Rollup merge of #69002 - RalfJung:miri-op-overflow, r=oli-obk,wesleywiser

miri: improve and simplify overflow detection

This simplifies the overflow detection for signed binary operators, and adds overflow detection to unary operators so that const-prop doesn't have to crudely hand-roll that.

It also fixes some bugs in the operator implementation that however, I think, were not observable.

r? @oli-obk @wesleywiser

4 files changed, 117 insertions, 39 deletions

diff --git a/src/test/ui/issues/issue-8460-const.rs b/src/test/ui/issues/issue-8460-const.rs
index c18a0d4d6cb..5866cef2d2c 100644
--- a/src/test/ui/issues/issue-8460-const.rs
+++ b/src/test/ui/issues/issue-8460-const.rs
@@ -3,7 +3,7 @@
 
 #![deny(const_err)]
 
-use std::{isize, i8, i16, i32, i64};
+use std::{isize, i8, i16, i32, i64, i128};
 use std::thread;
 
 fn main() {
@@ -22,6 +22,9 @@ fn main() {
     assert!(thread::spawn(move|| { i64::MIN / -1; }).join().is_err());
     //~^ ERROR attempt to divide with overflow
     //~| ERROR this expression will panic at runtime
+    assert!(thread::spawn(move|| { i128::MIN / -1; }).join().is_err());
+    //~^ ERROR attempt to divide with overflow
+    //~| ERROR this expression will panic at runtime
     assert!(thread::spawn(move|| { 1isize / 0; }).join().is_err());
     //~^ ERROR attempt to divide by zero
     assert!(thread::spawn(move|| { 1i8 / 0; }).join().is_err());
@@ -32,6 +35,8 @@ fn main() {
     //~^ ERROR attempt to divide by zero
     assert!(thread::spawn(move|| { 1i64 / 0; }).join().is_err());
     //~^ ERROR attempt to divide by zero
+    assert!(thread::spawn(move|| { 1i128 / 0; }).join().is_err());
+    //~^ ERROR attempt to divide by zero
     assert!(thread::spawn(move|| { isize::MIN % -1; }).join().is_err());
     //~^ ERROR attempt to calculate the remainder with overflow
     //~| ERROR this expression will panic at runtime
@@ -47,6 +52,9 @@ fn main() {
     assert!(thread::spawn(move|| { i64::MIN % -1; }).join().is_err());
     //~^ ERROR attempt to calculate the remainder with overflow
     //~| ERROR this expression will panic at runtime
+    assert!(thread::spawn(move|| { i128::MIN % -1; }).join().is_err());
+    //~^ ERROR attempt to calculate the remainder with overflow
+    //~| ERROR this expression will panic at runtime
     assert!(thread::spawn(move|| { 1isize % 0; }).join().is_err());
     //~^ ERROR attempt to calculate the remainder with a divisor of zero
     assert!(thread::spawn(move|| { 1i8 % 0; }).join().is_err());
@@ -57,4 +65,6 @@ fn main() {
     //~^ ERROR attempt to calculate the remainder with a divisor of zero
     assert!(thread::spawn(move|| { 1i64 % 0; }).join().is_err());
     //~^ ERROR attempt to calculate the remainder with a divisor of zero
+    assert!(thread::spawn(move|| { 1i128 % 0; }).join().is_err());
+    //~^ ERROR attempt to calculate the remainder with a divisor of zero
 }
diff --git a/src/test/ui/issues/issue-8460-const.stderr b/src/test/ui/issues/issue-8460-const.stderr
index 6b1d74094a1..d7373948cb9 100644
--- a/src/test/ui/issues/issue-8460-const.stderr
+++ b/src/test/ui/issues/issue-8460-const.stderr
@@ -64,125 +64,161 @@ error: this expression will panic at runtime
 LL |     assert!(thread::spawn(move|| { i64::MIN / -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^ attempt to divide with overflow
 
-error: attempt to divide by zero
+error: attempt to divide with overflow
+  --> $DIR/issue-8460-const.rs:25:36
+   |
+LL |     assert!(thread::spawn(move|| { i128::MIN / -1; }).join().is_err());
+   |                                    ^^^^^^^^^^^^^^
+
+error: this expression will panic at runtime
   --> $DIR/issue-8460-const.rs:25:36
    |
+LL |     assert!(thread::spawn(move|| { i128::MIN / -1; }).join().is_err());
+   |                                    ^^^^^^^^^^^^^^ attempt to divide with overflow
+
+error: attempt to divide by zero
+  --> $DIR/issue-8460-const.rs:28:36
+   |
 LL |     assert!(thread::spawn(move|| { 1isize / 0; }).join().is_err());
    |                                    ^^^^^^^^^^
 
 error: attempt to divide by zero
-  --> $DIR/issue-8460-const.rs:27:36
+  --> $DIR/issue-8460-const.rs:30:36
    |
 LL |     assert!(thread::spawn(move|| { 1i8 / 0; }).join().is_err());
    |                                    ^^^^^^^
 
