[COFF] Improve correctness of def parsing for GNU features

The operator == used for exporting a function with a different
name in the DLL compared to the name in the import library
(which is useful for adding linker level aliases for function
in the import library) is a feature distinct and different from
the operator = used for exporting a function with a different
name (both in import library and DLL) than in the implementation
producing the DLL.

When creating an import library using dlltool, from a def file that
contains forwards (Func = OtherDll.Func), this shouldn't affect the
produced import library, which should still behave just as if it
was a normal exported function.

This clears a lot of confusion and subtle misunderstandings, and
avoids a parameter that was used to avoid creating weak aliases
when invoked from lld. (This parameter was added previously due to
the existing conflation of the two features.)

Differential Revision: https://reviews.llvm.org/D46245

llvm-svn: 331860

1 files changed, 4 insertions, 5 deletions

diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index 0f9ba79b8dd..c4636c2e262 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -559,7 +559,7 @@ static void createImportLibrary(bool AsLib) {
 
   if (!Config->Incremental) {
     HandleError(writeImportLibrary(LibName, Path, Exports, Config->Machine,
-                                   false, Config->MinGW));
+                                   Config->MinGW));
     return;
   }
 
@@ -569,7 +569,7 @@ static void createImportLibrary(bool AsLib) {
       Path, /*FileSize*/ -1, /*RequiresNullTerminator*/ false);
   if (!OldBuf) {
     HandleError(writeImportLibrary(LibName, Path, Exports, Config->Machine,
-                                   false, Config->MinGW));
+                                   Config->MinGW));
     return;
   }
 
@@ -580,7 +580,7 @@ static void createImportLibrary(bool AsLib) {
           EC.message());
 
   if (Error E = writeImportLibrary(LibName, TmpName, Exports, Config->Machine,
-                                   false, Config->MinGW)) {
+                                   Config->MinGW)) {
     HandleError(std::move(E));
     return;
   }
@@ -626,8 +626,7 @@ static void parseModuleDefs(StringRef Path) {
   for (COFFShortExport E1 : M.Exports) {
     Export E2;
     E2.Name = Saver.save(E1.Name);
-    if (E1.isWeak())
-      E2.ExtName = Saver.save(E1.ExtName);
+    E2.ExtName = Saver.save(E1.ExtName);
     E2.Ordinal = E1.Ordinal;
     E2.Noname = E1.Noname;
     E2.Data = E1.Data;