From c7e3b3f84caf8b34773deba7db37ee2bc5fd23cf Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Sun, 17 Dec 2023 09:34:25 +0100 Subject: [PATCH] do not allow ABI mismatches inside repr(C) types --- library/core/src/primitive_docs.rs | 2 -- .../function_pointers/abi_mismatch_repr_C.rs | 16 ++++++++++++++++ .../abi_mismatch_repr_C.stderr | 17 +++++++++++++++++ 3 files changed, 33 insertions(+), 2 deletions(-) create mode 100644 src/tools/miri/tests/fail/function_pointers/abi_mismatch_repr_C.rs create mode 100644 src/tools/miri/tests/fail/function_pointers/abi_mismatch_repr_C.stderr diff --git a/library/core/src/primitive_docs.rs b/library/core/src/primitive_docs.rs index 588f9b865b065..99208fba67059 100644 --- a/library/core/src/primitive_docs.rs +++ b/library/core/src/primitive_docs.rs @@ -1575,8 +1575,6 @@ mod prim_ref {} /// Furthermore, ABI compatibility satisfies the following general properties: /// /// - Every type is ABI-compatible with itself. -/// - If `T1` and `T2` are ABI-compatible, then two `repr(C)` types that only differ because one -/// field type was changed from `T1` to `T2` are ABI-compatible. /// - If `T1` and `T2` are ABI-compatible and `T2` and `T3` are ABI-compatible, then so are `T1` and /// `T3` (i.e., ABI-compatibility is transitive). /// - If `T1` and `T2` are ABI-compatible, then so are `T2` and `T1` (i.e., ABI-compatibility is diff --git a/src/tools/miri/tests/fail/function_pointers/abi_mismatch_repr_C.rs b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_repr_C.rs new file mode 100644 index 0000000000000..2cf4e04477778 --- /dev/null +++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_repr_C.rs @@ -0,0 +1,16 @@ +use std::num::*; + +#[repr(C)] +struct S1(NonZeroI32); + +#[repr(C)] +struct S2(i32); + +fn callee(_s: S2) {} + +fn main() { + let fnptr: fn(S2) = callee; + let fnptr: fn(S1) = unsafe { std::mem::transmute(fnptr) }; + fnptr(S1(NonZeroI32::new(1).unwrap())); + //~^ ERROR: calling a function with argument of type S2 passing data of type S1 +} diff --git a/src/tools/miri/tests/fail/function_pointers/abi_mismatch_repr_C.stderr b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_repr_C.stderr new file mode 100644 index 0000000000000..6d42bea9da998 --- /dev/null +++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_repr_C.stderr @@ -0,0 +1,17 @@ +error: Undefined Behavior: calling a function with argument of type S2 passing data of type S1 + --> $DIR/abi_mismatch_repr_C.rs:LL:CC + | +LL | fnptr(S1(NonZeroI32::new(1).unwrap())); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ calling a function with argument of type S2 passing data of type S1 + | + = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior + = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information + = help: this means these two types are not *guaranteed* to be ABI-compatible across all targets + = help: if you think this code should be accepted anyway, please report an issue + = note: BACKTRACE: + = note: inside `main` at $DIR/abi_mismatch_repr_C.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 +