[RuntimeDyld] Add support for MachO __jump_table and __pointers sections, and

SECTDIFF relocations on 32-bit x86.

This fixes several of the MCJIT regression test failures that show up on 32-bit
builds.

<rdar://problem/16886294>

llvm-svn: 208635

1 files changed, 15 insertions, 7 deletions

diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index d0a56aa930e..fa95eca669f 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -1158,13 +1158,7 @@ error_code MachOObjectFile::getLibraryPath(DataRefImpl LibData,
 }
 
 basic_symbol_iterator MachOObjectFile::symbol_begin_impl() const {
-  DataRefImpl DRI;
-  if (!SymtabLoadCmd)
-    return basic_symbol_iterator(SymbolRef(DRI, this));
-
-  MachO::symtab_command Symtab = getSymtabLoadCommand();
-  DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Symtab.symoff));
-  return basic_symbol_iterator(SymbolRef(DRI, this));
+  return getSymbolByIndex(0);
 }
 
 basic_symbol_iterator MachOObjectFile::symbol_end_impl() const {
@@ -1182,6 +1176,20 @@ basic_symbol_iterator MachOObjectFile::symbol_end_impl() const {
   return basic_symbol_iterator(SymbolRef(DRI, this));
 }
 
+basic_symbol_iterator MachOObjectFile::getSymbolByIndex(unsigned Index) const {
+  DataRefImpl DRI;
+  if (!SymtabLoadCmd)
+    return basic_symbol_iterator(SymbolRef(DRI, this));
+
+  MachO::symtab_command Symtab = getSymtabLoadCommand();
+  assert(Index < Symtab.nsyms && "Requested symbol index is out of range.");
+  unsigned SymbolTableEntrySize =
+    is64Bit() ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
+  DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Symtab.symoff));
+  DRI.p += Index * SymbolTableEntrySize;
+  return basic_symbol_iterator(SymbolRef(DRI, this));
+}
+
 section_iterator MachOObjectFile::section_begin() const {
   DataRefImpl DRI;
   return section_iterator(SectionRef(DRI, this));