[Lldb-commits] [lldb] r139760 - in /lldb/trunk: include/lldb/Symbol/FuncUnwinders.h source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp source/Plugins/ABI/MacOSX-i386/ABIMacOSX_i386.cpp source/Plugins/ABI/SysV-x86_64/ABISysV_x86_64.cpp source/Plugins/Process/Utility/RegisterContextLLDB.cpp source/Symbol/FuncUnwinders.cpp
Jason Molenda
jmolenda at apple.com
Wed Sep 14 17:44:34 PDT 2011
Author: jmolenda
Date: Wed Sep 14 19:44:34 2011
New Revision: 139760
URL: http://llvm.org/viewvc/llvm-project?rev=139760&view=rev
Log:
Have the FuncUnwinder object request & provide an architecture-defined
UnwindPlan for unwinding from the first instruction of an otherwise
unknown function call (GetUnwindPlanArchitectureDefaultAtFunctionEntry()).
Update RegisterContextLLDB::GetFullUnwindPlanForFrame() to detect the
case of a frame 0 at address 0x0 which indicates that we jumped through
a NULL function pointer. Use the ABI's FunctionEntryUnwindPlan to
find the caller frame.
These changes make it so lldb can identify the calling frame correctly
in code like
int main ()
{
void (*f)(void) = 0;
f();
}
Modified:
lldb/trunk/include/lldb/Symbol/FuncUnwinders.h
lldb/trunk/source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp
lldb/trunk/source/Plugins/ABI/MacOSX-i386/ABIMacOSX_i386.cpp
lldb/trunk/source/Plugins/ABI/SysV-x86_64/ABISysV_x86_64.cpp
lldb/trunk/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
lldb/trunk/source/Symbol/FuncUnwinders.cpp
Modified: lldb/trunk/include/lldb/Symbol/FuncUnwinders.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/include/lldb/Symbol/FuncUnwinders.h?rev=139760&r1=139759&r2=139760&view=diff
==============================================================================
--- lldb/trunk/include/lldb/Symbol/FuncUnwinders.h (original)
+++ lldb/trunk/include/lldb/Symbol/FuncUnwinders.h Wed Sep 14 19:44:34 2011
@@ -55,6 +55,9 @@
lldb::UnwindPlanSP
GetUnwindPlanArchitectureDefault (lldb_private::Thread& thread);
+ lldb::UnwindPlanSP
+ GetUnwindPlanArchitectureDefaultAtFunctionEntry (lldb_private::Thread& thread);
+
Address&
GetFirstNonPrologueInsn (Target& target);
@@ -78,11 +81,14 @@
lldb::UnwindPlanSP m_unwind_plan_non_call_site_sp;
lldb::UnwindPlanSP m_unwind_plan_fast_sp;
lldb::UnwindPlanSP m_unwind_plan_arch_default_sp;
+ lldb::UnwindPlanSP m_unwind_plan_arch_default_at_func_entry_sp;
bool m_tried_unwind_at_call_site:1,
m_tried_unwind_at_non_call_site:1,
m_tried_unwind_fast:1,
- m_tried_unwind_arch_default:1;
+ m_tried_unwind_arch_default:1,
+ m_tried_unwind_arch_default_at_func_entry:1;
+
Address m_first_non_prologue_insn;
Modified: lldb/trunk/source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp?rev=139760&r1=139759&r2=139760&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp (original)
+++ lldb/trunk/source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp Wed Sep 14 19:44:34 2011
@@ -538,7 +538,7 @@
// All other registers are the same.
- unwind_plan.SetSourceName (pluginName);
+ unwind_plan.SetSourceName ("arm at-func-entry default");
return true;
}
Modified: lldb/trunk/source/Plugins/ABI/MacOSX-i386/ABIMacOSX_i386.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ABI/MacOSX-i386/ABIMacOSX_i386.cpp?rev=139760&r1=139759&r2=139760&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/ABI/MacOSX-i386/ABIMacOSX_i386.cpp (original)
+++ lldb/trunk/source/Plugins/ABI/MacOSX-i386/ABIMacOSX_i386.cpp Wed Sep 14 19:44:34 2011
@@ -803,7 +803,7 @@
row.SetCFAOffset (4);
row.SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, -4, false);
unwind_plan.AppendRow (row);
- unwind_plan.SetSourceName (pluginName);
+ unwind_plan.SetSourceName ("i386 at-func-entry default");
return true;
}
Modified: lldb/trunk/source/Plugins/ABI/SysV-x86_64/ABISysV_x86_64.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ABI/SysV-x86_64/ABISysV_x86_64.cpp?rev=139760&r1=139759&r2=139760&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/ABI/SysV-x86_64/ABISysV_x86_64.cpp (original)
+++ lldb/trunk/source/Plugins/ABI/SysV-x86_64/ABISysV_x86_64.cpp Wed Sep 14 19:44:34 2011
@@ -661,7 +661,7 @@
row.SetCFAOffset (8);
row.SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, -8, false);
unwind_plan.AppendRow (row);
- unwind_plan.SetSourceName (pluginName);
+ unwind_plan.SetSourceName ("x86_64 at-func-entry default");
return true;
}
Modified: lldb/trunk/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/Utility/RegisterContextLLDB.cpp?rev=139760&r1=139759&r2=139760&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/Utility/RegisterContextLLDB.cpp (original)
+++ lldb/trunk/source/Plugins/Process/Utility/RegisterContextLLDB.cpp Wed Sep 14 19:44:34 2011
@@ -552,7 +552,19 @@
m_all_registers_available = true;
}
- // No Module for the current pc, try using the architecture default unwind.
