<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, 8 insertions, 14 deletions

diff --git a/lldb/source/Core/ModuleChild.cpp b/lldb/source/Core/ModuleChild.cpp
index f38fb4f6c36..9637fc3aedd 100644
--- a/lldb/source/Core/ModuleChild.cpp
+++ b/lldb/source/Core/ModuleChild.cpp
@@ -11,13 +11,13 @@
 
 using namespace lldb_private;
 
-ModuleChild::ModuleChild (Module* module) :
-    m_module(module)
+ModuleChild::ModuleChild (const lldb::ModuleSP &module_sp) :
+    m_module_wp (module_sp)
 {
 }
 
 ModuleChild::ModuleChild (const ModuleChild& rhs) :
-    m_module(rhs.m_module)
+    m_module_wp(rhs.m_module_wp)
 {
 }
 
@@ -29,24 +29,18 @@ const ModuleChild&
 ModuleChild::operator= (const ModuleChild& rhs)
 {
     if (this != &rhs)
-        m_module = rhs.m_module;
+        m_module_wp = rhs.m_module_wp;
     return *this;
 }
 
-Module *
-ModuleChild::GetModule ()
-{
-    return m_module;
-}
-
-Module *
+lldb::ModuleSP
 ModuleChild::GetModule () const
 {
-    return m_module;
+    return m_module_wp.lock();
 }
 
 void
-ModuleChild::SetModule (Module *module)
+ModuleChild::SetModule (const lldb::ModuleSP &module_sp)
 {
-    m_module = module;
+    m_module_wp = module_sp;
 }