On Fri, 9 Dec 2016, Richard Biener wrote: > Right, 'used' thwarts IPA on the callee side only. noclone and noinline are > attributes affecting the caller side but we indeed miss attributes for the > properties you mention above. I suppose adding a catch-all attribute for > caller side effects (like we have 'used' for the callee side) would be a good > idea.
For general uses, i.e. for testcases that ought to be portable across different compilers, I believe making a call through a volatile pointer already places a sufficient compiler barrier to prevent both caller- and callee-side analysis. That is, where you have int foo(int); foo(arg); you could transform it to int foo(int); int (* volatile vpfoo)(int) = foo; vpfoo(arg); While this also has an effect of forcing the call to be indirect, I think usually that should be acceptable. But for uses in the gcc testsuite, I believe an attribute is still needed. Alexander
