Report an error for an unknown -z option.

[ruiu]

Summary

This is a less clever version of https://reviews.llvm.org/D48433.
This is a dumb version but I think I prefer this for its simplicity.

[grimar]

Well, if you're OK with such straightforward approach, I have no objections either. Its indeed simplest way probably. LGTM.

[ruiu]

The problem of doing an error check this way is, when it is easy to make the list inconsistent you remove an -z option support. However, that's not a real concern because we can't remove any -z option once it is implemented and released. So this simple way should suffice.

[grimar]

In D48621#1144498, @ruiu wrote:

The problem of doing an error check this way is, when it is easy to make the list inconsistent you remove an -z option support. However, that's not a real concern because we can't remove any -z option once it is implemented and released. So this simple way should suffice.

Yeah, speaking honestly my approach felt a bit tricky to me. But I was not sure that dumb way (which is first that comes to mind) is acceptable either. I think I am happy with it.

lld/ELF/Driver.cpp

for (auto *Arg : Args.filtered_reverse(OPT_z)) {
     if (K1 == Arg->getValue())
       return true;
     if (K2 == Arg->getValue())
       return false;
   }
   return Default;
 }
 
+static bool isKnown(StringRef S) {
+  return S == "combreloc" || S == "copyreloc" || S == "defs" ||
+      S == "execstack" || S == "hazardplt" || S == "initfirst" ||
+      S == "keep-text-section-prefix" || S == "lazy" || S == "muldefs" ||
+      S == "nocombreloc" || S == "nocopyreloc" || S == "nodelete" ||
+      S == "nodlopen" || S == "noexecstack" ||
+      S == "nokeep-text-section-prefix" || S == "norelro" || S == "notext" ||
+      S == "now" || S == "origin" || S == "relro" || S == "retpolineplt" ||
+      S == "rodynamic" || S == "text" || S == "wxneeded" ||
+      S.startswith("max-page-size") || S.startswith("stack-size");
+}
+
+// Report an error for an unknown -z option.
+static void checkZOptions(opt::InputArgList &Args) {
+  for (auto *Arg : Args.filtered(OPT_z))
+    if (!isKnown(Arg->getValue()))
+      error("unknown -z value: " + StringRef(Arg->getValue()));
+}
+
 void LinkerDriver::main(ArrayRef<const char *> ArgsArr) {
   ELFOptTable Parser;
   opt::InputArgList Args = Parser.parse(ArgsArr.slice(1));
 
   // Interpret this flag early because error() depends on them.
   errorHandler().ErrorLimit = args::getInteger(Args, OPT_error_limit, 20);
 
   // Handle -help
if (ErrOrWriter) {
       make<std::unique_ptr<TarWriter>>(std::move(*ErrOrWriter));
     } else {
       error(Twine("--reproduce: failed to open ") + Path + ": " +
             toString(ErrOrWriter.takeError()));
     }
   }
 
   readConfigs(Args);
+  checkZOptions(Args);
   initLLVM();
   createFiles(Args);
   if (errorCount())
     return;
 
   inferMachineType();
   setConfigs(Args);
   checkOptions(Args);

lld/test/ELF/driver.test

 ## "--output=foo" is equivalent to "-o foo".
 # RUN: not ld.lld %t --output=/no/such/file 2>&1 | FileCheck -check-prefix=ERR7 %s
 # ERR7: cannot open output file /no/such/file
 
 ## "-output=foo" is equivalent to "-o utput=foo".
 # RUN: not ld.lld %t -output=/no/such/file 2>&1 | FileCheck -check-prefix=ERR8 %s
 # ERR8: cannot open output file utput=/no/such/file
 
+# RUN: not ld.lld %t -z foo 2>&1 | FileCheck -check-prefix=ERR9 %s
+# ERR9: unknown -z value: foo
+
 .globl _start
 _start:
   nop