ENH: Better handling of mismatched blocks

If a logical block terminates with mismatching arguments we previously
failed to remove the function blocker but replayed the commands anyway,
which led to cases in which we failed to report the mismatch (return
shortly after the ending command).  The recent refactoring of function
blocker deletion changed this behavior to produce an error on the ending
line by not blocking the command.  Furthermore, the function blocker
would stay in place and complain at the end of every equal-level block
of the same type.

This teaches CMake to treat the begin/end commands (if/endif, etc.) as
correct and just warns when the arguments mismatch.  The change allows
cases in which CMake 2.6.2 silently ignored a mismatch to run as before
but with a warning.

Source/cmForEachCommand.cxx

@@ -31,7 +31,8 @@ IsFunctionBlocked(const cmListFileFunction& lff, cmMakefile &mf,
     if (!this->Depth) 
       {
       // Remove the function blocker for this scope or bail.
-      cmsys::auto_ptr<cmFunctionBlocker> fb(mf.RemoveFunctionBlocker(lff));
+      cmsys::auto_ptr<cmFunctionBlocker>
+        fb(mf.RemoveFunctionBlocker(this, lff));
       if(!fb.get()) { return false; }
 
       // at end of for each execute recorded commands

Source/cmFunctionCommand.cxx

@@ -222,7 +222,7 @@ IsFunctionBlocked(const cmListFileFunction& lff, cmMakefile &mf,
       mf.AddCommand(f);
 
       // remove the function blocker now that the function is defined
-      mf.RemoveFunctionBlocker(lff);
+      mf.RemoveFunctionBlocker(this, lff);
       return true;
       }
     else

Source/cmIfCommand.cxx

@@ -39,7 +39,8 @@ IsFunctionBlocked(const cmListFileFunction& lff,
     if (!this->ScopeDepth) 
       {
       // Remove the function blocker for this scope or bail.
-      cmsys::auto_ptr<cmFunctionBlocker> fb(mf.RemoveFunctionBlocker(lff));
+      cmsys::auto_ptr<cmFunctionBlocker>
+        fb(mf.RemoveFunctionBlocker(this, lff));
       if(!fb.get()) { return false; }
 
       // execute the functions for the true parts of the if statement

Source/cmMacroCommand.cxx

@@ -266,7 +266,7 @@ IsFunctionBlocked(const cmListFileFunction& lff, cmMakefile &mf,
       mf.AddCommand(f);
 
       // remove the function blocker now that the macro is defined
-      mf.RemoveFunctionBlocker(lff);
+      mf.RemoveFunctionBlocker(this, lff);
       return true;
       }
     else

Source/cmMakefile.cxx

@@ -2422,7 +2422,8 @@ void cmMakefile::AddFunctionBlocker(cmFunctionBlocker* fb)
 }
 
 cmsys::auto_ptr<cmFunctionBlocker>
-cmMakefile::RemoveFunctionBlocker(const cmListFileFunction& lff)
+cmMakefile::RemoveFunctionBlocker(cmFunctionBlocker* fb,
+                                  const cmListFileFunction& lff)
 {
   // Find the function blocker stack barrier for the current scope.
   // We only remove a blocker whose index is not less than the barrier.
@@ -2438,8 +2439,20 @@ cmMakefile::RemoveFunctionBlocker(const cmListFileFunction& lff)
     {
     std::vector<cmFunctionBlocker*>::iterator pos =
       this->FunctionBlockers.begin() + (i - 1);
-    if ((*pos)->ShouldRemove(lff, *this))
+    if (*pos == fb)
       {
+      // Warn if the arguments do not match, but always remove.
+      if(!(*pos)->ShouldRemove(lff, *this))
+        {
+        cmListFileContext const& lfc = fb->GetStartingContext();
+        cmOStringStream e;
+        e << "A logical block opening on the line\n"
+          << "  " << lfc << "\n"
+          << "closes on the line\n"
+          << "  " << lff << "\n"
+          << "with mis-matching arguments.";
+        this->IssueMessage(cmake::AUTHOR_WARNING, e.str());
+        }
       cmFunctionBlocker* b = *pos;
       this->FunctionBlockers.erase(pos);
       return cmsys::auto_ptr<cmFunctionBlocker>(b);

Source/cmMakefile.h

@@ -95,7 +95,7 @@ public:
    * This returns ownership of the function blocker object.
    */
   cmsys::auto_ptr<cmFunctionBlocker>
-  RemoveFunctionBlocker(const cmListFileFunction& lff);
+  RemoveFunctionBlocker(cmFunctionBlocker* fb, const cmListFileFunction& lff);
 
   /** Push/pop a lexical (function blocker) barrier automatically.  */
   class LexicalPushPop

Source/cmWhileCommand.cxx

@@ -33,7 +33,8 @@ IsFunctionBlocked(const cmListFileFunction& lff, cmMakefile &mf,
     if (!this->Depth) 
       {
       // Remove the function blocker for this scope or bail.
-      cmsys::auto_ptr<cmFunctionBlocker> fb(mf.RemoveFunctionBlocker(lff));
+      cmsys::auto_ptr<cmFunctionBlocker>
+        fb(mf.RemoveFunctionBlocker(this, lff));
       if(!fb.get()) { return false; }
 
       std::string errorString;