[Android] Support static linking of CoreCLR on Android

src/coreclr/dlls/mscoree/coreclr/CMakeLists.txt

@@ -194,6 +194,14 @@ target_compile_definitions(coreclr_static PUBLIC CORECLR_EMBEDDED)
 if (CLR_CMAKE_HOST_ANDROID)
     target_link_libraries(coreclr PUBLIC log)
     target_link_libraries(coreclr_static PUBLIC log)
+    target_sources(coreclr_static PUBLIC
+        $<TARGET_OBJECTS:coreclrminipal_objects>
+        $<TARGET_OBJECTS:eventprovider_objects>
+        $<TARGET_OBJECTS:gc_pal_objects>
+        $<TARGET_OBJECTS:libunwind>
+        $<TARGET_OBJECTS:minipal_objects>
+        $<TARGET_OBJECTS:nativeresourcestring_objects>
+    )
 endif()
 
 if(CLR_CMAKE_TARGET_WIN32)
@@ -229,7 +237,7 @@ endif(CLR_CMAKE_TARGET_WIN32)
 
 # add the install targets
 install_clr(TARGETS coreclr DESTINATIONS . sharedFramework COMPONENT runtime)
-if(CLR_CMAKE_HOST_MACCATALYST OR CLR_CMAKE_HOST_IOS)
+if(CLR_CMAKE_HOST_MACCATALYST OR CLR_CMAKE_HOST_IOS OR CLR_CMAKE_HOST_ANDROID)
     install_clr(TARGETS coreclr_static DESTINATIONS . sharedFramework COMPONENT runtime)
 endif()
 

src/coreclr/gc/unix/CMakeLists.txt

@@ -10,4 +10,8 @@ set(GC_PAL_SOURCES
     events.cpp
     cgroup.cpp)
 
+if (CLR_CMAKE_HOST_ANDROID)
+    add_library(gc_pal_objects OBJECT ${GC_PAL_SOURCES} ${VERSION_FILE_PATH})
+endif()
+
 add_library(gc_pal STATIC ${GC_PAL_SOURCES} ${VERSION_FILE_PATH})

src/coreclr/gc/vxsort/CMakeLists.txt

@@ -26,4 +26,4 @@ set (VXSORT_SOURCES
   do_vxsort.h
 )
 
-add_library(gc_vxsort STATIC ${VXSORT_SOURCES})
+add_library(gc_vxsort OBJECT ${VXSORT_SOURCES})

src/coreclr/minipal/Unix/CMakeLists.txt

@@ -3,6 +3,13 @@ set(SOURCES
     dn-u16.cpp
 )
 
+if (CLR_CMAKE_HOST_ANDROID)
+    add_library(coreclrminipal_objects
+        OBJECT
+        ${SOURCES}
+    )
+endif()
+
 add_library(coreclrminipal
     STATIC
     ${SOURCES}

src/coreclr/nativeresources/CMakeLists.txt

@@ -1,5 +1,12 @@
 project(nativeresourcestring)
 
+if (CLR_CMAKE_HOST_ANDROID)
+  add_library_clr(nativeresourcestring_objects
+    OBJECT
+    resourcestring.cpp
+  )
+endif()
+
 add_library_clr(nativeresourcestring
   STATIC
   resourcestring.cpp

src/coreclr/pal/src/CMakeLists.txt

@@ -361,3 +361,9 @@ endif(FEATURE_EVENT_TRACE)
 
 # Install the static PAL library for VS
 install_clr (TARGETS coreclrpal DESTINATIONS lib)
+
+# Install the static PAL library for the runtime pack
+# The libcoreclrpal.a is linked using -Wl,--whole-archive as a separate static library
+if(CLR_CMAKE_HOST_ANDROID)
+    install_clr(TARGETS coreclrpal DESTINATIONS . sharedFramework)
+endif()

src/coreclr/pal/src/eventprovider/dummyprovider/CMakeLists.txt

@@ -31,6 +31,13 @@ add_custom_command(OUTPUT ${DUMMY_PROVIDER_SOURCES}
   COMMAND ${GENERATE_COMMAND}
   DEPENDS ${EVENT_MANIFEST} ${GENERATE_SCRIPT})
 