 error: attempt to divide by zero
-  --> $DIR/issue-8460-const.rs:29:36
+  --> $DIR/issue-8460-const.rs:32:36
    |
 LL |     assert!(thread::spawn(move|| { 1i16 / 0; }).join().is_err());
    |                                    ^^^^^^^^
 
 error: attempt to divide by zero
-  --> $DIR/issue-8460-const.rs:31:36
+  --> $DIR/issue-8460-const.rs:34:36
    |
 LL |     assert!(thread::spawn(move|| { 1i32 / 0; }).join().is_err());
    |                                    ^^^^^^^^
 
 error: attempt to divide by zero
-  --> $DIR/issue-8460-const.rs:33:36
+  --> $DIR/issue-8460-const.rs:36:36
    |
 LL |     assert!(thread::spawn(move|| { 1i64 / 0; }).join().is_err());
    |                                    ^^^^^^^^
 
+error: attempt to divide by zero
+  --> $DIR/issue-8460-const.rs:38:36
+   |
+LL |     assert!(thread::spawn(move|| { 1i128 / 0; }).join().is_err());
+   |                                    ^^^^^^^^^
+
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const.rs:35:36
+  --> $DIR/issue-8460-const.rs:40:36
    |
 LL |     assert!(thread::spawn(move|| { isize::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^^^
 
 error: this expression will panic at runtime
-  --> $DIR/issue-8460-const.rs:35:36
+  --> $DIR/issue-8460-const.rs:40:36
    |
 LL |     assert!(thread::spawn(move|| { isize::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^^^ attempt to calculate the remainder with overflow
 
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const.rs:38:36
+  --> $DIR/issue-8460-const.rs:43:36
    |
 LL |     assert!(thread::spawn(move|| { i8::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^
 
 error: this expression will panic at runtime
-  --> $DIR/issue-8460-const.rs:38:36
+  --> $DIR/issue-8460-const.rs:43:36
    |
 LL |     assert!(thread::spawn(move|| { i8::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^ attempt to calculate the remainder with overflow
 
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const.rs:41:36
+  --> $DIR/issue-8460-const.rs:46:36
    |
 LL |     assert!(thread::spawn(move|| { i16::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^
 
 error: this expression will panic at runtime
-  --> $DIR/issue-8460-const.rs:41:36
+  --> $DIR/issue-8460-const.rs:46:36
    |
 LL |     assert!(thread::spawn(move|| { i16::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^ attempt to calculate the remainder with overflow
 
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const.rs:44:36
+  --> $DIR/issue-8460-const.rs:49:36
    |
 LL |     assert!(thread::spawn(move|| { i32::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^
 
 error: this expression will panic at runtime
-  --> $DIR/issue-8460-const.rs:44:36
+  --> $DIR/issue-8460-const.rs:49:36
    |
 LL |     assert!(thread::spawn(move|| { i32::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^ attempt to calculate the remainder with overflow
 
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const.rs:47:36
+  --> $DIR/issue-8460-const.rs:52:36
    |
 LL |     assert!(thread::spawn(move|| { i64::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^
 
 error: this expression will panic at runtime
-  --> $DIR/issue-8460-const.rs:47:36
+  --> $DIR/issue-8460-const.rs:52:36
    |
 LL |     assert!(thread::spawn(move|| { i64::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^ attempt to calculate the remainder with overflow
 
+error: attempt to calculate the remainder with overflow
+  --> $DIR/issue-8460-const.rs:55:36
+   |
+LL |     assert!(thread::spawn(move|| { i128::MIN % -1; }).join().is_err());
+   |                                    ^^^^^^^^^^^^^^
+
+error: this expression will panic at runtime
+  --> $DIR/issue-8460-const.rs:55:36
+   |
+LL |     assert!(thread::spawn(move|| { i128::MIN % -1; }).join().is_err());
+   |                                    ^^^^^^^^^^^^^^ attempt to calculate the remainder with overflow
+
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const.rs:50:36
+  --> $DIR/issue-8460-const.rs:58:36
    |
 LL |     assert!(thread::spawn(move|| { 1isize % 0; }).join().is_err());
    |                                    ^^^^^^^^^^
 
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const.rs:52:36
+  --> $DIR/issue-8460-const.rs:60:36
    |
 LL |     assert!(thread::spawn(move|| { 1i8 % 0; }).join().is_err());
    |                                    ^^^^^^^
 
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const.rs:54:36
+  --> $DIR/issue-8460-const.rs:62:36
    |
 LL |     assert!(thread::spawn(move|| { 1i16 % 0; }).join().is_err());
    |                                    ^^^^^^^^
 
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const.rs:56:36
+  --> $DIR/issue-8460-const.rs:64:36
    |
 LL |     assert!(thread::spawn(move|| { 1i32 % 0; }).join().is_err());
    |                                    ^^^^^^^^
 
