agocke · agocke · Feb 21, 2026 · Feb 20, 2026 · Feb 20, 2026 · Feb 20, 2026
diff --git a/MODULE.bazel.lock b/MODULE.bazel.lock
diff --git a/docs/bazel.md b/docs/bazel.md
@@ -560,7 +560,7 @@ Library tests use the `library_test` macro from `src/tests/live_test.bzl`, which
 runs a reflection-based test runner (`LibraryTestRunner.cs`) under `corerun`.
 Each library test needs a `tests/BUILD.bazel` file.
 
-**Summary**: 20 of ~187 libraries have Bazel test BUILD files.
+**Summary**: 28 of ~187 libraries have Bazel test BUILD files.
 
 ### Tiers
 
@@ -588,35 +588,35 @@ Libraries are grouped by implementation complexity:
 | System.Formats.Asn1 | ✅ | ✅ | 46 test files; ref-only dep |
 | System.IO.FileSystem.AccessControl | ✅ | ❌ | Windows-specific tests |
 | System.IO.FileSystem.DriveInfo | ✅ | ✅ | |
-| System.IO.IsolatedStorage | ✅ | ❌ | |
-| System.IO.MemoryMappedFiles | ✅ | ❌ | |
+| System.IO.IsolatedStorage | ✅ | ❌ | Linked src files use SR (generated string resources) |
+| System.IO.MemoryMappedFiles | ✅ | ❌ | Unix tests use LibraryImport partial methods needing source generator |
 | System.Linq | ✅ | ✅ | 71 test files |
 | System.Memory | ✅ | ✅ | 52143 tests (very large) |
 | System.Net.Primitives | ✅ (ref only) | ❌ | Needs impl build; many tests depend on this |
 | System.Numerics.Vectors | ✅ | ✅ | |
 | System.ObjectModel | ✅ | ✅ | |
-| System.Reflection.Emit | ✅ | ❌ | |
+| System.Reflection.Emit | ✅ | ✅ | 2027/2625 pass; 598 need MetadataLoadContext impl at runtime |
 | System.Reflection.Emit.ILGeneration | ✅ | ✅ | |
 | System.Reflection.Emit.Lightweight | ✅ | ✅ | |
-| System.Reflection.Metadata | ✅ | ❌ | |
+| System.Reflection.Metadata | ✅ | ❌ | 22 embedded resource DLLs need resource embedding support |
 | System.Reflection.TypeExtensions | ✅ | ✅ | 1 test skipped (TinyAssembly.dll content file) |
 | System.Resources.Writer | ✅ | ✅ | |
 | System.Runtime.CompilerServices.VisualC | ✅ | ✅ | |
-| System.Runtime.InteropServices | ✅ | ❌ | |
-| System.Runtime.Intrinsics | ✅ | ❌ | |
-| System.Runtime.Loader | ✅ | ❌ | |
+| System.Runtime.InteropServices | ✅ | ✅ | UnitTests; 2504/2505 pass; Windows/Drawing tests excluded |
+| System.Runtime.Intrinsics | ✅ | ✅ | 12704 tests; Wasm PackedSimd tests excluded |
+| System.Runtime.Loader | ✅ | ❌ | 34 ProjectReferences to sub-projects need separate builds |
 | System.Runtime.Numerics | ✅ | ✅ | 176 tests pass (large) |
-| System.Runtime.Serialization.Formatters | ✅ | ❌ | |
+| System.Runtime.Serialization.Formatters | ✅ | ❌ | Needs ~10 external library builds (CodeDom, Composition, etc.) |
 | System.Security.AccessControl | ✅ | ❌ | Windows-specific tests |
 | System.Security.Claims | ✅ | ✅ | |
 | System.Security.Cryptography | ✅ | ❌ | |
 | System.Security.Principal.Windows | ✅ | ❌ | Windows-specific tests |
 | System.Text.Encoding.Extensions | ✅ | ✅ | |
-| System.Threading | ✅ | ❌ | |
-| System.Threading.Overlapped | ✅ | ❌ | |
-| System.Threading.Tasks.Parallel | ✅ | ❌ | |
-| System.Threading.Thread | ✅ | ❌ | |
-| System.Threading.ThreadPool | ✅ | ❌ | |
+| System.Threading | ✅ | ✅ | 591 tests pass |
+| System.Threading.Overlapped | ✅ | ✅ | 21 tests; 2 skipped |
+| System.Threading.Tasks.Parallel | ✅ | ✅ | 262 tests pass |
+| System.Threading.Thread | ✅ | ✅ | 45/53 pass; 8 need ApartmentState sub-project binaries |
+| System.Threading.ThreadPool | ✅ | ✅ | 69 tests; 1 skipped |
 
 ### Tier 2 — Self-contained, need source BUILD first
 

diff --git a/src/libraries/System.Net.Sockets/BUILD.bazel b/src/libraries/System.Net.Sockets/BUILD.bazel
@@ -0,0 +1,12 @@
+load("//src/libraries:defs.bzl", "netcoreapp_ref_assembly")
+
+netcoreapp_ref_assembly(
