Auto merge of #149375 - oli-obk:const_typeck, r=fee1-dead

Perform many const checks in typeck

Some smaller diagnostic changes, the biggest ones avoided by https://github.com/rust-lang/rust/pull/148641

We should be able to move various checks in mir const checking to using `span_bug!` instead of reporting an error, just like mir typeck does as a sanity check. I would like to start doing so separately though, as this PR is a big enough (in what effects it causes, pun intended).

r? @fee1-dead

compiler/rustc_hir_typeck/src/callee.rs

@@ -905,14 +905,6 @@ pub(super) fn enforce_context_effects(
         callee_did: DefId,
         callee_args: GenericArgsRef<'tcx>,
     ) {
-        // FIXME(const_trait_impl): We should be enforcing these effects unconditionally.
-        // This can be done as soon as we convert the standard library back to
-        // using const traits, since if we were to enforce these conditions now,
-        // we'd fail on basically every builtin trait call (i.e. `1 + 2`).
-        if !self.tcx.features().const_trait_impl() {
-            return;
-        }
-
         // If we have `rustc_do_not_const_check`, do not check `[const]` bounds.
         if self.has_rustc_attrs
             && find_attr!(self.tcx.get_all_attrs(self.body_id), AttributeKind::RustcDoNotConstCheck)

tests/crashes/137187.rs

@@ -1,10 +1,13 @@
 //@ known-bug: #137187
-use std::ops::Add;
+#![feature(const_trait_impl, const_ops)]
 
+use std::ops::Add;
 const trait A where
-    *const Self: Add,
+    *const Self: const Add,
 {
     fn b(c: *const Self) -> <*const Self as Add>::Output {
         c + c
     }
 }
+
+fn main() {}

tests/ui/coercion/coerce-loop-issue-122561.rs

@@ -42,6 +42,8 @@ fn for_never_type() -> ! {
 //    that it's readable
 fn for_in_arg(a: &[(); for x in 0..2 {}]) -> bool {
     //~^ ERROR mismatched types
+    //~| ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
+    //~| ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
     true
 }
 
@@ -86,6 +88,8 @@ fn loop_() -> bool {
 const C: i32 = {
     for i in 0.. {
     //~^ ERROR mismatched types
+    //~| ERROR `std::ops::RangeFrom<{integer}>: const Iterator` is not satisfied
+    //~| ERROR `std::ops::RangeFrom<{integer}>: const Iterator` is not satisfied
     }
 };
 
@@ -93,6 +97,8 @@ fn main() {
     let _ = [10; {
         for i in 0..5 {
         //~^ ERROR mismatched types
+        //~| ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
+        //~| ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
         }
     }];
 
@@ -105,4 +111,6 @@ fn main() {
 
     let _ = |a: &[(); for x in 0..2 {}]| {};
     //~^ ERROR mismatched types
+    //~| ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
+    //~| ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
 }

tests/ui/coercion/coerce-loop-issue-122561.stderr

@@ -1,5 +1,5 @@
 warning: denote infinite loops with `loop { ... }`
-  --> $DIR/coerce-loop-issue-122561.rs:49:5
+  --> $DIR/coerce-loop-issue-122561.rs:51:5
    |
 LL |     while true {
    |     ^^^^^^^^^^ help: use `loop`
@@ -7,11 +7,30 @@ LL |     while true {
    = note: `#[warn(while_true)]` on by default
 
 warning: denote infinite loops with `loop { ... }`
-  --> $DIR/coerce-loop-issue-122561.rs:73:5
+  --> $DIR/coerce-loop-issue-122561.rs:75:5
    |
 LL |     while true {
    |     ^^^^^^^^^^ help: use `loop`
 
