ENH: New foreach(<var> IN ...) mode

This creates a new mode of the foreach command which allows precise
iteration even over empty elements.  This mode may be safely extended
with more keyword arguments in the future.  The cost now is possibly
breaking scripts that iterate over a list of items beginning with 'IN',
but there is no other way to extend the syntax in a readable way.

1 files changed, 48 insertions, 0 deletions

diff --git a/Source/cmForEachCommand.cxx b/Source/cmForEachCommand.cxx
index 7a826c6310..7a035237fb 100644
--- a/Source/cmForEachCommand.cxx
+++ b/Source/cmForEachCommand.cxx
@@ -16,6 +16,8 @@
 =========================================================================*/
 #include "cmForEachCommand.h"
 
+#include <cmsys/auto_ptr.hxx>
+
 bool cmForEachFunctionBlocker::
 IsFunctionBlocked(const cmListFileFunction& lff, cmMakefile &mf,
                   cmExecutionStatus &inStatus)
@@ -116,6 +118,10 @@ bool cmForEachCommand
     this->SetError("called with incorrect number of arguments");
     return false;
     }
+  if(args.size() > 1 && args[1] == "IN")
+    {
+    return this->HandleInMode(args);
+    }
   
   // create a function blocker
   cmForEachFunctionBlocker *f = new cmForEachFunctionBlocker();
@@ -197,3 +203,45 @@ bool cmForEachCommand
   return true;
 }
 
+//----------------------------------------------------------------------------
+bool cmForEachCommand::HandleInMode(std::vector<std::string> const& args)
+{
+  cmsys::auto_ptr<cmForEachFunctionBlocker> f(new cmForEachFunctionBlocker());
+  f->Args.push_back(args[0]);
+
+  enum Doing { DoingNone, DoingLists, DoingItems };
+  Doing doing = DoingNone;
+  for(unsigned int i=2; i < args.size(); ++i)
+    {
+    if(doing == DoingItems)
+      {
+      f->Args.push_back(args[i]);
+      }
+    else if(args[i] == "LISTS")
+      {
+      doing = DoingLists;
+      }
+    else if(args[i] == "ITEMS")
+      {
+      doing = DoingItems;
+      }
+    else if(doing == DoingLists)
+      {
+      const char* value = this->Makefile->GetDefinition(args[i].c_str());
+      if(value && *value)
+        {
+        cmSystemTools::ExpandListArgument(value, f->Args, true);
+        }
+      }
+    else
+      {
+      cmOStringStream e;
+      e << "Unknown argument:\n" << "  " << args[i] << "\n";
+      this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
+      return true;
+      }
+    }
+
+  this->Makefile->AddFunctionBlocker(f.release()); // TODO: pass auto_ptr
+  return true;
+}