Golang Func.Type方法代码示例

func (g *javaGen) genMethodInterfaceProxy(oName string, m *types.Func) {
	if !g.isSigSupported(m.Type()) {
		g.Printf("// skipped method %s with unsupported parameter or return types\n\n", oName)
		return
	}
	sig := m.Type().(*types.Signature)
	params := sig.Params()
	res := sig.Results()
	g.genInterfaceMethodSignature(m, oName, false)
	g.Indent()
	// Push a JNI reference frame with a conservative capacity of two for each per parameter (Seq.Ref and Seq.Object),
	// plus extra space for the receiver, the return value, and exception (if any).
	g.Printf("JNIEnv *env = go_seq_push_local_frame(%d);\n", 2*params.Len()+10)
	g.Printf("jobject o = go_seq_from_refnum(env, refnum, proxy_class_%s_%s, proxy_class_%s_%s_cons);\n", g.pkgPrefix, oName, g.pkgPrefix, oName)
	for i := 0; i < params.Len(); i++ {
		pn := paramName(params, i)
		g.genCToJava("_"+pn, pn, params.At(i).Type(), modeTransient)
	}
	if res.Len() > 0 && !isErrorType(res.At(0).Type()) {
		t := res.At(0).Type()
		g.Printf("%s res = (*env)->Call%sMethod(env, o, ", g.jniType(t), g.jniCallType(t))
	} else {
		g.Printf("(*env)->CallVoidMethod(env, o, ")
	}
	g.Printf("mid_%s_%s", oName, m.Name())
	for i := 0; i < params.Len(); i++ {
		g.Printf(", _%s", paramName(params, i))
	}
	g.Printf(");\n")
	var retName string
	if res.Len() > 0 {
		var rets []string
		t := res.At(0).Type()
		if !isErrorType(t) {
			g.genJavaToC("res", t, modeRetained)
			retName = "_res"
			rets = append(rets, retName)
		}
		if res.Len() == 2 || isErrorType(t) {
			g.Printf("jstring exc = go_seq_get_exception_message(env);\n")
			st := types.Typ[types.String]
			g.genJavaToC("exc", st, modeRetained)
			retName = "_exc"
			rets = append(rets, "_exc")
		}

		if res.Len() > 1 {
			g.Printf("cproxy%s_%s_%s_return sres = {\n", g.pkgPrefix, oName, m.Name())
			g.Printf("	%s\n", strings.Join(rets, ", "))
			g.Printf("};\n")
			retName = "sres"
		}
	}
	g.Printf("go_seq_pop_local_frame(env);\n")
	if retName != "" {
		g.Printf("return %s;\n", retName)
	}
	g.Outdent()
	g.Printf("}\n\n")
}

func (g *goGen) genFuncSignature(o *types.Func, objName string) {
	g.Printf("//export proxy%s_%s_%s\n", g.pkgPrefix, objName, o.Name())
	g.Printf("func proxy%s_%s_%s(", g.pkgPrefix, objName, o.Name())
	if objName != "" {
		g.Printf("refnum C.int32_t")
	}
	sig := o.Type().(*types.Signature)
	params := sig.Params()
	for i := 0; i < params.Len(); i++ {
		if objName != "" || i > 0 {
			g.Printf(", ")
		}
		p := params.At(i)
		g.Printf("param_%s C.%s", g.paramName(params, i), g.cgoType(p.Type()))
	}
	g.Printf(") ")
	res := sig.Results()
	if res.Len() > 0 {
		g.Printf("(")
		for i := 0; i < res.Len(); i++ {
			if i > 0 {
				g.Printf(", ")
			}
			g.Printf("C.%s", g.cgoType(res.At(i).Type()))
		}
		g.Printf(") ")
	}
	g.Printf("{\n")
}

func (w *Walker) emitFunc(f *types.Func) {
	sig := f.Type().(*types.Signature)
	if sig.Recv() != nil {
		panic("method considered a regular function: " + f.String())
	}
	w.emitf("func %s%s", f.Name(), w.signatureString(sig))
}