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/coerce-loop-issue-122561.rs:43:33
+   |
+LL | fn for_in_arg(a: &[(); for x in 0..2 {}]) -> bool {
+   |                                 ^^^^ required by a bound introduced by this call
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<{integer}>` to implement `const IntoIterator`
+
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/coerce-loop-issue-122561.rs:43:33
+   |
+LL | fn for_in_arg(a: &[(); for x in 0..2 {}]) -> bool {
+   |                                 ^^^^
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+
 error[E0308]: mismatched types
   --> $DIR/coerce-loop-issue-122561.rs:43:24
    |
@@ -112,7 +131,7 @@ LL | fn for_single_line() -> bool { for i in 0.. { return false; } /* `bool` val
    |                                                               ++++++++++++++++++
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-loop-issue-122561.rs:49:5
+  --> $DIR/coerce-loop-issue-122561.rs:51:5
    |
 LL |   fn while_inifinite() -> bool {
    |                           ---- expected `bool` because of return type
@@ -131,7 +150,7 @@ LL +     /* `bool` value */
    |
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-loop-issue-122561.rs:58:5
+  --> $DIR/coerce-loop-issue-122561.rs:60:5
    |
 LL |   fn while_finite() -> bool {
    |                        ---- expected `bool` because of return type
@@ -151,7 +170,7 @@ LL +     /* `bool` value */
    |
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-loop-issue-122561.rs:66:5
+  --> $DIR/coerce-loop-issue-122561.rs:68:5
    |
 LL |   fn while_zero_times() -> bool {
    |                            ---- expected `bool` because of return type
@@ -169,7 +188,7 @@ LL +     /* `bool` value */
    |
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-loop-issue-122561.rs:73:5
+  --> $DIR/coerce-loop-issue-122561.rs:75:5
    |
 LL |   fn while_never_type() -> ! {
    |                            - expected `!` because of return type
@@ -187,11 +206,30 @@ LL ~     }
 LL +     /* `loop {}` or `panic!("...")` */
    |
 
+error[E0277]: the trait bound `std::ops::RangeFrom<{integer}>: const Iterator` is not satisfied
+  --> $DIR/coerce-loop-issue-122561.rs:89:14
+   |
+LL |     for i in 0.. {
+   |              ^^^ required by a bound introduced by this call
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::RangeFrom<{integer}>` to implement `const IntoIterator`
+
+error[E0277]: the trait bound `std::ops::RangeFrom<{integer}>: const Iterator` is not satisfied
+  --> $DIR/coerce-loop-issue-122561.rs:89:14
+   |
+LL |     for i in 0.. {
+   |              ^^^
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+
 error[E0308]: mismatched types
-  --> $DIR/coerce-loop-issue-122561.rs:87:5
+  --> $DIR/coerce-loop-issue-122561.rs:89:5
    |
 LL | /     for i in 0.. {
-LL | |
+...  |
 LL | |     }
    | |_____^ expected `i32`, found `()`
    |
@@ -202,11 +240,30 @@ LL ~     }
 LL +     /* `i32` value */
    |
 
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/coerce-loop-issue-122561.rs:98:18
+   |
+LL |         for i in 0..5 {
+   |                  ^^^^ required by a bound introduced by this call
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<{integer}>` to implement `const IntoIterator`
+
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/coerce-loop-issue-122561.rs:98:18
+   |
+LL |         for i in 0..5 {
+   |                  ^^^^
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+
 error[E0308]: mismatched types
-  --> $DIR/coerce-loop-issue-122561.rs:94:9
+  --> $DIR/coerce-loop-issue-122561.rs:98:9
    |
 LL | /         for i in 0..5 {
-LL | |
+...  |
 LL | |         }
    | |_________^ expected `usize`, found `()`
    |
@@ -218,7 +275,7 @@ LL +         /* `usize` value */
    |
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-loop-issue-122561.rs:100:9
+  --> $DIR/coerce-loop-issue-122561.rs:106:9
    |
 LL | /         while false {
 LL | |
@@ -232,8 +289,27 @@ LL ~         }
 LL +         /* `usize` value */
    |
 
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/coerce-loop-issue-122561.rs:112:32
+   |
+LL |     let _ = |a: &[(); for x in 0..2 {}]| {};
+   |                                ^^^^ required by a bound introduced by this call
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<{integer}>` to implement `const IntoIterator`
+
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/coerce-loop-issue-122561.rs:112:32
+   |
+LL |     let _ = |a: &[(); for x in 0..2 {}]| {};
+   |                                ^^^^
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+
 error[E0308]: mismatched types
-  --> $DIR/coerce-loop-issue-122561.rs:106:23
+  --> $DIR/coerce-loop-issue-122561.rs:112:23
    |
 LL |     let _ = |a: &[(); for x in 0..2 {}]| {};
    |                       ^^^^^^^^^^^^^^^^ expected `usize`, found `()`
@@ -244,6 +320,7 @@ help: consider returning a value here
 LL |     let _ = |a: &[(); for x in 0..2 {} /* `usize` value */]| {};
    |                                        +++++++++++++++++++
 
