cmSystemTools: Teach RunSingleCommand to separate stdout and stderr

Extend the RunSingleCommand signature to capture stdout and stderr
separately.  Allow both to be captured to the same std::string
to preserve existing behavior.  Update all call sites to do this
so that this refactoring does not introduce functional changes.

23 files changed, 110 insertions, 69 deletions

diff --git a/Source/CPack/IFW/cmCPackIFWGenerator.cxx b/Source/CPack/IFW/cmCPackIFWGenerator.cxx
index 7f06e2d..0439ff6 100644
--- a/Source/CPack/IFW/cmCPackIFWGenerator.cxx
+++ b/Source/CPack/IFW/cmCPackIFWGenerator.cxx
@@ -92,7 +92,8 @@ int cmCPackIFWGenerator::PackageFiles()
     cmCPackLogger(cmCPackLog::LOG_OUTPUT,
                   "- Generate repository" << std::endl);
     bool res = cmSystemTools::RunSingleCommand(
-      ifwCmd.c_str(), &output, &retVal, 0, this->GeneratorVerbose, 0);
+      ifwCmd.c_str(), &output, &output,
+      &retVal, 0, this->GeneratorVerbose, 0);
     if ( !res || retVal )
       {
       cmGeneratedFileStream ofs(ifwTmpFile.c_str());
@@ -176,7 +177,8 @@ int cmCPackIFWGenerator::PackageFiles()
   int retVal = 1;
   cmCPackLogger(cmCPackLog::LOG_OUTPUT, "- Generate package" << std::endl);
   bool res = cmSystemTools::RunSingleCommand(
-    ifwCmd.c_str(), &output, &retVal, 0, this->GeneratorVerbose, 0);
+    ifwCmd.c_str(), &output, &output,
+    &retVal, 0, this->GeneratorVerbose, 0);
   if ( !res || retVal )
     {
     cmGeneratedFileStream ofs(ifwTmpFile.c_str());
diff --git a/Source/CPack/WiX/cmCPackWIXGenerator.cxx b/Source/CPack/WiX/cmCPackWIXGenerator.cxx
index 99eabf2..b3eb7b2 100644
--- a/Source/CPack/WiX/cmCPackWIXGenerator.cxx
+++ b/Source/CPack/WiX/cmCPackWIXGenerator.cxx
@@ -64,7 +64,8 @@ bool cmCPackWIXGenerator::RunWiXCommand(std::string const& command)
   std::string output;
 
   int returnValue = 0;
-  bool status = cmSystemTools::RunSingleCommand(command.c_str(), &output,
+  bool status = cmSystemTools::RunSingleCommand(
+    command.c_str(), &output, &output,
     &returnValue, 0, cmSystemTools::OUTPUT_NONE);
 
   cmsys::ofstream logFile(logFileName.c_str(), std::ios::app);
diff --git a/Source/CPack/cmCPackDebGenerator.cxx b/Source/CPack/cmCPackDebGenerator.cxx
index fcf4122..fa02a3b 100644
--- a/Source/CPack/cmCPackDebGenerator.cxx
+++ b/Source/CPack/cmCPackDebGenerator.cxx
@@ -466,7 +466,7 @@ int cmCPackDebGenerator::createDeb()
 
   std::string output;
     int retval = -1;
-  int res = cmSystemTools::RunSingleCommand(cmd.c_str(), &output,
+  int res = cmSystemTools::RunSingleCommand(cmd.c_str(), &output, &output,
       &retval, this->GetOption("WDIR"), this->GeneratorVerbose, 0);
 
