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using System;
using System.Collections.Generic;
using System.Text;
using System.Linq.Expressions;
using System.Reflection;
using System.Data.Linq;
using System.Data.Linq.Provider;
using System.Data.Linq.Mapping;
namespace System.Data.Linq.SqlClient {
// convert special method calls and member accesses into known sql nodes
internal static class PreBindDotNetConverter {
internal static SqlNode Convert(SqlNode node, SqlFactory sql, MetaModel model) {
return new Visitor(sql, model).Visit(node);
}
internal static bool CanConvert(SqlNode node) {
SqlBinary bo = node as SqlBinary;
if (bo != null && (IsCompareToValue(bo) || IsVbCompareStringEqualsValue(bo))) {
return true;
}
SqlMember sm = node as SqlMember;
if (sm != null && IsSupportedMember(sm)) {
return true;
}
SqlMethodCall mc = node as SqlMethodCall;
if (mc != null && (IsSupportedMethod(mc) || IsSupportedVbHelperMethod(mc))) {
return true;
}
return false;
}
private static bool IsCompareToValue(SqlBinary bo) {
if (IsComparison(bo.NodeType)
&& bo.Left.NodeType == SqlNodeType.MethodCall
&& bo.Right.NodeType == SqlNodeType.Value) {
SqlMethodCall call = (SqlMethodCall)bo.Left;
return IsCompareToMethod(call) || IsCompareMethod(call);
}
return false;
}
private static bool IsCompareToMethod(SqlMethodCall call) {
return !call.Method.IsStatic && call.Method.Name == "CompareTo" && call.Arguments.Count == 1 && call.Method.ReturnType == typeof(int);
}
private static bool IsCompareMethod(SqlMethodCall call) {
return call.Method.IsStatic && call.Method.Name == "Compare" && call.Arguments.Count > 1 && call.Method.ReturnType == typeof(int);
}
private static bool IsComparison(SqlNodeType nodeType) {
switch (nodeType) {
case SqlNodeType.EQ:
case SqlNodeType.NE:
case SqlNodeType.LT:
case SqlNodeType.LE:
case SqlNodeType.GT:
case SqlNodeType.GE:
case SqlNodeType.EQ2V:
case SqlNodeType.NE2V:
return true;
default:
return false;
}
}
private static bool IsVbCompareStringEqualsValue(SqlBinary bo) {
return IsComparison(bo.NodeType)
&& bo.Left.NodeType == SqlNodeType.MethodCall
&& bo.Right.NodeType == SqlNodeType.Value
&& IsVbCompareString((SqlMethodCall)bo.Left);
}
private static bool IsVbCompareString(SqlMethodCall call) {
return call.Method.IsStatic &&
call.Method.DeclaringType.FullName == "Microsoft.VisualBasic.CompilerServices.Operators" &&
call.Method.Name == "CompareString";
}
private static bool IsSupportedVbHelperMethod(SqlMethodCall mc) {
return IsVbIIF(mc);
}
private static bool IsVbIIF(SqlMethodCall mc) {
return mc.Method.IsStatic &&
mc.Method.DeclaringType.FullName == "Microsoft.VisualBasic.Interaction" && mc.Method.Name == "IIf";
}
private static bool IsSupportedMember(SqlMember m) {
return IsNullableHasValue(m) || IsNullableHasValue(m);
}
private static bool IsNullableValue(SqlMember m) {
return TypeSystem.IsNullableType(m.Expression.ClrType) && m.Member.Name == "Value";
}
private static bool IsNullableHasValue(SqlMember m) {
return TypeSystem.IsNullableType(m.Expression.ClrType) && m.Member.Name == "HasValue";
}
private static bool IsSupportedMethod(SqlMethodCall mc) {
if (mc.Method.IsStatic) {
switch (mc.Method.Name) {
case "op_Equality":
case "op_Inequality":
case "op_LessThan":
case "op_LessThanOrEqual":
case "op_GreaterThan":
case "op_GreaterThanOrEqual":
case "op_Multiply":
case "op_Division":
case "op_Subtraction":
case "op_Addition":
case "op_Modulus":
case "op_BitwiseAnd":
case "op_BitwiseOr":
case "op_ExclusiveOr":
case "op_UnaryNegation":
case "op_OnesComplement":
case "op_False":
return true;
case "Equals":
return mc.Arguments.Count == 2;
case "Concat":
return mc.Method.DeclaringType == typeof(string);
}
}
else {
return mc.Method.Name == "Equals" && mc.Arguments.Count == 1 ||
mc.Method.Name == "GetType" && mc.Arguments.Count == 0;
}
return false;
}
private class Visitor : SqlVisitor {
SqlFactory sql;
MetaModel model;
