1 files changed, 71 insertions, 0 deletions
diff --git a/src/test/ui/consts/const-eval/promoted_errors.rs b/src/test/ui/consts/const-eval/promoted_errors.rs
new file mode 100644
index 000000000..eb891de33
--- /dev/null
+++ b/src/test/ui/consts/const-eval/promoted_errors.rs
@@ -0,0 +1,71 @@
+// revisions: noopt opt opt_with_overflow_checks
+//[noopt]compile-flags: -C opt-level=0
+//[opt]compile-flags: -O
+//[opt_with_overflow_checks]compile-flags: -C overflow-checks=on -O
+
+// build-pass
+// ignore-pass (test emits codegen-time warnings and verifies that they are not errors)
+
+//! This test ensures that when we promote code that fails to evaluate, the build still succeeds.
+
+#![warn(const_err, arithmetic_overflow, unconditional_panic)]
+
+// The only way to have promoteds that fail is in `const fn` called from `const`/`static`.
+const fn overflow() -> u32 {
+    0 - 1
+    //[opt_with_overflow_checks,noopt]~^ WARN any use of this value will cause an error
+    //[opt_with_overflow_checks,noopt]~| WARN this was previously accepted by the compiler
+    //~^^^ WARN this arithmetic operation will overflow
+}
+const fn div_by_zero1() -> i32 {
+    1 / 0
+    //[opt]~^ WARN any use of this value will cause an error
+    //[opt]~| WARN this was previously accepted by the compiler but is being phased out
+    //~^^^ WARN this operation will panic at runtime
+}
+const fn div_by_zero2() -> i32 {
+    1 / (1 - 1)
+    //~^ WARN this operation will panic at runtime
+}
+const fn div_by_zero3() -> i32 {
+    1 / (false as i32)
+    //~^ WARN this operation will panic at runtime
+}
+const fn oob() -> i32 {
+    [1, 2, 3][4]
+    //~^ WARN this operation will panic at runtime
+}
+
+// An unused constant containing failing promoteds.
+// This should work as long as `const_err` can be turned into just a warning;
+// once it turns into a hard error, just remove `X`.
+const X: () = {
+    let _x: &'static u32 = &overflow();
+    //[opt_with_overflow_checks,noopt]~^ WARN any use of this value will cause an error
+    //[opt_with_overflow_checks,noopt]~| WARN this was previously accepted by the compiler
+    let _x: &'static i32 = &div_by_zero1();
+    //[opt]~^ WARN any use of this value will cause an error
+    //[opt]~| WARN this was previously accepted by the compiler but is being phased out
+    let _x: &'static i32 = &div_by_zero2();
+    let _x: &'static i32 = &div_by_zero3();
+    let _x: &'static i32 = &oob();
+};
+
+const fn mk_false() -> bool { false }
+
+// An actually used constant referencing failing promoteds in dead code.
+// This needs to always work.
+const Y: () = {
+    if mk_false() {
+        let _x: &'static u32 = &overflow();
+        let _x: &'static i32 = &div_by_zero1();
+        let _x: &'static i32 = &div_by_zero2();
+        let _x: &'static i32 = &div_by_zero3();
+        let _x: &'static i32 = &oob();
+    }
+    ()
+};
+
+fn main() {
+    let _y = Y;
+}