src/test/ui/consts/miri_unleashed/const_refers_to_static_cross_crate.rs

   1 // compile-flags: -Zunleash-the-miri-inside-of-you
   2 // aux-build:static_cross_crate.rs
   3 #![allow(const_err)]
   4
   5 #![feature(exclusive_range_pattern, half_open_range_patterns)]
   6
   7 extern crate static_cross_crate;
   8
   9 // Sneaky: reference to a mutable static.
  10 // Allowing this would be a disaster for pattern matching, we could violate exhaustiveness checking!
  11 const SLICE_MUT: &[u8; 1] = { //~ ERROR undefined behavior to use this value
  12 //~| NOTE encountered a reference pointing to a static variable
  13 //~| NOTE
  14     unsafe { &static_cross_crate::ZERO }
  15 };
  16
  17 const U8_MUT: &u8 = { //~ ERROR undefined behavior to use this value
  18 //~| NOTE encountered a reference pointing to a static variable
  19 //~| NOTE
  20     unsafe { &static_cross_crate::ZERO[0] }
  21 };
  22
  23 // Also test indirection that reads from other static. This causes a const_err.
  24 #[warn(const_err)] //~ NOTE
  25 const U8_MUT2: &u8 = { //~ NOTE
  26     unsafe { &(*static_cross_crate::ZERO_REF)[0] }
  27     //~^ WARN [const_err]
  28     //~| NOTE constant accesses static
  29     //~| WARN this was previously accepted by the compiler but is being phased out
  30     //~| NOTE
  31 };
  32 #[warn(const_err)] //~ NOTE
  33 const U8_MUT3: &u8 = { //~ NOTE
  34     unsafe { match static_cross_crate::OPT_ZERO { Some(ref u) => u, None => panic!() } }
  35     //~^ WARN [const_err]
  36     //~| NOTE constant accesses static
  37     //~| NOTE in this expansion of panic!
  38     //~| WARN this was previously accepted by the compiler but is being phased out
  39     //~| NOTE
  40 };
  41
  42 pub fn test(x: &[u8; 1]) -> bool {
  43     match x {
  44         SLICE_MUT => true,
  45         //~^ ERROR could not evaluate constant pattern
  46         //~| ERROR could not evaluate constant pattern
  47         &[1..] => false,
  48     }
  49 }
  50
  51 pub fn test2(x: &u8) -> bool {
  52     match x {
  53         U8_MUT => true,
  54         //~^ ERROR could not evaluate constant pattern
  55         //~| ERROR could not evaluate constant pattern
  56         &(1..) => false,
  57     }
  58 }
  59
  60 // We need to use these *in a pattern* to trigger the failure... likely because
  61 // the errors above otherwise stop compilation too early?
  62 pub fn test3(x: &u8) -> bool {
  63     match x {
  64         U8_MUT2 => true,
  65         //~^ ERROR could not evaluate constant pattern
  66         //~| ERROR could not evaluate constant pattern
  67         &(1..) => false,
  68     }
  69 }
  70 pub fn test4(x: &u8) -> bool {
  71     match x {
  72         U8_MUT3 => true,
  73         //~^ ERROR could not evaluate constant pattern
  74         //~| ERROR could not evaluate constant pattern
  75         &(1..) => false,
  76     }
  77 }
  78
  79 fn main() {
  80     unsafe {
  81         static_cross_crate::ZERO[0] = 1;
  82     }
  83     // Now the pattern is not exhaustive any more!
  84     test(&[0]);
  85     test2(&0);
  86 }