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[lldb] Remove unused UnwindPlan functions (#134630)

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`GetLSDAAddress` and `GetPersonalityRoutinePtrAddress` are unused and
they create a bit of a problem for discontinuous functions, because the
unwind plan for these consists of multiple eh_frame descriptors and (at
least in theory) each of them could have a different value for these
entities.

We could say we only support functions for which these are always the
same, or create some sort of a Address2LSDA lookup map, but I think it's
better to leave this question to someone who actually needs this.
This commit is contained in:
Pavel Labath
2025-04-09 11:04:45 +02:00
committed by GitHub
parent 20d1888cbe
commit ea7dd70b53
6 changed files with 3 additions and 126 deletions
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13
lldb/include/lldb/Symbol/FuncUnwinders.h
View File

@@ -61,19 +61,6 @@ public:
});
}
// A function may have a Language Specific Data Area specified -- a block of
// data in
// the object file which is used in the processing of an exception throw /
// catch. If any of the UnwindPlans have the address of the LSDA region for
// this function, this will return it.
Address GetLSDAAddress(Target &target);
// A function may have a Personality Routine associated with it -- used in the
// processing of throwing an exception. If any of the UnwindPlans have the
// address of the personality routine, this will return it. Read the target-
// pointer at this address to get the personality function address.
Address GetPersonalityRoutinePtrAddress(Target &target);
// The following methods to retrieve specific unwind plans should rarely be
// used. Instead, clients should ask for the *behavior* they are looking for,
// using one of the above UnwindPlan retrieval methods.

19
lldb/include/lldb/Symbol/UnwindPlan.h
View File

@@ -536,22 +536,10 @@ public:
m_plan_is_sourced_from_compiler = eLazyBoolCalculate;
m_plan_is_valid_at_all_instruction_locations = eLazyBoolCalculate;
m_plan_is_for_signal_trap = eLazyBoolCalculate;
m_lsda_address.Clear();
m_personality_func_addr.Clear();
}
const RegisterInfo *GetRegisterInfo(Thread *thread, uint32_t reg_num) const;
Address GetLSDAAddress() const { return m_lsda_address; }
void SetLSDAAddress(Address lsda_addr) { m_lsda_address = lsda_addr; }
Address GetPersonalityFunctionPtr() const { return m_personality_func_addr; }
void SetPersonalityFunctionPtr(Address presonality_func_ptr) {
m_personality_func_addr = presonality_func_ptr;
}
private:
std::vector<Row> m_row_list;
std::vector<AddressRange> m_plan_valid_ranges;
@@ -566,13 +554,6 @@ private:
lldb_private::LazyBool m_plan_is_sourced_from_compiler;
lldb_private::LazyBool m_plan_is_valid_at_all_instruction_locations;
lldb_private::LazyBool m_plan_is_for_signal_trap;
Address m_lsda_address; // Where the language specific data area exists in the
// module - used
// in exception handling.
Address m_personality_func_addr; // The address of a pointer to the
// personality function - used in
// exception handling.
}; // class UnwindPlan
} // namespace lldb_private

12
lldb/source/Symbol/CompactUnwindInfo.cpp
View File

@@ -741,9 +741,6 @@ bool CompactUnwindInfo::CreateUnwindPlan_x86_64(Target &target,
unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
unwind_plan.SetRegisterKind(eRegisterKindEHFrame);
unwind_plan.SetLSDAAddress(function_info.lsda_address);
unwind_plan.SetPersonalityFunctionPtr(function_info.personality_ptr_address);
UnwindPlan::Row row;
const int wordsize = 8;
@@ -1011,9 +1008,6 @@ bool CompactUnwindInfo::CreateUnwindPlan_i386(Target &target,
unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
unwind_plan.SetRegisterKind(eRegisterKindEHFrame);
unwind_plan.SetLSDAAddress(function_info.lsda_address);
unwind_plan.SetPersonalityFunctionPtr(function_info.personality_ptr_address);
UnwindPlan::Row row;
const int wordsize = 4;
@@ -1306,9 +1300,6 @@ bool CompactUnwindInfo::CreateUnwindPlan_arm64(Target &target,
unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
unwind_plan.SetRegisterKind(eRegisterKindEHFrame);
unwind_plan.SetLSDAAddress(function_info.lsda_address);
unwind_plan.SetPersonalityFunctionPtr(function_info.personality_ptr_address);
UnwindPlan::Row row;
const int wordsize = 8;
@@ -1437,9 +1428,6 @@ bool CompactUnwindInfo::CreateUnwindPlan_armv7(Target &target,
unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
unwind_plan.SetRegisterKind(eRegisterKindEHFrame);
unwind_plan.SetLSDAAddress(function_info.lsda_address);
unwind_plan.SetPersonalityFunctionPtr(function_info.personality_ptr_address);
UnwindPlan::Row row;
const int wordsize = 4;

