I think we want to move *away* from inline functions in headers and towards link-time inlining, in the interests of modularity: if one component of GCC cannot see the internals of another component at compile time, it cannot use them but must use the actual interface of that component, but inline functions often require internals to be visible. tm.h is a case in point of exposing internals, as it exports a great many macros that are really part of the internals of a particular back end and so should only be visible in that back end (including the generated insn-*.c files) and not in the RTL passes, so tempting people to put e.g. TARGET_64BIT conditionals outside of config/ (TARGET_64BIT should be private to the individual back ends).
See <http://gcc.gnu.org/ml/gcc-patches/2010-06/msg02244.html> for example on the direction of moving away from inline functions in headers. -- Joseph S. Myers jos...@codesourcery.com
