Rollup merge of #53407 - pnkfelix:partial-53351-make-more-ported-compile-fail-tests-more-robust-wrt-nll, r=nikomatsakis

make more ported compile fail tests more robust w.r.t. NLL

This is similar to PR #53369, except it covers a disjoint (and much smaller) set of tests that I needed to look at more carefully before being 100% certain they were the same kind of issue.

src/test/ui/borrowck/borrowck-closures-two-mut-fail.nll.stderr

@@ -0,0 +1,75 @@
+error[E0499]: cannot borrow `x` as mutable more than once at a time
+  --> $DIR/borrowck-closures-two-mut-fail.rs:26:24
+   |
+LL |     let c1 = to_fn_mut(|| x = 4);
+   |                        -- - first borrow occurs due to use of `x` in closure
+   |                        |
+   |                        first mutable borrow occurs here
+LL |     let c2 = to_fn_mut(|| x = 5); //~ ERROR cannot borrow `x` as mutable more than once
+   |                        ^^ - second borrow occurs due to use of `x` in closure
+   |                        |
+   |                        second mutable borrow occurs here
+LL |     c1;
+   |     -- borrow later used here
+
+error[E0499]: cannot borrow `x` as mutable more than once at a time
+  --> $DIR/borrowck-closures-two-mut-fail.rs:37:24
+   |
+LL |     let c1 = to_fn_mut(|| set(&mut x));
+   |                        --          - first borrow occurs due to use of `x` in closure
+   |                        |
+   |                        first mutable borrow occurs here
+LL |     let c2 = to_fn_mut(|| set(&mut x)); //~ ERROR cannot borrow `x` as mutable more than once
+   |                        ^^          - second borrow occurs due to use of `x` in closure
+   |                        |
+   |                        second mutable borrow occurs here
+LL |     c1;
+   |     -- borrow later used here
+
+error[E0499]: cannot borrow `x` as mutable more than once at a time
+  --> $DIR/borrowck-closures-two-mut-fail.rs:44:24
+   |
+LL |     let c1 = to_fn_mut(|| x = 5);
+   |                        -- - first borrow occurs due to use of `x` in closure
+   |                        |
+   |                        first mutable borrow occurs here
+LL |     let c2 = to_fn_mut(|| set(&mut x)); //~ ERROR cannot borrow `x` as mutable more than once
+   |                        ^^          - second borrow occurs due to use of `x` in closure
+   |                        |
+   |                        second mutable borrow occurs here
+LL |     c1;
+   |     -- borrow later used here
+
+error[E0499]: cannot borrow `x` as mutable more than once at a time
+  --> $DIR/borrowck-closures-two-mut-fail.rs:51:24
+   |
+LL |     let c1 = to_fn_mut(|| x = 5);
+   |                        -- - first borrow occurs due to use of `x` in closure
+   |                        |
+   |                        first mutable borrow occurs here
+LL |     let c2 = to_fn_mut(|| { let _y = to_fn_mut(|| set(&mut x)); }); // (nested closure)
+   |                        ^^                                  - second borrow occurs due to use of `x` in closure
+   |                        |
+   |                        second mutable borrow occurs here
+LL |     //~^ ERROR cannot borrow `x` as mutable more than once
+LL |     c1;
+   |     -- borrow later used here
+
+error[E0499]: cannot borrow `x` as mutable more than once at a time
+  --> $DIR/borrowck-closures-two-mut-fail.rs:63:24
+   |
+LL |     let c1 = to_fn_mut(|| set(&mut *x.f));
+   |                        --           - first borrow occurs due to use of `x` in closure
+   |                        |
+   |                        first mutable borrow occurs here
+LL |     let c2 = to_fn_mut(|| set(&mut *x.f));
+   |                        ^^           - second borrow occurs due to use of `x` in closure
+   |                        |
+   |                        second mutable borrow occurs here
+LL |     //~^ ERROR cannot borrow `x` as mutable more than once
+LL |     c1;
+   |     -- borrow later used here
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0499`.

src/test/ui/borrowck/borrowck-closures-two-mut-fail.rs

@@ -8,22 +8,23 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// ignore-compare-mode-nll
-
 // Tests that two closures cannot simultaneously have mutable
 // access to the variable, whether that mutable access be used
 // for direct assignment or for taking mutable ref. Issue #6801.
 
