Use __nl_symbol_ptr instead of __got in the stubs pass on x86 archs.

The non lazy atoms generated in the stubs pass use an image cache to
hold all of the pointers.  On arm archs, this is the __got section,
but on x86 archs it should be __nl_symbol_ptr.

rdar://problem/24572729

llvm-svn: 260271

lld/include/lld/Core/DefinedAtom.h

@@ -129,6 +129,7 @@ public:
     typeObjC1Class,         // ObjC1 class [Darwin]
     typeLazyPointer,        // pointer through which a stub jumps
     typeLazyDylibPointer,   // pointer through which a stub jumps [Darwin]
+    typeNonLazyPointer,     // pointer to external symbol
     typeCFString,           // NS/CFString object [Darwin]
     typeGOT,                // pointer to external symbol
     typeInitializerPtr,     // pointer to initializer function

lld/lib/Core/DefinedAtom.cpp

@@ -54,6 +54,7 @@ DefinedAtom::ContentPermissions DefinedAtom::permissions(ContentType type) {
   case typeObjC1Class:
   case typeLazyPointer:
   case typeLazyDylibPointer:
+  case typeNonLazyPointer:
   case typeThunkTLV:
   case typeRWNote:
     return permRW_;

lld/lib/ReaderWriter/MachO/ArchHandler.h

@@ -255,6 +255,8 @@ public:
     ReferenceInfo   stubHelperReferenceToImm;
     ReferenceInfo   stubHelperReferenceToHelperCommon;
 
+    DefinedAtom::ContentType stubHelperImageCacheContentType;
+
     uint32_t        stubHelperCommonSize;
     uint8_t         stubHelperCommonAlignment;
     uint8_t         stubHelperCommonBytes[36];

lld/lib/ReaderWriter/MachO/ArchHandler_arm.cpp

@@ -260,6 +260,9 @@ const ArchHandler::StubInfo ArchHandler_arm::_sStubInfoArmPIC = {
   { Reference::KindArch::ARM, lazyImmediateLocation, 8, 0 },
   { Reference::KindArch::ARM, arm_b24, 4, 0 },
 
+  // Stub helper image cache content type
+  DefinedAtom::typeGOT,
+
   // Stub Helper-Common size and code
   36,
   // Stub helper alignment

lld/lib/ReaderWriter/MachO/ArchHandler_arm64.cpp

@@ -283,6 +283,9 @@ const ArchHandler::StubInfo ArchHandler_arm64::_sStubInfo = {
   { Reference::KindArch::AArch64, lazyImmediateLocation, 8, 0 },
   { Reference::KindArch::AArch64, branch26, 4, 0 },
 
+  // Stub helper image cache content type
+  DefinedAtom::typeGOT,
+
   // Stub Helper-Common size and code
   24,
   // Stub helper alignment

lld/lib/ReaderWriter/MachO/ArchHandler_x86.cpp

@@ -216,6 +216,9 @@ const ArchHandler::StubInfo ArchHandler_x86::_sStubInfo = {
   { Reference::KindArch::x86, lazyImmediateLocation, 1, 0 },
   { Reference::KindArch::x86, branch32, 6, 0 },
 
+  // Stub helper image cache content type
+  DefinedAtom::typeNonLazyPointer,
+
   // Stub Helper-Common size and code
   12,
   // Stub helper alignment

lld/lib/ReaderWriter/MachO/ArchHandler_x86_64.cpp

@@ -284,6 +284,9 @@ const ArchHandler::StubInfo ArchHandler_x86_64::_sStubInfo = {
   { Reference::KindArch::x86_64, lazyImmediateLocation, 1, 0 },
   { Reference::KindArch::x86_64, branch32, 6, 0 },
 
+  // Stub helper image cache content type
+  DefinedAtom::typeNonLazyPointer,
+
   // Stub Helper-Common size and code
   16,
   // Stub helper alignment

lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp

@@ -283,6 +283,8 @@ const MachOFinalSectionFromAtomType sectsToAtomType[] = {
                                                           typeTerminatorPtr),
   ENTRY("__DATA", "__got",            S_NON_LAZY_SYMBOL_POINTERS,
                                                           typeGOT),
+  ENTRY("__DATA", "__nl_symbol_ptr",  S_NON_LAZY_SYMBOL_POINTERS,
+                                                          typeNonLazyPointer),
   ENTRY("__DATA", "__thread_vars",    S_THREAD_LOCAL_VARIABLES,
                                                           typeThunkTLV),
   ENTRY("__DATA", "__thread_data",    S_THREAD_LOCAL_REGULAR,

lld/lib/ReaderWriter/MachO/StubsPass.cpp

@@ -68,11 +68,11 @@ private:
 //
 class NonLazyPointerAtom : public SimpleDefinedAtom {
 public:
-  NonLazyPointerAtom(const File &file, bool is64)
-    : SimpleDefinedAtom(file), _is64(is64) { }
+  NonLazyPointerAtom(const File &file, bool is64, ContentType contentType)
+    : SimpleDefinedAtom(file), _is64(is64), _contentType(contentType) { }
 
   ContentType contentType() const override {
-    return DefinedAtom::typeGOT;
+    return _contentType;
   }
 
   Alignment alignment() const override {
@@ -95,6 +95,7 @@ public:
 
 private:
   const bool _is64;
+  const ContentType _contentType;
 };
 
 //
@@ -239,9 +240,11 @@ public:
     SimpleDefinedAtom *helperCommonAtom =
         new (_file.allocator()) StubHelperCommonAtom(_file, _stubInfo);
     SimpleDefinedAtom *helperCacheNLPAtom =
-        new (_file.allocator()) NonLazyPointerAtom(_file, _ctx.is64Bit());
+        new (_file.allocator()) NonLazyPointerAtom(_file, _ctx.is64Bit(),
+                                    _stubInfo.stubHelperImageCacheContentType);
     SimpleDefinedAtom *helperBinderNLPAtom =
-        new (_file.allocator()) NonLazyPointerAtom(_file, _ctx.is64Bit());
+        new (_file.allocator()) NonLazyPointerAtom(_file, _ctx.is64Bit(),
+                                    _stubInfo.stubHelperImageCacheContentType);
     addReference(helperCommonAtom, _stubInfo.stubHelperCommonReferenceToCache,
                  helperCacheNLPAtom);
     addOptReference(

lld/test/mach-o/lazy-bind-x86_64.yaml

@@ -91,6 +91,10 @@ undefined-symbols:
 # CHECK-DYLIBS-NEXT:     offset
 # CHECK-DYLIBS-NEXT:      align 2^2 (4)
 
+# Make sure the __nl_symbol_ptr section is used instea of __got as this is x86_64
+# CHECK-DYLIBS:   sectname __nl_symbol_ptr
+# CHECK-DYLIBS-NEXT:    segname __DATA
+
 # CHECK-DYLIBS:           cmd LC_LOAD_DYLIB
 # CHECK-DYLIBS:          name /usr/lib/libbar.dylib (offset 24)
 # CHECK-DYLIBS:       current version 2.3.0