+if (CLR_CMAKE_HOST_ANDROID)
+    add_library(eventprovider_objects
+        OBJECT
+        ${DUMMY_PROVIDER_SOURCES}
+    )
+endif()
+
 add_library(eventprovider
     STATIC
     ${DUMMY_PROVIDER_SOURCES}

src/installer/pkg/sfx/Microsoft.NETCore.App/Directory.Build.props

@@ -102,6 +102,7 @@
     <PlatformManifestFileEntry Include="libcoreclr.so" IsNative="true" />
     <PlatformManifestFileEntry Include="libcoreclr.dylib" IsNative="true" />
     <PlatformManifestFileEntry Include="libcoreclr_static.a" IsNative="true" />
+    <PlatformManifestFileEntry Include="libcoreclrpal.a" IsNative="true" />
     <PlatformManifestFileEntry Include="clrgc.dll" IsNative="true" />
     <PlatformManifestFileEntry Include="libclrgc.so" IsNative="true" />
     <PlatformManifestFileEntry Include="libclrgc.dylib" IsNative="true" />

src/mono/msbuild/android/build/AndroidBuild.props

@@ -10,10 +10,11 @@
     <_HostOS Condition="$([MSBuild]::IsOSPlatform('Windows'))">windows</_HostOS>
     <_HostOS Condition="$([MSBuild]::IsOSPlatform('OSX'))">osx</_HostOS>
     <_HostOS Condition="'$(_HostOS)' == ''">linux</_HostOS>
-
     <_IsLibraryMode Condition="'$(UseMonoRuntime)' == 'true' and '$(UseNativeAOTRuntime)' != 'true' and '$(NativeLib)' != ''">true</_IsLibraryMode>
     <_ReadRuntimeComponentsManifestTargetName Condition="'$(UseMonoRuntime)' == 'true' and '$(UseNativeAOTRuntime)' != 'true'">_MonoReadAvailableComponentsManifest</_ReadRuntimeComponentsManifestTargetName>
 
+    <StaticLinkedRuntime Condition="'$(RuntimeFlavor)' == 'coreclr' and '$(StaticLinkedRuntime)' == ''">false</StaticLinkedRuntime>
+
     <AndroidBuildAfterThisTarget Condition="'$(AndroidBuildAfterThisTarget)' == ''">Publish</AndroidBuildAfterThisTarget>
     <AndroidBuildDependsOn Condition="'$(UseMonoRuntime)' == 'true'">
         $(_ReadRuntimeComponentsManifestTargetName);
@@ -41,4 +42,4 @@
   <Import Condition="'$(UseNativeAOTRuntime)' != 'true' and '$(UseMonoRuntime)' == 'true'" Project="$(_CommonTargetsDir)CommonMobileBuild.props" />
   <Import Condition="'$(UseNativeAOTRuntime)' != 'true' and '$(UseMonoRuntime)' == 'true'" Project="$(_CommonTargetsDir)RuntimeComponentManifest.targets" />
   <Import Condition="'$(UseNativeAOTRuntime)' != 'true' and ('$(UseMonoRuntime)' == 'true' and '$(RunAOTCompilation)' == 'true')" Project="$(_CommonTargetsDir)MonoAOTCompiler.props" />
-</Project>
+</Project>

src/mono/msbuild/android/build/AndroidBuild.targets

@@ -259,7 +259,8 @@
         ProjectName="$(AppName)"
         RuntimeComponents="@(RuntimeComponents)"
         RuntimeIdentifier="$(RuntimeIdentifier)"
-        StripDebugSymbols="$(StripDebugSymbols)">
+        StripDebugSymbols="$(StripDebugSymbols)"
+        StaticLinkedRuntime="$(StaticLinkedRuntime)">
         <Output TaskParameter="ApkBundlePath" PropertyName="ApkBundlePath" />
         <Output TaskParameter="ApkPackageId"  PropertyName="ApkPackageId" />
     </AndroidAppBuilderTask>

src/mono/sample/Android/Makefile

@@ -9,6 +9,7 @@ DEPLOY_AND_RUN?=true
 RUNTIME_FLAVOR?=mono
 R2R?=false
 R2R_COMPOSITE?=false
+STATIC_LINKING?=false
 
 #If DIAGNOSTIC_PORTS is enabled, @(RuntimeComponents) must also include 'diagnostics_tracing'.
 #If @(RuntimeComponents) includes 'diagnostics_tracing', DIAGNOSTIC_PORTS is optional.
@@ -57,7 +58,8 @@ run: appbuilder
 	/p:RuntimeFlavor=$(RUNTIME_FLAVOR) \
 	/p:PublishReadyToRun=$(R2R) \
 	/p:PublishReadyToRunComposite=$(R2R_COMPOSITE) \
+	/p:StaticLinkedRuntime=$(STATIC_LINKING) \
 	/bl
 clean:
 	rm -rf $(REPO_DIR)/artifacts/bin/AndroidSampleApp
-	rm -rf $(REPO_DIR)/artifacts/obj/mono/AndroidSampleApp
+	rm -rf $(REPO_DIR)/artifacts/obj/mono/AndroidSampleApp

src/tasks/AndroidAppBuilder/ApkBuilder.cs

@@ -120,11 +120,6 @@ public ApkBuilder(TaskLoggingHelper logger)
             throw new ArgumentException($"Using DiagnosticPorts targeting Mono requires diagnostics_tracing runtime component, which was not included in 'RuntimeComponents' item group. @RuntimeComponents: '{string.Join(", ", RuntimeComponents)}'");
         }
 
