//
// parameter.cs: Parameter definition.
//
// Author: Miguel de Icaza (miguel@gnu.org)
//
// Licensed under the terms of the GNU GPL
//
// (C) 2001 Ximian, Inc (http://www.ximian.com)
//
//
//
using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Collections;
using System.Text;
namespace Mono.CSharp {
///
/// Abstract Base class for parameters of a method.
///
public abstract class ParameterBase : Attributable {
protected ParameterBuilder builder;
public readonly Location Location;
public ParameterBase (Attributes attrs, Location loc)
: base (attrs)
{
Location = loc;
}
public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
{
if (a.Type == TypeManager.marshal_as_attr_type) {
UnmanagedMarshal marshal = a.GetMarshal (this);
if (marshal != null) {
builder.SetMarshal (marshal);
}
return;
}
if (a.Type.IsSubclassOf (TypeManager.security_attr_type)) {
a.Error_InvalidSecurityParent ();
return;
}
builder.SetCustomAttribute (cb);
}
public override bool IsClsComplianceRequired(DeclSpace ds)
{
return false;
}
}
///
/// Class for applying custom attributes on the return type
///
public class ReturnParameter : ParameterBase {
public ReturnParameter (MethodBuilder mb, Location location):
base (null, location)
{
try {
builder = mb.DefineParameter (0, ParameterAttributes.None, "");
}
catch (ArgumentOutOfRangeException) {
Report.RuntimeMissingSupport (Location, "custom attributes on the return type");
}
}
public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
{
if (a.Type == TypeManager.cls_compliant_attribute_type) {
Report.Warning (3023, 1, a.Location, "CLSCompliant attribute has no meaning when applied to return types. Try putting it on the method instead");
}
// This occurs after Warning -28
if (builder == null)
return;
base.ApplyAttributeBuilder (a, cb);
}
public override AttributeTargets AttributeTargets {
get {
return AttributeTargets.ReturnValue;
}
}
///
/// Is never called
///
public override string[] ValidAttributeTargets {
get {
return null;
}
}
}
///
/// Class for applying custom attributes on the implicit parameter type
/// of the 'set' method in properties, and the 'add' and 'remove' methods in events.
///
public class ImplicitParameter : ParameterBase {
public ImplicitParameter (MethodBuilder mb, Location loc):
base (null, loc)
{
builder = mb.DefineParameter (1, ParameterAttributes.None, "");
}
public override AttributeTargets AttributeTargets {
get {
return AttributeTargets.Parameter;
}
}
///
/// Is never called
///
public override string[] ValidAttributeTargets {
get {
return null;
}
}
}
///
/// Represents a single method parameter
///
public class Parameter : ParameterBase {
[Flags]
public enum Modifier : byte {
NONE = 0,
REF = 1,
OUT = 2,
PARAMS = 4,
// This is a flag which says that it's either REF or OUT.
ISBYREF = 8,
ARGLIST = 16
}
static string[] attribute_targets = new string [] { "param" };
public Expression TypeName;
public readonly Modifier ModFlags;
public readonly string Name;
Type parameter_type;
EmitContext ec; // because ApplyAtrribute doesn't have ec
public Parameter (Expression type, string name, Modifier mod, Attributes attrs, Location loc)
: base (attrs, loc)
{
Name = name;
ModFlags = mod;
TypeName = type;
}
public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
{
if (a.Type == TypeManager.in_attribute_type && Attributes == ParameterAttributes.Out) {
Report.Error (36, a.Location, "An out parameter cannot have the `In' attribute");
return;
}
if (a.Type == TypeManager.param_array_type) {
Report.Error (674, a.Location, "Do not use `System.ParamArrayAttribute'. Use the `params' keyword instead");
return;
}
if (a.Type == TypeManager.out_attribute_type && (ModFlags & Modifier.REF) != 0 &&
!OptAttributes.Contains (TypeManager.in_attribute_type, ec)) {
Report.Error (662, a.Location,
"Cannot specify only `Out' attribute on a ref parameter. Use both `In' and `Out' attributes or neither");
return;
}
if (a.Type == TypeManager.cls_compliant_attribute_type) {
Report.Warning (3022, 1, a.Location, "CLSCompliant attribute has no meaning when applied to parameters. Try putting it on the method instead");
}
base.ApplyAttributeBuilder (a, cb);
}
//
// Resolve is used in method definitions
//
public bool Resolve (EmitContext ec)
{
this.ec = ec;
TypeExpr texpr = TypeName.ResolveAsTypeTerminal (ec, false);
if (texpr == null)
return false;
parameter_type = texpr.ResolveType (ec);
if (parameter_type.IsAbstract && parameter_type.IsSealed) {
