[Android] Add NdkToolFinder task & Fix up AOT app build (#88210)

Since we bumped to NDK 23, having the aot compiler itself generate shared libraries stopped working. This is due to NDK 23 moving most of the toolchain into a common bin directory. AS was left over in each of these directories as an alias to bin/<triple>-as.

This change adds a task to collect all of the important NDK toolchain paths. It also fixes up the aot build when AOTWithLibraryFiles is set to true and we want the aot compiler to produce shared libraries.

Directory.Build.props

@@ -149,6 +149,7 @@
 
     <AppleAppBuilderDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'AppleAppBuilder', 'Debug', '$(NetCoreAppToolCurrent)'))</AppleAppBuilderDir>
     <AndroidAppBuilderDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'AndroidAppBuilder', 'Debug', '$(NetCoreAppToolCurrent)', 'publish'))</AndroidAppBuilderDir>
+    <MobileBuildTasksDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'MobileBuildTasks', 'Debug', '$(NetCoreAppToolCurrent)'))</MobileBuildTasksDir>
     <WasmAppBuilderDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'WasmAppBuilder', 'Debug', '$(NetCoreAppToolCurrent)'))</WasmAppBuilderDir>
     <WasmBuildTasksDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'WasmBuildTasks', 'Debug', '$(NetCoreAppToolCurrent)', 'publish'))</WasmBuildTasksDir>
     <WorkloadBuildTasksDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'WorkloadBuildTasks', 'Debug', '$(NetCoreAppToolCurrent)'))</WorkloadBuildTasksDir>
@@ -162,6 +163,7 @@
     <Crossgen2SdkOverrideTargetsPath Condition="'$(MSBuildRuntimeType)' == 'Core'">$([MSBuild]::NormalizePath('$(ArtifactsBinDir)', 'Crossgen2Tasks', 'Debug', '$(NetCoreAppToolCurrent)', 'Microsoft.NET.CrossGen.targets'))</Crossgen2SdkOverrideTargetsPath>
     <AppleAppBuilderTasksAssemblyPath>$([MSBuild]::NormalizePath('$(AppleAppBuilderDir)', 'AppleAppBuilder.dll'))</AppleAppBuilderTasksAssemblyPath>
     <AndroidAppBuilderTasksAssemblyPath>$([MSBuild]::NormalizePath('$(AndroidAppBuilderDir)', 'AndroidAppBuilder.dll'))</AndroidAppBuilderTasksAssemblyPath>
+    <MobileBuildTasksAssemblyPath>$([MSBuild]::NormalizePath('$(MobileBuildTasksDir)', 'MobileBuildTasks.dll'))</MobileBuildTasksAssemblyPath>
     <WasmAppBuilderTasksAssemblyPath>$([MSBuild]::NormalizePath('$(WasmAppBuilderDir)', 'WasmAppBuilder.dll'))</WasmAppBuilderTasksAssemblyPath>
     <WasmBuildTasksAssemblyPath>$([MSBuild]::NormalizePath('$(WasmBuildTasksDir)', 'WasmBuildTasks.dll'))</WasmBuildTasksAssemblyPath>
     <WasmAppHostDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'WasmAppHost', 'wasm', '$(Configuration)'))</WasmAppHostDir>

