diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -1300,6 +1300,7 @@
   TempDISubroutineType clone() const { return cloneImpl(); }
 
   uint8_t getCC() const { return CC; }
+  void setCC(uint8_t NewCC) { CC = NewCC; }
 
   DITypeRefArray getTypeArray() const {
     return cast_or_null<MDTuple>(getRawTypeArray());
diff --git a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -23,6 +23,7 @@
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/DIBuilder.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRBuilder.h"
@@ -1083,6 +1084,15 @@
   for (auto MD : MDs)
     NF->addMetadata(MD.first, *MD.second);
 
+  // If all the return values are removed, add DW_CC_nocall to DISubroutineType
+  // so that debuggers will know it is not safe to call this function or try to
+  // interpret the return value.
+  // FIXME: Should we add DW_CC_nocall simply when NFTy != FTy i.e. whenever
+  // an unused return value or an argument is removed?
+  if (!RetTy->isVoidTy() && NRetTy->isVoidTy() && NF->getSubprogram())
+    // Change CallingConvention to DW_CC_nocall
+    NF->getSubprogram()->getType()->setCC(llvm::dwarf::DW_CC_nocall);
+
   // Now that the old function is dead, delete it.
   F->eraseFromParent();
 
diff --git a/llvm/test/Transforms/DeadArgElim/2010-04-30-DbgInfo.ll b/llvm/test/Transforms/DeadArgElim/2010-04-30-DbgInfo.ll
--- a/llvm/test/Transforms/DeadArgElim/2010-04-30-DbgInfo.ll
+++ b/llvm/test/Transforms/DeadArgElim/2010-04-30-DbgInfo.ll
@@ -1,23 +1,27 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature
-; RUN: opt -S -passes=deadargelim < %s | FileCheck %s
+; RUN: opt < %s -S -passes=deadargelim > %t
+; RUN: cat %t | FileCheck %s
+; Test whether DW_CC_nocall calling convention is added when return values are removed and return type changed to void.
+; RUN: cat %t | grep "define internal fastcc void \@add_name_internal"
+; RUN: cat %t | grep DW_CC_nocall
 
 @.str = private constant [1 x i8] zeroinitializer, align 1 ; <[1 x i8]*> [#uses=1]
 
-define i8* @vfs_addname(i8* %name, i32 %len, i32 %hash, i32 %flags) nounwind ssp {
+define i8* @vfs_addname(i8* %name, i32 %len, i32 %hash, i32 %flags) nounwind ssp !dbg !1 {
 ;
 entry:
   call void @llvm.dbg.value(metadata i8* %name, metadata !0, metadata !DIExpression()), !dbg !DILocation(scope: !1)
   call void @llvm.dbg.value(metadata i32 %len, metadata !10, metadata !DIExpression()), !dbg !DILocation(scope: !1)
   call void @llvm.dbg.value(metadata i32 %hash, metadata !11, metadata !DIExpression()), !dbg !DILocation(scope: !1)
   call void @llvm.dbg.value(metadata i32 %flags, metadata !12, metadata !DIExpression()), !dbg !DILocation(scope: !1)
-; CHECK:  call fastcc i8* @add_name_internal(i8* %name, i32 %hash) [[NUW:#[0-9]+]], !dbg !{{[0-9]+}}
+; CHECK:  call fastcc void @add_name_internal(i8* %name, i32 %hash) [[NUW:#[0-9]+]], !dbg !{{[0-9]+}}
   %0 = call fastcc i8* @add_name_internal(i8* %name, i32 %len, i32 %hash, i8 zeroext 0, i32 %flags) nounwind, !dbg !13 ; <i8*> [#uses=1]
-  ret i8* %0, !dbg !13
+  ret i8* %name, !dbg !13
 }
 
 declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
 
-define internal fastcc i8* @add_name_internal(i8* %name, i32 %len, i32 %hash, i8 zeroext %extra, i32 %flags) noinline nounwind ssp {
+define internal fastcc i8* @add_name_internal(i8* %name, i32 %len, i32 %hash, i8 zeroext %extra, i32 %flags) noinline nounwind ssp !dbg !16 {
 ;
 entry:
   call void @llvm.dbg.value(metadata i8* %name, metadata !15, metadata !DIExpression()), !dbg !DILocation(scope: !16)