From: Kristofer.Wempa@xxxxxxx To: gcc-help@xxxxxxxxxxx Subject: Need clarification on mixing GCC 4.5 with earlier versions (Re-formatted) I am looking to build an entire set of tools using GCC 4.5 for SLES10, which is based on GCC 4.1.2. According to the GCC 4.4 release notes, there is an ABI change that causes it to be incompatible with earlier GCC versions. My initial plan was to build GCC 4.5 and then build the remaining software with 4.5 using the "-fabi-version" option to make it generate binaries compatible with GCC 4.1.2. However, the GCC man page and other documentation I have come across says that GCC 4.4 and 4.5 still use version 2.0 of the ABI, which was introduced in GCC 3.4. Now, I.m confused. If GCC 4.4 introduces an ABI change, then how can it still be the same ABI version as the earlier GCC versions ? It sounds like there is a minor change to the ABI, but that they still want to consider it compatible with the previous ABI version. Can somebody please clarify this for me ? I have bounced this off of a couple of other people who are familiar with these concepts and they also agree that it's unclear. Any help would be greatly appreciated. Kris Wempa