From 7885fac7e904568d58eae4ef34239a3c41241aa8 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Thu, 25 Jul 2019 00:06:47 +0200 Subject: [PATCH] improve error when CTFE does ptr-int-cast; update tests --- src/librustc_mir/const_eval.rs | 13 +++++++++++-- src/librustc_mir/interpret/machine.rs | 6 +----- src/test/ui/consts/const-eval/const_raw_ptr_ops.rs | 4 ++-- .../ui/consts/const-eval/const_raw_ptr_ops.stderr | 14 +++++++++++--- src/test/ui/consts/const-eval/issue-52442.rs | 2 +- src/test/ui/consts/const-eval/issue-52442.stderr | 8 +++----- .../ui/consts/const-eval/match-test-ptr-null.rs | 5 ++--- .../consts/const-eval/match-test-ptr-null.stderr | 12 ++++++------ 8 files changed, 37 insertions(+), 27 deletions(-) diff --git a/src/librustc_mir/const_eval.rs b/src/librustc_mir/const_eval.rs index 813b7f7fa9c3..54cf56258f9f 100644 --- a/src/librustc_mir/const_eval.rs +++ b/src/librustc_mir/const_eval.rs @@ -20,10 +20,10 @@ use rustc_data_structures::fx::FxHashMap; use syntax::source_map::{Span, DUMMY_SP}; use crate::interpret::{self, - PlaceTy, MPlaceTy, OpTy, ImmTy, Immediate, Scalar, + PlaceTy, MPlaceTy, OpTy, ImmTy, Immediate, Scalar, Pointer, RawConst, ConstValue, InterpResult, InterpErrorInfo, GlobalId, InterpCx, StackPopCleanup, - Allocation, AllocId, MemoryKind, + Allocation, AllocId, MemoryKind, Memory, snapshot, RefTracking, intern_const_alloc_recursive, }; @@ -397,6 +397,15 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir, ) } + fn ptr_to_int( + _mem: &Memory<'mir, 'tcx, Self>, + _ptr: Pointer, + ) -> InterpResult<'tcx, u64> { + Err( + ConstEvalError::NeedsRfc("pointer-to-integer cast".to_string()).into(), + ) + } + fn binary_ptr_op( _ecx: &InterpCx<'mir, 'tcx, Self>, _bin_op: mir::BinOp, diff --git a/src/librustc_mir/interpret/machine.rs b/src/librustc_mir/interpret/machine.rs index 4a0cc24cf1e9..a9794982fe50 100644 --- a/src/librustc_mir/interpret/machine.rs +++ b/src/librustc_mir/interpret/machine.rs @@ -233,7 +233,6 @@ pub trait Machine<'mir, 'tcx>: Sized { extra: Self::FrameExtra, ) -> InterpResult<'tcx>; - #[inline(always)] fn int_to_ptr( _mem: &Memory<'mir, 'tcx, Self>, int: u64, @@ -245,11 +244,8 @@ pub trait Machine<'mir, 'tcx>: Sized { }).into()) } - #[inline(always)] fn ptr_to_int( _mem: &Memory<'mir, 'tcx, Self>, _ptr: Pointer, - ) -> InterpResult<'tcx, u64> { - throw_unsup!(ReadPointerAsBytes) - } + ) -> InterpResult<'tcx, u64>; } diff --git a/src/test/ui/consts/const-eval/const_raw_ptr_ops.rs b/src/test/ui/consts/const-eval/const_raw_ptr_ops.rs index 44266682a5c6..9be1374f85d9 100644 --- a/src/test/ui/consts/const-eval/const_raw_ptr_ops.rs +++ b/src/test/ui/consts/const-eval/const_raw_ptr_ops.rs @@ -4,8 +4,8 @@ fn main() {} // unconst and bad, will thus error in miri const X: bool = unsafe { &1 as *const i32 == &2 as *const i32 }; //~ ERROR any use of this -// unconst and fine -const X2: bool = unsafe { 42 as *const i32 == 43 as *const i32 }; +// unconst and bad, will thus error in miri +const X2: bool = unsafe { 42 as *const i32 == 43 as *const i32 }; //~ ERROR any use of this // unconst and fine const Y: usize = unsafe { 42usize as *const i32 as usize + 1 }; // unconst and bad, will thus error in miri diff --git a/src/test/ui/consts/const-eval/const_raw_ptr_ops.stderr b/src/test/ui/consts/const-eval/const_raw_ptr_ops.stderr index a12575b3975b..2cba833a7489 100644 --- a/src/test/ui/consts/const-eval/const_raw_ptr_ops.stderr +++ b/src/test/ui/consts/const-eval/const_raw_ptr_ops.stderr @@ -8,13 +8,21 @@ LL | const X: bool = unsafe { &1 as *const i32 == &2 as *const i32 }; | = note: `#[deny(const_err)]` on by default +error: any use of this value will cause an error + --> $DIR/const_raw_ptr_ops.rs:8:27 + | +LL | const X2: bool = unsafe { 42 as *const i32 == 43 as *const i32 }; + | --------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^--- + | | + | "pointer arithmetic or comparison" needs an rfc before being allowed inside constants + error: any use of this value will cause an error --> $DIR/const_raw_ptr_ops.rs:12:28 | LL | const Y2: usize = unsafe { &1 as *const i32 as usize + 1 }; - | ---------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^--- + | ---------------------------^^^^^^^^^^^^^^^^^^^^^^^^^------- | | - | "pointer arithmetic or comparison" needs an rfc before being allowed inside constants + | "pointer-to-integer cast" needs an