Example: provenance_union_punning_1_global.c
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
int x=1;
typedef union { uintptr_t ui; int *p; } un;
int main() {
un u;
int *px = &x;
uintptr_t i = (uintptr_t)px;
u.ui = i;
int *p = u.p;
printf("Addresses: p=%p &x=%p\n",(void*)p,(void*)&x);
*p = 11; // is this free of undefined behaviour?
printf("x=%d *p=%d\n",x,*p);
return 0;
}
[link to test in Cerberus and Compiler Explorer]
Experimental data (what does this mean?)
gcc-8.1-O0 |   | Addresses: p=0x6009b8 &x=0x6009b8 x=11 *p=11
|
gcc-8.1-O2 |   | Addresses: p=0x600980 &x=0x600980 x=11 *p=11
|
gcc-8.1-O3 |   | Addresses: p=0x600980 &x=0x600980 x=11 *p=11
|
gcc-8.1-O2-no-strict-aliasing |   | Addresses: p=0x600980 &x=0x600980 x=11 *p=11
|
gcc-8.1-O3-no-strict-aliasing |   | Addresses: p=0x600980 &x=0x600980 x=11 *p=11
|
clang-6.0-O0 |   | Addresses: p=0x601038 &x=0x601038 x=11 *p=11
|
clang-6.0-O2 |   | Addresses: p=0x601038 &x=0x601038 x=11 *p=11
|
clang-6.0-O3 |   | Addresses: p=0x601038 &x=0x601038 x=11 *p=11
|
clang-6.0-O2-no-strict-aliasing |   | Addresses: p=0x601038 &x=0x601038 x=11 *p=11
|
clang-6.0-O3-no-strict-aliasing |   | Addresses: p=0x601038 &x=0x601038 x=11 *p=11
|
clang-6.0-UBSAN |   | Addresses: p=0x631b50 &x=0x631b50 x=11 *p=11
|
clang-6.0-ASAN |   | Addresses: p=0x716b60 &x=0x716b60 x=11 *p=11
|
clang-6.0-MSAN |   | Addresses: p=0x6b7af0 &x=0x6b7af0 x=11 *p=11
|
icc-19-O0 |   | Addresses: p=0x600ab0 &x=0x600ab0 x=11 *p=11
|
icc-19-O2 |   | Addresses: p=0x6046c0 &x=0x6046c0 x=11 *p=11
|
icc-19-O3 |   | Addresses: p=0x6046c0 &x=0x6046c0 x=11 *p=11
|
icc-19-O2-no-strict-aliasing |   | Addresses: p=0x6046c0 &x=0x6046c0 x=11 *p=11
|
icc-19-O3-no-strict-aliasing |   | Addresses: p=0x6046c0 &x=0x6046c0 x=11 *p=11
|
cerberus-concrete |   | BEGIN EXEC[0] Defined {value: "Specified(0)", stdout: "Addresses: p=<5>:60 &x=<5>:60\nx=11 *p=11\n", blocked: "false"} END EXEC[0] Time spent: 0.032592 seconds
|
cerberus-symbolic |   | exit codes: compile 0 / execute 1
cerberus: internal error, uncaught exception: Failure("TODO: union punning")
|
gcc-4.9-shadowprov |   | exit codes: compile 0 / execute 134
|
CHERI:MIPS-O0 |   | Addresses: p=0x30020 &x=0x30020 x=11 *p=11
|
CHERI:MIPS-O2 |   | Addresses: p=0x30020 &x=0x30020 x=11 *p=11
|
CHERI:MIPS-O2-no-strict-aliasing |   | Addresses: p=0x30020 &x=0x30020 x=11 *p=11
|
CHERI:CHERI-O0-uintcap-addr-exact-equals |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O2-uintcap-addr-exact-equals |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O2-no-strict-aliasing-uintcap-addr-exact-equals |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O0-uintcap-offset-exact-equals |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O2-uintcap-offset-exact-equals |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O2-no-strict-aliasing-uintcap-offset-exact-equals |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O0-uintcap-addr |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O2-uintcap-addr |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O2-no-strict-aliasing-uintcap-addr |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O0-uintcap-offset |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O2-uintcap-offset |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
CHERI:CHERI-O2-no-strict-aliasing-uintcap-offset |   | Addresses: p=0x120020010 &x=0x120020010 x=11 *p=11
|
RV-Match |   | Addresses: p=(nil) &x=(nil) x=11 *p=11
|
ch2o |   | provenance_union_punning_1_global.c:3:10: fatal error: inttypes.h: No such file or directory #include <inttypes.h> ^~~~~~~~~~~~ compilation terminated.