     if ( !res || retval )
@@ -505,7 +505,7 @@ int cmCPackDebGenerator::createDeb()
       cmd += "\"";
       //std::string output;
       //int retVal = -1;
-      res = cmSystemTools::RunSingleCommand(cmd.c_str(), &output,
+      res = cmSystemTools::RunSingleCommand(cmd.c_str(), &output, &output,
           &retval, toplevel.c_str(), this->GeneratorVerbose, 0);
       if ( !res || retval )
         {
@@ -553,7 +553,7 @@ int cmCPackDebGenerator::createDeb()
         }
       }
     }
-  res = cmSystemTools::RunSingleCommand(cmd.c_str(), &output,
+  res = cmSystemTools::RunSingleCommand(cmd.c_str(), &output, &output,
       &retval, this->GetOption("WDIR"), this->GeneratorVerbose, 0);
 
     if ( !res || retval )
diff --git a/Source/CPack/cmCPackDragNDropGenerator.cxx b/Source/CPack/cmCPackDragNDropGenerator.cxx
index 5da9234..4c400d9 100644
--- a/Source/CPack/cmCPackDragNDropGenerator.cxx
+++ b/Source/CPack/cmCPackDragNDropGenerator.cxx
@@ -197,7 +197,7 @@ bool cmCPackDragNDropGenerator::RunCommand(std::ostringstream& command,
 
