Add the ALIAS target concept for libraries and executables.

* The ALIAS name must match a validity regex.
* Executables and libraries may be aliased.
* An ALIAS acts immutable. It can not be used as the lhs
  of target_link_libraries or other commands.
* An ALIAS can be used with add_custom_command, add_custom_target,
  and add_test in the same way regular targets can.
* The target of an ALIAS can be retrieved with the ALIASED_TARGET
  target property.
* An ALIAS does not appear in the generated buildsystem. It
  is kept separate from cmMakefile::Targets for that reason.
* A target may have multiple aliases.
* An ALIAS target may not itself have an alias.
* An IMPORTED target may not have an alias.
* An ALIAS may not be exported or imported.

1 files changed, 5 insertions, 0 deletions

diff --git a/Source/cmSetPropertyCommand.cxx b/Source/cmSetPropertyCommand.cxx
index b5e5225..4207860 100644
--- a/Source/cmSetPropertyCommand.cxx
+++ b/Source/cmSetPropertyCommand.cxx
@@ -244,6 +244,11 @@ bool cmSetPropertyCommand::HandleTargetMode()
   for(std::set<cmStdString>::const_iterator ni = this->Names.begin();
       ni != this->Names.end(); ++ni)
     {
+    if (this->Makefile->IsAlias(ni->c_str()))
+      {
+      this->SetError("can not be used on an ALIAS target.");
+      return false;
+      }
     if(cmTarget* target = this->Makefile->FindTargetToUse(ni->c_str()))
       {
       // Handle the current target.