[TBDGen] Swift ABI Version can be a constant, not a magic number.

Author: huonw

include/swift/TBDGen/TBDGen.h

@@ -23,6 +23,9 @@ namespace swift {
 class FileUnit;
 class ModuleDecl;
 
+/// \brief The current ABI version of Swift, as tapi labels it.
+const uint8_t TAPI_SWIFT_ABI_VERSION = 5;
+
 /// \brief Options for controlling the exact set of symbols included in the TBD
 /// output.
 struct TBDGenOptions {

lib/TBDGen/TBDGen.cpp

@@ -419,8 +419,7 @@ static void enumeratePublicSymbolsAndWrite(ModuleDecl *M, FileUnit *singleFile,
   file.setInstallName(opts.InstallName);
   // FIXME: proper version
   file.setCurrentVersion(tapi::internal::PackedVersion(1, 0, 0));
-  // FIXME: pull this out of moduleformat?
-  file.setSwiftABIVersion(5);
+  file.setSwiftABIVersion(TAPI_SWIFT_ABI_VERSION);
   file.setPlatform(tapi::internal::mapToSinglePlatform(target));
   auto arch = tapi::internal::getArchType(target.getArchName());
   file.setArch(arch);