From e87dadc44b1544c35e13cf48dfe167109929a944 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Tue, 30 Apr 2013 15:40:54 +0000
Subject: [PATCH] Fix Addend computation for non external relocations on Macho.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180790 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Object/MachO.h                   |  1 +
 .../RuntimeDyld/RuntimeDyldMachO.cpp          | 38 +++++--------------
 lib/Object/MachOObjectFile.cpp                | 10 +++++
 .../MCJIT/non-extern-addend.ll                | 12 ++++++
 4 files changed, 33 insertions(+), 28 deletions(-)
 create mode 100644 test/ExecutionEngine/MCJIT/non-extern-addend.ll

diff --git a/include/llvm/Object/MachO.h b/include/llvm/Object/MachO.h
index 17a8fc2bff7..14cd4d767d4 100644
--- a/include/llvm/Object/MachO.h
+++ b/include/llvm/Object/MachO.h
@@ -130,6 +130,7 @@ public:
   unsigned getAnyRelocationPCRel(const macho::RelocationEntry &RE) const;
   unsigned getAnyRelocationLength(const macho::RelocationEntry &RE) const;
   unsigned getAnyRelocationType(const macho::RelocationEntry &RE) const;
+  SectionRef getRelocationSection(const macho::RelocationEntry &RE) const;
 
   // Walk load commands.
   LoadCommandInfo getFirstLoadCommandInfo() const;
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index 6054b2ab79c..b3467a9ab38 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -232,12 +232,12 @@ void RuntimeDyldMachO::processRelocationRef(unsigned SectionID,
   unsigned Size = MachO->getAnyRelocationLength(RE);
   uint64_t Offset;
   RelI.getOffset(Offset);
-  if (isExtern) {
-    uint8_t *LocalAddress = Section.Address + Offset;
-    unsigned NumBytes = 1 << Size;
-    uint64_t Addend = 0;
-    memcpy(&Addend, LocalAddress, NumBytes);
+  uint8_t *LocalAddress = Section.Address + Offset;
+  unsigned NumBytes = 1 << Size;
+  uint64_t Addend = 0;
+  memcpy(&Addend, LocalAddress, NumBytes);
 
+  if (isExtern) {
     // Obtain the symbol name which is referenced in the relocation
     SymbolRef Symbol;
     RelI.getSymbol(Symbol);
@@ -260,29 +260,11 @@ void RuntimeDyldMachO::processRelocationRef(unsigned SectionID,
       }
     }
   } else {
-    error_code err;
-    uint8_t sectionIndex = static_cast<uint8_t>(RelType & 0xFF);
-    section_iterator si = Obj.begin_sections(),
-                     se = Obj.end_sections();
-    for (uint8_t i = 1; i < sectionIndex; i++) {
-      error_code err;
-      si.increment(err);
-      if (si == se)
-        break;
-    }
-    assert(si != se && "No section containing relocation!");
-    Value.SectionID = findOrEmitSection(Obj, *si, true, ObjSectionToID);
-    Value.Addend = 0;
-    // FIXME: The size and type of the relocation determines if we can
-    // encode an Addend in the target location itself, and if so, how many
-    // bytes we should read in order to get it. We don't yet support doing
-    // that, and just assuming it's sizeof(intptr_t) is blatantly wrong.
-    //Value.Addend = *(const intptr_t *)Target;
-    if (Value.Addend) {
-      // The MachO addend is an offset from the current section.  We need it
-      // to be an offset from the destination section
-      Value.Addend += Section.ObjAddress - Sections[Value.SectionID].ObjAddress;
-    }
+    SectionRef Sec = MachO->getRelocationSection(RE);
+    Value.SectionID = findOrEmitSection(Obj, Sec, true, ObjSectionToID);
+    uint64_t Addr;
+    Sec.getAddress(Addr);
+    Value.Addend = Addend - Addr;
   }
 
   if (Arch == Triple::arm && (RelType & 0xf) == macho::RIT_ARM_Branch24Bit) {
diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index f6840b8c15d..dfd8d3d3dd1 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -1414,6 +1414,16 @@ MachOObjectFile::getAnyRelocationType(const macho::RelocationEntry &RE) const {
   return getPlainRelocationType(this, RE);
 }
 
+SectionRef
+MachOObjectFile::getRelocationSection(const macho::RelocationEntry &RE) const {
+  if (isRelocationScattered(RE) || getPlainRelocationExternal(RE))
+    return *end_sections();
+  unsigned SecNum = getPlainRelocationSymbolNum(RE) - 1;
+  DataRefImpl DRI;
+  DRI.d.a = SecNum;
+  return SectionRef(DRI, this);
+}
+
 MachOObjectFile::LoadCommandInfo
 MachOObjectFile::getFirstLoadCommandInfo() const {
   MachOObjectFile::LoadCommandInfo Load;
diff --git a/test/ExecutionEngine/MCJIT/non-extern-addend.ll b/test/ExecutionEngine/MCJIT/non-extern-addend.ll
new file mode 100644
index 00000000000..3a6e6344120
--- /dev/null
+++ b/test/ExecutionEngine/MCJIT/non-extern-addend.ll
@@ -0,0 +1,12 @@
+; RUN: %lli_mcjit %s > /dev/null
+
+define i32 @foo(i32 %X, i32 %Y, double %A) {
+	%cond212 = fcmp ueq double %A, 2.000000e+00		; <i1> [#uses=1]
+	%cast110 = zext i1 %cond212 to i32		; <i32> [#uses=1]
+	ret i32 %cast110
+}
+
+define i32 @main() {
+	%reg212 = call i32 @foo( i32 0, i32 1, double 1.000000e+00 )		; <i32> [#uses=1]
+	ret i32 %reg212
+}
-- 
2.34.1