Add filtering options to `rustc_on_unimplemented`

 - filter error on the evaluated value of `Self`
 - filter error on the evaluated value of the type arguments
 - add argument to include custom note in diagnostic
 - allow the parser to parse `Self` when processing attributes
 - add custom message to binops

2 files changed, 125 insertions, 20 deletions

diff --git a/src/libcore/ops/arith.rs b/src/libcore/ops/arith.rs
index 8b3d662a6db..59a18d6cb75 100644
--- a/src/libcore/ops/arith.rs
+++ b/src/libcore/ops/arith.rs
@@ -75,7 +75,93 @@
 /// ```
 #[lang = "add"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} + {RHS}`"]
+#[rustc_on_unimplemented(
+    on(
+        any(
+            all(_Self="i128", RHS="i64"),
+            all(_Self="i128", RHS="i32"),
+            all(_Self="i128", RHS="i16"),
+            all(_Self="i128", RHS="i8"),
+            all(_Self="i64",  RHS="i32"),
+            all(_Self="i64",  RHS="i16"),
+            all(_Self="i64",  RHS="i8"),
+            all(_Self="i32",  RHS="i16"),
+            all(_Self="i32",  RHS="i8"),
+            all(_Self="i16",  RHS="i8"),
+            all(_Self="u128", RHS="u64"),
+            all(_Self="u128", RHS="u32"),
+            all(_Self="u128", RHS="u16"),
+            all(_Self="u128", RHS="u8"),
+            all(_Self="u64",  RHS="u32"),
+            all(_Self="u64",  RHS="u16"),
+            all(_Self="u64",  RHS="u8"),
+            all(_Self="u32",  RHS="u16"),
+            all(_Self="u32",  RHS="u8"),
+            all(_Self="u16",  RHS="u8"),
+            all(_Self="f64",  RHS="i32"),
+            all(_Self="f64",  RHS="i16"),
+            all(_Self="f64",  RHS="i8"),
+            all(_Self="f64",  RHS="u32"),
+            all(_Self="f64",  RHS="u16"),
+            all(_Self="f64",  RHS="u8"),
+            all(_Self="f32",  RHS="i16"),
+            all(_Self="f32",  RHS="i8"),
+            all(_Self="f32",  RHS="u16"),
+            all(_Self="f32",  RHS="u8"),
+        ),
+        message="cannot add `{RHS}` to `{Self}`",
+        label="no implementation for `{Self} + {RHS}`, but you can safely cast \
+               `{RHS}` into `{Self}` using `as {Self}`",
+    ),
+    on(
+        any(
+            all(RHS="i128", _Self="i64"),
+            all(RHS="i128", _Self="i32"),
+            all(RHS="i128", _Self="i16"),
+            all(RHS="i128", _Self="i8"),
+            all(RHS="i64",  _Self="i32"),
+            all(RHS="i64",  _Self="i16"),
+            all(RHS="i64",  _Self="i8"),
+            all(RHS="i32",  _Self="i16"),
+            all(RHS="i32",  _Self="i8"),
+            all(RHS="i16",  _Self="i8"),
+            all(RHS="u128", _Self="u64"),
+            all(RHS="u128", _Self="u32"),
+            all(RHS="u128", _Self="u16"),
+            all(RHS="u128", _Self="u8"),
+            all(RHS="u64",  _Self="u32"),
+            all(RHS="u64",  _Self="u16"),
+            all(RHS="u64",  _Self="u8"),
+            all(RHS="u32",  _Self="u16"),
+            all(RHS="u32",  _Self="u8"),
+            all(RHS="u16",  _Self="u8"),
+            all(RHS="f64",  _Self="i32"),
+            all(RHS="f64",  _Self="i16"),
+            all(RHS="f64",  _Self="i8"),
+            all(RHS="f64",  _Self="u32"),
+            all(RHS="f64",  _Self="u16"),
+            all(RHS="f64",  _Self="u8"),
+            all(RHS="f32",  _Self="i16"),
+            all(RHS="f32",  _Self="i8"),
+            all(RHS="f32",  _Self="u16"),
+            all(RHS="f32",  _Self="u8"),
+        ),
+        message="cannot add `{RHS}` to `{Self}`",
+        label="no implementation for `{Self} + {RHS}`, but you can safely turn \
+               `{Self}` into `{RHS}` using `as {RHS}`",
+    ),
+    on(
+        all(_Self="{integer}", RHS="{float}"),
+        message="cannot add a float to an integer",
+        label="no implementation for `{Self} + {RHS}`",
+    ),
+    on(
+        all(_Self="{float}", RHS="{integer}"),
+        message="cannot add an integer to a float",
+        label="no implementation for `{Self} + {RHS}`",
+    ),
+    message="cannot add `{RHS}` to `{Self}`",
+    label="no implementation for `{Self} + {RHS}`")]
 pub trait Add<RHS=Self> {