Report.Error (721, Location, "`{0}': static types cannot be used as parameters", GetSignatureForError ());
return false;
}
if (parameter_type == TypeManager.void_type){
Report.Error (1536, Location, "Invalid parameter type 'void'");
return false;
}
if ((ModFlags & Parameter.Modifier.ISBYREF) != 0){
if (parameter_type == TypeManager.typed_reference_type ||
parameter_type == TypeManager.arg_iterator_type){
Report.Error (1601, Location, "Method or delegate parameter cannot be of type `{0}'",
GetSignatureForError ());
return false;
}
}
return parameter_type != null;
}
public Type ExternalType ()
{
if ((ModFlags & Parameter.Modifier.ISBYREF) != 0)
return TypeManager.GetReferenceType (parameter_type);
return parameter_type;
}
public Type ParameterType {
get {
return parameter_type;
}
}
public ParameterAttributes Attributes {
get {
int flags = ((int) ModFlags) & ~((int) Parameter.Modifier.ISBYREF);
switch ((Modifier) flags) {
case Modifier.NONE:
return ParameterAttributes.None;
case Modifier.REF:
return ParameterAttributes.None;
case Modifier.OUT:
return ParameterAttributes.Out;
case Modifier.PARAMS:
return 0;
}
return ParameterAttributes.None;
}
}
public override AttributeTargets AttributeTargets {
get {
return AttributeTargets.Parameter;
}
}
///
/// Returns the signature for this parameter evaluating it on the
/// @tc context
///
public string GetSignature (EmitContext ec)
{
if (parameter_type == null){
if (!Resolve (ec))
return null;
}
return ExternalType ().FullName;
}
public string GetSignatureForError ()
{
string type_name;
if (parameter_type != null)
type_name = TypeManager.CSharpName (parameter_type);
else if (TypeName.Type != null)
type_name = TypeManager.CSharpName (TypeName.Type);
else
type_name = TypeName.ToString ();
string mod = GetModifierSignature (ModFlags);
if (mod.Length > 0)
return String.Concat (mod, " ", type_name);
return type_name;
}
public static string GetModifierSignature (Modifier mod)
{
switch (mod & unchecked (~Modifier.ISBYREF)) {
case Modifier.OUT:
return "out";
case Modifier.PARAMS:
return "params";
case Modifier.REF:
return "ref";
case Modifier.ARGLIST:
return "__arglist";
default:
return "";
}
}
public void DefineParameter (EmitContext ec, MethodBuilder mb, ConstructorBuilder cb, int index)
{
ParameterAttributes par_attr = Attributes;
if (mb == null)
builder = cb.DefineParameter (index, par_attr, Name);
else
builder = mb.DefineParameter (index, par_attr, Name);
if (OptAttributes != null) {
OptAttributes.Emit (ec, this);
}
}
public override string[] ValidAttributeTargets {
get {
return attribute_targets;
}
}
}
///
/// Represents the methods parameters
///
public class Parameters {
public Parameter [] FixedParameters;
public readonly Parameter ArrayParameter;
public readonly bool HasArglist;
string signature;
Type [] types;
static Parameters empty_parameters;
public Parameters (Parameter [] fixed_parameters, Parameter array_parameter)
{
FixedParameters = fixed_parameters;
ArrayParameter = array_parameter;
}
public Parameters (Parameter [] fixed_parameters, bool has_arglist)
{
FixedParameters = fixed_parameters;
HasArglist = has_arglist;
}
///
/// This is used to reuse a set of empty parameters, because they
/// are common
///
public static Parameters EmptyReadOnlyParameters {
get {
if (empty_parameters == null)
empty_parameters = new Parameters (null, null);
return empty_parameters;
}
}
public bool Empty {
get {
return (FixedParameters == null) && (ArrayParameter == null);
}
}
public void ComputeSignature (EmitContext ec)
{
signature = "";
if (FixedParameters != null){
for (int i = 0; i < FixedParameters.Length; i++){
Parameter par = FixedParameters [i];
signature += par.GetSignature (ec);
}
}
//
// Note: as per the spec, the `params' arguments (ArrayParameter)
// are not used in the signature computation for a method
//
}
void Error_DuplicateParameterName (string name, Location loc)
{
Report.Error (
100, loc, "The parameter name `" + name + "' is a duplicate");
}
public bool VerifyArgs ()
{
int count;
int i, j;
if (FixedParameters == null)
return true;
count = FixedParameters.Length;
string array_par_name = ArrayParameter != null ? ArrayParameter.Name : null;
for (i = 0; i < count; i++){
string base_name = FixedParameters [i].Name;
for (j = i + 1; j < count; j++){
if (base_name != FixedParameters [j].Name)
continue;
Error_DuplicateParameterName (base_name,
FixedParameters [i].Location);
return false;
}
