On Thu, Dec 15, 2011 at 3:44 PM, Ingo Weinhold <ingo_weinhold@xxxxxx> wrote: > For building gcc a subset of headers/config, headers/posix, and headers/os is > used. Which headers exactly is not exactly trivial to determine. Binary > incompatible changes in those may require a rebuild of the tools, though, as > written above, should not normally be made. Right - I believe some of those headers may also have GCC version checking logic to ensure binary compatibility remains in GCC2 while allowing "bustage" with GCC4? Should we just err on the side of caution then and assume that any changes to the contents in those header directories should cause a recompilation of the cross-tools on a buildslave? - Urias