Cache the objc image info constraints in file.

Image info flags describe the objc constraint which is GC/retain/release/etc.

These need to be parsed and stored in the file so that we can do error checking.

That will come in a later commit.

llvm-svn: 258160

4 files changed, 34 insertions, 11 deletions

diff --git a/lld/include/lld/ReaderWriter/MachOLinkingContext.h b/lld/include/lld/ReaderWriter/MachOLinkingContext.h
index 671f4515e77..32a03fb790c 100644
--- a/lld/include/lld/ReaderWriter/MachOLinkingContext.h
+++ b/lld/include/lld/ReaderWriter/MachOLinkingContext.h
@@ -71,6 +71,16 @@ public:
     dynamicLookup
   };
 
+  enum ObjCConstraint {
+    objc_unknown = 0,
+    objc_supports_gc = 2,
+    objc_gc_only = 4,
+    // Image optimized by dyld = 8
+    // GC compaction = 16
+    objc_retainReleaseForSimulator = 32,
+    objc_retainRelease
+  };
+
   /// Initializes the context to sane default values given the specified output
   /// file type, arch, os, and minimum os version.  This should be called before
   /// other setXXX() methods.
@@ -143,6 +153,9 @@ public:
   uint64_t baseAddress() const { return _baseAddress; }
   void setBaseAddress(uint64_t baseAddress) { _baseAddress = baseAddress; }
 
+  ObjCConstraint objcConstraint() const { return _objcConstraint; }
+  void setObjcConstraint(ObjCConstraint v) { _objcConstraint = v; }
+
   /// \brief Checks whether a given path on the filesystem exists.
   ///
   /// When running in -test_file_usage mode, this method consults an
@@ -398,6 +411,7 @@ private:
   uint64_t _stackSize;
   uint32_t _compatibilityVersion;
   uint32_t _currentVersion;
+  ObjCConstraint _objcConstraint;
   uint32_t _swiftVersion;
   StringRef _installName;
   StringRefVector _rpaths;
diff --git a/lld/lib/ReaderWriter/MachO/File.h b/lld/lib/ReaderWriter/MachO/File.h
index 7b28590d3ca..1ba71dc67dc 100644
--- a/lld/lib/ReaderWriter/MachO/File.h
+++ b/lld/lib/ReaderWriter/MachO/File.h
@@ -194,6 +194,13 @@ public:
   MachOLinkingContext::OS OS() const { return _os; }
   void setOS(MachOLinkingContext::OS os) { _os = os; }
 
+  MachOLinkingContext::ObjCConstraint objcConstraint() const {
+    return _objcConstraint;
+  }
+  void setObjcConstraint(MachOLinkingContext::ObjCConstraint v) {
+    _objcConstraint = v;
+  }
+
   uint32_t swiftVersion() const { return _swiftVersion; }
   void setSwiftVersion(uint32_t v) { _swiftVersion = v; }
 
@@ -242,6 +249,8 @@ private:
   NameToAtom                     _undefAtoms;
   MachOLinkingContext::Arch      _arch = MachOLinkingContext::arch_unknown;
   MachOLinkingContext::OS        _os = MachOLinkingContext::OS::unknown;
+  MachOLinkingContext::ObjCConstraint _objcConstraint =
+      MachOLinkingContext::objc_unknown;
   uint32_t                       _swiftVersion = 0;
   normalized::FileFlags          _flags;
 };
diff --git a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
index 6987f7afb06..5fcc259a498 100644
--- a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
@@ -145,11 +145,10 @@ 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),
-      _exportMode(ExportMode::globals),
+      _objcConstraint(objc_unknown), _swiftVersion(0), _flatNamespace(false),
+      _undefinedMode(UndefinedMode::error), _deadStrippableDylib(false),
+      _printAtoms(false), _testingFileUsage(false), _keepPrivateExterns(false),
+      _demangle(false), _archHandler(nullptr), _exportMode(ExportMode::globals),
       _debugInfoMode(DebugInfoMode::addDebugMap), _orderFileEntries(0),
       _flatNamespaceFile(nullptr) {}
 
diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
index 342cce4cbcf..44e22ab6491 100644
--- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
@@ -892,11 +892,6 @@ std::error_code parseObjCImageInfo(const NormalizedFile &normalizedFile,
   //		uint32_t	version;	// initially 0
   //		uint32_t	flags;
   //	};
-  enum {
-    OBJC_IMAGE_SUPPORTS_GC=2,
-    OBJC_IMAGE_GC_ONLY=4,
-    OBJC_IMAGE_IS_SIMULATED=32,
-  };
 
   ArrayRef<uint8_t> content = imageInfoSection->content;
   if (content.size() != 8)
@@ -914,12 +909,18 @@ std::error_code parseObjCImageInfo(const NormalizedFile &normalizedFile,
                                    " should have version=0");
 
   uint32_t flags = read32(content.data() + 4, isBig);
-  if (flags & (OBJC_IMAGE_SUPPORTS_GC|OBJC_IMAGE_GC_ONLY))
+  if (flags & (MachOLinkingContext::objc_supports_gc |
+               MachOLinkingContext::objc_gc_only))
     return make_dynamic_error_code(imageInfoSection->segmentName + "/" +
                                    imageInfoSection->sectionName +
                                    " in file " + file.path() +
                                    " uses GC.  This is not supported");
 
+  if (flags & MachOLinkingContext::objc_retainReleaseForSimulator)
+    file.setObjcConstraint(MachOLinkingContext::objc_retainReleaseForSimulator);
+  else
+    file.setObjcConstraint(MachOLinkingContext::objc_retainRelease);
+
   file.setSwiftVersion((flags >> 8) & 0xFF);
 
   return std::error_code();