[mach-o] Add support for arm64 (AAarch64)

Most of the changes are in the new file ArchHandler_arm64.cpp.  But a few
things had to be fixed to support 16KB pages (instead of 4KB) which iOS arm64
requires.  In addition the StubInfo struct had to be expanded because
arm64 uses two instruction (ADRP/LDR) to load a global which requires two
relocations.  The other mach-o arches just needed one relocation.

llvm-svn: 217469

1 files changed, 15 insertions, 2 deletions

diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
index 7fc6fa95a8f..7a5c3c31235 100644
--- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
@@ -285,6 +285,12 @@ std::error_code processSymboledSection(DefinedAtom::ContentType atomType,
               Atom::Scope rScope = atomScope(rhs->scope);
               if (lScope != rScope)
                 return lScope < rScope;
+              // If same address and scope, see if one might be better as
+              // the alias.
+              bool lPrivate = (lhs->name.front() == 'l');
+              bool rPrivate = (rhs->name.front() == 'l');
+              if (lPrivate != rPrivate)
+                return lPrivate;
               // If same address and scope, sort by name.
               return lhs->name < rhs->name;
             });
@@ -315,8 +321,15 @@ std::error_code processSymboledSection(DefinedAtom::ContentType atomType,
   const Symbol *lastSym = nullptr;
   for (const Symbol *sym : symbols) {
     if (lastSym != nullptr) {
-      atomFromSymbol(atomType, section, file, lastSym->value, lastSym->name,
-                     lastSym->desc, atomScope(lastSym->scope), sym->value, copyRefs);
+      // Ignore any assembler added "ltmpNNN" symbol at start of section
+      // if there is another symbol at the start.
+      if ((lastSym->value != sym->value)
+          || lastSym->value != section.address
+          || !lastSym->name.startswith("ltmp")) {
+        atomFromSymbol(atomType, section, file, lastSym->value, lastSym->name,
+                       lastSym->desc, atomScope(lastSym->scope), sym->value,
+                       copyRefs);
+      }
     }
     lastSym = sym;
   }