[llvm][TextAPI/MachO] Emit swift ABI version as an un integer in TBD_V4

[JDevlieghere]

Summary

TBD_V4 requires the swift ABI version to be an integer, however we were unconditionally emitting it as a float for versions 4 and below.

[merge_guards_bot]

Unit tests: fail. 62152 tests passed, 5 failed and 811 were skipped.

failed: libc++.std/language_support/cmp/cmp_partialord/partialord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongeq/cmp.strongeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongord/strongord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakeq/cmp.weakeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakord/weakord.pass.cpp

clang-tidy: fail. clang-tidy found 0 errors and 2 warnings. 0 of them are added as review comments below (why?).

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[JDevlieghere]

Talked to Cyndy offline and this is not the right solution.

llvm/lib/TextAPI/MachO/TextStubCommon.cpp

StringRef ScalarTraits<PackedVersion>::input(StringRef Scalar, void *,
   if (!Value.parse32(Scalar))
     return "invalid packed version string.";
   return {};
 }
 QuotingType ScalarTraits<PackedVersion>::mustQuote(StringRef) {
   return QuotingType::None;
 }
 
-void ScalarTraits<SwiftVersion>::output(const SwiftVersion &Value, void *,
+void ScalarTraits<SwiftVersion>::output(const SwiftVersion &Value, void *IO,
                                         raw_ostream &OS) {
+  const auto *Ctx = reinterpret_cast<TextAPIContext *>(IO);
+  if (Ctx->FileKind == FileType::TBD_V4) {
+    OS << (unsigned)Value;
+    return;
+  }
+
   switch (Value) {
   case 1:
     OS << "1.0";
     break;
   case 2:
     OS << "1.1";
     break;
   case 3:

llvm/unittests/TextAPI/TextStubV4Tests.cpp

static const char tbd_swift_1[] = "--- !tapi-tbd\n"
                                     "...\n";
 
   auto Result = TextAPIReader::get(MemoryBufferRef(tbd_swift_1, "Test.tbd"));
   EXPECT_TRUE(!!Result);
   auto File = std::move(Result.get());
   EXPECT_EQ(FileType::TBD_V4, File->getFileType());
   EXPECT_EQ(1U, File->getSwiftABIVersion());
 
-  // No writer test because we emit "swift-abi-version:1.0".
+  SmallString<4096> Buffer;
+  raw_svector_ostream OS(Buffer);
+  auto WriteResult = TextAPIWriter::writeToStream(OS, *File);
+  EXPECT_TRUE(!WriteResult);
+  EXPECT_EQ(stripWhitespace(tbd_swift_1), stripWhitespace(Buffer.c_str()));
 }
 
 TEST(TBDv4, Swift_2) {
   static const char tbd_v4_swift_2[] = "--- !tapi-tbd\n"
                                        "tbd-version: 4\n"
                                        "targets: [  x86_64-macos ]\n"
                                        "install-name: Test.dylib\n"
                                        "swift-abi-version: 2\n"
                                        "...\n";
 
   auto Result = TextAPIReader::get(MemoryBufferRef(tbd_v4_swift_2, "Test.tbd"));
   EXPECT_TRUE(!!Result);
   auto File = std::move(Result.get());
   EXPECT_EQ(FileType::TBD_V4, File->getFileType());
   EXPECT_EQ(2U, File->getSwiftABIVersion());
 
-  // No writer test because we emit "swift-abi-version:2.0".
+  SmallString<4096> Buffer;
+  raw_svector_ostream OS(Buffer);
+  auto WriteResult = TextAPIWriter::writeToStream(OS, *File);
+  EXPECT_TRUE(!WriteResult);
+  EXPECT_EQ(stripWhitespace(tbd_v4_swift_2), stripWhitespace(Buffer.c_str()));
 }
 
 TEST(TBDv4, Swift_5) {
   static const char tbd_swift_5[] = "--- !tapi-tbd\n"
                                     "tbd-version: 4\n"
                                     "targets: [  x86_64-macos ]\n"
                                     "install-name: Test.dylib\n"
                                     "swift-abi-version: 5\n"