Richard Sandiford <rdsandif...@googlemail.com> writes: > The main thing keeping zero-precision wide-ints alive was void_zero_node, > a tree used in the C and C++ frontends that has type VOID_TYPE but code > INTEGER_CST. > > Richard B. asked me to replace the INTEGER_CST with a new constant type, > here called VOID_CST. Most of it is straight-forward. The one perhaps > controversial bit is that C++ uses void_(zero_)node to represent dummy > objects when e.g. taking the address of a member function without an > associated object. IIUC the node used in this situation needs to be > distinct from anything that could occur in user code and therefore couldn't > be a simple null pointer. > > This reaches the gimplifier in cases like > g++.old-deja/g++.brendan/operators4.C. I chose to handle it in the > gimplifier, since void_zero_node was previously handled there too, > although perhaps by accident. If you object strongly to this then > I'll need pretty detailed instructions about what to do instead, > i.e. exactly which parts of the C++ front end need to be changed > in order for dummy objects never to escape. > > I wasn't sure if any errors could ever print void_(zero_)node, > so I tested the pretty-printing routines by adding fake errors > after convert_to_void, etc. > > Tested on x86_64-linux-gnu. OK to install?
Forgot to say that I also tested boostrap-ubsan and that the wide-int.h shift-by-64 errors were gone.