-error: aborting due to 14 previous errors; 2 warnings emitted
+error: aborting due to 22 previous errors; 2 warnings emitted
 
-For more information about this error, try `rustc --explain E0308`.
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.

tests/ui/consts/const-eval/const_raw_ptr_ops.stable.stderr

@@ -1,18 +1,23 @@
-error: pointers cannot be reliably compared during const eval
+error[E0277]: pointers cannot be reliably compared during const eval
   --> $DIR/const_raw_ptr_ops.rs:7:26
    |
 LL | const X: bool = unsafe { &1 as *const i32 == &2 as *const i32 };
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+note: trait `PartialEq` is implemented but not `const`
+  --> $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL
    = note: see issue #53020 <https://github.com/rust-lang/rust/issues/53020> for more information
 
-error: pointers cannot be reliably compared during const eval
+error[E0277]: pointers cannot be reliably compared during const eval
   --> $DIR/const_raw_ptr_ops.rs:9:27
    |
 LL | const X2: bool = unsafe { 42 as *const i32 == 43 as *const i32 };
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+note: trait `PartialEq` is implemented but not `const`
+  --> $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL
    = note: see issue #53020 <https://github.com/rust-lang/rust/issues/53020> for more information
 
 error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0277`.

tests/ui/consts/const-fn-error.rs

@@ -3,8 +3,8 @@
 const fn f(x: usize) -> usize {
     let mut sum = 0;
     for i in 0..x {
-        //~^ ERROR cannot use `for`
-        //~| ERROR cannot use `for`
+        //~^ ERROR `std::ops::Range<usize>: [const] Iterator` is not satisfied
+        //~| ERROR `std::ops::Range<usize>: [const] Iterator` is not satisfied
         sum += i;
     }
     sum

tests/ui/consts/const-fn-error.stderr

@@ -1,20 +1,22 @@
-error[E0015]: cannot use `for` loop on `std::ops::Range<usize>` in constant functions
+error[E0277]: the trait bound `std::ops::Range<usize>: [const] Iterator` is not satisfied
   --> $DIR/const-fn-error.rs:5:14
    |
 LL |     for i in 0..x {
-   |              ^^^^
+   |              ^^^^ required by a bound introduced by this call
    |
-   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<usize>` to implement `[const] IntoIterator`
 
-error[E0015]: cannot use `for` loop on `std::ops::Range<usize>` in constant functions
+error[E0277]: the trait bound `std::ops::Range<usize>: [const] Iterator` is not satisfied
   --> $DIR/const-fn-error.rs:5:14
    |
 LL |     for i in 0..x {
    |              ^^^^
    |
-   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0015`.
+For more information about this error, try `rustc --explain E0277`.

tests/ui/consts/const-for-feature-gate.rs

@@ -2,8 +2,8 @@
 
 const _: () = {
     for _ in 0..5 {}
-    //~^ ERROR cannot use `for`
-    //~| ERROR cannot use `for`
+    //~^ ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
+    //~| ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
 };
 
 fn main() {}

tests/ui/consts/const-for-feature-gate.stderr

@@ -1,20 +1,22 @@
-error[E0015]: cannot use `for` loop on `std::ops::Range<i32>` in constants
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
   --> $DIR/const-for-feature-gate.rs:4:14
    |
 LL |     for _ in 0..5 {}
-   |              ^^^^
+   |              ^^^^ required by a bound introduced by this call
    |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<{integer}>` to implement `const IntoIterator`
 
-error[E0015]: cannot use `for` loop on `std::ops::Range<i32>` in constants
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
   --> $DIR/const-for-feature-gate.rs:4:14
    |
 LL |     for _ in 0..5 {}
    |              ^^^^
    |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0015`.
+For more information about this error, try `rustc --explain E0277`.

