diff options
Diffstat (limited to 'source/Plugins/Process/Utility/RegisterContextLLDB.cpp')
| -rw-r--r-- | source/Plugins/Process/Utility/RegisterContextLLDB.cpp | 97 |
1 files changed, 54 insertions, 43 deletions
diff --git a/source/Plugins/Process/Utility/RegisterContextLLDB.cpp b/source/Plugins/Process/Utility/RegisterContextLLDB.cpp index efda0edb70c9..8bbaeb8e9a59 100644 --- a/source/Plugins/Process/Utility/RegisterContextLLDB.cpp +++ b/source/Plugins/Process/Utility/RegisterContextLLDB.cpp @@ -470,11 +470,13 @@ RegisterContextLLDB::InitializeNonZerothFrame() return; } - bool resolve_tail_call_address = true; // m_current_pc can be one past the address range of the function... - // This will handle the case where the saved pc does not point to - // a function/symbol because it is beyond the bounds of the correct - // function and there's no symbol there. ResolveSymbolContextForAddress - // will fail to find a symbol, back up the pc by 1 and re-search. + bool resolve_tail_call_address = false; // m_current_pc can be one past the address range of the function... + // If the saved pc does not point to a function/symbol because it is + // beyond the bounds of the correct function and there's no symbol there, + // we do *not* want ResolveSymbolContextForAddress to back up the pc by 1, + // because then we might not find the correct unwind information later. + // Instead, let ResolveSymbolContextForAddress fail, and handle the case + // via decr_pc_and_recompute_addr_range below. const uint32_t resolve_scope = eSymbolContextFunction | eSymbolContextSymbol; uint32_t resolved_scope = pc_module_sp->ResolveSymbolContextForAddress (m_current_pc, resolve_scope, @@ -1390,45 +1392,28 @@ RegisterContextLLDB::SavedLocationForRegister (uint32_t lldb_regnum, lldb_privat } } - if (have_unwindplan_regloc == false) - { - // Did the UnwindPlan fail to give us the caller's stack pointer? - // The stack pointer is defined to be the same as THIS frame's CFA, so return the CFA value as - // the caller's stack pointer. This is true on x86-32/x86-64 at least. - - RegisterNumber sp_regnum (m_thread, eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP); - if (sp_regnum.GetAsKind (eRegisterKindLLDB) != LLDB_INVALID_REGNUM - && sp_regnum.GetAsKind (eRegisterKindLLDB) == regnum.GetAsKind (eRegisterKindLLDB)) - { - // make sure we won't lose precision copying an addr_t (m_cfa) into a uint64_t (.inferred_value) - assert (sizeof (addr_t) <= sizeof (uint64_t)); - regloc.type = UnwindLLDB::RegisterLocation::eRegisterValueInferred; - regloc.location.inferred_value = m_cfa; - m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = regloc; - UnwindLogMsg ("supplying caller's stack pointer %s (%d) value, computed from CFA", - regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); - return UnwindLLDB::RegisterSearchResult::eRegisterFound; - } - } - ExecutionContext exe_ctx(m_thread.shared_from_this()); Process *process = exe_ctx.GetProcessPtr(); if (have_unwindplan_regloc == false) { - // If a volatile register is being requested, we don't want to forward the next frame's register contents - // up the stack -- the register is not retrievable at this frame. + // If the UnwindPlan failed to give us an unwind location for this register, we may be able to fall back + // to some ABI-defined default. For example, some ABIs allow to determine the caller's SP via the CFA. + // Also, the ABI may set volatile registers to the undefined state. ABI *abi = process ? process->GetABI().get() : NULL; if (abi) { const RegisterInfo *reg_info = GetRegisterInfoAtIndex(regnum.GetAsKind (eRegisterKindLLDB)); - if (reg_info && abi->RegisterIsVolatile (reg_info)) + if (reg_info && abi->GetFallbackRegisterLocation (reg_info, unwindplan_regloc)) { - UnwindLogMsg ("did not supply reg location for %s (%d) because it is volatile", + UnwindLogMsg ("supplying caller's saved %s (%d)'s location using ABI default", regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); - return UnwindLLDB::RegisterSearchResult::eRegisterIsVolatile; + have_unwindplan_regloc = true; } } + } + if (have_unwindplan_regloc == false) + { if (IsFrameZero ()) { // This is frame 0 - we should return the actual live register