From e7d7615105332f269a27cbd7273029377a96ccdf Mon Sep 17 00:00:00 2001
From: Dan Aloni <alonid@gmail.com>
Date: Thu, 3 Sep 2020 14:33:55 +0300
Subject: [PATCH] rustc_lint: avoid trimmed paths for ty_find_init_error

---
 compiler/rustc_lint/src/builtin.rs           |  5 ++++-
 src/test/ui/lint/uninitialized-zeroed.stderr | 10 +++++-----
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index ea624b9ed30..2b14d09671e 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -40,6 +40,7 @@ use rustc_hir::{ForeignItemKind, GenericParamKind, PatKind};
 use rustc_hir::{HirId, HirIdSet, Node};
 use rustc_index::vec::Idx;
 use rustc_middle::lint::LintDiagnosticBuilder;
+use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::subst::{GenericArgKind, Subst};
 use rustc_middle::ty::{self, layout::LayoutError, Ty, TyCtxt};
 use rustc_session::lint::FutureIncompatibleInfo;
@@ -2040,7 +2041,9 @@ impl<'tcx> LateLintPass<'tcx> for InvalidValue {
             // using zeroed or uninitialized memory.
             // We are extremely conservative with what we warn about.
             let conjured_ty = cx.typeck_results().expr_ty(expr);
-            if let Some((msg, span)) = ty_find_init_error(cx.tcx, conjured_ty, init) {
+            if let Some((msg, span)) =
+                with_no_trimmed_paths(|| ty_find_init_error(cx.tcx, conjured_ty, init))
+            {
                 cx.struct_span_lint(INVALID_VALUE, expr.span, |lint| {
                     let mut err = lint.build(&format!(
                         "the type `{}` does not permit {}",
diff --git a/src/test/ui/lint/uninitialized-zeroed.stderr b/src/test/ui/lint/uninitialized-zeroed.stderr
index 715c5d0704e..de1b6c76176 100644
--- a/src/test/ui/lint/uninitialized-zeroed.stderr
+++ b/src/test/ui/lint/uninitialized-zeroed.stderr
@@ -294,7 +294,7 @@ LL |         let _val: NonNull<i32> = mem::zeroed();
    |                                  this code causes undefined behavior when executed
    |                                  help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
    |
-   = note: `NonNull<i32>` must be non-null
+   = note: `std::ptr::NonNull<i32>` must be non-null
 
 error: the type `NonNull<i32>` does not permit being left uninitialized
   --> $DIR/uninitialized-zeroed.rs:80:34
@@ -305,7 +305,7 @@ LL |         let _val: NonNull<i32> = mem::uninitialized();
    |                                  this code causes undefined behavior when executed
    |                                  help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
    |
-   = note: `NonNull<i32>` must be non-null
+   = note: `std::ptr::NonNull<i32>` must be non-null
 
 error: the type `*const dyn Send` does not permit zero-initialization
   --> $DIR/uninitialized-zeroed.rs:82:37
@@ -415,7 +415,7 @@ LL |         let _val: NonZeroU32 = mem::transmute(0);
    |                                this code causes undefined behavior when executed
    |                                help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
    |
-   = note: `NonZeroU32` must be non-null
+   = note: `std::num::NonZeroU32` must be non-null
 
 error: the type `NonNull<i32>` does not permit zero-initialization
   --> $DIR/uninitialized-zeroed.rs:104:34
@@ -426,7 +426,7 @@ LL |         let _val: NonNull<i32> = MaybeUninit::zeroed().assume_init();
    |                                  this code causes undefined behavior when executed
    |                                  help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
    |
-   = note: `NonNull<i32>` must be non-null
+   = note: `std::ptr::NonNull<i32>` must be non-null
 
 error: the type `NonNull<i32>` does not permit being left uninitialized
   --> $DIR/uninitialized-zeroed.rs:105:34
@@ -437,7 +437,7 @@ LL |         let _val: NonNull<i32> = MaybeUninit::uninit().assume_init();
    |                                  this code causes undefined behavior when executed
    |                                  help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
    |
-   = note: `NonNull<i32>` must be non-null
+   = note: `std::ptr::NonNull<i32>` must be non-null
 
 error: the type `bool` does not permit being left uninitialized
   --> $DIR/uninitialized-zeroed.rs:106:26