tests/ui/consts/const-for.rs

@@ -2,8 +2,8 @@
 
 const _: () = {
     for _ in 0..5 {}
-    //~^ ERROR cannot use `for`
-    //~| ERROR cannot use `for`
+    //~^ ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
+    //~| ERROR `std::ops::Range<{integer}>: const Iterator` is not satisfied
 };
 
 fn main() {}

tests/ui/consts/const-for.stderr

@@ -1,20 +1,22 @@
-error[E0015]: cannot use `for` loop on `std::ops::Range<i32>` in constants
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
   --> $DIR/const-for.rs:4:14
    |
 LL |     for _ in 0..5 {}
-   |              ^^^^
+   |              ^^^^ required by a bound introduced by this call
    |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<{integer}>` to implement `const IntoIterator`
 
-error[E0015]: cannot use `for` loop on `std::ops::Range<i32>` in constants
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
   --> $DIR/const-for.rs:4:14
    |
 LL |     for _ in 0..5 {}
    |              ^^^^
    |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0015`.
+For more information about this error, try `rustc --explain E0277`.

tests/ui/consts/control-flow/loop.rs

@@ -51,14 +51,14 @@ fn main() {
     let mut x = 0;
 
     for i in 0..4 {
-        //~^ ERROR: cannot use `for`
-        //~| ERROR: cannot use `for`
+        //~^ ERROR: `std::ops::Range<{integer}>: const Iterator` is not satisfied
+        //~| ERROR: `std::ops::Range<{integer}>: const Iterator` is not satisfied
         x += i;
     }
 
     for i in 0..4 {
-        //~^ ERROR: cannot use `for`
-        //~| ERROR: cannot use `for`
+        //~^ ERROR: `std::ops::Range<{integer}>: const Iterator` is not satisfied
+        //~| ERROR: `std::ops::Range<{integer}>: const Iterator` is not satisfied
         x += i;
     }
 

tests/ui/consts/control-flow/loop.stderr

@@ -1,37 +1,41 @@
-error[E0015]: cannot use `for` loop on `std::ops::Range<i32>` in constants
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/loop.rs:53:14
+   |
+LL |     for i in 0..4 {
+   |              ^^^^ required by a bound introduced by this call
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<{integer}>` to implement `const IntoIterator`
+
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
   --> $DIR/loop.rs:53:14
    |
 LL |     for i in 0..4 {
    |              ^^^^
    |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
 
-error[E0015]: cannot use `for` loop on `std::ops::Range<i32>` in constants
-  --> $DIR/loop.rs:53:14
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/loop.rs:59:14
    |
 LL |     for i in 0..4 {
-   |              ^^^^
+   |              ^^^^ required by a bound introduced by this call
    |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<{integer}>` to implement `const IntoIterator`
 
-error[E0015]: cannot use `for` loop on `std::ops::Range<i32>` in constants
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
   --> $DIR/loop.rs:59:14
    |
 LL |     for i in 0..4 {
    |              ^^^^
    |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
-
-error[E0015]: cannot use `for` loop on `std::ops::Range<i32>` in constants
-  --> $DIR/loop.rs:59:14
-   |
-LL |     for i in 0..4 {
-   |              ^^^^
-   |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
 
 error: aborting due to 4 previous errors
 
-For more information about this error, try `rustc --explain E0015`.
+For more information about this error, try `rustc --explain E0277`.

tests/ui/consts/different-fn-ptr-binders-during-ctfe.stable.stderr

@@ -1,10 +1,13 @@
-error: pointers cannot be reliably compared during const eval
+error[E0277]: pointers cannot be reliably compared during const eval
   --> $DIR/different-fn-ptr-binders-during-ctfe.rs:5:5
    |
 LL |     x == y
    |     ^^^^^^
    |
+note: trait `PartialEq` is implemented but not `const`
+  --> $SRC_DIR/core/src/ptr/mod.rs:LL:COL
    = note: see issue #53020 <https://github.com/rust-lang/rust/issues/53020> for more information
 
 error: aborting due to 1 previous error
 
+For more information about this error, try `rustc --explain E0277`.