   bool result = cmSystemTools::RunSingleCommand(
     command.str().c_str(),
-    output,
+    output, output,
     &exit_code,
     0,
     this->GeneratorVerbose,
diff --git a/Source/CPack/cmCPackGenerator.cxx b/Source/CPack/cmCPackGenerator.cxx
index 2b18c41..e254e9a 100644
--- a/Source/CPack/cmCPackGenerator.cxx
+++ b/Source/CPack/cmCPackGenerator.cxx
@@ -290,7 +290,8 @@ int cmCPackGenerator::InstallProjectViaInstallCommands(
         << std::endl);
       std::string output;
       int retVal = 1;
-      bool resB = cmSystemTools::RunSingleCommand(it->c_str(), &output,
+      bool resB = cmSystemTools::RunSingleCommand(
+        it->c_str(), &output, &output,
         &retVal, 0, this->GeneratorVerbose, 0);
       if ( !resB || retVal )
         {
@@ -668,7 +669,7 @@ int cmCPackGenerator::InstallProjectViaInstallCMakeProjects(
         int retVal = 1;
         bool resB =
           cmSystemTools::RunSingleCommand(buildCommand.c_str(),
-                                          &output,
+                                          &output, &output,
                                           &retVal,
                                           installDirectory.c_str(),
                                           this->GeneratorVerbose, 0);
diff --git a/Source/CPack/cmCPackNSISGenerator.cxx b/Source/CPack/cmCPackNSISGenerator.cxx
index fe6cc95..2de2bc4 100644
--- a/Source/CPack/cmCPackNSISGenerator.cxx
+++ b/Source/CPack/cmCPackNSISGenerator.cxx
@@ -324,7 +324,7 @@ int cmCPackNSISGenerator::PackageFiles()
     << std::endl);
   std::string output;
   int retVal = 1;
-  bool res = cmSystemTools::RunSingleCommand(nsisCmd.c_str(), &output,
+  bool res = cmSystemTools::RunSingleCommand(nsisCmd.c_str(), &output, &output,
     &retVal, 0, this->GeneratorVerbose, 0);
   if ( !res || retVal )
     {
@@ -430,8 +430,8 @@ int cmCPackNSISGenerator::InitializeInternal()
     << nsisCmd << std::endl);
   std::string output;
   int retVal = 1;
-  bool resS = cmSystemTools::RunSingleCommand(nsisCmd.c_str(),
-    &output, &retVal, 0, this->GeneratorVerbose, 0);
+  bool resS = cmSystemTools::RunSingleCommand(
+    nsisCmd.c_str(), &output, &output, &retVal, 0, this->GeneratorVerbose, 0);
   cmsys::RegularExpression versionRex("v([0-9]+.[0-9]+)");
   cmsys::RegularExpression versionRexCVS("v(.*)\\.cvs");
   if ( !resS || retVal ||
@@ -836,9 +836,9 @@ CreateComponentDescription(cmCPackComponent *component,
                                       zipListFileName.c_str());
     std::string output;
     int retVal = -1;
-    int res = cmSystemTools::RunSingleCommand(cmd.c_str(), &output, &retVal,
-                                              dirName.c_str(),
-                                              cmSystemTools::OUTPUT_NONE, 0);
+    int res = cmSystemTools::RunSingleCommand(
+      cmd.c_str(), &output, &output,
+      &retVal, dirName.c_str(), cmSystemTools::OUTPUT_NONE, 0);
     if ( !res || retVal )
     {
       std::string tmpFile = this->GetOption("CPACK_TOPLEVEL_DIRECTORY");
diff --git a/Source/CPack/cmCPackOSXX11Generator.cxx b/Source/CPack/cmCPackOSXX11Generator.cxx
index 313e08b..d533af8 100644
--- a/Source/CPack/cmCPackOSXX11Generator.cxx
+++ b/Source/CPack/cmCPackOSXX11Generator.cxx
@@ -180,9 +180,9 @@ int cmCPackOSXX11Generator::PackageFiles()
   bool res = false;
   while(numTries > 0)
     {
-    res = cmSystemTools::RunSingleCommand(dmgCmd.str().c_str(), &output,
-                                          &retVal, 0,
-                                          this->GeneratorVerbose, 0);
+    res = cmSystemTools::RunSingleCommand(
+      dmgCmd.str().c_str(), &output, &output,
+      &retVal, 0, this->GeneratorVerbose, 0);
     if ( res && !retVal )
       {
       numTries = -1;
diff --git a/Source/CPack/cmCPackPackageMakerGenerator.cxx b/Source/CPack/cmCPackPackageMakerGenerator.cxx
index dfe35c9..880663f 100644
--- a/Source/CPack/cmCPackPackageMakerGenerator.cxx
+++ b/Source/CPack/cmCPackPackageMakerGenerator.cxx
@@ -378,9 +378,9 @@ int cmCPackPackageMakerGenerator::PackageFiles()
   bool res = false;
   while(numTries > 0)
     {
-    res = cmSystemTools::RunSingleCommand(dmgCmd.str().c_str(), &output,
-                                          &retVal, 0, this->GeneratorVerbose,
-                                          0);
+    res = cmSystemTools::RunSingleCommand(
+      dmgCmd.str().c_str(), &output, &output,
+      &retVal, 0, this->GeneratorVerbose, 0);
     if ( res && !retVal )
       {
       numTries = -1;
@@ -657,8 +657,9 @@ bool cmCPackPackageMakerGenerator::RunPackageMaker(const char *command,
   cmCPackLogger(cmCPackLog::LOG_VERBOSE, "Execute: " << command << std::endl);
   std::string output;
   int retVal = 1;
-  bool res = cmSystemTools::RunSingleCommand(command, &output, &retVal, 0,
-                                             this->GeneratorVerbose, 0);
+  bool res = cmSystemTools::RunSingleCommand(
+    command, &output, &output,
+    &retVal, 0, this->GeneratorVerbose, 0);
   cmCPackLogger(cmCPackLog::LOG_VERBOSE, "Done running package maker"
     << std::endl);
   if ( !res || retVal )
diff --git a/Source/CTest/cmCTestScriptHandler.cxx b/Source/CTest/cmCTestScriptHandler.cxx
index 7f9825c..d1e7e3a 100644
--- a/Source/CTest/cmCTestScriptHandler.cxx
+++ b/Source/CTest/cmCTestScriptHandler.cxx
@@ -709,7 +709,8 @@ int cmCTestScriptHandler::CheckOutSourceDir()
     output = "";
     cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT,
       "Run cvs: " << this->CVSCheckOut << std::endl);
-    res = cmSystemTools::RunSingleCommand(this->CVSCheckOut.c_str(), &output,
+    res = cmSystemTools::RunSingleCommand(
+      this->CVSCheckOut.c_str(), &output, &output,
       &retVal, this->CTestRoot.c_str(), this->HandlerVerbose,
       0 /*this->TimeOut*/);
     if (!res || retVal != 0)
@@ -789,7 +790,8 @@ int cmCTestScriptHandler::PerformExtraUpdates()
       retVal = 0;
       cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT, "Run Update: "
         << fullCommand << std::endl);
-      res = cmSystemTools::RunSingleCommand(fullCommand.c_str(), &output,
+      res = cmSystemTools::RunSingleCommand(
+        fullCommand.c_str(), &output, &output,
         &retVal, cvsArgs[0].c_str(),
         this->HandlerVerbose, 0 /*this->TimeOut*/);
       if (!res || retVal != 0)
@@ -910,7 +912,8 @@ int cmCTestScriptHandler::RunConfigurationDashboard()
     retVal = 0;
     cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT, "Run cmake command: "
       << command << std::endl);
-    res = cmSystemTools::RunSingleCommand(command.c_str(), &output,
+    res = cmSystemTools::RunSingleCommand(
+      command.c_str(), &output, &output,
       &retVal, this->BinaryDir.c_str(),
       this->HandlerVerbose, 0 /*this->TimeOut*/);
 
