feat(hle): prefer loaded guest exports for selected registrations (#844)

Co-authored-by: Acelogic <miguelc4600@gmail.com>

tests/SharpEmu.Libs.Tests/Cpu/DirectExecutionBackendLlePreferenceTests.cs

@@ -0,0 +1,60 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.Core.Cpu.Native;
+using SharpEmu.HLE;
+using Xunit;
+
+namespace SharpEmu.Libs.Tests.Cpu;
+
+public sealed class DirectExecutionBackendLlePreferenceTests
+{
+    [Fact]
+    public void ExplicitLlePreference_AllowsNonKernelRegisteredExport()
+    {
+        var export = Export("libSceNpCppWebApi", preferLle: true);
+
+        Assert.True(DirectExecutionBackend.ShouldResolveRegisteredExportViaLle(
+            export,
+            preferLleForLibc: false));
+    }
+
+    [Fact]
+    public void ExplicitLlePreference_CannotOverrideKernelHleBoundary()
+    {
+        var export = Export("libKernel", preferLle: true);
+
+        Assert.False(DirectExecutionBackend.ShouldResolveRegisteredExportViaLle(
+            export,
+            preferLleForLibc: true));
+    }
+
+    [Fact]
+    public void RegisteredExportWithoutLlePreference_RemainsHle()
+    {
+        var export = Export("libSceNpCppWebApi", preferLle: false);
+
+        Assert.False(DirectExecutionBackend.ShouldResolveRegisteredExportViaLle(
+            export,
+            preferLleForLibc: false));
+    }
+
+    [Fact]
+    public void ExistingLibcPolicy_CanStillSelectRegisteredFirmwareExport()
+    {
+        var export = Export("libSceLibcInternal", preferLle: false);
+
+        Assert.True(DirectExecutionBackend.ShouldResolveRegisteredExportViaLle(
+            export,
+            preferLleForLibc: true));
+    }
+
+    private static ExportedFunction Export(string libraryName, bool preferLle) =>
+        new(
+            libraryName,
+            "Zxa0VhQVTsk",
+            "sceKernelWaitSema",
+            Generation.Gen5,
+            static _ => 0,
+            preferLle);
+}

tests/SharpEmu.SourceGenerators.Tests/SysAbiExportAnalyzerTests.cs

@@ -53,6 +53,40 @@ public sealed class SysAbiExportAnalyzerTests
         AssertSingle(diagnostics, "SHEM001");
     }
 
+    [Fact]
+    public void DuplicateNidOnTheSameMultiAttributeHandlerIsReported()
+    {
+        var diagnostics = Analyze("""
+            using SharpEmu.HLE;
+
+            public static class Exports
+            {
+                [SysAbiExport(Nid = "Zxa0VhQVTsk", ExportName = "sceKernelWaitSema")]
+                [SysAbiExport(Nid = "Zxa0VhQVTsk", ExportName = "sceKernelWaitSema")]
+                public static int Shared(CpuContext ctx) => 0;
+            }
+            """);
+
+        AssertSingle(diagnostics, "SHEM001");
+    }
+
+    [Fact]
+    public void EveryAttributeOnAMultiAttributeHandlerIsAnalyzed()
+    {
+        var diagnostics = Analyze("""
+            using SharpEmu.HLE;
+
+            public static class Exports
+            {
+                [SysAbiExport(Nid = "Zxa0VhQVTsk", ExportName = "sceKernelWaitSema")]
+                [SysAbiExport(Nid = "not_a_nid")]
+                public static int Shared(CpuContext ctx) => 0;
+            }
+            """);
+
+        AssertSingle(diagnostics, "SHEM002");
+    }
+
     [Fact]
     public void MalformedNidIsReported()
     {

tests/SharpEmu.SourceGenerators.Tests/SysAbiExportGeneratorTests.cs

@@ -36,6 +36,11 @@ public sealed class SysAbiExportGeneratorTests
             // Guest string marshalling: the thunk reads the pointer before the handler.
             [SysAbiExport(Nid = "1G3lF1Gg1k8", ExportName = "sceKernelOpen")]
             public static int KernelOpen(CpuContext ctx, [GuestCString(4096)] string path, int flags) => 0;
+
+            // A single fail-closed handler may back a catalog of LLE-preferred exports.
+            [SysAbiExport(Nid = "5fbPUzoA2fM", ExportName = "sceLleFirst", Target = Generation.Gen5, LibraryName = "libSceLle", PreferLle = true)]
+            [SysAbiExport(Nid = "L9NfM+f4f1Y", ExportName = "sceLleSecond", Target = Generation.Gen5, LibraryName = "libSceLle", PreferLle = true)]
+            public static int LleFallback(CpuContext ctx) => -1;
         }
         """;
 
@@ -123,6 +128,22 @@ public sealed class SysAbiExportGeneratorTests
         Assert.Contains("(target & registrationGeneration) == 0", generated, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public void MultipleLlePreferredAttributesShareOneFailClosedHandler()
+    {
+        var (_, generated) = RoslynTestHost.RunGenerator(RoslynTestHost.Compile(HandlerSource));
+
+        Assert.Contains("\"5fbPUzoA2fM\"", generated, StringComparison.Ordinal);
+        Assert.Contains("\"L9NfM+f4f1Y\"", generated, StringComparison.Ordinal);
+        Assert.Equal(
+            2,
+            generated.Split("global::TestExports.SampleExports.LleFallback", StringSplitOptions.None).Length - 1);
+        Assert.Contains(
+            ", true, global::TestExports.SampleExports.LleFallback",
+            generated,
+            StringComparison.Ordinal);
+    }
+
     [Fact]
     public void AssemblyWithoutExportsEmitsNoRegistry()
     {