From 511804801e96d5a1c3d753c46cf6811679103151 Mon Sep 17 00:00:00 2001
From: jumbatm <jumbatm@gmail.com>
Date: Fri, 3 Apr 2020 23:48:04 +1000
Subject: [PATCH 01/10] Amend exceeding-bitshifts test case for #69021.

- Change to warnings so that all lints are emitted
- Expect build-pass
- Change placeholder FIXME to WARN.
---
 .../lint-exceeding-bitshifts.noopt.stderr     | 62 ++++++++++---------
 .../lint/lint-exceeding-bitshifts.opt.stderr  | 62 ++++++++++---------
 ...-bitshifts.opt_with_overflow_checks.stderr | 62 ++++++++++---------
 src/test/ui/lint/lint-exceeding-bitshifts.rs  | 52 ++++++++--------
 4 files changed, 125 insertions(+), 113 deletions(-)

diff --git a/src/test/ui/lint/lint-exceeding-bitshifts.noopt.stderr b/src/test/ui/lint/lint-exceeding-bitshifts.noopt.stderr
index ce9b02b6d82a7..72ff41a5902bc 100644
--- a/src/test/ui/lint/lint-exceeding-bitshifts.noopt.stderr
+++ b/src/test/ui/lint/lint-exceeding-bitshifts.noopt.stderr
@@ -1,146 +1,150 @@
-error: this arithmetic operation will overflow
-  --> $DIR/lint-exceeding-bitshifts.rs:22:13
+warning: this arithmetic operation will overflow
+  --> $DIR/lint-exceeding-bitshifts.rs:18:20
    |
-LL |     let _ = x << 42;
-   |             ^^^^^^^ attempt to shift left with overflow
+LL |     const N: i32 = T::N << 42;
+   |                    ^^^^^^^^^^ attempt to shift left with overflow
    |
 note: the lint level is defined here
   --> $DIR/lint-exceeding-bitshifts.rs:9:9
    |
-LL | #![deny(arithmetic_overflow, const_err)]
+LL | #![warn(arithmetic_overflow, const_err)]
    |         ^^^^^^^^^^^^^^^^^^^
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
+  --> $DIR/lint-exceeding-bitshifts.rs:22:13
+   |
+LL |     let _ = x << 42;
+   |             ^^^^^^^ attempt to shift left with overflow
+
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:27:15
    |
 LL |       let n = 1u8 << 8;
    |               ^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:29:15
    |
 LL |       let n = 1u16 << 16;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:31:15
    |
 LL |       let n = 1u32 << 32;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:33:15
    |
 LL |       let n = 1u64 << 64;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:35:15
    |
 LL |       let n = 1i8 << 8;
    |               ^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:37:15
    |
 LL |       let n = 1i16 << 16;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:39:15
    |
 LL |       let n = 1i32 << 32;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:41:15
    |
 LL |       let n = 1i64 << 64;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:44:15
    |
 LL |       let n = 1u8 >> 8;
    |               ^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:46:15
    |
 LL |       let n = 1u16 >> 16;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:48:15
    |
 LL |       let n = 1u32 >> 32;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:50:15
    |
 LL |       let n = 1u64 >> 64;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:52:15
    |
 LL |       let n = 1i8 >> 8;
    |               ^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:54:15
    |
 LL |       let n = 1i16 >> 16;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:56:15
    |
 LL |       let n = 1i32 >> 32;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:58:15
    |
 LL |       let n = 1i64 >> 64;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:62:15
    |
 LL |       let n = n << 8;
    |               ^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:64:15
    |
 LL |       let n = 1u8 << -8;
    |               ^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:69:15
    |
 LL |       let n = 1u8 << (4+4);
    |               ^^^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:71:15
    |
 LL |       let n = 1i64 >> [64][0];
    |               ^^^^^^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:77:15
    |
 LL |       let n = 1_isize << BITS;
    |               ^^^^^^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:78:15
    |
 LL |       let n = 1_usize << BITS;
    |               ^^^^^^^^^^^^^^^ attempt to shift left with overflow
 
-error: aborting due to 23 previous errors
-
diff --git a/src/test/ui/lint/lint-exceeding-bitshifts.opt.stderr b/src/test/ui/lint/lint-exceeding-bitshifts.opt.stderr
index ce9b02b6d82a7..72ff41a5902bc 100644
--- a/src/test/ui/lint/lint-exceeding-bitshifts.opt.stderr
+++ b/src/test/ui/lint/lint-exceeding-bitshifts.opt.stderr
@@ -1,146 +1,150 @@
-error: this arithmetic operation will overflow
-  --> $DIR/lint-exceeding-bitshifts.rs:22:13
+warning: this arithmetic operation will overflow
+  --> $DIR/lint-exceeding-bitshifts.rs:18:20
    |
-LL |     let _ = x << 42;
-   |             ^^^^^^^ attempt to shift left with overflow
+LL |     const N: i32 = T::N << 42;
+   |                    ^^^^^^^^^^ attempt to shift left with overflow
    |
 note: the lint level is defined here
   --> $DIR/lint-exceeding-bitshifts.rs:9:9
    |
-LL | #![deny(arithmetic_overflow, const_err)]
+LL | #![warn(arithmetic_overflow, const_err)]
    |         ^^^^^^^^^^^^^^^^^^^
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
+  --> $DIR/lint-exceeding-bitshifts.rs:22:13
+   |
+LL |     let _ = x << 42;
+   |             ^^^^^^^ attempt to shift left with overflow
+
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:27:15
    |
 LL |       let n = 1u8 << 8;
    |               ^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:29:15
    |
 LL |       let n = 1u16 << 16;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:31:15
    |
 LL |       let n = 1u32 << 32;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:33:15
    |
 LL |       let n = 1u64 << 64;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:35:15
    |
 LL |       let n = 1i8 << 8;
    |               ^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:37:15
    |
 LL |       let n = 1i16 << 16;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:39:15
    |
 LL |       let n = 1i32 << 32;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:41:15
    |
 LL |       let n = 1i64 << 64;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:44:15
    |
 LL |       let n = 1u8 >> 8;
    |               ^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:46:15
    |
 LL |       let n = 1u16 >> 16;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:48:15
    |
 LL |       let n = 1u32 >> 32;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:50:15
    |
 LL |       let n = 1u64 >> 64;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:52:15
    |
 LL |       let n = 1i8 >> 8;
    |               ^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:54:15
    |
 LL |       let n = 1i16 >> 16;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:56:15
    |
 LL |       let n = 1i32 >> 32;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:58:15
    |
 LL |       let n = 1i64 >> 64;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:62:15
    |
 LL |       let n = n << 8;
    |               ^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:64:15
    |
 LL |       let n = 1u8 << -8;
    |               ^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:69:15
    |
 LL |       let n = 1u8 << (4+4);
    |               ^^^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:71:15
    |
 LL |       let n = 1i64 >> [64][0];
    |               ^^^^^^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:77:15
    |
 LL |       let n = 1_isize << BITS;
    |               ^^^^^^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:78:15
    |
 LL |       let n = 1_usize << BITS;
    |               ^^^^^^^^^^^^^^^ attempt to shift left with overflow
 
