diff --git a/Modules/CMakeGenericSystem.cmake b/Modules/CMakeGenericSystem.cmake
index b5d30724a..6615849b2 100644
--- a/Modules/CMakeGenericSystem.cmake
+++ b/Modules/CMakeGenericSystem.cmake
@@ -50,6 +50,12 @@ IF(CMAKE_GENERATOR MATCHES "Makefiles")
   IF(DEFINED CMAKE_RULE_MESSAGES)
     SET_PROPERTY(GLOBAL PROPERTY RULE_MESSAGES ${CMAKE_RULE_MESSAGES})
   ENDIF(DEFINED CMAKE_RULE_MESSAGES)
+  IF(CMAKE_GENERATOR MATCHES "Unix Makefiles")
+    SET(CMAKE_EXPORT_COMPILE_COMMANDS OFF CACHE BOOL
+      "Enable/Disable output of compile commands during generation."
+      )
+    MARK_AS_ADVANCED(CMAKE_EXPORT_COMPILE_COMMANDS)
+  ENDIF(CMAKE_GENERATOR MATCHES "Unix Makefiles")
 ENDIF(CMAKE_GENERATOR MATCHES "Makefiles")
 
 
diff --git a/Source/cmGlobalUnixMakefileGenerator3.cxx b/Source/cmGlobalUnixMakefileGenerator3.cxx
index 55ff87e86..169d77d9d 100644
--- a/Source/cmGlobalUnixMakefileGenerator3.cxx
+++ b/Source/cmGlobalUnixMakefileGenerator3.cxx
@@ -30,6 +30,7 @@ cmGlobalUnixMakefileGenerator3::cmGlobalUnixMakefileGenerator3()
 #else
   this->UseLinkScript = true;
 #endif
+  this->CommandDatabase = NULL;
 }
 
 void cmGlobalUnixMakefileGenerator3
@@ -138,6 +139,17 @@ void cmGlobalUnixMakefileGenerator3
 }
 
 //----------------------------------------------------------------------------
+std::string EscapeJSON(const std::string& s) {
+  std::string result;
+  for (std::string::size_type i = 0; i < s.size(); ++i) {
+    if (s[i] == '"' || s[i] == '\\') {
+      result += '\\';
+    }
+    result += s[i];
+  }
+  return result;
+}
+
 void cmGlobalUnixMakefileGenerator3::Generate()
 {
   // first do superclass method
@@ -179,6 +191,35 @@ void cmGlobalUnixMakefileGenerator3::Generate()
   // write the main makefile
   this->WriteMainMakefile2();
   this->WriteMainCMakefile();
+
+  if (this->CommandDatabase != NULL) {
+    *this->CommandDatabase << std::endl << "]";
+    delete this->CommandDatabase;
+    this->CommandDatabase = NULL;
+  }
+}
+
+void cmGlobalUnixMakefileGenerator3::AddCXXCompileCommand(
+    const std::string &sourceFile, const std::string &workingDirectory,
+    const std::string &compileCommand) {
+  if (this->CommandDatabase == NULL)
+    {
+    std::string commandDatabaseName =
+      std::string(this->GetCMakeInstance()->GetHomeOutputDirectory())
+      + "/compile_commands.json";
+    this->CommandDatabase =
+      new cmGeneratedFileStream(commandDatabaseName.c_str());
+    *this->CommandDatabase << "[" << std::endl;
+    } else {
+    *this->CommandDatabase << "," << std::endl;
+    }
+  *this->CommandDatabase << "{" << std::endl
+      << "  \"directory\": \"" << EscapeJSON(workingDirectory) << "\","
+      << std::endl
+      << "  \"command\": \"" << EscapeJSON(compileCommand) << "\","
+      << std::endl
+      << "  \"file\": \"" << EscapeJSON(sourceFile) << "\""
+      << std::endl << "}";
 }
 
 void cmGlobalUnixMakefileGenerator3::WriteMainMakefile2()
diff --git a/Source/cmGlobalUnixMakefileGenerator3.h b/Source/cmGlobalUnixMakefileGenerator3.h
index 11174d7fb..d21d5b957 100644
--- a/Source/cmGlobalUnixMakefileGenerator3.h
+++ b/Source/cmGlobalUnixMakefileGenerator3.h
@@ -112,6 +112,10 @@ public:
   /** Record per-target progress information.  */
   void RecordTargetProgress(cmMakefileTargetGenerator* tg);
 
