ENH: Handle large object file lists on some platforms

  - Use a response file when enabled by
    CMAKE_<LANG>_USE_RESPONSE_FILE_FOR_OBJECTS
  - Enable for C and CXX with cl (MSVC)
  - Enable for Fortran with ifort (Intel Fortran)

5 files changed, 84 insertions, 2 deletions

diff --git a/Source/cmDocumentVariables.cxx b/Source/cmDocumentVariables.cxx
index 4466a0f..0a54849 100644
--- a/Source/cmDocumentVariables.cxx
+++ b/Source/cmDocumentVariables.cxx
@@ -1059,6 +1059,8 @@ void cmDocumentVariables::DefineVariables(cmake* cm)
                      cmProperty::VARIABLE,0,0);
   cm->DefineProperty("CMAKE_<LANG>_STANDARD_LIBRARIES_INIT",
                      cmProperty::VARIABLE,0,0);
+  cm->DefineProperty("CMAKE_<LANG>_USE_RESPONSE_FILE_FOR_OBJECTS",
+                     cmProperty::VARIABLE,0,0);
   cm->DefineProperty("CMAKE_EXECUTABLE_SUFFIX_<LANG>",
                      cmProperty::VARIABLE,0,0);
   cm->DefineProperty("CMAKE_EXE_LINK_DYNAMIC_<LANG>_FLAGS",
diff --git a/Source/cmMakefileExecutableTargetGenerator.cxx b/Source/cmMakefileExecutableTargetGenerator.cxx
index 9e8d42d..1715fe9 100644
--- a/Source/cmMakefileExecutableTargetGenerator.cxx
+++ b/Source/cmMakefileExecutableTargetGenerator.cxx
@@ -328,6 +328,18 @@ void cmMakefileExecutableTargetGenerator::WriteExecutableRule(bool relink)
       }
     }
 
+  // Select whether to use a response file for objects.
+  bool useResponseFile = false;
+  {
+  std::string responseVar = "CMAKE_";
+  responseVar += linkLanguage;
+  responseVar += "_USE_RESPONSE_FILE_FOR_OBJECTS";
+  if(this->Makefile->IsOn(responseVar.c_str()))
+    {
+    useResponseFile = true;
+    }
+  }
+
   // Expand the rule variables.
   {
   // Set path conversion for link script shells.
@@ -343,7 +355,18 @@ void cmMakefileExecutableTargetGenerator::WriteExecutableRule(bool relink)
   std::string variableNameExternal;
   this->WriteObjectsVariable(variableName, variableNameExternal);
   std::string buildObjs;
-  if(useLinkScript)
+  if(useResponseFile)
+    {
+    std::string objects;
+    this->WriteObjectsString(objects);
+    std::string objects_rsp =
+      this->CreateResponseFile("objects.rsp", objects, depends);
+    buildObjs = "@";
+    buildObjs += this->Convert(objects_rsp.c_str(),
+                               cmLocalGenerator::NONE,
+                               cmLocalGenerator::SHELL);
+    }
+  else if(useLinkScript)
     {
     this->WriteObjectsString(buildObjs);
     }
diff --git a/Source/cmMakefileLibraryTargetGenerator.cxx b/Source/cmMakefileLibraryTargetGenerator.cxx
index dd4c9eb..1c7f108 100644
--- a/Source/cmMakefileLibraryTargetGenerator.cxx
+++ b/Source/cmMakefileLibraryTargetGenerator.cxx
@@ -567,6 +567,18 @@ void cmMakefileLibraryTargetGenerator::WriteLibraryRules
   // Determine whether a link script will be used.
   bool useLinkScript = this->GlobalGenerator->GetUseLinkScript();
 
+  // Select whether to use a response file for objects.
+  bool useResponseFile = false;
+  {
+  std::string responseVar = "CMAKE_";
+  responseVar += linkLanguage;
+  responseVar += "_USE_RESPONSE_FILE_FOR_OBJECTS";
+  if(this->Makefile->IsOn(responseVar.c_str()))
+    {
+    useResponseFile = true;
+    }
+  }
+
   // For static libraries there might be archiving rules.
   std::vector<std::string> archiveCreateCommands;
   std::vector<std::string> archiveAppendCommands;
@@ -605,6 +617,9 @@ void cmMakefileLibraryTargetGenerator::WriteLibraryRules
     // Archiving rules are always run with a link script.
     useLinkScript = true;
 
+    // Archiving rules never use a response file.
+    useResponseFile = false;
+
     // Limit the length of individual object lists to less than the
     // 32K command line length limit on Windows.  We could make this a
     // platform file variable but this should work everywhere.
@@ -631,7 +646,18 @@ void cmMakefileLibraryTargetGenerator::WriteLibraryRules
   std::string variableNameExternal;
   this->WriteObjectsVariable(variableName, variableNameExternal);
   std::string buildObjs;
-  if(useLinkScript)
+  if(useResponseFile)
+    {
+    std::string objects;
+    this->WriteObjectsString(objects);
+    std::string objects_rsp =
+      this->CreateResponseFile("objects.rsp", objects, depends);
+    buildObjs = "@";
+    buildObjs += this->Convert(objects_rsp.c_str(),
+                               cmLocalGenerator::NONE,
+                               cmLocalGenerator::SHELL);
+    }
+  else if(useLinkScript)
     {
     if(!useArchiveRules)
       {
diff --git a/Source/cmMakefileTargetGenerator.cxx b/Source/cmMakefileTargetGenerator.cxx
index f268ddf..b15410b 100644
--- a/Source/cmMakefileTargetGenerator.cxx
+++ b/Source/cmMakefileTargetGenerator.cxx
@@ -1584,6 +1584,30 @@ cmMakefileTargetGenerator
 }
 
 //----------------------------------------------------------------------------
+std::string
+cmMakefileTargetGenerator
+::CreateResponseFile(const char* name, std::string const& options,
+                     std::vector<std::string>& makefile_depends)
+{
+  // Create the response file.
+  std::string responseFileNameFull = this->TargetBuildDirectoryFull;
+  responseFileNameFull += "/";
+  responseFileNameFull += name;
+  cmGeneratedFileStream responseStream(responseFileNameFull.c_str());
+  responseStream << options << "\n";
+
+  // Add a dependency so the target will rebuild when the set of
+  // objects changes.
+  makefile_depends.push_back(responseFileNameFull);
+
+  // Construct the name to be used on the command line.
+  std::string responseFileName = this->TargetBuildDirectory;
+  responseFileName += "/";
+  responseFileName += name;
+  return responseFileName;
+}
+
+//----------------------------------------------------------------------------
 const char* cmMakefileTargetGenerator::GetFortranModuleDirectory()
 {
   // Compute the module directory.
diff --git a/Source/cmMakefileTargetGenerator.h b/Source/cmMakefileTargetGenerator.h
index 1039f3d..3a6ec0d 100644
--- a/Source/cmMakefileTargetGenerator.h
+++ b/Source/cmMakefileTargetGenerator.h
@@ -137,6 +137,13 @@ protected:
                         std::vector<std::string>& makefile_commands,
                         std::vector<std::string>& makefile_depends);
 
+  /** Create a response file with the given set of options.  Returns
+      the relative path from the target build working directory to the
+      response file name.  */
+  std::string CreateResponseFile(const char* name,
+                                 std::string const& options,
+                                 std::vector<std::string>& makefile_depends);
+
   virtual void CloseFileStreams();
   void RemoveForbiddenFlags(const char* flagVar, const char* linkLang,
                             std::string& linkFlags);