I wrote: > It looks like SLRU_PAGE_EMPTY has (by chance, or deliberately) > the numeric value of zero, so I guess the majority of our BF > animals are understanding this as "address != NULL". But that > doesn't look like a useful test to be making.
In hopes of noticing whether there are other similar thinkos, I permuted the order of the SlruPageStatus enum values, and now I get the expected warnings from gcc: In file included from ../../../../src/include/postgres.h:45, from slru.c:59: slru.c: In function ‘SimpleLruWaitIO’: slru.c:436:38: warning: comparison between pointer and integer Assert(&shared->page_status[slotno] != SLRU_PAGE_EMPTY); ^~ ../../../../src/include/c.h:862:9: note: in definition of macro ‘Assert’ if (!(condition)) \ ^~~~~~~~~ slru.c: In function ‘SimpleLruWritePage’: slru.c:717:43: warning: comparison between pointer and integer Assert(&ctl->shared->page_status[slotno] != SLRU_PAGE_EMPTY); ^~ ../../../../src/include/c.h:862:9: note: in definition of macro ‘Assert’ if (!(condition)) \ ^~~~~~~~~ So it looks like it's just these two places. regards, tom lane