Index: ELF/GdbIndex.h
===================================================================
--- ELF/GdbIndex.h
+++ ELF/GdbIndex.h
@@ -36,6 +36,8 @@
   llvm::Optional<llvm::RelocAddrEntry> findAux(const InputSectionBase &Sec,
                                                uint64_t Pos,
                                                ArrayRef<RelTy> Rels) const;
+  // Used to detect multiple debug sections with the same name.
+  llvm::StringSet<> Seen;
 
 public:
   explicit LLDDwarfObj(ObjFile<ELFT> *Obj);
Index: ELF/GdbIndex.cpp
===================================================================
--- ELF/GdbIndex.cpp
+++ ELF/GdbIndex.cpp
@@ -26,8 +26,13 @@
 
 template <class ELFT> LLDDwarfObj<ELFT>::LLDDwarfObj(ObjFile<ELFT> *Obj) {
   for (InputSectionBase *Sec : Obj->getSections()) {
-    if (!Sec)
+    if (!Sec || !Sec->Name.startswith(".debug"))
       continue;
+
+    if (!Seen.insert(Sec->Name).second)
+      error(toString(Obj) + ": multiple " + Sec->Name +
+            " sections are not supported");
+
     if (LLDDWARFSection *M = StringSwitch<LLDDWARFSection *>(Sec->Name)
                                  .Case(".debug_info", &InfoSection)
                                  .Case(".debug_ranges", &RangeSection)
Index: test/ELF/multiple-debug-sections.s
===================================================================
--- test/ELF/multiple-debug-sections.s
+++ test/ELF/multiple-debug-sections.s
@@ -0,0 +1,24 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t1.o
+# RUN: not ld.lld --gdb-index %t1.o -o %t 2>&1 | FileCheck %s
+# CHECK: error: {{.*}}.o: multiple .debug_info sections are not supported
+# CHECK: error: {{.*}}.o: multiple .debug_abbrev sections are not supported
+# CHECK: error: {{.*}}.o: multiple .debug_line sections are not supported
+
+.section  .debug_info,"",@progbits
+.quad 0
+
+.section  .debug_info,"G",@progbits,foo,comdat
+.quad 0
+
+.section  .debug_abbrev,"",@progbits
+.quad 0
+
+.section  .debug_abbrev,"G",@progbits,foo,comdat
+.quad 0
+
+.section  .debug_line,"",@progbits
+.quad 0
+
+.section  .debug_line,"G",@progbits,foo,comdat
+.quad 0