[COFF] Skip exporting artificial symbols when exporting all symbols

Differential Revision: https://reviews.llvm.org/D51457

llvm-svn: 341017

lld/COFF/MinGW.cpp

@@ -102,8 +102,9 @@ bool AutoExporter::shouldExport(Defined *Sym) const {
     return false;
 
   // Don't export anything that looks like an import symbol (which also can be
-  // a manually defined data symbol with such a name).
-  if (Sym->getName().startswith("__imp_"))
+  // a manually defined data symbol with such a name); don't export artificial
+  // symbols like .refptr pointer stubs.
+  if (Sym->getName().startswith("__imp_") || Sym->getName().startswith("."))
     return false;
 
   // If a corresponding __imp_ symbol exists and is defined, don't export it.

lld/test/COFF/export-all.s

@@ -21,6 +21,7 @@
 .global _dataSym
 .global _unexported
 .global __imp__unexported
+.global .refptr._foobar
 .text
 _DllMainCRTStartup@12:
   ret
@@ -33,6 +34,8 @@ _dataSym:
   .int 4
 __imp__unexported:
   .int _unexported
+.refptr._foobar:
+  .int _foobar
 
 # Test specifying -export-all-symbols, on an object file that contains
 # dllexport directive for some of the symbols.