Unrolled build for #152907

Rollup merge of #152907 - aerooneqq:delegation-generics-new-tests, r=petrochenkov

Add tests for delegation generics

This PR adds tests from #151864 as discussed in this [comment](#151864 (comment)). Part of #118212.

The majority of new tests are added in `mapping` folder, (`ast-hir-engine` folder in #151864), those tests test mapping between generic params of delegee and our generated function for delegation (that is why the name of the folder was changed, I think it better reflects what those tests testing). In each mapping test comments were added to each test case and one comment describing the goal of mapping tests was added at the top of each file.

Next, tests for defaults in generic params (`generic-params-defaults.rs`), params with the same name (`generic-params-same-names`), errors in providing user-specified generic args (`generics-gen-args-errors.rs`) and wrong signature of a generated function in impl trait case (`impl-trait-wrong-args-count.rs`, renamed from `wrong-args-count-ice.rs` in #151864). `generic-aux-pass.rs` test was not added, as all reuses in this test produce known ICE `DefId::expect_local DefId(..) isn't local` #143498 (which will be fixed in #151864, however it will not close mentioned issue, as synthetic generic params are not yet supported in new generics implementation).

r? @petrochenkov

Author: rust-timer

tests/ui/delegation/generics/generic-params-defaults.rs

@@ -0,0 +1,14 @@
+#![feature(fn_delegation)]
+#![allow(incomplete_features)]
+
+trait Trait<'a, 'b, 'c, A = usize, B = u32, C = String, const N: usize = 123> {
+    fn foo<T = usize>(&self) {
+        //~^ ERROR: defaults for generic parameters are not allowed here
+        //~| WARN: this was previously accepted by the compiler but is being phased out
+    }
+}
+
+reuse Trait::foo;
+//~^ ERROR: type annotations needed
+
+fn main() {}

tests/ui/delegation/generics/generic-params-defaults.stderr

@@ -0,0 +1,35 @@
+error: defaults for generic parameters are not allowed here
+  --> $DIR/generic-params-defaults.rs:5:12
+   |
+LL |     fn foo<T = usize>(&self) {
+   |            ^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #36887 <https://github.com/rust-lang/rust/issues/36887>
+   = note: `#[deny(invalid_type_param_default)]` (part of `#[deny(future_incompatible)]`) on by default
+
+error[E0282]: type annotations needed
+  --> $DIR/generic-params-defaults.rs:11:14
+   |
+LL | reuse Trait::foo;
+   |              ^^^ cannot infer type of the type parameter `T` declared on the method `foo`
+   |
+help: consider specifying the generic argument
+   |
+LL | reuse Trait::foo::<T>;
+   |                 +++++
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0282`.
+Future incompatibility report: Future breakage diagnostic:
+error: defaults for generic parameters are not allowed here
+  --> $DIR/generic-params-defaults.rs:5:12
+   |
+LL |     fn foo<T = usize>(&self) {
+   |            ^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #36887 <https://github.com/rust-lang/rust/issues/36887>
+   = note: `#[deny(invalid_type_param_default)]` (part of `#[deny(future_incompatible)]`) on by default
+

tests/ui/delegation/generics/generic-params-same-names.rs

@@ -0,0 +1,19 @@
+#![feature(fn_delegation)]
+#![allow(incomplete_features)]
+
+trait Trait<'a, 'b, 'c, A, B, C, const N: usize> {
+    fn foo<'a, 'b, 'c, A, B, C, const N: usize>(&self) {
+        //~^ ERROR: lifetime name `'a` shadows a lifetime name that is already in scope
+        //~| ERROR: lifetime name `'b` shadows a lifetime name that is already in scope
+        //~| ERROR: lifetime name `'c` shadows a lifetime name that is already in scope
+        //~| ERROR: the name `A` is already used for a generic parameter in this item's generic parameters
+        //~| ERROR: the name `B` is already used for a generic parameter in this item's generic parameters
+        //~| ERROR: the name `C` is already used for a generic parameter in this item's generic parameters
+        //~| ERROR: the name `N` is already used for a generic parameter in this item's generic parameters
+    }
+}
+
+reuse Trait::foo;
+//~^ ERROR: type annotations needed
+
+fn main() {}