context value @@ -1468,15 +1453,33 @@ RegisterContextLLDB::SavedLocationForRegister (uint32_t lldb_regnum, lldb_privat return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; } + if (unwindplan_regloc.IsUndefined()) + { + UnwindLogMsg ("did not supply reg location for %s (%d) because it is volatile", + regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); + return UnwindLLDB::RegisterSearchResult::eRegisterIsVolatile; + } + if (unwindplan_regloc.IsSame()) { - regloc.type = UnwindLLDB::RegisterLocation::eRegisterInRegister; - regloc.location.register_number = regnum.GetAsKind (eRegisterKindLLDB); - m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = regloc; - UnwindLogMsg ("supplying caller's register %s (%d), saved in register %s (%d)", - regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB), - regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); - return UnwindLLDB::RegisterSearchResult::eRegisterFound; + if (IsFrameZero() == false + && (regnum.GetAsKind (eRegisterKindGeneric) == LLDB_REGNUM_GENERIC_PC + || regnum.GetAsKind (eRegisterKindGeneric) == LLDB_REGNUM_GENERIC_RA)) + { + UnwindLogMsg ("register %s (%d) is marked as 'IsSame' - it is a pc or return address reg on a non-zero frame -- treat as if we have no information", + regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); + return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; + } + else + { + regloc.type = UnwindLLDB::RegisterLocation::eRegisterInRegister; + regloc.location.register_number = regnum.GetAsKind (eRegisterKindLLDB); + m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = regloc; + UnwindLogMsg ("supplying caller's register %s (%d), saved in register %s (%d)", + regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB), + regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); + return UnwindLLDB::RegisterSearchResult::eRegisterFound; + } } if (unwindplan_regloc.IsCFAPlusOffset()) @@ -1536,7 +1539,7 @@ RegisterContextLLDB::SavedLocationForRegister (uint32_t lldb_regnum, lldb_privat dwarfexpr.SetRegisterKind (unwindplan_registerkind); Value result; Error error; - if (dwarfexpr.Evaluate (&exe_ctx, NULL, NULL, this, 0, NULL, result, &error)) + if (dwarfexpr.Evaluate (&exe_ctx, nullptr, nullptr, this, 0, nullptr, nullptr, result, &error)) { addr_t val; val = result.GetScalar().ULongLong(); @@ -1836,7 +1839,7 @@ RegisterContextLLDB::ReadCFAValueForRow (lldb::RegisterKind row_register_kind, dwarfexpr.SetRegisterKind (row_register_kind); Value result; Error error; - if (dwarfexpr.Evaluate (&exe_ctx, NULL, NULL, this, 0, NULL, result, &error)) + if (dwarfexpr.Evaluate (&exe_ctx, nullptr, nullptr, this, 0, nullptr, nullptr, result, &error)) { cfa_value = result.GetScalar().ULongLong(); @@ -1897,12 +1900,13 @@ RegisterContextLLDB::ReadGPRValue (lldb::RegisterKind register_kind, uint32_t re bool pc_register = false; uint32_t generic_regnum; - if (register_kind == eRegisterKindGeneric && regnum == LLDB_REGNUM_GENERIC_PC) + if (register_kind == eRegisterKindGeneric + && (regnum == LLDB_REGNUM_GENERIC_PC || regnum == LLDB_REGNUM_GENERIC_RA)) { pc_register = true; } else if (m_thread.GetRegisterContext()->ConvertBetweenRegisterKinds (register_kind, regnum, eRegisterKindGeneric, generic_regnum) - && generic_regnum == LLDB_REGNUM_GENERIC_PC) + && (generic_regnum == LLDB_REGNUM_GENERIC_PC || generic_regnum == LLDB_REGNUM_GENERIC_RA)) { pc_register = true; } @@ -1944,9 +1948,16 @@ RegisterContextLLDB::ReadRegister (const RegisterInfo *reg_info, RegisterValue & return m_thread.GetRegisterContext()->ReadRegister (reg_info, value); } + bool is_pc_regnum = false; + if (reg_info->kinds[eRegisterKindGeneric] == LLDB_REGNUM_GENERIC_PC + || reg_info->kinds[eRegisterKindGeneric] == LLDB_REGNUM_GENERIC_RA) + { + is_pc_regnum = true; + } + lldb_private::UnwindLLDB::RegisterLocation regloc; // Find out where the NEXT frame saved THIS frame's register contents - if (!m_parent_unwind.SearchForSavedLocationForRegister (lldb_regnum, regloc, m_frame_number - 1, false)) + if (!m_parent_unwind.SearchForSavedLocationForRegister (lldb_regnum, regloc, m_frame_number - 1, is_pc_regnum)) return false; return ReadRegisterValueFromRegisterLocation (regloc, reg_info, value); |