Re: Question on adding an option control to libcpp

[David Malcolm <dmalcolm at redhat dot com>]

On Tue, 2019-05-28 at 15:08 -0500, Qing Zhao wrote:
> Hi, David,
> 
> for this new option, do I need to add a new testing case for it?

Yes please.  Ideally we should add at least one test case for any new
option, especially if it's easy to test for.

> if so, where should I put this new testing case?

It's probably testable for in DejaGnu with a testcase that sets the
maximum depth to some very low limit (say just a single include), and
then have a testcase that has a depth of two.

Or something like that, though DejaGnu's line-based directives aren't a
perfect fit for diagnostics occurring in included files.

Maybe such tests should live in gcc/testsuite/c-c++-common/cpp/

I think there's something similar in:
  gcc/testsuite/c-c++-common/inc-from-1.c

Dave

> thanks.
> 
> Qing
> > On May 24, 2019, at 1:47 PM, David Malcolm <dmalcolm@redhat.com>
> > wrote:
> > 
> > On Fri, 2019-05-24 at 11:59 -0500, Qing Zhao wrote:
> > > Hi, 
> > > 
> > > in order to fix PR90581: (provide an option to adjust the maximum
> > > depth of nested #include)
> > > 
> > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90581 <https://gcc.g
> > > nu.o
> > > rg/bugzilla/show_bug.cgi?id=90581>
> > > 
> > > we need to add a new option to preprocessor.  where should I put
> > > this
> > > option?
> > > 
> > > I tried to add a new option into:
> > > 
> > > gcc/c-family/c.opt
> > > 
> > > [qinzhao@localhost c-family]$ git diff c.opt
> > > diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
> > > index 046d489..4f237b6 100644
> > > --- a/gcc/c-family/c.opt
> > > +++ b/gcc/c-family/c.opt
> > > @@ -1598,6 +1598,10 @@ flocal-ivars
> > > ObjC ObjC++ Var(flag_local_ivars) Init(1)
> > > Allow access to instance variables as if they were local
> > > declarations within instance method implementati
> > > 
> > > +finclude-nest-limit=
> > > +C ObjC C++ ObjC++ Joined RejectNegative UInteger
> > > Var(include_nest_limit) Init(200)
> > > +Set the maximum number of depth of nested #include.
> > > +
> > > 
> > > However, don’t know how to refer this new variable
> > > “include_nest_limit” from libcpp.
> > > 
> > 
> > You probably want to add a new field to cpp_options, and copy over
> > the
> > value from the GCC options to the new field; see e.g.
> > c_common_handle_option where various cases write to fields of
> > cpp_opts.
> > 
> > Hope this is helpful
> > Dave
> 
>