func (g *JavaGen) genConstructor(f *types.Func, n string, jcls bool) {
	g.Printf("public %s(", n)
	g.genFuncArgs(f, nil, false)
	g.Printf(") {\n")
	g.Indent()
	sig := f.Type().(*types.Signature)
	params := sig.Params()
	if jcls {
		g.Printf("super(")
		for i := 0; i < params.Len(); i++ {
			if i > 0 {
				g.Printf(", ")
			}
			g.Printf(g.paramName(params, i))
		}
		g.Printf(");\n")
	}
	g.Printf("this.ref = ")
	g.Printf("__%s(", f.Name())
	for i := 0; i < params.Len(); i++ {
		if i > 0 {
			g.Printf(", ")
		}
		g.Printf(g.paramName(params, i))
	}
	g.Printf(");\n")
	g.Outdent()
	g.Printf("}\n\n")
	g.Printf("private static native Seq.Ref __%s(", f.Name())
	g.genFuncArgs(f, nil, false)
	g.Printf(");\n\n")
}

// identicalSansNames compares two functions to check if their types are identical
// according to the names. e.g.
//   - It does not care if the names of the parameters or return values differ
//   - It does not care if the implementations of the types differ
func identicalSansNames(fa, fb *types.Func) bool {
	// must always succeed
	sigA := fa.Type().(*types.Signature)
	sigB := fb.Type().(*types.Signature)

	var (
		lenParams  = sigA.Params().Len()
		lenResults = sigA.Results().Len()
	)

	if sigB.Params().Len() != lenParams {
		return false
	}

	if sigB.Results().Len() != lenResults {
		return false
	}

	for i := 0; i < lenParams; i++ {
		if types.TypeString(sigA.Params().At(i).Type(), nil) != types.TypeString(sigB.Params().At(i).Type(), nil) {
			return false
		}
	}

	for i := 0; i < lenResults; i++ {
		if types.TypeString(sigA.Results().At(i).Type(), nil) != types.TypeString(sigB.Results().At(i).Type(), nil) {
			return false
		}
	}

	return true
}

func (g *javaGen) genFunc(o *types.Func, method bool) {
	if err := g.funcSignature(o, !method); err != nil {
		g.errorf("%v", err)
		return
	}
	sig := o.Type().(*types.Signature)
	res := sig.Results()

	g.Printf(" {\n")
	g.Indent()
	g.Printf("go.Seq _in = null;\n")
	g.Printf("go.Seq _out = null;\n")

	returnsError := false
	var resultType types.Type
	if res.Len() > 0 {
		if !isErrorType(res.At(0).Type()) {
			resultType = res.At(0).Type()
		}
		if res.Len() > 1 || isErrorType(res.At(0).Type()) {
			returnsError = true
		}
	}
	if resultType != nil || returnsError {
		g.Printf("_out = new go.Seq();\n")
	}
	if resultType != nil {
		t := g.javaType(resultType)
		g.Printf("%s _result;\n", t)
	}

	params := sig.Params()
	if method || params.Len() > 0 {
		g.Printf("_in = new go.Seq();\n")
	}
	if method {
		g.Printf("_in.writeRef(ref);\n")
	}
	for i := 0; i < params.Len(); i++ {
		p := params.At(i)
		g.Printf("_in.write%s;\n", seqWrite(p.Type(), paramName(params, i)))
	}
	g.Printf("Seq.send(DESCRIPTOR, CALL_%s, _in, _out);\n", o.Name())
	if resultType != nil {
		g.genRead("_result", "_out", resultType)
	}
	if returnsError {
		g.Printf(`String _err = _out.readString();
if (_err != null && !_err.isEmpty()) {
    throw new Exception(_err);
}
`)
	}
	if resultType != nil {
		g.Printf("return _result;\n")
	}
	g.Outdent()
	g.Printf("}\n\n")
}

func GoProto(fn *types.Func) (string, string, string) {
	pkgname := "package " + fn.Pkg().Name() + "\n"
	imports := ""
	signature := fn.Type().(*types.Signature)
	sig := strings.TrimPrefix(signature.String(), "func(")
	fnproto := "func " + fn.Name() + "(" + sig + "\n"
	return pkgname, imports, fnproto
}

