On Fri, May 5, 2017 at 11:27 PM, Bernhard Reutner-Fischer <rep.dot....@gmail.com> wrote: > On 4 May 2017 14:12:04 CEST, Richard Biener <richard.guent...@gmail.com> > wrote: > >>nonoverlapping_component_refs_of_decl_p >>should simply skip ARRAY_REFs - but I also see there: >> >> /* ??? We cannot simply use the type of operand #0 of the refs here >> as the Fortran compiler smuggles type punning into COMPONENT_REFs >> for common blocks instead of using unions like everyone else. */ >> tree type1 = DECL_CONTEXT (field1); >> tree type2 = DECL_CONTEXT (field2); >> >>so you probably can't simply use TREE_TYPE (outer_ref) for type >>compatibility. >>You also may not use types_compatible_p here as for LTO that is _way_ >>too >>lax for aggregates. The above uses >> >> /* We cannot disambiguate fields in a union or qualified union. */ >> if (type1 != type2 || TREE_CODE (type1) != RECORD_TYPE) >> return false; >> >>so you should also bail out on unions here, rather than the check you >>do later. >> >>You seem to rely on getting an access_fn entry for each >>handled_component_p. >>It looks like this is the case -- we even seem to stop at unions (with >>the same >>fortran "issue"). I'm not sure that's the best thing to do but you >>rely on that. > > Is there a PR for the (IIUC) common as union? > Maybe around > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=41227 > COMMON block, BIND(C) and LTO interoperability issues
I'm not sure, this is Erics code so maybe he remembers. Richard. > Thanks
