Add "-z lazy" and "-z relro".

[ruiu]

Summary

Add "-z lazy" and "-z relro".

[tmsriram]

lld/ELF/Driver.cpp

762 ↗

(On Diff #143382)

From man ld , Same here, "combreloc"

765 ↗

(On Diff #143382)

This is probably ok or maybe needs "copyreloc". In general, should every option here be negatable?

[ruiu]

lld/ELF/Driver.cpp

765 ↗

(On Diff #143382)

I'll add all gold's negative options. I'll upload a new patch.

[ruiu]

• add more flags
• add tests

[• espindola]

LGTM

ELF/Config.h

struct Configuration {
   bool Trace;
   bool UndefinedVersion;
   bool WarnBackrefs;
   bool WarnCommon;
   bool WarnMissingEntry;
   bool WarnSymbolOrdering;
   bool WriteAddends;
   bool ZCombreloc;
+  bool ZCopyreloc;
   bool ZExecstack;
   bool ZHazardplt;
-  bool ZNocopyreloc;
   bool ZNodelete;
   bool ZNodlopen;
   bool ZNow;
   bool ZOrigin;
   bool ZRelro;
   bool ZRodynamic;
   bool ZText;
   bool ZRetpolineplt;

ELF/Driver.cpp

 
 static bool hasZOption(opt::InputArgList &Args, StringRef Key) {
   for (auto *Arg : Args.filtered(OPT_z))
     if (Key == Arg->getValue())
       return true;
   return false;
 }
 
+static bool getZFlag(opt::InputArgList &Args, StringRef K1, StringRef K2,
+                     bool Default) {
+  for (auto *Arg : Args.filtered_reverse(OPT_z)) {
+    if (K1 == Arg->getValue())
+      return true;
+    if (K2 == Arg->getValue())
+      return false;
+  }
+  return Default;
+}
+
 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
void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->UndefinedVersion =
       Args.hasFlag(OPT_undefined_version, OPT_no_undefined_version, true);
   Config->UnresolvedSymbols = getUnresolvedSymbolPolicy(Args);
   Config->WarnBackrefs =
       Args.hasFlag(OPT_warn_backrefs, OPT_no_warn_backrefs, false);
   Config->WarnCommon = Args.hasFlag(OPT_warn_common, OPT_no_warn_common, false);
   Config->WarnSymbolOrdering =
       Args.hasFlag(OPT_warn_symbol_ordering, OPT_no_warn_symbol_ordering, true);
-  Config->ZCombreloc = !hasZOption(Args, "nocombreloc");
-  Config->ZExecstack = hasZOption(Args, "execstack");
+  Config->ZCombreloc = getZFlag(Args, "combreloc", "nocombreloc", true);
+  Config->ZCopyreloc = getZFlag(Args, "copyreloc", "nocopyreloc", true);
+  Config->ZExecstack = getZFlag(Args, "execstack", "noexecstack", false);
   Config->ZHazardplt = hasZOption(Args, "hazardplt");
-  Config->ZNocopyreloc = hasZOption(Args, "nocopyreloc");
   Config->ZNodelete = hasZOption(Args, "nodelete");
   Config->ZNodlopen = hasZOption(Args, "nodlopen");
-  Config->ZNow = hasZOption(Args, "now");
+  Config->ZNow = getZFlag(Args, "now", "lazy", false);
   Config->ZOrigin = hasZOption(Args, "origin");
-  Config->ZRelro = !hasZOption(Args, "norelro");
+  Config->ZRelro = getZFlag(Args, "relro", "norelro", true);
   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->ZText = getZFlag(Args, "text", "notext", true);
   Config->ZWxneeded = hasZOption(Args, "wxneeded");
 
   // Parse LTO plugin-related options for compatibility with gold.
   for (auto *Arg : Args.filtered(OPT_plugin_opt)) {
     StringRef S = Arg->getValue();
     if (S == "disable-verify")
       Config->DisableVerify = true;
     else if (S == "save-temps")

ELF/Relocations.cpp

error("cannot preempt symbol: " + toString(Sym) +
           getLocation(Sec, Sym, Offset));
     return Expr;
   }
 
   if (Sym.isObject()) {
     // Produce a copy relocation.
     auto &SS = cast<SharedSymbol>(Sym);
     if (!SS.CopyRelSec) {
-      if (Config->ZNocopyreloc)
+      if (!Config->ZCopyreloc)
         error("unresolvable relocation " + toString(Type) +
               " against symbol '" + toString(SS) +
               "'; recompile with -fPIC or remove '-z nocopyreloc'" +
               getLocation(Sec, Sym, Offset));
       addCopyRelSymbol<ELFT>(SS);
     }
     Sec.Relocations.push_back({Expr, Type, Offset, Addend, &Sym});
     return Expr;

test/ELF/combrelocs.s

 # REQUIRES: x86
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
 # RUN: ld.lld -shared %t.o -o %t.out
 # RUN: llvm-readobj -r --expand-relocs --dynamic-table %t.out | FileCheck %s
 