func isCallable(t *types.Func) bool {
	// TODO(crawshaw): functions that are not implementable from
	// another language may still be callable (for example, a
	// returned value with an unexported type can be treated as
	// an opaque value by the caller). This restriction could be
	// lifted.
	return isImplementable(t.Type().(*types.Signature))
}

func (g *JavaGen) genMethodInterfaceProxy(oName string, m *types.Func) {
	if !g.isSigSupported(m.Type()) {
		g.Printf("// skipped method %s with unsupported parameter or return types\n\n", oName)
		return
	}
	sig := m.Type().(*types.Signature)
	params := sig.Params()
	res := sig.Results()
	g.genInterfaceMethodSignature(m, oName, false, g.paramName)
	g.Indent()
	g.Printf("JNIEnv *env = go_seq_push_local_frame(%d);\n", params.Len())
	g.Printf("jobject o = go_seq_from_refnum(env, refnum, proxy_class_%s_%s, proxy_class_%s_%s_cons);\n", g.pkgPrefix, oName, g.pkgPrefix, oName)
	for i := 0; i < params.Len(); i++ {
		pn := g.paramName(params, i)
		g.genCToJava("_"+pn, pn, params.At(i).Type(), modeTransient)
	}
	if res.Len() > 0 && !isErrorType(res.At(0).Type()) {
		t := res.At(0).Type()
		g.Printf("%s res = (*env)->Call%sMethod(env, o, ", g.jniType(t), g.jniCallType(t))
	} else {
		g.Printf("(*env)->CallVoidMethod(env, o, ")
	}
	g.Printf("mid_%s_%s", oName, m.Name())
	for i := 0; i < params.Len(); i++ {
		g.Printf(", _%s", g.paramName(params, i))
	}
	g.Printf(");\n")
	var retName string
	if res.Len() > 0 {
		var rets []string
		t := res.At(0).Type()
		if !isErrorType(t) {
			g.genJavaToC("res", t, modeRetained)
			retName = "_res"
			rets = append(rets, retName)
		}
		if res.Len() == 2 || isErrorType(t) {
			g.Printf("jobject exc = go_seq_get_exception(env);\n")
			errType := types.Universe.Lookup("error").Type()
			g.genJavaToC("exc", errType, modeRetained)
			retName = "_exc"
			rets = append(rets, "_exc")
		}

		if res.Len() > 1 {
			g.Printf("cproxy%s_%s_%s_return sres = {\n", g.pkgPrefix, oName, m.Name())
			g.Printf("	%s\n", strings.Join(rets, ", "))
			g.Printf("};\n")
			retName = "sres"
		}
	}
	g.Printf("go_seq_pop_local_frame(env);\n")
	if retName != "" {
		g.Printf("return %s;\n", retName)
	}
	g.Outdent()
	g.Printf("}\n\n")
}

func (g *ObjcGen) genFuncH(obj *types.Func) {
	if !g.isSigSupported(obj.Type()) {
		g.Printf("// skipped function %s with unsupported parameter or return types\n\n", obj.Name())
		return
	}
	if s := g.funcSummary(nil, obj); s != nil {
		g.Printf("FOUNDATION_EXPORT %s;\n", s.asFunc(g))
	}
}

