From f813ccd7840e7aee205d39be06166e5cbdaf54e3 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 11 Dec 2023 13:49:26 +0100 Subject: [PATCH] also add a Miri test --- .../tests/fail/extern-type-field-offset.rs | 29 +++++++++++++++++++ .../fail/extern-type-field-offset.stderr | 14 +++++++++ 2 files changed, 43 insertions(+) create mode 100644 src/tools/miri/tests/fail/extern-type-field-offset.rs create mode 100644 src/tools/miri/tests/fail/extern-type-field-offset.stderr diff --git a/src/tools/miri/tests/fail/extern-type-field-offset.rs b/src/tools/miri/tests/fail/extern-type-field-offset.rs new file mode 100644 index 00000000000..139405fc374 --- /dev/null +++ b/src/tools/miri/tests/fail/extern-type-field-offset.rs @@ -0,0 +1,29 @@ +#![feature(extern_types)] + +extern "C" { + type Opaque; +} + +struct Newtype(Opaque); + +struct S { + i: i32, + j: i32, + a: Newtype, +} + +fn main() { + let buf = [0i32; 4]; + + let x: &Newtype = unsafe { &*(&buf as *const _ as *const Newtype) }; + // Projecting to the newtype works, because it is always at offset 0. + let _field = &x.0; + + let x: &S = unsafe { &*(&buf as *const _ as *const S) }; + // Accessing sized fields is perfectly fine, even at non-zero offsets. + let _field = &x.i; + let _field = &x.j; + // This needs to compute the field offset, but we don't know the type's alignment, + // so this panics. + let _field = &x.a; //~ERROR: does not have a known offset +} diff --git a/src/tools/miri/tests/fail/extern-type-field-offset.stderr b/src/tools/miri/tests/fail/extern-type-field-offset.stderr new file mode 100644 index 00000000000..cbbf1b38361 --- /dev/null +++ b/src/tools/miri/tests/fail/extern-type-field-offset.stderr @@ -0,0 +1,14 @@ +error: unsupported operation: `extern type` does not have a known offset + --> $DIR/extern-type-field-offset.rs:LL:CC + | +LL | let _field = &x.a; + | ^^^^ `extern type` does not have a known offset + | + = help: this is likely not a bug in the program; it indicates that the program performed an operation that the interpreter does not support + = note: BACKTRACE: + = note: inside `main` at $DIR/extern-type-field-offset.rs:LL:CC + +note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace + +error: aborting due to 1 previous error +