@@ -956,7 +959,8 @@ int cmCTestScriptHandler::RunConfigurationDashboard()
     retVal = 0;
     cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT, "Run ctest command: "
       << command << std::endl);
-    res = cmSystemTools::RunSingleCommand(command.c_str(), &output,
+    res = cmSystemTools::RunSingleCommand(
+      command.c_str(), &output, &output,
       &retVal, this->BinaryDir.c_str(), this->HandlerVerbose,
       0 /*this->TimeOut*/);
 
diff --git a/Source/CTest/cmCTestTestHandler.cxx b/Source/CTest/cmCTestTestHandler.cxx
index d778253..95cdf3b 100644
--- a/Source/CTest/cmCTestTestHandler.cxx
+++ b/Source/CTest/cmCTestTestHandler.cxx
@@ -1334,7 +1334,7 @@ int cmCTestTestHandler::ExecuteCommands(std::vector<std::string>& vec)
     int retVal = 0;
     cmCTestOptionalLog(this->CTest, HANDLER_VERBOSE_OUTPUT, "Run command: " <<
       *it << std::endl, this->Quiet);
-    if ( !cmSystemTools::RunSingleCommand(it->c_str(), 0, &retVal, 0,
+    if ( !cmSystemTools::RunSingleCommand(it->c_str(), 0, 0, &retVal, 0,
                                           cmSystemTools::OUTPUT_MERGE
         /*this->Verbose*/) || retVal != 0 )
       {
diff --git a/Source/cmBuildNameCommand.cxx b/Source/cmBuildNameCommand.cxx
index 2a06574..2733d76 100644
--- a/Source/cmBuildNameCommand.cxx
+++ b/Source/cmBuildNameCommand.cxx
@@ -49,7 +49,7 @@ bool cmBuildNameCommand
   if(this->Makefile->GetDefinition("UNIX"))
     {
     buildname = "";
-    cmSystemTools::RunSingleCommand("uname -a", &buildname);
+    cmSystemTools::RunSingleCommand("uname -a", &buildname, &buildname);
     if(!buildname.empty())
       {
       std::string RegExp = "([^ ]*) [^ ]* ([^ ]*) ";
diff --git a/Source/cmExtraEclipseCDT4Generator.cxx b/Source/cmExtraEclipseCDT4Generator.cxx
index 2aa4d93..24043af 100644
--- a/Source/cmExtraEclipseCDT4Generator.cxx
+++ b/Source/cmExtraEclipseCDT4Generator.cxx
@@ -1163,7 +1163,7 @@ cmExtraEclipseCDT4Generator::GetEclipsePath(const std::string& path)
 #if defined(__CYGWIN__)
   std::string cmd = "cygpath -m " + path;
   std::string out;
-  if (!cmSystemTools::RunSingleCommand(cmd.c_str(), &out))
+  if (!cmSystemTools::RunSingleCommand(cmd.c_str(), &out, &out))
     {
     return path;
     }
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index 4a9f628..4b0ef58 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -1737,7 +1737,7 @@ int cmGlobalGenerator::Build(
     output += cmSystemTools::PrintSingleCommand(cleanCommand);
     output += "\n";
 
