ENH: Make add_custom_command interpret relative OUTPUT locations with respect to the build tre instead of the source tree. This can greatly simplify user code since generating a file will not need to reference CMAKE_CURRENT_BINARY_DIR. The new behavior is what users expect 99% of the time.

1 files changed, 11 insertions, 1 deletions

diff --git a/Source/cmAddCustomCommandCommand.cxx b/Source/cmAddCustomCommandCommand.cxx
index 3161ef1..5912a79 100644
--- a/Source/cmAddCustomCommandCommand.cxx
+++ b/Source/cmAddCustomCommandCommand.cxx
@@ -152,7 +152,17 @@ bool cmAddCustomCommandCommand
         case doing_outputs:
           if (!cmSystemTools::FileIsFullPath(copy.c_str()))
             {
-            filename = this->Makefile->GetStartDirectory();
+            // This is an output to be generated, so it should be
+            // under the build tree.  CMake 2.4 placed this under the
+            // source tree.  However the only case that this change
+            // will break is when someone writes
+            //
+            //   add_custom_command(OUTPUT out.txt ...)
+            //
+            // and later references "${CMAKE_CURRENT_SOURCE_DIR}/out.txt".
+            // This is fairly obscure so we can wait for someone to
+            // complain.
+            filename = this->Makefile->GetCurrentOutputDirectory();
             filename += "/";
             }
           filename += copy;