Provide repro for missing backing field

See dotnet/roslyn#74634 and dotnet/orleans#9092

Analyzer/Analyzer.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <LangVersion>Latest</LangVersion>
+    <IsRoslynComponent>true</IsRoslynComponent>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.5.0" />
+  </ItemGroup>
+
+</Project>

Analyzer/Extensions.cs

@@ -0,0 +1,34 @@
+using Microsoft.CodeAnalysis;
+
+internal static class Extensions
+{
+    public static IEnumerable<INamedTypeSymbol> GetAllTypes(this Compilation compilation, bool includeReferenced = true)
+        => compilation.Assembly
+            .GetAllTypes()
+            .OfType<INamedTypeSymbol>()
+            .Concat(compilation.GetUsedAssemblyReferences()
+            .SelectMany(r =>
+            {
+                if (compilation.GetAssemblyOrModuleSymbol(r) is IAssemblySymbol asm)
+                    return asm.GetAllTypes().OfType<INamedTypeSymbol>();
+
+                return Array.Empty<INamedTypeSymbol>();
+            }));
+
+    public static IEnumerable<INamedTypeSymbol> GetAllTypes(this IAssemblySymbol assembly)
+        => GetAllTypes(assembly.GlobalNamespace);
+
+    static IEnumerable<INamedTypeSymbol> GetAllTypes(INamespaceSymbol namespaceSymbol)
+    {
+        foreach (var typeSymbol in namespaceSymbol.GetTypeMembers())
+            yield return typeSymbol;
+
+        foreach (var childNamespace in namespaceSymbol.GetNamespaceMembers())
+        {
+            foreach (var typeSymbol in GetAllTypes(childNamespace))
+            {
+                yield return typeSymbol;
+            }
+        }
+    }
+}

Analyzer/Generator.cs

@@ -0,0 +1,52 @@
+using System.Text;
+using Microsoft.CodeAnalysis;
+
+[Generator]
+public class Generator : IIncrementalGenerator
+{
+    public void Initialize(IncrementalGeneratorInitializationContext context)
+    {
+        context.RegisterSourceOutput(context.CompilationProvider, (ctx, compilation) =>
+        {
+            var builder = new StringBuilder();
+            var local = compilation.GetAllTypes().Single(x => x.Name == "Local");
+            var localMembers = local.GetMembers().Select(x => x.Name).OrderBy(x => x).ToList();
+
+            var referenced = compilation.GetUsedAssemblyReferences()
+                .Select(x => compilation.GetAssemblyOrModuleSymbol(x))
+                .Where(x => x is IAssemblySymbol)
+                .Select(x => (IAssemblySymbol)x)
+                .SelectMany(x => x.GetAllTypes())
+                .Single(x => x.Name == "External");
+
+            var referencedMembers = referenced.GetMembers().Select(x => x.Name).OrderBy(x => x).ToList();
+            var left = 0;
+            var right = 0;
+
+            builder.Append("// ").Append(local.Name).Append(new string(' ', 40 - local.Name.Length)).AppendLine(referenced.Name);
+            builder.Append("// ").AppendLine(new string('-', 80));
+
+            while (left < localMembers.Count)
+            {
+                var x = localMembers[left];
+                var y = referencedMembers[right];
+                // print both members if they match
+                // print only the local member if it's not in the referenced type
+                // increment variables accordingly
+                if (x == y)
+                {
+                    builder.Append("// ").Append(x).Append(new string(' ', 40 - x.Length)).AppendLine(y);
+                    left++;
+                    right++;
+                }
+                else
+                {
+                    builder.Append("// ").Append(x).Append(new string(' ', 40 - x.Length)).AppendLine();
+                    left++;
+                }
+            }
+
+            ctx.AddSource("RecordMembers.cs", builder.ToString());
+        });
+    }
+}

