https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71876
Bug ID: 71876
Summary: longjmp is miscompiled with -ffreestanding
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: bernd.edlinger at hotmail dot de
Target Milestone: ---
Even with -ffreestanding we handle some functions conservatively.
See special_function_p.
However, the function longjmp and siglongjmp are not handled conservatively
as the following test case illustrates:
cat test.c
int longjmp(void);
int bar(void)
{
return longjmp();
}
gcc -Wall -ffreestanding -O3 -S test.c
emits no warning, but resulting code is invalid (no ret):
bar:
.LFB0:
.cfi_startproc
subq $8, %rsp
.cfi_def_cfa_offset 16
call longjmp
.cfi_endproc