-// ignore-compare-mode-nll
-
 #![feature(box_syntax)]
 
+
+
+
+
 fn to_fn_mut<F: FnMut()>(f: F) -> F { f }
 
 fn a() {
     let mut x = 3;
     let c1 = to_fn_mut(|| x = 4);
     let c2 = to_fn_mut(|| x = 5); //~ ERROR cannot borrow `x` as mutable more than once
+    c1;
 }
 
 fn set(x: &mut isize) {
@@ -34,12 +35,14 @@ fn b() {
     let mut x = 3;
     let c1 = to_fn_mut(|| set(&mut x));
     let c2 = to_fn_mut(|| set(&mut x)); //~ ERROR cannot borrow `x` as mutable more than once
+    c1;
 }
 
 fn c() {
     let mut x = 3;
     let c1 = to_fn_mut(|| x = 5);
     let c2 = to_fn_mut(|| set(&mut x)); //~ ERROR cannot borrow `x` as mutable more than once
+    c1;
 }
 
 fn d() {
@@ -47,6 +50,7 @@ fn d() {
     let c1 = to_fn_mut(|| x = 5);
     let c2 = to_fn_mut(|| { let _y = to_fn_mut(|| set(&mut x)); }); // (nested closure)
     //~^ ERROR cannot borrow `x` as mutable more than once
+    c1;
 }
 
 fn g() {
@@ -58,6 +62,7 @@ fn g() {
     let c1 = to_fn_mut(|| set(&mut *x.f));
     let c2 = to_fn_mut(|| set(&mut *x.f));
     //~^ ERROR cannot borrow `x` as mutable more than once
+    c1;
 }
 
 fn main() {

src/test/ui/borrowck/borrowck-closures-two-mut-fail.stderr

@@ -9,11 +9,12 @@ LL |     let c2 = to_fn_mut(|| x = 5); //~ ERROR cannot borrow `x` as mutable mo
    |                        ^^ - borrow occurs due to use of `x` in closure
    |                        |
    |                        second mutable borrow occurs here
+LL |     c1;
 LL | }
    | - first borrow ends here
 
 error[E0499]: cannot borrow `x` as mutable more than once at a time
-  --> $DIR/borrowck-closures-two-mut-fail.rs:36:24
+  --> $DIR/borrowck-closures-two-mut-fail.rs:37:24
    |
 LL |     let c1 = to_fn_mut(|| set(&mut x));
    |                        --          - previous borrow occurs due to use of `x` in closure
@@ -23,11 +24,12 @@ LL |     let c2 = to_fn_mut(|| set(&mut x)); //~ ERROR cannot borrow `x` as muta
    |                        ^^          - borrow occurs due to use of `x` in closure
    |                        |
    |                        second mutable borrow occurs here
+LL |     c1;
 LL | }
    | - first borrow ends here
 
 error[E0499]: cannot borrow `x` as mutable more than once at a time
-  --> $DIR/borrowck-closures-two-mut-fail.rs:42:24
+  --> $DIR/borrowck-closures-two-mut-fail.rs:44:24
    |
 LL |     let c1 = to_fn_mut(|| x = 5);
    |                        -- - previous borrow occurs due to use of `x` in closure
@@ -37,11 +39,12 @@ LL |     let c2 = to_fn_mut(|| set(&mut x)); //~ ERROR cannot borrow `x` as muta
    |                        ^^          - borrow occurs due to use of `x` in closure
    |                        |
    |                        second mutable borrow occurs here
+LL |     c1;
 LL | }
    | - first borrow ends here
 
