Rebase fallout

Author: oli-obk

src/librustc_lint/builtin.rs

@@ -1547,49 +1547,6 @@ impl LintPass for UnusedBrokenConst {
         lint_array!()
     }
 }
-
-fn validate_const<'a, 'tcx>(
-    tcx: ty::TyCtxt<'a, 'tcx, 'tcx>,
-    constant: &ty::Const<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
-    gid: ::rustc::mir::interpret::GlobalId<'tcx>,
-    what: &str,
-) {
-    let ecx = ::rustc_mir::const_eval::mk_eval_cx(tcx, gid.instance, param_env).unwrap();
-    let result = (|| {
-        let op = ecx.const_to_op(constant)?;
-        let mut ref_tracking = ::rustc_mir::interpret::RefTracking::new(op);
-        while let Some((op, mut path)) = ref_tracking.todo.pop() {
-            ecx.validate_operand(
-                op,
-                &mut path,
-                Some(&mut ref_tracking),
-                /* const_mode */ true,
-            )?;
-        }
-        Ok(())
-    })();
-    if let Err(err) = result {
-        let (trace, span) = ecx.generate_stacktrace(None);
-        let err = ::rustc::mir::interpret::ConstEvalErr {
-            error: err,
-            stacktrace: trace,
-            span,
-        };
-        let err = err.struct_error(
-            tcx.at(span),
-            &format!("this {} likely exhibits undefined behavior", what),
-        );
-        if let Some(mut err) = err {
-            err.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",
-            );
-            err.emit();
-        }
-    }
-}
-
 fn check_const(cx: &LateContext, body_id: hir::BodyId) {
     let def_id = cx.tcx.hir.body_owner_def_id(body_id);
     let is_static = cx.tcx.is_static(def_id).is_some();

src/librustc_mir/const_eval.rs

@@ -24,7 +24,6 @@ use rustc::ty::{self, Ty, TyCtxt, Instance, query::TyCtxtAt};
 use rustc::ty::layout::{self, Size, LayoutOf, TyLayout};
 use rustc::ty::subst::Subst;
 use rustc::traits::Reveal;
-use rustc::util::nodemap::FxHashSet;
 use rustc_data_structures::indexed_vec::IndexVec;
 use rustc_data_structures::fx::FxHashMap;
 use rustc::util::common::ErrorReported;
@@ -36,7 +35,7 @@ use interpret::{self,
     PlaceTy, MemPlace, OpTy, Operand, Value, Pointer, Scalar, ConstValue,
     EvalResult, EvalError, EvalErrorKind, GlobalId, EvalContext, StackPopCleanup,
     Allocation, AllocId, MemoryKind,
-    snapshot,
+    snapshot, RefTracking,
 };
 
 /// Number of steps until the detector even starts doing anything.
@@ -542,15 +541,13 @@ fn validate_const<'a, 'tcx>(
     let ecx = mk_eval_cx(tcx, cid.instance, key.param_env).unwrap();
     let val = (|| {
         let op = ecx.const_to_op(constant)?;
-        let mut todo = vec![(op, Vec::new())];
-        let mut seen = FxHashSet();
-        seen.insert(op);
-        while let Some((op, mut path)) = todo.pop() {
+        let mut ref_tracking = RefTracking::new(op);
+        while let Some((op, mut path)) = ref_tracking.todo.pop() {
             ecx.validate_operand(
                 op,
                 &mut path,
-                &mut seen,
-                &mut todo,
+                Some(&mut ref_tracking),
+                /* const_mode */ true,
             )?;
         }
         Ok(constant)

src/test/compile-fail/const-fn-error.rs

@@ -16,7 +16,7 @@ const fn f(x: usize) -> usize {
     let mut sum = 0;
     //~^ let bindings in constant functions are unstable
     //~| statements in constant functions are unstable
-    for i in 0..x { //~ ERROR E0080
+    for i in 0..x {
         //~^ ERROR E0015
         //~| ERROR E0019
         sum += i;

src/test/compile-fail/issue-52443.rs

@@ -14,5 +14,4 @@ fn main() {
     [(); {while true {break}; 0}]; //~ ERROR constant contains unimplemented expression type
     [(); { for _ in 0usize.. {}; 0}]; //~ ERROR calls in constants are limited to constant functions
     //~^ ERROR constant contains unimplemented expression type
-    //~| ERROR evaluation of constant value failed
 }

src/test/ui/consts/const-call.stderr

@@ -4,12 +4,6 @@ error[E0015]: calls in constants are limited to constant functions, tuple struct
 LL |     let _ = [0; f(2)];
    |                 ^^^^
 
-error[E0080]: evaluation of constant value failed
-  --> $DIR/const-call.rs:16:17
-   |
-LL |     let _ = [0; f(2)];
-   |                 ^^^^ calling non-const fn `f`
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0015`.