-error: aborting due to 23 previous errors
-
diff --git a/src/test/ui/lint/lint-exceeding-bitshifts.opt_with_overflow_checks.stderr b/src/test/ui/lint/lint-exceeding-bitshifts.opt_with_overflow_checks.stderr
index ce9b02b6d82a7..72ff41a5902bc 100644
--- a/src/test/ui/lint/lint-exceeding-bitshifts.opt_with_overflow_checks.stderr
+++ b/src/test/ui/lint/lint-exceeding-bitshifts.opt_with_overflow_checks.stderr
@@ -1,146 +1,150 @@
-error: this arithmetic operation will overflow
-  --> $DIR/lint-exceeding-bitshifts.rs:22:13
+warning: this arithmetic operation will overflow
+  --> $DIR/lint-exceeding-bitshifts.rs:18:20
    |
-LL |     let _ = x << 42;
-   |             ^^^^^^^ attempt to shift left with overflow
+LL |     const N: i32 = T::N << 42;
+   |                    ^^^^^^^^^^ attempt to shift left with overflow
    |
 note: the lint level is defined here
   --> $DIR/lint-exceeding-bitshifts.rs:9:9
    |
-LL | #![deny(arithmetic_overflow, const_err)]
+LL | #![warn(arithmetic_overflow, const_err)]
    |         ^^^^^^^^^^^^^^^^^^^
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
+  --> $DIR/lint-exceeding-bitshifts.rs:22:13
+   |
+LL |     let _ = x << 42;
+   |             ^^^^^^^ attempt to shift left with overflow
+
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:27:15
    |
 LL |       let n = 1u8 << 8;
    |               ^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:29:15
    |
 LL |       let n = 1u16 << 16;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:31:15
    |
 LL |       let n = 1u32 << 32;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:33:15
    |
 LL |       let n = 1u64 << 64;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:35:15
    |
 LL |       let n = 1i8 << 8;
    |               ^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:37:15
    |
 LL |       let n = 1i16 << 16;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:39:15
    |
 LL |       let n = 1i32 << 32;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:41:15
    |
 LL |       let n = 1i64 << 64;
    |               ^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:44:15
    |
 LL |       let n = 1u8 >> 8;
    |               ^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:46:15
    |
 LL |       let n = 1u16 >> 16;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:48:15
    |
 LL |       let n = 1u32 >> 32;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:50:15
    |
 LL |       let n = 1u64 >> 64;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:52:15
    |
 LL |       let n = 1i8 >> 8;
    |               ^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:54:15
    |
 LL |       let n = 1i16 >> 16;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:56:15
    |
 LL |       let n = 1i32 >> 32;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:58:15
    |
 LL |       let n = 1i64 >> 64;
    |               ^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:62:15
    |
 LL |       let n = n << 8;
    |               ^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:64:15
    |
 LL |       let n = 1u8 << -8;
    |               ^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:69:15
    |
 LL |       let n = 1u8 << (4+4);
    |               ^^^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:71:15
    |
 LL |       let n = 1i64 >> [64][0];
    |               ^^^^^^^^^^^^^^^ attempt to shift right with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:77:15
    |
 LL |       let n = 1_isize << BITS;
    |               ^^^^^^^^^^^^^^^ attempt to shift left with overflow
 
-error: this arithmetic operation will overflow
+warning: this arithmetic operation will overflow
   --> $DIR/lint-exceeding-bitshifts.rs:78:15
    |
 LL |       let n = 1_usize << BITS;
    |               ^^^^^^^^^^^^^^^ attempt to shift left with overflow
 
-error: aborting due to 23 previous errors
-
diff --git a/src/test/ui/lint/lint-exceeding-bitshifts.rs b/src/test/ui/lint/lint-exceeding-bitshifts.rs
index 7deee5320a878..5d0cfd3ab7880 100644
--- a/src/test/ui/lint/lint-exceeding-bitshifts.rs
+++ b/src/test/ui/lint/lint-exceeding-bitshifts.rs
@@ -3,10 +3,10 @@
 //[opt]compile-flags: -O
 //[opt_with_overflow_checks]compile-flags: -C overflow-checks=on -O
 
-// build-fail
+// build-pass
 
 #![crate_type="lib"]
-#![deny(arithmetic_overflow, const_err)]
+#![warn(arithmetic_overflow, const_err)]
 #![allow(unused_variables)]
 #![allow(dead_code)]
 
@@ -15,65 +15,65 @@ pub trait Foo {
 }
 
 impl<T: Foo> Foo for Vec<T> {
-    const N: i32 = T::N << 42; // FIXME this should warn
+    const N: i32 = T::N << 42; //~ WARN: arithmetic operation will overflow
 }
 
 pub fn foo(x: i32) {
-    let _ = x << 42; //~ ERROR: arithmetic operation will overflow
+    let _ = x << 42; //~ WARN: arithmetic operation will overflow
 }
 