-    if (!cmSystemTools::RunSingleCommand(cleanCommand, outputPtr,
+    if (!cmSystemTools::RunSingleCommand(cleanCommand, outputPtr, outputPtr,
                                          &retVal, 0, outputflag, timeout))
       {
       cmSystemTools::SetRunCommandHideConsole(hideconsole);
@@ -1758,7 +1758,7 @@ int cmGlobalGenerator::Build(
   output += makeCommandStr;
   output += "\n";
 
-  if (!cmSystemTools::RunSingleCommand(makeCommand, outputPtr,
+  if (!cmSystemTools::RunSingleCommand(makeCommand, outputPtr, outputPtr,
                                        &retVal, 0, outputflag, timeout))
     {
     cmSystemTools::SetRunCommandHideConsole(hideconsole);
diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index 505914e..79a7914 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -1233,7 +1233,7 @@ std::string cmGlobalNinjaGenerator::ninjaVersion() const
   std::string version;
   std::string command = ninjaCmd() + " --version";
   cmSystemTools::RunSingleCommand(command.c_str(),
-                                  &version, 0, 0,
+                                  &version, 0, 0, 0,
                                   cmSystemTools::OUTPUT_NONE);
 
   return version;
diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index 8c37338..04befee 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -164,8 +164,8 @@ cmGlobalGenerator* cmGlobalXCodeGenerator::Factory
   {
   std::string out;
   std::string::size_type pos;
-  if(cmSystemTools::RunSingleCommand("xcode-select --print-path", &out, 0, 0,
-                                     cmSystemTools::OUTPUT_NONE) &&
+  if(cmSystemTools::RunSingleCommand("xcode-select --print-path", &out, 0,
+                                     0, 0, cmSystemTools::OUTPUT_NONE) &&
      (pos = out.find(".app/"), pos != out.npos))
     {
     versionFile = out.substr(0, pos+5)+"Contents/version.plist";
diff --git a/Source/cmQtAutoGenerators.cxx b/Source/cmQtAutoGenerators.cxx
index 3d5103f..329f9de 100644
--- a/Source/cmQtAutoGenerators.cxx
+++ b/Source/cmQtAutoGenerators.cxx
@@ -188,7 +188,7 @@ std::string cmQtAutoGenerators::ListQt5RccInputs(cmSourceFile* sf,
 
   std::string output;
   int retVal = 0;
-  bool result = cmSystemTools::RunSingleCommand(command, &output,
+  bool result = cmSystemTools::RunSingleCommand(command, &output, &output,
                                             &retVal, 0,
                                             cmSystemTools::OUTPUT_NONE);
   if (!result || retVal)
@@ -2196,7 +2196,8 @@ bool cmQtAutoGenerators::GenerateMoc(const std::string& sourceFile,
 
