[GNU/ELF] Add support for -X/--discard-locals.

There's (almost) never need to keep .L symbols around for production
builds. In fact, the FreeBSD kernel explicitly specify -X beacuse the
size impact (and the subsequent performance impact) might be significant,
because we keep symbols in memory.
I was tempted to make this the default, but I haven't (yet).

PR:		23232
llvm-svn: 235357

1 files changed, 5 insertions, 0 deletions

diff --git a/lld/include/lld/ReaderWriter/ELFLinkingContext.h b/lld/include/lld/ReaderWriter/ELFLinkingContext.h
index 7f1e7307e7a..28c6ce11e01 100644
--- a/lld/include/lld/ReaderWriter/ELFLinkingContext.h
+++ b/lld/include/lld/ReaderWriter/ELFLinkingContext.h
@@ -314,6 +314,10 @@ public:
   bool discardLocals() const { return _discardLocals; }
   void setDiscardLocals(bool d) { _discardLocals = d; }
 
+  /// \brief Discard temprorary local symbols.
+  bool discardTempLocals() const { return _discardTempLocals; }
+  void setDiscardTempLocals(bool d) { _discardTempLocals = d; }
+
   /// \brief Strip symbols.
   bool stripSymbols() const { return _stripSymbols; }
   void setStripSymbols(bool strip) { _stripSymbols = strip; }
@@ -370,6 +374,7 @@ protected:
   bool _noAllowDynamicLibraries = false;
   bool _mergeRODataToTextSegment = true;
   bool _demangle = true;
+  bool _discardTempLocals = false;
   bool _discardLocals = false;
   bool _stripSymbols = false;
   bool _alignSegments = true;