[macho] emit LC_BUILD_VERSION load command for supported OSes and platforms

[arphaman]

Summary

This change lets LLVM use the LC_BUILD_VERSION command when building for macOS 10.14, iOS 12, tvOS 12, and watchOS 5. Additionally, this change ensures that new platforms like Apple Silicon macOS / Mac Catalyst, and simulators running on Apple Silicon alway use LC_BUILD_VERSION with the OS version set to the minimum supported OS version if the deployment target version is older.

[steven_wu]

LGTM

llvm/lib/MC/MCStreamer.cpp

MCSymbol *MCStreamer::endSection(MCSection *Section) {
   if (Sym->isInSection())
     return Sym;
 
   SwitchSection(Section);
   emitLabel(Sym);
   return Sym;
 }
 
+static VersionTuple
+targetVersionOrMinimumSupportedOSVersion(const Triple &Target,
+                                         VersionTuple TargetVersion) {
+  VersionTuple Min = Target.getMinimumSupportedOSVersion();
+  return !Min.empty() && Min > TargetVersion ? Min : TargetVersion;
+}
+
+static MCVersionMinType
+getMachoVersionMinLoadCommandType(const Triple &Target) {
+  assert(Target.isOSDarwin() && "expected a darwin OS");
+  switch (Target.getOS()) {
+  case Triple::MacOSX:
+  case Triple::Darwin:
+    return MCVM_OSXVersionMin;
+  case Triple::IOS:
+    assert(!Target.isMacCatalystEnvironment() &&
+           "mac Catalyst should use LC_BUILD_VERSION");
+    return MCVM_IOSVersionMin;
+  case Triple::TvOS:
+    return MCVM_TvOSVersionMin;
+  case Triple::WatchOS:
+    return MCVM_WatchOSVersionMin;
+  default:
+    break;
+  }
+  llvm_unreachable("unexpected OS type");
+}
+
+static VersionTuple getMachoBuildVersionSupportedOS(const Triple &Target) {
+  assert(Target.isOSDarwin() && "expected a darwin OS");
+  switch (Target.getOS()) {
+  case Triple::MacOSX:
+  case Triple::Darwin:
+    return VersionTuple(10, 14);
+  case Triple::IOS:
+    // Mac Catalyst always uses the build version load command.
+    if (Target.isMacCatalystEnvironment())
+      return VersionTuple();
+    LLVM_FALLTHROUGH;
+  case Triple::TvOS:
+    return VersionTuple(12);
+  case Triple::WatchOS:
+    return VersionTuple(5);
+  default:
+    break;
+  }
+  llvm_unreachable("unexpected OS type");
+}
+
+static MachO::PlatformType
+getMachoBuildVersionPlatformType(const Triple &Target) {
+  assert(Target.isOSDarwin() && "expected a darwin OS");
+  switch (Target.getOS()) {
+  case Triple::MacOSX:
+  case Triple::Darwin:
+    return MachO::PLATFORM_MACOS;
+  case Triple::IOS:
+    if (Target.isMacCatalystEnvironment())
+      return MachO::PLATFORM_MACCATALYST;
+    return Target.isSimulatorEnvironment() ? MachO::PLATFORM_IOSSIMULATOR
+                                           : MachO::PLATFORM_IOS;
+  case Triple::TvOS:
+    return Target.isSimulatorEnvironment() ? MachO::PLATFORM_TVOSSIMULATOR
+                                           : MachO::PLATFORM_TVOS;
+  case Triple::WatchOS:
+    return Target.isSimulatorEnvironment() ? MachO::PLATFORM_WATCHOSSIMULATOR
+                                           : MachO::PLATFORM_WATCHOS;
+  default:
+    break;
+  }
+  llvm_unreachable("unexpected OS type");
+}
+
 void MCStreamer::emitVersionForTarget(const Triple &Target,
                                       const VersionTuple &SDKVersion) {
   if (!Target.isOSBinFormatMachO() || !Target.isOSDarwin())
     return;
   // Do we even know the version?
   if (Target.getOSMajorVersion() == 0)
     return;
 