 pub fn main() {
       let n = 1u8 << 7;
-      let n = 1u8 << 8;   //~ ERROR: arithmetic operation will overflow
+      let n = 1u8 << 8;   //~ WARN: arithmetic operation will overflow
       let n = 1u16 << 15;
-      let n = 1u16 << 16; //~ ERROR: arithmetic operation will overflow
+      let n = 1u16 << 16; //~ WARN: arithmetic operation will overflow
       let n = 1u32 << 31;
-      let n = 1u32 << 32; //~ ERROR: arithmetic operation will overflow
+      let n = 1u32 << 32; //~ WARN: arithmetic operation will overflow
       let n = 1u64 << 63;
-      let n = 1u64 << 64; //~ ERROR: arithmetic operation will overflow
+      let n = 1u64 << 64; //~ WARN: arithmetic operation will overflow
       let n = 1i8 << 7;
-      let n = 1i8 << 8;   //~ ERROR: arithmetic operation will overflow
+      let n = 1i8 << 8;   //~ WARN: arithmetic operation will overflow
       let n = 1i16 << 15;
-      let n = 1i16 << 16; //~ ERROR: arithmetic operation will overflow
+      let n = 1i16 << 16; //~ WARN: arithmetic operation will overflow
       let n = 1i32 << 31;
-      let n = 1i32 << 32; //~ ERROR: arithmetic operation will overflow
+      let n = 1i32 << 32; //~ WARN: arithmetic operation will overflow
       let n = 1i64 << 63;
-      let n = 1i64 << 64; //~ ERROR: arithmetic operation will overflow
+      let n = 1i64 << 64; //~ WARN: arithmetic operation will overflow
 
       let n = 1u8 >> 7;
-      let n = 1u8 >> 8;   //~ ERROR: arithmetic operation will overflow
+      let n = 1u8 >> 8;   //~ WARN: arithmetic operation will overflow
       let n = 1u16 >> 15;
-      let n = 1u16 >> 16; //~ ERROR: arithmetic operation will overflow
+      let n = 1u16 >> 16; //~ WARN: arithmetic operation will overflow
       let n = 1u32 >> 31;
-      let n = 1u32 >> 32; //~ ERROR: arithmetic operation will overflow
+      let n = 1u32 >> 32; //~ WARN: arithmetic operation will overflow
       let n = 1u64 >> 63;
-      let n = 1u64 >> 64; //~ ERROR: arithmetic operation will overflow
+      let n = 1u64 >> 64; //~ WARN: arithmetic operation will overflow
       let n = 1i8 >> 7;
-      let n = 1i8 >> 8;   //~ ERROR: arithmetic operation will overflow
+      let n = 1i8 >> 8;   //~ WARN: arithmetic operation will overflow
       let n = 1i16 >> 15;
-      let n = 1i16 >> 16; //~ ERROR: arithmetic operation will overflow
+      let n = 1i16 >> 16; //~ WARN: arithmetic operation will overflow
       let n = 1i32 >> 31;
-      let n = 1i32 >> 32; //~ ERROR: arithmetic operation will overflow
+      let n = 1i32 >> 32; //~ WARN: arithmetic operation will overflow
       let n = 1i64 >> 63;
-      let n = 1i64 >> 64; //~ ERROR: arithmetic operation will overflow
+      let n = 1i64 >> 64; //~ WARN: arithmetic operation will overflow
 
       let n = 1u8;
       let n = n << 7;
-      let n = n << 8; //~ ERROR: arithmetic operation will overflow
+      let n = n << 8; //~ WARN: arithmetic operation will overflow
 
-      let n = 1u8 << -8; //~ ERROR: arithmetic operation will overflow
+      let n = 1u8 << -8; //~ WARN: arithmetic operation will overflow
 
       let n = 1i8<<(1isize+-1);
 
       let n = 1u8 << (4+3);
-      let n = 1u8 << (4+4); //~ ERROR: arithmetic operation will overflow
+      let n = 1u8 << (4+4); //~ WARN: arithmetic operation will overflow
       let n = 1i64 >> [63][0];
-      let n = 1i64 >> [64][0]; //~ ERROR: arithmetic operation will overflow
+      let n = 1i64 >> [64][0]; //~ WARN: arithmetic operation will overflow
 
       #[cfg(target_pointer_width = "32")]
       const BITS: usize = 32;
       #[cfg(target_pointer_width = "64")]
       const BITS: usize = 64;
-      let n = 1_isize << BITS; //~ ERROR: arithmetic operation will overflow
-      let n = 1_usize << BITS; //~ ERROR: arithmetic operation will overflow
+      let n = 1_isize << BITS; //~ WARN: arithmetic operation will overflow
+      let n = 1_usize << BITS; //~ WARN: arithmetic operation will overflow
 }

From a017a5b6cf57d41a9535eb88697028ead4f7eb39 Mon Sep 17 00:00:00 2001
From: jumbatm <jumbatm@gmail.com>
Date: Thu, 2 Apr 2020 04:33:39 +1000
Subject: [PATCH 02/10] Move early needs_subst bailout to _after_ linting.

This ensures we get still get lints for generic contexts.
---
 src/librustc_mir/transform/const_prop.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs
index c7f63d24c28ab..616a2056d854e 100644
--- a/src/librustc_mir/transform/const_prop.rs
+++ b/src/librustc_mir/transform/const_prop.rs
@@ -575,11 +575,6 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             return None;
         }
 
-        // FIXME we need to revisit this for #67176
-        if rvalue.needs_subst() {
-            return None;
-        }
-
         // Perform any special handling for specific Rvalue types.
         // Generally, checks here fall into one of two categories:
         //   1. Additional checking to provide useful lints to the user
@@ -620,6 +615,11 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             _ => {}
         }
 
+        // FIXME we need to revisit this for #67176
+        if rvalue.needs_subst() {
+            return None;
+        }
+
         self.use_ecx(|this| {
             trace!("calling eval_rvalue_into_place(rvalue = {:?}, place = {:?})", rvalue, place);
             this.ecx.eval_rvalue_into_place(rvalue, place)?;

From 54b5d30f2981736156e75d49e39632875dad5f73 Mon Sep 17 00:00:00 2001
From: Tom Dohrmann <erbse.13@gmx.de>
Date: Fri, 10 Apr 2020 21:15:10 +0200
Subject: [PATCH 03/10] fix target & runtool args order