+  void AddCXXCompileCommand(const std::string &sourceFile,
+                            const std::string &workingDirectory,
+                            const std::string &compileCommand);
+
 protected:
   void WriteMainMakefile2();
   void WriteMainCMakefile();
@@ -176,6 +180,8 @@ protected:
   size_t CountProgressMarksInTarget(cmTarget* target,
                                     std::set<cmTarget*>& emitted);
   size_t CountProgressMarksInAll(cmLocalUnixMakefileGenerator3* lg);
+
+  cmGeneratedFileStream *CommandDatabase;
 };
 
 #endif
diff --git a/Source/cmMakefileTargetGenerator.cxx b/Source/cmMakefileTargetGenerator.cxx
index 69320dac4..d0df8f076 100644
--- a/Source/cmMakefileTargetGenerator.cxx
+++ b/Source/cmMakefileTargetGenerator.cxx
@@ -249,32 +249,56 @@ void cmMakefileTargetGenerator::WriteCommonCodeRules()
 }
 
 //----------------------------------------------------------------------------
-void cmMakefileTargetGenerator::WriteTargetLanguageFlags()
+std::string cmMakefileTargetGenerator::GetFlags(const std::string &l)
 {
-  // write language flags for target
-  std::set<cmStdString> languages;
-  this->Target->GetLanguages(languages);
-    // put the compiler in the rules.make file so that if it changes
-  // things rebuild
-  for(std::set<cmStdString>::const_iterator l = languages.begin();
-      l != languages.end(); ++l)
+  ByLanguageMap::iterator i = this->FlagsByLanguage.find(l);
+  if (i == this->FlagsByLanguage.end())
     {
-    cmStdString compiler = "CMAKE_";
-    compiler += *l;
-    compiler += "_COMPILER";
-    *this->FlagFileStream << "# compile " << l->c_str() << " with " << 
-      this->Makefile->GetSafeDefinition(compiler.c_str()) << "\n";
-    }
-
-  for(std::set<cmStdString>::const_iterator l = languages.begin();
-      l != languages.end(); ++l)
-    {
-    const char *lang = l->c_str();
     std::string flags;
-    std::string defines;
+    const char *lang = l.c_str();
+
     bool shared = ((this->Target->GetType() == cmTarget::SHARED_LIBRARY) ||
                    (this->Target->GetType() == cmTarget::MODULE_LIBRARY));
 
+    // Add language feature flags.
+    this->AddFeatureFlags(flags, lang);
+
+    this->LocalGenerator->AddArchitectureFlags(flags, this->Target,
+                                               lang, this->ConfigName);
+
+    // Fortran-specific flags computed for this target.
+    if(l == "Fortran")
+      {
+      this->AddFortranFlags(flags);
+      }
+
+    // Add shared-library flags if needed.
+    this->LocalGenerator->AddSharedFlags(flags, lang, shared);
+
+    // Add include directory flags.
+    this->AddIncludeFlags(flags, lang);
+
+    // Append old-style preprocessor definition flags.
+    this->LocalGenerator->
+      AppendFlags(flags, this->Makefile->GetDefineFlags());
+
+    // Add include directory flags.
+    this->LocalGenerator->
+      AppendFlags(flags,this->GetFrameworkFlags().c_str());
+
+    ByLanguageMap::value_type entry(l, flags);
+    i = this->FlagsByLanguage.insert(entry).first;
+    }
+  return i->second;
+}
+
+std::string cmMakefileTargetGenerator::GetDefines(const std::string &l)
+{
+  ByLanguageMap::iterator i = this->DefinesByLanguage.find(l);
+  if (i == this->DefinesByLanguage.end())
+    {
+    std::string defines;
+    const char *lang = l.c_str();
     // Add the export symbol definition for shared library objects.
     if(const char* exportMacro = this->Target->GetExportMacro())
       {
@@ -294,40 +318,41 @@ void cmMakefileTargetGenerator::WriteTargetLanguageFlags()
     this->LocalGenerator->AppendDefines
       (defines, this->Target->GetProperty(defPropName.c_str()), lang);
 
-    // Add language feature flags.
-    this->AddFeatureFlags(flags, lang);
+    ByLanguageMap::value_type entry(l, defines);
+    i = this->DefinesByLanguage.insert(entry).first;
+    }
+  return i->second;
+}
 
