[LLD] Add -z nodlopen option

[kettenis]

Summary

Add -z nodlopen option. This option sets the DF_1_NOOPEN flag, indicating that the generated DSO should not be dlopen'ed.

This option is used by one of the OpenBSD regression tests to check if the flag is respected by our dynamic linker.

[davide]

LGTM

[ruiu]

LGTM

[brad]

Please commit.

[davide]

I'll run this through the testsuite and commit on your behalf soon.

[davide]

r298567.

ELF/Config.h

struct Configuration {
   bool Trace;
   bool Verbose;
   bool WarnCommon;
   bool WarnMissingEntry;
   bool ZCombreloc;
   bool ZExecstack;
   bool ZNocopyreloc;
   bool ZNodelete;
+  bool ZNodlopen;
   bool ZNow;
   bool ZOrigin;
   bool ZRelro;
   bool ZText;
   bool ExitEarly;
   bool ZWxneeded;
   DiscardPolicy Discard;
   SortSectionPolicy SortSection;

ELF/Driver.cpp

void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->Undefined = getArgs(Args, OPT_undefined);
   Config->UnresolvedSymbols = getUnresolvedSymbolPolicy(Args);
   Config->Verbose = Args.hasArg(OPT_verbose);
   Config->WarnCommon = Args.hasArg(OPT_warn_common);
   Config->ZCombreloc = !hasZOption(Args, "nocombreloc");
   Config->ZExecstack = hasZOption(Args, "execstack");
   Config->ZNocopyreloc = hasZOption(Args, "nocopyreloc");
   Config->ZNodelete = hasZOption(Args, "nodelete");
+  Config->ZNodlopen = hasZOption(Args, "nodlopen");
   Config->ZNow = hasZOption(Args, "now");
   Config->ZOrigin = hasZOption(Args, "origin");
   Config->ZRelro = !hasZOption(Args, "norelro");
   Config->ZStackSize = getZOptionValue(Args, "stack-size", 0);
   Config->ZText = !hasZOption(Args, "notext");
   Config->ZWxneeded = hasZOption(Args, "wxneeded");
 
   if (Config->LTOO > 3)

ELF/SyntheticSections.cpp

template <class ELFT> void DynamicSection<ELFT>::addEntries() {
 
   // Set DT_FLAGS and DT_FLAGS_1.
   uint32_t DtFlags = 0;
   uint32_t DtFlags1 = 0;
   if (Config->Bsymbolic)
     DtFlags |= DF_SYMBOLIC;
   if (Config->ZNodelete)
     DtFlags1 |= DF_1_NODELETE;
+  if (Config->ZNodlopen)
+    DtFlags1 |= DF_1_NOOPEN;
   if (Config->ZNow) {
     DtFlags |= DF_BIND_NOW;
     DtFlags1 |= DF_1_NOW;
   }
   if (Config->ZOrigin) {
     DtFlags |= DF_ORIGIN;
     DtFlags1 |= DF_1_ORIGIN;
   }

test/ELF/dt_flags.s

 # REQUIRES: x86
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
 # RUN: ld.lld -shared %t -o %t.so
-# RUN: ld.lld -z now -z nodelete -z origin -Bsymbolic %t %t.so -o %t1
+# RUN: ld.lld -z now -z nodelete -z nodlopen -z origin -Bsymbolic %t %t.so -o %t1
 # RUN: ld.lld %t %t.so -o %t2
 # RUN: llvm-readobj -dynamic-table %t1 | FileCheck -check-prefix=FLAGS %s
 # RUN: llvm-readobj -dynamic-table %t2 | FileCheck %s
 
 # FLAGS: DynamicSection [
 # FLAGS:   0x000000000000001E FLAGS ORIGIN SYMBOLIC BIND_NOW
-# FLAGS:   0x000000006FFFFFFB FLAGS_1 NOW NODELETE ORIGIN
+# FLAGS:   0x000000006FFFFFFB FLAGS_1 NOW NODELETE NOOPEN ORIGIN
 # FLAGS: ]
 
 # CHECK: DynamicSection [
 # CHECK-NOT:   0x000000000000001E FLAGS ORIGIN SYMBOLIC BIND_NOW
-# CHECK-NOT:   0x000000006FFFFFFB FLAGS_1 NOW NODELETE ORIGIN
+# CHECK-NOT:   0x000000006FFFFFFB FLAGS_1 NOW NODELETE NOOPEN ORIGIN
 # CHECK: ]
 
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