|
compcert-3.2 |   | Addresses: p=0x601038 &x=0x601038 x=11 *p=11
|
compcert-3.2-O |   | Addresses: p=0x601038 &x=0x601038 x=11 *p=11
|
compcert-3.2-interp |   | Time 0: calling main() --[step_internal_function]--> Time 1: in function main, statement px = &x; i = (unsigned int) px; u.ui = i; p = u.p; printf(__stringlit_1, (void *) p, (void *) &x); *p = 11; printf(__stringlit_2, x, *p); return 0; return 0; --[step_seq]--> Time 2: in function main, statement px = &x; i = (unsigned int) px; u.ui = i; p = u.p; printf(__stringlit_1, (void *) p, (void *) &x); *p = 11; printf(__stringlit_2, x, *p); return 0; --[step_seq]--> Time 3: in function main, statement px = &x; --[step_do_1]--> Time 4: in function main, expression px = &x --[red_var_local]--> Time 5: in function main, expression <loc px> = &x --[red_var_global]--> Time 6: in function main, expression <loc px> = &<loc x> --[red_addrof]--> Time 7: in function main, expression <loc px> = <ptr x> --[red_assign]--> Time 8: in function main, expression <ptr x> --[step_do_2]--> Time 9: in function main, statement /*skip*/; --[step_skip_seq]--> Time 10: in function main, statement i = (unsigned int) px; u.ui = i; p = u.p; printf(__stringlit_1, (void *) p, (void *) &x); *p = 11; printf(__stringlit_2, x, *p); return 0; --[step_seq]--> Time 11: in function main, statement i = (unsigned int) px; --[step_do_1]--> Time 12: in function main, expression i = (unsigned int) px --[red_var_local]--> Time 13: in function main, expression <loc i> = (unsigned int) px --[red_var_local]--> Time 14: in function main, expression <loc i> = (unsigned int) <loc px> --[red_rvalof]--> Time 15: in function main, expression <loc i> = (unsigned int) <ptr x> --[red_cast]--> Time 16: in function main, expression <loc i> = <ptr x> --[red_assign]--> Time 17: in function main, expression <ptr x> --[step_do_2]--> Time 18: in function main, statement /*skip*/; --[step_skip_seq]--> Time 19: in function main, statement u.ui = i; p = u.p; printf(__stringlit_1, (void *) p, (void *) &x); *p = 11; printf(__stringlit_2, x, *p); return 0; --[step_seq]--> Time 20: in function main, statement u.ui = i; --[step_do_1]--> Time 21: in function main, expression u.ui = i --[red_var_local]--> Time 22: in function main, expression <loc u>.ui = i --[red_rvalof]--> Time 23: in function main, expression <ptr u>.ui = i --[red_field_union]--> Time 24: in function main, expression <loc u> = i --[red_var_local]--> Time 25: in function main, expression <loc u> = <loc i> --[red_rvalof]--> Time 26: in function main, expression <loc u> = <ptr x> --[red_assign]--> Time 27: in function main, expression <ptr x> --[step_do_2]--> Time 28: in function main, statement /*skip*/; --[step_skip_seq]--> Time 29: in function main, statement p = u.p; printf(__stringlit_1, (void *) p, (void *) &x); *p = 11; printf(__stringlit_2, x, *p); return 0; --[step_seq]--> Time 30: in function main, statement p = u.p; --[step_do_1]--> Time 31: in function main, expression p = u.p --[red_var_local]--> Time 32: in function main, expression <loc p> = u.p --[red_var_local]--> Time 33: in function main, expression <loc p> = <loc u>.p --[red_rvalof]--> Time 34: in function main, expression <loc p> = <ptr u>.p --[red_field_union]--> Time 35: in function main, expression <loc p> = <loc u> --[red_rvalof]--> Time 36: in function main, expression <loc p> = <ptr x> --[red_assign]--> Time 37: in function main, expression <ptr x> --[step_do_2]--> Time 38: in function main, statement /*skip*/; --[step_skip_seq]--> Time 39: in function main, statement printf(__stringlit_1, (void *) p, (void *) &x); *p = 11; printf(__stringlit_2, x, *p); return 