-  unsigned Major;
-  unsigned Minor;
-  unsigned Update;
-  if (Target.isMacCatalystEnvironment()) {
-    // Mac Catalyst always uses the build version load command.
+  unsigned Major = 0;
+  unsigned Minor = 0;
+  unsigned Update = 0;
+  switch (Target.getOS()) {
+  case Triple::MacOSX:
+  case Triple::Darwin:
+    Target.getMacOSXVersion(Major, Minor, Update);
+    break;
+  case Triple::IOS:
+  case Triple::TvOS:
     Target.getiOSVersion(Major, Minor, Update);
-    assert(Major && "A non-zero major version is expected");
-    emitBuildVersion(MachO::PLATFORM_MACCATALYST, Major, Minor, Update,
-                     SDKVersion);
-    return;
-  }
-
-  MCVersionMinType VersionType;
-  if (Target.isWatchOS()) {
-    VersionType = MCVM_WatchOSVersionMin;
+    break;
+  case Triple::WatchOS:
     Target.getWatchOSVersion(Major, Minor, Update);
-  } else if (Target.isTvOS()) {
-    VersionType = MCVM_TvOSVersionMin;
-    Target.getiOSVersion(Major, Minor, Update);
-  } else if (Target.isMacOSX()) {
-    VersionType = MCVM_OSXVersionMin;
-    if (!Target.getMacOSXVersion(Major, Minor, Update))
-      Major = 0;
-  } else {
-    VersionType = MCVM_IOSVersionMin;
-    Target.getiOSVersion(Major, Minor, Update);
+    break;
+  default:
+    llvm_unreachable("unexpected OS type");
   }
-  if (Major != 0)
-    emitVersionMin(VersionType, Major, Minor, Update, SDKVersion);
+  assert(Major != 0 && "A non-zero major version is expected");
+  auto LinkedTargetVersion = targetVersionOrMinimumSupportedOSVersion(
+      Target, VersionTuple(Major, Minor, Update));
+  auto BuildVersionOSVersion = getMachoBuildVersionSupportedOS(Target);
+  if (BuildVersionOSVersion.empty() ||
+      LinkedTargetVersion >= BuildVersionOSVersion)
+    return emitBuildVersion(getMachoBuildVersionPlatformType(Target),
+                            LinkedTargetVersion.getMajor(),
+                            *LinkedTargetVersion.getMinor(),
+                            *LinkedTargetVersion.getSubminor(), SDKVersion);
+
+  emitVersionMin(getMachoVersionMinLoadCommandType(Target),
+                 LinkedTargetVersion.getMajor(),
+                 *LinkedTargetVersion.getMinor(),
+                 *LinkedTargetVersion.getSubminor(), SDKVersion);
 }

llvm/lib/Support/Triple.cpp

if (Major == 10) {
     assert(Major >= 11 && "Unexpected major version");
     return isOSVersionLT(Major - 11 + 20, Minor, Micro);
   }
 }
 
 VersionTuple Triple::getMinimumSupportedOSVersion() const {
   if (getVendor() != Triple::Apple || getArch() != Triple::aarch64)
     return VersionTuple();
-  /// ARM64 slice is supported starting from macOS 11.0+.
-  if (getOS() == Triple::MacOSX)
+  switch (getOS()) {
+  case Triple::MacOSX:
+    // ARM64 slice is supported starting from macOS 11.0+.
     return VersionTuple(11, 0, 0);
-  if (getOS() == Triple::IOS && isMacCatalystEnvironment())
+  case Triple::IOS:
+    // ARM64 slice is supported starting from Mac Catalyst 14 (macOS 11).
+    // ARM64 simulators are supported for iOS 14+.
+    if (isMacCatalystEnvironment() || isSimulatorEnvironment())
       return VersionTuple(14, 0, 0);
+    break;
+  case Triple::TvOS:
+    // ARM64 simulators are supported for tvOS 14+.
+    if (isSimulatorEnvironment())
+      return VersionTuple(14, 0, 0);
+    break;
+  case Triple::WatchOS:
+    // ARM64 simulators are supported for watchOS 7+.
+    if (isSimulatorEnvironment())
+      return VersionTuple(7, 0, 0);
+    break;
+  default:
+    break;
+  }
   return VersionTuple();
 }
 
 StringRef Triple::getARMCPUForArch(StringRef MArch) const {
   if (MArch.empty())
     MArch = getArchName();
   MArch = ARM::getCanonicalArchName(MArch);
 

llvm/test/MC/MachO/darwin-version-min-load-command.s

 // RUN: llvm-mc -triple x86_64-apple-macosx10.10.0 %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s
 // RUN: llvm-mc -triple x86_64-apple-ios8.0.0 %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-IOS
 // RUN: llvm-mc -triple x86_64-apple-darwin %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-DARWIN
 // RUN: llvm-mc -triple x86_64-apple-ios13.0-macabi %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-MACCATALYST
 
