Merge topic 'cleanup-RunSingleCommand'

1040e690 cmSystemTools: Teach RunSingleCommand to merge child pipes when possible
ce3b713b cmSystemTools: Simplify RunSingleCommand output string construction
dc039cc0 cmSystemTools: Drop redundant condition in RunSingleCommand
ffa2a8c9 cmSystemTools: Rename OUTPUT_NORMAL to OUTPUT_FORWARD to clarify its purpose
92e9bb21 cmcmd.cxx: Remove unused code in __run_iwyu implementation
fb1526f5 cmake: Change `-E chdir` to pass through stdout/stderr directly

Source/cmGlobalGenerator.cxx

@@ -1850,7 +1850,7 @@ int cmGlobalGenerator::Build(
       !makeCommand.empty() && cmSystemTools::LowerCase(
         cmSystemTools::GetFilenameName(makeCommand[0])) == "vcexpress.exe")
     {
-    outputflag = cmSystemTools::OUTPUT_NORMAL;
+    outputflag = cmSystemTools::OUTPUT_FORWARD;
     }
 
   // should we do a clean first?

Source/cmSystemTools.cxx

@@ -17,6 +17,7 @@
 #include <time.h>
 #include <string.h>
 #include <stdlib.h>
+#include <assert.h>
 #ifdef __QNX__
 # include <malloc.h> /* for malloc/free on QNX */
 #endif
@@ -660,14 +661,6 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
     argv.push_back(a->c_str());
     }
   argv.push_back(0);
-  if ( captureStdOut )
-    {
-    *captureStdOut = "";
-    }
-  if (captureStdErr && captureStdErr != captureStdOut)
-    {
-    *captureStdErr = "";
-    }
 
   cmsysProcess* cp = cmsysProcess_New();
   cmsysProcess_SetCommand(cp, &*argv.begin());
@@ -681,7 +674,16 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
     {
     cmsysProcess_SetPipeShared(cp, cmsysProcess_Pipe_STDOUT, 1);
     cmsysProcess_SetPipeShared(cp, cmsysProcess_Pipe_STDERR, 1);
+    captureStdOut = 0;
+    captureStdErr = 0;
     }
+  else if (outputflag == OUTPUT_MERGE ||
+           (captureStdErr && captureStdErr == captureStdOut))
+    {
+    cmsysProcess_SetOption(cp, cmsysProcess_Option_MergeOutput, 1);
+    captureStdErr = 0;
+    }
+  assert(!captureStdErr || captureStdErr != captureStdOut);
 
   cmsysProcess_SetTimeout(cp, timeout);
   cmsysProcess_Execute(cp);
@@ -696,65 +698,50 @@ bool cmSystemTools::RunSingleCommand(std::vector<std::string>const& command,
     {
     while((pipe = cmsysProcess_WaitForData(cp, &data, &length, 0)) > 0)
       {
-      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
+      // build process.
+      for(int i=0; i < length; ++i)
         {
-        // Translate NULL characters in the output into valid text.
-        // Visual Studio 7 puts these characters in the output of its
-        // build process.
-        for(int i=0; i < length; ++i)
+        if(data[i] == '\0')
           {
-          if(data[i] == '\0')
-            {
-            data[i] = ' ';
-            }
+          data[i] = ' ';
           }
         }
-      if(pipe == cmsysProcess_Pipe_STDOUT ||
-         (pipe == cmsysProcess_Pipe_STDERR &&
-          captureStdOut == captureStdErr))
+
+      if (pipe == cmsysProcess_Pipe_STDOUT)
         {
-        if (captureStdOut)
+        if (outputflag != OUTPUT_NONE)
           {
-          tempStdOut.insert(tempStdOut.end(), data, data+length);
+          cmSystemTools::Stdout(data, length);
           }
-        }
-      else if(pipe == cmsysProcess_Pipe_STDERR)
-        {
-        if (captureStdErr)
+        if (captureStdOut)
           {
-          tempStdErr.insert(tempStdErr.end(), data, data+length);
+          tempStdOut.insert(tempStdOut.end(), data, data+length);
           }
         }
-      if(outputflag != OUTPUT_NONE)
+      else if (pipe == cmsysProcess_Pipe_STDERR)
         {
-        if(outputflag == OUTPUT_MERGE)
+        if (outputflag != OUTPUT_NONE)
           {
-          cmSystemTools::Stdout(data, length);
+          cmSystemTools::Stderr(data, length);
           }
-        else
+        if (captureStdErr)
           {
-          if(pipe == cmsysProcess_Pipe_STDERR)
-            {
-            cmSystemTools::Stderr(data, length);
-            }
-          else if(pipe == cmsysProcess_Pipe_STDOUT)
-            {
-            cmSystemTools::Stdout(data, length);
-            }
+          tempStdErr.insert(tempStdErr.end(), data, data+length);
           }
         }
       }
     }
 
   cmsysProcess_WaitForExit(cp, 0);
-  if ( captureStdOut && tempStdOut.begin() != tempStdOut.end())
+  if (captureStdOut)
     {
-    captureStdOut->append(&*tempStdOut.begin(), tempStdOut.size());
+    captureStdOut->assign(tempStdOut.begin(), tempStdOut.end());
     }
-  if ( captureStdErr && captureStdErr != captureStdOut &&
-       tempStdErr.begin() != tempStdErr.end())
+  if (captureStdErr)
     {
-    captureStdErr->append(&*tempStdErr.begin(), tempStdErr.size());
+    captureStdErr->assign(tempStdErr.begin(), tempStdErr.end());
     }
 
   bool result = true;

Source/cmSystemTools.h

@@ -203,7 +203,7 @@ public:
    * Output is controlled with outputflag. If outputflag is OUTPUT_NONE, no
    * user-viewable output from the program being run will be generated.
    * OUTPUT_MERGE is the legacy behaviour where stdout and stderr are merged
-   * into stdout.  OUTPUT_NORMAL passes through the output to stdout/stderr as
+   * into stdout.  OUTPUT_FORWARD copies the output to stdout/stderr as
    * it was received.  OUTPUT_PASSTHROUGH passes through the original handles.
    *
    * If timeout is specified, the command will be terminated after
@@ -223,7 +223,7 @@ public:
    {
      OUTPUT_NONE = 0,
      OUTPUT_MERGE,
-     OUTPUT_NORMAL,
+     OUTPUT_FORWARD,
      OUTPUT_PASSTHROUGH
    };
   static bool RunSingleCommand(const char* command,

Source/cmcmd.cxx

@@ -361,11 +361,10 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string>& args)
         }
 
       // Now run the real compiler command and return its result value.
-      if(!cmSystemTools::RunSingleCommand(orig_cmd, 0, &stdErr, &ret, 0,
+      if(!cmSystemTools::RunSingleCommand(orig_cmd, 0, 0, &ret, 0,
                                           cmSystemTools::OUTPUT_PASSTHROUGH))
         {
-        std::cerr << "Error running '" << orig_cmd[0] << "': "
-                  << stdErr << "\n";
+        std::cerr << "Error running '" << orig_cmd[0] << "'\n";
         return 1;
         }
       return ret;
@@ -621,7 +620,7 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string>& args)
       int retval = 0;
       int timeout = 0;
       if ( cmSystemTools::RunSingleCommand(command.c_str(), 0, 0, &retval,
-             directory.c_str(), cmSystemTools::OUTPUT_NORMAL, timeout) )
+             directory.c_str(), cmSystemTools::OUTPUT_PASSTHROUGH, timeout) )
         {
         return retval;
         }