Index: lld/trunk/ELF/Driver.cpp
===================================================================
--- lld/trunk/ELF/Driver.cpp
+++ lld/trunk/ELF/Driver.cpp
@@ -1613,11 +1613,8 @@
 
   // We do not want to emit debug sections if --strip-all
   // or -strip-debug are given.
-  if (Config->Strip != StripPolicy::None) {
-    llvm::erase_if(InputSections, [](InputSectionBase *S) {
-      return S->Name.startswith(".debug") || S->Name.startswith(".zdebug");
-    });
-  }
+  if (Config->Strip != StripPolicy::None)
+    llvm::erase_if(InputSections, [](InputSectionBase *S) { return S->Debug; });
 
   // The Target instance handles target-specific stuff, such as applying
   // relocations or writing a PLT section. It also contains target-dependent
Index: lld/trunk/ELF/InputFiles.h
===================================================================
--- lld/trunk/ELF/InputFiles.h
+++ lld/trunk/ELF/InputFiles.h
@@ -234,6 +234,10 @@
   // but had one or more functions with the no_split_stack attribute.
   bool SomeNoSplitStack = false;
 
+  // True if the file has any live Regular or Merge sections that aren't
+  // the LDSA section.
+  bool HasLiveCodeOrData = false;
+
   // Pointer to this input file's .llvm_addrsig section, if it has one.
   const Elf_Shdr *AddrsigSec = nullptr;
 
Index: lld/trunk/ELF/InputSection.h
===================================================================
--- lld/trunk/ELF/InputSection.h
+++ lld/trunk/ELF/InputSection.h
@@ -51,7 +51,7 @@
 
   unsigned SectionKind : 3;
 
-  // The next three bit fields are only used by InputSectionBase, but we
+  // The next four bit fields are only used by InputSectionBase, but we
   // put them here so the struct packs better.
 
   // The garbage collector sets sections' Live bits.
@@ -73,6 +73,9 @@
 
   unsigned Bss : 1;
 
+  // True if this is a debuginfo section.
+  unsigned Debug : 1;
+
   // Set for sections that should not be folded by ICF.
   unsigned KeepUnique : 1;
 
@@ -100,8 +103,9 @@
               uint64_t Entsize, uint64_t Alignment, uint32_t Type,
               uint32_t Info, uint32_t Link)
       : Name(Name), Repl(this), SectionKind(SectionKind), Live(false),
-        Assigned(false), Bss(false), KeepUnique(false), Alignment(Alignment),
-        Flags(Flags), Entsize(Entsize), Type(Type), Link(Link), Info(Info) {}
+        Assigned(false), Bss(false), Debug(false), KeepUnique(false),
+        Alignment(Alignment), Flags(Flags), Entsize(Entsize), Type(Type),
+        Link(Link), Info(Info) {}
 };
 
 // This corresponds to a section of an input file.
Index: lld/trunk/ELF/InputSection.cpp
===================================================================
--- lld/trunk/ELF/InputSection.cpp
+++ lld/trunk/ELF/InputSection.cpp
@@ -71,6 +71,7 @@
 
   NumRelocations = 0;
   AreRelocsRela = false;
+  Debug = Name.startswith(".debug") || Name.startswith(".zdebug");
 
   // The ELF spec states that a value of 0 means the section has
   // no alignment constraits.
Index: lld/trunk/ELF/MarkLive.cpp
===================================================================
--- lld/trunk/ELF/MarkLive.cpp
+++ lld/trunk/ELF/MarkLive.cpp
@@ -47,7 +47,7 @@
   void run();
 
 private:
-  void enqueue(InputSectionBase *Sec, uint64_t Offset);
+  void enqueue(InputSectionBase *Sec, uint64_t Offset, bool IsLSDA);
   void markSymbol(Symbol *Sym);
 
   template <class RelTy>
@@ -97,7 +97,7 @@
       Offset += getAddend<ELFT>(Sec, Rel);
 
     if (!IsLSDA || !(RelSec->Flags & SHF_EXECINSTR))
-      enqueue(RelSec, Offset);
+      enqueue(RelSec, Offset, IsLSDA);
     return;
   }
 
@@ -106,7 +106,7 @@
       SS->getFile().IsNeeded = true;
 
   for (InputSectionBase *Sec : CNamedSections.lookup(Sym.getName()))
-    enqueue(Sec, 0);
+    enqueue(Sec, 0, IsLSDA);
 }
 
 // The .eh_frame section is an unfortunate special case.
@@ -169,7 +169,8 @@
 }
 
 template <class ELFT>
-void MarkLive<ELFT>::enqueue(InputSectionBase *Sec, uint64_t Offset) {
+void MarkLive<ELFT>::enqueue(InputSectionBase *Sec, uint64_t Offset,
+                             bool IsLSDA) {
   // Skip over discarded sections. This in theory shouldn't happen, because
   // the ELF spec doesn't allow a relocation to point to a deduplicated
   // COMDAT section directly. Unfortunately this happens in practice (e.g.
@@ -183,19 +184,26 @@
   if (auto *MS = dyn_cast<MergeInputSection>(Sec))
     MS->getSectionPiece(Offset)->Live = true;
 