src/mono/mono/mini/aot-compiler.c

@@ -239,6 +239,7 @@ typedef struct MonoAotOptions {
 	gboolean deterministic;
 	gboolean allow_errors;
 	char *tool_prefix;
+	char *as_prefix;
 	char *ld_flags;
 	char *ld_name;
 	char *mtriple;
@@ -8825,6 +8826,8 @@ mono_aot_parse_options (const char *aot_options, MonoAotOptions *opts)
 			opts->nunbox_arbitrary_trampolines = atoi (arg + strlen ("nunbox-arbitrary-trampolines="));
 		} else if (str_begins_with (arg, "tool-prefix=")) {
 			opts->tool_prefix = g_strdup (arg + strlen ("tool-prefix="));
+		} else if (str_begins_with (arg, "as-prefix=")) {
+			opts->as_prefix = g_strdup (arg + strlen ("as-prefix="));
 		} else if (str_begins_with (arg, "ld-flags=")) {
 			opts->ld_flags = g_strdup (arg + strlen ("ld-flags="));
 		} else if (str_begins_with (arg, "ld-name=")) {
@@ -13123,6 +13126,7 @@ compile_asm (MonoAotCompile *acfg)
 	char *command, *objfile;
 	char *outfile_name, *tmp_outfile_name, *llvm_ofile;
 	const char *tool_prefix = acfg->aot_opts.tool_prefix ? acfg->aot_opts.tool_prefix : "";
+	const char *as_prefix = acfg->aot_opts.as_prefix ? acfg->aot_opts.as_prefix : tool_prefix;
 	char *ld_flags = acfg->aot_opts.ld_flags ? acfg->aot_opts.ld_flags : g_strdup("");
 
 #ifdef TARGET_WIN32_MSVC
@@ -13214,7 +13218,7 @@ compile_asm (MonoAotCompile *acfg)
 	g_string_append (acfg->as_args, "-c -x assembler ");
 #endif
 
-	command = g_strdup_printf ("\"%s%s\" %s %s -o %s %s", tool_prefix, AS_NAME, AS_OPTIONS,
+	command = g_strdup_printf ("\"%s%s\" %s %s -o %s %s", as_prefix, AS_NAME, AS_OPTIONS,
 			acfg->as_args ? acfg->as_args->str : "",
 			wrap_path (objfile), wrap_path (acfg->tmpfname));
 	aot_printf (acfg, "Executing the native assembler: %s\n", command);
@@ -13225,7 +13229,7 @@ compile_asm (MonoAotCompile *acfg)
 	}
 
 	if (acfg->llvm && !acfg->llvm_owriter) {
-		command = g_strdup_printf ("\"%s%s\" %s %s -o %s %s", tool_prefix, AS_NAME, AS_OPTIONS,
+		command = g_strdup_printf ("\"%s%s\" %s %s -o %s %s", as_prefix, AS_NAME, AS_OPTIONS,
 			acfg->as_args ? acfg->as_args->str : "",
 			wrap_path (acfg->llvm_ofile), wrap_path (acfg->llvm_sfile));
 		aot_printf (acfg, "Executing the native assembler: %s\n", command);
@@ -14222,6 +14226,7 @@ aot_opts_free (MonoAotOptions *aot_opts)
 	g_list_free (aot_opts->direct_pinvoke_lists);
 	g_free (aot_opts->dedup_include);
 	g_free (aot_opts->tool_prefix);
+	g_free (aot_opts->as_prefix);
 	g_free (aot_opts->ld_flags);
 	g_free (aot_opts->ld_name);
 	g_free (aot_opts->mtriple);

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

@@ -4,6 +4,10 @@
     <UseMonoRuntime>true</UseMonoRuntime>
     <UseMonoJustInterp Condition="'$(RunAOTCompilation)' == 'true' and '$(MonoForceInterpreter)' == 'true'">true</UseMonoJustInterp>
 
+    <_HostOS Condition="$([MSBuild]::IsOSPlatform('Windows'))">windows</_HostOS>
+    <_HostOS Condition="$([MSBuild]::IsOSPlatform('OSX'))">osx</_HostOS>
+    <_HostOS Condition="'$(_HostOS)' == ''">linux</_HostOS>
+
     <_IsLibraryMode Condition="'$(NativeLib)' != ''">true</_IsLibraryMode>
 
     <AndroidBuildAfterThisTarget Condition="'$(AndroidBuildAfterThisTarget)' == ''">Publish</AndroidBuildAfterThisTarget>

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

@@ -8,6 +8,9 @@
     <EnableDefaultAssembliesToBundle Condition="'$(EnableDefaultAssembliesToBundle)' == ''">false</EnableDefaultAssembliesToBundle>
   </PropertyGroup>
 
