From 94ca0b392df7c0f551c136394bf3456bee041357 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Sat, 13 Nov 2021 20:55:33 -0500 Subject: [PATCH] fix ICE on Miri/CTFE copy of half a pointer --- .../rustc_const_eval/src/interpret/memory.rs | 13 +++++----- src/test/ui/consts/issue-miri-1910.rs | 12 +++++++++ src/test/ui/consts/issue-miri-1910.stderr | 26 +++++++++++++++++++ 3 files changed, 44 insertions(+), 7 deletions(-) create mode 100644 src/test/ui/consts/issue-miri-1910.rs create mode 100644 src/test/ui/consts/issue-miri-1910.stderr diff --git a/compiler/rustc_const_eval/src/interpret/memory.rs b/compiler/rustc_const_eval/src/interpret/memory.rs index b8b6ff93753f0..4aa3c83cc0243 100644 --- a/compiler/rustc_const_eval/src/interpret/memory.rs +++ b/compiler/rustc_const_eval/src/interpret/memory.rs @@ -1057,20 +1057,19 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> { Some(dest_ptr) => dest_ptr, }; + // This checks relocation edges on the src, which needs to happen before + // `prepare_relocation_copy`. + let src_bytes = src_alloc + .get_bytes_with_uninit_and_ptr(&tcx, src_range) + .map_err(|e| e.to_interp_error(src_alloc_id))? + .as_ptr(); // raw ptr, so we can also get a ptr to the destination allocation // first copy the relocations to a temporary buffer, because // `get_bytes_mut` will clear the relocations, which is correct, // since we don't want to keep any relocations at the target. - // (`get_bytes_with_uninit_and_ptr` below checks that there are no - // relocations overlapping the edges; those would not be handled correctly). let relocations = src_alloc.prepare_relocation_copy(self, src_range, dest_offset, num_copies); // Prepare a copy of the initialization mask. let compressed = src_alloc.compress_uninit_range(src_range); - // This checks relocation edges on the src. - let src_bytes = src_alloc - .get_bytes_with_uninit_and_ptr(&tcx, src_range) - .map_err(|e| e.to_interp_error(src_alloc_id))? - .as_ptr(); // raw ptr, so we can also get a ptr to the destination allocation // Destination alloc preparations and access hooks. let (dest_alloc, extra) = self.get_raw_mut(dest_alloc_id)?; diff --git a/src/test/ui/consts/issue-miri-1910.rs b/src/test/ui/consts/issue-miri-1910.rs new file mode 100644 index 0000000000000..20efa145dbe1e --- /dev/null +++ b/src/test/ui/consts/issue-miri-1910.rs @@ -0,0 +1,12 @@ +// error-pattern unable to turn pointer into raw bytes +#![feature(const_ptr_read)] +#![feature(const_ptr_offset)] + +const C: () = unsafe { + let foo = Some(&42 as *const i32); + let one_and_a_half_pointers = std::mem::size_of::<*const i32>()/2*3; + (&foo as *const _ as *const u8).add(one_and_a_half_pointers).read(); +}; + +fn main() { +} diff --git a/src/test/ui/consts/issue-miri-1910.stderr b/src/test/ui/consts/issue-miri-1910.stderr new file mode 100644 index 0000000000000..e2f4ef635887c --- /dev/null +++ b/src/test/ui/consts/issue-miri-1910.stderr @@ -0,0 +1,26 @@ +error: any use of this value will cause an error + --> $SRC_DIR/core/src/ptr/mod.rs:LL:COL + | +LL | copy_nonoverlapping(src, tmp.as_mut_ptr(), 1); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | | + | unable to turn pointer into raw bytes + | inside `std::ptr::read::` at $SRC_DIR/core/src/ptr/mod.rs:LL:COL + | inside `ptr::const_ptr::::read` at $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL + | inside `C` at $DIR/issue-miri-1910.rs:8:5 + | + ::: $DIR/issue-miri-1910.rs:5:1 + | +LL | / const C: () = unsafe { +LL | | let foo = Some(&42 as *const i32); +LL | | let one_and_a_half_pointers = std::mem::size_of::<*const i32>()/2*3; +LL | | (&foo as *const _ as *const u8).add(one_and_a_half_pointers).read(); +LL | | }; + | |__- + | + = note: `#[deny(const_err)]` on by default + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #71800 + +error: aborting due to previous error +