Author: labath Date: Mon Jun 19 07:39:34 2017 New Revision: 305687 URL: http://llvm.org/viewvc/llvm-project?rev=305687&view=rev Log: Tweak SysV_arm64 function entry unwind plan
Summary: The motivation for this is to make sure the first row of the plan compares equal to the first row of a generic debug_frame unwind plan. Right now, the code in FuncUnwinders::GetUnwindPlanAtNonCallSite considers them unequal because they specify the return address in a different way (SetReturnAddressRegister(LR) vs. an explicit PC=LR rule). This means that FuncUnwinders would always choose the debug_frame unwind plan, which is not correct, as that one is usually not correct at all locations. Right now this is basically a noop because we don't have parse any debug_frame plans, but it fixes some test failures when merging D33504 in. I have to say I don't understand the full implications of the switch to SetReturnAddressRegister() way of doing things, but given that all of our other unwind plans (eh_frame, instruction profiling) do it this way, it sounds like the right thing to do. Reviewers: tberghammer, jasonmolenda, omjavaid Subscribers: aemerson, javed.absar, kristof.beyls, lldb-commits Differential Revision: https://reviews.llvm.org/D34199 Modified: lldb/trunk/source/Plugins/ABI/SysV-arm64/ABISysV_arm64.cpp Modified: lldb/trunk/source/Plugins/ABI/SysV-arm64/ABISysV_arm64.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ABI/SysV-arm64/ABISysV_arm64.cpp?rev=305687&r1=305686&r2=305687&view=diff ============================================================================== --- lldb/trunk/source/Plugins/ABI/SysV-arm64/ABISysV_arm64.cpp (original) +++ lldb/trunk/source/Plugins/ABI/SysV-arm64/ABISysV_arm64.cpp Mon Jun 19 07:39:34 2017 @@ -1951,22 +1951,20 @@ bool ABISysV_arm64::CreateFunctionEntryU uint32_t lr_reg_num = arm64_dwarf::lr; uint32_t sp_reg_num = arm64_dwarf::sp; - uint32_t pc_reg_num = arm64_dwarf::pc; UnwindPlan::RowSP row(new UnwindPlan::Row); // Our previous Call Frame Address is the stack pointer row->GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 0); - // Our previous PC is in the LR - row->SetRegisterLocationToRegister(pc_reg_num, lr_reg_num, true); - unwind_plan.AppendRow(row); + unwind_plan.SetReturnAddressRegister(lr_reg_num); // All other registers are the same. unwind_plan.SetSourceName("arm64 at-func-entry default"); unwind_plan.SetSourcedFromCompiler(eLazyBoolNo); + unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo); return true; } _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
