[lld] r296097 - [ELF] - Implemented --no-dynamic-linker option

[George Rimar via llvm-commits]

Author: grimar
Date: Fri Feb 24 02:26:18 2017
New Revision: 296097

URL: http://llvm.org/viewvc/llvm-project?rev=296097&view=rev
Log:
[ELF] - Implemented --no-dynamic-linker option

Feature is used for producing static-linked PIE executables
(https://gcc.gnu.org/ml/gcc/2015-06/msg00008.html)
And was implemented in GNU ld https://gcc.gnu.org/ml/gcc/2015-08/msg00099.html

I also found it in linux kernel build system,
though I think that x86/x64 bootloader does not really rely on it.
Seems it used for PPC though.

Differential revision: https://reviews.llvm.org/D30258

Added:
    lld/trunk/test/ELF/no-dynamic-linker.s
Modified:
    lld/trunk/ELF/Driver.cpp
    lld/trunk/ELF/Options.td

Modified: lld/trunk/ELF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.cpp?rev=296097&r1=296096&r2=296097&view=diff
==============================================================================
--- lld/trunk/ELF/Driver.cpp (original)
+++ lld/trunk/ELF/Driver.cpp Fri Feb 24 02:26:18 2017
@@ -434,6 +434,13 @@ static DiscardPolicy getDiscardOption(op
   return DiscardPolicy::None;
 }
 
+static StringRef getDynamicLinkerOption(opt::InputArgList &Args) {
+  auto *Arg = Args.getLastArg(OPT_dynamic_linker, OPT_no_dynamic_linker);
+  if (!Arg || Arg->getOption().getID() == OPT_no_dynamic_linker)
+    return "";
+  return Arg->getValue();
+}
+
 static StripPolicy getStripOption(opt::InputArgList &Args) {
   if (auto *Arg = Args.getLastArg(OPT_strip_all, OPT_strip_debug)) {
     if (Arg->getOption().getID() == OPT_strip_all)
@@ -548,8 +555,6 @@ void LinkerDriver::readConfigs(opt::Inpu
   Config->Trace = Args.hasArg(OPT_trace);
   Config->Verbose = Args.hasArg(OPT_verbose);
   Config->WarnCommon = Args.hasArg(OPT_warn_common);
-
-  Config->DynamicLinker = getString(Args, OPT_dynamic_linker);
   Config->Entry = getString(Args, OPT_entry);
   Config->Fini = getString(Args, OPT_fini, "_fini");
   Config->Init = getString(Args, OPT_init, "_init");
@@ -582,6 +587,7 @@ void LinkerDriver::readConfigs(opt::Inpu
   Config->ZStackSize = getZOptionValue(Args, "stack-size", 0);
   Config->ZWxneeded = hasZOption(Args, "wxneeded");
 
+  Config->DynamicLinker = getDynamicLinkerOption(Args);
   Config->OFormatBinary = isOutputFormatBinary(Args);
   Config->SectionStartMap = getSectionStartMap(Args);
   Config->SortSection = getSortKind(Args);

Modified: lld/trunk/ELF/Options.td
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Options.td?rev=296097&r1=296096&r2=296097&view=diff
==============================================================================
--- lld/trunk/ELF/Options.td (original)
+++ lld/trunk/ELF/Options.td Fri Feb 24 02:26:18 2017
@@ -148,6 +148,9 @@ def no_define_common: F<"no-define-commo
 def no_demangle: F<"no-demangle">,
   HelpText<"Do not demangle symbol names">;
 
+def no_dynamic_linker: F<"no-dynamic-linker">,
+  HelpText<"Inhibit output of .interp section">;
+
 def no_export_dynamic: F<"no-export-dynamic">;
 def no_fatal_warnings: F<"no-fatal-warnings">;
 
@@ -357,7 +360,6 @@ def no_add_needed: F<"no-add-needed">;
 def no_allow_shlib_undefined: F<"no-allow-shlib-undefined">;
 def no_copy_dt_needed_entries: F<"no-copy-dt-needed-entries">,
   Alias<no_add_needed>;
-def no_dynamic_linker: F<"no-dynamic-linker">;
 def no_mmap_output_file: F<"no-mmap-output-file">;
 def no_warn_common: F<"no-warn-common">;
 def no_warn_mismatch: F<"no-warn-mismatch">;

Added: lld/trunk/test/ELF/no-dynamic-linker.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/no-dynamic-linker.s?rev=296097&view=auto
==============================================================================
--- lld/trunk/test/ELF/no-dynamic-linker.s (added)
+++ lld/trunk/test/ELF/no-dynamic-linker.s Fri Feb 24 02:26:18 2017
@@ -0,0 +1,12 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/shared.s -o %tso.o
+# RUN: ld.lld -shared %tso.o -o %t.so
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+
+# RUN: ld.lld -dynamic-linker foo --no-dynamic-linker %t.o %t.so -o %t
+# RUN: llvm-readobj --program-headers %t | FileCheck %s --check-prefix=NODL
+# NODL-NOT: PT_INTERP
+
+# RUN: ld.lld --no-dynamic-linker -dynamic-linker foo %t.o %t.so -o %t
+# RUN: llvm-readobj --program-headers %t | FileCheck %s --check-prefix=WITHDL
+# WITHDL: PT_INTERP