 error[E0499]: cannot borrow `x` as mutable more than once at a time
-  --> $DIR/borrowck-closures-two-mut-fail.rs:48:24
+  --> $DIR/borrowck-closures-two-mut-fail.rs:51:24
    |
 LL |     let c1 = to_fn_mut(|| x = 5);
    |                        -- - previous borrow occurs due to use of `x` in closure
@@ -51,12 +54,12 @@ LL |     let c2 = to_fn_mut(|| { let _y = to_fn_mut(|| set(&mut x)); }); // (nes
    |                        ^^                                  - borrow occurs due to use of `x` in closure
    |                        |
    |                        second mutable borrow occurs here
-LL |     //~^ ERROR cannot borrow `x` as mutable more than once
+...
 LL | }
    | - first borrow ends here
 
 error[E0499]: cannot borrow `x` as mutable more than once at a time
-  --> $DIR/borrowck-closures-two-mut-fail.rs:59:24
+  --> $DIR/borrowck-closures-two-mut-fail.rs:63:24
    |
 LL |     let c1 = to_fn_mut(|| set(&mut *x.f));
    |                        --           - previous borrow occurs due to use of `x` in closure
@@ -66,7 +69,7 @@ LL |     let c2 = to_fn_mut(|| set(&mut *x.f));
    |                        ^^           - borrow occurs due to use of `x` in closure
    |                        |
    |                        second mutable borrow occurs here
-LL |     //~^ ERROR cannot borrow `x` as mutable more than once
+...
 LL | }
    | - first borrow ends here
 

src/test/ui/borrowck/borrowck-closures-unique.nll.stderr

@@ -0,0 +1,54 @@
+error[E0500]: closure requires unique access to `x` but it is already borrowed
+  --> $DIR/borrowck-closures-unique.rs:36:14
+   |
+LL |     let c1 = || get(x);
+   |              --     - first borrow occurs due to use of `x` in closure
+   |              |
+   |              borrow occurs here
+LL |     let c2 = || set(x); //~ ERROR closure requires unique access to `x`
+   |              ^^     - second borrow occurs due to use of `x` in closure
+   |              |
+   |              closure construction occurs here
+LL |     c1;
+   |     -- borrow later used here
+
+error[E0500]: closure requires unique access to `x` but it is already borrowed
+  --> $DIR/borrowck-closures-unique.rs:42:14
+   |
+LL |     let c1 = || get(x);
+   |              --     - first borrow occurs due to use of `x` in closure
+   |              |
+   |              borrow occurs here
+LL |     let c2 = || { get(x); set(x); }; //~ ERROR closure requires unique access to `x`
+   |              ^^       - second borrow occurs due to use of `x` in closure
+   |              |
+   |              closure construction occurs here
+LL |     c1;
+   |     -- borrow later used here
+
+error[E0524]: two closures require unique access to `x` at the same time
+  --> $DIR/borrowck-closures-unique.rs:48:14
+   |
+LL |     let c1 = || set(x);
+   |              --     - first borrow occurs due to use of `x` in closure
+   |              |
+   |              first closure is constructed here
+LL |     let c2 = || set(x); //~ ERROR two closures require unique access to `x` at the same time
+   |              ^^     - second borrow occurs due to use of `x` in closure
+   |              |
+   |              second closure is constructed here
+LL |     c1;
+   |     -- borrow later used here
+
+error[E0594]: cannot assign to `x`, as it is not declared as mutable
+  --> $DIR/borrowck-closures-unique.rs:57:38
+   |
+LL | fn e(x: &'static mut isize) {
+   |      - help: consider changing this to be mutable: `mut x`
+LL |     let c1 = |y: &'static mut isize| x = y; //~ ERROR closure cannot assign to immutable argument
+   |                                      ^^^^^ cannot assign
+
+error: aborting due to 4 previous errors
+
+Some errors occurred: E0500, E0524, E0594.
+For more information about an error, try `rustc --explain E0500`.

src/test/ui/borrowck/borrowck-closures-unique.rs

@@ -8,14 +8,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// ignore-compare-mode-nll
-
 // Tests that a closure which requires mutable access to the referent
 // of an `&mut` requires a "unique" borrow -- that is, the variable to
 // be borrowed (here, `x`) will not be borrowed *mutably*, but
 //  may be *immutable*, but we cannot allow
 // multiple borrows.
 
