Improved support in RuntimeDyldMachO for generating

code that will be relocated into another memory space.
Now when relocations are resolved, the address of
the relocation in the host memory (where the JIT is)
is passed separately from the address that the
relocation will be at in the target memory (where
the code will run).

llvm-svn: 152264

1 files changed, 48 insertions, 16 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index c11b2c31c3f..e96a68925a0 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -22,29 +22,49 @@ using namespace llvm::object;
 namespace llvm {
 
 bool RuntimeDyldMachO::
-resolveRelocation(uint8_t *Address, uint64_t Value, bool isPCRel,
-                  unsigned Type, unsigned Size, int64_t Addend) {
+resolveRelocation(uint8_t *LocalAddress,
+                  uint64_t FinalAddress,
+                  uint64_t Value,
+                  bool isPCRel,
+                  unsigned Type,
+                  unsigned Size,
+                  int64_t Addend) {
   // This just dispatches to the proper target specific routine.
   switch (CPUType) {
   default: llvm_unreachable("Unsupported CPU type!");
   case mach::CTM_x86_64:
-    return resolveX86_64Relocation((uintptr_t)Address, (uintptr_t)Value,
-                                   isPCRel, Type, Size, Addend);
+    return resolveX86_64Relocation(LocalAddress,
+                                   FinalAddress,
+                                   (uintptr_t)Value,
+                                   isPCRel,
+                                   Type,
+                                   Size,
+                                   Addend);
   case mach::CTM_ARM:
-    return resolveARMRelocation((uintptr_t)Address, (uintptr_t)Value,
-                                isPCRel, Type, Size, Addend);
+    return resolveARMRelocation(LocalAddress,
+                                FinalAddress,
+                                (uintptr_t)Value,
+                                isPCRel,
+                                Type,
+                                Size,
+                                Addend);
   }
 }
 
 bool RuntimeDyldMachO::
-resolveX86_64Relocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
-                        unsigned Type, unsigned Size, int64_t Addend) {
+resolveX86_64Relocation(uint8_t *LocalAddress,
+                        uint64_t FinalAddress,
+                        uint64_t Value,
+                        bool isPCRel,
+                        unsigned Type,
+                        unsigned Size,
+                        int64_t Addend) {
   // If the relocation is PC-relative, the value to be encoded is the
   // pointer difference.
   if (isPCRel)
     // FIXME: It seems this value needs to be adjusted by 4 for an effective PC
     // address. Is that expected? Only for branches, perhaps?
-    Value -= Address + 4;
+    Value -= FinalAddress + 4;
 
   switch(Type) {
   default:
@@ -58,7 +78,7 @@ resolveX86_64Relocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
     Value += Addend;
     // Mask in the target value a byte at a time (we don't have an alignment
     // guarantee for the target address, so this is safest).
-    uint8_t *p = (uint8_t*)Address;
+    uint8_t *p = (uint8_t*)LocalAddress;
     for (unsigned i = 0; i < Size; ++i) {
       *p++ = (uint8_t)Value;
       Value >>= 8;
@@ -74,12 +94,17 @@ resolveX86_64Relocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
 }
 
 bool RuntimeDyldMachO::
-resolveARMRelocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
-                     unsigned Type, unsigned Size, int64_t Addend) {
+resolveARMRelocation(uint8_t *LocalAddress,
+                     uint64_t FinalAddress,
+                     uint64_t Value,
+                     bool isPCRel,
+                     unsigned Type,
+                     unsigned Size,
+                     int64_t Addend) {
   // If the relocation is PC-relative, the value to be encoded is the
   // pointer difference.
   if (isPCRel) {
-    Value -= Address;
+    Value -= FinalAddress;
     // ARM PCRel relocations have an effective-PC offset of two instructions
     // (four bytes in Thumb mode, 8 bytes in ARM mode).
     // FIXME: For now, assume ARM mode.
@@ -92,7 +117,7 @@ resolveARMRelocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
   case macho::RIT_Vanilla: {
     // Mask in the target value a byte at a time (we don't have an alignment
     // guarantee for the target address, so this is safest).
-    uint8_t *p = (uint8_t*)Address;
+    uint8_t *p = (uint8_t*)LocalAddress;
     for (unsigned i = 0; i < Size; ++i) {
       *p++ = (uint8_t)Value;
       Value >>= 8;
@@ -102,7 +127,7 @@ resolveARMRelocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
   case macho::RIT_ARM_Branch24Bit: {
     // Mask the value into the target address. We know instructions are
     // 32-bit aligned, so we can do it all at once.
-    uint32_t *p = (uint32_t*)Address;
+    uint32_t *p = (uint32_t*)LocalAddress;
     // The low two bits of the value are not encoded.
     Value >>= 2;
     // Mask the value to 24 bits.
@@ -569,6 +594,7 @@ void RuntimeDyldMachO::reassignSectionAddress(unsigned SectionID,
   for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
     RelocationEntry &RE = Relocs[i];
     uint8_t *Target = (uint8_t*)Sections[RE.SectionID].base() + RE.Offset;
+    uint64_t FinalTarget = (uint64_t)SectionLoadAddress[RE.SectionID] + RE.Offset;
     bool isPCRel = (RE.Data >> 24) & 1;
     unsigned Type = (RE.Data >> 28) & 0xf;
     unsigned Size = 1 << ((RE.Data >> 25) & 3);
@@ -580,7 +606,13 @@ void RuntimeDyldMachO::reassignSectionAddress(unsigned SectionID,
           << ", type: " << Type << ", Size: " << Size << ", Addend: "
           << RE.Addend << ").\n");
 
-    resolveRelocation(Target, Addr, isPCRel, Type, Size, RE.Addend);
+    resolveRelocation(Target,
+                      FinalTarget,
+                      Addr,
+                      isPCRel,
+                      Type,
+                      Size,
+                      RE.Addend);
   }
 }