internal Visitor(SqlFactory sql, MetaModel model) {
this.sql = sql;
this.model = model;
}
internal override SqlExpression VisitBinaryOperator(SqlBinary bo) {
if (IsCompareToValue(bo)) {
SqlMethodCall call = (SqlMethodCall)bo.Left;
if (IsCompareToMethod(call)) {
int iValue = System.Convert.ToInt32(this.Eval(bo.Right), Globalization.CultureInfo.InvariantCulture);
bo = this.MakeCompareTo(call.Object, call.Arguments[0], bo.NodeType, iValue) ?? bo;
}
else if (IsCompareMethod(call)) {
int iValue = System.Convert.ToInt32(this.Eval(bo.Right), Globalization.CultureInfo.InvariantCulture);
bo = this.MakeCompareTo(call.Arguments[0], call.Arguments[1], bo.NodeType, iValue) ?? bo;
}
}
else if (IsVbCompareStringEqualsValue(bo)) {
SqlMethodCall call = (SqlMethodCall)bo.Left;
int iValue = System.Convert.ToInt32(this.Eval(bo.Right), Globalization.CultureInfo.InvariantCulture);
//in VB, comparing a string with Nothing means comparing with ""
SqlValue strValue = call.Arguments[1] as SqlValue;
if (strValue != null && strValue.Value == null) {
SqlValue emptyStr = new SqlValue(strValue.ClrType, strValue.SqlType, String.Empty, strValue.IsClientSpecified, strValue.SourceExpression);
bo = this.MakeCompareTo(call.Arguments[0], emptyStr, bo.NodeType, iValue) ?? bo;
}
else {
bo = this.MakeCompareTo(call.Arguments[0], call.Arguments[1], bo.NodeType, iValue) ?? bo;
}
}
return base.VisitBinaryOperator(bo);
}
private SqlBinary MakeCompareTo(SqlExpression left, SqlExpression right, SqlNodeType op, int iValue) {
if (iValue == 0) {
return sql.Binary(op, left, right);
}
else if (op == SqlNodeType.EQ || op == SqlNodeType.EQ2V) {
switch (iValue) {
case -1:
return sql.Binary(SqlNodeType.LT, left, right);
case 1:
return sql.Binary(SqlNodeType.GT, left, right);
}
}
return null;
}
private SqlExpression CreateComparison(SqlExpression a, SqlExpression b, Expression source) {
SqlExpression lower = sql.Binary(SqlNodeType.LT, a, b);
SqlExpression equal = sql.Binary(SqlNodeType.EQ2V, a, b);
return sql.SearchedCase(
new SqlWhen[] {
new SqlWhen(lower, sql.ValueFromObject(-1, false, source)),
new SqlWhen(equal, sql.ValueFromObject(0, false, source)),
},
sql.ValueFromObject(1, false, source), source
);
}
internal override SqlNode VisitMember(SqlMember m) {
m.Expression = this.VisitExpression(m.Expression);
if (IsNullableValue(m)) {
return sql.UnaryValueOf(m.Expression, m.SourceExpression);
}
else if (IsNullableHasValue(m)) {
return sql.Unary(SqlNodeType.IsNotNull, m.Expression, m.SourceExpression);
}
return m;
}
internal override SqlExpression VisitMethodCall(SqlMethodCall mc) {
mc.Object = this.VisitExpression(mc.Object);
for (int i = 0, n = mc.Arguments.Count; i < n; i++) {
mc.Arguments[i] = this.VisitExpression(mc.Arguments[i]);
}
if (mc.Method.IsStatic) {
if (mc.Method.Name == "Equals" && mc.Arguments.Count == 2) {
return sql.Binary(SqlNodeType.EQ2V, mc.Arguments[0], mc.Arguments[1], mc.Method);
}
else if (mc.Method.DeclaringType == typeof(string) && mc.Method.Name == "Concat") {
SqlClientArray arr = mc.Arguments[0] as SqlClientArray;
List<SqlExpression> exprs = null;
if (arr != null) {
exprs = arr.Expressions;
}
else {
exprs = mc.Arguments;
}
if (exprs.Count == 0) {
return sql.ValueFromObject("", false, mc.SourceExpression);
}
else {
SqlExpression sum;
if (exprs[0].SqlType.IsString || exprs[0].SqlType.IsChar) {
sum = exprs[0];
}
else {
sum = sql.ConvertTo(typeof(string), exprs[0]);
}
for (int i = 1; i < exprs.Count; i++) {
if (exprs[i].SqlType.IsString || exprs[i].SqlType.IsChar) {
sum = sql.Concat(sum, exprs[i]);
}
else {
sum = sql.Concat(sum, sql.ConvertTo(typeof(string), exprs[i]));
}
}
return sum;
}
}
else if (IsVbIIF(mc)) {
return TranslateVbIIF(mc);
}
else {
switch (mc.Method.Name) {
case "op_Equality":
return sql.Binary(SqlNodeType.EQ, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_Inequality":
return sql.Binary(SqlNodeType.NE, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_LessThan":