+    name = "ref_System.Net.Sockets",
+    srcs = [
+        "ref/System.Net.Sockets.cs",
+    ],
+    deps = [
+        "//src/libraries:ref_System.Runtime",
+        "//src/libraries/System.Net.Primitives:ref_System.Net.Primitives",
+    ],
+)
diff --git a/src/libraries/System.Reflection.Emit/tests/BUILD.bazel b/src/libraries/System.Reflection.Emit/tests/BUILD.bazel
@@ -0,0 +1,36 @@
+load("//src/tests:live_test.bzl", "library_test")
+
+library_test(
+    name = "System.Reflection.Emit.Tests",
+    srcs = glob(
+        ["**/*.cs"],
+        exclude = [
+            # Missing closing brace - upstream bug
+            "TypeBuilder/TypeBuilderInstantiationErrorMessageTests.cs",
+        ],
+    ) + [
+        "//src/libraries/Common/tests:System/IO/TempFile.cs",
+    ],
+    deps = [
+        "//src/libraries/System.Reflection.Emit:ref_System.Reflection.Emit",
+        "//src/libraries/System.Reflection.Emit.ILGeneration:ref_System.Reflection.Emit.ILGeneration",
+        "//src/libraries/System.Reflection.Emit.Lightweight:ref_System.Reflection.Emit.Lightweight",
+        "//src/libraries/System.Reflection.MetadataLoadContext:live_System.Reflection.MetadataLoadContext",
+        "//src/libraries/System.Reflection.Metadata:ref_System.Reflection.Metadata",
+        "//src/libraries/System.Reflection.Primitives:ref_System.Reflection.Primitives",
+        "//src/libraries/System.Collections.Immutable:ref_System.Collections.Immutable",
+        "//src/libraries/System.Collections.Concurrent:ref_System.Collections.Concurrent",
+        "//src/libraries/System.Diagnostics.StackTrace:ref_System.Diagnostics.StackTrace",
+        "//src/libraries/System.Resources.Writer:ref_System.Resources.Writer",
+        "//src/libraries/System.Threading:ref_System.Threading",
+        "//src/libraries/Common/tests:TestUtilities",
+        "@paket.main//microsoft.dotnet.remoteexecutor",
+        "@paket.main//microsoft.dotnet.xunitassert",
+        "@paket.main//microsoft.dotnet.xunitextensions",
+        "@paket.main//xunit.abstractions",
+        "@paket.main//xunit.extensibility.core",
+    ],
+    allow_unsafe_blocks = True,
+    size = "large",
+    keyfile = "@nuget.microsoft.dotnet.arcade.sdk.v10.0.0-beta.26102.102//:tools/snk/Open.snk",
+)
diff --git a/src/libraries/System.Reflection.MetadataLoadContext/BUILD.bazel b/src/libraries/System.Reflection.MetadataLoadContext/BUILD.bazel
@@ -0,0 +1,43 @@
+load("//src/libraries:defs.bzl", "netcoreapp_impl_assembly", "netcoreapp_ref_assembly", "ref_impl_pair")
+
+netcoreapp_ref_assembly(
+    name = "ref_System.Reflection.MetadataLoadContext",
+    srcs = [
+        "ref/System.Reflection.MetadataLoadContext.cs",
+    ],
+    deps = [
+        "//src/libraries:ref_System.Runtime",
+    ],
+)
+
+netcoreapp_impl_assembly(
+    name = "impl_System.Reflection.MetadataLoadContext",
+    srcs = glob(
+        ["src/**/*.cs"],
+        exclude = [
+            # netstandard-only; TypeExtensions.net.cs is used for netcoreapp
+            "src/System/Reflection/TypeLoading/General/TypeExtensions.netstandard.cs",
+        ],
+    ) + [
+        "//src/libraries/Common:src/System/Obsoletions.cs",
+    ],
+    resx_file = "src/Resources/Strings.resx",
+    allow_unsafe_blocks = True,
+    deps = [
+        "//src/libraries:ref_System.Runtime",
+        "//src/libraries/System.Collections:ref_System.Collections",
+        "//src/libraries/System.Collections.Concurrent:ref_System.Collections.Concurrent",
+        "//src/libraries/System.Collections.Immutable:ref_System.Collections.Immutable",
+        "//src/libraries/System.Memory:ref_System.Memory",
