>>>>> "Basile" == Basile Starynkevitch <bas...@starynkevitch.net> writes:
Basile> My understanding of the description of the tag GTY option in Basile> http://gcc.gnu.org/onlinedocs/gccint/GTY-Options.html#GTY-Options Basile> is that a given discriminated union case can have several Basile> tags. It seems like a reasonable feature, but I didn't see any text there indicating that this is already supported. Basile> struct meltspecial_st Basile> GTY ((tag ("OBMAG_SPEC_FILE"), Basile> tag ("OBMAG_SPEC_RAWFILE"), Basile> tag ("OBMAG_SPEC_MPFR"), Basile> tag ("OBMAG_SPECPPL_COEFFICIENT"), Basile> tag ("OBMAG_SPECPPL_LINEAR_EXPRESSION"), Basile> tag ("OBMAG_SPECPPL_CONSTRAINT"), Basile> tag ("OBMAG_SPECPPL_CONSTRAINT_SYSTEM"), Basile> tag ("OBMAG_SPECPPL_GENERATOR"), Basile> tag ("OBMAG_SPECPPL_GENERATOR_SYSTEM"), Basile> tag ("OBMAG_SPECPPL_POLYHEDRON")) Basile> ) u_special; One thing you can do here is provide a "desc" tag for the union that collapses all these tags to a single tag. Instead of: GTY ((desc ("%0.u_discr->object_magic"))) You would have: int magic_for_ggc (int magic) { if (magic == OBMAG_SPEC_FILE || magic == OBMAG_SPEC_RAWFILE || ...) return OBMAG_SPEC_RAWFILE; return magic; } .. and GTY ((desc ("magic_for_ggc (%0.u_discr->object_magic)"))) Tom