+
+
 fn get(x: &isize) -> isize {
     *x
 }
@@ -27,25 +27,40 @@ fn set(x: &mut isize) -> isize {
 fn a(x: &mut isize) {
     let c1 = || get(x);
     let c2 = || get(x);
+    c1();
+    c2();
 }
 
 fn b(x: &mut isize) {
     let c1 = || get(x);
     let c2 = || set(x); //~ ERROR closure requires unique access to `x`
+    c1;
 }
 
 fn c(x: &mut isize) {
     let c1 = || get(x);
     let c2 = || { get(x); set(x); }; //~ ERROR closure requires unique access to `x`
+    c1;
 }
 
 fn d(x: &mut isize) {
     let c1 = || set(x);
     let c2 = || set(x); //~ ERROR two closures require unique access to `x` at the same time
+    c1;
 }
 
-fn e(x: &mut isize) {
+// This test was originally encoded in the form shown as `fn f` below.
+// However, since MIR-borrowck and thus NLL takes more control-flow information
+// into account, it was necessary to change the test in order to witness the
+// same (expected) error under both AST-borrowck and NLL.
+fn e(x: &'static mut isize) {
+    let c1 = |y: &'static mut isize| x = y; //~ ERROR closure cannot assign to immutable argument
+    c1;
+}
+
+fn f(x: &'static mut isize) {
     let c1 = || x = panic!(); //~ ERROR closure cannot assign to immutable argument
+    c1;
 }
 
 fn main() {

src/test/ui/borrowck/borrowck-closures-unique.stderr

@@ -1,5 +1,5 @@
 error[E0500]: closure requires unique access to `x` but it is already borrowed
-  --> $DIR/borrowck-closures-unique.rs:34:14
+  --> $DIR/borrowck-closures-unique.rs:36:14
    |
 LL |     let c1 = || get(x);
    |              --     - previous borrow occurs due to use of `x` in closure
@@ -9,11 +9,12 @@ LL |     let c2 = || set(x); //~ ERROR closure requires unique access to `x`
    |              ^^     - borrow occurs due to use of `x` in closure
    |              |
    |              closure construction occurs here
+LL |     c1;
 LL | }
    | - borrow ends here
 
 error[E0500]: closure requires unique access to `x` but it is already borrowed
-  --> $DIR/borrowck-closures-unique.rs:39:14
+  --> $DIR/borrowck-closures-unique.rs:42:14
    |
 LL |     let c1 = || get(x);
    |              --     - previous borrow occurs due to use of `x` in closure
@@ -23,11 +24,12 @@ LL |     let c2 = || { get(x); set(x); }; //~ ERROR closure requires unique acce
    |              ^^       - borrow occurs due to use of `x` in closure
    |              |
    |              closure construction occurs here
+LL |     c1;
 LL | }
    | - borrow ends here
 
 error[E0524]: two closures require unique access to `x` at the same time
-  --> $DIR/borrowck-closures-unique.rs:44:14
+  --> $DIR/borrowck-closures-unique.rs:48:14
    |
 LL |     let c1 = || set(x);
    |              --     - previous borrow occurs due to use of `x` in closure
@@ -37,11 +39,22 @@ LL |     let c2 = || set(x); //~ ERROR two closures require unique access to `x`
    |              ^^     - borrow occurs due to use of `x` in closure
    |              |
    |              second closure is constructed here
+LL |     c1;
 LL | }
    | - borrow from first closure ends here
 
 error[E0595]: closure cannot assign to immutable argument `x`
-  --> $DIR/borrowck-closures-unique.rs:48:14
+  --> $DIR/borrowck-closures-unique.rs:57:14
+   |
+LL |     let c1 = |y: &'static mut isize| x = y; //~ ERROR closure cannot assign to immutable argument
+   |              ^^^^^^^^^^^^^^^^^^^^^^^ cannot borrow mutably
+help: consider removing the `&mut`, as it is an immutable binding to a mutable reference
+   |
+LL |     x //~ ERROR closure cannot assign to immutable argument
+   |     ^
+
+error[E0595]: closure cannot assign to immutable argument `x`
+  --> $DIR/borrowck-closures-unique.rs:62:14
    |
 LL |     let c1 = || x = panic!(); //~ ERROR closure cannot assign to immutable argument
    |              ^^ cannot borrow mutably
@@ -50,7 +63,7 @@ help: consider removing the `&mut`, as it is an immutable binding to a mutable r
 LL |     x //~ ERROR closure cannot assign to immutable argument
    |     ^
 
