Index: lib/Sema/SemaDecl.cpp
===================================================================
--- lib/Sema/SemaDecl.cpp
+++ lib/Sema/SemaDecl.cpp
@@ -1683,15 +1683,51 @@
     return nullptr;
   }
 
+  //get the file buffer
+  FileID FileID = SourceMgr.getFileID(Loc);
+  llvm::MemoryBuffer* FileBuf = SourceMgr.getBuffer(FileID);
+  SourceLocation LastIncludeLoc = SourceMgr.getLocForStartOfFile(FileID);
+
+  //Find the Location of the last #include directive in the file
+  Lexer IncludeLexer(FileID,FileBuf,SourceMgr,LangOpts);
+  while (1) {
+      Token Tok;
+      IncludeLexer.LexFromRawLexer(Tok);
+      if (Tok.is(tok::eof))
+          break;
+      if (Tok.is(tok::hash)){
+          IncludeLexer.LexFromRawLexer(Tok);
+          if(Tok.getRawIdentifier() == "include" && Tok.getLocation().isValid())
+                LastIncludeLoc = Tok.getLocation();
+      }
+  }
+
+
+  //Get the location of the line after the last #include directive
+  PresumedLoc PLoc = SourceMgr.getPresumedLoc(LastIncludeLoc);
+  SourceLocation FixitLoc = SourceMgr.translateLineCol(FileID,PLoc.getLine()+1,PLoc.getColumn());
+  if (FixitLoc.isInvalid()){
+      FixitLoc = LastIncludeLoc;
+  }
+
+
+
   if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(ID)) {
     Diag(Loc, diag::ext_implicit_lib_function_decl)
       << Context.BuiltinInfo.GetName(ID)
       << R;
+    //Build 'insert missing header' string
+    std::string FixitString = "#include <";
+    FixitString.append(Context.BuiltinInfo.getHeaderName(ID));
+    FixitString.append(">");
+    StringRef FixitStringRef(FixitString.c_str());
+
     if (Context.BuiltinInfo.getHeaderName(ID) &&
         !Diags.isIgnored(diag::ext_implicit_lib_function_decl, Loc))
-      Diag(Loc, diag::note_include_header_or_declare)
+      Diag(FixitLoc, diag::note_include_header_or_declare)
           << Context.BuiltinInfo.getHeaderName(ID)
-          << Context.BuiltinInfo.GetName(ID);
+          << Context.BuiltinInfo.GetName(ID)
+          << FixItHint::CreateInsertion(FixitLoc, FixitStringRef);
   }
 
   DeclContext *Parent = Context.getTranslationUnitDecl();
Index: test/Sema/Inputs/dummyheader.h
===================================================================
--- /dev/null
+++ test/Sema/Inputs/dummyheader.h
@@ -0,0 +1 @@
+//this is a dummy header used by implicit-builtin-include-fixit.c
Index: test/Sema/implicit-builtin-decl.c
===================================================================
--- test/Sema/implicit-builtin-decl.c
+++ test/Sema/implicit-builtin-decl.c
@@ -3,7 +3,7 @@
 
 void f() {
   int *ptr = malloc(sizeof(int) * 10); // expected-warning{{implicitly declaring library function 'malloc' with type}} \
-  // expected-note{{include the header <stdlib.h> or explicitly provide a declaration for 'malloc'}} \
+  // expected-note@-3{{include the header <stdlib.h> or explicitly provide a declaration for 'malloc'}} \
   // expected-note{{'malloc' is a builtin with type 'void *}}
 }
 
Index: test/Sema/implicit-builtin-include-fixit.c
===================================================================
--- /dev/null
+++ test/Sema/implicit-builtin-include-fixit.c
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wdocumentation -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
+
+#include "Inputs/dummyheader.h"/*dummy header to test implicit declaration fixit*/
+
+void f() {
+  int *ptr = malloc(sizeof(int) * 10); // expected-warning{{implicitly declaring library function 'malloc' with type}}\
+  // expected-note@-2{{include the header <stdlib.h> or explicitly provide a declaration for 'malloc'}}  
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:1-[[@LINE-4]]:1}:"#include <stdlib.h>"
+}