ELF: Add --no-gnu-unique option.

When the option is specified, then all STB_GNU_UNIQUE symbols are
converted to STB_GLOBAL symbols.

llvm-svn: 265717

5 files changed, 30 insertions, 10 deletions

diff --git a/lld/ELF/Config.h b/lld/ELF/Config.h
index ea94f88f2ba..8c48996aaa6 100644
--- a/lld/ELF/Config.h
+++ b/lld/ELF/Config.h
@@ -67,6 +67,7 @@ struct Configuration {
   bool GnuHash = false;
   bool ICF;
   bool Mips64EL = false;
+  bool NoGnuUnique;
   bool NoUndefined;
   bool NoinhibitExec;
   bool Pic;
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index ab3335bb900..72e4bae505d 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -282,6 +282,7 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->ExportDynamic = Args.hasArg(OPT_export_dynamic);
   Config->GcSections = Args.hasArg(OPT_gc_sections);
   Config->ICF = Args.hasArg(OPT_icf);
+  Config->NoGnuUnique = Args.hasArg(OPT_no_gnu_unique);
   Config->NoUndefined = Args.hasArg(OPT_no_undefined);
   Config->NoinhibitExec = Args.hasArg(OPT_noinhibit_exec);
   Config->Pie = Args.hasArg(OPT_pie);
diff --git a/lld/ELF/Options.td b/lld/ELF/Options.td
index 8b72fcacf68..b1881f21fab 100644
--- a/lld/ELF/Options.td
+++ b/lld/ELF/Options.td
@@ -91,6 +91,9 @@ def no_as_needed : Flag<["--"], "no-as-needed">;
 def no_demangle: Flag<["--"], "no-demangle">,
   HelpText<"Do not demangle symbol names">;
 
+def no_gnu_unique : Flag<["--"], "no-gnu-unique">,
+  HelpText<"Disable STB_GNU_UNIQUE symbol binding">;
+
 def no_whole_archive : Flag<["--", "-"], "no-whole-archive">,
   HelpText<"Restores the default behavior of loading archive members">;
 
diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index f79a1d3a923..9d00caf41e7 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -1515,6 +1515,8 @@ uint8_t SymbolTableSection<ELFT>::getSymbolBinding(SymbolBody *Body) {
   uint8_t Visibility = Body->getVisibility();
   if (Visibility != STV_DEFAULT && Visibility != STV_PROTECTED)
     return STB_LOCAL;
+  if (Config->NoGnuUnique && Body->Binding == STB_GNU_UNIQUE)
+    return STB_GLOBAL;
   return Body->Binding;
 }
 
diff --git a/lld/test/ELF/gnu-unique.s b/lld/test/ELF/gnu-unique.s
index f7206cf8c97..afc0da27063 100644
--- a/lld/test/ELF/gnu-unique.s
+++ b/lld/test/ELF/gnu-unique.s
@@ -1,7 +1,11 @@
+// REQUIRES: x86
 // RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t
+//
 // RUN: ld.lld %t -shared -o %tout.so
-// RUN: llvm-readobj -dyn-symbols %tout.so | FileCheck %s
-// REQUIRES: x86
+// RUN: llvm-readobj -dyn-symbols %tout.so | FileCheck -check-prefix=GNU %s
+//
+// RUN: ld.lld %t -shared -o %tout.so --no-gnu-unique
+// RUN: llvm-readobj -dyn-symbols %tout.so | FileCheck -check-prefix=NO %s
 
 // Check that STB_GNU_UNIQUE is treated as a global and ends up in the dynamic
 // symbol table as STB_GNU_UNIQUE.
@@ -14,11 +18,20 @@ _start:
 .type symb, @gnu_unique_object
 symb:
 
-# CHECK:        Name: symb@
-# CHECK-NEXT:   Value:
-# CHECK-NEXT:   Size: 0
-# CHECK-NEXT:   Binding: Unique
-# CHECK-NEXT:   Type: Object
-# CHECK-NEXT:   Other: 0
-# CHECK-NEXT:   Section: .data
-# CHECK-NEXT: }
+# GNU:        Name: symb@
+# GNU-NEXT:   Value:
+# GNU-NEXT:   Size: 0
+# GNU-NEXT:   Binding: Unique
+# GNU-NEXT:   Type: Object
+# GNU-NEXT:   Other: 0
+# GNU-NEXT:   Section: .data
+# GNU-NEXT: }
+
+# NO:        Name: symb@
+# NO-NEXT:   Value:
+# NO-NEXT:   Size: 0
+# NO-NEXT:   Binding: Global
+# NO-NEXT:   Type: Object
+# NO-NEXT:   Other: 0
+# NO-NEXT:   Section: .data
+# NO-NEXT: }