36
lldb/source/Symbol/DWARFCallFrameInfo.cpp
View File

@@ -583,43 +583,13 @@ bool DWARFCallFrameInfo::FDEToUnwindPlan(dw_offset_t dwarf_offset,
m_objfile.GetSectionList());
range.SetByteSize(range_len);
addr_t lsda_data_file_address = LLDB_INVALID_ADDRESS;
// Skip the LSDA, if present.
if (cie->augmentation[0] == 'z')
offset += (uint32_t)m_cfi_data.GetULEB128(&offset);
if (cie->augmentation[0] == 'z') {
uint32_t aug_data_len = (uint32_t)m_cfi_data.GetULEB128(&offset);
if (aug_data_len != 0 && cie->lsda_addr_encoding != DW_EH_PE_omit) {
lldb::offset_t saved_offset = offset;
lsda_data_file_address =
GetGNUEHPointer(m_cfi_data, &offset, cie->lsda_addr_encoding,
pc_rel_addr, text_addr, data_addr);
if (offset - saved_offset != aug_data_len) {
// There is more in the augmentation region than we know how to process;
// don't read anything.
lsda_data_file_address = LLDB_INVALID_ADDRESS;
}
offset = saved_offset;
}
offset += aug_data_len;
}
unwind_plan.SetUnwindPlanForSignalTrap(
strchr(cie->augmentation, 'S') ? eLazyBoolYes : eLazyBoolNo);
Address lsda_data;
Address personality_function_ptr;
if (lsda_data_file_address != LLDB_INVALID_ADDRESS &&
cie->personality_loc != LLDB_INVALID_ADDRESS) {
m_objfile.GetModule()->ResolveFileAddress(lsda_data_file_address,
lsda_data);
m_objfile.GetModule()->ResolveFileAddress(cie->personality_loc,
personality_function_ptr);
}
if (lsda_data.IsValid() && personality_function_ptr.IsValid()) {
unwind_plan.SetLSDAAddress(lsda_data);
unwind_plan.SetPersonalityFunctionPtr(personality_function_ptr);
}
uint32_t code_align = cie->code_align;
int32_t data_align = cie->data_align;

36
lldb/source/Symbol/FuncUnwinders.cpp
View File

@@ -537,39 +537,3 @@ FuncUnwinders::GetUnwindAssemblyProfiler(Target &target) {
}
return assembly_profiler_sp;
}
Address FuncUnwinders::GetLSDAAddress(Target &target) {
Address lsda_addr;
std::shared_ptr<const UnwindPlan> unwind_plan_sp =
GetEHFrameUnwindPlan(target);
if (unwind_plan_sp.get() == nullptr) {
unwind_plan_sp = GetCompactUnwindUnwindPlan(target);
}
if (unwind_plan_sp.get() == nullptr) {
unwind_plan_sp = GetObjectFileUnwindPlan(target);
}
if (unwind_plan_sp.get() && unwind_plan_sp->GetLSDAAddress().IsValid()) {
lsda_addr = unwind_plan_sp->GetLSDAAddress();
}
return lsda_addr;
}
Address FuncUnwinders::GetPersonalityRoutinePtrAddress(Target &target) {
Address personality_addr;
std::shared_ptr<const UnwindPlan> unwind_plan_sp =
GetEHFrameUnwindPlan(target);
if (unwind_plan_sp.get() == nullptr) {
unwind_plan_sp = GetCompactUnwindUnwindPlan(target);
}
if (unwind_plan_sp.get() == nullptr) {
unwind_plan_sp = GetObjectFileUnwindPlan(target);
}
if (unwind_plan_sp.get() &&
unwind_plan_sp->GetPersonalityFunctionPtr().IsValid()) {
personality_addr = unwind_plan_sp->GetPersonalityFunctionPtr();
}
return personality_addr;
}

13
lldb/source/Symbol/UnwindPlan.cpp
View File

@@ -511,19 +511,6 @@ void UnwindPlan::Dump(Stream &s, Thread *thread, lldb::addr_t base_addr) const {
s.Printf("This UnwindPlan originally sourced from %s\n",
m_source_name.GetCString());
}
if (m_lsda_address.IsValid() && m_personality_func_addr.IsValid()) {
TargetSP target_sp(thread->CalculateTarget());
addr_t lsda_load_addr = m_lsda_address.GetLoadAddress(target_sp.get());
addr_t personality_func_load_addr =
m_personality_func_addr.GetLoadAddress(target_sp.get());
if (lsda_load_addr != LLDB_INVALID_ADDRESS &&
personality_func_load_addr != LLDB_INVALID_ADDRESS) {
s.Printf("LSDA address 0x%" PRIx64
", personality routine is at address 0x%" PRIx64 "\n",
lsda_load_addr, personality_func_load_addr);
}
}
s.Printf("This UnwindPlan is sourced from the compiler: ");
switch (m_plan_is_sourced_from_compiler) {
case eLazyBoolYes: