[llvm] r374442 - [PDB] Fix bug when using multiple PCH header objects with the same name.

[Zachary Turner via llvm-commits]

Author: zturner
Date: Thu Oct 10 13:25:51 2019
New Revision: 374442

URL: http://llvm.org/viewvc/llvm-project?rev=374442&view=rev
Log:
[PDB] Fix bug when using multiple PCH header objects with the same name.

A common pattern in Windows is to have all your precompiled headers
use an object named stdafx.obj.  If you've got a project with many
different static libs, you might use a separate PCH for each one of
these.

During the final link step, a file from A might reference the PCH
object from A, but it will have the same name (stdafx.obj) as any
other PCH from another project.  The only difference will be the
path.  For example, A might be A/stdafx.obj while B is B/stdafx.obj.

The existing algorithm checks only the filename that was passed on
the command line (or stored in archive), but this is insufficient in
the case where relative paths are used, because depending on the
command line object file / library order, it might find the wrong
PCH object first resulting in a signature mismatch.

The fix here is to simply check whether the absolute path of the
PCH object (which is stored in the input obj file for the file that
references the PCH) *ends with* the full relative path of whatever
is specified on the command line (or is in the archive).

Differential Revision: https://reviews.llvm.org/D66431

Modified:
    llvm/trunk/include/llvm/DebugInfo/PDB/GenericError.h
    llvm/trunk/lib/DebugInfo/PDB/GenericError.cpp

Modified: llvm/trunk/include/llvm/DebugInfo/PDB/GenericError.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/PDB/GenericError.h?rev=374442&r1=374441&r2=374442&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/PDB/GenericError.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/PDB/GenericError.h Thu Oct 10 13:25:51 2019
@@ -20,7 +20,7 @@ enum class pdb_error_code {
   dia_sdk_not_present,
   dia_failed_loading,
   signature_out_of_date,
-  external_cmdline_ref,
+  no_matching_pch,
   unspecified,
 };
 } // namespace pdb

Modified: llvm/trunk/lib/DebugInfo/PDB/GenericError.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/PDB/GenericError.cpp?rev=374442&r1=374441&r2=374442&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/PDB/GenericError.cpp (original)
+++ llvm/trunk/lib/DebugInfo/PDB/GenericError.cpp Thu Oct 10 13:25:51 2019
@@ -34,8 +34,8 @@ public:
       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.";
-    case pdb_error_code::external_cmdline_ref:
-      return "The path to this file must be provided on the command-line.";
+    case pdb_error_code::no_matching_pch:
+      return "No matching precompiled header could be located.";
     }
     llvm_unreachable("Unrecognized generic_error_code");
   }