[ELF] - Use InitTargetOptionsFromCodeGenFlags/ParseCommandLineOptions for parsing LTO options.

[grimar]

Summary

gold plugin uses InitTargetOptionsFromCodeGenFlags +
ParseCommandLineOptions for parsing LTO options.
Patch do the same change for LLD.

Such change helps to avoid parsing/whitelisting LTO
plugin options again on linker side, what can help LLD
to automatically support new -plugin-opt=xxx options
passed.

[grimar]

LGTMed by Rafael in mail list.

[ruiu]

ELF/Driver.cpp

591

We have Config->Argv, so you don't need to pass Argv0 around.

706–707

I don't think you need this comment. This comment doesn't seem to make much sense to me because you are not ignoring options but collecting options in this else if clause. I'd just remove this comment.

[grimar]

• Addressed review comments.

ELF/Driver.cpp

706–707

Removed. Though it is unobvious I think that "/", "-fresolution=" and "-pass-through=" are options passed
for gold plugin and why should be ignored here.

I wonder if we actually want to error()/warn()/verbose them so that people could adjust their invocations to remove
excessive command line options when using lld instead gold+plugin.

[ruiu]

LGTM

ELF/Driver.cpp

 #include "Symbols.h"
 #include "SyntheticSections.h"
 #include "Target.h"
 #include "Writer.h"
 #include "lld/Common/Args.h"
 #include "lld/Common/Driver.h"
 #include "lld/Common/ErrorHandler.h"
 #include "lld/Common/Memory.h"
+#include "lld/Common/TargetOptionsCommandFlags.h"
 #include "lld/Common/Threads.h"
 #include "lld/Common/Version.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Compression.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/TarWriter.h"
void LinkerDriver::addLibrary(StringRef Name) {
   else
     error("unable to find library -l" + Name);
 }
 
 // This function is called on startup. We need this for LTO since
 // LTO calls LLVM functions to compile bitcode files to native code.
 // Technically this can be delayed until we read bitcode files, but
 // we don't bother to do lazily because the initialization is fast.
-static void initLLVM(opt::InputArgList &Args) {
+static void initLLVM() {
   InitializeAllTargets();
   InitializeAllTargetMCs();
   InitializeAllAsmPrinters();
   InitializeAllAsmParsers();
-
-  // Parse and evaluate -mllvm options.
-  std::vector<const char *> V;
-  V.push_back("lld (LLVM option parsing)");
-  for (auto *Arg : Args.filtered(OPT_mllvm))
-    V.push_back(Arg->getValue());
-  cl::ParseCommandLineOptions(V.size(), V.data());
 }
 
 // Some command line options or some combinations of them are not allowed.
 // This function checks for such errors.
 static void checkOptions(opt::InputArgList &Args) {
   // The MIPS ABI as of 2016 does not support the GNU-style symbol lookup
   // table which is a relatively new feature.
   if (Config->EMachine == EM_MIPS && Config->GnuHash)
if (ErrOrWriter) {
       make<std::unique_ptr<TarWriter>>(std::move(*ErrOrWriter));
     } else {
       error(Twine("--reproduce: failed to open ") + Path + ": " +
             toString(ErrOrWriter.takeError()));
     }
   }
 
   readConfigs(Args);
-  initLLVM(Args);
+  initLLVM();
   createFiles(Args);
   inferMachineType();
   setConfigs();
   checkOptions(Args);
   if (errorCount())
     return;
 
   switch (Config->EKind) {
static int parseInt(StringRef S, opt::Arg *Arg) {
   int V = 0;
   if (!to_integer(S, V, 10))
     error(Arg->getSpelling() + "=" + Arg->getValue() +
           ": number expected, but got '" + S + "'");
   return V;
 }
 
 // Initializes Config members by the command line options.
 void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->AllowMultipleDefinition =
       Args.hasArg(OPT_allow_multiple_definition) || hasZOption(Args, "muldefs");
   Config->AuxiliaryList = args::getStrings(Args, OPT_auxiliary);
   Config->Bsymbolic = Args.hasArg(OPT_Bsymbolic);
   Config->BsymbolicFunctions = Args.hasArg(OPT_Bsymbolic_functions);
   Config->CheckSections =
       Args.hasFlag(OPT_check_sections, OPT_no_check_sections, true);
   Config->Chroot = Args.getLastArgValue(OPT_chroot);
void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->ZRelro = !hasZOption(Args, "norelro");
   Config->ZRetpolineplt = hasZOption(Args, "retpolineplt");
   Config->ZRodynamic = hasZOption(Args, "rodynamic");
   Config->ZStackSize = args::getZOptionValue(Args, OPT_z, "stack-size", 0);
   Config->ZText = !hasZOption(Args, "notext");
   Config->ZWxneeded = hasZOption(Args, "wxneeded");
 
   // Parse LTO plugin-related options for compatibility with gold.
+  std::vector<const char *> LTOOptions({Config->Argv[0].data()});
   for (auto *Arg : Args.filtered(OPT_plugin_opt)) {
     StringRef S = Arg->getValue();
     if (S == "disable-verify")
       Config->DisableVerify = true;
     else if (S == "save-temps")
       Config->SaveTemps = true;
     else if (S.startswith("O"))
       Config->LTOO = parseInt(S.substr(1), Arg);
     else if (S.startswith("lto-partitions="))
       Config->LTOPartitions = parseInt(S.substr(15), Arg);
     else if (S.startswith("jobs="))
       Config->ThinLTOJobs = parseInt(S.substr(5), Arg);
     else if (!S.startswith("/") && !S.startswith("-fresolution=") &&
-             !S.startswith("-pass-through=") && !S.startswith("mcpu=") &&
-             !S.startswith("thinlto") && S != "-function-sections" &&
-             S != "-data-sections")
-      error(Arg->getSpelling() + ": unknown option: " + S);
+             !S.startswith("-pass-through="))
+      LTOOptions.push_back(S.data());
   }
+  // Parse and evaluate -mllvm options.
+  for (auto *Arg : Args.filtered(OPT_mllvm))
+    LTOOptions.push_back(Arg->getValue());
+  cl::ParseCommandLineOptions(LTOOptions.size(), LTOOptions.data());
 
   if (Config->LTOO > 3)
     error("invalid optimization level for LTO: " + Twine(Config->LTOO));
   if (Config->LTOPartitions == 0)
     error("--lto-partitions: number of threads must be > 0");
   if (Config->ThinLTOJobs == 0)
     error("--thinlto-jobs: number of threads must be > 0");
 

test/ELF/lto-plugin-ignore.s

 # REQUIRES: x86
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
 # RUN: ld.lld %t -plugin-opt=/foo/bar -plugin-opt=-fresolution=zed \
 # RUN:   -plugin-opt=-pass-through=-lgcc -plugin-opt=-function-sections \
 # RUN:   -plugin-opt=-data-sections -o /dev/null
 
-# RUN: not ld.lld %t -plugin-opt=-data-sectionssss \
-# RUN:   -plugin-opt=-function-sectionsss 2>&1 | FileCheck %s
-# CHECK: unknown option: -data-sectionsss
-# CHECK: unknown option: -function-sectionsss
+# RUN: not ld.lld %t -plugin-opt=-data-sectionxxx \
+# RUN:   -plugin-opt=-function-sectionxxx 2>&1 | FileCheck %s
+# CHECK: Unknown command line argument '-data-sectionxxx'
+# CHECK: Unknown command line argument '-function-sectionxxx'