https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88273
Martin Liška <marxin at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target| |powerpc-*-linux-gnu
Status|UNCONFIRMED |NEW
Keywords| |needs-bisection
Last reconfirmed| |2019-01-03
CC| |marxin at gcc dot gnu.org
Host| |x86_64-pc-linux-gnu
Ever confirmed|0 |1
Known to fail| |9.0
--- Comment #9 from Martin Liška <marxin at gcc dot gnu.org> ---
Slightly cleaned up test-case:
$ cat /home/marxin/Programming/testcases/pr88273-2.c
typedef struct {
int b[4];
} c;
void* d;
unsigned e;
inline int h(void *i, int p2, int j) {
if (j < 0 || e < j) {
int copy = j - e;
i += e - p2;
__builtin_memcpy(d, i, copy);
e = copy;
}
}
void a() {
int g = h(&g, 0, sizeof(c));
c vrsave;
h(&vrsave, 33 * sizeof(c), -1);
}
So the warning is triggered for the cross compiler from here:
$ Breakpoint 5, warning_at (location=location@entry=2147483704,
opt=opt@entry=171, gmsgid=gmsgid@entry=0x15a3448 "%G%qD offset %s is out of the
bounds [0, %wu] of object %qD with type %qT") at ../../gcc/diagnostic.c:1289
1289 {
(gdb) bt
#0 warning_at (location=location@entry=2147483704, opt=opt@entry=171,
gmsgid=gmsgid@entry=0x15a3448 "%G%qD offset %s is out of the bounds [0, %wu] of
object %qD with type %qT") at ../../gcc/diagnostic.c:1289
#1 0x0000000000a39dc3 in (anonymous namespace)::maybe_diag_offset_bounds
(loc=2147483704, call=<gimple_call 0x7ffff6b411c8>, func=<function_decl
0x7ffff6a23500 __builtin_memcpy>, strict=<optimized out>, expr=<optimized out>,
ref=...) at ../../gcc/wide-int.h:831
#2 0x0000000000a3a9d9 in (anonymous namespace)::maybe_diag_offset_bounds
(ref=..., expr=<ssa_name 0x7ffff6b3dbd0>, strict=0, func=<optimized out>,
call=<gimple_call 0x7ffff6b411c8>, loc=2147483704) at
../../gcc/gimple-ssa-warn-restrict.c:1586
#3 check_bounds_or_overlap (call=<gimple_call 0x7ffff6b411c8>, dst=<ssa_name
0x7ffff6b3da68>, src=<ssa_name 0x7ffff6b3dbd0>, dstsize=<optimized out>,
srcsize=<optimized out>, bounds_only=<optimized out>) at
../../gcc/gimple-ssa-warn-restrict.c:1851
#4 0x0000000000a3c718 in (anonymous
namespace)::wrestrict_dom_walker::check_call (this=<optimized out>,
call=<gimple_call 0x7ffff6b411c8>) at ../../gcc/gimple-ssa-warn-restrict.c:1814
#5 (anonymous namespace)::wrestrict_dom_walker::before_dom_children
(this=<optimized out>, bb=<optimized out>) at
../../gcc/gimple-ssa-warn-restrict.c:105
#6 0x00000000013256d8 in dom_walker::walk (this=this@entry=0x7fffffffd720,
bb=<basic_block 0x7ffff6b0ab60 (4)>) at ../../gcc/domwalk.c:373
#7 0x0000000000a31c38 in (anonymous namespace)::pass_wrestrict::execute
(this=<optimized out>, fun=0x7ffff6b360b0) at
../../gcc/gimple-ssa-warn-restrict.c:119
#8 0x0000000000be2885 in execute_one_pass (pass=<opt_pass* 0x1d49510
"wrestrict"(188)>) at ../../gcc/passes.c:2483
#9 0x0000000000be3008 in execute_pass_list_1 (pass=<opt_pass* 0x1d49510
"wrestrict"(188)>) at ../../gcc/passes.c:2569
#10 0x0000000000be301a in execute_pass_list_1 (pass=<opt_pass* 0x1d47020
"*all_optimizations"(-1)>) at ../../gcc/passes.c:2570
#11 0x0000000000be3059 in execute_pass_list (fn=0x7ffff6b360b0, pass=<optimized
out>) at ../../gcc/passes.c:2580
#12 0x00000000008cd5cb in cgraph_node::expand (this=<cgraph_node * const
0x7ffff698f5a0 "a"/3>) at ../../gcc/context.h:48
#13 0x00000000008ce5a4 in expand_all_functions () at
../../gcc/cgraphunit.c:2334
#14 symbol_table::compile (this=0x7ffff6991000) at ../../gcc/cgraphunit.c:2685
#15 0x00000000008d0bed in symbol_table::compile (this=0x7ffff6991000) at
../../gcc/cgraphunit.c:2863
#16 symbol_table::finalize_compilation_unit (this=0x7ffff6991000) at
../../gcc/cgraphunit.c:2863
#17 0x0000000000cb9b4b in compile_file () at ../../gcc/toplev.c:481
#18 0x00000000007522c4 in do_compile () at ../../gcc/toplev.c:2176
#19 toplev::main (this=this@entry=0x7fffffffd93e, argc=<optimized out>,
argc@entry=23, argv=<optimized out>, argv@entry=0x7fffffffda38) at
../../gcc/toplev.c:2311
#20 0x00000000007545db in main (argc=23, argv=0x7fffffffda38) at
../../gcc/main.c:39
For the following gimple IL:
$ (gdb) p debug_gimple_stmt(call)
No symbol "call" in current context.
(gdb) p debug_function(cfun->decl,0)
a ()
{
void * i;
void * i;
int D.2622;
struct c vrsave;
int g;
unsigned int e.0_5;
void * pretmp_10;
unsigned int _12;
unsigned int prephitmp_13;
void * pretmp_14;
void * prephitmp_17;
unsigned int _19;
unsigned int _21;
<bb 2> [local count: 1073741824]:
e.0_5 = e;
pretmp_10 = d;
if (e.0_5 <= 15)
goto <bb 3>; [50.00%]
else
goto <bb 4>; [50.00%]
<bb 3> [local count: 536870913]:
_12 = 16 - e.0_5;
i_15 = &g + e.0_5;
__builtin_memcpy (pretmp_10, i_15, _12);
e = _12;
pretmp_14 = d;
<bb 4> [local count: 1073741824]:
# prephitmp_13 = PHI <_12(3), e.0_5(2)>
# prephitmp_17 = PHI <pretmp_14(3), pretmp_10(2)>
_19 = ~prephitmp_13;
_21 = prephitmp_13 + 4294966768;
i_22 = &vrsave + _21;
__builtin_memcpy (prephitmp_17, i_22, _19);
e = _19;
g ={v} {CLOBBER};
vrsave ={v} {CLOBBER};
return;
}
I can confirm the warning is false, because the problematic __builtin_memcpy
for which we trigger the warning:
__builtin_memcpy (prephitmp_17, i_22, _19);
and complains about i_22, but this one should be fine (with a reasonable
initial value of global variable 'e').
Martin: can you please take a look?