rfc before being allowed inside constants error: any use of this value will cause an error --> $DIR/const_raw_ptr_ops.rs:16:26 @@ -32,5 +40,5 @@ LL | const Z3: i32 = unsafe { *(44 as *const i32) }; | | | a memory access tried to interpret some bytes as a pointer -error: aborting due to 4 previous errors +error: aborting due to 5 previous errors diff --git a/src/test/ui/consts/const-eval/issue-52442.rs b/src/test/ui/consts/const-eval/issue-52442.rs index 2989b200b2fc..ea24578c7dd0 100644 --- a/src/test/ui/consts/const-eval/issue-52442.rs +++ b/src/test/ui/consts/const-eval/issue-52442.rs @@ -1,5 +1,5 @@ fn main() { [(); { &loop { break } as *const _ as usize } ]; //~^ ERROR casting pointers to integers in constants is unstable - //~| ERROR it is undefined behavior to use this value + //~| ERROR evaluation of constant value failed } diff --git a/src/test/ui/consts/const-eval/issue-52442.stderr b/src/test/ui/consts/const-eval/issue-52442.stderr index 88c94d917fe0..5bd4979bdb33 100644 --- a/src/test/ui/consts/const-eval/issue-52442.stderr +++ b/src/test/ui/consts/const-eval/issue-52442.stderr @@ -7,13 +7,11 @@ LL | [(); { &loop { break } as *const _ as usize } ]; = note: for more information, see https://github.com/rust-lang/rust/issues/51910 = help: add `#![feature(const_raw_ptr_to_usize_cast)]` to the crate attributes to enable -error[E0080]: it is undefined behavior to use this value - --> $DIR/issue-52442.rs:2:11 +error[E0080]: evaluation of constant value failed + --> $DIR/issue-52442.rs:2:13 | LL | [(); { &loop { break } as *const _ as usize } ]; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a pointer, but expected initialized plain (non-pointer) bytes - | - = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ "pointer-to-integer cast" needs an rfc before being allowed inside constants error: aborting due to 2 previous errors diff --git a/src/test/ui/consts/const-eval/match-test-ptr-null.rs b/src/test/ui/consts/const-eval/match-test-ptr-null.rs index 50757afaf565..9c930221e73e 100644 --- a/src/test/ui/consts/const-eval/match-test-ptr-null.rs +++ b/src/test/ui/consts/const-eval/match-test-ptr-null.rs @@ -1,3 +1,4 @@ + fn main() { // Make sure match uses the usual pointer comparison code path -- i.e., it should complain // that pointer comparison is disallowed, not that parts of a pointer are accessed as raw @@ -5,11 +6,9 @@ fn main() { let _: [u8; 0] = [4; { match &1 as *const i32 as usize { //~^ ERROR casting pointers to integers in constants - //~| NOTE for more information, see //~| ERROR constant contains unimplemented expression type - 0 => 42, //~ ERROR constant contains unimplemented expression type - //~^ NOTE "pointer arithmetic or comparison" needs an rfc before being allowed //~| ERROR evaluation of constant value failed + 0 => 42, //~ ERROR constant contains unimplemented expression type n => n, } }]; diff --git a/src/test/ui/consts/const-eval/match-test-ptr-null.stderr b/src/test/ui/consts/const-eval/match-test-ptr-null.stderr index d8a3bac5ce68..9bb561f31ebb 100644 --- a/src/test/ui/consts/const-eval/match-test-ptr-null.stderr +++ b/src/test/ui/consts/const-eval/match-test-ptr-null.stderr @@ -1,5 +1,5 @@ error[E0658]: casting pointers to integers in constants is unstable - --> $DIR/match-test-ptr-null.rs:6:15 + --> $DIR/match-test-ptr-null.rs:7:15 | LL | match &1 as *const i32 as usize { | ^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -8,22 +8,22 @@ LL | match &1 as *const i32 as usize { = help: add `#![feature(const_raw_ptr_to_usize_cast)]` to the crate attributes to enable error[E0019]: constant contains unimplemented expression type - --> $DIR/match-test-ptr-null.rs:6:15 + --> $DIR/match-test-ptr-null.rs:7:15 | LL | match &1 as *const i32 as usize { | ^^^^^^^^^^^^^^^^^^^^^^^^^ error[E0019]: constant contains unimplemented expression type - --> $DIR/match-test-ptr-null.rs:10:13 + --> $DIR/match-test-ptr-null.rs:11:13 | LL | 0 => 42, | ^ error[E0080]: evaluation of constant value failed - --> $DIR/match-test-ptr-null.rs:10:13 + --> $DIR/match-test-ptr-null.rs:7:15 | -LL | 0 => 42, - | ^ "pointer arithmetic or comparison" needs an rfc before being allowed inside constants +LL | match &1 as *const i32 as usize { + | ^^^^^^^^^^^^^^^^^^^^^^^^^ "pointer-to-integer cast" needs an rfc before being allowed inside constants error: aborting due to 4 previous errors