[cdac] Make contracts tests use mock/placeholder target instead of ac…

…tual target (#110027)

- Separate helpers for testing an actual contract descriptor from helpers for mock memory
  - Tests/helpers for the contract descriptor are now under the `ContractDescriptor` folder
- Make all contracts tests use the mock target instead of creating a contract descriptor and using the `ContractDescriptorTarget`
- Update root namespaces from `Microsoft.Diagnostics.DataContractReader.UnitTests` -> `Microsoft.Diagnostics.DataContractReader.Tests` to match assembly name

src/native/managed/cdacreader/tests/CodeVersionsTests.cs

@@ -7,7 +7,7 @@
 using Moq;
 using Xunit;
 
-namespace Microsoft.Diagnostics.DataContractReader.UnitTests;
+namespace Microsoft.Diagnostics.DataContractReader.Tests;
 
 using MockCodeVersions = MockDescriptors.CodeVersions;
 

src/native/managed/cdacreader/tests/ContractDescriptor/ContractDescriptorBuilder.cs

@@ -0,0 +1,173 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+
+namespace Microsoft.Diagnostics.DataContractReader.Tests.ContractDescriptor;
+
+internal class ContractDescriptorBuilder : MockMemorySpace.Builder
+{
+    // These addresses are arbitrary and are used to store the contract descriptor components.
+    // They should not overlap with any other heap fragment addresses.
+    private const ulong ContractDescriptorAddr = 0xaaaaaaaa;
+    private const uint JsonDescriptorAddr = 0xdddddddd;
+    private const uint ContractPointerDataAddr = 0xeeeeeeee;
+
+    private bool _created = false;
+
+    private IReadOnlyCollection<string> _contracts;
+    private IDictionary<DataType, Target.TypeInfo> _types;
+    private IReadOnlyCollection<(string Name, ulong? Value, uint? IndirectIndex, string? TypeName)> _globals;
+    private IReadOnlyCollection<ulong> _indirectValues;
+
+    public ContractDescriptorBuilder(TargetTestHelpers targetTestHelpers)
+        : base(targetTestHelpers)
+    { }
+
+    public ContractDescriptorBuilder SetContracts(IReadOnlyCollection<string> contracts)
+    {
+        if (_created)
+            throw new InvalidOperationException("Context already created");
+        _contracts = contracts;
+        return this;
+    }
+
+    public ContractDescriptorBuilder SetTypes(IDictionary<DataType, Target.TypeInfo> types)
+    {
+        if (_created)
+            throw new InvalidOperationException("Context already created");
+        _types = types;
+        return this;
+    }
+
+    public ContractDescriptorBuilder SetGlobals(IReadOnlyCollection<(string Name, ulong Value, string? TypeName)> globals)
+    {
+        if (_created)
+            throw new InvalidOperationException("Context already created");
+        if (_globals != null)
+            throw new InvalidOperationException("Globals already set");
+        _globals = globals.Select(g => (g.Name, (ulong?)g.Value, (uint?)null, g.TypeName)).ToArray();
+        _indirectValues = null;
+        return this;
+    }
+
+    public ContractDescriptorBuilder SetGlobals(IReadOnlyCollection<(string Name, ulong? Value, uint? IndirectIndex, string? TypeName)> globals, IReadOnlyCollection<ulong> indirectValues)
+    {
+        if (_created)
+            throw new InvalidOperationException("Context already created");
+        if (_globals != null)
+            throw new InvalidOperationException("Globals already set");
+        _globals = globals;
+        _indirectValues = indirectValues;
+        return this;
+    }
+
+    private MockMemorySpace.HeapFragment CreateContractDescriptor(int jsonLength, int pointerDataCount)
+    {
+        byte[] descriptor = new byte[ContractDescriptorHelpers.Size(TargetTestHelpers.Arch.Is64Bit)];
+        ContractDescriptorHelpers.Fill(descriptor, TargetTestHelpers.Arch, jsonLength, JsonDescriptorAddr, pointerDataCount, ContractPointerDataAddr);