---
 src/librustdoc/test.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/librustdoc/test.rs b/src/librustdoc/test.rs
index 7841d5eef58a8..fbbe172afb81f 100644
--- a/src/librustdoc/test.rs
+++ b/src/librustdoc/test.rs
@@ -263,7 +263,12 @@ fn run_test(
     if no_run && !compile_fail {
         compiler.arg("--emit=metadata");
     }
-    compiler.arg("--target").arg(target.to_string());
+    compiler.arg("--target").arg(match target {
+        TargetTriple::TargetTriple(s) => s,
+        TargetTriple::TargetPath(path) => {
+            path.to_str().expect("target path must be valid unicode").to_string()
+        }
+    });
 
     compiler.arg("-");
     compiler.stdin(Stdio::piped());
@@ -312,8 +317,8 @@ fn run_test(
 
     if let Some(tool) = runtool {
         cmd = Command::new(tool);
-        cmd.arg(output_file);
         cmd.args(runtool_args);
+        cmd.arg(output_file);
     } else {
         cmd = Command::new(output_file);
     }

From 1a3bda648747e2d332f58988a12bbed1aefd4cda Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Mon, 13 Apr 2020 16:06:51 +0200
Subject: [PATCH 04/10] Miri: let push_frame hook also access and mutate the
 rest of the frame data

---
 src/librustc_mir/const_eval/machine.rs     | 11 +++++---
 src/librustc_mir/interpret/eval_context.rs | 31 +++++++++++++++++-----
 src/librustc_mir/interpret/machine.rs      | 13 +++++----
 src/librustc_mir/transform/const_prop.rs   |  7 +++--
 4 files changed, 44 insertions(+), 18 deletions(-)

diff --git a/src/librustc_mir/const_eval/machine.rs b/src/librustc_mir/const_eval/machine.rs
index e926347147894..ac9ef803d3b6a 100644
--- a/src/librustc_mir/const_eval/machine.rs
+++ b/src/librustc_mir/const_eval/machine.rs
@@ -13,8 +13,8 @@ use rustc_middle::mir::AssertMessage;
 use rustc_span::symbol::Symbol;
 
 use crate::interpret::{
-    self, AllocId, Allocation, GlobalId, ImmTy, InterpCx, InterpResult, Memory, MemoryKind, OpTy,
-    PlaceTy, Pointer, Scalar,
+    self, AllocId, Allocation, Frame, GlobalId, ImmTy, InterpCx, InterpResult, Memory, MemoryKind,
+    OpTy, PlaceTy, Pointer, Scalar,
 };
 
 use super::error::*;
@@ -339,8 +339,11 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter {
     }
 
     #[inline(always)]
-    fn stack_push(_ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
-        Ok(())
+    fn init_frame_extra(
+        _ecx: &mut InterpCx<'mir, 'tcx, Self>,
+        frame: Frame<'mir, 'tcx>,
+    ) -> InterpResult<'tcx, Frame<'mir, 'tcx>> {
+        Ok(frame)
     }
 
     fn before_access_global(
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs
index e0b5f634bf3df..a0c6240a8a0ae 100644
--- a/src/librustc_mir/interpret/eval_context.rs
+++ b/src/librustc_mir/interpret/eval_context.rs
@@ -159,6 +159,21 @@ impl<'tcx, Tag: Copy + 'static> LocalState<'tcx, Tag> {
     }
 }
 
+impl<'mir, 'tcx, Tag> Frame<'mir, 'tcx, Tag> {
+    pub fn with_extra<Extra>(self, extra: Extra) -> Frame<'mir, 'tcx, Tag, Extra> {
+        Frame {
+            body: self.body,
+            instance: self.instance,
+            return_to_block: self.return_to_block,
+            return_place: self.return_place,
+            locals: self.locals,
+            block: self.block,
+            stmt: self.stmt,
+            extra,
+        }
+    }
+}
+
 impl<'mir, 'tcx, Tag, Extra> Frame<'mir, 'tcx, Tag, Extra> {
     /// Return the `SourceInfo` of the current instruction.
     pub fn current_source_info(&self) -> Option<mir::SourceInfo> {
@@ -586,8 +601,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         ::log_settings::settings().indentation += 1;
 
         // first push a stack frame so we have access to the local substs
-        let extra = M::stack_push(self)?;
-        self.stack.push(Frame {
+        let pre_frame = Frame {
             body,
             block: Some(mir::START_BLOCK),
             return_to_block,
@@ -597,8 +611,10 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             locals: IndexVec::new(),
             instance,
             stmt: 0,
-            extra,
-        });
+            extra: (),
+        };
+        let frame = M::init_frame_extra(self, pre_frame)?;
+        self.stack.push(frame);
 
         // don't allocate at all for trivial constants
         if body.local_decls.len() > 1 {
@@ -725,11 +741,12 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         }
 
         // Cleanup: deallocate all locals that are backed by an allocation.
-        for local in frame.locals {
+        for local in &frame.locals {
             self.deallocate_local(local.value)?;
         }
 
-        if M::stack_pop(self, frame.extra, unwinding)? == StackPopJump::NoJump {
+        let return_place = frame.return_place;
+        if M::after_stack_pop(self, frame, unwinding)? == StackPopJump::NoJump {
             // The hook already did everything.
             // We want to skip the `info!` below, hence early return.
             return Ok(());
@@ -743,7 +760,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             // Follow the normal return edge.
             // Validate the return value. Do this after deallocating so that we catch dangling
             // references.
-            if let Some(return_place) = frame.return_place {
+            if let Some(return_place) = return_place {
                 if M::enforce_validity(self) {
                     // Data got changed, better make sure it matches the type!
                     // It is still possible that the return place held invalid data while
diff --git a/src/librustc_mir/interpret/machine.rs b/src/librustc_mir/interpret/machine.rs
index fd67b088c93cf..ffda0334a508f 100644
--- a/src/librustc_mir/interpret/machine.rs
+++ b/src/librustc_mir/interpret/machine.rs
@@ -279,13 +279,16 @@ pub trait Machine<'mir, 'tcx>: Sized {
         Ok(())
     }
 
-    /// Called immediately before a new stack frame got pushed.
-    fn stack_push(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx, Self::FrameExtra>;
+    /// Called immediately before a new stack frame gets pushed.
+    fn init_frame_extra(
+        ecx: &mut InterpCx<'mir, 'tcx, Self>,
+        frame: Frame<'mir, 'tcx, Self::PointerTag>,
+    ) -> InterpResult<'tcx, Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>>;
 
