<rdar://problem/10103468>

I started work on being able to add symbol files after a debug session
had started with a new "target symfile add" command and quickly ran into
problems with stale Address objects in breakpoint locations that had 
lldb_private::Section pointers into modules that had been removed or 
replaced. This also let to grabbing stale modules from those sections. 
So I needed to thread harded the Address, Section and related objects.

To do this I modified the ModuleChild class to now require a ModuleSP
on initialization so that a weak reference can created. I also changed
all places that were handing out "Section *" to have them hand out SectionSP.
All ObjectFile, SymbolFile and SymbolVendors were inheriting from ModuleChild
so all of the find plug-in, static creation function and constructors now
require ModuleSP references instead of Module *. 

Address objects now have weak references to their sections which can
safely go stale when a module gets destructed. 

This checkin doesn't complete the "target symfile add" command, but it
does get us a lot clioser to being able to do such things without a high
risk of crashing or memory corruption.

llvm-svn: 151336

1 files changed, 5 insertions, 7 deletions

diff --git a/lldb/source/Core/ValueObjectVariable.cpp b/lldb/source/Core/ValueObjectVariable.cpp
index 653b3cb58e8..f5c5d0132da 100644
--- a/lldb/source/Core/ValueObjectVariable.cpp
+++ b/lldb/source/Core/ValueObjectVariable.cpp
@@ -180,7 +180,7 @@ ValueObjectVariable::UpdateValue ()
             case Value::eValueTypeScalar:
                 // The variable value is in the Scalar value inside the m_value.
                 // We can point our m_data right to it.
-                m_error = m_value.GetValueAsData (&exe_ctx, GetClangAST(), m_data, 0, GetModule());
+                m_error = m_value.GetValueAsData (&exe_ctx, GetClangAST(), m_data, 0, GetModule().get());
                 break;
 
             case Value::eValueTypeFileAddress:
@@ -233,7 +233,7 @@ ValueObjectVariable::UpdateValue ()
                     // so it can extract read its value into m_data appropriately
                     Value value(m_value);
                     value.SetContext(Value::eContextTypeVariable, variable);
-                    m_error = value.GetValueAsData(&exe_ctx, GetClangAST(), m_data, 0, GetModule());
+                    m_error = value.GetValueAsData(&exe_ctx, GetClangAST(), m_data, 0, GetModule().get());
                 }
                 break;
             }
@@ -272,7 +272,7 @@ ValueObjectVariable::IsInScope ()
          
 }
 
-Module *
+lldb::ModuleSP
 ValueObjectVariable::GetModule()
 {
     if (m_variable_sp)
@@ -280,12 +280,10 @@ ValueObjectVariable::GetModule()
         SymbolContextScope *sc_scope = m_variable_sp->GetSymbolContextScope();
         if (sc_scope)
         {
-            SymbolContext sc;
-            sc_scope->CalculateSymbolContext (&sc);
-            return sc.module_sp.get();
+            return sc_scope->CalculateSymbolContextModule();
         }
     }
-    return NULL;
+    return lldb::ModuleSP();
 }
 
 SymbolContextScope *