src/test/ui/extern/extern-static-size-overflow.rs

   1 #[repr(C)]
   2 struct ReallyBig {
   3     _a: [u8; usize::MAX],
   4 }
   5
   6 // The limit for "too big for the current architecture" is dependent on the target pointer size
   7 // however it's artificially limited on 64 bits
   8 // logic copied from rustc_target::abi::TargetDataLayout::obj_size_bound()
   9 const fn max_size() -> usize {
  10     #[cfg(target_pointer_width = "16")]
  11     {
  12         1 << 15
  13     }
  14
  15     #[cfg(target_pointer_width = "32")]
  16     {
  17         1 << 31
  18     }
  19
  20     #[cfg(target_pointer_width = "64")]
  21     {
  22         1 << 47
  23     }
  24
  25     #[cfg(not(any(
  26         target_pointer_width = "16",
  27         target_pointer_width = "32",
  28         target_pointer_width = "64"
  29     )))]
  30     {
  31         isize::MAX as usize
  32     }
  33 }
  34
  35 extern "C" {
  36     static FOO: [u8; 1];
  37     static BAR: [u8; max_size() - 1];
  38     static BAZ: [u8; max_size()]; //~ ERROR extern static is too large
  39     static UWU: [usize; usize::MAX]; //~ ERROR extern static is too large
  40     static A: ReallyBig; //~ ERROR extern static is too large
  41 }
  42
  43 fn main() {}