gccrs: Subset errors with locations

gcc/rust/ChangeLog:

	* checks/errors/borrowck/rust-borrow-checker-diagnostics.cc
	(BorrowCheckerDiagnostics::report_subset_errors): Highlight
	lifetime locations while reporting subset errors.
	(BorrowCheckerDiagnostics::get_lifetime_param): Helper function
	to fetch HIR::Lifetime node from Polonius::Origin.
	* checks/errors/borrowck/rust-borrow-checker-diagnostics.h:
	Definition of helper function.

gcc/testsuite/ChangeLog:

	* rust/borrowck/subset.rs: Better subset errors.

Signed-off-by: Kushal Pal <kushalpal109@gmail.com>

1 files changed, 25 insertions, 4 deletions

diff --git a/gcc/testsuite/rust/borrowck/subset.rs b/gcc/testsuite/rust/borrowck/subset.rs
index d7c00ca..5b4a663 100644
--- a/gcc/testsuite/rust/borrowck/subset.rs
+++ b/gcc/testsuite/rust/borrowck/subset.rs
@@ -1,8 +1,19 @@
-// { dg-additional-options "-frust-compile-until=compilation -frust-borrowcheck" }
+// { dg-additional-options "-frust-compile-until=compilation -frust-borrowcheck -fdiagnostics-show-caret -fdiagnostics-show-line-numbers" }
+// { dg-enable-nn-line-numbers "" }
 
 fn missing_subset<'a, 'b>(x: &'a u32, y: &'b u32) -> &'a u32 {
-    // { dg-error "Found subset errors in function missing_subset" "" { target *-*-* } .-1 }
+    // { dg-error "subset error, some lifetime constraints need to be added" "" { target *-*-* } .-1 }
     y //~ ERROR
+    /*
+     { dg-begin-multiline-output "" }
+   NN | fn missing_subset<'a, 'b>(x: &'a u32, y: &'b u32) -> &'a u32 {
+      | ^~                ~~  ~~
+      | |                 |   |
+      | |                 |   lifetime defined here
+      | |                 lifetime defined here
+      | subset error occurs in this function
+     { dg-end-multiline-output "" }
+    */
 }
 
 fn missing_subset_fixed<'a, 'b>(x: &'a u32, y: &'b u32) -> &'a u32 where 'b: 'a {
@@ -10,12 +21,22 @@ fn missing_subset_fixed<'a, 'b>(x: &'a u32, y: &'b u32) -> &'a u32 where 'b: 'a
 }
 
 fn complex_cfg_subset<'a, 'b>(b: bool, x: &'a u32, y: &'b u32) -> &'a u32 {
-    // { dg-error "Found subset errors in function complex_cfg_subset" "" { target *-*-* } .-1 }
+    // { dg-error "subset error, some lifetime constraints need to be added" "" { target *-*-* } .-1 }
     if b {
         y //~ ERROR
     } else {
         x
     }
+    /*
+     { dg-begin-multiline-output "" }
+   NN | fn complex_cfg_subset<'a, 'b>(b: bool, x: &'a u32, y: &'b u32) -> &'a u32 {
+      | ^~                    ~~  ~~
+      | |                     |   |
+      | |                     |   lifetime defined here
+      | |                     lifetime defined here
+      | subset error occurs in this function
+     { dg-end-multiline-output "" }
+    */
 }
 
 fn complex_cfg_subset_fixed<'a, 'b>(b: bool, x: &'a u32, y: &'b u32) -> &'a u32 where 'b: 'a {
@@ -24,4 +45,4 @@ fn complex_cfg_subset_fixed<'a, 'b>(b: bool, x: &'a u32, y: &'b u32) -> &'a u32
     } else {
         y
     }
-}
\ No newline at end of file
+}