+ // If we've done a jmp 0x0 / bl 0x0 (called through a null function pointer) so the pc is 0x0
+ // in the zeroth frame, we need to use the "unwind at first instruction" arch default UnwindPlan
+ if (behaves_like_zeroth_frame
+ && m_current_pc.IsValid()
+ && m_current_pc.GetLoadAddress (&m_thread.GetProcess().GetTarget()) == 0)
+ {
+ unwind_plan_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric));
+ abi->CreateFunctionEntryUnwindPlan(*unwind_plan_sp);
+ m_frame_type = eNormalFrame;
+ return unwind_plan_sp;
+ }
+
+ // No Module fm_current_pc.GetLoadAddress (&m_thread.GetProcess().GetTarget()or the current pc, try using the architecture default unwind.
if (!m_current_pc.IsValid() || m_current_pc.GetModule() == NULL || m_current_pc.GetModule()->GetObjectFile() == NULL)
{
m_frame_type = eNormalFrame;
Modified: lldb/trunk/source/Symbol/FuncUnwinders.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Symbol/FuncUnwinders.cpp?rev=139760&r1=139759&r2=139760&view=diff
==============================================================================
--- lldb/trunk/source/Symbol/FuncUnwinders.cpp (original)
+++ lldb/trunk/source/Symbol/FuncUnwinders.cpp Wed Sep 14 19:44:34 2011
@@ -42,6 +42,7 @@
m_tried_unwind_at_non_call_site (false),
m_tried_unwind_fast (false),
m_tried_unwind_arch_default (false),
+ m_tried_unwind_arch_default_at_func_entry (false),
m_first_non_prologue_insn()
{
}
@@ -181,6 +182,43 @@
return m_unwind_plan_arch_default_sp;
}
+UnwindPlanSP
+FuncUnwinders::GetUnwindPlanArchitectureDefaultAtFunctionEntry (Thread& thread)
+{
+ // Lock the mutex to ensure we can always give out the most appropriate
+ // information. We want to make sure if someone requests an unwind
+ // plan, that they get one and don't run into a race condition where one
+ // thread has started to create the unwind plan and has put it into
+ // the auto_ptr member variable, and have another thread enter this function
+ // and return the partially filled pointer contained in the auto_ptr.
+ // We also want to make sure that we lock out other unwind plans from
+ // being accessed until this one is done creating itself in case someone
+ // had some code like:
+ // UnwindPlan *best_unwind_plan = ...GetUnwindPlanAtCallSite (...)
+ // if (best_unwind_plan == NULL)
+ // best_unwind_plan = GetUnwindPlanAtNonCallSite (...)
+ Mutex::Locker locker (m_mutex);
+ if (m_tried_unwind_arch_default_at_func_entry == false && m_unwind_plan_arch_default_at_func_entry_sp.get() == NULL)
+ {
+ m_tried_unwind_arch_default_at_func_entry = true;
+ Address current_pc;
+ Target *target = thread.CalculateTarget();
+ if (target)
+ {
+ ABI *abi = thread.GetProcess().GetABI().get();
+ if (abi)
+ {
+ m_unwind_plan_arch_default_at_func_entry_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric));
+ if (m_unwind_plan_arch_default_at_func_entry_sp)
+ abi->CreateFunctionEntryUnwindPlan(*m_unwind_plan_arch_default_at_func_entry_sp);
+ }
+ }
+ }
+
+ return m_unwind_plan_arch_default_sp;
+}
+
+
Address&
FuncUnwinders::GetFirstNonPrologueInsn (Target& target)
{
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