[llvm][TextAPI] Handle implicitly upgraded deployment versions

Sometimes the clang driver will receive a target triple where the
deployment version is too low to support the platform + arch. In those
cases, the compiler upgrades the final minOS which is what gets recorded
ultimately by the linker in LC_BUILD_VERSION. TextAPI should also reuse
this logic for capturing minOS in recorded TBDv5 files.

Reviewed By: ributzka

Differential Revision: https://reviews.llvm.org/D145690

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/TextAPI/Platform.cpp b/llvm/lib/TextAPI/Platform.cpp
index 673fcb7..a432462 100644
--- a/llvm/lib/TextAPI/Platform.cpp
+++ b/llvm/lib/TextAPI/Platform.cpp
@@ -132,5 +132,12 @@ std::string getOSAndEnvironmentName(PlatformType Platform,
   llvm_unreachable("Unknown llvm::MachO::PlatformType enum");
 }
 
+VersionTuple mapToSupportedOSVersion(const Triple &Triple) {
+  const VersionTuple MinSupportedOS = Triple.getMinimumSupportedOSVersion();
+  if (MinSupportedOS > Triple.getOSVersion())
+    return MinSupportedOS;
+  return Triple.getOSVersion();
+}
+
 } // end namespace MachO.
 } // end namespace llvm.