0; --[step_seq]--> Time 40: in function main, statement printf(__stringlit_1, (void *) p, (void *) &x); --[step_do_1]--> Time 41: in function main, expression printf(__stringlit_1, (void *) p, (void *) &x) --[red_var_global]--> Time 42: in function main, expression printf(<loc __stringlit_1>, (void *) p, (void *) &x) --[red_rvalof]--> Time 43: in function main, expression printf(<ptr __stringlit_1>, (void *) p, (void *) &x) --[red_var_local]--> Time 44: in function main, expression printf(<ptr __stringlit_1>, (void *) <loc p>, (void *) &x) --[red_rvalof]--> Time 45: in function main, expression printf(<ptr __stringlit_1>, (void *) <ptr x>, (void *) &x) --[red_cast]--> Time 46: in function main, expression printf(<ptr __stringlit_1>, <ptr x>, (void *) &x) --[red_var_global]--> Time 47: in function main, expression printf(<ptr __stringlit_1>, <ptr x>, (void *) &<loc x>) --[red_addrof]--> Time 48: in function main, expression printf(<ptr __stringlit_1>, <ptr x>, (void *) <ptr x>) --[red_cast]--> Time 49: in function main, expression printf(<ptr __stringlit_1>, <ptr x>, <ptr x>) Addresses: p=<55+0> &x=<55+0> Time 49: observable event: extcall printf(& __stringlit_1, & x, & x) -> 30 --[red_builtin]--> Time 50: in function main, expression 30 --[step_do_2]--> Time 51: in function main, statement /*skip*/; --[step_skip_seq]--> Time 52: in function main, statement *p = 11; printf(__stringlit_2, x, *p); return 0; --[step_seq]--> Time 53: in function main, statement *p = 11; --[step_do_1]--> Time 54: in function main, expression *p = 11 --[red_var_local]--> Time 55: in function main, expression *<loc p> = 11 --[red_rvalof]--> Time 56: in function main, expression *<ptr x> = 11 --[red_deref]--> Time 57: in function main, expression <loc x> = 11 --[red_assign]--> Time 58: in function main, expression 11 --[step_do_2]--> Time 59: in function main, statement /*skip*/; --[step_skip_seq]--> Time 60: in function main, statement printf(__stringlit_2, x, *p); return 0; --[step_seq]--> Time 61: in function main, statement printf(__stringlit_2, x, *p); --[step_do_1]--> Time 62: in function main, expression printf(__stringlit_2, x, *p) --[red_var_global]--> Time 63: in function main, expression printf(<loc __stringlit_2>, x, *p) --[red_rvalof]--> Time 64: in function main, expression printf(<ptr __stringlit_2>, x, *p) --[red_var_global]--> Time 65: in function main, expression printf(<ptr __stringlit_2>, <loc x>, *p) --[red_rvalof]--> Time 66: in function main, expression printf(<ptr __stringlit_2>, 11, *p) --[red_var_local]--> Time 67: in function main, expression printf(<ptr __stringlit_2>, 11, *<loc p>) --[red_rvalof]--> Time 68: in function main, expression printf(<ptr __stringlit_2>, 11, *<ptr x>) --[red_deref]--> Time 69: in function main, expression printf(<ptr __stringlit_2>, 11, <loc x>) --[red_rvalof]--> Time 70: in function main, expression printf(<ptr __stringlit_2>, 11, 11) x=11 *p=11 Time 70: observable event: extcall printf(& __stringlit_2, 11, 11) -> 11 --[red_builtin]--> Time 71: in function main, expression 11 --[step_do_2]--> Time 72: in function main, statement /*skip*/; --[step_skip_seq]--> Time 73: in function main, statement return 0; --[step_return_1]--> Time 74: in function main, expression 0 --[step_return_2]--> Time 75: returning 0 Time 75: program terminated (exit code = 0) In file included from provenance_union_punning_1_global.c:1: In file included from /usr/include/stdio.h:64: In file included from /usr/include/_stdio.h:68: /usr/include/sys/cdefs.h:81:2: warning: "Unsupported compiler detected" [-W#warnings] #warning "Unsupported compiler detected" ^ 1 warning generated.
|