[ORC][test] Add initial MachOPlatformTest

[keith]

Summary

From discussion on https://reviews.llvm.org/D130221

[dblaikie]

I'd probably skip this really low level/trivial test, and test just a bit higher level, as you've done in D139223

[keith]

2 thoughts:

1. having any tests for this class might be nice for encouraging others to add tests when they change this type, since this would already be setup
2. there are other callers to this function so regardless of what ORC keeps doing, this makes sure this functionality continues to work as expected for the other callers

but yea I don't feel strongly, so i can drop if you think that's the right move

[dblaikie]

In D139215#3967637, @keith wrote:

2 thoughts:

1. having any tests for this class might be nice for encouraging others to add tests when they change this type, since this would already be setup
2. there are other callers to this function so regardless of what ORC keeps doing, this makes sure this functionality continues to work as expected for the other callers

but yea I don't feel strongly, so i can drop if you think that's the right move

I can only find the one caller right now - and we tend to test fairly high level (relatively speaking) in LLVM - usually testing at the tool/program level, rather than down at the lowest API levels. (& if were strong unit test/API test adherents, I guess we'd have to test this function's behavior, then test that the callers call this function (with stubs/mocks/that sort of thing) - but that's not really the way LLVM goes for the most part, so testing a bit higher level, but still testing all the different sections here seems good to me)

(I assume the dynamic linker just has this as a hardcoded list somewhere too, @lhames Or should there be some special section flag or the like that is meant to help identify these/make it possible to add new ones witohut having to update linkers/loaders/etc)

llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt

add_llvm_unittest(OrcJITTests
   ExecutorAddressTest.cpp
   ExecutionSessionWrapperFunctionCallsTest.cpp
   EPCGenericJITLinkMemoryManagerTest.cpp
   EPCGenericMemoryAccessTest.cpp
   IndirectionUtilsTest.cpp
   JITTargetMachineBuilderTest.cpp
   LazyCallThroughAndReexportsTest.cpp
   LookupAndRecordAddrsTest.cpp
+  MachOPlatformTest.cpp
   MapperJITLinkMemoryManagerTest.cpp
   MemoryMapperTest.cpp
   ObjectLinkingLayerTest.cpp
   OrcCAPITest.cpp
   OrcTestCommon.cpp
   ResourceTrackerTest.cpp
   RTDyldObjectLinkingLayerTest.cpp
   SharedMemoryMapperTest.cpp

llvm/unittests/ExecutionEngine/Orc/MachOPlatformTest.cpp

+//===----------- MachOPlatformTest.cpp -- Tests for MachOPlatform ---------===//
+//
+// 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 "OrcTestCommon.h"
+
+#include "llvm/ExecutionEngine/Orc/MachOPlatform.h"
+
+using namespace llvm::orc;
+
+TEST(MachOPlatformTest, InitializerSectionTest) {
+  EXPECT_TRUE(MachOPlatform::isInitializerSection("__DATA", "__mod_init_func"));
+  EXPECT_TRUE(
+      MachOPlatform::isInitializerSection("__DATA", "__objc_classlist"));
+  EXPECT_TRUE(MachOPlatform::isInitializerSection("__DATA", "__objc_selrefs"));
+  EXPECT_TRUE(MachOPlatform::isInitializerSection("__TEXT", "__swift5_proto"));
+  EXPECT_TRUE(MachOPlatform::isInitializerSection("__TEXT", "__swift5_protos"));
+  EXPECT_TRUE(MachOPlatform::isInitializerSection("__TEXT", "__swift5_types"));
+
+  EXPECT_FALSE(MachOPlatform::isInitializerSection("__TEXT", "__text"));
+}