[LLD][COFF] Cleanup error messages / add more coverage tests

- Log the reason for a PDB or precompiled-OBJ load failure
- Properly handle out-of-date PDB or precompiled-OBJ signature by displaying a corresponding error
- Slightly change behavior on PDB failure: any subsequent load attempt from another OBJ would result in the same error message being logged
- Slightly change behavior on PDB failure: retry with filename only if previous error was ENOENT ("no such file or directory")
- Tests: a. for native PDB errors; b. cover all the cases above

Differential Revision: https://reviews.llvm.org/D51559

llvm-svn: 341825

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/DebugInfo/PDB/GenericError.cpp b/llvm/lib/DebugInfo/PDB/GenericError.cpp
index b6e668a..95f6c15 100644
--- a/llvm/lib/DebugInfo/PDB/GenericError.cpp
+++ b/llvm/lib/DebugInfo/PDB/GenericError.cpp
@@ -35,7 +35,7 @@ public:
     case pdb_error_code::invalid_utf8_path:
       return "The PDB file path is an invalid UTF8 sequence.";
     case pdb_error_code::signature_out_of_date:
-      return "The signature does not match; the file(s) might be out of date";
+      return "The signature does not match; the file(s) might be out of date.";
     }
     llvm_unreachable("Unrecognized generic_error_code");
   }