+  <UsingTask Condition="'$(RunAOTCompilation)' == 'true'"
+             TaskName="NdkToolFinderTask"
+             AssemblyFile="$(MobileBuildTasksAssemblyPath)" />
   <UsingTask Condition="'$(AndroidGenerateAppBundle)' == 'true'"
              TaskName="AndroidAppBuilderTask"
              AssemblyFile="$(AndroidAppBuilderTasksAssemblyPath)" />
@@ -37,7 +40,6 @@
 
       <BundleDir>$(AndroidBundleDir)</BundleDir>
       <_MonoHeaderPath>$([MSBuild]::NormalizeDirectory($(MicrosoftNetCoreAppRuntimePackRidNativeDir), 'include', 'mono-2.0'))</_MonoHeaderPath>
-      <_AotModuleTablePath>$(AndroidBundleDir)\modules.c</_AotModuleTablePath>
     </PropertyGroup>
 
     <PropertyGroup>
@@ -94,6 +96,15 @@
       <_AOTMode Condition="'$(UseMonoJustInterp)' != 'true'">Normal</_AOTMode>
       <_AOTMode Condition="'$(UseMonoJustInterp)' == 'true'">JustInterp</_AOTMode>
       <_AOTMode Condition="'$(ForceFullAOT)' == 'true'">Full</_AOTMode>
+      <_AotOutputType>AsmOnly</_AotOutputType>
+    </PropertyGroup>
+    <!-- Should consider renaming property to something more appropriate-->
+    <PropertyGroup Condition="'$(AOTWithLibraryFiles)' == 'true'">
+      <_AotOutputType>Library</_AotOutputType>
+      <_AotLibraryFormat>So</_AotLibraryFormat>
+    </PropertyGroup>
+    <PropertyGroup Condition="'$(AOTWithLibraryFiles)' != 'true'">
+      <_AotModuleTablePath>$(AndroidBundleDir)\modules.c</_AotModuleTablePath>
     </PropertyGroup>
 
     <PropertyGroup Condition="'$(_IsLibraryMode)' == 'true'">
@@ -126,6 +137,28 @@
       <ProcessArguments>@(MonoAOTCompilerDefaultProcessArguments, ';')</ProcessArguments>
     </PropertyGroup>
 
+    <PropertyGroup>
+      <AndroidLibraryMinApiLevel Condition="'$(AndroidLibraryMinApiLevel)' == ''">21</AndroidLibraryMinApiLevel>
+    </PropertyGroup>
+
+    <NdkToolFinderTask
+      Condition="'$(AOTWithLibraryFiles)' == 'true'"
+      Architecture="$(TargetArchitecture)"
+      HostOS="$(_HostOS)"
+      MinApiLevel="$(AndroidLibraryMinApiLevel)">
+      <Output TaskParameter="AsPrefixPath" PropertyName="_AsPrefixPath" />
+      <Output TaskParameter="ToolPrefixPath" PropertyName="_ToolPrefixPath" />
+      <Output TaskParameter="Triple" PropertyName="_Triple" />
+      <Output TaskParameter="LdName" PropertyName="_LdName" />
+      <Output TaskParameter="LdPath" PropertyName="_LdPath" />
+      <Output TaskParameter="ClangPath" PropertyName="_ClangPath" />
+    </NdkToolFinderTask>
+
+    <PropertyGroup Condition="'$(AOTWithLibraryFiles)' == 'true'">
+      <_AsPrefixPath>$([MSBuild]::EnsureTrailingSlash('$(_AsPrefixPath)'))</_AsPrefixPath>
+      <_ToolPrefixPath>$([MSBuild]::EnsureTrailingSlash('$(_ToolPrefixPath)'))</_ToolPrefixPath>
+    </PropertyGroup>
+
     <ItemGroup>
       <_AotInputAssemblies Include="@(_AssembliesToBundleInternal)"
                            Condition="'%(_AssembliesToBundleInternal._InternalForceInterpret)' != 'true'">
@@ -182,17 +215,20 @@
 
