From 5c642d7d1cb56b341f76b829e507ebcd58a332c1 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Fri, 2 Dec 2022 21:01:34 +0000
Subject: [PATCH] Don't elide information when printing E0308 with Zverbose

---
 .../src/infer/error_reporting/mod.rs          |  6 +++---
 ...signature-error-reporting-under-verbose.rs | 15 +++++++++++++++
 ...ature-error-reporting-under-verbose.stderr | 19 +++++++++++++++++++
 3 files changed, 37 insertions(+), 3 deletions(-)
 create mode 100644 src/test/ui/fn/signature-error-reporting-under-verbose.rs
 create mode 100644 src/test/ui/fn/signature-error-reporting-under-verbose.stderr

diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index e2be8fb12d0d0..d62a683a15057 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -1262,7 +1262,7 @@ 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 {
+                        if ta1 == ta2 && !self.tcx.sess.verbose() {
                             values.0.push_normal("_");
                             values.1.push_normal("_");
                         } else {
@@ -1278,7 +1278,7 @@ 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 {
+                        if ca1 == ca2 && !self.tcx.sess.verbose() {
                             values.0.push_normal("_");
                             values.1.push_normal("_");
                         } else {
@@ -1457,7 +1457,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             (ty::FnPtr(sig1), ty::FnPtr(sig2)) => self.cmp_fn_sig(sig1, sig2),
 
             _ => {
-                if t1 == t2 {
+                if t1 == t2 && !self.tcx.sess.verbose() {
                     // The two types are the same, elide and don't highlight.
                     (DiagnosticStyledString::normal("_"), DiagnosticStyledString::normal("_"))
                 } else {
diff --git a/src/test/ui/fn/signature-error-reporting-under-verbose.rs b/src/test/ui/fn/signature-error-reporting-under-verbose.rs
new file mode 100644
index 0000000000000..d7a8c95e8b2ab
--- /dev/null
+++ b/src/test/ui/fn/signature-error-reporting-under-verbose.rs
@@ -0,0 +1,15 @@
+// compile-flags: -Zverbose
+
+fn foo(_: i32, _: i32) {}
+
+fn needs_ptr(_: fn(i32, u32)) {}
+//~^ NOTE function defined here
+//~| NOTE
+
+fn main() {
+    needs_ptr(foo);
+    //~^ ERROR mismatched types
+    //~| NOTE expected `u32`, found `i32`
+    //~| NOTE expected fn pointer `fn(i32, u32)`
+    //~| NOTE arguments to this function are incorrect
+}
diff --git a/src/test/ui/fn/signature-error-reporting-under-verbose.stderr b/src/test/ui/fn/signature-error-reporting-under-verbose.stderr
new file mode 100644
index 0000000000000..6260fc8dcec52
--- /dev/null
+++ b/src/test/ui/fn/signature-error-reporting-under-verbose.stderr
@@ -0,0 +1,19 @@
+error[E0308]: mismatched types
+  --> $DIR/signature-error-reporting-under-verbose.rs:10:15
+   |
+LL |     needs_ptr(foo);
+   |     --------- ^^^ expected `u32`, found `i32`
+   |     |
+   |     arguments to this function are incorrect
+   |
+   = note: expected fn pointer `fn(i32, u32)`
+                 found fn item `fn(i32, i32) {foo}`
+note: function defined here
+  --> $DIR/signature-error-reporting-under-verbose.rs:5:4
+   |
+LL | fn needs_ptr(_: fn(i32, u32)) {}
+   |    ^^^^^^^^^ ---------------
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.