From a375943d8231140ee5fa5e3f0b643105958575ec Mon Sep 17 00:00:00 2001
From: Sean Callanan <scallanan@apple.com>
Date: Mon, 26 Mar 2012 20:45:52 +0000
Subject: [PATCH] Made RuntimeDyldMachO support vanilla i386 relocations.  The
 algorithm is the same as that for x86_64.  Scattered relocations, a feature
 present in i386 but not on x86_64, are not yet supported.

llvm-svn: 153466
---
 .../RuntimeDyld/RuntimeDyldMachO.cpp          | 37 +++++++++++++++++++
 .../RuntimeDyld/RuntimeDyldMachO.h            |  7 ++++
 2 files changed, 44 insertions(+)

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index 0b72b567c30e..7130e0e17498 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -32,6 +32,14 @@ resolveRelocation(uint8_t *LocalAddress,
   // This just dispatches to the proper target specific routine.
   switch (CPUType) {
   default: llvm_unreachable("Unsupported CPU type!");
+  case mach::CTM_i386:
+    return resolveI386Relocation(LocalAddress,
+                                 FinalAddress,
+                                 (uintptr_t)Value,
+                                 isPCRel,
+                                 Type,
+                                 Size,
+                                 Addend);
   case mach::CTM_x86_64:
     return resolveX86_64Relocation(LocalAddress,
                                    FinalAddress,
@@ -51,6 +59,35 @@ resolveRelocation(uint8_t *LocalAddress,
   }
 }
 
+bool RuntimeDyldMachO::
+resolveI386Relocation(uint8_t *LocalAddress,
+                      uint64_t FinalAddress,
+                      uint64_t Value,
+                      bool isPCRel,
+                      unsigned Type,
+                      unsigned Size,
+                      int64_t Addend) {
+  if (isPCRel)
+    Value -= FinalAddress + 4; // see resolveX86_64Relocation
+
+  switch (Type) {
+  default:
+    llvm_unreachable("Invalid relocation type!");
+  case macho::RIT_Vanilla: {
+    uint8_t *p = LocalAddress;
+    uint64_t ValueToWrite = Value + Addend;
+    for (unsigned i = 0; i < Size; ++i) {
+      *p++ = (uint8_t)(ValueToWrite & 0xff);
+      ValueToWrite >>= 8;
+    }
+  }
+  case macho::RIT_Difference:
+  case macho::RIT_Generic_LocalDifference:
+  case macho::RIT_Generic_PreboundLazyPointer:
+    return Error("Relocation type not implemented yet!");
+  }
+}
+
 bool RuntimeDyldMachO::
 resolveX86_64Relocation(uint8_t *LocalAddress,
                         uint64_t FinalAddress,
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
index 6721703565b4..48a7253242fa 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
@@ -74,6 +74,13 @@ class RuntimeDyldMachO : public RuntimeDyldImpl {
                          unsigned Type,
                          unsigned Size,
                          int64_t Addend);
+  bool resolveI386Relocation(uint8_t *LocalAddress,
+                             uint64_t FinalAddress,
+                             uint64_t Value,
+                             bool isPCRel,
+                             unsigned Type,
+                             unsigned Size,
+                             int64_t Addend);
   bool resolveX86_64Relocation(uint8_t *LocalAddress,
                                uint64_t FinalAddress,
                                uint64_t Value,