Don't stomp the triple when loading a PECOFF target.

When you create a target, it tries to look for the platform's list
of supported architectures for a match.  The match it finds can
contain specific triples, like i386-pc-windows-msvc.  Later, we
overwrite this value with the most generic triple that can apply
to any platform with COFF support, causing some of the fields of
the triple to get overwritten.

This patch changes the behavior to only merge in values from the COFF
triple if the fields of the matching triple were unknown/unspecified
to begin with.

This fixes load address resolution on Windows, since it enables the
DynamicLoaderWindows to be used instead of DynamicLoaderStatic.

Reviewed by: Greg Clayton
Differential Revision: http://reviews.llvm.org/D7120

llvm-svn: 226849

1 files changed, 7 insertions, 3 deletions

diff --git a/lldb/source/Core/Module.cpp b/lldb/source/Core/Module.cpp
index 900eea2e041..d38d403bd31 100644
--- a/lldb/source/Core/Module.cpp
+++ b/lldb/source/Core/Module.cpp
@@ -1304,10 +1304,14 @@ Module::GetObjectFile()
                                                    data_offset);
             if (m_objfile_sp)
             {
-                // Once we get the object file, update our module with the object file's 
+                // Once we get the object file, update our module with the object file's
                 // architecture since it might differ in vendor/os if some parts were
-                // unknown.
-                m_objfile_sp->GetArchitecture (m_arch);
+                // unknown.  But since the matching arch might already be more specific
+                // than the generic COFF architecture, only merge in those values that
+                // overwrite unspecified unknown values.
+                ArchSpec new_arch;
+                m_objfile_sp->GetArchitecture(new_arch);
+                m_arch.MergeFrom(new_arch);
             }
             else
             {