tests/ui/delegation/generics/generic-params-same-names.stderr

@@ -0,0 +1,76 @@
+error[E0496]: lifetime name `'a` shadows a lifetime name that is already in scope
+  --> $DIR/generic-params-same-names.rs:5:12
+   |
+LL | trait Trait<'a, 'b, 'c, A, B, C, const N: usize> {
+   |             -- first declared here
+LL |     fn foo<'a, 'b, 'c, A, B, C, const N: usize>(&self) {
+   |            ^^ lifetime `'a` already in scope
+
+error[E0496]: lifetime name `'b` shadows a lifetime name that is already in scope
+  --> $DIR/generic-params-same-names.rs:5:16
+   |
+LL | trait Trait<'a, 'b, 'c, A, B, C, const N: usize> {
+   |                 -- first declared here
+LL |     fn foo<'a, 'b, 'c, A, B, C, const N: usize>(&self) {
+   |                ^^ lifetime `'b` already in scope
+
+error[E0496]: lifetime name `'c` shadows a lifetime name that is already in scope
+  --> $DIR/generic-params-same-names.rs:5:20
+   |
+LL | trait Trait<'a, 'b, 'c, A, B, C, const N: usize> {
+   |                     -- first declared here
+LL |     fn foo<'a, 'b, 'c, A, B, C, const N: usize>(&self) {
+   |                    ^^ lifetime `'c` already in scope
+
+error[E0403]: the name `A` is already used for a generic parameter in this item's generic parameters
+  --> $DIR/generic-params-same-names.rs:5:24
+   |
+LL | trait Trait<'a, 'b, 'c, A, B, C, const N: usize> {
+   |                         - first use of `A`
+LL |     fn foo<'a, 'b, 'c, A, B, C, const N: usize>(&self) {
+   |                        ^ already used
+
+error[E0403]: the name `B` is already used for a generic parameter in this item's generic parameters
+  --> $DIR/generic-params-same-names.rs:5:27
+   |
+LL | trait Trait<'a, 'b, 'c, A, B, C, const N: usize> {
+   |                            - first use of `B`
+LL |     fn foo<'a, 'b, 'c, A, B, C, const N: usize>(&self) {
+   |                           ^ already used
+
+error[E0403]: the name `C` is already used for a generic parameter in this item's generic parameters
+  --> $DIR/generic-params-same-names.rs:5:30
+   |
+LL | trait Trait<'a, 'b, 'c, A, B, C, const N: usize> {
+   |                               - first use of `C`
+LL |     fn foo<'a, 'b, 'c, A, B, C, const N: usize>(&self) {
+   |                              ^ already used
+
+error[E0403]: the name `N` is already used for a generic parameter in this item's generic parameters
+  --> $DIR/generic-params-same-names.rs:5:39
+   |
+LL | trait Trait<'a, 'b, 'c, A, B, C, const N: usize> {
+   |                                        - first use of `N`
+LL |     fn foo<'a, 'b, 'c, A, B, C, const N: usize>(&self) {
+   |                                       ^ already used
+
+error[E0284]: type annotations needed
+  --> $DIR/generic-params-same-names.rs:16:14
+   |
+LL | reuse Trait::foo;
+   |              ^^^ cannot infer the value of the const parameter `N` declared on the method `foo`
+   |
+note: required by a const generic parameter in `Trait::foo`
+  --> $DIR/generic-params-same-names.rs:5:33
+   |
+LL |     fn foo<'a, 'b, 'c, A, B, C, const N: usize>(&self) {
+   |                                 ^^^^^^^^^^^^^^ required by this const generic parameter in `Trait::foo`
+help: consider specifying the generic arguments
+   |
+LL | reuse Trait::foo::<A, B, C, N>;
+   |                 ++++++++++++++
+
+error: aborting due to 8 previous errors
+
+Some errors have detailed explanations: E0284, E0403, E0496.
+For more information about an error, try `rustc --explain E0284`.

