Create a static library's output dir for VS 6

VS 6 forgets to create the output directory for a static library if it
differs from the intermediate files directory.  We work around this VS
bug by creating a pre-link event on the library target to make the
directory.

Source/cmLocalVisualStudio6Generator.cxx

@@ -825,6 +825,34 @@ void cmLocalVisualStudio6Generator::SetBuildType(BuildType b,
     }
 }
 
+//----------------------------------------------------------------------------
+cmsys::auto_ptr<cmCustomCommand>
+cmLocalVisualStudio6Generator::MaybeCreateOutputDir(cmTarget& target,
+                                                    const char* config)
+{
+  cmsys::auto_ptr<cmCustomCommand> pcc;
+
+  // VS6 forgets to create the output directory for archives if it
+  // differs from the intermediate directory.
+  if(target.GetType() != cmTarget::STATIC_LIBRARY) { return pcc; }
+  std::string outDir = target.GetDirectory(config, false);
+
+  // Add a pre-link event to create the directory.
+  cmCustomCommandLine command;
+  command.push_back(this->Makefile->GetRequiredDefinition("CMAKE_COMMAND"));
+  command.push_back("-E");
+  command.push_back("make_directory");
+  command.push_back(outDir);
+  std::vector<std::string> no_output;
+  std::vector<std::string> no_depends;
+  cmCustomCommandLines commands;
+  commands.push_back(command);
+  pcc.reset(new cmCustomCommand(no_output, no_depends, commands, 0, 0));
+  pcc->SetEscapeOldStyle(false);
+  pcc->SetEscapeAllowMakeVars(true);
+  return pcc;
+}
+
 // look for custom rules on a target and collect them together
 std::string 
 cmLocalVisualStudio6Generator::CreateTargetRules(cmTarget &target, 
@@ -845,6 +873,11 @@ cmLocalVisualStudio6Generator::CreateTargetRules(cmTarget &target,
   event.Write(target.GetPreLinkCommands());
   cmsys::auto_ptr<cmCustomCommand> pcc(
     this->MaybeCreateImplibDir(target, configName));
+  if(pcc.get())
+    {
+    event.Write(*pcc);
+    }
+  pcc = this->MaybeCreateOutputDir(target, configName);
   if(pcc.get())
     {
     event.Write(*pcc);

Source/cmLocalVisualStudio6Generator.h

@@ -81,6 +81,8 @@ private:
                   std::ostream &fout, const char *libName);
   class EventWriter;
   friend class EventWriter;
+  cmsys::auto_ptr<cmCustomCommand>
+  MaybeCreateOutputDir(cmTarget& target, const char* config);
   std::string CreateTargetRules(cmTarget &target, 
                                 const char* configName, 
                                 const char *libName);