Updated llvm-objdump to display local relocations in Mach-O binaries

Summary:
llvm-objdump's Mach-O parser was updated in r306037 to display external
relocations for MH_KEXT_BUNDLE file types. This change extends the Macho-O
parser to display local relocations for MH_PRELOAD files. When used with
the -macho option relocations will be displayed in a historical format.

All tests are passing for llvm, clang, and lld. llvm-objdump builds without
compiler warnings.

rdar://35778019

Reviewers: enderby

Reviewed By: enderby

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41199

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320832 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 23 insertions, 1 deletions

diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 83becc41319..2e3415618e5 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -1960,6 +1960,7 @@ MachOObjectFile::section_rel_end(DataRefImpl Sec) const {
 
 relocation_iterator MachOObjectFile::extrel_begin() const {
   DataRefImpl Ret;
+  // for DYSYMTAB symbols, Ret.d.a == 0 for external relocations
   Ret.d.a = 0; // Would normally be a section index.
   Ret.d.b = 0; // Index into the external relocations
   return relocation_iterator(RelocationRef(Ret, this));
@@ -1968,11 +1969,29 @@ relocation_iterator MachOObjectFile::extrel_begin() const {
 relocation_iterator MachOObjectFile::extrel_end() const {
   MachO::dysymtab_command DysymtabLoadCmd = getDysymtabLoadCommand();
   DataRefImpl Ret;
+  // for DYSYMTAB symbols, Ret.d.a == 0 for external relocations
   Ret.d.a = 0; // Would normally be a section index.
   Ret.d.b = DysymtabLoadCmd.nextrel; // Index into the external relocations
   return relocation_iterator(RelocationRef(Ret, this));
 }
 
+relocation_iterator MachOObjectFile::locrel_begin() const {
+  DataRefImpl Ret;
+  // for DYSYMTAB symbols, Ret.d.a == 1 for local relocations
+  Ret.d.a = 1; // Would normally be a section index.
+  Ret.d.b = 0; // Index into the local relocations
+  return relocation_iterator(RelocationRef(Ret, this));
+}
+
+relocation_iterator MachOObjectFile::locrel_end() const {
+  MachO::dysymtab_command DysymtabLoadCmd = getDysymtabLoadCommand();
+  DataRefImpl Ret;
+  // for DYSYMTAB symbols, Ret.d.a == 1 for local relocations
+  Ret.d.a = 1; // Would normally be a section index.
+  Ret.d.b = DysymtabLoadCmd.nlocrel; // Index into the local relocations
+  return relocation_iterator(RelocationRef(Ret, this));
+}
+
 void MachOObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
   ++Rel.d.b;
 }
@@ -4301,7 +4320,10 @@ MachOObjectFile::getRelocation(DataRefImpl Rel) const {
     }
   } else {
     MachO::dysymtab_command DysymtabLoadCmd = getDysymtabLoadCommand();
-    Offset = DysymtabLoadCmd.extreloff; // Offset to the external relocations
+    if (Rel.d.a == 0)
+      Offset = DysymtabLoadCmd.extreloff; // Offset to the external relocations
+    else
+      Offset = DysymtabLoadCmd.locreloff; // Offset to the local relocations
   }
 
   auto P = reinterpret_cast<const MachO::any_relocation_info *>(