+# RUN: ld.lld -shared %t.o -o %t.out -z combreloc
+# RUN: llvm-readobj -r --expand-relocs --dynamic-table %t.out | FileCheck %s
+
 # CHECK:      Relocations [
 # CHECK-NEXT:   Section ({{.*}}) .rela.dyn {
 # CHECK-NEXT:     Relocation {
 # CHECK-NEXT:       Offset: 0x1000
 # CHECK-NEXT:       Type: R_X86_64_64
 # CHECK-NEXT:       Symbol: aaa (1)
 # CHECK-NEXT:       Addend: 0x0
 # CHECK-NEXT:     }

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 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: ld.lld %t %t.so -o %t2
+# RUN: llvm-readobj -dynamic-table %t2 | FileCheck %s
+
+# RUN: ld.lld -z lazy %t %t.so -o %t2
 # RUN: llvm-readobj -dynamic-table %t2 | FileCheck %s
 
 # FLAGS: DynamicSection [
 # FLAGS:   0x000000000000001E FLAGS ORIGIN SYMBOLIC BIND_NOW
 # 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 NOOPEN ORIGIN
 # CHECK: ]
 
 .globl _start
 _start:

test/ELF/gnustack.s

 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t1
+
 # RUN: ld.lld %t1 -z execstack -o %t
 # RUN: llvm-readobj --program-headers -s %t | FileCheck --check-prefix=RWX %s
+
 # RUN: ld.lld %t1 -o %t
 # RUN: llvm-readobj --program-headers -s %t | FileCheck --check-prefix=RW %s
 
+# RUN: ld.lld %t1 -o %t -z noexecstack
+# RUN: llvm-readobj --program-headers -s %t | FileCheck --check-prefix=RW %s
+
 # RW:      Type: PT_GNU_STACK
 # RW-NEXT: Offset: 0x0
 # RW-NEXT: VirtualAddress: 0x0
 # RW-NEXT: PhysicalAddress: 0x0
 # RW-NEXT: FileSize: 0
 # RW-NEXT: MemSize: 0
 # RW-NEXT: Flags [
 # RW-NEXT:   PF_R

test/ELF/relro.s

+// REQUIRES: x86
+
 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/shared.s -o %t2.o
 // RUN: ld.lld -shared %t2.o -o %t2.so
-// RUN: ld.lld %t.o %t2.so -z now -z relro -o %t
+
+// RUN: ld.lld %t.o %t2.so -z now -z norelro -z relro -o %t
 // RUN: llvm-readobj -l --elf-output-style=GNU %t | FileCheck --check-prefix=CHECK --check-prefix=FULLRELRO %s
-// RUN: ld.lld %t.o %t2.so -z relro -o %t
+
+// RUN: ld.lld %t.o %t2.so -z norelro -z relro -o %t
 // RUN: llvm-readobj -l --elf-output-style=GNU %t | FileCheck --check-prefix=CHECK --check-prefix=PARTRELRO %s
+
 // RUN: ld.lld %t.o %t2.so -z norelro -o %t
 // RUN: llvm-readobj -l --elf-output-style=GNU %t | FileCheck --check-prefix=NORELRO %s
-// REQUIRES: x86
 
 // CHECK:      Program Headers:
 // CHECK-NEXT: Type
 // CHECK-NEXT: PHDR
 // CHECK-NEXT: LOAD
 // CHECK-NEXT: LOAD
 // CHECK-NEXT: LOAD
 // CHECK-NEXT: DYNAMIC

test/ELF/ztext.s

 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/ztext.s -o %t2.o
 # RUN: ld.lld %t2.o -o %t2.so -shared
+
 # RUN: ld.lld -z notext %t.o %t2.so -o %t -shared
 # RUN: llvm-readobj  -dynamic-table -r %t | FileCheck %s
 # RUN: ld.lld -z notext %t.o %t2.so -o %t2 -pie
 # RUN: llvm-readobj  -dynamic-table -r %t2 | FileCheck %s
 # RUN: ld.lld -z notext %t.o %t2.so -o %t3
 # RUN: llvm-readobj  -dynamic-table -r %t3 | FileCheck --check-prefix=STATIC %s
 
+# RUN: not ld.lld %t.o %t2.so -o %t -shared 2>&1 | FileCheck --check-prefix=ERR %s
+# RUN: not ld.lld -z text %t.o %t2.so -o %t -shared 2>&1 | FileCheck --check-prefix=ERR %s
+# ERR: error: can't create dynamic relocation
+
 # If the preference is to have text relocations, don't create plt of copy relocations.
 
 # CHECK:      Relocations [
 # CHECK-NEXT:   Section {{.*}} .rela.dyn {
 # CHECK-NEXT:     0x1000 R_X86_64_RELATIVE - 0x1000
 # CHECK-NEXT:     0x1008 R_X86_64_64 bar 0x0
 # CHECK-NEXT:     0x1010 R_X86_64_PC64 zed 0x0
 # CHECK-NEXT:   }