Re: [PATCH5 PR gdb/16959] gdb hangs in infinite recursion

[Weimin Pan <weimin dot pan at oracle dot com>]

On 3/29/2018 10:08 PM, Simon Marchi wrote:
> On 2018-03-28 16:44, Weimin Pan wrote:
> > The original problem was fixed (see related PR 22242). But using a 
> > typedef
> > as the declared type for a static member variable, as commented in 
> > this PR,
> > is still causing gdb to get into infinite loop when printing the static
> > member's value. This problem can be reproduced as follows:
> >
> > % cat t.cc
> > class A {
> >     typedef A type;
> > public:
> >     bool operator==(const type& other) { return true; }
> >
> >     static const type INSTANCE;
> > };
> >
> > const A A::INSTANCE;
> >
> > int main() {
> >     A a;
> >     if (a == A::INSTANCE) {
> >         return -1;
> >     }
> >     return 0;
> > }
> > % g++ -g t.cc
> > % gdb -ex "start" -ex "p a" a.out
> >
> > The fix is rather trivial - in cp_print_static_field(), should call
> > check_typedef() to get the static member's real type and use it to
> > check whether it's a struct or an array.
> >
> > As Simon suggested, I've added a new test case to the testsuite
> > and am passing the original type, not the real type, as argument
> > to both cp_print_value_fields() and val_print().
> >
> > Re-tested on both aarch64-linux-gnu and amd64-linux-gnu. No regressions.
>
> Hi Weimin,
>
> Could you change the title to something more descriptive about what 
> the change/fix is, rather than the problem being fixed?  For example, 
> "Fix infinite recursion when printing static member with typedef".
>
> It is ok to push with that fixed (feel free to ask if you still need 
> some guidance).
>
> Thanks!
>
> Simon
Hi Simon,

I just got started to work on this. Here is what I've done (I followed
your lead to creat a different remote name):

% git add <newfile>
% git commit -a
% git remote add upstream ssh://sourceware.org/git/binutils-gdb.git
% git fetch upstream

I have a few questions:

 * Do I need to do a "git merge" after "git fetch"? Or can I just
   do "git pull" which is equivalent to "git fetch;git merge"?
   (I was a Mercurial(hg) user, its typical workflow is like:
    hg in; do work; hg commit; hg pull; hg rebase(if needed); hg push)

 * In your previous email, you said:

   Make sure you inserted the ChangeLog entries in the actual ChangeLog 
files
   and amended your commit

   It seems the "git commit -a" command will contain all the changes, 
including
   those in ChangeLog files. Why do I have to insert the entries?

 * Changing the commit title to be be more descriptive:

   So I need to use "git commit --amend" to change the title?

Thanks very much for your help.

Weimin