod = goClassName + `_` + m.SafeMethodName() } if m.LinuxOnly { gfs.imports["runtime"] = struct{}{} ret.WriteString(` func ` + receiverAndMethod + `(` + emitParametersGo(m.Parameters) + `) ` + returnTypeDecl + ` { if runtime.GOOS == "linux" { ` + preamble + shouldReturn + ` C.` + goClassName + `_` + m.SafeMethodName() + `(` + forwarding + `) ` + afterword + ` } else { panic("Unsupported OS") } } `) } else { ret.WriteString(` func ` + receiverAndMethod + `(` + emitParametersGo(m.Parameters) + `) ` + returnTypeDecl + ` { ` + preamble + shouldReturn + ` C.` + goClassName + `_` + m.SafeMethodName() + `(` + forwarding + `) ` + afterword + `} `) } // Add Connect() wrappers for signal functions if m.IsSignal && !m.HasHiddenParams { gfs.imports["unsafe"] = struct{}{} gfs.imports["runtime/cgo"] = struct{}{} ret.WriteString(`func (this *` + goClassName + `) On` + m.SafeMethodName() + `(slot func()) { var slotWrapper miqtCallbackFunc = func(argc C.int, args *C.void) { slot() } C.` + goClassName + `_connect_` + m.SafeMethodName() + `(this.h, unsafe.Pointer(uintptr(cgo.NewHandle(slotWrapper)))) } `) } } if c.CanDelete { ret.WriteString(` func (this *` + goClassName + `) Delete() { C.` + goClassName + `_Delete(this.h) } `) } } goSrc := ret.String() // Fixup imports if len(gfs.imports) > 0 { allImports := make([]string, 0, len(gfs.imports)) for k, _ := range gfs.imports { allImports = append(allImports, `"`+k+`"`) } sort.Strings(allImports) goSrc = strings.Replace(goSrc, `%%_IMPORTLIBS_%%`, "import (\n\t"+strings.Join(allImports, "\n\t")+"\n)", 1) } else { goSrc = strings.Replace(goSrc, `%%_IMPORTLIBS_%%`, "", 1) } // Run gofmt over the result formattedSrc, err := format.Source([]byte(goSrc)) if err != nil { log.Printf("gofmt failure: %v", err) formattedSrc = []byte(goSrc) } return string(formattedSrc), nil }