tests/ui/delegation/generics/generics-gen-args-errors.rs

@@ -0,0 +1,114 @@
+//@ compile-flags: -Z deduplicate-diagnostics=yes
+
+#![feature(fn_delegation)]
+#![allow(incomplete_features)]
+
+mod test_1 {
+    fn foo<'a: 'a, 'b: 'b, T: Clone, U: Clone, const N: usize>() {}
+    reuse foo as bar;
+    //~^ ERROR: type annotations needed
+
+    fn check<A, B, C>() {
+        bar::<1, 2, 3, 4, 5, 6>();
+        //~^ ERROR: function takes 3 generic arguments but 6 generic arguments were supplied
+
+        bar::<String, String, { String }>();
+        //~^ ERROR: expected value, found struct `String` [E0423]
+
+        bar::<'static, 'static, 'static, 'static, 'static>();
+        //~^ ERROR: function takes 2 lifetime arguments but 5 lifetime arguments were supplied
+
+        bar::<String, 1, 'static, i32, 'static>();
+        //~^ ERROR: constant provided when a type was expected
+
+        bar();
+
+        bar::<_, _, _, _, _>();
+        //~^ ERROR: function takes 3 generic arguments but 5 generic arguments were supplied
+
+        bar::<asd, asd, asd>();
+        //~^ ERROR: cannot find type `asd` in this scope
+        //~| ERROR: cannot find type `asd` in this scope
+        //~| ERROR: cannot find type `asd` in this scope
+        //~| ERROR: unresolved item provided when a constant was expected
+
+        reuse foo::<A, B, C> as xd;
+        //~^ ERROR can't use generic parameters from outer item
+        //~| ERROR can't use generic parameters from outer item
+        //~| ERROR can't use generic parameters from outer item
+        //~| ERROR: unresolved item provided when a constant was expected
+    }
+}
+
+mod test_2 {
+    fn foo<'a: 'a, 'b: 'b, T: Clone, U: Clone, const N: usize>() {}
+
+    reuse foo::<> as bar1;
+    //~^ ERROR: type annotations needed
+
+    reuse foo::<String, String> as bar2;
+    //~^ ERROR: function takes 3 generic arguments but 2 generic arguments were supplied
+
+    reuse foo::<'static, _, 'asdasd, 'static, 'static, 'static, _> as bar3;
+    //~^ ERROR: use of undeclared lifetime name `'asdasd`
+    //~| ERROR: function takes 2 lifetime arguments but 5 lifetime arguments were supplied
+    //~| ERROR: function takes 3 generic arguments but 2 generic arguments were supplied
+    reuse foo::<String, 'static, 123, asdasd> as bar4;
+    //~^ ERROR: cannot find type `asdasd` in this scope
+    //~| ERROR: function takes 2 lifetime arguments but 1 lifetime argument was supplied
+
+    reuse foo::<1, 2, _, 4, 5, _> as bar5;
+    //~^ ERROR: function takes 3 generic arguments but 6 generic arguments were supplied
+
+    reuse foo::<1, 2,asd,String, { let x = 0; }> as bar6;
+    //~^ ERROR: cannot find type `asd` in this scope
+    //~| ERROR: function takes 3 generic arguments but 5 generic arguments were supplied
+
+    reuse foo::<"asdasd", asd, "askdn", 'static, 'a> as bar7;
+    //~^ ERROR: use of undeclared lifetime name `'a`
+    //~| ERROR: cannot find type `asd` in this scope
+    //~| ERROR: constant provided when a type was expected
+
+    reuse foo::<{}, {}, {}> as bar8;
+    //~^ ERROR: constant provided when a type was expected
+}
+
+mod test_3 {
+    trait Trait<'b, 'c, 'a, T, const N: usize>: Sized {
+        fn foo<'d: 'd, U, const M: bool>(self) {}
+    }
+
+    reuse Trait::<asd, asd, asd, asd, asd, asdasa>::foo as bar1;
+    //~^ ERROR: cannot find type `asd` in this scope
+    //~| ERROR: cannot find type `asd` in this scope
+    //~| ERROR: cannot find type `asd` in this scope
+    //~| ERROR: cannot find type `asd` in this scope
+    //~| ERROR: cannot find type `asd` in this scope
+    //~| ERROR: cannot find type `asdasa` in this scope
+    //~| ERROR: trait takes 2 generic arguments but 6 generic arguments were supplied
+
+    reuse Trait::<'static, 'static>::foo as bar2;
+    //~^ ERROR: trait takes 3 lifetime arguments but 2 lifetime arguments were supplied
+    reuse Trait::<1, 2, 3, 4, 5>::foo as bar3;
+    //~^ ERROR: trait takes 2 generic arguments but 5 generic arguments were supplied
+
+    reuse Trait::<1, 2, true>::foo as bar4;
+    //~^ ERROR: trait takes 2 generic arguments but 3 generic arguments were supplied
+
+    reuse Trait::<'static>::foo as bar5;
+    //~^ ERROR: trait takes 3 lifetime arguments but 1 lifetime argument was supplied
+
+    reuse Trait::<1, 2, 'static, DDDD>::foo::<1, 2, 3, 4, 5, 6> as bar6;
+    //~^ ERROR: cannot find type `DDDD` in this scope [E0425]
+    //~| ERROR: trait takes 3 lifetime arguments but 1 lifetime argument was supplied
+    //~| ERROR: trait takes 2 generic arguments but 3 generic arguments were supplied
+    //~| ERROR: method takes 2 generic arguments but 6 generic arguments were supplied
+
+    reuse Trait::<Trait, Clone, _, 'static, dyn Send, _>::foo::<1, 2, 3, _, 6> as bar7;
+    //~^ ERROR: missing lifetime specifiers [E0106]
+    //~| ERROR: trait takes 3 lifetime arguments but 1 lifetime argument was supplied
+    //~| ERROR: trait takes 2 generic arguments but 5 generic arguments were supplied
+    //~| ERROR: method takes 2 generic arguments but 5 generic arguments were supplied
+}
+
+fn main() {}