     <MonoAOTCompiler
         AotModulesTablePath="$(_AotModuleTablePath)"
+        AsPrefix="$(_AsPrefixPath)"
         Assemblies="@(_AotInputAssemblies)"
         CompilerBinaryPath="@(MonoAotCrossCompiler->WithMetadataValue('RuntimeIdentifier','$(TargetOS.ToLowerInvariant())-$(TargetArchitecture.ToLowerInvariant())'))"
         DirectPInvokes="@(DirectPInvokes)"
         DirectPInvokeLists="@(DirectPInvokeLists)"
         EnableUnmanagedCallersOnlyMethodsExport="$(_EnableUnmanagedCallersOnlyMethodsExport)"
         IntermediateOutputPath="$(_MobileIntermediateOutputPath)"
+        LibraryFormat="$(_AotLibraryFormat)"
         LLVMPath="$(MonoAotCrossDir)"
         MibcProfilePath="@(ProfiledAOTProfilePaths)"
         Mode="$(_AOTMode)"
         OutputDir="$(_MobileIntermediateOutputPath)"
-        OutputType="AsmOnly"
+        OutputType="$(_AotOutputType)"
+        ToolPrefix="$(_ToolPrefixPath)"
         UseAotDataFile="$(_UseAotDataFile)"
         UseLLVM="$(MonoEnableLLVM)">
         <Output TaskParameter="CompiledAssemblies" ItemName="_AssembliesToBundleInternal" />

src/mono/sample/Android/AndroidSampleApp.csproj

@@ -11,8 +11,13 @@
   </PropertyGroup>
 
   <Import Project="$(RepoTasksDir)AotCompilerTask\MonoAOTCompiler.props" />
-  <UsingTask TaskName="AndroidAppBuilderTask" AssemblyFile="$(AndroidAppBuilderTasksAssemblyPath)"/>
-  <UsingTask TaskName="MonoAOTCompiler" AssemblyFile="$(MonoAOTCompilerTasksAssemblyPath)" />
+  <UsingTask TaskName="AndroidAppBuilderTask" 
+             AssemblyFile="$(AndroidAppBuilderTasksAssemblyPath)"/>
+  <UsingTask TaskName="MonoAOTCompiler" 
+             AssemblyFile="$(MonoAOTCompilerTasksAssemblyPath)" />
+  <UsingTask Condition="'$(RunAOTCompilation)' == 'true'"
+             TaskName="NdkToolFinderTask"
+             AssemblyFile="$(MobileBuildTasksAssemblyPath)" />
 
   <PropertyGroup Condition="'$(RunAOTCompilation)' == 'true'">
     <_MobileIntermediateOutputPath>$(IntermediateOutputPath)mobile</_MobileIntermediateOutputPath>
@@ -36,46 +41,57 @@
              Condition="'$(ForceAOT)' == 'true'"/>
     <RemoveDir Directories="$(ApkDir)" />
 
-    <PropertyGroup>
-      <AndroidAbi Condition="'$(TargetArchitecture)' == 'arm64'">arm64-v8a</AndroidAbi>
-      <AndroidAbi Condition="'$(TargetArchitecture)' == 'arm'">armeabi-v7a</AndroidAbi>
-      <AndroidAbi Condition="'$(TargetArchitecture)' == 'x64'">x86_64</AndroidAbi>
-      <AndroidAbi Condition="'$(TargetArchitecture)' == 'x86'">x86</AndroidAbi>
-    </PropertyGroup>
-
     <Message Importance="High" Text="Path: $(PublishDir)" />
     <Message Importance="High" Text="SourceDir: $(OutputPath)" />
 