tests/ui/consts/issue-25826.stderr

@@ -1,10 +1,13 @@
-error: pointers cannot be reliably compared during const eval
+error[E0277]: pointers cannot be reliably compared during const eval
   --> $DIR/issue-25826.rs:3:30
    |
 LL |     const A: bool = unsafe { id::<u8> as *const () < id::<u16> as *const () };
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+note: trait `PartialOrd` is implemented but not `const`
+  --> $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL
    = note: see issue #53020 <https://github.com/rust-lang/rust/issues/53020> for more information
 
 error: aborting due to 1 previous error
 
+For more information about this error, try `rustc --explain E0277`.

tests/ui/consts/min_const_fn/cmp_fn_pointers.stderr

@@ -1,10 +1,13 @@
-error: pointers cannot be reliably compared during const eval
+error[E0277]: pointers cannot be reliably compared during const eval
   --> $DIR/cmp_fn_pointers.rs:2:14
    |
 LL |     unsafe { x == y }
    |              ^^^^^^
    |
+note: trait `PartialEq` is implemented but not `const`
+  --> $SRC_DIR/core/src/ptr/mod.rs:LL:COL
    = note: see issue #53020 <https://github.com/rust-lang/rust/issues/53020> for more information
 
 error: aborting due to 1 previous error
 
+For more information about this error, try `rustc --explain E0277`.

tests/ui/feature-gates/feature-gate-diagnostic-on-const.rs

@@ -10,7 +10,7 @@
 
 const fn foo() {
     Foo == Foo;
-    //~^ ERROR: cannot call non-const operator in constant functions
+    //~^ ERROR: the trait bound `Foo: [const] PartialEq` is not satisfied
 }
 
 fn main() {}

tests/ui/feature-gates/feature-gate-diagnostic-on-const.stderr

@@ -1,16 +1,15 @@
-error[E0015]: cannot call non-const operator in constant functions
+error[E0277]: the trait bound `Foo: [const] PartialEq` is not satisfied
   --> $DIR/feature-gate-diagnostic-on-const.rs:12:5
    |
 LL |     Foo == Foo;
    |     ^^^^^^^^^^
    |
-note: impl defined here, but it is not `const`
+note: trait `PartialEq` is implemented but not `const`
   --> $DIR/auxiliary/diagnostic-on-const.rs:4:1
    |
 LL | impl PartialEq for Foo {
    | ^^^^^^^^^^^^^^^^^^^^^^
-   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0015`.
+For more information about this error, try `rustc --explain E0277`.

tests/ui/issues/issue-25901.rs

@@ -2,7 +2,7 @@
 struct B;
 
 static S: &'static B = &A;
-//~^ ERROR cannot perform non-const deref coercion
+//~^ ERROR the trait bound `A: const Deref` is not satisfied
 
 use std::ops::Deref;
 

tests/ui/issues/issue-25901.stderr

@@ -1,23 +1,14 @@
-error[E0015]: cannot perform non-const deref coercion on `A` in statics
+error[E0277]: the trait bound `A: const Deref` is not satisfied
   --> $DIR/issue-25901.rs:4:24
    |
 LL | static S: &'static B = &A;
    |                        ^^
    |
-   = note: attempting to deref into `B`
-note: deref defined here
-  --> $DIR/issue-25901.rs:10:5
+help: make the `impl` of trait `Deref` `const`
    |
-LL |     type Target = B;
-   |     ^^^^^^^^^^^
-note: impl defined here, but it is not `const`
-  --> $DIR/issue-25901.rs:9:1
-   |
-LL | impl Deref for A {
-   | ^^^^^^^^^^^^^^^^
-   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
-   = note: consider wrapping this expression in `std::sync::LazyLock::new(|| ...)`
+LL | impl const Deref for A {
+   |      +++++
 
 error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0015`.
+For more information about this error, try `rustc --explain E0277`.

tests/ui/mismatched_types/for-loop-in-vec-type-mismatchrs-50585.rs

@@ -2,4 +2,6 @@
 fn main() {
     |y: Vec<[(); for x in 0..2 {}]>| {};
     //~^ ERROR mismatched types
+    //~| ERROR  `std::ops::Range<{integer}>: const Iterator` is not satisfied
+    //~| ERROR  `std::ops::Range<{integer}>: const Iterator` is not satisfied
 }