Analyzer/Properties/launchSettings.json

@@ -0,0 +1,8 @@
+{
+  "profiles": {
+    "Roslyn": {
+      "commandName": "DebugRoslynComponent",
+      "targetProject": "..\\Library\\Library.csproj"
+    }
+  }
+}

Library/Library.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Analyzer\Analyzer.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+    <ProjectReference Include="..\ReferencedLibrary\ReferencedLibrary.csproj" />
+  </ItemGroup>
+
+</Project>

Library/Record.cs

@@ -0,0 +1,12 @@
+// #error version
+
+public record Local(int Amount);
+
+public static class Program
+{
+    public static void Main()
+    {
+        // Fake consuming the referenced type, to bring it into the GetUsedAssemblyReferences
+        Console.WriteLine(new External(42).Amount);
+    }
+}

RecordBackingField.sln

@@ -0,0 +1,37 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.11.35005.142
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ReferencedLibrary", "ReferencedLibrary\ReferencedLibrary.csproj", "{233DC959-D567-4DE8-8FA3-224B92CDCA31}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Library", "Library\Library.csproj", "{F75D1708-8126-4104-8A14-8C5322719217}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Analyzer", "Analyzer\Analyzer.csproj", "{6D44E0BF-AE44-43B9-84A6-D60EFF3D9C1A}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{233DC959-D567-4DE8-8FA3-224B92CDCA31}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{233DC959-D567-4DE8-8FA3-224B92CDCA31}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{233DC959-D567-4DE8-8FA3-224B92CDCA31}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{233DC959-D567-4DE8-8FA3-224B92CDCA31}.Release|Any CPU.Build.0 = Release|Any CPU
+		{F75D1708-8126-4104-8A14-8C5322719217}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{F75D1708-8126-4104-8A14-8C5322719217}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{F75D1708-8126-4104-8A14-8C5322719217}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{F75D1708-8126-4104-8A14-8C5322719217}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6D44E0BF-AE44-43B9-84A6-D60EFF3D9C1A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6D44E0BF-AE44-43B9-84A6-D60EFF3D9C1A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6D44E0BF-AE44-43B9-84A6-D60EFF3D9C1A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6D44E0BF-AE44-43B9-84A6-D60EFF3D9C1A}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {CF912B90-ABB5-4AC7-AB17-6DF2F8262EDB}
+	EndGlobalSection
+EndGlobal

ReferencedLibrary/Record.cs

@@ -0,0 +1 @@
+public record External(int Amount);

ReferencedLibrary/ReferencedLibrary.csproj

@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

readme.md

@@ -0,0 +1,42 @@
+# Repro for missing backing field in referenced project record with primary constructor
+
+See [reported issue](https://github.com/dotnet/roslyn/issues/74634).
+
+## Steps to reproduce
+
+Run the project setting a breakpoint in the generator.
+Alternatively, just compile the solution and inspect the generated 
+code in `\Library\obj\Debug\net8.0\generated\Analyzer\Generator\RecordMembers.cs`
+which looks like the following and showcases the missing field symbol:
+
+```
+// Local                                   External
+// --------------------------------------------------------------------------------
+// .ctor                                   .ctor
+// .ctor                                   .ctor
+// <Amount>k__BackingField                 
+// <Clone>$                                <Clone>$
+// Amount                                  Amount
+// Deconstruct                             Deconstruct
+// EqualityContract                        EqualityContract
+// Equals                                  Equals
+// Equals                                  Equals
+// get_Amount                              get_Amount
+// get_EqualityContract                    get_EqualityContract
+// GetHashCode                             GetHashCode
+// op_Equality                             op_Equality
+// op_Inequality                           op_Inequality
+// PrintMembers                            PrintMembers
+// set_Amount                              set_Amount
+// ToString                                ToString
+```
+
+Both record definitions are the same except for the name:
+
+```csharp
+// Library
+public record Local(int Amount);
+
+// External
+public record External(int Amount);
+```