Make joined instances of JoinedOrSeparate flags point to the unaliased args, like all other arg types do

[thakis]

Summary

This fixes an 8-year-old regression. r105763 made it so that aliases always refer to the unaliased option – but it missed the "joined" branch of JoinedOrSeparate flags. (r162231 then made the Args classes non-virtual, and r169344 moved them from clang to llvm.)

Back then, there was no JoinedOrSeparate flag that was an alias, so it wasn't observable. Now /U in CLCompatOptions is a JoinedOrSeparate alias in clang, and warn_slash_u_filename incorrectly used the aliased arg id (using the unaliased one isn't really a regression since that warning checks if the undefined macro contains slash or backslash and only then emits the warning – and no valid use will pass "-Ufoo/bar" or similar).

Also, lld has many JoinedOrSeparate aliases, and due to this bug it had to explicitly call getUnaliasedOption() in a bunch of places, even though that shouldn't be necessary by design. After this fix in Option, these calls really don't have an effect any more, so remove them.

No intended behavior change.

(I accidentally fixed this bug while working on PR29106 but then wondered why the warn_slash_u_filename broke. When I figured it out, I thought it would make sense to land this in a separate commit.)

[thakis]

ruiu: ping

[ruiu]

LGTM

cfe/trunk/lib/Driver/Driver.cpp

if (A->getOption().getKind() == Option::InputClass) {
 
       // Follow gcc behavior and treat as linker input for invalid -x
       // options. Its not clear why we shouldn't just revert to unknown; but
       // this isn't very important, we might as well be bug compatible.
       if (!InputType) {
         Diag(clang::diag::err_drv_unknown_language) << A->getValue();
         InputType = types::TY_Object;
       }
-    } else if (A->getOption().getID() == options::OPT__SLASH_U) {
+    } else if (A->getOption().getID() == options::OPT_U) {
       assert(A->getNumValues() == 1 && "The /U option has one value.");
       StringRef Val = A->getValue(0);
       if (Val.find_first_of("/\\") != StringRef::npos) {
         // Warn about e.g. "/Users/me/myfile.c".
         Diag(diag::warn_slash_u_filename) << Val;
         Diag(diag::note_use_dashdash);
       }
     }

lld/trunk/COFF/Driver.cpp

if (Config->Machine == I386 && Config->MinGW) {
       if (!Exp.ExtName.empty() && !isDecorated(Exp.ExtName))
         Exp.ExtName = Saver.save("_" + Exp.ExtName);
     }
     Exp.Directives = true;
     Config->Exports.push_back(Exp);
   }
 
   for (auto *Arg : Args) {
-    switch (Arg->getOption().getUnaliasedOption().getID()) {
+    switch (Arg->getOption().getID()) {
     case OPT_aligncomm:
       parseAligncomm(Arg->getValue());
       break;
     case OPT_alternatename:
       parseAlternateName(Arg->getValue());
       break;
     case OPT_defaultlib:
       if (Optional<StringRef> Path = findLib(Arg->getValue()))

lld/trunk/ELF/Driver.cpp

 }
 
 void LinkerDriver::createFiles(opt::InputArgList &Args) {
   // For --{push,pop}-state.
   std::vector<std::tuple<bool, bool, bool>> Stack;
 
   // Iterate over argv to process input files and positional arguments.
   for (auto *Arg : Args) {
-    switch (Arg->getOption().getUnaliasedOption().getID()) {
+    switch (Arg->getOption().getID()) {
     case OPT_library:
       addLibrary(Arg->getValue());
       break;
     case OPT_INPUT:
       addFile(Arg->getValue(), /*WithLOption=*/false);
       break;
     case OPT_defsym: {
       StringRef From;

lld/trunk/ELF/DriverUtils.cpp

 // the same command with the same inputs. This is for --reproduce.
 std::string elf::createResponseFile(const opt::InputArgList &Args) {
   SmallString<0> Data;
   raw_svector_ostream OS(Data);
   OS << "--chroot .\n";
 
   // Copy the command line to the output while rewriting paths.
   for (auto *Arg : Args) {
-    switch (Arg->getOption().getUnaliasedOption().getID()) {
+    switch (Arg->getOption().getID()) {
     case OPT_reproduce:
       break;
     case OPT_INPUT:
       OS << quote(rewritePath(Arg->getValue())) << "\n";
       break;
     case OPT_o:
       // If -o path contains directories, "lld @response.txt" will likely
       // fail because the archive we are creating doesn't contain empty

lld/trunk/MinGW/Driver.cpp

bool mingw::link(ArrayRef<const char *> ArgsArr, raw_ostream &Diag) {
   for (auto *A : Args.filtered(OPT_L)) {
     SearchPaths.push_back(A->getValue());
     Add("-libpath:" + StringRef(A->getValue()));
   }
 
   StringRef Prefix = "";
   bool Static = false;
   for (auto *A : Args) {
-    switch (A->getOption().getUnaliasedOption().getID()) {
+    switch (A->getOption().getID()) {
     case OPT_INPUT:
       if (StringRef(A->getValue()).endswith_lower(".def"))
         Add("-def:" + StringRef(A->getValue()));
       else
         Add(Prefix + StringRef(A->getValue()));
       break;
     case OPT_l:
       Add(Prefix + searchLibrary(A->getValue(), SearchPaths, Static));

lld/trunk/wasm/Driver.cpp

for (StringRef Dir : Config->SearchPaths) {
     }
   }
 
   error("unable to find library -l" + Name);
 }
 
 void LinkerDriver::createFiles(opt::InputArgList &Args) {
   for (auto *Arg : Args) {
-    switch (Arg->getOption().getUnaliasedOption().getID()) {
+    switch (Arg->getOption().getID()) {
     case OPT_l:
       addLibrary(Arg->getValue());
       break;
     case OPT_INPUT:
       addFile(Arg->getValue());
       break;
     case OPT_whole_archive:
       InWholeArchive = true;

 // Reconstructs command line arguments so that so that you can re-run
 // the same command with the same inputs. This is for --reproduce.
 static std::string createResponseFile(const opt::InputArgList &Args) {
   SmallString<0> Data;
   raw_svector_ostream OS(Data);
 
   // Copy the command line to the output while rewriting paths.
   for (auto *Arg : Args) {
-    switch (Arg->getOption().getUnaliasedOption().getID()) {
+    switch (Arg->getOption().getID()) {
     case OPT_reproduce:
       break;
     case OPT_INPUT:
       OS << quote(relativeToRoot(Arg->getValue())) << "\n";
       break;
     case OPT_o:
       // If -o path contains directories, "lld @response.txt" will likely
       // fail because the archive we are creating doesn't contain empty

llvm/trunk/lib/Option/Option.cpp

for (unsigned i = 1; i != getNumArgs(); ++i)
       A->getValues().push_back(Args.getArgString(Index - getNumArgs() + i));
     return A;
   }
   case JoinedOrSeparateClass: {
     // If this is not an exact match, it is a joined arg.
     // FIXME: Avoid strlen.
     if (ArgSize != strlen(Args.getArgString(Index))) {
       const char *Value = Args.getArgString(Index) + ArgSize;
-      return new Arg(*this, Spelling, Index++, Value);
+      return new Arg(UnaliasedOption, Spelling, Index++, Value);
     }
 
     // Otherwise it must be separate.
     Index += 2;
     if (Index > Args.getNumInputArgStrings() ||
         Args.getArgString(Index - 1) == nullptr)
       return nullptr;