     /// The resulting type after applying the `+` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -170,7 +256,8 @@ add_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// ```
 #[lang = "sub"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} - {RHS}`"]
+#[rustc_on_unimplemented(message="cannot substract `{RHS}` from `{Self}`",
+                         label="no implementation for `{Self} - {RHS}`")]
 pub trait Sub<RHS=Self> {
     /// The resulting type after applying the `-` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -287,7 +374,8 @@ sub_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// ```
 #[lang = "mul"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} * {RHS}`"]
+#[rustc_on_unimplemented(message="cannot multiply `{RHS}` to `{Self}`",
+                         label="no implementation for `{Self} * {RHS}`")]
 pub trait Mul<RHS=Self> {
     /// The resulting type after applying the `*` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -408,7 +496,8 @@ mul_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// ```
 #[lang = "div"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} / {RHS}`"]
+#[rustc_on_unimplemented(message="cannot divide `{Self}` by `{RHS}`",
+                         label="no implementation for `{Self} / {RHS}`")]
 pub trait Div<RHS=Self> {
     /// The resulting type after applying the `/` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -490,7 +579,8 @@ div_impl_float! { f32 f64 }
 /// ```
 #[lang = "rem"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} % {RHS}`"]
+#[rustc_on_unimplemented(message="cannot mod `{Self}` by `{RHS}`",
+                         label="no implementation for `{Self} % {RHS}`")]
 pub trait Rem<RHS=Self> {
     /// The resulting type after applying the `%` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -647,7 +737,8 @@ neg_impl_numeric! { isize i8 i16 i32 i64 i128 f32 f64 }
 /// ```
 #[lang = "add_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} += {Rhs}`"]
+#[rustc_on_unimplemented(message="cannot add-assign `{Rhs}` to `{Self}`",
+                         label="no implementation for `{Self} += {Rhs}`")]
 pub trait AddAssign<Rhs=Self> {
     /// Performs the `+=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]
@@ -700,7 +791,8 @@ add_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// ```
 #[lang = "sub_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} -= {Rhs}`"]
+#[rustc_on_unimplemented(message="cannot substract-assign `{Rhs}` from `{Self}`",
+                         label="no implementation for `{Self} -= {Rhs}`")]
 pub trait SubAssign<Rhs=Self> {
     /// Performs the `-=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]
@@ -744,7 +836,8 @@ sub_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// ```
 #[lang = "mul_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} *= {Rhs}`"]
+#[rustc_on_unimplemented(message="cannot multiply-assign `{Rhs}` to `{Self}`",
+                         label="no implementation for `{Self} *= {Rhs}`")]
 pub trait MulAssign<Rhs=Self> {
     /// Performs the `*=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]
@@ -788,7 +881,8 @@ mul_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// ```
 #[lang = "div_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} /= {Rhs}`"]
+#[rustc_on_unimplemented(message="cannot divide-assign `{Self}` by `{Rhs}`",
+                         label="no implementation for `{Self} /= {Rhs}`")]
 pub trait DivAssign<Rhs=Self> {
     /// Performs the `/=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]
@@ -835,7 +929,8 @@ div_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// ```
 #[lang = "rem_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} %= {Rhs}`"]
+#[rustc_on_unimplemented(message="cannot mod-assign `{Self}` by `{Rhs}``",
+                         label="no implementation for `{Self} %= {Rhs}`")]
 pub trait RemAssign<Rhs=Self> {
     /// Performs the `%=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]
diff --git a/src/libcore/ops/bit.rs b/src/libcore/ops/bit.rs
index 7ac5fc4debf..a0ecd6cf75c 100644
--- a/src/libcore/ops/bit.rs
+++ b/src/libcore/ops/bit.rs
@@ -120,7 +120,8 @@ not_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// ```
 #[lang = "bitand"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} & {RHS}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} & {RHS}`",
