Upgrade C# Protobuf projects to .NET 8.0.

This change updates the target frameworks for various C# projects within Protobuf to .NET 8.0, while also maintaining netstandard2.0 for the core library. Support for older frameworks like net45, net50, and netstandard1.1 has been removed.

This updates our project to match our support policy in https://github.com/google/oss-policies-info/blob/main/foundational-dotnet-support-matrix.md which actually dropped support for net45, net50, etc long ago.

PiperOrigin-RevId: 919111969

.github/workflows/test_csharp.yml

@@ -27,7 +27,7 @@ jobs:
       - name: Run tests
         uses: protocolbuffers/protobuf-ci/docker@v5
         with:
-          image: us-docker.pkg.dev/protobuf-build/containers/test/linux/csharp:9.0.0-3.1.415-6.0.100-9fc33a0c378b5affd3c85d3f5ae4f330993048f7
+          image: us-docker.pkg.dev/protobuf-build/containers/test/linux/csharp:9.0.0-3.1.415-8.0.100-05b57cb3d33f45f689c1dace146b6b9619d78872
           credentials: ${{ secrets.GAR_SERVICE_ACCOUNT }}
           entrypoint: /bin/bash
           command: >-
@@ -35,7 +35,7 @@ jobs:
             cd csharp &&
             dotnet restore src/Google.Protobuf.sln &&
             dotnet build -c Release src/Google.Protobuf.sln &&
-            dotnet test -c Release -f net6.0 src/Google.Protobuf.Test/Google.Protobuf.Test.csproj"
+            dotnet test -c Release -f net8.0 src/Google.Protobuf.Test/Google.Protobuf.Test.csproj"
 
       - name: Clear bazel between docker instances
         run: sudo rm -rf _build .repository-cache
@@ -43,10 +43,10 @@ jobs:
       - name: Run conformance tests
         uses: protocolbuffers/protobuf-ci/bazel-docker@v5
         with:
-          image: us-docker.pkg.dev/protobuf-build/containers/test/linux/csharp:9.0.0-3.1.415-6.0.100-9fc33a0c378b5affd3c85d3f5ae4f330993048f7
+          image: us-docker.pkg.dev/protobuf-build/containers/test/linux/csharp:9.0.0-3.1.415-8.0.100-05b57cb3d33f45f689c1dace146b6b9619d78872
           credentials: ${{ secrets.GAR_SERVICE_ACCOUNT }}
           bazel-cache: csharp_linux
-          bazel: test //csharp:conformance_test --action_env=DOTNET_CLI_TELEMETRY_OPTOUT=1 --test_env=DOTNET_CLI_HOME=/home/bazel
+          bazel: test //csharp:conformance_test --action_env=PATH --action_env=DOTNET_CLI_TELEMETRY_OPTOUT=1 --test_env=DOTNET_CLI_HOME=/home/bazel
 
   windows:
     name: Windows
@@ -60,7 +60,7 @@ jobs:
       - name: Setup dotnet
         uses: actions/setup-dotnet@baa11fbfe1d6520db94683bd5c7a3818018e4309  # v5.1.0
         with:
-          dotnet-version: '6.0.x'
+          dotnet-version: '8.0.x'
 
       - name: Run tests
         uses: protocolbuffers/protobuf-ci/bash@v5
@@ -85,13 +85,13 @@ jobs:
         # (we want to avoid references to ~/.nuget that won't be available in the subsequent docker run)
         uses: protocolbuffers/protobuf-ci/docker@v5
         with:
-          image: mcr.microsoft.com/dotnet/sdk:6.0.100-bullseye-slim
+          image: mcr.microsoft.com/dotnet/sdk:8.0.100-bookworm-slim
           credentials: ${{ secrets.GAR_SERVICE_ACCOUNT }}
           command: >-
             /bin/bash -cex '
             DOTNET_CLI_TELEMETRY_OPTOUT=true
             DOTNET_SKIP_FIRST_TIME_EXPERIENCE=true
-            dotnet publish -c Release -f net6.0 /workspace/csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj'
+            dotnet publish -c Release -f net8.0 /workspace/csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj'
 
