[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: 331859
diff --git a/llvm/lib/Object/COFFImportFile.cpp b/llvm/lib/Object/COFFImportFile.cpp
index c249a6d..4bde1db 100644
--- a/llvm/lib/Object/COFFImportFile.cpp
+++ b/llvm/lib/Object/COFFImportFile.cpp
@@ -566,8 +566,7 @@
Error writeImportLibrary(StringRef ImportName, StringRef Path,
ArrayRef<COFFShortExport> Exports,
- MachineTypes Machine, bool MakeWeakAliases,
- bool MinGW) {
+ MachineTypes Machine, bool MinGW) {
std::vector<NewArchiveMember> Members;
ObjectFactory OF(llvm::sys::path::filename(ImportName), Machine);
@@ -585,12 +584,6 @@
if (E.Private)
continue;
- if (E.isWeak() && MakeWeakAliases) {
- Members.push_back(OF.createWeakExternal(E.Name, E.ExtName, false));
- Members.push_back(OF.createWeakExternal(E.Name, E.ExtName, true));
- continue;
- }
-
ImportType ImportType = IMPORT_CODE;
if (E.Data)
ImportType = IMPORT_DATA;
@@ -606,6 +599,12 @@
if (!Name)
return Name.takeError();
+ if (!E.AliasTarget.empty() && *Name != E.AliasTarget) {
+ Members.push_back(OF.createWeakExternal(E.AliasTarget, *Name, false));
+ Members.push_back(OF.createWeakExternal(E.AliasTarget, *Name, true));
+ continue;
+ }
+
Members.push_back(
OF.createShortImport(*Name, E.Ordinal, ImportType, NameType));
}
diff --git a/llvm/lib/Object/COFFModuleDefinition.cpp b/llvm/lib/Object/COFFModuleDefinition.cpp
index a571354..c703071 100644
--- a/llvm/lib/Object/COFFModuleDefinition.cpp
+++ b/llvm/lib/Object/COFFModuleDefinition.cpp
@@ -37,6 +37,7 @@
Identifier,
Comma,
Equal,
+ EqualEqual,
KwBase,
KwConstant,
KwData,
@@ -104,9 +105,10 @@
}
case '=':
Buf = Buf.drop_front();
- // GNU dlltool accepts both = and ==.
- if (Buf.startswith("="))
+ if (Buf.startswith("=")) {
Buf = Buf.drop_front();
+ return Token(EqualEqual, "==");
+ }
return Token(Equal, "=");
case ',':
Buf = Buf.drop_front();
@@ -282,6 +284,13 @@
E.Private = true;
continue;
}
+ if (Tok.K == EqualEqual) {
+ read();
+ E.AliasTarget = Tok.Value;
+ if (Machine == IMAGE_FILE_MACHINE_I386 && !isDecorated(E.AliasTarget, MingwDef))
+ E.AliasTarget = std::string("_").append(E.AliasTarget);
+ continue;
+ }
unget();
Info.Exports.push_back(E);
return Error::success();