[ELF] Add support for -no-gc-sections flag

This flag is supported by both BFD ld and gold and is occasionally
used to negate the effect of -gc-sections flag.

Differential Revision: https://reviews.llvm.org/D24270

llvm-svn: 280729

diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 40607e3..45c6b1b 100644 (file)
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -400,7 +400,7 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->EnableNewDtags = !Args.hasArg(OPT_disable_new_dtags);
   Config->ExportDynamic = Args.hasArg(OPT_export_dynamic);
   Config->FatalWarnings = Args.hasArg(OPT_fatal_warnings);
-  Config->GcSections = Args.hasArg(OPT_gc_sections);
+  Config->GcSections = getArg(Args, OPT_gc_sections, OPT_no_gc_sections, false);
   Config->ICF = Args.hasArg(OPT_icf);
   Config->NoGnuUnique = Args.hasArg(OPT_no_gnu_unique);
   Config->NoUndefinedVersion = Args.hasArg(OPT_no_undefined_version);

diff --git a/lld/ELF/Options.td b/lld/ELF/Options.td
index d37a41a..d8ef1b3 100644 (file)
--- a/lld/ELF/Options.td
+++ b/lld/ELF/Options.td
@@ -106,6 +106,9 @@ def no_as_needed: F<"no-as-needed">,
 def no_demangle: F<"no-demangle">,
   HelpText<"Do not demangle symbol names">;
 
+def no_gc_sections: F<"no-gc-sections">,
+  HelpText<"Disable garbage collection of unused sections">;
+
 def no_gnu_unique: F<"no-gnu-unique">,
   HelpText<"Disable STB_GNU_UNIQUE symbol binding">;