       - name: Use an actual aarch64 docker image to run protobuf C# tests with an emulator
         # "dotnet vstest" allows running tests from a pre-built project.
@@ -102,11 +102,11 @@ jobs:
         #   we just run map the user's home to a throwaway temporary directory
         uses: protocolbuffers/protobuf-ci/docker@v5
         with:
-          image: mcr.microsoft.com/dotnet/sdk:6.0.100-bullseye-slim-arm64v8
+          image: mcr.microsoft.com/dotnet/sdk:8.0.100-bookworm-slim-arm64v8
           skip-staleness-check: true
           credentials: ${{ secrets.GAR_SERVICE_ACCOUNT }}
           command: >-
             /bin/bash -cex '
             DOTNET_CLI_TELEMETRY_OPTOUT=true
             DOTNET_SKIP_FIRST_TIME_EXPERIENCE=true
-            dotnet vstest /workspace/csharp/src/Google.Protobuf.Test/bin/Release/net6.0/publish/Google.Protobuf.Test.dll'
+            dotnet vstest /workspace/csharp/src/Google.Protobuf.Test/bin/Release/net8.0/publish/Google.Protobuf.Test.dll'

appveyor.bat

@@ -38,7 +38,7 @@ dotnet restore
 dotnet build -c %configuration% || goto error
 
 echo Testing C#
-dotnet test -c %configuration% -f net6.0 Google.Protobuf.Test\Google.Protobuf.Test.csproj || goto error
+dotnet test -c %configuration% -f net8.0 Google.Protobuf.Test\Google.Protobuf.Test.csproj || goto error
 dotnet test -c %configuration% -f net462 Google.Protobuf.Test\Google.Protobuf.Test.csproj || goto error
 
 goto :EOF

csharp/BUILD.bazel

@@ -103,7 +103,7 @@ inline_sh_test(
         pushd `dirname $(location src/Google.Protobuf.sln)`/..
         dotnet restore src/Google.Protobuf.sln
         dotnet build -c Release src/Google.Protobuf.sln
-        dotnet test -c Release -f net6.0 src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
+        dotnet test -c Release -f net8.0 src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
         popd
     """,
 )

csharp/buildall.sh

@@ -10,8 +10,8 @@ dotnet restore $SRC/Google.Protobuf.sln
 dotnet build -c $CONFIG $SRC/Google.Protobuf.sln
 
 echo Running tests.
-# Only test net6.0, which uses the .NET runtime.
+# Only test net8.0, which uses the .NET runtime.
 # If we want to test the .NET 4.5 version separately, we could
 # run Mono explicitly. However, we don't have any differences between
 # the .NET 4.5 and netstandard2.1 assemblies.
-dotnet test -c $CONFIG -f net6.0 $SRC/Google.Protobuf.Test/Google.Protobuf.Test.csproj
+dotnet test -c $CONFIG -f net8.0 $SRC/Google.Protobuf.Test/Google.Protobuf.Test.csproj

csharp/compatibility_tests/v3.0.0/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj

@@ -1,8 +1,8 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>net462;net6.0</TargetFrameworks>
+    <TargetFrameworks>net462;net8.0</TargetFrameworks>
     <AssemblyOriginatorKeyFile>../../keys/Google.Protobuf.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
     <IsPackable>False</IsPackable>

csharp/compatibility_tests/v3.0.0/test.sh

@@ -22,7 +22,7 @@ function run_test() {
   dotnet restore src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
   dotnet build -c Release src/Google.Protobuf/Google.Protobuf.csproj
   dotnet build -c Release src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
-  dotnet run -c Release -f net6.0 -p src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
+  dotnet run -c Release -f net8.0 -p src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
 }
 
 set -ex

csharp/src/AddressBook/AddressBook.csproj

@@ -1,7 +1,7 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <OutputType>Exe</OutputType>
     <StartupObject>Google.Protobuf.Examples.AddressBook.Program</StartupObject>
     <IsPackable>False</IsPackable>