+        return new MockMemorySpace.HeapFragment
+        {
+            Address = ContractDescriptorAddr,
+            Data = descriptor,
+            Name = "ContractDescriptor"
+        };
+    }
+
+    private string MakeContractsJson()
+    {
+        if (_contracts.Count == 0)
+            return string.Empty;
+        StringBuilder sb = new();
+        foreach (var c in _contracts)
+        {
+            sb.Append($"\"{c}\": 1,");
+        }
+        Debug.Assert(sb.Length > 0);
+        sb.Length--; // remove trailing comma
+        return sb.ToString();
+    }
+
+    private (MockMemorySpace.HeapFragment json, MockMemorySpace.HeapFragment pointerData) CreateDataDescriptor()
+    {
+        string metadataTypesJson = _types is not null ? ContractDescriptorHelpers.MakeTypesJson(_types) : string.Empty;
+        string metadataGlobalsJson = _globals is not null ? ContractDescriptorHelpers.MakeGlobalsJson(_globals) : string.Empty;
+        string interpolatedContracts = _contracts is not null ? MakeContractsJson() : string.Empty;
+        byte[] jsonBytes = Encoding.UTF8.GetBytes($$"""
+        {
+            "version": 0,
+            "baseline": "empty",
+            "contracts": { {{interpolatedContracts}} },
+            "types": { {{metadataTypesJson}} },
+            "globals": { {{metadataGlobalsJson}} }
+        }
+        """);
+        MockMemorySpace.HeapFragment json = new()
+        {
+            Address = JsonDescriptorAddr,
+            Data = jsonBytes,
+            Name = "JsonDescriptor"
+        };
+
+        MockMemorySpace.HeapFragment pointerData;
+        if (_indirectValues != null)
+        {
+            int pointerSize = TargetTestHelpers.PointerSize;
+            byte[] pointerDataBytes = new byte[_indirectValues.Count * pointerSize];
+            int offset = 0;
+            foreach (var value in _indirectValues)
+            {
+                TargetTestHelpers.WritePointer(pointerDataBytes.AsSpan(offset, pointerSize), value);
+                offset += pointerSize;
+            }
+            pointerData = new MockMemorySpace.HeapFragment
+            {
+                Address = ContractPointerDataAddr,
+                Data = pointerDataBytes,
+                Name = "PointerData"
+            };
+        }
+        else
+        {
+            pointerData = new MockMemorySpace.HeapFragment
+            {
+                Address = ContractPointerDataAddr,
+                Data = Array.Empty<byte>(),
+                Name = "PointerData"
+            };
+        }
+        return (json, pointerData);
+    }
+
+    private ulong CreateDescriptorFragments()
+    {
+        if (_created)
+            throw new InvalidOperationException("Context already created");
+
+        (var json, var pointerData) = CreateDataDescriptor();
+        int pointerDataCount = pointerData.Data is null ? 0 : pointerData.Data.Length / TargetTestHelpers.PointerSize;
+        MockMemorySpace.HeapFragment descriptor = CreateContractDescriptor(json.Data.Length, pointerDataCount);
+
+        AddHeapFragment(descriptor);
+        AddHeapFragment(json);
+        if (pointerData.Data.Length > 0)
+            AddHeapFragment(pointerData);
+
+        _created = true;
+        return descriptor.Address;
+    }
+
+    public bool TryCreateTarget([NotNullWhen(true)] out ContractDescriptorTarget? target)
+    {
+        if (_created)
+            throw new InvalidOperationException("Context already created");
+        ulong contractDescriptorAddress = CreateDescriptorFragments();
+        MockMemorySpace.ReadContext context = GetReadContext();
+        return ContractDescriptorTarget.TryCreate(contractDescriptorAddress, context.ReadFromTarget, out target);
+    }
+}