return sql.Binary(SqlNodeType.LT, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_LessThanOrEqual":
return sql.Binary(SqlNodeType.LE, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_GreaterThan":
return sql.Binary(SqlNodeType.GT, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_GreaterThanOrEqual":
return sql.Binary(SqlNodeType.GE, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_Multiply":
return sql.Binary(SqlNodeType.Mul, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_Division":
return sql.Binary(SqlNodeType.Div, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_Subtraction":
return sql.Binary(SqlNodeType.Sub, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_Addition":
return sql.Binary(SqlNodeType.Add, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_Modulus":
return sql.Binary(SqlNodeType.Mod, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_BitwiseAnd":
return sql.Binary(SqlNodeType.BitAnd, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_BitwiseOr":
return sql.Binary(SqlNodeType.BitOr, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_ExclusiveOr":
return sql.Binary(SqlNodeType.BitXor, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
case "op_UnaryNegation":
return sql.Unary(SqlNodeType.Negate, mc.Arguments[0], mc.Method, mc.SourceExpression);
case "op_OnesComplement":
return sql.Unary(SqlNodeType.BitNot, mc.Arguments[0], mc.Method, mc.SourceExpression);
case "op_False":
return sql.Unary(SqlNodeType.Not, mc.Arguments[0], mc.Method, mc.SourceExpression);
}
}
}
else {
if (mc.Method.Name == "Equals" && mc.Arguments.Count == 1) {
return sql.Binary(SqlNodeType.EQ, mc.Object, mc.Arguments[0]);
}
else if (mc.Method.Name == "GetType" && mc.Arguments.Count == 0) {
MetaType mt = TypeSource.GetSourceMetaType(mc.Object, this.model);
if (mt.HasInheritance) {
Type discriminatorType = mt.Discriminator.Type;
SqlDiscriminatorOf discriminatorOf = new SqlDiscriminatorOf(mc.Object, discriminatorType, this.sql.TypeProvider.From(discriminatorType), mc.SourceExpression);
return this.VisitExpression(sql.DiscriminatedType(discriminatorOf, mt));
}
return this.VisitExpression(sql.StaticType(mt, mc.SourceExpression));
}
}
return mc;
}
private SqlExpression TranslateVbIIF(SqlMethodCall mc) {
//Check to see if the types can be implicitly converted from one to another.
if (mc.Arguments[1].ClrType == mc.Arguments[2].ClrType) {
List<SqlWhen> whens = new List<SqlWhen>(1);
whens.Add(new SqlWhen(mc.Arguments[0], mc.Arguments[1]));
SqlExpression @else = mc.Arguments[2];
while (@else.NodeType == SqlNodeType.SearchedCase) {
SqlSearchedCase sc = (SqlSearchedCase)@else;
whens.AddRange(sc.Whens);
@else = sc.Else;
}
return sql.SearchedCase(whens.ToArray(), @else, mc.SourceExpression);
}
else {
throw Error.IifReturnTypesMustBeEqual(mc.Arguments[1].ClrType.Name, mc.Arguments[2].ClrType.Name);
}
}
internal override SqlExpression VisitTreat(SqlUnary t) {
t.Operand = this.VisitExpression(t.Operand);
Type treatType = t.ClrType;
Type originalType = model.GetMetaType(t.Operand.ClrType).InheritanceRoot.Type;
// .NET nullability rules are that typeof(int)==typeof(int?). Let's be consistent with that:
treatType = TypeSystem.GetNonNullableType(treatType);
originalType = TypeSystem.GetNonNullableType(originalType);
if (treatType == originalType) {
return t.Operand;
}
else if (treatType.IsAssignableFrom(originalType)) {
t.Operand.SetClrType(treatType);
return t.Operand;
}
else if (!treatType.IsAssignableFrom(originalType) && !originalType.IsAssignableFrom(treatType)) {
if (!treatType.IsInterface && !originalType.IsInterface) { // You can't tell when there's an interface involved.
// We statically know the TREAT will result in NULL.
return sql.TypedLiteralNull(treatType, t.SourceExpression);
}
}
//return base.VisitTreat(t);
return t;
}
}
}
}
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