tests/ui/mismatched_types/for-loop-in-vec-type-mismatchrs-50585.stderr

@@ -1,3 +1,22 @@
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/for-loop-in-vec-type-mismatchrs-50585.rs:3:27
+   |
+LL |     |y: Vec<[(); for x in 0..2 {}]>| {};
+   |                           ^^^^ required by a bound introduced by this call
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<{integer}>` to implement `const IntoIterator`
+
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/for-loop-in-vec-type-mismatchrs-50585.rs:3:27
+   |
+LL |     |y: Vec<[(); for x in 0..2 {}]>| {};
+   |                           ^^^^
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+
 error[E0308]: mismatched types
   --> $DIR/for-loop-in-vec-type-mismatchrs-50585.rs:3:18
    |
@@ -10,6 +29,7 @@ help: consider returning a value here
 LL |     |y: Vec<[(); for x in 0..2 {} /* `usize` value */]>| {};
    |                                   +++++++++++++++++++
 
-error: aborting due to 1 previous error
+error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0308`.
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.

tests/ui/never_type/issue-52443.rs

@@ -7,6 +7,6 @@ fn main() {
     //~^ WARN denote infinite loops with
 
     [(); { for _ in 0usize.. {}; 0}];
-    //~^ ERROR cannot use `for`
-    //~| ERROR cannot use `for`
+    //~^ ERROR `std::ops::RangeFrom<usize>: const Iterator` is not satisfied
+    //~| ERROR `std::ops::RangeFrom<usize>: const Iterator` is not satisfied
 }

tests/ui/never_type/issue-52443.stderr

@@ -31,24 +31,26 @@ help: give the `break` a value of the expected type
 LL |     [(); loop { break 42 }];
    |                       ++
 
-error[E0015]: cannot use `for` loop on `std::ops::RangeFrom<usize>` in constants
+error[E0277]: the trait bound `std::ops::RangeFrom<usize>: const Iterator` is not satisfied
   --> $DIR/issue-52443.rs:9:21
    |
 LL |     [(); { for _ in 0usize.. {}; 0}];
-   |                     ^^^^^^^^
+   |                     ^^^^^^^^ required by a bound introduced by this call
    |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::RangeFrom<usize>` to implement `const IntoIterator`
 
-error[E0015]: cannot use `for` loop on `std::ops::RangeFrom<usize>` in constants
+error[E0277]: the trait bound `std::ops::RangeFrom<usize>: const Iterator` is not satisfied
   --> $DIR/issue-52443.rs:9:21
    |
 LL |     [(); { for _ in 0usize.. {}; 0}];
    |                     ^^^^^^^^
    |
-   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
 
 error: aborting due to 4 previous errors; 1 warning emitted
 
-Some errors have detailed explanations: E0015, E0308.
-For more information about an error, try `rustc --explain E0015`.
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.

tests/ui/self/arbitrary-self-from-method-substs-ice.rs

@@ -9,9 +9,8 @@
 impl Foo {
     const fn get<R: Deref<Target = Self>>(self: R) -> u32 {
         //~^ ERROR invalid generic `self` parameter type
-        //~| ERROR destructor of `R` cannot be evaluated at compile-time
         self.0
-        //~^ ERROR cannot perform non-const deref coercion on `R` in constant functions
+        //~^ ERROR the trait bound `R: [const] Deref` is not satisfied
     }
 }
 

tests/ui/self/arbitrary-self-from-method-substs-ice.stderr

@@ -1,20 +1,8 @@
-error[E0015]: cannot perform non-const deref coercion on `R` in constant functions
-  --> $DIR/arbitrary-self-from-method-substs-ice.rs:13:9
+error[E0277]: the trait bound `R: [const] Deref` is not satisfied
+  --> $DIR/arbitrary-self-from-method-substs-ice.rs:12:9
    |
 LL |         self.0
-   |         ^^^^^^
-   |
-   = note: attempting to deref into `Foo`
-   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-
-error[E0493]: destructor of `R` cannot be evaluated at compile-time
-  --> $DIR/arbitrary-self-from-method-substs-ice.rs:10:43
-   |
-LL |     const fn get<R: Deref<Target = Self>>(self: R) -> u32 {
-   |                                           ^^^^ the destructor for this type cannot be evaluated in constant functions
-...
-LL |     }
-   |     - value is dropped here
+   |         ^^^^
 
