Rollup merge of rust-lang#73601 - Aaron1011:fix/better-mono-overflow-…

…err, r=ecstatic-morse

Point at the call span when overflow occurs during monomorphization

This improves the output for issue rust-lang#72577, but there's still more work
to be done.

Currently, an overflow error during monomorphization results in an error
that points at the function we were unable to monomorphize. However, we
don't point at the call that caused the monomorphization to happen. In
the overflow occurs in a large recursive function, it may be difficult
to determine where the issue is.

This commit tracks and `Span` information during collection of
`MonoItem`s, which is used when emitting an overflow error. `MonoItem`
itself is unchanged, so this only affects
`src/librustc_mir/monomorphize/collector.rs`

src/test/ui/infinite/infinite-instantiation.rs

@@ -1,9 +1,3 @@
-//
-// We get an error message at the top of file (dummy span).
-// This is not helpful, but also kind of annoying to prevent,
-// so for now just live with it.
-// This test case was originally for issue #2258.
-
 // build-fail
 
 trait ToOpt: Sized {
@@ -23,11 +17,9 @@ impl<T:Clone> ToOpt for Option<T> {
 }
 
 fn function<T:ToOpt + Clone>(counter: usize, t: T) {
-//~^ ERROR reached the recursion limit while instantiating `function::<std::option::Option<
     if counter > 0 {
         function(counter - 1, t.to_option());
-        // FIXME(#4287) Error message should be here. It should be
-        // a type error to instantiate `test` at a type other than T.
+        //~^ ERROR reached the recursion limit while instantiating `function::<std::option::Option<
     }
 }
 

src/test/ui/infinite/infinite-instantiation.stderr

@@ -1,11 +1,16 @@
 error: reached the recursion limit while instantiating `function::<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<usize>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
-  --> $DIR/infinite-instantiation.rs:25:1
+  --> $DIR/infinite-instantiation.rs:21:9
+   |
+LL |         function(counter - 1, t.to_option());
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: `function` defined here
+  --> $DIR/infinite-instantiation.rs:19:1
    |
 LL | / fn function<T:ToOpt + Clone>(counter: usize, t: T) {
-LL | |
 LL | |     if counter > 0 {
 LL | |         function(counter - 1, t.to_option());
-...  |
+LL | |
 LL | |     }
 LL | | }
    | |_^

src/test/ui/issues/issue-67552.rs

@@ -18,13 +18,13 @@ fn identity<T>(x: T) -> T {
 }
 
 fn rec<T>(mut it: T)
-//~^ ERROR reached the recursion limit while instantiating
 where
     T: Iterator,
 {
     if () == () {
         T::count(it);
     } else {
         rec(identity(&mut it))
+        //~^ ERROR reached the recursion limit while instantiating
     }
 }

src/test/ui/issues/issue-67552.stderr

@@ -1,10 +1,16 @@
 error: reached the recursion limit while instantiating `rec::<&mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut &mut Empty>`
+  --> $DIR/issue-67552.rs:27:9
+   |
+LL |         rec(identity(&mut it))
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: `rec` defined here
   --> $DIR/issue-67552.rs:20:1
    |
 LL | / fn rec<T>(mut it: T)
-LL | |
 LL | | where
 LL | |     T: Iterator,
+LL | | {
 ...  |
 LL | |     }
 LL | | }

src/test/ui/issues/issue-8727.rs

@@ -3,12 +3,10 @@
 
 // build-fail
 
-fn generic<T>() {
+fn generic<T>() { //~ WARN function cannot return without recursing
     generic::<Option<T>>();
 }
-//~^^^ ERROR reached the recursion limit while instantiating `generic::<std::option::Option<
-//~| WARN function cannot return without recursing
-
+//~^^ ERROR reached the recursion limit while instantiating `generic::<std::option::Option<
 
 
 fn main () {

src/test/ui/issues/issue-8727.stderr

@@ -10,6 +10,12 @@ LL |     generic::<Option<T>>();
    = help: a `loop` may express intention better if this is on purpose
 
 error: reached the recursion limit while instantiating `generic::<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<std::option::Option<i32>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
+  --> $DIR/issue-8727.rs:7:5
+   |
+LL |     generic::<Option<T>>();
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: `generic` defined here
   --> $DIR/issue-8727.rs:6:1
    |
 LL | / fn generic<T>() {

src/test/ui/recursion/issue-38591-non-regular-dropck-recursion.stderr

@@ -1,4 +1,22 @@
 error: reached the recursion limit while instantiating `std::intrinsics::drop_in_place::<S<fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(u32))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))>> - shim(Some(S<fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(u32))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))>))`
+  --> $SRC_DIR/libcore/ptr/mod.rs:LL:COL
+   |
+LL | / pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
+LL | |     // Code here does not matter - this is replaced by the
+LL | |     // real drop glue by the compiler.
+LL | |     drop_in_place(to_drop)
+LL | | }
+   | |_^
+   |
+note: `std::intrinsics::drop_in_place` defined here
+  --> $SRC_DIR/libcore/ptr/mod.rs:LL:COL
+   |
+LL | / pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
+LL | |     // Code here does not matter - this is replaced by the
+LL | |     // real drop glue by the compiler.
+LL | |     drop_in_place(to_drop)
+LL | | }
+   | |_^
 
 error: aborting due to previous error
 

src/test/ui/recursion/recursion.rs

@@ -12,11 +12,10 @@ impl<T:Dot> Dot for Cons<T> {
     self.head * other.head + self.tail.dot(other.tail)
   }
 }
-fn test<T:Dot> (n:isize, i:isize, first:T, second:T) ->isize { //~ ERROR recursion limit
+fn test<T:Dot> (n:isize, i:isize, first:T, second:T) ->isize {
   match n {    0 => {first.dot(second)}
-      // FIXME(#4287) Error message should be here. It should be
-      // a type error to instantiate `test` at a type other than T.
     _ => {test (n-1, i+1, Cons {head:2*i+1, tail:first}, Cons{head:i*i, tail:second})}
+    //~^ ERROR recursion limit
   }
 }
 pub fn main() {

src/test/ui/recursion/recursion.stderr

@@ -1,11 +1,16 @@
 error: reached the recursion limit while instantiating `test::<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Cons<Nil>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
+  --> $DIR/recursion.rs:17:11
+   |
+LL |     _ => {test (n-1, i+1, Cons {head:2*i+1, tail:first}, Cons{head:i*i, tail:second})}
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: `test` defined here
   --> $DIR/recursion.rs:15:1
    |
 LL | / fn test<T:Dot> (n:isize, i:isize, first:T, second:T) ->isize {
 LL | |   match n {    0 => {first.dot(second)}
-LL | |       // FIXME(#4287) Error message should be here. It should be
-LL | |       // a type error to instantiate `test` at a type other than T.
 LL | |     _ => {test (n-1, i+1, Cons {head:2*i+1, tail:first}, Cons{head:i*i, tail:second})}
+LL | |
 LL | |   }
 LL | | }
    | |_^