// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
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// without restriction, including without limitation the rights to use, copy, modify, merge,
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// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
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// DEALINGS IN THE SOFTWARE.

using System;

namespace ICSharpCode.Decompiler.Tests.TestCases.Correctness
{
	public class UnsafeCode
	{
		struct SimpleStruct
		{
			public int X;
			public double Y;
		}

		static void Main()
		{
			// TODO: test behavior, or convert this into a pretty-test
			// (but for now, it's already valuable knowing whether the decompiled code can be re-compiled)
		}

		public unsafe int* NullPointer
		{
			get {
				return null;
			}
		}

		public unsafe int* PointerCast(long* p)
		{
			return (int*)p;
		}

		public unsafe long ConvertDoubleToLong(double d)
		{
			return *(long*)(&d);
		}

		public unsafe double ConvertLongToDouble(long d)
		{
			return *(double*)(&d);
		}

		public unsafe int ConvertFloatToInt(float d)
		{
			return *(int*)(&d);
		}

		public unsafe float ConvertIntToFloat(int d)
		{
			return *(float*)(&d);
		}

		public unsafe void PassRefParameterAsPointer(ref int p)
		{
			fixed (int* ptr = &p) {
				this.PassPointerAsRefParameter(ptr);
			}
		}

		public unsafe void PassPointerAsRefParameter(int* p)
		{
			this.PassRefParameterAsPointer(ref *p);
		}

		public unsafe void AddressInMultiDimensionalArray(double[,] matrix)
		{
			fixed (double* ptr = &matrix[1, 2]) {
				this.PointerReferenceExpression(ptr);
				this.PointerReferenceExpression(ptr);
			}
		}

		public unsafe int MultipleExitsOutOfFixedBlock(int[] arr)
		{
			fixed (int* ptr = &arr[0]) {
				if (*ptr < 0)
					return *ptr;
				if (*ptr == 21)
					return 42;
				if (*ptr == 42)
					goto outside;
			}
			return 1;
			outside:
			Console.WriteLine("outside");
			return 2;
		}

		public unsafe void FixedStringAccess(string text)
		{
			fixed (char* ptr = text) {
				char* ptr2 = ptr;
				while (*ptr2 != '\0') {
					*ptr2 = 'A';
					ptr2++;
				}
			}
		}

		public unsafe void PutDoubleIntoLongArray1(long[] array, int index, double val)
		{
			fixed (long* ptr = array) {
				((double*)ptr)[index] = val;
			}
		}

		public unsafe void PutDoubleIntoLongArray2(long[] array, int index, double val)
		{
			fixed (long* ptr = &array[index]) {
				*(double*)ptr = val;
			}
		}

		public unsafe string PointerReferenceExpression(double* d)
		{
			return d->ToString();
		}

		public unsafe string PointerReferenceExpression2(long addr)
		{
			return ((int*)addr)->ToString();
		}

		public unsafe void FixMultipleStrings(string text)
		{
			fixed (char* ptr = text, userName = Environment.UserName, ptr2 = text) {
				*ptr = 'c';
				*userName = 'd';
				*ptr2 = 'e';
			}
		}

		public unsafe string StackAlloc(int count)
		{
			char* ptr = stackalloc char[count];
			char* ptr2 = stackalloc char[100];
			for (int i = 0; i < count; i++) {
				ptr[i] = (char)i;
			}
			return this.PointerReferenceExpression((double*)ptr);
		}

		public unsafe string StackAllocStruct(int count)
		{
			SimpleStruct* s = stackalloc SimpleStruct[checked(count * 2)];
			SimpleStruct* p = stackalloc SimpleStruct[10];
			return this.PointerReferenceExpression(&s->Y);
		}

		public unsafe int* PointerArithmetic(int* p)
		{
			return p + 2;
		}

		public unsafe byte* PointerArithmetic2(long* p, int y, int x)
		{
			return (byte*)((short*)p + (y * x));
		}

		public unsafe long* PointerArithmetic3(long* p)
		{
			return (long*)((byte*)p + 3);
		}

		public unsafe long* PointerArithmetic4(void* p)
		{
			return (long*)((byte*)p + 3);
		}

		public unsafe int PointerArithmetic5(void* p, byte* q, int i)
		{
			return (int)(q[i] + *(byte*)p);
		}

		public unsafe int PointerSubtraction(long* p, long* q)
		{
			return (int)((long)(p - q));
		}

		public unsafe int PointerSubtraction2(long* p, short* q)
		{
			return (int)((long)((byte*)p - (byte*)q));
		}

		public unsafe int PointerSubtraction3(void* p, void* q)
		{
			return (int)((long)((byte*)p - (byte*)q));
		}

		unsafe ~UnsafeCode()
		{
			this.PassPointerAsRefParameter(this.NullPointer);
		}
	}
}