+// RUN: llvm-mc -triple x86_64-apple-macos10.14 %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-MACOS
+// RUN: llvm-mc -triple x86_64-apple-ios12 %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-IOS
+// RUN: llvm-mc -triple x86_64-apple-tvos12 %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-TVOS
+// RUN: llvm-mc -triple x86_64-apple-watchos5 %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-WATCHOS
+// RUN: llvm-mc -triple x86_64-apple-ios12-simulator %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-IOSSIM
+// RUN: llvm-mc -triple x86_64-apple-tvos12-simulator %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-TVOSSIM
+// RUN: llvm-mc -triple x86_64-apple-watchos5-simulator %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-WATCHOSSIM
+
+// RUN: llvm-mc -triple arm64-apple-macos10.10.2 %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-MACOS-ARM64
+// RUN: llvm-mc -triple arm64-apple-macos11 %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-MACOS-ARM64
+// RUN: llvm-mc -triple arm64-apple-macos11.1 %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-MACOS-ARM64_1
+// RUN: llvm-mc -triple arm64-apple-ios13.0-macabi %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-MACCATALYST-ARM64
+// RUN: llvm-mc -triple arm64-apple-ios14.1-macabi %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-MACCATALYST-ARM64_1
+
+// RUN: llvm-mc -triple arm64-apple-ios10-simulator %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-IOSSIM2
+// RUN: llvm-mc -triple arm64-apple-ios13-simulator %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-IOSSIM2
+// RUN: llvm-mc -triple arm64-apple-ios14-simulator %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-IOSSIM2
+// RUN: llvm-mc -triple arm64-apple-ios14.1-simulator %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-IOSSIM3
+// RUN: llvm-mc -triple arm64-apple-tvos10-simulator %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-TVOSSIM2
+// RUN: llvm-mc -triple arm64-apple-watchos3-simulator %s -filetype=obj -o - | llvm-objdump --macho --private-headers - | FileCheck %s --check-prefix=CHECK-BUILD-WATCHOSSIM2
+
+
 // Test version-min load command should be inferred from triple and should always be generated on Darwin
 // CHECK: Load command
 // CHECK:       cmd LC_VERSION_MIN_MACOSX
 // CHECK:   cmdsize 16
 // CHECK:   version 10.10
 
