Added a new plug-in type: lldb_private::OperatingSystem. The operating system

plug-ins are add on plug-ins for the lldb_private::Process class that can add
thread contexts that are read from memory. It is common in kernels to have
a lot of threads that are not currently executing on any cores (JTAG debugging
also follows this sort of thing) and are context switched out whose state is
stored in memory data structures. Clients can now subclass the OperatingSystem
plug-ins and then make sure their Create functions correcltly only enable 
themselves when the right binary/target triple are being debugged. The 
operating system plug-ins get a chance to attach themselves to processes just
after launching or attaching and are given a lldb_private::Process object 
pointer which can be inspected to see if the main executable, target triple,
or any shared  libraries match a case where the OS plug-in should be used.
Currently the OS plug-ins can create new threads, define the register contexts
for these threads (which can all be different if desired), and populate and
manage the thread info (stop reason, registers in the register context) as
the debug session goes on.

llvm-svn: 138228

1 files changed, 3 insertions, 1 deletions

diff --git a/lldb/source/Core/Section.cpp b/lldb/source/Core/Section.cpp
index f32c72bdba4..60b3e15fccb 100644
--- a/lldb/source/Core/Section.cpp
+++ b/lldb/source/Core/Section.cpp
@@ -117,7 +117,9 @@ Section::GetLoadBaseAddress (Target *target) const
     addr_t load_base_addr = LLDB_INVALID_ADDRESS;
     if (m_linked_section)
     {
-        load_base_addr = m_linked_section->GetLoadBaseAddress(target) + m_linked_offset;
+        load_base_addr = m_linked_section->GetLoadBaseAddress(target);
+        if (load_base_addr != LLDB_INVALID_ADDRESS)
+            load_base_addr += m_linked_offset;
     }
     else
     if (m_parent)