     std::string output;
     int retVal = 0;
-    bool result = cmSystemTools::RunSingleCommand(command, &output, &retVal);
+    bool result = cmSystemTools::RunSingleCommand(command, &output, &output,
+                                                  &retVal);
     if (!result || retVal)
       {
       std::cerr << "AUTOGEN: error: process for " << mocFilePath <<" failed:\n"
@@ -2265,7 +2266,8 @@ bool cmQtAutoGenerators::GenerateUi(const std::string& realName,
       }
     std::string output;
     int retVal = 0;
-    bool result = cmSystemTools::RunSingleCommand(command, &output, &retVal);
+    bool result = cmSystemTools::RunSingleCommand(command, &output, &output,
+                                                  &retVal);
     if (!result || retVal)
       {
       std::cerr << "AUTOUIC: error: process for " << ui_output_file <<
@@ -2355,7 +2357,8 @@ bool cmQtAutoGenerators::GenerateQrc()
         }
       std::string output;
       int retVal = 0;
-      bool result = cmSystemTools::RunSingleCommand(command, &output, &retVal);
+      bool result = cmSystemTools::RunSingleCommand(command, &output, &output,
+                                                    &retVal);
       if (!result || retVal)
         {
         std::cerr << "AUTORCC: error: process for " << rcc_output_file <<
diff --git a/Source/cmSiteNameCommand.cxx b/Source/cmSiteNameCommand.cxx
index 20a61a0..e2970e5 100644
--- a/Source/cmSiteNameCommand.cxx
+++ b/Source/cmSiteNameCommand.cxx
@@ -63,7 +63,7 @@ bool cmSiteNameCommand
     {
     std::string host;
     cmSystemTools::RunSingleCommand(hostname_cmd.c_str(),
-      &host, 0, 0, cmSystemTools::OUTPUT_NONE);
+      &host, 0, 0, 0, cmSystemTools::OUTPUT_NONE);
 
     // got the hostname
     if (!host.empty())
diff --git a/Source/cmSystemTools.cxx b/Source/cmSystemTools.cxx
index 95d05a6..0e0532d 100644
--- a/Source/cmSystemTools.cxx
+++ b/Source/cmSystemTools.cxx
@@ -659,7 +659,8 @@ std::vector<std::string> cmSystemTools::ParseArguments(const char* command)
 
 
 bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
-                                     std::string* output ,
+                                     std::string* captureStdOut,
+                                     std::string* captureStdErr,
                                      int* retVal , const char* dir ,
                                      OutputOption outputflag ,
                                      double timeout )
@@ -671,9 +672,13 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
     argv.push_back(a->c_str());
     }
   argv.push_back(0);
-  if ( output )
+  if ( captureStdOut )
     {
-    *output = "";
+    *captureStdOut = "";
+    }
+  if (captureStdErr && captureStdErr != captureStdOut)
+    {
+    *captureStdErr = "";
     }
 
   cmsysProcess* cp = cmsysProcess_New();
@@ -693,15 +698,17 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
   cmsysProcess_SetTimeout(cp, timeout);
   cmsysProcess_Execute(cp);
 
-  std::vector<char> tempOutput;
+  std::vector<char> tempStdOut;
+  std::vector<char> tempStdErr;
   char* data;
   int length;
   int pipe;
-  if(outputflag != OUTPUT_PASSTHROUGH && (output || outputflag != OUTPUT_NONE))
+  if(outputflag != OUTPUT_PASSTHROUGH &&
+     (captureStdOut || captureStdErr || outputflag != OUTPUT_NONE))
     {
     while((pipe = cmsysProcess_WaitForData(cp, &data, &length, 0)) > 0)
       {
-      if(output || outputflag != OUTPUT_NONE)
+      if(captureStdOut || captureStdErr || outputflag != OUTPUT_NONE)
         {
         // Translate NULL characters in the output into valid text.
         // Visual Studio 7 puts these characters in the output of its
@@ -714,9 +721,21 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
             }
           }
         }
-      if ( output )
+      if(pipe == cmsysProcess_Pipe_STDOUT ||
+         (pipe == cmsysProcess_Pipe_STDERR &&
+          captureStdOut == captureStdErr))
+        {
+        if (captureStdOut)
+          {
+          tempStdOut.insert(tempStdOut.end(), data, data+length);
+          }
+        }
+      else if(pipe == cmsysProcess_Pipe_STDERR)
         {
-        tempOutput.insert(tempOutput.end(), data, data+length);
+        if (captureStdErr)
+          {
+          tempStdErr.insert(tempStdErr.end(), data, data+length);
+          }
         }
       if(outputflag != OUTPUT_NONE)
         {
@@ -740,9 +759,14 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
     }
 
