ENH: Improve response to bad if or elseif

Previously bad arguments to an if() or elseif() would cause some
subsequent statements in the corresponding block to execute.  This
teaches CMake to stop processing commands with a fatal error.  It also
provides context to bad elseif() error messages.

1 files changed, 9 insertions, 2 deletions

diff --git a/Source/cmIfCommand.cxx b/Source/cmIfCommand.cxx
index 508a263..cbba2d3 100644
--- a/Source/cmIfCommand.cxx
+++ b/Source/cmIfCommand.cxx
@@ -76,6 +76,10 @@ IsFunctionBlocked(const cmListFileFunction& lff,
             }
           else
             {
+            // Place this call on the call stack.
+            cmMakefileCall stack_manager(&mf, this->Functions[c], status);
+            static_cast<void>(stack_manager);
+
             std::string errorString;
             
             std::vector<std::string> expandedArguments;
@@ -98,8 +102,10 @@ IsFunctionBlocked(const cmListFileFunction& lff,
               err += "(";
               err += errorString;
               err += ").";
-              cmSystemTools::Error(err.c_str());
-              return false;
+              mf.IssueMessage(cmake::FATAL_ERROR, err);
+              cmSystemTools::SetFatalErrorOccured();
+              mf.RemoveFunctionBlocker(lff);
+              return true;
               }
         
             if (isTrue)
@@ -204,6 +210,7 @@ bool cmIfCommand
     err += errorString;
     err += ").";
     this->SetError(err.c_str());
+    cmSystemTools::SetFatalErrorOccured();
     return false;
     }