Index: ELF/InputSection.h
===================================================================
--- ELF/InputSection.h
+++ ELF/InputSection.h
@@ -82,6 +82,8 @@
   template <bool isRela>
   void relocate(uint8_t *Buf, uint8_t *BufEnd, RelIteratorRange<isRela> Rels);
 
+  StringRef getOutputSectionName();
+
 private:
   template <bool isRela>
   uint8_t *findMipsPairedReloc(uint8_t *Buf, uint32_t SymIndex, uint32_t Type,
Index: ELF/InputSection.cpp
===================================================================
--- ELF/InputSection.cpp
+++ ELF/InputSection.cpp
@@ -11,6 +11,7 @@
 #include "Config.h"
 #include "Error.h"
 #include "InputFiles.h"
+#include "LinkerScript.h"
 #include "OutputSections.h"
 #include "Target.h"
 
@@ -243,6 +244,20 @@
   }
 }
 
+template <class ELFT> StringRef InputSectionBase<ELFT>::getOutputSectionName() {
+  StringRef Dest = Script->getOutputSection<ELFT>(this);
+  if (!Dest.empty())
+    return Dest;
+
+  StringRef Name = getSectionName();
+  for (StringRef V : {".text.", ".rodata.", ".data.rel.ro.", ".data.", ".bss.",
+                      ".init_array.", ".fini_array.", ".ctors.", ".dtors.",
+                      ".tbss.", ".gcc_except_table.", ".tdata."})
+    if (Name.startswith(V))
+      return V.drop_back();
+  return Name;
+}
+
 template <class ELFT> void InputSection<ELFT>::writeTo(uint8_t *Buf) {
   if (this->Header->sh_type == SHT_NOBITS)
     return;
Index: ELF/MarkLive.cpp
===================================================================
--- ELF/MarkLive.cpp
+++ ELF/MarkLive.cpp
@@ -76,6 +76,20 @@
   }
 }
 
+// Reference to __start or __stop is sufficient to prevent the section from
+// being garbage collected. Function returns if section should be kept.
+template <class ELFT>
+static bool isRetained(SymbolTable<ELFT> *Symtab, InputSectionBase<ELFT> *Sec) {
+  StringRef Name = Sec->getOutputSectionName();
+  if (!isValidCIdentifier(Name))
+    return false;
+  if (SymbolBody *B = Symtab->find(("__start_" + Name).str()))
+    if (B->isUndefined())
+      return true;
+  SymbolBody *B = Symtab->find(("__stop_" + Name).str());
+  return B && B->isUndefined();
+}
+
 // This is the main function of the garbage collector.
 // Starting from GC-root sections, this function visits all reachable
 // sections to set their "Live" bits.
@@ -116,8 +130,9 @@
   // Preserve special sections.
   for (const std::unique_ptr<ObjectFile<ELFT>> &F : Symtab->getObjectFiles())
     for (InputSectionBase<ELFT> *Sec : F->getSections())
-      if (Sec && Sec != &InputSection<ELFT>::Discarded && isReserved(Sec))
-        Enqueue(Sec);
+      if (Sec && Sec != &InputSection<ELFT>::Discarded)
+        if (isReserved(Sec) || isRetained(Symtab, Sec))
+          Enqueue(Sec);
 
   // Mark all reachable sections.
   while (!Q.empty())
Index: ELF/OutputSections.h
===================================================================
--- ELF/OutputSections.h
+++ ELF/OutputSections.h
@@ -55,6 +55,8 @@
 
 bool canBePreempted(const SymbolBody *Body, bool NeedsGot);
 
+bool isValidCIdentifier(StringRef S);
+
 // This represents a section in an output file.
 // Different sub classes represent different types of sections. Some contain
 // input sections, others are created by the linker.
Index: ELF/OutputSections.cpp
===================================================================
--- ELF/OutputSections.cpp
+++ ELF/OutputSections.cpp
@@ -24,6 +24,19 @@
 using namespace lld;
 using namespace lld::elf2;
 
