From 46b738ffc2bf27c1c0bf0492f8c646c4496819dc Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 17 Feb 2022 22:45:34 -0500 Subject: Suppress warning about stack_base_ptr with late-model GCC. GCC 12 complains that set_stack_base is storing the address of a local variable in a long-lived pointer. This is an entirely reasonable warning (indeed, it just helped us find a bug); but that behavior is intentional here. We can work around it by using __builtin_frame_address(0) instead of a specific local variable; that produces an address a dozen or so bytes different, in my testing, but we don't care about such a small difference. Maybe someday a compiler lacking that function will start to issue a similar warning, but we'll worry about that when it happens. Patch by me, per a suggestion from Andres Freund. Back-patch to v12, which is as far back as the patch will go without some pain. (Recently-established project policy would permit a back-patch as far as 9.2, but I'm disinclined to expend the work until GCC 12 is much more widespread.) Discussion: https://postgr.es/m/3773792.1645141467@sss.pgh.pa.us --- src/backend/utils/init/miscinit.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'src/backend/utils/init/miscinit.c') diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c index cca9704d2d7..fafeb4b7d0b 100644 --- a/src/backend/utils/init/miscinit.c +++ b/src/backend/utils/init/miscinit.c @@ -93,13 +93,12 @@ InitPostmasterChild(void) IsUnderPostmaster = true; /* we are a postmaster subprocess now */ /* - * Set reference point for stack-depth checking. We re-do that even in the - * !EXEC_BACKEND case, because there are some edge cases where processes - * are started with an alternative stack (e.g. starting bgworkers when - * running postgres using the rr debugger, as bgworkers are launched from - * signal handlers). + * Set reference point for stack-depth checking. This might seem + * redundant in !EXEC_BACKEND builds; but it's not because the postmaster + * launches its children from signal handlers, so we might be running on + * an alternative stack. */ - set_stack_base(); + (void) set_stack_base(); InitProcessGlobals(); -- cgit v1.2.3