+    <PropertyGroup Condition="'$(ForceAOT)' == 'true' and '$(AOTWithLibraryFiles)' == 'true'">
+      <_AotOutputType>Library</_AotOutputType>
+      <_AotLibraryFormat>So</_AotLibraryFormat>
+      <_AotMode Condition="'$(AotMode)' == ''">Normal</_AotMode>
+    </PropertyGroup>
+
     <PropertyGroup Condition="'$(ForceAOT)' == 'true' and '$(AOTWithLibraryFiles)' != 'true'">
       <_AotOutputType>AsmOnly</_AotOutputType>
       <_AotModulesTablePath>$(ApkDir)\modules.c</_AotModulesTablePath>
+      <_AotMode Condition="'$(AotMode)' == ''">Full</_AotMode>
     </PropertyGroup>
 
-    <PropertyGroup Condition="'$(ForceAOT)' == 'true' and '$(AOTWithLibraryFiles)' == 'true'">
-      <_AotOutputType>Library</_AotOutputType>
-      <_AotLibraryFormat>So</_AotLibraryFormat>
-      <_PrebuiltOS Condition="$([MSBuild]::IsOSPlatform('Linux'))">linux-x86_64</_PrebuiltOS>
-      <_PrebuiltOS Condition="$([MSBuild]::IsOSPlatform('OSX'))">darwin-x86_64</_PrebuiltOS>
-      <_PrebuiltOS Condition="$([MSBuild]::IsOSPlatform('Windows'))">windows-x86_64</_PrebuiltOS>
-      <_PrebuiltAbi Condition="'$(TargetArchitecture)' == 'arm'">arm-linux-androideabi$</_PrebuiltAbi>
-      <_PrebuiltAbi Condition="'$(TargetArchitecture)' == 'arm64'">aarch64-linux-android</_PrebuiltAbi>
-      <_PrebuiltAbi Condition="'$(TargetArchitecture)' == 'x64'">x86_64-linux-android</_PrebuiltAbi>
-      <_PrebuiltAbi Condition="'$(TargetArchitecture)' == 'x86'">i686-linux-android</_PrebuiltAbi>
-      <_AotToolPrefix>$(ANDROID_NDK_ROOT)\toolchains\llvm\prebuilt\$(_PrebuiltOS)\bin\$(_PrebuiltAbi)-</_AotToolPrefix>
+    <PropertyGroup>
+      <AndroidLibraryMinApiLevel Condition="'$(AndroidLibraryMinApiLevel)' == ''">21</AndroidLibraryMinApiLevel>
+    </PropertyGroup>
+
+    <NdkToolFinderTask
+      Condition="'$(AOTWithLibraryFiles)' == 'true'"
+      Architecture="$(TargetArchitecture)"
+      HostOS="$(_HostOS)"
+      MinApiLevel="$(AndroidLibraryMinApiLevel)">
+      <Output TaskParameter="AsPrefixPath" PropertyName="_AsPrefixPath" />
+      <Output TaskParameter="ToolPrefixPath" PropertyName="_ToolPrefixPath" />
+      <Output TaskParameter="Triple" PropertyName="_Triple" />
+      <Output TaskParameter="LdName" PropertyName="_LdName" />
+      <Output TaskParameter="LdPath" PropertyName="_LdPath" />
+      <Output TaskParameter="ClangPath" PropertyName="_ClangPath" />
+    </NdkToolFinderTask>
+
+    <PropertyGroup Condition="'$(AOTWithLibraryFiles)' == 'true'">
+      <_AsPrefixPath>$([MSBuild]::EnsureTrailingSlash('$(_AsPrefixPath)'))</_AsPrefixPath>
+      <_ToolPrefixPath>$([MSBuild]::EnsureTrailingSlash('$(_ToolPrefixPath)'))</_ToolPrefixPath>
     </PropertyGroup>
 
