Rollup merge of #100238 - Bryysen:master, r=cjgillot

Further improve error message for E0081

Closes #97533

8 files changed, 78 insertions, 101 deletions

diff --git a/src/test/ui/enum/enum-discrim-autosizing.rs b/src/test/ui/enum/enum-discrim-autosizing.rs
index 27fab1bb505..fc94d281c77 100644
--- a/src/test/ui/enum/enum-discrim-autosizing.rs
+++ b/src/test/ui/enum/enum-discrim-autosizing.rs
@@ -6,9 +6,9 @@
 enum Eu64 {
     //~^ ERROR discriminant value `0` assigned more than once
     Au64 = 0,
-    //~^NOTE first assignment of `0`
+    //~^NOTE `0` assigned here
     Bu64 = 0x8000_0000_0000_0000
-    //~^NOTE second assignment of `0` (overflowed from `9223372036854775808`)
+    //~^NOTE `0` (overflowed from `9223372036854775808`) assigned here
 }
 
 fn main() {}
diff --git a/src/test/ui/enum/enum-discrim-autosizing.stderr b/src/test/ui/enum/enum-discrim-autosizing.stderr
index eacea86d67e..be3d7c64e28 100644
--- a/src/test/ui/enum/enum-discrim-autosizing.stderr
+++ b/src/test/ui/enum/enum-discrim-autosizing.stderr
@@ -5,10 +5,10 @@ LL | enum Eu64 {
    | ^^^^^^^^^
 LL |
 LL |     Au64 = 0,
-   |            - first assignment of `0`
+   |            - `0` assigned here
 LL |
 LL |     Bu64 = 0x8000_0000_0000_0000
-   |            --------------------- second assignment of `0` (overflowed from `9223372036854775808`)
+   |            --------------------- `0` (overflowed from `9223372036854775808`) assigned here
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/error-codes/E0081.rs b/src/test/ui/error-codes/E0081.rs
index 5aa6a786339..f53fda864d6 100644
--- a/src/test/ui/error-codes/E0081.rs
+++ b/src/test/ui/error-codes/E0081.rs
@@ -1,9 +1,9 @@
 enum Enum {
     //~^ ERROR discriminant value `3` assigned more than once
     P = 3,
-    //~^ NOTE first assignment of `3`
+    //~^ NOTE `3` assigned here
     X = 3,
-    //~^ NOTE second assignment of `3`
+    //~^ NOTE `3` assigned here
     Y = 5
 }
 
@@ -11,20 +11,43 @@ enum Enum {
 enum EnumOverflowRepr {
     //~^ ERROR discriminant value `1` assigned more than once
     P = 257,
-    //~^ NOTE first assignment of `1` (overflowed from `257`)
+    //~^ NOTE `1` (overflowed from `257`) assigned here
     X = 513,
-    //~^ NOTE second assignment of `1` (overflowed from `513`)
+    //~^ NOTE `1` (overflowed from `513`) assigned here
 }
 
 #[repr(i8)]
 enum NegDisEnum {
     //~^ ERROR discriminant value `-1` assigned more than once
     First = -1,
-    //~^ NOTE first assignment of `-1`
+    //~^ NOTE `-1` assigned here
     Second = -2,
-    //~^ NOTE assigned discriminant for `Last` was incremented from this discriminant
+    //~^ NOTE discriminant for `Last` incremented from this startpoint (`Second` + 1 variant later => `Last` = -1)
     Last,
-    //~^ NOTE second assignment of `-1`
+    //~^ NOTE `-1` assigned here
+}
+
+enum MultipleDuplicates {
+    //~^ ERROR discriminant value `0` assigned more than once
+    //~^^ ERROR discriminant value `-2` assigned more than once
+    V0,
+    //~^ NOTE `0` assigned here
+    V1 = 0,
+    //~^ NOTE `0` assigned here
+    V2,
+    V3,
+    V4 = 0,
+    //~^ NOTE `0` assigned here
+    V5 = -2,
+    //~^ NOTE discriminant for `V7` incremented from this startpoint (`V5` + 2 variants later => `V7` = 0)
+    //~^^ NOTE `-2` assigned here
+    V6,
+    V7,
+    //~^ NOTE `0` assigned here
+    V8 = -3,
+    //~^ NOTE discriminant for `V9` incremented from this startpoint (`V8` + 1 variant later => `V9` = -2)
+    V9,
+    //~^ NOTE `-2` assigned here
 }
 
 fn main() {
diff --git a/src/test/ui/error-codes/E0081.stderr b/src/test/ui/error-codes/E0081.stderr
index ff6113646bb..64562fefc86 100644
--- a/src/test/ui/error-codes/E0081.stderr
+++ b/src/test/ui/error-codes/E0081.stderr
@@ -5,10 +5,10 @@ LL | enum Enum {
    | ^^^^^^^^^
 LL |
 LL |     P = 3,
-   |         - first assignment of `3`
+   |         - `3` assigned here
 LL |
 LL |     X = 3,
-   |         - second assignment of `3`
+   |         - `3` assigned here
 
 error[E0081]: discriminant value `1` assigned more than once
   --> $DIR/E0081.rs:11:1
@@ -17,10 +17,10 @@ LL | enum EnumOverflowRepr {
    | ^^^^^^^^^^^^^^^^^^^^^
 LL |
 LL |     P = 257,
-   |         --- first assignment of `1` (overflowed from `257`)
+   |         --- `1` (overflowed from `257`) assigned here
 LL |
 LL |     X = 513,
-   |         --- second assignment of `1` (overflowed from `513`)
+   |         --- `1` (overflowed from `513`) assigned here
 