func (g *JavaGen) genJNIFuncBody(o *types.Func, sName string, jm *java.Func, isjava bool) {
	sig := o.Type().(*types.Signature)
	res := sig.Results()
	if sName != "" {
		g.Printf("int32_t o = go_seq_to_refnum_go(env, __this__);\n")
	}
	params := sig.Params()
	first := 0
	if isjava && params.Len() > 0 && params.At(0).Name() == "this" {
		// Start after the implicit this argument.
		first = 1
		g.Printf("int32_t _%s = go_seq_to_refnum(env, __this__);\n", g.paramName(params, 0))
	}
	for i := first; i < params.Len(); i++ {
		name := g.paramName(params, i)
		g.genJavaToC(name, params.At(i).Type(), modeTransient)
	}
	resPrefix := ""
	if res.Len() > 0 {
		if res.Len() == 1 {
			g.Printf("%s r0 = ", g.cgoType(res.At(0).Type()))
		} else {
			resPrefix = "res."
			g.Printf("struct proxy%s_%s_%s_return res = ", g.pkgPrefix, sName, o.Name())
		}
	}
	g.Printf("proxy%s_%s_%s(", g.pkgPrefix, sName, o.Name())
	if sName != "" {
		g.Printf("o")
	}
	// Pass all arguments, including the implicit this argument.
	for i := 0; i < params.Len(); i++ {
		if i > 0 || sName != "" {
			g.Printf(", ")
		}
		g.Printf("_%s", g.paramName(params, i))
	}
	g.Printf(");\n")
	for i := first; i < params.Len(); i++ {
		g.genRelease(g.paramName(params, i), params.At(i).Type(), modeTransient)
	}
	for i := 0; i < res.Len(); i++ {
		tn := fmt.Sprintf("_r%d", i)
		t := res.At(i).Type()
		g.genCToJava(tn, fmt.Sprintf("%sr%d", resPrefix, i), t, modeRetained)
	}
	// Go backwards so that any exception is thrown before
	// the return.
	for i := res.Len() - 1; i >= 0; i-- {
		t := res.At(i).Type()
		if !isErrorType(t) {
			g.Printf("return _r%d;\n", i)
		} else {
			g.Printf("go_seq_maybe_throw_exception(env, _r%d);\n", i)
		}
	}
}

func (b *Builder) addFunction(u types.Universe, useName *types.Name, in *tc.Func) *types.Type {
	name := tcFuncNameToName(in.String())
	if useName != nil {
		name = *useName
	}
	out := u.Function(name)
	out.Kind = types.DeclarationOf
	out.Underlying = b.walkType(u, nil, in.Type())
	return out
}

func (g *goGen) genFunc(o *types.Func) {
	if !g.isSigSupported(o.Type()) {
		g.Printf("// skipped function %s with unsupported parameter or result types\n", o.Name())
		return
	}
	g.genFuncSignature(o, "")
	g.Indent()
	g.genFuncBody(o, g.pkgName(g.Pkg))
	g.Outdent()
	g.Printf("}\n\n")
}

func (p *printer) printFunc(recvType types.Type, obj *types.Func) {
	p.print("func ")
	sig := obj.Type().(*types.Signature)
	if recvType != nil {
		p.print("(")
		p.writeType(p.pkg, recvType)
		p.print(") ")
	}
	p.print(obj.Name())
	p.writeSignature(p.pkg, sig)
}

func (g *javaGen) genFuncSignature(o *types.Func, static, header bool) {
	sig := o.Type().(*types.Signature)
	res := sig.Results()

	var returnsError bool
	var ret string
	switch res.Len() {
	case 2:
		if !isErrorType(res.At(1).Type()) {
			g.errorf("second result value must be of type error: %s", o)
			return
		}
		returnsError = true
		ret = g.javaType(res.At(0).Type())
	case 1:
		if isErrorType(res.At(0).Type()) {
			returnsError = true
			ret = "void"
		} else {
			ret = g.javaType(res.At(0).Type())
		}
	case 0:
		ret = "void"
	default:
		g.errorf("too many result values: %s", o)
		return
	}

	g.Printf("public ")
	if static {
		g.Printf("static ")
	}
	if !header {
		g.Printf("native ")
	}
	oName := o.Name()
	g.Printf("%s %s(", ret, oName)
	params := sig.Params()
	for i := 0; i < params.Len(); i++ {
		if i > 0 {
			g.Printf(", ")
		}
		v := sig.Params().At(i)
		name := paramName(params, i)
		jt := g.javaType(v.Type())
		g.Printf("%s %s", jt, name)
	}
	g.Printf(")")
	if returnsError {
		g.Printf(" throws Exception")
	}
	g.Printf(";\n")
}