https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86584
Bug ID: 86584 Summary: Incorrect -Wsequence-point warning on structure member Product: gcc Version: 7.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: rusty at rustcorp dot com.au Target Milestone: --- gcc (Ubuntu 7.3.0-16ubuntu3) 7.3.0, x86-64. Also in gcc-8 (Ubuntu 8.1.0-1ubuntu1) 8.1.0. I have a macro which does an assignment, and also hands the address of the same var to the function. The reduced version is below: it gives a spurious warning when the var involved is a struct member: struct s { int f; }; void func(int *f, int); int main(void) { struct s s; int f; /* bad-warning-gcc.c:13:17: warning: operation on ‘s.f’ may be undefined [-Wsequence-point] */ func(&s.f, s.f = 1); /* No warning for this */ func(&f, f = 1); return 0; }