Add checking of differing swift versions in input files.

Swift versions are part of the objc image info section, and must match
for all files linked which actually have an image info section

llvm-svn: 257964

3 files changed, 18 insertions, 0 deletions

diff --git a/lld/lib/ReaderWriter/MachO/File.h b/lld/lib/ReaderWriter/MachO/File.h
index 24e042ed3b5..c95b2da989a 100644
--- a/lld/lib/ReaderWriter/MachO/File.h
+++ b/lld/lib/ReaderWriter/MachO/File.h
@@ -194,6 +194,9 @@ public:
   MachOLinkingContext::OS OS() const { return _os; }
   void setOS(MachOLinkingContext::OS os) { _os = os; }
 
+  uint32_t swiftVersion() const { return _swiftVersion; }
+  void setSwiftVersion(uint32_t v) { _swiftVersion = v; }
+
   /// Methods for support type inquiry through isa, cast, and dyn_cast:
   static inline bool classof(const File *F) {
     return F->kind() == File::kindMachObject;
@@ -234,6 +237,7 @@ private:
   NameToAtom                     _undefAtoms;
   MachOLinkingContext::Arch      _arch = MachOLinkingContext::arch_unknown;
   MachOLinkingContext::OS        _os = MachOLinkingContext::OS::unknown;
+  uint32_t                       _swiftVersion = 0;
 };
 
 class MachODylibFile : public SharedLibraryFile {
diff --git a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
index c129e9e529c..6987f7afb06 100644
--- a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
@@ -145,6 +145,7 @@ MachOLinkingContext::MachOLinkingContext()
       _doNothing(false), _pie(false), _arch(arch_unknown), _os(OS::macOSX),
       _osMinVersion(0), _pageZeroSize(0), _pageSize(4096), _baseAddress(0),
       _stackSize(0), _compatibilityVersion(0), _currentVersion(0),
+      _swiftVersion(0),
       _flatNamespace(false), _undefinedMode(UndefinedMode::error),
       _deadStrippableDylib(false), _printAtoms(false), _testingFileUsage(false),
       _keepPrivateExterns(false), _demangle(false), _archHandler(nullptr),
@@ -1015,6 +1016,16 @@ std::error_code MachOLinkingContext::handleLoadedFile(File &file) {
     return make_dynamic_error_code(file.path() +
               Twine(" cannot be linked due to incompatible operating systems"));
   }
+
+  // Check that the swift version of the context matches that of the file.
+  // Also set the swift version of the context if it didn't have one.
+  if (!_swiftVersion) {
+    _swiftVersion = machoFile->swiftVersion();
+  } else if (machoFile->swiftVersion() &&
+             machoFile->swiftVersion() != _swiftVersion) {
+    // Swift versions are different.
+    return make_dynamic_error_code("different swift versions");
+  }
   return std::error_code();
 }
 
diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
index 770b58b2270..78c930bac0f 100644
--- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
@@ -911,6 +911,9 @@ std::error_code parseObjCImageInfo(const NormalizedFile &normalizedFile,
                                    " in file " + file.path() +
                                    " should have version=0");
 
+  uint32_t flags = read32(content.data() + 4, isBig);
+  file.setSwiftVersion((flags >> 8) & 0xFF);
+
   return std::error_code();
 }