gcc 4.0 ICEs after replacing a call via a function pointer with
a call to a noreturn function (unless that call falls through
to the exit block). The expected fake edge to the exit block
is not added after modifying the CALL_EXPR.
I'm not up to speed on gimple yet, so I'm just filing this for info.
It's a 4.0 regression.
$ cat foo.c
extern void foo (void) __attribute__((noreturn));
int n;
void
g (void)
{
void (*f) (void) = foo;
if (n)
f ();
n = 1;
}
$ gcc -O foo.c
foo.c: In function 'g':
foo.c:11: error: verify_flow_info: Incorrect fallthru 2->3
foo.c:11: error: wrong insn in the fallthru edge
(barrier 17 16 18)
foo.c:11: internal compiler error: in rtl_verify_flow_info, at cfgrtl.c:2201
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
...or (shorter, but rather less likely)...
$ cat bar.c
extern void foo (void) __attribute__((noreturn));
void g (void)
{
void (*f) (void) = foo;
f ();
f ();
}
$ gcc -O bar.c
bar.c: In function 'g':
bar.c:4: error: Control flow in the middle of basic block 0
bar.c:4: error: Control flow in the middle of basic block 0
bar.c:4: internal compiler error: verify_flow_info failed
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
--
Summary: [4.0 Regression] function pointer propagation fails for
noreturn functions
Product: gcc
Version: unknown
Status: UNCONFIRMED
Keywords: ice-on-valid-code
Severity: normal
Priority: P2
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: rsandifo at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19484