     <MonoAOTCompiler Condition="'$(ForceAOT)' == 'true'"
+        AotModulesTablePath="$(_AotModulesTablePath)"
+        AsPrefix="$(_AsPrefixPath)"
+        Assemblies="@(AotInputAssemblies)"
         CompilerBinaryPath="@(MonoAotCrossCompiler->WithMetadataValue('RuntimeIdentifier','$(TargetOS)-$(TargetArchitecture.ToLowerInvariant())'))"
+        IntermediateOutputPath="$(IntermediateOutputPath)"
+        LibraryFormat="$(_AotLibraryFormat)"
+        LLVMPath="$(MonoAotCrossDir)"
+        Mode="$(_AotMode)"
         OutputDir="$(_MobileIntermediateOutputPath)"
-        Mode="Full"
         OutputType="$(_AotOutputType)"
-        Assemblies="@(AotInputAssemblies)"
-        AotModulesTablePath="$(_AotModulesTablePath)"
-        ToolPrefix="$(_AotToolPrefix)"
-        LibraryFormat="$(_AotLibraryFormat)"
-        IntermediateOutputPath="$(IntermediateOutputPath)"
-        UseLLVM="$(UseLLVM)"
-        LLVMPath="$(MonoAotCrossDir)">
+        ToolPrefix="$(_ToolPrefixPath)"
+        UseAotDataFile="false"
+        UseLLVM="$(UseLLVM)">
         <Output TaskParameter="CompiledAssemblies" ItemName="BundleAssemblies" />
     </MonoAOTCompiler>
 

src/mono/sample/Android/Makefile

@@ -35,6 +35,5 @@ run:
 	/p:RunActivity=false \
 	'/p:RuntimeComponents="$(RUNTIME_COMPONENTS)"' \
 	'/p:DiagnosticPorts="$(DIAGNOSTIC_PORTS)"'
-
 clean:
 	rm -rf ../../../../artifacts/bin/AndroidSampleApp

src/tasks/AotCompilerTask/MonoAOTCompiler.cs

@@ -231,6 +231,11 @@ public class MonoAOTCompiler : Microsoft.Build.Utilities.Task
     /// </summary>
     public string? ToolPrefix { get; set; }
 
+    /// <summary>
+    /// Prepends a prefix to the name of the assembler (as) tool ran by the AOT compiler.
+    /// </summary>
+    public string? AsPrefix { get; set; }
+
     /// <summary>
     /// Path to the directory where msym artifacts are stored.
     /// </summary>
@@ -723,6 +728,11 @@ private PrecompileArguments GetPrecompileArgumentsFor(ITaskItem assemblyItem, st
             aotArgs.Add($"tool-prefix={ToolPrefix}");
         }
 
+        if (!string.IsNullOrEmpty(AsPrefix))
+        {
+            aotArgs.Add($"as-prefix={AsPrefix}");
+        }
+
         string assemblyFilename = Path.GetFileName(assembly);
 
         if (isDedup)
@@ -845,7 +855,11 @@ private PrecompileArguments GetPrecompileArgumentsFor(ITaskItem assemblyItem, st
                 ProxyFile proxyFile = _cache.NewFile(llvmObjectFile);
                 proxyFiles.Add(proxyFile);
                 aotArgs.Add($"llvm-outfile={proxyFile.TempFile}");
-                aotAssembly.SetMetadata("LlvmObjectFile", proxyFile.TargetFile);
+
+                if (UseStaticLinking)
+                {
+                    aotAssembly.SetMetadata("LlvmObjectFile", proxyFile.TargetFile);
+                }
             }
         }
 

src/tasks/Common/Utils.cs

@@ -345,6 +345,15 @@ public static void DirectoryCopy(string sourceDir, string destDir, Func<string,
     }
 #endif
 
+    public static bool IsWindows()
+    {
+#if NETCOREAPP
+        return OperatingSystem.IsWindows();
+#else
+        return true;
+#endif
+    }
+
     public static bool IsManagedAssembly(string filePath)
     {
         if (!File.Exists(filePath))

src/tasks/MobileBuildTasks/Android/Ndk/AndroidArch.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+
+namespace Microsoft.Android.Build.Ndk
+{
+    public sealed class AndroidArch(string archName, string abi, string triple)
+    {
+        public string ArchName { get; set; } = archName;
+
+        public string Abi { get; set; } = abi;
+
+        public string Triple { get; set; } = triple;
+    }
+}