-    /// Called immediately after a stack frame gets popped
-    fn stack_pop(
+    /// Called immediately after a stack frame got popped, but before jumping back to the caller.
+    fn after_stack_pop(
         _ecx: &mut InterpCx<'mir, 'tcx, Self>,
-        _extra: Self::FrameExtra,
+        _frame: Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>,
         _unwinding: bool,
     ) -> InterpResult<'tcx, StackPopJump> {
         // By default, we do not support unwinding from panics
diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs
index 5a00f206a7646..ed5c2543ec6bb 100644
--- a/src/librustc_mir/transform/const_prop.rs
+++ b/src/librustc_mir/transform/const_prop.rs
@@ -287,8 +287,11 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for ConstPropMachine {
     }
 
     #[inline(always)]
-    fn stack_push(_ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
-        Ok(())
+    fn init_frame_extra(
+        _ecx: &mut InterpCx<'mir, 'tcx, Self>,
+        frame: Frame<'mir, 'tcx>,
+    ) -> InterpResult<'tcx, Frame<'mir, 'tcx>> {
+        Ok(frame)
     }
 }
 

From 7b90ff9ae68cc23fe002c92f30a4aaf2039c5a8f Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Mon, 13 Apr 2020 17:07:54 +0200
Subject: [PATCH 05/10] add after_stack_push hook; add public
 ImmTy::from_immediate method, and make ImmTy::imm field private

---
 src/librustc_mir/const_eval/eval_queries.rs | 40 +++++++++++----------
 src/librustc_mir/interpret/eval_context.rs  |  3 +-
 src/librustc_mir/interpret/machine.rs       |  5 +++
 src/librustc_mir/interpret/operand.rs       | 11 ++++--
 src/librustc_mir/interpret/place.rs         |  2 +-
 src/librustc_mir/interpret/terminator.rs    | 10 +++---
 6 files changed, 43 insertions(+), 28 deletions(-)

diff --git a/src/librustc_mir/const_eval/eval_queries.rs b/src/librustc_mir/const_eval/eval_queries.rs
index 97cdb32e2cdf7..33f8397887336 100644
--- a/src/librustc_mir/const_eval/eval_queries.rs
+++ b/src/librustc_mir/const_eval/eval_queries.rs
@@ -1,7 +1,7 @@
 use super::{error_to_const_error, CompileTimeEvalContext, CompileTimeInterpreter, MemoryExtra};
 use crate::interpret::eval_nullary_intrinsic;
 use crate::interpret::{
-    intern_const_alloc_recursive, Allocation, ConstValue, GlobalId, ImmTy, Immediate, InternKind,
+    intern_const_alloc_recursive, Allocation, ConstValue, GlobalId, Immediate, InternKind,
     InterpCx, InterpResult, MPlaceTy, MemoryKind, OpTy, RawConst, RefTracking, Scalar,
     ScalarMaybeUndef, StackPopCleanup,
 };
@@ -147,24 +147,26 @@ pub(super) fn op_to_const<'tcx>(
     match immediate {
         Ok(mplace) => to_const_value(mplace),
         // see comment on `let try_as_immediate` above
-        Err(ImmTy { imm: Immediate::Scalar(x), .. }) => match x {
-            ScalarMaybeUndef::Scalar(s) => ConstValue::Scalar(s),
-            ScalarMaybeUndef::Undef => to_const_value(op.assert_mem_place(ecx)),
-        },
-        Err(ImmTy { imm: Immediate::ScalarPair(a, b), .. }) => {
-            let (data, start) = match a.not_undef().unwrap() {
-                Scalar::Ptr(ptr) => {
-                    (ecx.tcx.alloc_map.lock().unwrap_memory(ptr.alloc_id), ptr.offset.bytes())
-                }
-                Scalar::Raw { .. } => (
-                    ecx.tcx.intern_const_alloc(Allocation::from_byte_aligned_bytes(b"" as &[u8])),
-                    0,
-                ),
-            };
-            let len = b.to_machine_usize(&ecx.tcx.tcx).unwrap();
-            let start = start.try_into().unwrap();
-            let len: usize = len.try_into().unwrap();
-            ConstValue::Slice { data, start, end: start + len }
+        Err(imm) => match *imm {
+            Immediate::Scalar(x) => match x {
+                ScalarMaybeUndef::Scalar(s) => ConstValue::Scalar(s),
+                ScalarMaybeUndef::Undef => to_const_value(op.assert_mem_place(ecx)),
+            },
+            Immediate::ScalarPair(a, b) => {
+                let (data, start) = match a.not_undef().unwrap() {
+                    Scalar::Ptr(ptr) => {
+                        (ecx.tcx.alloc_map.lock().unwrap_memory(ptr.alloc_id), ptr.offset.bytes())
+                    }
+                    Scalar::Raw { .. } => (
+                        ecx.tcx.intern_const_alloc(Allocation::from_byte_aligned_bytes(b"" as &[u8])),
+                        0,
+                    ),
+                };
+                let len = b.to_machine_usize(&ecx.tcx.tcx).unwrap();
+                let start = start.try_into().unwrap();
+                let len: usize = len.try_into().unwrap();
+                ConstValue::Slice { data, start, end: start + len }
+            }
         }
     }
 }
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs
index a0c6240a8a0ae..f111eecb9450e 100644
--- a/src/librustc_mir/interpret/eval_context.rs
+++ b/src/librustc_mir/interpret/eval_context.rs
@@ -646,6 +646,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             self.frame_mut().locals = locals;
         }
 
+        M::after_stack_push(self)?;
         info!("ENTERING({}) {}", self.cur_frame(), self.frame().instance);
 
         if self.stack.len() > *self.tcx.sess.recursion_limit.get() {
@@ -751,7 +752,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             // We want to skip the `info!` below, hence early return.
             return Ok(());
         }
-        // Normal return.
+        // Normal return, figure out where to jump.
         if unwinding {
             // Follow the unwind edge.
             let unwind = next_block.expect("Encountered StackPopCleanup::None when unwinding!");
diff --git a/src/librustc_mir/interpret/machine.rs b/src/librustc_mir/interpret/machine.rs
index ffda0334a508f..3c7cb73610ea6 100644
--- a/src/librustc_mir/interpret/machine.rs
+++ b/src/librustc_mir/interpret/machine.rs
@@ -285,6 +285,11 @@ pub trait Machine<'mir, 'tcx>: Sized {
         frame: Frame<'mir, 'tcx, Self::PointerTag>,
     ) -> InterpResult<'tcx, Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>>;
 
