Add a forever unstable opt-out of const qualification checks

6 files changed, 126 insertions, 0 deletions

diff --git a/src/test/ui/consts/miri_unleashed/assoc_const.rs b/src/test/ui/consts/miri_unleashed/assoc_const.rs
new file mode 100644
index 00000000000..b8959667cc2
--- /dev/null
+++ b/src/test/ui/consts/miri_unleashed/assoc_const.rs
@@ -0,0 +1,30 @@
+// compile-flags: -Zunleash-the-miri-inside-of-you
+#![allow(const_err)]
+
+// a test demonstrating why we do need to run static const qualification on associated constants
+// instead of just checking the final constant
+
+trait Foo<T> {
+    const X: T;
+}
+
+trait Bar<T, U: Foo<T>> {
+    const F: u32 = (U::X, 42).1; //~ WARN skipping const checks
+}
+
+impl Foo<u32> for () {
+    const X: u32 = 42;
+}
+impl Foo<Vec<u32>> for String {
+    const X: Vec<u32> = Vec::new();
+}
+
+impl Bar<u32, ()> for () {}
+impl Bar<Vec<u32>, String> for String {}
+
+fn main() {
+    // this is fine, but would have been forbidden by the static checks on `F`
+    let x = <() as Bar<u32, ()>>::F;
+    // this test only causes errors due to the line below, so post-monomorphization
+    let y = <String as Bar<Vec<u32>, String>>::F; //~ ERROR erroneous constant
+}
diff --git a/src/test/ui/consts/miri_unleashed/assoc_const.stderr b/src/test/ui/consts/miri_unleashed/assoc_const.stderr
new file mode 100644
index 00000000000..a40f8d46d0a
--- /dev/null
+++ b/src/test/ui/consts/miri_unleashed/assoc_const.stderr
@@ -0,0 +1,15 @@
+warning: skipping const checks
+  --> $DIR/assoc_const.rs:12:31
+   |
+LL |     const F: u32 = (U::X, 42).1; //~ WARN skipping const checks
+   |                               ^
+
+error[E0080]: erroneous constant used
+  --> $DIR/assoc_const.rs:29:13
+   |
+LL |     let y = <String as Bar<Vec<u32>, String>>::F; //~ ERROR erroneous constant
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ referenced constant has errors
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/consts/miri_unleashed/assoc_const_2.rs b/src/test/ui/consts/miri_unleashed/assoc_const_2.rs
new file mode 100644
index 00000000000..c87b6389848
--- /dev/null
+++ b/src/test/ui/consts/miri_unleashed/assoc_const_2.rs
@@ -0,0 +1,28 @@
+#![allow(const_err)]
+
+// a test demonstrating that const qualification cannot prevent monomorphization time errors
+
+trait Foo {
+    const X: u32;
+}
+
+trait Bar<U: Foo> {
+    const F: u32 = 100 / U::X;
+}
+
+impl Foo for () {
+    const X: u32 = 42;
+}
+
+impl Foo for String {
+    const X: u32 = 0;
+}
+
+impl Bar<()> for () {}
+impl Bar<String> for String {}
+
+fn main() {
+    let x = <() as Bar<()>>::F;
+    // this test only causes errors due to the line below, so post-monomorphization
+    let y = <String as Bar<String>>::F; //~ ERROR erroneous constant
+}
diff --git a/src/test/ui/consts/miri_unleashed/assoc_const_2.stderr b/src/test/ui/consts/miri_unleashed/assoc_const_2.stderr
new file mode 100644
index 00000000000..77aab31d26e
--- /dev/null
+++ b/src/test/ui/consts/miri_unleashed/assoc_const_2.stderr
@@ -0,0 +1,9 @@
+error[E0080]: erroneous constant used
+  --> $DIR/assoc_const_2.rs:27:13
+   |
+LL |     let y = <String as Bar<String>>::F; //~ ERROR erroneous constant
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ referenced constant has errors
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/consts/miri_unleashed/feature-gate-unleash_the_miri_inside_of_you.rs b/src/test/ui/consts/miri_unleashed/feature-gate-unleash_the_miri_inside_of_you.rs
new file mode 100644
index 00000000000..5fb92535502
--- /dev/null
+++ b/src/test/ui/consts/miri_unleashed/feature-gate-unleash_the_miri_inside_of_you.rs
@@ -0,0 +1,27 @@
+#![allow(const_err)]
+
+// a test demonstrating why we do need to run static const qualification on associated constants
+// instead of just checking the final constant
+
+trait Foo<T> {
+    const X: T;
+}
+
+trait Bar<T, U: Foo<T>> {
+    const F: u32 = (U::X, 42).1; //~ ERROR destructors cannot be evaluated at compile-time
+}
+
+impl Foo<u32> for () {
+    const X: u32 = 42;
+}
+impl Foo<Vec<u32>> for String {
+    const X: Vec<u32> = Vec::new(); //~ ERROR not yet stable as a const fn
+}
+
+impl Bar<u32, ()> for () {}
+impl Bar<Vec<u32>, String> for String {}
+
+fn main() {
+    let x = <() as Bar<u32, ()>>::F;
+    let y = <String as Bar<Vec<u32>, String>>::F;
+}
diff --git a/src/test/ui/consts/miri_unleashed/feature-gate-unleash_the_miri_inside_of_you.stderr b/src/test/ui/consts/miri_unleashed/feature-gate-unleash_the_miri_inside_of_you.stderr
new file mode 100644
index 00000000000..e23ed1c6206
--- /dev/null
+++ b/src/test/ui/consts/miri_unleashed/feature-gate-unleash_the_miri_inside_of_you.stderr
@@ -0,0 +1,17 @@
+error[E0493]: destructors cannot be evaluated at compile-time
+  --> $DIR/feature-gate-unleash_the_miri_inside_of_you.rs:11:20
+   |
+LL |     const F: u32 = (U::X, 42).1; //~ ERROR destructors cannot be evaluated at compile-time
+   |                    ^^^^^^^^^^ constants cannot evaluate destructors
+
+error: `<std::vec::Vec<T>>::new` is not yet stable as a const fn
+  --> $DIR/feature-gate-unleash_the_miri_inside_of_you.rs:18:25
+   |
+LL |     const X: Vec<u32> = Vec::new(); //~ ERROR not yet stable as a const fn
+   |                         ^^^^^^^^^^
+   |
+   = help: add `#![feature(const_vec_new)]` to the crate attributes to enable
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0493`.