+  InputSection *S = dyn_cast<InputSection>(Sec);
+  // LSDA does not count as "live code or data" in the object file.
+  // The section may already have been marked live for LSDA in which
+  // case we still need to mark the file.
+  if (S && !IsLSDA && Sec->File)
+    Sec->getFile<ELFT>()->HasLiveCodeOrData = true;
+
   if (Sec->Live)
     return;
-  Sec->Live = true;
 
+  Sec->Live = true;
   // Add input section to the queue.
-  if (InputSection *S = dyn_cast<InputSection>(Sec))
+  if (S)
     Queue.push_back(S);
 }
 
 template <class ELFT> void MarkLive<ELFT>::markSymbol(Symbol *Sym) {
   if (auto *D = dyn_cast_or_null<Defined>(Sym))
     if (auto *IS = dyn_cast_or_null<InputSectionBase>(D->Section))
-      enqueue(IS, D->Value);
+      enqueue(IS, D->Value, false);
 }
 
 // This is the main function of the garbage collector.
@@ -239,7 +247,7 @@
       continue;
 
     if (isReserved(Sec) || Script->shouldKeep(Sec)) {
-      enqueue(Sec, 0);
+      enqueue(Sec, 0, false);
     } else if (isValidCIdentifier(Sec->Name)) {
       CNamedSections[Saver.save("__start_" + Sec->Name)].push_back(Sec);
       CNamedSections[Saver.save("__stop_" + Sec->Name)].push_back(Sec);
@@ -259,7 +267,7 @@
     }
 
     for (InputSectionBase *IS : Sec.DependentSections)
-      enqueue(IS, 0);
+      enqueue(IS, 0, false);
   }
 }
 
@@ -285,7 +293,7 @@
   // The -gc-sections option works only for SHF_ALLOC sections
   // (sections that are memory-mapped at runtime). So we can
   // unconditionally make non-SHF_ALLOC sections alive except
-  // SHF_LINK_ORDER and SHT_REL/SHT_RELA sections.
+  // SHF_LINK_ORDER and SHT_REL/SHT_RELA sections and .debug sections.
   //
   // Usually, SHF_ALLOC sections are not removed even if they are
   // unreachable through relocations because reachability is not
@@ -306,13 +314,19 @@
     bool IsLinkOrder = (Sec->Flags & SHF_LINK_ORDER);
     bool IsRel = (Sec->Type == SHT_REL || Sec->Type == SHT_RELA);
 
-    if (!IsAlloc && !IsLinkOrder && !IsRel)
+    if (!IsAlloc && !IsLinkOrder && !IsRel && !Sec->Debug)
       Sec->Live = true;
   }
 
   // Follow the graph to mark all live sections.
   MarkLive<ELFT>().run();
 
+  // Mark debug sections as live in any object file that has a live
+  // Regular or Merge section.
+  for (InputSectionBase *Sec : InputSections)
+    if (Sec->Debug && Sec->getFile<ELFT>()->HasLiveCodeOrData)
+      Sec->Live = true;
+
   // Report garbage-collected sections.
   if (Config->PrintGcSections)
     for (InputSectionBase *Sec : InputSections)
Index: lld/trunk/test/ELF/linkerscript/comdat-gc.s
===================================================================
--- lld/trunk/test/ELF/linkerscript/comdat-gc.s
+++ lld/trunk/test/ELF/linkerscript/comdat-gc.s
@@ -8,6 +8,9 @@
 
 # GC1:     Name: .debug_line
 
+# Add .ctors section so all debuginfo isn't GCed
+.section  .ctors,"ax",@progbits
+
 .file 1 "test/ELF/linkerscript/comdat_gc.s"
 .section  .text._Z3fooIiEvv,"axG",@progbits,_Z3fooIiEvv,comdat
 .loc 1 14
Index: lld/trunk/test/ELF/linkerscript/debuginfo-gc.s
===================================================================
--- lld/trunk/test/ELF/linkerscript/debuginfo-gc.s
+++ lld/trunk/test/ELF/linkerscript/debuginfo-gc.s
@@ -0,0 +1,14 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/comdat-gc.s -o %t1
+# RUN: echo "SECTIONS { .text : { *(.text*) } }" > %t.script
+# RUN: ld.lld --gc-sections --script %t.script %t %t1 -o %t2
+# RUN: llvm-readobj -sections -symbols %t2 | FileCheck %s
+
+# CHECK-NOT: Name: .debug_line
+
+.file 1 "test/ELF/linkerscript/comdat_gc.s"
+.section  .text._Z3fooIiEvv,"axG",@progbits,_Z3fooIiEvv,comdat
+.loc 1 14
+  ret