-error: aborting due to 4 previous errors
+error: aborting due to 5 previous errors
 
 Some errors occurred: E0500, E0524, E0595.
 For more information about an error, try `rustc --explain E0500`.

src/test/ui/hashmap-lifetimes.nll.stderr

@@ -0,0 +1,13 @@
+error[E0502]: cannot borrow `my_stuff` as mutable because it is also borrowed as immutable
+  --> $DIR/hashmap-lifetimes.rs:18:5
+   |
+LL |     let mut it = my_stuff.iter();
+   |                  -------- immutable borrow occurs here
+LL |     my_stuff.insert(1, 43); //~ ERROR cannot borrow
+   |     ^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
+LL |     it;
+   |     -- borrow later used here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0502`.

src/test/ui/hashmap-lifetimes.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// ignore-compare-mode-nll
+
 
 fn main() {
     let mut my_stuff = std::collections::HashMap::new();
@@ -16,4 +16,5 @@ fn main() {
 
     let mut it = my_stuff.iter();
     my_stuff.insert(1, 43); //~ ERROR cannot borrow
+    it;
 }

src/test/ui/hashmap-lifetimes.stderr

@@ -5,6 +5,7 @@ LL |     let mut it = my_stuff.iter();
    |                  -------- immutable borrow occurs here
 LL |     my_stuff.insert(1, 43); //~ ERROR cannot borrow
    |     ^^^^^^^^ mutable borrow occurs here
+LL |     it;
 LL | }
    | - immutable borrow ends here
 

src/test/ui/unboxed-closures/unboxed-closure-region.nll.stderr

@@ -0,0 +1,15 @@
+error[E0597]: `x` does not live long enough
+  --> $DIR/unboxed-closure-region.rs:18:12
+   |
+LL |         || x //~ ERROR `x` does not live long enough
+   |         -- ^ borrowed value does not live long enough
+   |         |
+   |         value captured here
+LL |     };
+   |     - `x` dropped here while still borrowed
+LL |     _f;
+   |     -- borrow later used here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0597`.

src/test/ui/unboxed-closures/unboxed-closure-region.rs

@@ -8,13 +8,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// ignore-compare-mode-nll
-
 // Test that an unboxed closure that captures a free variable by
 // reference cannot escape the region of that variable.
+
+
 fn main() {
     let _f = {
         let x = 0;
         || x //~ ERROR `x` does not live long enough
     };
+    _f;
 }

src/test/ui/unboxed-closures/unboxed-closure-region.stderr

@@ -7,6 +7,7 @@ LL |         || x //~ ERROR `x` does not live long enough
    |         capture occurs here
 LL |     };
    |     - borrowed value only lives until here
+LL |     _f;
 LL | }
    | - borrowed value needs to live until here
 

src/test/ui/unboxed-closures/unboxed-closures-borrow-conflict.nll.stderr

@@ -0,0 +1,15 @@
+error[E0503]: cannot use `x` because it was mutably borrowed
+  --> $DIR/unboxed-closures-borrow-conflict.rs:19:14
+   |
+LL |     let f = || x += 1;
+   |             -- - borrow occurs due to use of `x` in closure
+   |             |
+   |             borrow of `x` occurs here
+LL |     let _y = x; //~ ERROR cannot use `x` because it was mutably borrowed
+   |              ^ use of borrowed `x`
+LL |     f;
+   |     - borrow later used here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0503`.

src/test/ui/unboxed-closures/unboxed-closures-borrow-conflict.rs

@@ -8,13 +8,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// ignore-compare-mode-nll
-
 // Test that an unboxed closure that mutates a free variable will
 // cause borrow conflicts.
 
+
+
 fn main() {
     let mut x = 0;
     let f = || x += 1;
     let _y = x; //~ ERROR cannot use `x` because it was mutably borrowed
+    f;
 }