src/native/managed/cdacreader/tests/ContractDescriptor/ContractDescriptorHelpers.cs

@@ -0,0 +1,156 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Buffers.Binary;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+
+namespace Microsoft.Diagnostics.DataContractReader.Tests.ContractDescriptor;
+
+internal unsafe class ContractDescriptorHelpers
+{
+    public static int Size(bool is64Bit) => is64Bit ? sizeof(ContractDescriptor64) : sizeof(ContractDescriptor32);
+
+    public static void Fill(Span<byte> dest, MockTarget.Architecture arch, int jsonDescriptorSize, uint jsonDescriptorAddr, int pointerDataCount, uint pointerDataAddr)
+    {
+        if (arch.Is64Bit)
+        {
+            ContractDescriptor64.Fill(dest, arch.IsLittleEndian, jsonDescriptorSize, jsonDescriptorAddr, pointerDataCount, pointerDataAddr);
+        }
+        else
+        {
+            ContractDescriptor32.Fill(dest, arch.IsLittleEndian, jsonDescriptorSize, jsonDescriptorAddr, pointerDataCount, pointerDataAddr);
+        }
+    }
+
+    private struct ContractDescriptor32
+    {
+        public ulong Magic = BitConverter.ToUInt64("DNCCDAC\0"u8);
+        public uint Flags = 0x2 /*32-bit*/ | 0x1;
+        public uint DescriptorSize;
+        public uint Descriptor;
+        public uint PointerDataCount;
+        public uint Pad0 = 0;
+        public uint PointerData;
+
+        public ContractDescriptor32() { }
+
+        public static void Fill(Span<byte> dest, bool isLittleEndian, int jsonDescriptorSize, uint jsonDescriptorAddr, int pointerDataCount, uint pointerDataAddr)
+        {
+            ContractDescriptor32 descriptor = new()
+            {
+                DescriptorSize = (uint)jsonDescriptorSize,
+                Descriptor = jsonDescriptorAddr,
+                PointerDataCount = (uint)pointerDataCount,
+                PointerData = pointerDataAddr,
+            };
+            if (BitConverter.IsLittleEndian != isLittleEndian)
+                descriptor.ReverseEndianness();
+
+            MemoryMarshal.AsBytes(MemoryMarshal.CreateSpan(ref descriptor, 1)).CopyTo(dest);
+        }
+
+        private void ReverseEndianness()
+        {
+            Magic = BinaryPrimitives.ReverseEndianness(Magic);
+            Flags = BinaryPrimitives.ReverseEndianness(Flags);
+            DescriptorSize = BinaryPrimitives.ReverseEndianness(DescriptorSize);
+            Descriptor = BinaryPrimitives.ReverseEndianness(Descriptor);
+            PointerDataCount = BinaryPrimitives.ReverseEndianness(PointerDataCount);
+            Pad0 = BinaryPrimitives.ReverseEndianness(Pad0);
+            PointerData = BinaryPrimitives.ReverseEndianness(PointerData);
+        }
+    }
+
+    private struct ContractDescriptor64
+    {
+        public ulong Magic = BitConverter.ToUInt64("DNCCDAC\0"u8);
+        public uint Flags = 0x1;
+        public uint DescriptorSize;
+        public ulong Descriptor;
+        public uint PointerDataCount;
+        public uint Pad0 = 0;
+        public ulong PointerData;
+
+        public ContractDescriptor64() { }
+
+        public static void Fill(Span<byte> dest, bool isLittleEndian, int jsonDescriptorSize, uint jsonDescriptorAddr, int pointerDataCount, uint pointerDataAddr)
+        {
+            ContractDescriptor64 descriptor = new()
+            {
+                DescriptorSize = (uint)jsonDescriptorSize,
+                Descriptor = jsonDescriptorAddr,
+                PointerDataCount = (uint)pointerDataCount,
+                PointerData = pointerDataAddr,
+            };
+            if (BitConverter.IsLittleEndian != isLittleEndian)
+                descriptor.ReverseEndianness();
+
+            MemoryMarshal.AsBytes(MemoryMarshal.CreateSpan(ref descriptor, 1)).CopyTo(dest);
+        }
+
+        private void ReverseEndianness()
+        {
+            Magic = BinaryPrimitives.ReverseEndianness(Magic);
+            Flags = BinaryPrimitives.ReverseEndianness(Flags);
+            DescriptorSize = BinaryPrimitives.ReverseEndianness(DescriptorSize);
+            Descriptor = BinaryPrimitives.ReverseEndianness(Descriptor);
+            PointerDataCount = BinaryPrimitives.ReverseEndianness(PointerDataCount);
+            Pad0 = BinaryPrimitives.ReverseEndianness(Pad0);
+            PointerData = BinaryPrimitives.ReverseEndianness(PointerData);
+        }
+    }
+
+    #region JSON formatting
+    private static string GetTypeJson(string name, Target.TypeInfo info)
+    {
+        string ret = string.Empty;
+        List<string> fields = info.Size is null ? [] : [$"\"!\":{info.Size}"];
+        fields.AddRange(info.Fields.Select(f => $"\"{f.Key}\":{(f.Value.TypeName is null ? f.Value.Offset : $"[{f.Value.Offset},\"{f.Value.TypeName}\"]")}"));
+        return $"\"{name}\":{{{string.Join(',', fields)}}}";
+    }
+
+    public static string MakeTypesJson(IDictionary<DataType, Target.TypeInfo> types)
+    {
+        return string.Join(',', types.Select(t => GetTypeJson(t.Key.ToString(), t.Value)));
+    }
+
+    public static string MakeGlobalsJson(IEnumerable<(string Name, ulong Value, string? Type)> globals)
+    {
+        return MakeGlobalsJson(globals.Select(g => (g.Name, (ulong?)g.Value, (uint?)null, g.Type)));
+    }
+
+    public static string MakeGlobalsJson(IEnumerable<(string Name, ulong? Value, uint? IndirectIndex, string? Type)> globals)
+    {
+        return string.Join(',', globals.Select(FormatGlobal));
+
+        static string FormatGlobal((string Name, ulong? Value, uint? IndirectIndex, string? Type) global)
+        {
+            if (global.Value is ulong value)
+            {
+                return $"\"{global.Name}\": {FormatValue(value, global.Type)}";
+            }
+            else if (global.IndirectIndex is uint index)
+            {
+                return $"\"{global.Name}\": {FormatIndirect(index, global.Type)}";
+            }
+            else
+            {
+                throw new InvalidOperationException("Global must have a value or indirect index");
+            }
+
+        }
+        static string FormatValue(ulong value, string? type)
+        {
+            return type is null ? $"{value}" : $"[{value},\"{type}\"]";
+        }
+        static string FormatIndirect(uint value, string? type)
+        {
+            return type is null ? $"[{value}]" : $"[[{value}],\"{type}\"]";
+        }
+    }
+
+    #endregion JSON formatting
+}

src/native/managed/cdacreader/tests/ContractDescriptorParserTests.cs → src/native/managed/cdacreader/tests/ContractDescriptor/ParserTests.cs

@@ -5,9 +5,9 @@
 using System.Text.Json;
 using Xunit;
 
-namespace Microsoft.Diagnostics.DataContractReader.UnitTests;
+namespace Microsoft.Diagnostics.DataContractReader.Tests.ContractDescriptor;
 
-public class ContractDescriptorParserTests
+public class ParserTests
 {
     [Fact]
     public void ParsesEmptyContract()