On Thu, Feb 16, 2012 at 12:49 PM, Christian Bruel <christian.br...@st.com> wrote: > >> >> >> On 02/15/2012 06:03 PM, Joseph S. Myers wrote: >>> On Wed, 15 Feb 2012, Christian Bruel wrote: >>> >>>> Removal of this NOP_EXPR if !CAN_HAVE_LOCATION_P fixes the problem. >>>> looks safe from my testing, because the loc is inserted using >>>> 'protected_set_expr_location', whereas no loc for a constant case >>>> doesn't seem to introduce new problems with the debugging information. >>>> But in case I also added a few paranoid gcc_assert. >>> >>> Is it safe to set TREE_NO_WARNING without that check? I'd have thought >>> the check was to avoid setting TREE_NO_WARNING on a shared node when >>> warnings are to be disabled in only one context where that node is used. > > In fact, we can't omit the TREE_NO_WARNING is !CAN_HAVE_LOCATION_P, the > tentative bellow causes a regression on middle-end/13325. > > What I'm unsure is why we couldn't have a TREE_NO_WARNING on a > !CAN_HAVE_LOCATION_P. This seems necessary on some cases without using a > NOP_EXPR.
You cannot have it on possibly shared tree nodes. CAN_HAVE_LOCATION_P tree nodes are not shared (the reverse is not true). Richard.