+    /// Called immediately after a stack frame got pushed and its locals got initialized.
+    fn after_stack_push(_ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
+        Ok(())
+    }
+
     /// Called immediately after a stack frame got popped, but before jumping back to the caller.
     fn after_stack_pop(
         _ecx: &mut InterpCx<'mir, 'tcx, Self>,
diff --git a/src/librustc_mir/interpret/operand.rs b/src/librustc_mir/interpret/operand.rs
index 3741f31927e94..893f4c1db7e0a 100644
--- a/src/librustc_mir/interpret/operand.rs
+++ b/src/librustc_mir/interpret/operand.rs
@@ -87,7 +87,7 @@ impl<'tcx, Tag> Immediate<Tag> {
 // as input for binary and cast operations.
 #[derive(Copy, Clone, Debug)]
 pub struct ImmTy<'tcx, Tag = ()> {
-    pub(crate) imm: Immediate<Tag>,
+    imm: Immediate<Tag>,
     pub layout: TyAndLayout<'tcx>,
 }
 
@@ -183,6 +183,11 @@ impl<'tcx, Tag: Copy> ImmTy<'tcx, Tag> {
         ImmTy { imm: val.into(), layout }
     }
 
+    #[inline]
+    pub fn from_immediate(imm: Immediate<Tag>, layout: TyAndLayout<'tcx>) -> Self {
+        ImmTy { imm, layout }
+    }
+
     #[inline]
     pub fn try_from_uint(i: impl Into<u128>, layout: TyAndLayout<'tcx>) -> Option<Self> {
         Some(Self::from_scalar(Scalar::try_from_uint(i, layout.size)?, layout))
@@ -424,7 +429,9 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         Ok(OpTy { op, layout })
     }
 
-    /// Every place can be read from, so we can turn them into an operand
+    /// Every place can be read from, so we can turn them into an operand.
+    /// This will definitely return `Indirect` if the place is a `Ptr`, i.e., this
+    /// will never actually read from memory.
     #[inline(always)]
     pub fn place_to_op(
         &self,
diff --git a/src/librustc_mir/interpret/place.rs b/src/librustc_mir/interpret/place.rs
index 828df9a0930f5..9ac4b3551fc43 100644
--- a/src/librustc_mir/interpret/place.rs
+++ b/src/librustc_mir/interpret/place.rs
@@ -247,7 +247,7 @@ impl<'tcx, Tag: ::std::fmt::Debug + Copy> OpTy<'tcx, Tag> {
             Operand::Immediate(_) if self.layout.is_zst() => {
                 Ok(MPlaceTy::dangling(self.layout, cx))
             }
-            Operand::Immediate(imm) => Err(ImmTy { imm, layout: self.layout }),
+            Operand::Immediate(imm) => Err(ImmTy::from_immediate(imm, self.layout)),
         }
     }
 
diff --git a/src/librustc_mir/interpret/terminator.rs b/src/librustc_mir/interpret/terminator.rs
index 2d8551b2bbf1e..49fee1bddcb6d 100644
--- a/src/librustc_mir/interpret/terminator.rs
+++ b/src/librustc_mir/interpret/terminator.rs
@@ -407,7 +407,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 let this_receiver_ptr = self.layout_of(receiver_ptr_ty)?.field(self, 0)?;
                 // Adjust receiver argument.
                 args[0] =
-                    OpTy::from(ImmTy { layout: this_receiver_ptr, imm: receiver_place.ptr.into() });
+                    OpTy::from(ImmTy::from_immediate(receiver_place.ptr.into(), this_receiver_ptr));
                 trace!("Patched self operand to {:#?}", args[0]);
                 // recurse with concrete function
                 self.eval_fn_call(drop_fn, caller_abi, &args, ret, unwind)
@@ -436,10 +436,10 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             _ => (instance, place),
         };
 
-        let arg = ImmTy {
-            imm: place.to_ref(),
-            layout: self.layout_of(self.tcx.mk_mut_ptr(place.layout.ty))?,
-        };
+        let arg = ImmTy::from_immediate(
+            place.to_ref(),
+            self.layout_of(self.tcx.mk_mut_ptr(place.layout.ty))?,
+        );
 
         let ty = self.tcx.mk_unit(); // return type is ()
         let dest = MPlaceTy::dangling(self.layout_of(ty)?, self);

From f2d4c93c6c56d8cfe1d69646ba1f788823e6bc35 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Mon, 13 Apr 2020 18:05:05 +0200
Subject: [PATCH 06/10] fmt

---
 src/librustc_mir/const_eval/eval_queries.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/librustc_mir/const_eval/eval_queries.rs b/src/librustc_mir/const_eval/eval_queries.rs
index 33f8397887336..3f0774767fd7a 100644
--- a/src/librustc_mir/const_eval/eval_queries.rs
+++ b/src/librustc_mir/const_eval/eval_queries.rs
@@ -158,7 +158,8 @@ pub(super) fn op_to_const<'tcx>(
                         (ecx.tcx.alloc_map.lock().unwrap_memory(ptr.alloc_id), ptr.offset.bytes())
                     }
                     Scalar::Raw { .. } => (
-                        ecx.tcx.intern_const_alloc(Allocation::from_byte_aligned_bytes(b"" as &[u8])),
+                        ecx.tcx
+                            .intern_const_alloc(Allocation::from_byte_aligned_bytes(b"" as &[u8])),
                         0,
                     ),
                 };
@@ -167,7 +168,7 @@ pub(super) fn op_to_const<'tcx>(
                 let len: usize = len.try_into().unwrap();
                 ConstValue::Slice { data, start, end: start + len }
             }
-        }
+        },
     }
 }
 

From a0d4c743ab7333af236e985d4e076cdc85249cf9 Mon Sep 17 00:00:00 2001
From: Mark Rousskov <mark.simulacrum@gmail.com>
Date: Sun, 12 Apr 2020 22:01:15 -0400
Subject: [PATCH 07/10] Remove unused single_step flag

This appears to have never been used ever since its introduction in 61c7569d4 --
the plugin discussed on the PR introducing that commit, 34811, never
materialized.