+static bool isAlpha(char C) {
+  return ('a' <= C && C <= 'z') || ('A' <= C && C <= 'Z') || C == '_';
+}
+
+static bool isAlnum(char C) { return isAlpha(C) || ('0' <= C && C <= '9'); }
+
+// Returns true if S is valid as a C language identifier.
+bool elf2::isValidCIdentifier(StringRef S) {
+  if (S.empty() || !isAlpha(S[0]))
+    return false;
+  return std::all_of(S.begin() + 1, S.end(), isAlnum);
+}
+
 template <class ELFT>
 OutputSectionBase<ELFT>::OutputSectionBase(StringRef Name, uint32_t Type,
                                            uintX_t Flags)
Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -74,7 +74,6 @@
   void writeHeader();
   void writeSections();
   bool isDiscarded(InputSectionBase<ELFT> *IS) const;
-  StringRef getOutputSectionName(InputSectionBase<ELFT> *S) const;
   bool needsInterpSection() const {
     return !Symtab.getSharedFiles().empty() && !Config->DynamicLinker.empty();
   }
@@ -726,21 +725,6 @@
 }
 
 template <class ELFT>
-StringRef Writer<ELFT>::getOutputSectionName(InputSectionBase<ELFT> *S) const {
-  StringRef Dest = Script->getOutputSection<ELFT>(S);
-  if (!Dest.empty())
-    return Dest;
-
-  StringRef Name = S->getSectionName();
-  for (StringRef V : {".text.", ".rodata.", ".data.rel.ro.", ".data.", ".bss.",
-                      ".init_array.", ".fini_array.", ".ctors.", ".dtors.",
-                      ".tbss.", ".gcc_except_table.", ".tdata."})
-    if (Name.startswith(V))
-      return V.drop_back();
-  return Name;
-}
-
-template <class ELFT>
 void reportDiscarded(InputSectionBase<ELFT> *IS,
                      const std::unique_ptr<ObjectFile<ELFT>> &File) {
   if (!Config->PrintGcSections || !IS || IS->isLive())
@@ -945,7 +929,7 @@
       }
       OutputSectionBase<ELFT> *Sec;
       bool IsNew;
-      std::tie(Sec, IsNew) = Factory.create(C, getOutputSectionName(C));
+      std::tie(Sec, IsNew) = Factory.create(C, C->getOutputSectionName());
       if (IsNew) {
         OwningSections.emplace_back(Sec);
         OutputSections.push_back(Sec);
@@ -1149,19 +1133,6 @@
          Out<ELFT>::Dynamic->FiniArraySec);
 }
 
-static bool isAlpha(char C) {
-  return ('a' <= C && C <= 'z') || ('A' <= C && C <= 'Z') || C == '_';
-}
-
-static bool isAlnum(char C) { return isAlpha(C) || ('0' <= C && C <= '9'); }
-
-// Returns true if S is valid as a C language identifier.
-static bool isValidCIdentifier(StringRef S) {
-  if (S.empty() || !isAlpha(S[0]))
-    return false;
-  return std::all_of(S.begin() + 1, S.end(), isAlnum);
-}
-
 // If a section name is valid as a C identifier (which is rare because of
 // the leading '.'), linkers are expected to define __start_<secname> and
 // __stop_<secname> symbols. They are at beginning and end of the section,
Index: test/ELF/startstop-gccollect.s
===================================================================
--- test/ELF/startstop-gccollect.s
+++ test/ELF/startstop-gccollect.s
@@ -0,0 +1,43 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+
+## Default run: sections .foo and .bar exist in output
+# RUN: ld.lld %t -o %tout
+# RUN: llvm-objdump -d %tout | FileCheck -check-prefix=DISASM %s
+
+## Check that to have a reference to __start or __stop is 
+## sufficient condition to prevent the section from being garbage collected.
+# RUN: ld.lld %t --gc-sections -o %tout
+# RUN: llvm-objdump -d %tout | FileCheck -check-prefix=DISASM %s
+
+# DISASM:      _start:
+# DISASM-NEXT:    11000:       {{.*}}  callq   8
+# DISASM-NEXT:    11005:       {{.*}}  callq   3
+# DISASM-NEXT: Disassembly of section foo:
+# DISASM-NEXT: foo:
+# DISASM-NEXT:    1100a:       90      nop
+# DISASM-NEXT:    1100b:       90      nop
+# DISASM-NEXT:    1100c:       90      nop
+# DISASM-NEXT: Disassembly of section bar:
+# DISASM-NEXT: __start_bar:
+# DISASM-NEXT:    1100d:       90      nop
+# DISASM-NEXT:    1100e:       90      nop
+# DISASM-NEXT:    1100f:       90      nop
+
+.hidden __stop_foo
+.hidden __start_bar
+.global _start
+.text
+_start:
+ call __stop_foo
+ call __start_bar
+
+.section foo,"ax"
+ nop
+ nop
+ nop
+
+.section bar,"ax"
+ nop
+ nop
+ nop