   cmsysProcess_WaitForExit(cp, 0);
-  if ( output && tempOutput.begin() != tempOutput.end())
+  if ( captureStdOut && tempStdOut.begin() != tempStdOut.end())
+    {
+    captureStdOut->append(&*tempStdOut.begin(), tempStdOut.size());
+    }
+  if ( captureStdErr && captureStdErr != captureStdOut &&
+       tempStdErr.begin() != tempStdErr.end())
     {
-    output->append(&*tempOutput.begin(), tempOutput.size());
+    captureStdErr->append(&*tempStdErr.begin(), tempStdErr.size());
     }
 
   bool result = true;
@@ -767,9 +791,9 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
       {
       std::cerr << exception_str << std::endl;
       }
-    if ( output )
+    if ( captureStdErr )
       {
-      output->append(exception_str, strlen(exception_str));
+      captureStdErr->append(exception_str, strlen(exception_str));
       }
     result = false;
     }
@@ -780,9 +804,9 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
       {
       std::cerr << error_str << std::endl;
       }
-    if ( output )
+    if ( captureStdErr )
       {
-      output->append(error_str, strlen(error_str));
+      captureStdErr->append(error_str, strlen(error_str));
       }
     result = false;
     }
@@ -793,9 +817,9 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
       {
       std::cerr << error_str << std::endl;
       }
-    if ( output )
+    if ( captureStdErr )
       {
-      output->append(error_str, strlen(error_str));
+      captureStdErr->append(error_str, strlen(error_str));
       }
     result = false;
     }
@@ -806,7 +830,8 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
 
 bool cmSystemTools::RunSingleCommand(
   const char* command,
-  std::string* output,
+  std::string* captureStdOut,
+  std::string* captureStdErr,
   int *retVal,
   const char* dir,
   OutputOption outputflag,
@@ -823,8 +848,8 @@ bool cmSystemTools::RunSingleCommand(
     {
     return false;
     }
-  return cmSystemTools::RunSingleCommand(args, output,retVal,
-                                         dir, outputflag, timeout);
+  return cmSystemTools::RunSingleCommand(args, captureStdOut, captureStdErr,
+                                         retVal, dir, outputflag, timeout);
 }
 
 std::string
diff --git a/Source/cmSystemTools.h b/Source/cmSystemTools.h
index 433ef46..6feb6c5 100644
--- a/Source/cmSystemTools.h
+++ b/Source/cmSystemTools.h
@@ -223,7 +223,9 @@ public:
      OUTPUT_NORMAL,
      OUTPUT_PASSTHROUGH
    };
-  static bool RunSingleCommand(const char* command, std::string* output = 0,
+  static bool RunSingleCommand(const char* command,
+                               std::string* captureStdOut = 0,
+                               std::string* captureStdErr = 0,
                                int* retVal = 0, const char* dir = 0,
                                OutputOption outputflag = OUTPUT_MERGE,
                                double timeout = 0.0);
@@ -233,7 +235,8 @@ public:
    * be in comand[1]...command[command.size()]
    */
   static bool RunSingleCommand(std::vector<std::string> const& command,
-                               std::string* output = 0,
+                               std::string* captureStdOut = 0,
+                               std::string* captureStdErr = 0,
                                int* retVal = 0, const char* dir = 0,
                                OutputOption outputflag = OUTPUT_MERGE,
                                double timeout = 0.0);
diff --git a/Source/cmTryRunCommand.cxx b/Source/cmTryRunCommand.cxx
index c9e7a46..3cd92cb 100644
--- a/Source/cmTryRunCommand.cxx
+++ b/Source/cmTryRunCommand.cxx
@@ -224,7 +224,7 @@ void cmTryRunCommand::RunExecutable(const std::string& runArgs,
     }
   int timeout = 0;
   bool worked = cmSystemTools::RunSingleCommand(finalCommand.c_str(),
-                out, &retVal,
+                out, out, &retVal,
                 0, cmSystemTools::OUTPUT_NONE, timeout);
   // set the run var
   char retChar[1000];
diff --git a/Source/cmcldeps.cxx b/Source/cmcldeps.cxx
index 55fc633..f3c6059 100644
--- a/Source/cmcldeps.cxx
+++ b/Source/cmcldeps.cxx
@@ -206,8 +206,9 @@ static int process( const std::string& srcfilename,
     }
   // run the command
   int exit_code = 0;
-  bool run = cmSystemTools::RunSingleCommand(command, &output, &exit_code,
-                                    dir.c_str(), cmSystemTools::OUTPUT_NONE);
+  bool run = cmSystemTools::RunSingleCommand(command, &output, &output,
+                                             &exit_code, dir.c_str(),
+                                             cmSystemTools::OUTPUT_NONE);
 
