On Fri, Jul 02, 2021 at 11:46:46AM -0400, Jason Merrill wrote: > On 7/1/21 6:16 AM, Trevor Saunders wrote: > > On Wed, Jun 30, 2021 at 11:13:23AM -0400, David Malcolm wrote: > > > On Wed, 2021-06-30 at 01:35 -0400, Trevor Saunders wrote: > > > > This makes it possible to assert if input_location is used during the > > > > lifetime > > > > of a scope. This will allow us to find places that currently use it > > > > within a > > > > function and its callees, or prevent adding uses within the lifetime > > > > of a > > > > function after all existing uses are removed. > > > > > > > > bootstrapped and regtested on x86_64-linux-gnu, ok? > > > > > > > > Trev > > > > > > [...snip...] > > > > > > > diff --git a/gcc/diagnostic.c b/gcc/diagnostic.c > > > > index d58586f2526..3f68d1d79eb 100644 > > > > --- a/gcc/diagnostic.c > > > > +++ b/gcc/diagnostic.c > > > > @@ -1835,7 +1835,7 @@ internal_error (const char *gmsgid, ...) > > > > auto_diagnostic_group d; > > > > va_list ap; > > > > va_start (ap, gmsgid); > > > > - rich_location richloc (line_table, input_location); > > > > + rich_location richloc (line_table, UNKNOWN_LOCATION); > > > > diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_ICE); > > > > va_end (ap); > > > > > > I actually make use of this in the analyzer: the analyzer sets > > > input_location to stmt->location when analyzing a given stmt - that > > > way, if the analyzer ICEs, the ICE is shown at the code construct that > > > crashed the analyzer. > > > > > > This behavior is useful to me, and would be lost with the proposed > > > patch. > > > > I made this change because otherwise if the compiler ICE's while access > > to input_location is blocked we end up infinitely recursing complaining > > we can't access it while trying to say where the last error was. I was > > nervous about the change before, and now I agree we need something > > else. > > How about allowing a scope (like internal_error) to explicitly un-poison the > variable?
The only reason I didn't add such a thing was not having a need for it, and not wanting to worry about the possible complexity of combining that with allowing nested poisoning with a refcount. However if people think it would be useful to have this I'm happy to add it to a v2, otherwise I'm happy to just use this locally for finding code using input_location, or other globals. > Separately, all the location_t (input_location) changes are pretty clunky, > can we make that conversion part of the macro? Currently its not a macro, while we could change that, defining it as #define input_location ((location_t &) input_location_real) seems a bit sneaky, but I think you have to define it that way if you want to avoid updating all the assignments to input_location? Thanks Trev > > Jason >