+                         label="no implementation for `{Self} & {RHS}`")]
 pub trait BitAnd<RHS=Self> {
     /// The resulting type after applying the `&` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -201,7 +202,8 @@ bitand_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// ```
 #[lang = "bitor"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} | {RHS}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} | {RHS}`",
+                         label="no implementation for `{Self} | {RHS}`")]
 pub trait BitOr<RHS=Self> {
     /// The resulting type after applying the `|` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -285,7 +287,8 @@ bitor_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// ```
 #[lang = "bitxor"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} ^ {RHS}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} ^ {RHS}`",
+                         label="no implementation for `{Self} ^ {RHS}`")]
 pub trait BitXor<RHS=Self> {
     /// The resulting type after applying the `^` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -365,7 +368,8 @@ bitxor_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// ```
 #[lang = "shl"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} << {RHS}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} << {RHS}`",
+                         label="no implementation for `{Self} << {RHS}`")]
 pub trait Shl<RHS> {
     /// The resulting type after applying the `<<` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -466,7 +470,8 @@ shl_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 isize i128 }
 /// ```
 #[lang = "shr"]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} >> {RHS}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} >> {RHS}`",
+                         label="no implementation for `{Self} >> {RHS}`")]
 pub trait Shr<RHS> {
     /// The resulting type after applying the `>>` operator.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -579,7 +584,8 @@ shr_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize }
 /// ```
 #[lang = "bitand_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} &= {Rhs}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} &= {Rhs}`",
+                         label="no implementation for `{Self} &= {Rhs}`")]
 pub trait BitAndAssign<Rhs=Self> {
     /// Performs the `&=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]
@@ -626,7 +632,8 @@ bitand_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// ```
 #[lang = "bitor_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} |= {Rhs}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} |= {Rhs}`",
+                         label="no implementation for `{Self} |= {Rhs}`")]
 pub trait BitOrAssign<Rhs=Self> {
     /// Performs the `|=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]
@@ -673,7 +680,8 @@ bitor_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// ```
 #[lang = "bitxor_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} ^= {Rhs}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} ^= {Rhs}`",
+                         label="no implementation for `{Self} ^= {Rhs}`")]
 pub trait BitXorAssign<Rhs=Self> {
     /// Performs the `^=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]
@@ -718,7 +726,8 @@ bitxor_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// ```
 #[lang = "shl_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} <<= {Rhs}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} <<= {Rhs}`",
+                         label="no implementation for `{Self} <<= {Rhs}`")]
 pub trait ShlAssign<Rhs> {
     /// Performs the `<<=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]
@@ -784,7 +793,8 @@ shl_assign_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize }
 /// ```
 #[lang = "shr_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
-#[rustc_on_unimplemented = "no implementation for `{Self} >>= {Rhs}`"]
+#[rustc_on_unimplemented(message="no implementation for `{Self} >>= {Rhs}`",
+                         label="no implementation for `{Self} >>= {Rhs}`")]
 pub trait ShrAssign<Rhs=Self> {
     /// Performs the `>>=` operation.
     #[stable(feature = "op_assign_traits", since = "1.8.0")]