[ORC][MachO] Make BuildVersionOpts::fromTriple result optional, add test.

Only platform specific darwin OS values (e.g. macosx, ios, watchos, ...) can be
mapped to an LC_BUILD_VERSION platform. For all other values return an empty
optional to indicate that the load command can't be constructed.

Also fixes the simulator conditions to return the correct platform, and adds a
testcase.

Author: lhames

llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h

@@ -60,9 +60,9 @@ class MachOPlatform : public Platform {
 
     struct BuildVersionOpts {
 
-      // Derive platform from triple.
-      static BuildVersionOpts fromTriple(const Triple &TT, uint32_t MinOS,
-                                         uint32_t SDK);
+      // Derive platform from triple if possible.
+      static std::optional<BuildVersionOpts>
+      fromTriple(const Triple &TT, uint32_t MinOS, uint32_t SDK);
 
       uint32_t Platform; // Platform.
       uint32_t MinOS;    // X.Y.Z is encoded in nibbles xxxx.yy.zz

llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp

@@ -255,34 +255,33 @@ struct ObjCImageInfoFlags {
 namespace llvm {
 namespace orc {
 
-MachOPlatform::HeaderOptions::BuildVersionOpts
+std::optional<MachOPlatform::HeaderOptions::BuildVersionOpts>
 MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(const Triple &TT,
                                                            uint32_t MinOS,
                                                            uint32_t SDK) {
 
   uint32_t Platform;
   switch (TT.getOS()) {
   case Triple::IOS:
-    Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_IOS
-                                           : MachO::PLATFORM_IOSSIMULATOR;
+    Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_IOSSIMULATOR
+                                           : MachO::PLATFORM_IOS;
     break;
   case Triple::MacOSX:
     Platform = MachO::PLATFORM_MACOS;
     break;
   case Triple::TvOS:
-    Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_TVOS
-                                           : MachO::PLATFORM_TVOSSIMULATOR;
+    Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_TVOSSIMULATOR
+                                           : MachO::PLATFORM_TVOS;
     break;
   case Triple::WatchOS:
-    Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_WATCHOS
-                                           : MachO::PLATFORM_WATCHOSSIMULATOR;
+    Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_WATCHOSSIMULATOR
+                                           : MachO::PLATFORM_WATCHOS;
     break;
   default:
-    Platform = MachO::PLATFORM_UNKNOWN;
-    break;
+    return std::nullopt;
   }
 
-  return {Platform, MinOS, SDK};
+  return MachOPlatform::HeaderOptions::BuildVersionOpts{Platform, MinOS, SDK};
 }
 
 Expected<std::unique_ptr<MachOPlatform>> MachOPlatform::Create(

llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt

@@ -26,6 +26,7 @@ add_llvm_unittest(OrcJITTests
   JITTargetMachineBuilderTest.cpp
   LazyCallThroughAndReexportsTest.cpp
   LookupAndRecordAddrsTest.cpp
+  MachOPlatformTest.cpp
   MapperJITLinkMemoryManagerTest.cpp
   MemoryMapperTest.cpp
   ObjectFormatsTest.cpp

llvm/unittests/ExecutionEngine/Orc/MachOPlatformTest.cpp

@@ -0,0 +1,56 @@
+//===---------- MachOPlatformTest.cpp - MachPlatform API Tests ------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/Orc/MachOPlatform.h"
+#include "llvm/BinaryFormat/MachO.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace llvm::orc;
+
+TEST(MachOPlatformTests, BuildVersionOptsFromTriple) {
+
+  auto darwinOS = MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(
+      Triple("arm64-apple-darwin"), 0, 0);
+  EXPECT_FALSE(darwinOS);
+
+  auto macOS = MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(
+      Triple("arm64-apple-macosx"), 0, 0);
+  EXPECT_TRUE(macOS);
+  EXPECT_EQ(macOS->Platform, MachO::PLATFORM_MACOS);
+
+  auto iOS = MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(
+      Triple("arm64-apple-ios"), 0, 0);
+  EXPECT_TRUE(iOS);
+  EXPECT_EQ(iOS->Platform, MachO::PLATFORM_IOS);
+
+  auto iOSSim = MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(
+      Triple("arm64-apple-ios-simulator"), 0, 0);
+  EXPECT_TRUE(iOSSim);
+  EXPECT_EQ(iOSSim->Platform, MachO::PLATFORM_IOSSIMULATOR);
+
+  auto tvOS = MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(
+      Triple("arm64-apple-tvos"), 0, 0);
+  EXPECT_TRUE(tvOS);
+  EXPECT_EQ(tvOS->Platform, MachO::PLATFORM_TVOS);
+
+  auto tvOSSim = MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(
+      Triple("arm64-apple-tvos-simulator"), 0, 0);
+  EXPECT_TRUE(tvOSSim);
+  EXPECT_EQ(tvOSSim->Platform, MachO::PLATFORM_TVOSSIMULATOR);
+
+  auto watchOS = MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(
+      Triple("arm64-apple-watchos"), 0, 0);
+  EXPECT_TRUE(watchOS);
+  EXPECT_EQ(watchOS->Platform, MachO::PLATFORM_WATCHOS);
+
+  auto watchOSSim = MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(
+      Triple("arm64-apple-watchos-simulator"), 0, 0);
+  EXPECT_TRUE(watchOSSim);
+  EXPECT_EQ(watchOSSim->Platform, MachO::PLATFORM_WATCHOSSIMULATOR);
+}