-    this->LocalGenerator->AddArchitectureFlags(flags, this->Target,
-                                               lang, this->ConfigName);
+void cmMakefileTargetGenerator::WriteTargetLanguageFlags()
+{
+  // write language flags for target
+  std::set<cmStdString> languages;
+  this->Target->GetLanguages(languages);
+    // put the compiler in the rules.make file so that if it changes
+  // things rebuild
+  for(std::set<cmStdString>::const_iterator l = languages.begin();
+      l != languages.end(); ++l)
+    {
+    cmStdString compiler = "CMAKE_";
+    compiler += *l;
+    compiler += "_COMPILER";
+    *this->FlagFileStream << "# compile " << l->c_str() << " with " <<
+      this->Makefile->GetSafeDefinition(compiler.c_str()) << "\n";
+    }
 
-    // Fortran-specific flags computed for this target.
-    if(*l == "Fortran")
-      {
-      this->AddFortranFlags(flags);
-      }
-
-    // Add shared-library flags if needed.
-    this->LocalGenerator->AddSharedFlags(flags, lang, shared);
-
-    // Add include directory flags.
-    this->AddIncludeFlags(flags, lang);
-
-    // Append old-style preprocessor definition flags.
-    this->LocalGenerator->
-      AppendFlags(flags, this->Makefile->GetDefineFlags());
-
-    // Add include directory flags.
-    this->LocalGenerator->
-      AppendFlags(flags,this->GetFrameworkFlags().c_str());
-
-    *this->FlagFileStream << lang << "_FLAGS = " << flags << "\n\n";
-    *this->FlagFileStream << lang << "_DEFINES = " << defines << "\n\n";
+  for(std::set<cmStdString>::const_iterator l = languages.begin();
+      l != languages.end(); ++l)
+    {
+    *this->FlagFileStream << *l << "_FLAGS = " << this->GetFlags(*l) << "\n\n";
+    *this->FlagFileStream << *l << "_DEFINES = " << this->GetDefines(*l) <<
+      "\n\n";
     }
 
   // Add target-specific flags.
   if(this->Target->GetProperty("COMPILE_FLAGS"))
     {
-    std::string flags;    
+    std::string flags;
     this->LocalGenerator->AppendFlags
       (flags, this->Target->GetProperty("COMPILE_FLAGS"));
     *this->FlagFileStream << "# TARGET_FLAGS = " << flags << "\n\n";
@@ -641,6 +666,9 @@ cmMakefileTargetGenerator
   vars.Flags = flags.c_str();
   vars.Defines = defines.c_str();
 
+  bool lang_is_c_or_cxx = ((strcmp(lang, "C") == 0) ||
+                           (strcmp(lang, "CXX") == 0));
+
   // Construct the compile rules.
   {
   std::string compileRuleVar = "CMAKE_";
@@ -651,6 +679,23 @@ cmMakefileTargetGenerator
   std::vector<std::string> compileCommands;
   cmSystemTools::ExpandListArgument(compileRule, compileCommands);
 
+  if (this->Makefile->IsOn("CMAKE_EXPORT_COMPILE_COMMANDS") &&
+      lang_is_c_or_cxx && compileCommands.size() == 1)
+    {
+    std::string compileCommand = compileCommands[0];
+    this->LocalGenerator->ExpandRuleVariables(compileCommand, vars);
+    std::string workingDirectory =
+      this->LocalGenerator->Convert(
+        this->Makefile->GetStartOutputDirectory(), cmLocalGenerator::FULL);
+    compileCommand.replace(compileCommand.find(langFlags),
+                           langFlags.size(), this->GetFlags(lang));
+    std::string langDefines = std::string("$(") + lang + "_DEFINES)";
+    compileCommand.replace(compileCommand.find(langDefines),
+                           langDefines.size(), this->GetDefines(lang));
+    this->GlobalGenerator->AddCXXCompileCommand(
+      source.GetFullPath(), workingDirectory, compileCommand);
+    }
+
   // Expand placeholders in the commands.
   for(std::vector<std::string>::iterator i = compileCommands.begin();
       i != compileCommands.end(); ++i)
@@ -691,8 +736,6 @@ cmMakefileTargetGenerator
       }
     }
 