 error[E0081]: discriminant value `-1` assigned more than once
   --> $DIR/E0081.rs:20:1
@@ -29,14 +29,50 @@ LL | enum NegDisEnum {
    | ^^^^^^^^^^^^^^^
 LL |
 LL |     First = -1,
-   |             -- first assignment of `-1`
+   |             -- `-1` assigned here
 LL |
 LL |     Second = -2,
-   |     ----------- assigned discriminant for `Last` was incremented from this discriminant
+   |     ----------- discriminant for `Last` incremented from this startpoint (`Second` + 1 variant later => `Last` = -1)
 LL |
 LL |     Last,
-   |     ---- second assignment of `-1`
+   |     ---- `-1` assigned here
 
-error: aborting due to 3 previous errors
+error[E0081]: discriminant value `0` assigned more than once
+  --> $DIR/E0081.rs:30:1
+   |
+LL | enum MultipleDuplicates {
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL |     V0,
+   |     -- `0` assigned here
+LL |
+LL |     V1 = 0,
+   |          - `0` assigned here
+...
+LL |     V4 = 0,
+   |          - `0` assigned here
+LL |
+LL |     V5 = -2,
+   |     ------- discriminant for `V7` incremented from this startpoint (`V5` + 2 variants later => `V7` = 0)
+...
+LL |     V7,
+   |     -- `0` assigned here
+
+error[E0081]: discriminant value `-2` assigned more than once
+  --> $DIR/E0081.rs:30:1
+   |
+LL | enum MultipleDuplicates {
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL |     V5 = -2,
+   |          -- `-2` assigned here
+...
+LL |     V8 = -3,
+   |     ------- discriminant for `V9` incremented from this startpoint (`V8` + 1 variant later => `V9` = -2)
+LL |
+LL |     V9,
+   |     -- `-2` assigned here
+
+error: aborting due to 5 previous errors
 
 For more information about this error, try `rustc --explain E0081`.
diff --git a/src/test/ui/issues/issue-15524.rs b/src/test/ui/issues/issue-15524.rs
deleted file mode 100644
index 565db2d0fca..00000000000
--- a/src/test/ui/issues/issue-15524.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-const N: isize = 1;
-
-enum Foo {
-    //~^ ERROR discriminant value `1` assigned more than once
-    //~| ERROR discriminant value `1` assigned more than once
-    //~| ERROR discriminant value `1` assigned more than once
-    A = 1,
-    B = 1,
-    C = 0,
-    D,
-
-    E = N,
-
-}
-
-fn main() {}
diff --git a/src/test/ui/issues/issue-15524.stderr b/src/test/ui/issues/issue-15524.stderr
deleted file mode 100644
index 1195e0a346d..00000000000
--- a/src/test/ui/issues/issue-15524.stderr
+++ /dev/null
@@ -1,40 +0,0 @@
-error[E0081]: discriminant value `1` assigned more than once
-  --> $DIR/issue-15524.rs:3:1
-   |
-LL | enum Foo {
-   | ^^^^^^^^
-...
-LL |     A = 1,
-   |         - first assignment of `1`
-LL |     B = 1,
-   |         - second assignment of `1`
-
-error[E0081]: discriminant value `1` assigned more than once
-  --> $DIR/issue-15524.rs:3:1
-   |
-LL | enum Foo {
-   | ^^^^^^^^
-...
-LL |     A = 1,
-   |         - first assignment of `1`
-LL |     B = 1,
-LL |     C = 0,
-   |     ----- assigned discriminant for `D` was incremented from this discriminant
-LL |     D,
-   |     - second assignment of `1`
-
-error[E0081]: discriminant value `1` assigned more than once
-  --> $DIR/issue-15524.rs:3:1
-   |
-LL | enum Foo {
-   | ^^^^^^^^
-...
-LL |     A = 1,
-   |         - first assignment of `1`
-...
-LL |     E = N,
-   |         - second assignment of `1`
-
-error: aborting due to 3 previous errors
-
-For more information about this error, try `rustc --explain E0081`.
diff --git a/src/test/ui/tag-variant-disr-dup.rs b/src/test/ui/tag-variant-disr-dup.rs
deleted file mode 100644
index e497f993da2..00000000000
--- a/src/test/ui/tag-variant-disr-dup.rs
+++ /dev/null
@@ -1,12 +0,0 @@
-// Black and White have the same discriminator value ...
-
-enum Color {
-    //~^ ERROR discriminant value `0` assigned more than once
-    Red = 0xff0000,
-    Green = 0x00ff00,
-    Blue = 0x0000ff,
-    Black = 0x000000,
-    White = 0x000000,
-}
-
-fn main() { }
diff --git a/src/test/ui/tag-variant-disr-dup.stderr b/src/test/ui/tag-variant-disr-dup.stderr
deleted file mode 100644
index 6b1ba43d2ba..00000000000
--- a/src/test/ui/tag-variant-disr-dup.stderr
+++ /dev/null
@@ -1,14 +0,0 @@
-error[E0081]: discriminant value `0` assigned more than once
-  --> $DIR/tag-variant-disr-dup.rs:3:1
-   |
-LL | enum Color {
-   | ^^^^^^^^^^
-...
-LL |     Black = 0x000000,
-   |             -------- first assignment of `0`
-LL |     White = 0x000000,
-   |             -------- second assignment of `0`
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0081`.