+        "//src/libraries/System.Reflection.Metadata:ref_System.Reflection.Metadata",
+        "//src/libraries/System.Runtime.InteropServices:ref_System.Runtime.InteropServices",
+        "//src/libraries/System.Threading:ref_System.Threading",
+    ],
+)
+
+ref_impl_pair(
+    name = "live_System.Reflection.MetadataLoadContext",
+    ref = ":ref_System.Reflection.MetadataLoadContext",
+    lib = ":impl_System.Reflection.MetadataLoadContext",
+    visibility = ["//visibility:public"],
+)
diff --git a/src/libraries/System.Runtime.InteropServices/BUILD.bazel b/src/libraries/System.Runtime.InteropServices/BUILD.bazel
@@ -92,6 +92,54 @@ csharp_library(
     visibility = ["//visibility:public"],
 )
 
+csharp_library(
+    name = "ComInterfaceGenerator",
+    out = "Microsoft.Interop.ComInterfaceGenerator",
+    srcs = glob(["gen/ComInterfaceGenerator/**/*.cs"]) + [
+        "//src/libraries/System.Private.CoreLib:src/System/Diagnostics/CodeAnalysis/NullableAttributes.cs",
+        "//src/libraries/System.Private.CoreLib:src/System/Runtime/CompilerServices/IsExternalInit.cs",
+        "//src/libraries/System.Private.CoreLib:src/System/Index.cs",
+
+        "//src/libraries/Common:src/Roslyn/DiagnosticDescriptorHelper.cs",
+        "//src/libraries/Common:src/Roslyn/GetBestTypeByMetadataName.cs",
+        "//src/libraries/Common:src/System/SR.cs",
+
+        "gen/Common/OperationExtensions.cs",
+        "gen/Common/ConvertToSourceGeneratedInteropFixer.cs",
+        "gen/Common/FixAllContextExtensions.cs",
+        "gen/Common/UnreachableException.cs",
+
+        # Production source included in the generator
+        "src/System/Runtime/InteropServices/Marshalling/ComInterfaceOptions.cs",
+
+        # Test common source
+        "tests/Common/ExceptionMarshalling.cs",
+    ],
+    target_frameworks = ["netstandard2.0"],
+    langversion = "preview",
+    cls_compliant = False,
+    nullable = "annotations",
+    allow_unsafe_blocks = True,
+    defines = ["MICROSOFT_INTEROP_COMINTERFACEGENERATOR", "BAZEL"],
+    deps = [
+        ":Microsoft.Interop.SourceGeneration",
+        "@paket.main//microsoft.codeanalysis.common",
+        "@paket.main//microsoft.codeanalysis.csharp",
+        "@paket.main//microsoft.codeanalysis.workspaces.common",
+        "@paket.main//microsoft.codeanalysis.csharp.workspaces",
+        "@paket.main//system.composition.attributedmodel",
+        "@paket.main//system.collections.immutable",
+        "@paket.main//system.memory",
+    ],
+    resx_file = "gen/Common/Resources/Strings.resx",
+    nowarn = [
+        "CS3003",
+        # MSBuild does not generate XML docs for generator projects
+        "CS1574",
+    ],
+    visibility = ["//visibility:public"],
+)
+
 netcoreapp_ref_assembly(
     name = "ref_System.Runtime.InteropServices",
     srcs = [

diff --git a/...System.Runtime.InteropServices/tests/System.Runtime.InteropServices.UnitTests/BUILD.bazel b/...System.Runtime.InteropServices/tests/System.Runtime.InteropServices.UnitTests/BUILD.bazel
@@ -0,0 +1,65 @@
+load("//src/tests:live_test.bzl", "library_test")
+
+library_test(
+    name = "System.Runtime.InteropServices.Tests",
+    srcs = glob(
+        ["**/*.cs"],
+        exclude = [
+            # Windows-specific tests
