ArchSpec: fix unintentional promotion of unspecified unknowns to specified unknowns

* ArchSpec::MergeFrom() would erroneously promote an unspecified
  unknown to a specified unknown when both the ArchSpec and the merged
  in ArchSpec were both unspecified unknowns. This no longer happens,
  which fixes issues with global module cache lookup in some
  situations.

* Added ArchSpec::DumpTriple(Stream&) that now properly prints
  unspecified unknowns as '*' and specified unknows as 'unknown'.
  This makes it trivial to tell the difference between the two.
  Converted printing code over ot using DumpTriple() rather than
  building from scratch.

* Fixed up a couple places that were not guaranteeing that an
  unspecified unknown was recorded as such.

llvm-svn: 250253

1 files changed, 6 insertions, 0 deletions

diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index f9f035878c4..0884a1c8ff2 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -1605,6 +1605,12 @@ ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
                 }
             }
 
+            // Make any unknown triple components to be unspecified unknowns.
+            if (arch_spec.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
+                arch_spec.GetTriple().setVendorName (llvm::StringRef());
+            if (arch_spec.GetTriple().getOS() == llvm::Triple::UnknownOS)
+                arch_spec.GetTriple().setOSName (llvm::StringRef());
+
             return section_headers.size();
         }
     }