don't elide shared parts of types in diagnostics when --verbose is passed

this also changes some parts of lifetime printing, which previously were not gated behind `-Z verbose`

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -1206,6 +1206,23 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             s.push_highlighted(mutbl.prefix_str());
         }
 
+        fn maybe_highlight<T: Eq + ToString>(
+            t1: T,
+            t2: T,
+            (buf1, buf2): &mut (DiagnosticStyledString, DiagnosticStyledString),
+            tcx: TyCtxt<'_>,
+        ) {
+            let highlight = t1 != t2;
+            let (t1, t2) = if highlight || tcx.sess.opts.verbose {
+                (t1.to_string(), t2.to_string())
+            } else {
+                // The two types are the same, elide and don't highlight.
+                ("_".into(), "_".into())
+            };
+            buf1.push(t1, highlight);
+            buf2.push(t2, highlight);
+        }
+
         fn cmp_ty_refs<'tcx>(
             r1: ty::Region<'tcx>,
             mut1: hir::Mutability,
@@ -1302,7 +1319,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                         if lifetimes.0 != lifetimes.1 {
                             values.0.push_highlighted(l1);
                             values.1.push_highlighted(l2);
-                        } else if lifetimes.0.is_bound() {
+                        } else if lifetimes.0.is_bound() || self.tcx.sess.opts.verbose {
                             values.0.push_normal(l1);
                             values.1.push_normal(l2);
                         } else {
@@ -1323,7 +1340,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     let num_display_types = consts_offset - regions_len;
                     for (i, (ta1, ta2)) in type_arguments.take(num_display_types).enumerate() {
                         let i = i + regions_len;
-                        if ta1 == ta2 && !self.tcx.sess.verbose_internals() {
+                        if ta1 == ta2 && !self.tcx.sess.opts.verbose {
                             values.0.push_normal("_");
                             values.1.push_normal("_");
                         } else {
@@ -1337,13 +1354,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     let const_arguments = sub1.consts().zip(sub2.consts());
                     for (i, (ca1, ca2)) in const_arguments.enumerate() {
                         let i = i + consts_offset;
-                        if ca1 == ca2 && !self.tcx.sess.verbose_internals() {
+                        maybe_highlight(ca1, ca2, &mut values, self.tcx);
-                            values.0.push_normal("_");
-                            values.1.push_normal("_");
-                        } else {
-                            values.0.push_highlighted(ca1.to_string());
-                            values.1.push_highlighted(ca2.to_string());
-                        }
                         self.push_comma(&mut values.0, &mut values.1, len, i);
                     }
 
@@ -1507,16 +1518,9 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             (ty::FnPtr(sig1), ty::FnPtr(sig2)) => self.cmp_fn_sig(sig1, sig2),
 
             _ => {
-                if t1 == t2 && !self.tcx.sess.verbose_internals() {
+                let mut strs = (DiagnosticStyledString::new(), DiagnosticStyledString::new());
-                    // The two types are the same, elide and don't highlight.
+                maybe_highlight(t1, t2, &mut strs, self.tcx);
-                    (DiagnosticStyledString::normal("_"), DiagnosticStyledString::normal("_"))
+                strs
-                } else {
-                    // We couldn't find anything in common, highlight everything.
-                    (
-                        DiagnosticStyledString::highlighted(t1.to_string()),
-                        DiagnosticStyledString::highlighted(t2.to_string()),
-                    )
-                }
             }
         }
     }

compiler/rustc_session/src/config.rs

@@ -1116,6 +1116,7 @@ impl Default for Options {
             working_dir: RealFileName::LocalPath(std::env::current_dir().unwrap()),
             color: ColorConfig::Auto,
             logical_env: FxIndexMap::default(),
+            verbose: false,
         }
     }
 }
@@ -2916,6 +2917,8 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         RealFileName::LocalPath(path.into_owned())
     };
 
+    let verbose = matches.opt_present("verbose") || unstable_opts.verbose_internals;
+
     Options {
         assert_incr_state,
         crate_types,
@@ -2957,6 +2960,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         working_dir,
         color,
         logical_env,
+        verbose,
     }
 }
 

compiler/rustc_session/src/options.rs

@@ -223,6 +223,8 @@ top_level_options!(
         /// The (potentially remapped) working directory
         working_dir: RealFileName [TRACKED],
         color: ColorConfig [UNTRACKED],
+
+        verbose: bool [UNTRACKED],
     }
 );
 

tests/mir-opt/nll/named_lifetimes_basic.rs

@@ -5,7 +5,7 @@
 // between R0 and R1 properly.
 
 // compile-flags: -Zverbose-internals
-//                ^^^^^^^^^ force compiler to dump more region information
+//                ^^^^^^^^^^^^^^^^^^^ force compiler to dump more region information
 
 #![allow(warnings)]
 

tests/mir-opt/nll/region_subtyping_basic.rs

@@ -4,7 +4,7 @@
 // including) the call to `use_x`. The `else` branch is not included.
 
 // compile-flags:-Zverbose-internals
-//               ^^^^^^^^^ force compiler to dump more region information
+//                ^^^^^^^^^^^^^^^^^^^ force compiler to dump more region information
 
 #![allow(warnings)]
 

tests/ui/type/verbose.normal.stderr

@@ -0,0 +1,14 @@
+error[E0308]: mismatched types
+  --> $DIR/verbose.rs:7:28
+   |
+LL |     let _: Foo<u32, i32> = Foo::<i32, i32> { x: 0, y: 0 };
+   |            -------------   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Foo<u32, i32>`, found `Foo<i32, i32>`
+   |            |
+   |            expected due to this
+   |
+   = note: expected struct `Foo<u32, _>`
+              found struct `Foo<i32, _>`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0308`.

tests/ui/type/verbose.rs

@@ -0,0 +1,13 @@
+// revisions:verbose normal
+// [verbose]compile-flags:--verbose
+#![crate_type = "lib"]
+
+struct Foo<T, U> { x: T, y: U }
+fn bar() {
+    let _: Foo<u32, i32> = Foo::<i32, i32> { x: 0, y: 0 };
+    //~^ ERROR mismatched types
+    //[verbose]~| NOTE expected struct `Foo<u32, i32>`
+    //[normal]~| NOTE expected struct `Foo<u32, _>`
+    //~| NOTE expected `Foo<u32, i32>`
+    //~| NOTE expected due to this
+}

tests/ui/type/verbose.verbose.stderr

@@ -0,0 +1,14 @@
+error[E0308]: mismatched types
+  --> $DIR/verbose.rs:7:28
+   |
+LL |     let _: Foo<u32, i32> = Foo::<i32, i32> { x: 0, y: 0 };
+   |            -------------   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Foo<u32, i32>`, found `Foo<i32, i32>`
+   |            |
+   |            expected due to this
+   |
+   = note: expected struct `Foo<u32, i32>`
+              found struct `Foo<i32, i32>`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0308`.