csharp/src/Google.Protobuf.Conformance/BUILD.bazel

@@ -58,7 +58,7 @@ genrule(
         SRCDIR=$$(dirname $(location :Program.cs))
         cp $(location //conformance:conformance_csharp_proto) $$SRCDIR
         DOTNET_CLI_HOME=/tmp ./$(location :build_conformance_test)
-        cp -r $$SRCDIR/bin/Release/net6.0/* $(RULEDIR)
+        cp -r $$SRCDIR/bin/Release/net8.0/* $(RULEDIR)
     """,
     tools = [":build_conformance_test"],
     visibility = ["//visibility:private"],

csharp/src/Google.Protobuf.Conformance/Google.Protobuf.Conformance.csproj

@@ -1,7 +1,7 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <OutputType>Exe</OutputType>
     <IsPackable>False</IsPackable>
   </PropertyGroup>

csharp/src/Google.Protobuf.JsonDump/Google.Protobuf.JsonDump.csproj

@@ -1,7 +1,7 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <OutputType>Exe</OutputType>
     <IsPackable>False</IsPackable>
   </PropertyGroup>

csharp/src/Google.Protobuf.Test.TestProtos/Google.Protobuf.Test.TestProtos.csproj

@@ -6,7 +6,7 @@
     and without the internal visibility from the test project (all of which have caused issues in the past).
   -->
   <PropertyGroup>
-    <TargetFrameworks>net462;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>net462;net8.0;netstandard2.0</TargetFrameworks>
     <LangVersion>10.0</LangVersion>
     <AssemblyOriginatorKeyFile>../../keys/Google.Protobuf.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>

csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net462;net6.0</TargetFrameworks>
+    <TargetFrameworks>net462;net8.0</TargetFrameworks>
     <AssemblyOriginatorKeyFile>../../keys/Google.Protobuf.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
     <IsPackable>False</IsPackable>

csharp/src/Google.Protobuf.Test/RefStructCompatibilityTest.cs

@@ -37,7 +37,7 @@ namespace Google.Protobuf
 
             var currentAssemblyDir = Path.GetDirectoryName(typeof(RefStructCompatibilityTest).GetTypeInfo().Assembly.Location);
             var testProtosProjectDir = Path.GetFullPath(Path.Combine(currentAssemblyDir, "..", "..", "..", "..", "Google.Protobuf.Test.TestProtos"));
-            var testProtosOutputDir = (currentAssemblyDir.Contains("bin/Debug/") || currentAssemblyDir.Contains("bin\\Debug\\")) ? "bin\\Debug\\net462" : "bin\\Release\\net462";
+            var testProtosOutputDir = (currentAssemblyDir.Contains("bin/Debug/") || currentAssemblyDir.Contains("bin\\Debug\\")) ? "bin\\Debug\\netstandard2.0" : "bin\\Release\\netstandard2.0";
 
             // If "ref struct" types are used in the generated code, compilation with an old compiler will fail with the following error:
             // "XYZ is obsolete: 'Types with embedded references are not supported in this version of your compiler.'"
@@ -47,7 +47,7 @@ namespace Google.Protobuf
             // We suppress CS1691, which flags a warning for the generated line of
             // #pragma warning disable 1591, 0612, 3021, 8981
             // because CS8981 is unknown to this version of the compiler.
-            var args = $"-langversion:3 -nologo -nowarn:1691 -target:library {compatibilityFlag} -reference:{testProtosOutputDir}\\Google.Protobuf.dll -out:{testProtosOutputDir}\\TestProtos.RefStructCompatibilityTest.OldCompiler.dll {sources}";
+            var args = $"-langversion:3 -nologo -nowarn:1691 -target:library {compatibilityFlag} -reference:netstandard.dll -reference:{testProtosOutputDir}\\Google.Protobuf.dll -out:{testProtosOutputDir}\\TestProtos.RefStructCompatibilityTest.OldCompiler.dll {sources}";
             RunOldCsharpCompilerAndCheckSuccess(args, testProtosProjectDir);
         }
 

csharp/src/Google.Protobuf/Collections/RepeatedField.cs

@@ -712,11 +712,7 @@ namespace Google.Protobuf.Collections
             // 2. validate that size of csharp element T is matching the size of protobuf wire size
             //    NOTE: cannot use bool with this span because csharp marshal it as 4 bytes
             if (BitConverter.IsLittleEndian && (codec.FixedSize > 0 &&
-#if GOOGLE_PROTOBUF_SUPPORT_GENERIC_SIZEOF
             Marshal.SizeOf<T>()
-#else
-            Marshal.SizeOf(typeof(T))
-#endif
              == codec.FixedSize))
             {
                 handle = GCHandle.Alloc(array, GCHandleType.Pinned);

csharp/src/Google.Protobuf/Google.Protobuf.csproj

@@ -8,12 +8,12 @@
     <VersionPrefix>3.36.0</VersionPrefix>
     <LangVersion>10.0</LangVersion>
     <Authors>Google Inc.</Authors>
-    <TargetFrameworks>netstandard1.1;netstandard2.0;net45;net50</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net8.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyOriginatorKeyFile>../../keys/Google.Protobuf.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
     <PackageTags>Protocol;Buffers;Binary;Serialization;Format;Google;proto;proto3</PackageTags>
-    <PackageReleaseNotes>C# proto3 support</PackageReleaseNotes>
+    <PackageReleaseNotes>C# proto support</PackageReleaseNotes>
     <PackageProjectUrl>https://github.com/protocolbuffers/protobuf</PackageProjectUrl>
     <PackageLicenseExpression>BSD-3-Clause</PackageLicenseExpression>
     <RepositoryType>git</RepositoryType>
@@ -28,12 +28,9 @@
     <NoWarn>$(NoWarn);NETSDK1195;NETSDK1210</NoWarn>
   </PropertyGroup>
 
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
-    <DefineConstants>$(DefineConstants);GOOGLE_PROTOBUF_SUPPORT_FAST_STRING;GOOGLE_PROTOBUF_SUPPORT_GENERIC_SIZEOF</DefineConstants>
-  </PropertyGroup>
 
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'net50' ">
-    <DefineConstants>$(DefineConstants);GOOGLE_PROTOBUF_SUPPORT_FAST_STRING;GOOGLE_PROTOBUF_SUPPORT_GENERIC_SIZEOF;GOOGLE_PROTOBUF_SIMD</DefineConstants>
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net8.0' ">
+    <DefineConstants>$(DefineConstants);GOOGLE_PROTOBUF_SIMD</DefineConstants>
   </PropertyGroup>
 
   <ItemGroup>
@@ -42,14 +39,8 @@
     <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0"/>
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'net45' OR '$(TargetFramework)' == 'netstandard1.1' ">
-    <!-- TODO -->
-    <PackageReference Include="System.Memory" Version="4.5.3"/>
-  </ItemGroup>
-
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
     <PackageReference Include="System.Memory" Version="4.5.3"/>
-    <!-- Needed for netcoreapp3.1 to work correctly. .NET is not able to load the assembly without this -->
     <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.5.2"/>
   </ItemGroup>
 

csharp/src/Google.Protobuf/ParsingPrimitives.cs

@@ -570,7 +570,6 @@ namespace Google.Protobuf
                 throw InvalidProtocolBufferException.NegativeSize();
             }
 
-#if GOOGLE_PROTOBUF_SUPPORT_FAST_STRING
             if (length <= state.bufferSize - state.bufferPos)
             {
                 // Fast path: all bytes to decode appear in the same span.
@@ -595,7 +594,6 @@ namespace Google.Protobuf
                 state.bufferPos += length;
                 return value;
             }
-#endif
 
             return ReadStringSlow(ref buffer, ref state, length);
         }
@@ -607,7 +605,6 @@ namespace Google.Protobuf
         {
             ValidateCurrentLimit(ref buffer, ref state, length);
 
-#if GOOGLE_PROTOBUF_SUPPORT_FAST_STRING
             if (IsDataAvailable(ref state, length))
             {
                 // Read string data into a temporary buffer, either stackalloc'ed or from ArrayPool
@@ -649,7 +646,6 @@ namespace Google.Protobuf
                     }
                 }
             }
-#endif
 
             // Slow path: Build a byte array first then copy it.
             // This will be called when reading from a Stream because we don't know the length of the stream,

global.json

@@ -1,6 +1,6 @@
-{
+{
   "sdk": {
-    "version": "6.0.100",
+    "version": "8.0.100",
     "rollForward": "latestMinor"
   }
 }