diff options
Diffstat (limited to 'source/Plugins/Process/Utility/UnwindLLDB.cpp')
| -rw-r--r-- | source/Plugins/Process/Utility/UnwindLLDB.cpp | 46 |
1 files changed, 36 insertions, 10 deletions
diff --git a/source/Plugins/Process/Utility/UnwindLLDB.cpp b/source/Plugins/Process/Utility/UnwindLLDB.cpp index 37fd4f489552..fc592e60d86d 100644 --- a/source/Plugins/Process/Utility/UnwindLLDB.cpp +++ b/source/Plugins/Process/Utility/UnwindLLDB.cpp @@ -172,8 +172,9 @@ UnwindLLDB::AddOneMoreFrame (ABI *abi) if (!reg_ctx_sp->IsValid()) { - // If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to that and return - // true. Subsequent calls to TryFallbackUnwindPlan() will return false. + // We failed to get a valid RegisterContext. + // See if the regctx below this on the stack has a fallback unwind plan it can use. + // Subsequent calls to TryFallbackUnwindPlan() will return false. if (m_frames[cur_idx - 1]->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) { return AddOneMoreFrame (abi); @@ -207,18 +208,35 @@ UnwindLLDB::AddOneMoreFrame (ABI *abi) // these. if (reg_ctx_sp->IsTrapHandlerFrame() == false) { - // If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to that and return - // true. Subsequent calls to TryFallbackUnwindPlan() will return false. - if (m_frames[cur_idx - 1]->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) + // See if we can find a fallback unwind plan for THIS frame. It may be + // that the UnwindPlan we're using for THIS frame was bad and gave us a + // bad CFA. + // If that's not it, then see if we can change the UnwindPlan for the frame + // below us ("NEXT") -- see if using that other UnwindPlan gets us a better + // unwind state. + if (reg_ctx_sp->TryFallbackUnwindPlan() == false + || reg_ctx_sp->GetCFA (cursor_sp->cfa) == false + || abi->CallFrameAddressIsValid(cursor_sp->cfa) == false) { - return AddOneMoreFrame (abi); + if (m_frames[cur_idx - 1]->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) + { + return AddOneMoreFrame (abi); + } + if (log) + { + log->Printf("%*sFrame %d did not get a valid CFA for this frame, stopping stack walk", + cur_idx < 100 ? cur_idx : 100, "", cur_idx); + } + goto unwind_done; } - if (log) + else { - log->Printf("%*sFrame %d did not get a valid CFA for this frame, stopping stack walk", - cur_idx < 100 ? cur_idx : 100, "", cur_idx); + if (log) + { + log->Printf("%*sFrame %d had a bad CFA value but we switched the UnwindPlan being used and got one that looks more realistic.", + cur_idx < 100 ? cur_idx : 100, "", cur_idx); + } } - goto unwind_done; } } if (!reg_ctx_sp->ReadPC (cursor_sp->start_pc)) @@ -366,6 +384,14 @@ UnwindLLDB::SearchForSavedLocationForRegister (uint32_t lldb_regnum, lldb_privat UnwindLLDB::RegisterSearchResult result; result = m_frames[frame_num]->reg_ctx_lldb_sp->SavedLocationForRegister (lldb_regnum, regloc); + // We descended down to the live register context aka stack frame 0 and are reading the value + // out of a live register. + if (result == UnwindLLDB::RegisterSearchResult::eRegisterFound + && regloc.type == UnwindLLDB::RegisterLocation::eRegisterInLiveRegisterContext) + { + return true; + } + // If we have unwind instructions saying that register N is saved in register M in the middle of // the stack (and N can equal M here, meaning the register was not used in this function), then // change the register number we're looking for to M and keep looking for a concrete location |