[Bug fortran/43289] Missed constraint C1271a: Referrencing VOLATILE variable in PURE subprogram

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43289

--- Comment #4 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-12-11 17:17:18 UTC ---
Created attachment 26047
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26047
Draft patch w/ test case

Patch TODO: Handle implicit pure, cf. PR 51502.

The error location is not ideal, but finding the expression locus requires
adding this check at every place where sym->referenced.