-  bool lang_is_c_or_cxx = ((strcmp(lang, "C") == 0) ||
-                           (strcmp(lang, "CXX") == 0));
   bool do_preprocess_rules = lang_is_c_or_cxx &&
     this->LocalGenerator->GetCreatePreprocessedSourceRules();
   bool do_assembly_rules = lang_is_c_or_cxx &&
diff --git a/Source/cmMakefileTargetGenerator.h b/Source/cmMakefileTargetGenerator.h
index bd26795d3..b68f8bf3b 100644
--- a/Source/cmMakefileTargetGenerator.h
+++ b/Source/cmMakefileTargetGenerator.h
@@ -216,6 +216,12 @@ protected:
   std::string MacContentDirectory;
   std::set<cmStdString> MacContentFolders;
 
+  typedef std::map<cmStdString, cmStdString> ByLanguageMap;
+  std::string GetFlags(const std::string &l);
+  ByLanguageMap FlagsByLanguage;
+  std::string GetDefines(const std::string &l);
+  ByLanguageMap DefinesByLanguage;
+
   // Target-wide Fortran module output directory.
   bool FortranModuleDirectoryComputed;
   std::string FortranModuleDirectory;
diff --git a/Source/cmSystemTools.cxx b/Source/cmSystemTools.cxx
index b99205485..dc63568bf 100644
--- a/Source/cmSystemTools.cxx
+++ b/Source/cmSystemTools.cxx
@@ -445,6 +445,13 @@ public:
       args.push_back(*arg);
       }
     }
+  void Store(std::vector<cmStdString>& args) const
+    {
+    for(char** arg = this->ArgV; arg && *arg; ++arg)
+      {
+      args.push_back(*arg);
+      }
+    }
 };
 
 //----------------------------------------------------------------------------
@@ -456,6 +463,15 @@ void cmSystemTools::ParseUnixCommandLine(const char* command,
   argv.Store(args);
 }
 
+//----------------------------------------------------------------------------
+void cmSystemTools::ParseUnixCommandLine(const char* command,
+                                         std::vector<cmStdString>& args)
+{
+  // Invoke the underlying parser.
+  cmSystemToolsArgV argv = cmsysSystem_Parse_CommandForUnix(command, 0);
+  argv.Store(args);
+}
+
 std::string cmSystemTools::EscapeWindowsShellArgument(const char* arg,
                                                       int shell_flags)
 {
diff --git a/Source/cmSystemTools.h b/Source/cmSystemTools.h
index 78b9abf2f..fc85d4afa 100644
--- a/Source/cmSystemTools.h
+++ b/Source/cmSystemTools.h
@@ -237,6 +237,8 @@ public:
   /** Parse arguments out of a unix command line string.  */
   static void ParseUnixCommandLine(const char* command,
                                    std::vector<std::string>& args);
+  static void ParseUnixCommandLine(const char* command,
+                                   std::vector<cmStdString>& args);
 
