Index: lld/trunk/COFF/Chunks.cpp
===================================================================
--- lld/trunk/COFF/Chunks.cpp
+++ lld/trunk/COFF/Chunks.cpp
@@ -351,7 +351,12 @@
           check(File->getCOFFObj()->getSymbol(Rel.SymbolTableIndex));
       StringRef Name;
       File->getCOFFObj()->getSymbolName(Sym, Name);
-      error("relocation against symbol in discarded section: " + Name);
+
+      // MinGW mode object files (built by GCC) can have leftover sections
+      // with relocations against discarded comdat sections. Such sections
+      // are left as is, with relocations untouched.
+      if (!Config->MinGW)
+        error("relocation against symbol in discarded section: " + Name);
       continue;
     }
     // Get the output section of the symbol for this relocation.  The output
Index: lld/trunk/test/COFF/Inputs/comdat-jumptable2.s
===================================================================
--- lld/trunk/test/COFF/Inputs/comdat-jumptable2.s
+++ lld/trunk/test/COFF/Inputs/comdat-jumptable2.s
@@ -0,0 +1,35 @@
+        .section .text@comdatfunc, "x"
+        .linkonce discard
+        .globl comdatfunc
+comdatfunc:
+        leaq .Ljumptable(%rip), %rax
+        movslq (%rax, %rcx, 4), %rcx
+        addq %rcx, %rax
+        jmp *%rax
+
+        .section .rdata, "dr"
+        .long 0xcccccccc
+.Ljumptable:
+        .long .Ltail1-.Ljumptable
+        .long .Ltail2-.Ljumptable
+        .long .Ltail3-.Ljumptable
+        .long 0xdddddddd
+
+        .section .text@comdatfunc, "x"
+# If assembled with binutils, the following line can be kept in:
+#       .linkonce discard
+.Ltail1:
+        movl $1, %eax
+        ret
+.Ltail2:
+        movl $2, %eax
+        ret
+.Ltail3:
+        movl $3, %eax
+        ret
+
+        .text
+        .globl otherfunc
+otherfunc:
+        call comdatfunc
+        ret
Index: lld/trunk/test/COFF/comdat-jumptable.s
===================================================================
--- lld/trunk/test/COFF/comdat-jumptable.s
+++ lld/trunk/test/COFF/comdat-jumptable.s
@@ -0,0 +1,70 @@
+# REQUIRES: x86
+# RUN: llvm-mc -triple=x86_64-windows-gnu %s -filetype=obj -o %t1.obj
+# RUN: llvm-mc -triple=x86_64-windows-gnu %S/Inputs/comdat-jumptable2.s -filetype=obj -o %t2.obj
+
+# RUN: llvm-objdump -s %t1.obj | FileCheck --check-prefix=OBJ1 %s
+# RUN: llvm-objdump -s %t2.obj | FileCheck --check-prefix=OBJ2 %s
+
+# RUN: lld-link -lldmingw -entry:main %t1.obj %t2.obj -out:%t.exe
+# RUN: llvm-objdump -s %t.exe | FileCheck --check-prefix=EXE %s
+
+# Test linking cases where comdat functions have an associated jump table
+# in a non-comdat rdata (which GCC produces for functions with jump tables).
+# In these cases, ld.bfd keeps all rdata sections, but the relocations that
+# refer to discarded comdat sections just are emitted as they were originally.
+
+# In real scenarios, the jump table .rdata section should be identical across
+# all object files; here it is different to illustrate more clearly what
+# the linker actually does.
+
+# OBJ1: Contents of section .rdata:
+# OBJ1:  0000 aaaaaaaa 14000000 1e000000 28000000
+# OBJ1:  0010 bbbbbbbb
+
+# OBJ2: Contents of section .rdata:
+# OBJ2:  0000 cccccccc 14000000 1e000000 28000000
+# OBJ2:  0010 dddddddd
+
+# EXE: Contents of section .rdata:
+# EXE:  140002000 aaaaaaaa 0c100000 12100000 18100000
+# EXE:  140002010 bbbbbbbb cccccccc 14000000 1e000000
+# EXE:  140002020 28000000 dddddddd
+
+
+        .section .text@comdatfunc, "x"
+        .linkonce discard
+        .globl comdatfunc
+comdatfunc:
+        leaq .Ljumptable(%rip), %rax
+        movslq (%rax, %rcx, 4), %rcx
+        addq %rcx, %rax
+        jmp *%rax
+
+        .section .rdata, "dr"
+        .long 0xaaaaaaaa
+.Ljumptable:
+        .long .Ltail1-.Ljumptable
+        .long .Ltail2-.Ljumptable
+        .long .Ltail3-.Ljumptable
+        .long 0xbbbbbbbb
+
+        .section .text@comdatfunc, "x"
+# If assembled with binutils, the following line can be kept in:
+#       .linkonce discard
+.Ltail1:
+        movl $1, %eax
+        ret
+.Ltail2:
+        movl $2, %eax
+        ret
+.Ltail3:
+        movl $3, %eax
+        ret
+
+
+        .text
+        .globl main
+main:
+        call comdatfunc
+        call otherfunc
+        ret