-        if (IsCoreCLR && StaticLinkedRuntime)
-        {
-            throw new ArgumentException("Static linking is not supported for CoreCLR runtime");
-        }
-
         AndroidSdkHelper androidSdkHelper = new AndroidSdkHelper(AndroidSdk, BuildApiLevel, BuildToolsVersion);
 
         if (string.IsNullOrEmpty(MinApiLevel))
@@ -263,6 +258,10 @@ public ApkBuilder(TaskLoggingHelper logger)
             {
                 runtimeLib = Path.Combine(AppDir, "libmonosgen-2.0.so");
             }
+            else if (StaticLinkedRuntime && IsCoreCLR)
+            {
+                runtimeLib = Path.Combine(AppDir, "libcoreclr_static.a");
+            }
             else if (IsCoreCLR)
             {
                 runtimeLib = Path.Combine(AppDir, "libcoreclr.so");
@@ -277,7 +276,7 @@ public ApkBuilder(TaskLoggingHelper logger)
                 nativeLibraries += $"{runtimeLib}{Environment.NewLine}";
             }
 
-            if (StaticLinkedRuntime)
+            if (StaticLinkedRuntime && IsMono)
             {
                 string[] staticComponentStubLibs = Directory.GetFiles(AppDir, "libmono-component-*-stub-static.a");
 
@@ -313,12 +312,35 @@ public ApkBuilder(TaskLoggingHelper logger)
             }
         }
 
+        if (StaticLinkedRuntime && IsCoreCLR)
+        {
+            string[] staticLibs = Directory.GetFiles(AppDir, "*.a")
+                .Where(lib => !Path.GetFileName(lib).Equals("libcoreclr_static.a", StringComparison.OrdinalIgnoreCase))
+                .ToArray();
+
+            foreach (string lib in staticLibs)
+            {
+                nativeLibraries += $"    {lib}{Environment.NewLine}";
+            }
+
+            nativeLibraries += $"    libc++abi.a{Environment.NewLine}";
+            nativeLibraries += $"    libc++_static.a{Environment.NewLine}";
+        }
+
         StringBuilder extraLinkerArgs = new StringBuilder();
         foreach (ITaskItem item in ExtraLinkerArguments)
         {
             extraLinkerArgs.AppendLine($"    \"{item.ItemSpec}\"");
         }
 
+        if (StaticLinkedRuntime && IsCoreCLR)
+        {
+            // Ensure global symbol references in the shared library are resolved to definitions in
+            // the same shared library. For the static linked runtime specifically, we need this for
+            // global functions in assembly for the linker to treat relative offsets to them as constant
+            extraLinkerArgs.AppendLine($"    \"-Wl,-Bsymbolic\"");
+        }
+
         nativeLibraries += assemblerFilesToLink.ToString();
 
         string aotSources = assemblerFiles.ToString();
@@ -401,7 +423,8 @@ public ApkBuilder(TaskLoggingHelper logger)
             envVariables += $"\t\tsetEnv(\"{name}\", \"{value}\");\n";
         }
 
-        string jniLibraryName = (IsLibraryMode) ? ProjectName! : "System.Security.Cryptography.Native.Android";
+        string jniLibraryName = (IsLibraryMode) ? ProjectName! :
+            (StaticLinkedRuntime && IsCoreCLR) ? "monodroid" : "System.Security.Cryptography.Native.Android";
         string monoRunner = Utils.GetEmbeddedResource("MonoRunner.java")
             .Replace("%EntryPointLibName%", Path.GetFileName(mainLibraryFileName))
             .Replace("%JNI_LIBRARY_NAME%", jniLibraryName)
@@ -461,7 +484,8 @@ public ApkBuilder(TaskLoggingHelper logger)
                     excludedLibs.Add("libmscordaccore.so");
                 }
             }
-            dynamicLibs.AddRange(Directory.GetFiles(AppDir, "*.so").Where(file => !excludedLibs.Contains(Path.GetFileName(file))));
+            if (!StaticLinkedRuntime)
+                dynamicLibs.AddRange(Directory.GetFiles(AppDir, "*.so").Where(file => !excludedLibs.Contains(Path.GetFileName(file))));
         }
 
         // add all *.so files to lib/%abi%/

src/tasks/AndroidAppBuilder/Templates/monodroid-coreclr.c

@@ -157,7 +157,7 @@ free_resources ()
     }
     if (g_executable_path)
     {
-        free (g_executable_path);
+        free ((void*)g_executable_path);
         g_executable_path = NULL;
     }
     if (g_coreclr_handle)