   /** Compute an escaped version of the given argument for use in a
       windows shell.  See kwsys/System.h.in for details.  */
diff --git a/Tests/CMakeLib/CMakeLists.txt b/Tests/CMakeLib/CMakeLists.txt
index bda2fa5f8..41bf03437 100644
--- a/Tests/CMakeLib/CMakeLists.txt
+++ b/Tests/CMakeLib/CMakeLists.txt
@@ -30,3 +30,8 @@ endif()
 foreach(test ${CMakeLib_TESTS})
   add_test(CMakeLib.${test} CMakeLibTests ${test})
 endforeach()
+
+if(TEST_CompileCommandOutput)
+  add_executable(runcompilecommands run_compile_commands.cxx)
+  target_link_libraries(runcompilecommands CMakeLib)
+endif()
diff --git a/Tests/CMakeLib/run_compile_commands.cxx b/Tests/CMakeLib/run_compile_commands.cxx
new file mode 100644
index 000000000..3f141c537
--- /dev/null
+++ b/Tests/CMakeLib/run_compile_commands.cxx
@@ -0,0 +1,141 @@
+#include "cmSystemTools.h"
+
+class CompileCommandParser {
+public:
+  class CommandType: public std::map<cmStdString, cmStdString>
+  {
+  public:
+    cmStdString const& at(cmStdString const& k) const
+      {
+      const_iterator i = this->find(k);
+      if(i != this->end()) { return i->second; }
+      static cmStdString emptyString;
+      return emptyString;
+      }
+  };
+  typedef std::vector<CommandType> TranslationUnitsType;
+
+  CompileCommandParser(std::ifstream *input)
+  {
+    this->Input = input;
+  }
+
+  void Parse()
+  {
+    NextNonWhitespace();
+    ParseTranslationUnits();
+  }
+
+  const TranslationUnitsType& GetTranslationUnits()
+  {
+    return this->TranslationUnits;
+  }
+
+private:
+  void ParseTranslationUnits()
+  {
+    this->TranslationUnits = TranslationUnitsType();
+    ExpectOrDie('[', "at start of compile command file");
+    do
+      {
+      ParseTranslationUnit();
+      this->TranslationUnits.push_back(this->Command);
+      } while(Expect(','));
+    ExpectOrDie(']', "at end of array");
+  }
+
+  void ParseTranslationUnit()
+  {
+    this->Command = CommandType();
+    if(!Expect('{')) return;
+    if(Expect('}')) return;
+    do
+      {
+      ParseString();
+      std::string name = this->String;
+      ExpectOrDie(':', "between name and value");
+      ParseString();
+      std::string value = this->String;
+      this->Command[name] = value;
+      } while(Expect(','));
+    ExpectOrDie('}', "at end of object");
+  }
+
+  void ParseString()
+  {
+    this->String.clear();
+    if(!Expect('"')) return;
+    while (!Expect('"'))
+      {
+      Expect('\\');
+      this->String.push_back(C);
+      Next();
+      }
+  }
+
+  bool Expect(char c)
+  {
+    if(this->C == c)
+      {
+      NextNonWhitespace();
+      return true;
+      }
+    return false;
+  }
+
+  void ExpectOrDie(char c, const std::string & message)
+  {
+    if (!Expect(c))
+      ErrorExit(std::string("'") + c + "' expected " + message + ".");
+  }
+
+  void NextNonWhitespace()
+  {
+    do { Next(); } while (IsWhitespace());
+  }
+
+  void Next()
+  {
+    this->C = char(Input->get());
+    if (this->Input->bad()) ErrorExit("Unexpected end of file.");
+  }
+
+  void ErrorExit(const std::string &message) {
+    std::cout << "ERROR: " << message;
+    exit(1);
+  }
+
+  bool IsWhitespace()
+  {
+    return (this->C == ' ' || this->C == '\t' ||
+            this->C == '\n' || this->C == '\r');
+  }
+
+  char C;
+  TranslationUnitsType TranslationUnits;
+  CommandType Command;
+  std::string String;
+  std::ifstream *Input;
+};
+
+int main ()
+{
+  std::ifstream file("compile_commands.json");
+  CompileCommandParser parser(&file);
+  parser.Parse();
+  for(CompileCommandParser::TranslationUnitsType::const_iterator
+      it = parser.GetTranslationUnits().begin(),
+      end = parser.GetTranslationUnits().end(); it != end; ++it)
+    {
+    std::vector<cmStdString> command;
+    cmSystemTools::ParseUnixCommandLine(it->at("command").c_str(), command);
+    if (!cmSystemTools::RunSingleCommand(
+            command, 0, 0, it->at("directory").c_str()))
+      {
+      std::cout << "ERROR: Failed to run command \""
+                << command[0] << "\"" << std::endl;
+      exit(1);
+      }
+    }
+  return 0;
+}
diff --git a/Tests/CMakeLists.txt b/Tests/CMakeLists.txt
index 157814e05..e9aed1650 100644
--- a/Tests/CMakeLists.txt
+++ b/Tests/CMakeLists.txt
@@ -11,6 +11,7 @@ MACRO(ADD_TEST_MACRO NAME COMMAND)
     --build-generator ${CMAKE_TEST_GENERATOR}
     --build-makeprogram ${CMAKE_TEST_MAKEPROGRAM}
     --build-project ${proj}
+    ${${NAME}_EXTRA_OPTIONS}
     --test-command ${COMMAND} ${ARGN})
   LIST(APPEND TEST_BUILD_DIRS "${CMake_BINARY_DIR}/Tests/${dir}")
 ENDMACRO(ADD_TEST_MACRO)
@@ -39,6 +40,10 @@ CONFIGURE_FILE(${CMake_SOURCE_DIR}/Tests/EnforceConfig.cmake.in
 
 # Testing
 IF(BUILD_TESTING)
+  IF("${CMAKE_TEST_GENERATOR}" MATCHES "Unix Makefiles")
+    SET(TEST_CompileCommandOutput 1)
+  ENDIF()
+
   ADD_SUBDIRECTORY(CMakeLib)
 
