+const MCExpr *TargetLoweringObjectFileMachO::getIndirectSymViaGOTPCRel(
+ const MCSymbol *Sym, const MCValue &MV, int64_t Offset,
+ MachineModuleInfo *MMI, MCStreamer &Streamer) const {
+ // Although MachO 32-bit targets do not explicitly have a GOTPCREL relocation
+ // as 64-bit do, we replace the GOT equivalent by accessing the final symbol
+ // through a non_lazy_ptr stub instead. One advantage is that it allows the
+ // computation of deltas to final external symbols. Example:
+ //
+ // _extgotequiv:
+ // .long _extfoo
+ //
+ // _delta:
+ // .long _extgotequiv-_delta
+ //
+ // is transformed to:
+ //
+ // _delta:
+ // .long L_extfoo$non_lazy_ptr-(_delta+0)
+ //
+ // .section __IMPORT,__pointers,non_lazy_symbol_pointers
+ // L_extfoo$non_lazy_ptr:
+ // .indirect_symbol _extfoo
+ // .long 0
+ //
+ MachineModuleInfoMachO &MachOMMI =
+ MMI->getObjFileInfo<MachineModuleInfoMachO>();
+ MCContext &Ctx = getContext();
+
+ // The offset must consider the original displacement from the base symbol
+ // since 32-bit targets don't have a GOTPCREL to fold the PC displacement.
+ Offset = -MV.getConstant();
+ const MCSymbol *BaseSym = &MV.getSymB()->getSymbol();
+
+ // Access the final symbol via sym$non_lazy_ptr and generate the appropriated
+ // non_lazy_ptr stubs.
+ SmallString<128> Name;
+ StringRef Suffix = "$non_lazy_ptr";
+ Name += MMI->getModule()->getDataLayout().getPrivateGlobalPrefix();
+ Name += Sym->getName();
+ Name += Suffix;
+ MCSymbol *Stub = Ctx.getOrCreateSymbol(Name);
+
+ MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(Stub);
+ if (!StubSym.getPointer())
+ StubSym = MachineModuleInfoImpl::
+ StubValueTy(const_cast<MCSymbol *>(Sym), true /* access indirectly */);
+
+ const MCExpr *BSymExpr =
+ MCSymbolRefExpr::create(BaseSym, MCSymbolRefExpr::VK_None, Ctx);
+ const MCExpr *LHS =
+ MCSymbolRefExpr::create(Stub, MCSymbolRefExpr::VK_None, Ctx);
+
+ if (!Offset)
+ return MCBinaryExpr::createSub(LHS, BSymExpr, Ctx);
+
+ const MCExpr *RHS =
+ MCBinaryExpr::createAdd(BSymExpr, MCConstantExpr::create(Offset, Ctx), Ctx);
+ return MCBinaryExpr::createSub(LHS, RHS, Ctx);
+}
+