[PECOFF] Fix exported symbols in an import library.

Looks like if you have symbol foo in a module-definition file
(.def file), and if the actual symbol name to match that export
description is _foo@x (where x is an integer), the exported
symbol name becomes this.

  - foo in the .dll file
  - foo@x in the .lib file

I have checked in a few fixes recently for exported symbol name mangling.
I haven't found a simple rule that governs all the mangling rules.
There may not ever exist. For now, this is a patch to improve .lib
file compatibility.

llvm-svn: 223524

1 files changed, 2 insertions, 0 deletions

diff --git a/lld/lib/ReaderWriter/PECOFF/WriterImportLibrary.cpp b/lld/lib/ReaderWriter/PECOFF/WriterImportLibrary.cpp
index d6081c1cf4b..fd3360f018b 100644
--- a/lld/lib/ReaderWriter/PECOFF/WriterImportLibrary.cpp
+++ b/lld/lib/ReaderWriter/PECOFF/WriterImportLibrary.cpp
@@ -35,6 +35,8 @@ createModuleDefinitionFile(const PECOFFLinkingContext &ctx) {
     os << "  ";
     if (!desc.externalName.empty()) {
       os << desc.externalName;
+    } else if (!desc.mangledName.empty()) {
+      os << ctx.undecorateSymbol(desc.mangledName);
     } else {
       os << ctx.undecorateSymbol(desc.name);
     }