   // process the include directives and output everything else
   std::stringstream ss(output);
diff --git a/Source/cmcmd.cxx b/Source/cmcmd.cxx
index 2ef04ef..5e56957 100644
--- a/Source/cmcmd.cxx
+++ b/Source/cmcmd.cxx
@@ -267,7 +267,7 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string>& args)
       std::vector<std::string> cmd(ai, ae);
       int retval;
       if(cmSystemTools::RunSingleCommand(
-           cmd, 0, &retval, NULL, cmSystemTools::OUTPUT_PASSTHROUGH))
+           cmd, 0, 0, &retval, NULL, cmSystemTools::OUTPUT_PASSTHROUGH))
         {
         return retval;
         }
@@ -398,7 +398,7 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string>& args)
       time(&time_start);
       clock_start = clock();
       int ret =0;
-      cmSystemTools::RunSingleCommand(command.c_str(), 0, &ret);
+      cmSystemTools::RunSingleCommand(command.c_str(), 0, 0, &ret);
 
       clock_finish = clock();
       time(&time_finish);
@@ -454,7 +454,7 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string>& args)
       std::string command = cmWrap('"', cmRange(args).advance(3), '"', " ");
       int retval = 0;
       int timeout = 0;
-      if ( cmSystemTools::RunSingleCommand(command.c_str(), 0, &retval,
+      if ( cmSystemTools::RunSingleCommand(command.c_str(), 0, 0, &retval,
              directory.c_str(), cmSystemTools::OUTPUT_NORMAL, timeout) )
         {
         return retval;
@@ -1350,7 +1350,7 @@ bool cmcmd::RunCommand(const char* comment,
   int retCode =0;
   // use rc command to create .res file
   cmSystemTools::RunSingleCommand(command,
-                                  &output,
+                                  &output, &output,
                                   &retCode, 0, cmSystemTools::OUTPUT_NONE);
   // always print the output of the command, unless
   // it is the dumb rc command banner, but if the command
diff --git a/Tests/CMakeLib/run_compile_commands.cxx b/Tests/CMakeLib/run_compile_commands.cxx
index 279bcd5..26ab223 100644
--- a/Tests/CMakeLib/run_compile_commands.cxx
+++ b/Tests/CMakeLib/run_compile_commands.cxx
@@ -130,7 +130,7 @@ int main ()
     std::vector<std::string> command;
     cmSystemTools::ParseUnixCommandLine(it->at("command").c_str(), command);
     if (!cmSystemTools::RunSingleCommand(
-            command, 0, 0, it->at("directory").c_str()))
+            command, 0, 0, 0, it->at("directory").c_str()))
       {
       std::cout << "ERROR: Failed to run command \""
                 << command[0] << "\"" << std::endl;