 // CHECK-IOS: Load command
 // CHECK-IOS:       cmd LC_VERSION_MIN_IPHONEOS

 // CHECK-BRIDGEOS-NEXT:    ntools 0
 
 // CHECK-MACCATALYST:           cmd LC_BUILD_VERSION
 // CHECK-MACCATALYST-NEXT:  cmdsize 24
 // CHECK-MACCATALYST-NEXT: platform macCatalyst
 // CHECK-MACCATALYST-NEXT:      sdk n/a
 // CHECK-MACCATALYST-NEXT:    minos 13.0
 // CHECK-MACCATALYST-NEXT:   ntools 0
+
+// CHECK-BUILD-MACOS:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-MACOS-NEXT:  cmdsize 24
+// CHECK-BUILD-MACOS-NEXT: platform macos
+// CHECK-BUILD-MACOS-NEXT:      sdk n/a
+// CHECK-BUILD-MACOS-NEXT:    minos 10.14
+// CHECK-BUILD-MACOS-NEXT:   ntools 0
+// CHECK-BUILD-MACOS-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-IOS:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-IOS-NEXT:  cmdsize 24
+// CHECK-BUILD-IOS-NEXT: platform ios
+// CHECK-BUILD-IOS-NEXT:      sdk n/a
+// CHECK-BUILD-IOS-NEXT:    minos 12.0
+// CHECK-BUILD-IOS-NEXT:   ntools 0
+// CHECK-BUILD-IOS-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-TVOS:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-TVOS-NEXT:  cmdsize 24
+// CHECK-BUILD-TVOS-NEXT: platform tvos
+// CHECK-BUILD-TVOS-NEXT:      sdk n/a
+// CHECK-BUILD-TVOS-NEXT:    minos 12.0
+// CHECK-BUILD-TVOS-NEXT:   ntools 0
+// CHECK-BUILD-TVOS-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-WATCHOS:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-WATCHOS-NEXT:  cmdsize 24
+// CHECK-BUILD-WATCHOS-NEXT: platform watchos
+// CHECK-BUILD-WATCHOS-NEXT:      sdk n/a
+// CHECK-BUILD-WATCHOS-NEXT:    minos 5.0
+// CHECK-BUILD-WATCHOS-NEXT:   ntools 0
+// CHECK-BUILD-WATCHOS-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-IOSSIM:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-IOSSIM-NEXT:  cmdsize 24
+// CHECK-BUILD-IOSSIM-NEXT: platform iossim
+// CHECK-BUILD-IOSSIM-NEXT:      sdk n/a
+// CHECK-BUILD-IOSSIM-NEXT:    minos 12.0
+// CHECK-BUILD-IOSSIM-NEXT:   ntools 0
+// CHECK-BUILD-IOSSIM-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-IOSSIM2:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-IOSSIM2-NEXT:  cmdsize 24
+// CHECK-BUILD-IOSSIM2-NEXT: platform iossim
+// CHECK-BUILD-IOSSIM2-NEXT:      sdk n/a
+// CHECK-BUILD-IOSSIM2-NEXT:    minos 14.0
+// CHECK-BUILD-IOSSIM2-NEXT:   ntools 0
+// CHECK-BUILD-IOSSIM2-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-IOSSIM3:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-IOSSIM3-NEXT:  cmdsize 24
+// CHECK-BUILD-IOSSIM3-NEXT: platform iossim
+// CHECK-BUILD-IOSSIM3-NEXT:      sdk n/a
+// CHECK-BUILD-IOSSIM3-NEXT:    minos 14.1
+// CHECK-BUILD-IOSSIM3-NEXT:   ntools 0
+// CHECK-BUILD-IOSSIM3-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-TVOSSIM:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-TVOSSIM-NEXT:  cmdsize 24
+// CHECK-BUILD-TVOSSIM-NEXT: platform tvossim
+// CHECK-BUILD-TVOSSIM-NEXT:      sdk n/a
+// CHECK-BUILD-TVOSSIM-NEXT:    minos 12.0
+// CHECK-BUILD-TVOSSIM-NEXT:   ntools 0
+// CHECK-BUILD-TVOSSIM-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-TVOSSIM2:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-TVOSSIM2-NEXT:  cmdsize 24
+// CHECK-BUILD-TVOSSIM2-NEXT: platform tvossim
+// CHECK-BUILD-TVOSSIM2-NEXT:      sdk n/a
+// CHECK-BUILD-TVOSSIM2-NEXT:    minos 14.0
+// CHECK-BUILD-TVOSSIM2-NEXT:   ntools 0
+// CHECK-BUILD-TVOSSIM2-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-WATCHOSSIM:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-WATCHOSSIM-NEXT:  cmdsize 24
+// CHECK-BUILD-WATCHOSSIM-NEXT: platform watchossim
+// CHECK-BUILD-WATCHOSSIM-NEXT:      sdk n/a
+// CHECK-BUILD-WATCHOSSIM-NEXT:    minos 5.0
+// CHECK-BUILD-WATCHOSSIM-NEXT:   ntools 0
+// CHECK-BUILD-WATCHOSSIM-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-WATCHOSSIM2:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-WATCHOSSIM2-NEXT:  cmdsize 24
+// CHECK-BUILD-WATCHOSSIM2-NEXT: platform watchossim
+// CHECK-BUILD-WATCHOSSIM2-NEXT:      sdk n/a
+// CHECK-BUILD-WATCHOSSIM2-NEXT:    minos 7.0
+// CHECK-BUILD-WATCHOSSIM2-NEXT:   ntools 0
+// CHECK-BUILD-WATCHOSSIM2-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-MACOS-ARM64:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-MACOS-ARM64-NEXT:  cmdsize 24
+// CHECK-BUILD-MACOS-ARM64-NEXT: platform macos
+// CHECK-BUILD-MACOS-ARM64-NEXT:      sdk n/a
+// CHECK-BUILD-MACOS-ARM64-NEXT:    minos 11.0
+// CHECK-BUILD-MACOS-ARM64-NEXT:   ntools 0
+// CHECK-BUILD-MACOS-ARM64-NOT: LC_VERSION_MIN
+
+// CHECK-BUILD-MACOS-ARM64_1:           cmd LC_BUILD_VERSION
+// CHECK-BUILD-MACOS-ARM64_1-NEXT:  cmdsize 24
+// CHECK-BUILD-MACOS-ARM64_1-NEXT: platform macos
+// CHECK-BUILD-MACOS-ARM64_1-NEXT:      sdk n/a
+// CHECK-BUILD-MACOS-ARM64_1-NEXT:    minos 11.1
+// CHECK-BUILD-MACOS-ARM64_1-NEXT:   ntools 0
+
+// CHECK-MACCATALYST-ARM64:           cmd LC_BUILD_VERSION
+// CHECK-MACCATALYST-ARM64-NEXT:  cmdsize 24
+// CHECK-MACCATALYST-ARM64-NEXT: platform macCatalyst
+// CHECK-MACCATALYST-ARM64-NEXT:      sdk n/a
+// CHECK-MACCATALYST-ARM64-NEXT:    minos 14.0
+// CHECK-MACCATALYST-ARM64-NEXT:   ntools 0
+
+// CHECK-MACCATALYST-ARM64_1:           cmd LC_BUILD_VERSION
+// CHECK-MACCATALYST-ARM64_1-NEXT:  cmdsize 24
+// CHECK-MACCATALYST-ARM64_1-NEXT: platform macCatalyst
+// CHECK-MACCATALYST-ARM64_1-NEXT:      sdk n/a
+// CHECK-MACCATALYST-ARM64_1-NEXT:    minos 14.1
+// CHECK-MACCATALYST-ARM64_1-NEXT:   ntools 0