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Fix the partial backtrace when using a combination of stripped function symbols 

and -fomit-frame-pointer.

- Parses eh_frame FDEs to determine the function address and size so that
the call frame parsing can continue.

Note: This code path is specific to ELF and PECOFF, because ObjectFileMachO
uses LCT_FunctionStarts to efficiently populate the symbol table.

Thanks to Jason Molenda for the review!

llvm-svn: 186585
This commit is contained in:
Ashok Thirumurthi 2013-07-18 15:05:56 +00:00
parent f90ccb082b
commit 044c36a21c
2 changed files with 26 additions and 16 deletions
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36
lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
View File

@ -17,6 +17,7 @@
#include "lldb/Core/RegisterValue.h"
#include "lldb/Core/Value.h"
#include "lldb/Expression/DWARFExpression.h"
#include "lldb/Symbol/DWARFCallFrameInfo.h"
#include "lldb/Symbol/FuncUnwinders.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/ObjectFile.h"
@ -201,17 +202,14 @@ RegisterContextLLDB::InitializeZerothFrame()
}
addr_t cfa_regval;
addr_t cfa_regval = LLDB_INVALID_ADDRESS;
if (!ReadGPRValue (row_register_kind, active_row->GetCFARegister(), cfa_regval))
{
m_frame_type = eNotAValidFrame;
return;
}
else
{
}
cfa_offset = active_row->GetCFAOffset ();
cfa_offset = active_row->GetCFAOffset ();
m_cfa = cfa_regval + cfa_offset;
UnwindLogMsg ("cfa_regval = 0x%16.16" PRIx64 " (cfa_regval = 0x%16.16" PRIx64 ", cfa_offset = %i)", m_cfa, cfa_regval, cfa_offset);
@ -322,7 +320,7 @@ RegisterContextLLDB::InitializeNonZerothFrame()
m_all_registers_available = false;
m_current_offset = -1;
m_current_offset_backed_up_one = -1;
addr_t cfa_regval;
addr_t cfa_regval = LLDB_INVALID_ADDRESS;
int row_register_kind = m_full_unwind_plan_sp->GetRegisterKind ();
UnwindPlan::RowSP row = m_full_unwind_plan_sp->GetRowForFunctionOffset(0);
if (row.get())
@ -429,7 +427,11 @@ RegisterContextLLDB::InitializeNonZerothFrame()
m_current_offset = m_current_pc.GetOffset() - m_start_pc.GetOffset();
m_current_offset_backed_up_one = m_current_offset;
if (decr_pc_and_recompute_addr_range && m_current_offset_backed_up_one > 0)
{
m_current_offset_backed_up_one--;
if (m_sym_ctx_valid)
m_current_pc.SetOffset(m_current_pc.GetOffset() - 1);
}
}
else
{
@ -496,15 +498,15 @@ RegisterContextLLDB::InitializeNonZerothFrame()
return;
}
addr_t cfa_regval;
addr_t cfa_regval = LLDB_INVALID_ADDRESS;
if (!ReadGPRValue (row_register_kind, active_row->GetCFARegister(), cfa_regval))
{
UnwindLogMsg ("failed to get cfa reg %d/%d", row_register_kind, active_row->GetCFARegister());
m_frame_type = eNotAValidFrame;
return;
}
cfa_offset = active_row->GetCFAOffset ();
cfa_offset = active_row->GetCFAOffset ();
m_cfa = cfa_regval + cfa_offset;
UnwindLogMsg ("cfa_regval = 0x%16.16" PRIx64 " (cfa_regval = 0x%16.16" PRIx64 ", cfa_offset = %i)", m_cfa, cfa_regval, cfa_offset);
@ -677,10 +679,24 @@ RegisterContextLLDB::GetFullUnwindPlanForFrame ()
func_unwinders_sp = pc_module_sp->GetObjectFile()->GetUnwindTable().GetFuncUnwindersContainingAddress (m_current_pc, m_sym_ctx);
}
// No FuncUnwinders available for this pc, try using architectural default unwind.
// No FuncUnwinders available for this pc (i.e. a stripped function symbol and -fomit-frame-pointer).
// Try using the eh_frame information relative to the current PC,
// and finally fall back on the architectural default unwind.
if (!func_unwinders_sp)
{
DWARFCallFrameInfo *eh_frame = pc_module_sp && pc_module_sp->GetObjectFile() ?
pc_module_sp->GetObjectFile()->GetUnwindTable().GetEHFrameInfo() : nullptr;
m_frame_type = eNormalFrame;
if (eh_frame && m_current_pc.IsValid())
{
unwind_plan_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric));
// Even with -fomit-frame-pointer, we can try eh_frame to get back on track.
if (eh_frame->GetUnwindPlan (m_current_pc, *unwind_plan_sp))
return unwind_plan_sp;
else
unwind_plan_sp.reset();
}
return arch_default_unwind_plan_sp;
}
@ -1249,7 +1265,7 @@ RegisterContextLLDB::InvalidateFullUnwindPlan ()
}
m_registers.clear();
m_full_unwind_plan_sp = arch_default_unwind_plan_sp;
addr_t cfa_regval;
addr_t cfa_regval = LLDB_INVALID_ADDRESS;
if (ReadGPRValue (arch_default_unwind_plan_sp->GetRegisterKind(), active_row->GetCFARegister(), cfa_regval))
{
m_cfa = cfa_regval + active_row->GetCFAOffset ();

6
lldb/test/functionalities/inferior-assert/TestInferiorAssert.py
View File

@ -15,8 +15,6 @@ class AssertingInferiorTestCase(TestBase):
self.buildDsym()
self.inferior_asserting()
@skipIfGcc # avoid an xpass on the buildbots where libc was not built with -fomit-frame-pointer
@expectedFailureLinux # llvm.org/pr15671 - backtrace does not include the assert site
def test_inferior_asserting_dwarf(self):
"""Test that lldb reliably catches the inferior asserting (command)."""
self.buildDwarf()
@ -45,8 +43,6 @@ class AssertingInferiorTestCase(TestBase):
self.buildDsym()
self.inferior_asserting_expr()
@skipIfGcc # avoid an xpass on the buildbots where libc was not built with -fomit-frame-pointer
@expectedFailureLinux # llvm.org/pr15671 - backtrace does not include the assert site
def test_inferior_asserting_expr(self):
"""Test that the lldb expression interpreter can read from the inferior after asserting (command)."""
self.buildDwarf()
@ -58,8 +54,6 @@ class AssertingInferiorTestCase(TestBase):
self.buildDsym()
self.inferior_asserting_step()
@skipIfGcc # avoid an xpass on the buildbots where libc was not built with -fomit-frame-pointer
@expectedFailureLinux # llvm.org/pr15671 - backtrace does not include the assert site
def test_inferior_asserting_step(self):
"""Test that lldb functions correctly after stepping through a call to assert()."""
self.buildDwarf()