+            "System/Runtime/InteropServices/ComAwareEventInfoTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/ChangeWrapperHandleStrengthTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/CreateWrapperOfTypeTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/FinalReleaseComObjectTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GenerateGuidForTypeTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GenerateProgIdForTypeTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GetComObjectDataTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GetIDispatchForObjectTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GetNativeVariantForObjectTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GetObjectForIUnknownTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GetObjectForNativeVariantTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GetStartComSlotTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GetTypedObjectForIUnknownTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GetUniqueObjectForIUnknownTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/IsComObjectTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/IsTypeVisibleFromComTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/QueryInterfaceTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/ReleaseComObjectTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/SetComObjectDataTests.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/Common/CommonTypes.Windows.cs",
+            "System/Runtime/InteropServices/Marshal/GetEndComSlotTests.Windows.cs",
+            "System/Runtime/InteropServices/PosixSignalRegistrationTests.Windows.cs",
+            # Not included in the MSBuild project file
+            "System/Runtime/InteropServices/Marshalling/ComObjectTests.cs",
+            # Needs System.Drawing.Primitives (not yet in Bazel)
+            "System/Runtime/InteropServices/Marshal/GetNativeVariantForObjectTests.cs",
+            "System/Runtime/InteropServices/Marshal/GetObjectForNativeVariantTests.cs",
+            "System/Runtime/InteropServices/Marshal/GetObjectsForNativeVariantsTests.cs",
+        ],
+    ) + [
+        "//src/libraries/Common/tests:System/GenericMathHelpers.cs",
+        "//src/libraries/Common:src/Interop/Unix/Interop.Libraries.cs",
+    ],
+    deps = [
+        "//src/libraries/System.Threading:ref_System.Threading",
+        "//src/libraries/System.Threading.Thread:ref_System.Threading.Thread",
+        "//src/libraries/System.Reflection.Emit:ref_System.Reflection.Emit",
+        "//src/libraries/System.Reflection.Emit.ILGeneration:ref_System.Reflection.Emit.ILGeneration",
+        "//src/libraries:ref_Microsoft.Win32.Primitives",
+        "//src/libraries/System.Collections.Concurrent:ref_System.Collections.Concurrent",
+        "//src/libraries/System.Collections.Immutable:ref_System.Collections.Immutable",
+        "//src/libraries/System.Runtime.Numerics:ref_System.Runtime.Numerics",
+        "//src/libraries/Common/tests:TestUtilities",
+        "@paket.main//microsoft.dotnet.remoteexecutor",
+        "@paket.main//microsoft.dotnet.xunitassert",
+        "@paket.main//microsoft.dotnet.xunitextensions",
+        "@paket.main//xunit.abstractions",
+        "@paket.main//xunit.extensibility.core",
+    ],
+    analyzers = [
+        "//src/libraries/System.Runtime.InteropServices:ComInterfaceGenerator",
+        "//src/libraries/System.Runtime.InteropServices:Microsoft.Interop.SourceGeneration",
+    ],
+    allow_unsafe_blocks = True,
+    size = "large",
+    keyfile = "@nuget.microsoft.dotnet.arcade.sdk.v10.0.0-beta.26102.102//:tools/snk/Open.snk",
+)
diff --git a/src/libraries/System.Runtime.Intrinsics/tests/BUILD.bazel b/src/libraries/System.Runtime.Intrinsics/tests/BUILD.bazel
@@ -0,0 +1,30 @@
+load("//src/tests:live_test.bzl", "library_test")
+
+library_test(
+    name = "System.Runtime.Intrinsics.Tests",
+    srcs = glob(
+        ["**/*.cs"],
+        exclude = [
+            # Wasm-specific tests (require PackedSimd hardware support)
+            "Wasm/**",
+        ],
+    ) + [
+        "//src/libraries/Common/tests:System/GenericMathTestMemberData.cs",
+    ],
+    deps = [
+        "//src/libraries/System.Runtime.Numerics:ref_System.Runtime.Numerics",
+        "//src/libraries/Common/tests:TestUtilities",
+        "@paket.main//microsoft.dotnet.remoteexecutor",
+        "@paket.main//microsoft.dotnet.xunitassert",
+        "@paket.main//microsoft.dotnet.xunitextensions",
+        "@paket.main//xunit.abstractions",
+        "@paket.main//xunit.extensibility.core",
+    ],
+    allow_unsafe_blocks = True,
+    nowarn = [
+        "1718",
+        "SYSLIB0013",
+    ],
+    size = "large",
+    keyfile = "@nuget.microsoft.dotnet.arcade.sdk.v10.0.0-beta.26102.102//:tools/snk/Open.snk",
+)
diff --git a/src/libraries/System.Threading.Overlapped/tests/BUILD.bazel b/src/libraries/System.Threading.Overlapped/tests/BUILD.bazel
@@ -0,0 +1,23 @@
+load("//src/tests:live_test.bzl", "library_test")
+
+library_test(
+    name = "System.Threading.Overlapped.Tests",
+    srcs = glob(["*.cs"]) + [
+        "//src/libraries/Common/tests:System/Threading/ThreadTestHelpers.cs",
+    ],
+    deps = [
+        "//src/libraries/System.Threading.Overlapped:ref_System.Threading.Overlapped",
+        "//src/libraries/System.Threading:ref_System.Threading",
+        "//src/libraries/System.Threading.Thread:ref_System.Threading.Thread",
+        "//src/libraries/System.Threading.ThreadPool:ref_System.Threading.ThreadPool",
+        "//src/libraries:ref_Microsoft.Win32.Primitives",
+        "//src/libraries/Common/tests:TestUtilities",
+        "@paket.main//microsoft.dotnet.remoteexecutor",
+        "@paket.main//microsoft.dotnet.xunitassert",
+        "@paket.main//microsoft.dotnet.xunitextensions",
+        "@paket.main//xunit.abstractions",
+        "@paket.main//xunit.extensibility.core",
+    ],
+    allow_unsafe_blocks = True,
+    keyfile = "@nuget.microsoft.dotnet.arcade.sdk.v10.0.0-beta.26102.102//:tools/snk/Open.snk",
+)
diff --git a/src/libraries/System.Threading.Tasks.Parallel/tests/BUILD.bazel b/src/libraries/System.Threading.Tasks.Parallel/tests/BUILD.bazel
@@ -0,0 +1,27 @@
+load("//src/tests:live_test.bzl", "library_test")
+
+library_test(
+    name = "System.Threading.Tasks.Parallel.Tests",
+    srcs = glob(["*.cs"]) + [
+        "//src/libraries/Common/tests:System/Diagnostics/Tracing/TestEventListener.cs",
+        "//src/libraries/Common/tests:System/Threading/ThreadPoolHelpers.cs",
+    ],
+    deps = [
+        "//src/libraries/System.Threading.Tasks.Parallel:ref_System.Threading.Tasks.Parallel",
+        "//src/libraries/System.Threading:ref_System.Threading",
+        "//src/libraries/System.Threading.Thread:ref_System.Threading.Thread",
+        "//src/libraries/System.Threading.ThreadPool:ref_System.Threading.ThreadPool",
+        "//src/libraries/System.Collections.Concurrent:ref_System.Collections.Concurrent",
+        "//src/libraries/System.Collections.Immutable:ref_System.Collections.Immutable",
+        "//src/libraries/System.Runtime.Numerics:ref_System.Runtime.Numerics",
+        "//src/libraries/System.Diagnostics.Tracing:ref_System.Diagnostics.Tracing",
+        "//src/libraries/Common/tests:TestUtilities",
+        "@paket.main//microsoft.dotnet.remoteexecutor",
+        "@paket.main//microsoft.dotnet.xunitassert",
+        "@paket.main//microsoft.dotnet.xunitextensions",
+        "@paket.main//xunit.abstractions",
+        "@paket.main//xunit.extensibility.core",
+    ],
+    size = "large",
+    keyfile = "@nuget.microsoft.dotnet.arcade.sdk.v10.0.0-beta.26102.102//:tools/snk/Open.snk",
+)