 error[E0801]: invalid generic `self` parameter type: `R`
   --> $DIR/arbitrary-self-from-method-substs-ice.rs:10:49
@@ -25,7 +13,7 @@ LL |     const fn get<R: Deref<Target = Self>>(self: R) -> u32 {
    = note: type of `self` must not be a method generic parameter type
    = help: use a concrete type such as `self`, `&self`, `&mut self`, `self: Box<Self>`, `self: Rc<Self>`, `self: Arc<Self>`, or `self: Pin<P>` (where P is one of the previous types except `Self`)
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0015, E0493, E0801.
-For more information about an error, try `rustc --explain E0015`.
+Some errors have detailed explanations: E0277, E0801.
+For more information about an error, try `rustc --explain E0277`.

tests/ui/traits/const-traits/const_derives/derive-const-non-const-type.rs

@@ -10,6 +10,6 @@ fn default() -> A {
 
 #[derive_const(Default)]
 pub struct S(A);
-//~^ ERROR: cannot call non-const associated function
+//~^ ERROR: `A: [const] Default` is not satisfied
 
 fn main() {}

tests/ui/traits/const-traits/const_derives/derive-const-non-const-type.stderr

@@ -1,4 +1,4 @@
-error[E0015]: cannot call non-const associated function `<A as Default>::default` in constant functions
+error[E0277]: the trait bound `A: [const] Default` is not satisfied
   --> $DIR/derive-const-non-const-type.rs:12:14
    |
 LL | #[derive_const(Default)]
@@ -6,8 +6,11 @@ LL | #[derive_const(Default)]
 LL | pub struct S(A);
    |              ^
    |
-   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+help: make the `impl` of trait `Default` `const`
+   |
+LL | impl const Default for A {
+   |      +++++
 
 error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0015`.
+For more information about this error, try `rustc --explain E0277`.

tests/ui/traits/const-traits/cross-crate.rs

@@ -17,10 +17,9 @@ fn non_const_context() {
 const fn const_context() {
     #[cfg(any(stocknc, gatednc))]
     NonConst.func();
-    //[stocknc]~^ ERROR: cannot call
-    //[gatednc]~^^ ERROR: the trait bound
+    //[stocknc,gatednc]~^ ERROR: the trait bound
     Const.func();
-    //[stock,stocknc]~^ ERROR: cannot call
+    //[stock]~^ ERROR: cannot call
 }
 
 fn main() {}

tests/ui/traits/const-traits/cross-crate.stock.stderr

@@ -1,5 +1,5 @@
 error[E0658]: cannot call conditionally-const method `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
-  --> $DIR/cross-crate.rs:22:11
+  --> $DIR/cross-crate.rs:21:11
    |
 LL |     Const.func();
    |           ^^^^^^

tests/ui/traits/const-traits/cross-crate.stocknc.stderr

@@ -1,23 +1,15 @@
-error[E0015]: cannot call non-const method `<cross_crate::NonConst as cross_crate::MyTrait>::func` in constant functions
+error[E0277]: the trait bound `cross_crate::NonConst: [const] cross_crate::MyTrait` is not satisfied
   --> $DIR/cross-crate.rs:19:14
    |
 LL |     NonConst.func();
-   |              ^^^^^^
+   |              ^^^^
    |
-   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-
-error[E0658]: cannot call conditionally-const method `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
-  --> $DIR/cross-crate.rs:22:11
+note: trait `MyTrait` is implemented but not `const`
+  --> $DIR/auxiliary/cross-crate.rs:11:1
    |
-LL |     Const.func();
-   |           ^^^^^^
-   |
-   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-   = note: see issue #143874 <https://github.com/rust-lang/rust/issues/143874> for more information
-   = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+LL | impl MyTrait for NonConst {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
-Some errors have detailed explanations: E0015, E0658.
-For more information about an error, try `rustc --explain E0015`.
+For more information about this error, try `rustc --explain E0277`.