It's also simple to readd in the current scheme, but given that macro expansion
is already quite complicated, additional useless state seems good to remove
while we're not using it.
---
 src/librustc_expand/expand.rs | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/librustc_expand/expand.rs b/src/librustc_expand/expand.rs
index 51208906c2f2d..7473c890c5ab9 100644
--- a/src/librustc_expand/expand.rs
+++ b/src/librustc_expand/expand.rs
@@ -507,9 +507,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 expanded_fragments.push(Vec::new());
             }
             expanded_fragments[depth - 1].push((expn_id, expanded_fragment));
-            if !self.cx.ecfg.single_step {
-                invocations.extend(new_invocations.into_iter().rev());
-            }
+            invocations.extend(new_invocations.into_iter().rev());
         }
 
         self.cx.current_expansion = orig_expansion_data;
@@ -1819,7 +1817,6 @@ pub struct ExpansionConfig<'feat> {
     pub recursion_limit: usize,
     pub trace_mac: bool,
     pub should_test: bool, // If false, strip `#[test]` nodes
-    pub single_step: bool,
     pub keep_macs: bool,
 }
 
@@ -1831,7 +1828,6 @@ impl<'feat> ExpansionConfig<'feat> {
             recursion_limit: 1024,
             trace_mac: false,
             should_test: false,
-            single_step: false,
             keep_macs: false,
         }
     }

From 31eff9af3fd819061d3a573ba3b93e0cc3bfeec3 Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Tue, 14 Apr 2020 08:54:05 -0700
Subject: [PATCH 08/10] Update books

---
 src/doc/book            | 2 +-
 src/doc/edition-guide   | 2 +-
 src/doc/embedded-book   | 2 +-
 src/doc/reference       | 2 +-
 src/doc/rust-by-example | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/doc/book b/src/doc/book
index c8841f2841a2d..f5db319e0b19c 160000
--- a/src/doc/book
+++ b/src/doc/book
@@ -1 +1 @@
-Subproject commit c8841f2841a2d26124319ddadd1b6a245f9a1856
+Subproject commit f5db319e0b19c22964398d56bc63103d669e1bba
diff --git a/src/doc/edition-guide b/src/doc/edition-guide
index 37f9e68484111..8204c1d123472 160000
--- a/src/doc/edition-guide
+++ b/src/doc/edition-guide
@@ -1 +1 @@
-Subproject commit 37f9e6848411188a1062ead1bd8ebe4b8aa16899
+Subproject commit 8204c1d123472cd17f0c1c5c77300ae802eb0271
diff --git a/src/doc/embedded-book b/src/doc/embedded-book
index d22a9c487c780..668fb07b6160b 160000
--- a/src/doc/embedded-book
+++ b/src/doc/embedded-book
@@ -1 +1 @@
-Subproject commit d22a9c487c78095afc4584f1d9b4ec43529d713c
+Subproject commit 668fb07b6160b9c468f598e839c1e044db65de30
diff --git a/src/doc/reference b/src/doc/reference
index 89dd146154474..3ce94caed4cf9 160000
--- a/src/doc/reference
+++ b/src/doc/reference
@@ -1 +1 @@
-Subproject commit 89dd146154474559536d5d4049a03831c501deea
+Subproject commit 3ce94caed4cf967106c51ae86be5e098f7875f11
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
index a6638463efc76..c106d1683c3a2 160000
--- a/src/doc/rust-by-example
+++ b/src/doc/rust-by-example
@@ -1 +1 @@
-Subproject commit a6638463efc7631bc0e8dc67ccd256d4e1b61f1a
+Subproject commit c106d1683c3a2b0960f0f0fb01728cbb19807332

From 2765f426da76fd7b7b9bd377de7f92dd181387c0 Mon Sep 17 00:00:00 2001
From: Bastian Kauschke <bastian_kauschke@hotmail.de>
Date: Tue, 14 Apr 2020 17:29:26 +0200
Subject: [PATCH 09/10] cleanup `is_expr_delims_necessary`

---
 src/librustc_lint/unused.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/librustc_lint/unused.rs b/src/librustc_lint/unused.rs
index aa7c87e9f7bd2..3e1e9cc70aa11 100644
--- a/src/librustc_lint/unused.rs
+++ b/src/librustc_lint/unused.rs
@@ -384,7 +384,7 @@ trait UnusedDelimLint {
     fn is_expr_delims_necessary(inner: &ast::Expr, followed_by_block: bool) -> bool {
         followed_by_block
             && match inner.kind {
-                ast::ExprKind::Ret(_) | ast::ExprKind::Break(..) => true,
+                ExprKind::Ret(_) | ExprKind::Break(..) => true,
                 _ => parser::contains_exterior_struct_lit(&inner),
             }
     }

From 81a3cd7278f6117401b6b441485154e6ecf2f8c9 Mon Sep 17 00:00:00 2001
From: Bastian Kauschke <bastian_kauschke@hotmail.de>
Date: Tue, 14 Apr 2020 17:45:00 +0200
Subject: [PATCH 10/10] allow try as scrutinee, e.g. `match try ...`

---
 src/librustc_parse/parser/expr.rs             |  8 ++--
 src/test/ui/try-block/try-block-in-match.rs   |  6 ++-
 .../ui/try-block/try-block-in-match.stderr    | 10 -----
 src/test/ui/try-block/try-block-in-while.rs   |  3 +-
 .../ui/try-block/try-block-in-while.stderr    |  9 ++--
 .../ui/try-block/try-block-unused-delims.rs   | 28 ++++++++++++
 .../try-block/try-block-unused-delims.stderr  | 44 +++++++++++++++++++
 7 files changed, 88 insertions(+), 20 deletions(-)
 delete mode 100644 src/test/ui/try-block/try-block-in-match.stderr
 create mode 100644 src/test/ui/try-block/try-block-unused-delims.rs
 create mode 100644 src/test/ui/try-block/try-block-unused-delims.stderr

diff --git a/src/librustc_parse/parser/expr.rs b/src/librustc_parse/parser/expr.rs
index cbff99f8da612..4e3c5fa63de2c 100644
--- a/src/librustc_parse/parser/expr.rs
+++ b/src/librustc_parse/parser/expr.rs
@@ -1846,11 +1846,9 @@ impl<'a> Parser<'a> {
     }
 
     fn is_try_block(&self) -> bool {
-        self.token.is_keyword(kw::Try) &&
-        self.look_ahead(1, |t| *t == token::OpenDelim(token::Brace)) &&
-        self.token.uninterpolated_span().rust_2018() &&
-        // Prevent `while try {} {}`, `if try {} {} else {}`, etc.
-        !self.restrictions.contains(Restrictions::NO_STRUCT_LITERAL)
+        self.token.is_keyword(kw::Try)
+            && self.look_ahead(1, |t| *t == token::OpenDelim(token::Brace))
+            && self.token.uninterpolated_span().rust_2018()
     }
 
