First pass at supporting relocations. Relocations are written correctly to
the file now, however the relocated address is currently wrong. Fixing
that will require some deep pondering.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30207 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCMachOWriter.cpp b/lib/Target/PowerPC/PPCMachOWriter.cpp
index a7da371..f82ee34 100644
--- a/lib/Target/PowerPC/PPCMachOWriter.cpp
+++ b/lib/Target/PowerPC/PPCMachOWriter.cpp
@@ -12,6 +12,7 @@
//
//===----------------------------------------------------------------------===//
+#include "PPCRelocations.h"
#include "PPCTargetMachine.h"
#include "llvm/PassManager.h"
#include "llvm/CodeGen/MachOWriter.h"
@@ -22,11 +23,28 @@
class VISIBILITY_HIDDEN PPCMachOWriter : public MachOWriter {
public:
PPCMachOWriter(std::ostream &O, PPCTargetMachine &TM) : MachOWriter(O, TM) {
- // FIMXE: choose ppc64 when appropriate
- Header.cputype = MachOHeader::CPU_TYPE_POWERPC;
+ if (TM.getTargetData()->getPointerSizeInBits() == 64) {
+ Header.cputype = MachOHeader::CPU_TYPE_POWERPC64;
+ } else {
+ Header.cputype = MachOHeader::CPU_TYPE_POWERPC;
+ }
Header.cpusubtype = MachOHeader::CPU_SUBTYPE_POWERPC_ALL;
}
+ virtual void GetTargetRelocation(MachOSection &MOS, MachineRelocation &MR,
+ uint64_t Addr);
+
+ // Constants for the relocation r_type field.
+ // see <mach-o/ppc/reloc.h>
+ enum { PPC_RELOC_VANILLA, // generic relocation
+ PPC_RELOC_PAIR, // the second relocation entry of a pair
+ PPC_RELOC_BR14, // 14 bit branch displacement to word address
+ PPC_RELOC_BR24, // 24 bit branch displacement to word address
+ PPC_RELOC_HI16, // a PAIR follows with the low 16 bits
+ PPC_RELOC_LO16, // a PAIR follows with the high 16 bits
+ PPC_RELOC_HA16, // a PAIR follows, which is sign extended to 32b
+ PPC_RELOC_LO14 // LO16 with low 2 bits implicitly zero
+ };
};
}
@@ -39,3 +57,69 @@
FPM.add(EW);
FPM.add(createPPCCodeEmitterPass(TM, EW->getMachineCodeEmitter()));
}
+
+/// GetTargetRelocation - For the MachineRelocation MR, convert it to one or
+/// more PowerPC MachORelocation(s), add the new relocations to the
+/// MachOSection, and rewrite the instruction at the section offset if required
+/// by that relocation type.
+void PPCMachOWriter::GetTargetRelocation(MachOSection &MOS,
+ MachineRelocation &MR,
+ uint64_t Addr) {
+ // Keep track of whether or not this is an externally defined relocation.
+ uint32_t index = MOS.Index;
+ bool isExtern = false;
+
+ // Get the address of the instruction to rewrite
+ unsigned char *RelocPos = &MOS.SectionData[0] + MR.getMachineCodeOffset();
+
+ // Get the address of whatever it is we're relocating, if possible.
+ if (MR.isGlobalValue()) {
+ // determine whether or not its external and then figure out what section
+ // we put it in if it's a locally defined symbol.
+ } else if (MR.isString()) {
+ // lookup in global values?
+ } else {
+ assert((MR.isConstantPoolIndex() || MR.isJumpTableIndex()) &&
+ "Unhandled MachineRelocation type!");
+ }
+
+ switch ((PPC::RelocationType)MR.getRelocationType()) {
+ default: assert(0 && "Unknown PPC relocation type!");
+ case PPC::reloc_pcrel_bx:
+ case PPC::reloc_pcrel_bcx:
+ case PPC::reloc_absolute_low_ix:
+ assert(0 && "Unhandled PPC relocation type!");
+ break;
+ case PPC::reloc_absolute_high:
+ {
+ MachORelocation HA16(MR.getMachineCodeOffset(), index, false, 2, isExtern,
+ PPC_RELOC_HA16);
+ MachORelocation PAIR(Addr & 0xFFFF, 0xFFFFFF, false, 2, isExtern,
+ PPC_RELOC_PAIR);
+ outword(RelocBuffer, HA16.r_address);
+ outword(RelocBuffer, HA16.getPackedFields());
+ outword(RelocBuffer, PAIR.r_address);
+ outword(RelocBuffer, PAIR.getPackedFields());
+ }
+ MOS.nreloc += 2;
+ Addr += 0x8000;
+ *(unsigned *)RelocPos &= 0xFFFF0000;
+ *(unsigned *)RelocPos |= ((Addr >> 16) & 0xFFFF);
+ break;
+ case PPC::reloc_absolute_low:
+ {
+ MachORelocation LO16(MR.getMachineCodeOffset(), index, false, 2, isExtern,
+ PPC_RELOC_LO16);
+ MachORelocation PAIR(Addr >> 16, 0xFFFFFF, false, 2, isExtern,
+ PPC_RELOC_PAIR);
+ outword(RelocBuffer, LO16.r_address);
+ outword(RelocBuffer, LO16.getPackedFields());
+ outword(RelocBuffer, PAIR.r_address);
+ outword(RelocBuffer, PAIR.getPackedFields());
+ }
+ MOS.nreloc += 2;
+ *(unsigned *)RelocPos &= 0xFFFF0000;
+ *(unsigned *)RelocPos |= (Addr & 0xFFFF);
+ break;
+ }
+}