tests/ui/traits/const-traits/gate.rs

@@ -3,6 +3,7 @@
 fn main() {
     (const || {})();
     //~^ ERROR: const closures are experimental
+    //~| ERROR: the trait bound `{closure@$DIR/gate.rs:4:6: 4:14}: [const] Fn()` is not satisfied
 }
 
 macro_rules! e {

tests/ui/traits/const-traits/gate.stderr

@@ -9,7 +9,7 @@ LL |     (const || {})();
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: const closures are experimental
-  --> $DIR/gate.rs:12:5
+  --> $DIR/gate.rs:13:5
    |
 LL | e!((const || {}));
    |     ^^^^^
@@ -18,6 +18,13 @@ LL | e!((const || {}));
    = help: add `#![feature(const_closures)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error: aborting due to 2 previous errors
+error[E0277]: the trait bound `{closure@$DIR/gate.rs:4:6: 4:14}: [const] Fn()` is not satisfied
+  --> $DIR/gate.rs:4:5
+   |
+LL |     (const || {})();
+   |     ^^^^^^^^^^^^^^^
 
-For more information about this error, try `rustc --explain E0658`.
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0277, E0658.
+For more information about an error, try `rustc --explain E0277`.

tests/ui/traits/const-traits/super-traits-fail-3.nyn.stderr

@@ -83,15 +83,13 @@ help: enable `#![feature(const_trait_impl)]` in your crate and mark `Bar` as `co
 LL | #[cfg(any(yyn, ynn, nyn, nnn))] const trait Bar: [const] Foo {}
    |                                 +++++
 
-error[E0015]: cannot call non-const method `<T as Foo>::a` in constant functions
+error[E0277]: the trait bound `T: [const] Foo` is not satisfied
   --> $DIR/super-traits-fail-3.rs:38:7
    |
 LL |     x.a();
-   |       ^^^
-   |
-   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+   |       ^
 
 error: aborting due to 9 previous errors
 
-Some errors have detailed explanations: E0015, E0658.
-For more information about an error, try `rustc --explain E0015`.
+Some errors have detailed explanations: E0277, E0658.
+For more information about an error, try `rustc --explain E0277`.

tests/ui/traits/const-traits/super-traits-fail-3.rs

@@ -36,8 +36,8 @@ const fn foo<T: [const] Bar>(x: &T) {
     //[yyn,ynn,nyn,nnn]~| ERROR: `[const]` can only be applied to `const` traits
     //[nyy,nyn,nny,nnn]~^^^ ERROR: const trait impls are experimental
     x.a();
-    //[yyn]~^ ERROR: the trait bound `T: [const] Foo` is not satisfied
-    //[ynn,yny,nny,nnn,nyn]~^^ ERROR: cannot call non-const method `<T as Foo>::a` in constant functions
+    //[yyn,nyn]~^ ERROR: the trait bound `T: [const] Foo` is not satisfied
+    //[ynn,yny,nny,nnn]~^^ ERROR: cannot call non-const method `<T as Foo>::a` in constant functions
     //[nyy]~^^^ ERROR: cannot call conditionally-const method `<T as Foo>::a` in constant functions
 }
 

tests/ui/typeck/for-in-const-eval.rs

@@ -2,4 +2,6 @@
 fn main() {
     Vec::<[(); 1 + for x in 0..1 {}]>::new();
     //~^ ERROR cannot add
+    //~| ERROR const Iterator` is not satisfied
+    //~| ERROR const Iterator` is not satisfied
 }

tests/ui/typeck/for-in-const-eval.stderr

@@ -1,3 +1,22 @@
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/for-in-const-eval.rs:3:29
+   |
+LL |     Vec::<[(); 1 + for x in 0..1 {}]>::new();
+   |                             ^^^^ required by a bound introduced by this call
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+   = note: required for `std::ops::Range<{integer}>` to implement `const IntoIterator`
+
+error[E0277]: the trait bound `std::ops::Range<{integer}>: const Iterator` is not satisfied
+  --> $DIR/for-in-const-eval.rs:3:29
+   |
+LL |     Vec::<[(); 1 + for x in 0..1 {}]>::new();
+   |                             ^^^^
+   |
+note: trait `Iterator` is implemented but not `const`
+  --> $SRC_DIR/core/src/iter/range.rs:LL:COL
+
 error[E0277]: cannot add `()` to `{integer}`
   --> $DIR/for-in-const-eval.rs:3:18
    |
@@ -16,6 +35,6 @@ LL |     Vec::<[(); 1 + for x in 0..1 {}]>::new();
              `&f64` implements `Add`
            and 56 others
 
-error: aborting due to 1 previous error
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0277`.