     /// Parses an `async move? {...}` expression.
diff --git a/src/test/ui/try-block/try-block-in-match.rs b/src/test/ui/try-block/try-block-in-match.rs
index bce0d0340b658..cd0b967e79d07 100644
--- a/src/test/ui/try-block/try-block-in-match.rs
+++ b/src/test/ui/try-block/try-block-in-match.rs
@@ -1,7 +1,11 @@
+// run-pass
 // compile-flags: --edition 2018
 
 #![feature(try_blocks)]
 
 fn main() {
-    match try { false } { _ => {} } //~ ERROR expected expression, found reserved keyword `try`
+    match try { } {
+        Err(()) => (),
+        Ok(()) => (),
+    }
 }
diff --git a/src/test/ui/try-block/try-block-in-match.stderr b/src/test/ui/try-block/try-block-in-match.stderr
deleted file mode 100644
index 936e0fe19bafe..0000000000000
--- a/src/test/ui/try-block/try-block-in-match.stderr
+++ /dev/null
@@ -1,10 +0,0 @@
-error: expected expression, found reserved keyword `try`
-  --> $DIR/try-block-in-match.rs:6:11
-   |
-LL |     match try { false } { _ => {} }
-   |     ----- ^^^ expected expression
-   |     |
-   |     while parsing this match expression
-
-error: aborting due to previous error
-
diff --git a/src/test/ui/try-block/try-block-in-while.rs b/src/test/ui/try-block/try-block-in-while.rs
index 98af796dd3780..33d2723651929 100644
--- a/src/test/ui/try-block/try-block-in-while.rs
+++ b/src/test/ui/try-block/try-block-in-while.rs
@@ -3,5 +3,6 @@
 #![feature(try_blocks)]
 
 fn main() {
-    while try { false } {} //~ ERROR expected expression, found reserved keyword `try`
+    while try { false } {}
+    //~^ ERROR the trait bound `bool: std::ops::Try` is not satisfied
 }
diff --git a/src/test/ui/try-block/try-block-in-while.stderr b/src/test/ui/try-block/try-block-in-while.stderr
index 026df15eb877a..ac41ddfd8c042 100644
--- a/src/test/ui/try-block/try-block-in-while.stderr
+++ b/src/test/ui/try-block/try-block-in-while.stderr
@@ -1,8 +1,11 @@
-error: expected expression, found reserved keyword `try`
-  --> $DIR/try-block-in-while.rs:6:11
+error[E0277]: the trait bound `bool: std::ops::Try` is not satisfied
+  --> $DIR/try-block-in-while.rs:6:15
    |
 LL |     while try { false } {}
-   |           ^^^ expected expression
+   |               ^^^^^^^^^ the trait `std::ops::Try` is not implemented for `bool`
+   |
+   = note: required by `std::ops::Try::from_ok`
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/try-block/try-block-unused-delims.rs b/src/test/ui/try-block/try-block-unused-delims.rs
new file mode 100644
index 0000000000000..0b767eb2dad77
--- /dev/null
+++ b/src/test/ui/try-block/try-block-unused-delims.rs
@@ -0,0 +1,28 @@
+// check-pass
+// compile-flags: --edition 2018
+
+#![feature(try_blocks)]
+#![warn(unused_parens, unused_braces)]
+
+fn consume<T>(_: Result<T, T>) -> T { todo!() }
+
+fn main() {
+    consume((try {}));
+    //~^ WARN unnecessary parentheses
+
+    consume({ try {} });
+    //~^ WARN unnecessary braces
+
+    match (try {}) {
+        //~^ WARN unnecessary parentheses
+        Ok(()) | Err(()) => (),
+    }
+
+    if let Err(()) = (try {}) {}
+    //~^ WARN unnecessary parentheses
+
+    match (try {}) {
+        //~^ WARN unnecessary parentheses
+        Ok(()) | Err(()) => (),
+    }
+}
diff --git a/src/test/ui/try-block/try-block-unused-delims.stderr b/src/test/ui/try-block/try-block-unused-delims.stderr
new file mode 100644
index 0000000000000..5c7602ee0ab12
--- /dev/null
+++ b/src/test/ui/try-block/try-block-unused-delims.stderr
@@ -0,0 +1,44 @@
+warning: unnecessary parentheses around function argument
+  --> $DIR/try-block-unused-delims.rs:10:13
+   |
+LL |     consume((try {}));
+   |             ^^^^^^^^ help: remove these parentheses
+   |
+note: the lint level is defined here
+  --> $DIR/try-block-unused-delims.rs:5:9
+   |
+LL | #![warn(unused_parens, unused_braces)]
+   |         ^^^^^^^^^^^^^
+
+warning: unnecessary braces around function argument
+  --> $DIR/try-block-unused-delims.rs:13:13
+   |
+LL |     consume({ try {} });
+   |             ^^^^^^^^^^ help: remove these braces
+   |
+note: the lint level is defined here
+  --> $DIR/try-block-unused-delims.rs:5:24
+   |
+LL | #![warn(unused_parens, unused_braces)]
+   |                        ^^^^^^^^^^^^^
+
+warning: unnecessary parentheses around `match` scrutinee expression
+  --> $DIR/try-block-unused-delims.rs:16:11
+   |
+LL |     match (try {}) {
+   |           ^^^^^^^^ help: remove these parentheses
+
+warning: unnecessary parentheses around `let` scrutinee expression
+  --> $DIR/try-block-unused-delims.rs:21:22
+   |
+LL |     if let Err(()) = (try {}) {}
+   |                      ^^^^^^^^ help: remove these parentheses
+
+warning: unnecessary parentheses around `match` scrutinee expression
+  --> $DIR/try-block-unused-delims.rs:24:11
+   |
+LL |     match (try {}) {
+   |           ^^^^^^^^ help: remove these parentheses
+
+warning: 5 warnings emitted
+