https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119514
Bug ID: 119514 Summary: Incorrect warning: 'I' flag used with '%f' gnu_scanf format [-Wformat=] Product: gcc Version: 15.0 Status: UNCONFIRMED Keywords: diagnostic, false-positive Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: macro at orcam dot me.uk Target Milestone: --- Given this program: $ cat bz13988.c #include <stdio.h> int main (void) { double d; scanf ("%Ilf", &d); return 0; } $ I get this warning: $ gcc -Wall -O2 -o bz13988 bz13988.c bz13988.c: In function 'main': bz13988.c:7:14: warning: 'I' flag used with '%f' gnu_scanf format [-Wformat=] 7 | scanf ("%Ilf", &d); | ^ $ which according to Joseph Myers[1] has been incorrect since support for the 'I' scanf flag was added for real formats back in 2007. References: [1] "stdio-common: Also reject exp char w/o significand in i18n scanf [BZ #13988]", <https://inbox.sourceware.org/libc-alpha/6c4e01d3-5dde-464d-ca1b-84d94aea3...@redhat.com/>