   # Collect a list of all test build directories.
@@ -2031,6 +2036,13 @@ ${CMake_BINARY_DIR}/bin/cmake -DVERSION=master -P ${CMake_SOURCE_DIR}/Utilities/
     ENDIF()
     SET_TESTS_PROPERTIES(Contracts.${project} PROPERTIES TIMEOUT ${timeout})
   ENDFOREACH()
+
+  IF(TEST_CompileCommandOutput)
+    SET(CompileCommandOutput_EXTRA_OPTIONS
+      --build-options -DMAKE_SUPPORTS_SPACES=${MAKE_IS_GNU})
+    ADD_TEST_MACRO(CompileCommandOutput
+      "${CMake_BINARY_DIR}/Tests/CMakeLib/runcompilecommands")
+  ENDIF()
 ENDIF(BUILD_TESTING)
 
 SUBDIRS(CMakeTests)
diff --git a/Tests/CompileCommandOutput/CMakeLists.txt b/Tests/CompileCommandOutput/CMakeLists.txt
new file mode 100644
index 000000000..bd8e305c2
--- /dev/null
+++ b/Tests/CompileCommandOutput/CMakeLists.txt
@@ -0,0 +1,16 @@
+# a simple C only test case
+cmake_minimum_required (VERSION 2.6)
+project (CompileCommandOutput CXX)
+
+SET(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+set(CMAKE_DEBUG_POSTFIX "_test_debug_postfix")
+IF(MAKE_SUPPORTS_SPACES)
+  SET(test1_srcs "file with spaces.cxx")
+ELSE()
+  SET(test1_srcs "file_with_underscores.cxx")
+ENDIF()
+ADD_LIBRARY(test1 STATIC ${test1_srcs})
+ADD_LIBRARY(test2 SHARED "../CompileCommandOutput/relative.cxx")
+INCLUDE_DIRECTORIES(${CompileCommandOutput_SOURCE_DIR}/../../Source)
+ADD_EXECUTABLE(CompileCommandOutput compile_command_output.cxx)
+TARGET_LINK_LIBRARIES(CompileCommandOutput test1 test2)
diff --git a/Tests/CompileCommandOutput/compile_command_output.cxx b/Tests/CompileCommandOutput/compile_command_output.cxx
new file mode 100644
index 000000000..145a06426
--- /dev/null
+++ b/Tests/CompileCommandOutput/compile_command_output.cxx
@@ -0,0 +1,9 @@
+#include "file_with_underscores.h"
+#include "relative.h"
+
+int main (int argc, char** argv)
+{
+  file_with_underscores();
+  relative();
+  return 0;
+}
diff --git a/Tests/CompileCommandOutput/file with spaces.cxx b/Tests/CompileCommandOutput/file with spaces.cxx
new file mode 100644
index 000000000..554e176e4
--- /dev/null
+++ b/Tests/CompileCommandOutput/file with spaces.cxx	
@@ -0,0 +1 @@
+#include "file_with_underscores.cxx"
diff --git a/Tests/CompileCommandOutput/file_with_underscores.cxx b/Tests/CompileCommandOutput/file_with_underscores.cxx
new file mode 100644
index 000000000..4f42ccf56
--- /dev/null
+++ b/Tests/CompileCommandOutput/file_with_underscores.cxx
@@ -0,0 +1,3 @@
+#include "file_with_underscores.h"
+
+void file_with_underscores() {}
diff --git a/Tests/CompileCommandOutput/file_with_underscores.h b/Tests/CompileCommandOutput/file_with_underscores.h
new file mode 100644
index 000000000..0d73e3159
--- /dev/null
+++ b/Tests/CompileCommandOutput/file_with_underscores.h
@@ -0,0 +1 @@
+void file_with_underscores();
diff --git a/Tests/CompileCommandOutput/relative.cxx b/Tests/CompileCommandOutput/relative.cxx
new file mode 100644
index 000000000..eae11e226
--- /dev/null
+++ b/Tests/CompileCommandOutput/relative.cxx
@@ -0,0 +1,3 @@
+#include "relative.h"
+
+void relative() {}
diff --git a/Tests/CompileCommandOutput/relative.h b/Tests/CompileCommandOutput/relative.h
new file mode 100644
index 000000000..ddfe5519b
--- /dev/null
+++ b/Tests/CompileCommandOutput/relative.h
@@ -0,0 +1,11 @@
+#if defined(_WIN32)
+# ifdef test2_EXPORTS
+#  define TEST2_EXPORT __declspec(dllexport)
+# else
+#  define TEST2_EXPORT __declspec(dllimport)
+# endif
+#else
+# define TEST2_EXPORT
+#endif
+
+TEST2_EXPORT void relative();