Question on adding an option control to libcpp

[Qing Zhao]

Hi, David,

this is helpful.

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.gnu.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
>