if (base_name == array_par_name){
Error_DuplicateParameterName (base_name,
FixedParameters [i].Location);
return false;
}
}
return true;
}
///
/// Returns the signature of the Parameters evaluated in
/// the @ec EmitContext
///
public string GetSignature (EmitContext ec)
{
if (signature == null){
VerifyArgs ();
ComputeSignature (ec);
}
return signature;
}
///
/// Returns the paramenter information based on the name
///
public Parameter GetParameterByName (string name, out int idx)
{
idx = 0;
int i = 0;
if (FixedParameters != null){
foreach (Parameter par in FixedParameters){
if (par.Name == name){
idx = i;
return par;
}
i++;
}
}
if (ArrayParameter != null){
if (name == ArrayParameter.Name){
idx = i;
return ArrayParameter;
}
}
return null;
}
public Parameter GetParameterByName (string name)
{
int idx;
return GetParameterByName (name, out idx);
}
bool ComputeParameterTypes (EmitContext ec)
{
int extra = (ArrayParameter != null) ? 1 : 0;
int i = 0;
int pc;
if (FixedParameters == null)
pc = extra;
else
pc = extra + FixedParameters.Length;
types = new Type [pc];
if (!VerifyArgs ()){
FixedParameters = null;
return false;
}
bool failed = false;
if (FixedParameters != null){
foreach (Parameter p in FixedParameters){
Type t = null;
if (p.Resolve (ec))
t = p.ExternalType ();
else
failed = true;
types [i] = t;
i++;
}
}
if (extra > 0){
if (ArrayParameter.Resolve (ec))
types [i] = ArrayParameter.ExternalType ();
else
failed = true;
}
if (failed){
types = null;
return false;
}
return true;
}
///
/// Returns the argument types as an array
///
static Type [] no_types = new Type [0];
public Type [] GetParameterInfo (EmitContext ec)
{
if (types != null)
return types;
if (FixedParameters == null && ArrayParameter == null)
return no_types;
if (ComputeParameterTypes (ec) == false){
types = null;
return null;
}
return types;
}
///
/// Returns the type of a given parameter, and stores in the `is_out'
/// boolean whether this is an out or ref parameter.
///
/// Note that the returned type will not contain any dereference in this
/// case (ie, you get "int" for a ref int instead of "int&"
///
public Type GetParameterInfo (EmitContext ec, int idx, out Parameter.Modifier mod)
{
mod = Parameter.Modifier.NONE;
if (!VerifyArgs ()){
FixedParameters = null;
return null;
}
if (FixedParameters == null && ArrayParameter == null)
return null;
if (types == null)
if (ComputeParameterTypes (ec) == false)
return null;
//
// If this is a request for the variable lenght arg.
//
int array_idx = (FixedParameters != null ? FixedParameters.Length : 0);
if (idx == array_idx)
return types [idx];
//
// Otherwise, it is a fixed parameter
//
Parameter p = FixedParameters [idx];
mod = p.ModFlags;
if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
mod |= Parameter.Modifier.ISBYREF;
return p.ParameterType;
}
public CallingConventions GetCallingConvention ()
{
if (HasArglist)
return CallingConventions.VarArgs;
else
return CallingConventions.Standard;
}
//
// The method's attributes are passed in because we need to extract
// the "return:" attribute from there to apply on the return type
//
public void LabelParameters (EmitContext ec, MethodBase builder)
{
//
// Define each type attribute (in/out/ref) and
// the argument names.
//
int i = 0;
MethodBuilder mb = builder as MethodBuilder;
ConstructorBuilder cb = builder as ConstructorBuilder;
if (FixedParameters != null) {
for (i = 0; i < FixedParameters.Length; i++) {
FixedParameters [i].DefineParameter (ec, mb, cb, i + 1);
}
}
if (ArrayParameter != null){
ParameterBuilder pb;
Parameter array_param = ArrayParameter;
if (mb == null)
pb = cb.DefineParameter (
i + 1, array_param.Attributes,
array_param.Name);
else
pb = mb.DefineParameter (
i + 1, array_param.Attributes,
array_param.Name);
CustomAttributeBuilder a = new CustomAttributeBuilder (
TypeManager.cons_param_array_attribute, new object [0]);
pb.SetCustomAttribute (a);
}
}
public string GetSignatureForError ()
{
StringBuilder sb = new StringBuilder ("(");
if (FixedParameters != null) {
for (int i = 0; i < FixedParameters.Length; ++i) {
sb.Append (FixedParameters[i].GetSignatureForError ());
if (i < FixedParameters.Length - 1)
sb.Append (", ");
}
}
if (ArrayParameter != null) {
if (sb.Length > 0)
sb.Append (", ");
sb.Append (ArrayParameter.GetSignatureForError ());
}
if (HasArglist) {
if (sb.Length > 0)
sb.Append (", ");
sb.Append ("__arglist");
}
sb.Append (')');
return sb.ToString ();
}
}
}