src/test/ui/consts/const-eval/conditional_array_execution.nll.stderr

@@ -1,5 +1,5 @@
 warning: any use of this value will cause an error
-  --> $DIR/issue-43197.rs:20:5
+  --> $DIR/issue-43197.rs:18:5
    |
 LL |     const X: u32 = 0-1;
    |     ^^^^^^^^^^^^^^^---^
@@ -13,21 +13,21 @@ LL | #![warn(const_err)]
    |         ^^^^^^^^^
 
 warning: any use of this value will cause an error
-  --> $DIR/issue-43197.rs:22:5
+  --> $DIR/issue-43197.rs:20:5
    |
 LL |     const Y: u32 = foo(0-1);
    |     ^^^^^^^^^^^^^^^^^^^---^^
    |                        |
    |                        attempt to subtract with overflow
 
 error[E0080]: evaluation of constant expression failed
-  --> $DIR/issue-43197.rs:24:26
+  --> $DIR/issue-43197.rs:22:26
    |
 LL |     println!("{} {}", X, Y);
    |                          ^ referenced constant has errors
 
 error[E0080]: evaluation of constant expression failed
-  --> $DIR/issue-43197.rs:24:23
+  --> $DIR/issue-43197.rs:22:23
    |
 LL |     println!("{} {}", X, Y);
    |                       ^ referenced constant has errors

src/test/ui/consts/const-eval/issue-43197.nll.stderr

@@ -8,7 +8,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/issue-52442.rs:12:11
    |
 LL |     [();  { &loop { break } as *const _ as usize } ]; //~ ERROR unimplemented expression type
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a pointer, but expected the type usize
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a pointer, but expected initialized plain bits
    |
    = 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
 

src/test/ui/consts/const-eval/issue-43197.stderr

@@ -0,0 +1,14 @@
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/promoted_const_fn_fail_deny_const_err.rs:31:27
+   |
+LL |     let x: &'static u8 = &(bar() + 1);
+   |            -----------    ^^^^^^^^^^^ creates a temporary which is freed while still in use
+   |            |
+   |            type annotation requires that borrow lasts for `'static`
+...
+LL | }
+   | - temporary value is freed at the end of this statement
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0716`.

src/test/ui/consts/const-eval/issue-44578.nll.stderr

@@ -1,19 +1,14 @@
-error: reaching this expression at runtime will panic or abort
-  --> $DIR/promoted_const_fn_fail_deny_const_err.rs:31:26
+error[E0597]: borrowed value does not live long enough
+  --> $DIR/promoted_const_fn_fail_deny_const_err.rs:31:27
    |
-LL |         Bar { a: &42 }.b as u8
-   |         ---------------------- a raw memory access tried to access part of a pointer value as raw bytes
-...
 LL |     let x: &'static u8 = &(bar() + 1);
-   |                          ^^-----^^^^^
-   |                            |
-   |                            inside call to `bar`
-   |
-note: lint level defined here
-  --> $DIR/promoted_const_fn_fail_deny_const_err.rs:13:9
+   |                           ^^^^^^^^^^^ temporary value does not live long enough
+...
+LL | }
+   | - temporary value only lives until here
    |
-LL | #![deny(const_err)]
-   |         ^^^^^^^^^
+   = note: borrowed value must be valid for the static lifetime...
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0597`.

src/test/ui/consts/const-eval/issue-52442.stderr

@@ -2,7 +2,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ref_to_int_match.rs:33:1
    |
 LL | const BAR: Int = unsafe { Foo { r: &42 }.f }; //~ ERROR it is undefined behavior to use this value
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a pointer, but expected the type u64
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a pointer, but expected initialized plain bits
    |
    = 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
 

src/test/ui/consts/const-eval/issue-52443.stderr

@@ -13,6 +13,6 @@
 use std::mem;
 
 static FOO: bool = unsafe { mem::transmute(3u8) };
-//~^ ERROR this static likely exhibits undefined behavior
+//~^ ERROR it is undefined behavior to use this value
 
 fn main() {}

src/test/ui/consts/const-eval/promoted_const_fn_fail_deny_const_err.nll.stderr

@@ -15,11 +15,11 @@ use std::ptr::NonNull;
 use std::num::{NonZeroU8, NonZeroUsize};
 
 const NULL_PTR: NonNull<u8> = unsafe { mem::transmute(0usize) };
-//~^ ERROR this constant likely exhibits undefined behavior
+//~^ ERROR it is undefined behavior to use this value
 
 const NULL_U8: NonZeroU8 = unsafe { mem::transmute(0u8) };
-//~^ ERROR this constant likely exhibits undefined behavior
+//~^ ERROR it is undefined behavior to use this value
 const NULL_USIZE: NonZeroUsize = unsafe { mem::transmute(0usize) };
-//~^ ERROR this constant likely exhibits undefined behavior
+//~^ ERROR it is undefined behavior to use this value
 
 fn main() {}

src/test/ui/consts/const-eval/promoted_const_fn_fail_deny_const_err.stderr

@@ -1,20 +1,20 @@
-error[E0080]: this constant likely exhibits undefined behavior
+error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-nonnull.rs:17:1
    |
 LL | const NULL_PTR: NonNull<u8> = unsafe { mem::transmute(0usize) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 0, but expected something greater or equal to 1
    |
    = 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
 
-error[E0080]: this constant likely exhibits undefined behavior
+error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-nonnull.rs:20:1
    |
 LL | const NULL_U8: NonZeroU8 = unsafe { mem::transmute(0u8) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 0, but expected something greater or equal to 1
    |
    = 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
 
-error[E0080]: this constant likely exhibits undefined behavior
+error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-nonnull.rs:22:1
    |
 LL | const NULL_USIZE: NonZeroUsize = unsafe { mem::transmute(0usize) };