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const.rs:58:36
+  --> $DIR/issue-8460-const.rs:66:36
    |
 LL |     assert!(thread::spawn(move|| { 1i64 % 0; }).join().is_err());
    |                                    ^^^^^^^^
 
-error: aborting due to 30 previous errors
+error: attempt to calculate the remainder with a divisor of zero
+  --> $DIR/issue-8460-const.rs:68:36
+   |
+LL |     assert!(thread::spawn(move|| { 1i128 % 0; }).join().is_err());
+   |                                    ^^^^^^^^^
+
+error: aborting due to 36 previous errors
 
diff --git a/src/test/ui/issues/issue-8460-const2.rs b/src/test/ui/issues/issue-8460-const2.rs
index 0ca850abc1b..afea859bb65 100644
--- a/src/test/ui/issues/issue-8460-const2.rs
+++ b/src/test/ui/issues/issue-8460-const2.rs
@@ -3,7 +3,7 @@
 
 #![deny(const_err)]
 
-use std::{isize, i8, i16, i32, i64};
+use std::{isize, i8, i16, i32, i64, i128};
 use std::thread;
 
 fn main() {
@@ -17,6 +17,8 @@ fn main() {
     //~^ ERROR attempt to divide with overflow
     assert!(thread::spawn(move|| { i64::MIN / -1; }).join().is_err());
     //~^ ERROR attempt to divide with overflow
+    assert!(thread::spawn(move|| { i128::MIN / -1; }).join().is_err());
+    //~^ ERROR attempt to divide with overflow
     assert!(thread::spawn(move|| { 1isize / 0; }).join().is_err());
     //~^ ERROR attempt to divide by zero
     assert!(thread::spawn(move|| { 1i8 / 0; }).join().is_err());
@@ -27,6 +29,8 @@ fn main() {
     //~^ ERROR attempt to divide by zero
     assert!(thread::spawn(move|| { 1i64 / 0; }).join().is_err());
     //~^ ERROR attempt to divide by zero
+    assert!(thread::spawn(move|| { 1i128 / 0; }).join().is_err());
+    //~^ ERROR attempt to divide by zero
     assert!(thread::spawn(move|| { isize::MIN % -1; }).join().is_err());
     //~^ ERROR attempt to calculate the remainder with overflow
     assert!(thread::spawn(move|| { i8::MIN % -1; }).join().is_err());
@@ -37,6 +41,8 @@ fn main() {
     //~^ ERROR attempt to calculate the remainder with overflow
     assert!(thread::spawn(move|| { i64::MIN % -1; }).join().is_err());
     //~^ ERROR attempt to calculate the remainder with overflow
+    assert!(thread::spawn(move|| { i128::MIN % -1; }).join().is_err());
+    //~^ ERROR attempt to calculate the remainder with overflow
     assert!(thread::spawn(move|| { 1isize % 0; }).join().is_err());
     //~^ ERROR attempt to calculate the remainder with a divisor of zero
     assert!(thread::spawn(move|| { 1i8 % 0; }).join().is_err());
@@ -47,4 +53,6 @@ fn main() {
     //~^ ERROR attempt to calculate the remainder with a divisor of zero
     assert!(thread::spawn(move|| { 1i64 % 0; }).join().is_err());
     //~^ ERROR attempt to calculate the remainder with a divisor of zero
+    assert!(thread::spawn(move|| { 1i128 % 0; }).join().is_err());
+    //~^ ERROR attempt to calculate the remainder with a divisor of zero
 }
diff --git a/src/test/ui/issues/issue-8460-const2.stderr b/src/test/ui/issues/issue-8460-const2.stderr
index 63b9123e950..e25d560fe0c 100644
--- a/src/test/ui/issues/issue-8460-const2.stderr
+++ b/src/test/ui/issues/issue-8460-const2.stderr
@@ -34,95 +34,119 @@ error: attempt to divide with overflow
 LL |     assert!(thread::spawn(move|| { i64::MIN / -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^
 
-error: attempt to divide by zero
+error: attempt to divide with overflow
   --> $DIR/issue-8460-const2.rs:20:36
    |
+LL |     assert!(thread::spawn(move|| { i128::MIN / -1; }).join().is_err());
+   |                                    ^^^^^^^^^^^^^^
+
+error: attempt to divide by zero
+  --> $DIR/issue-8460-const2.rs:22:36
+   |
 LL |     assert!(thread::spawn(move|| { 1isize / 0; }).join().is_err());
    |                                    ^^^^^^^^^^
 
 error: attempt to divide by zero
-  --> $DIR/issue-8460-const2.rs:22:36
+  --> $DIR/issue-8460-const2.rs:24:36
    |
 LL |     assert!(thread::spawn(move|| { 1i8 / 0; }).join().is_err());
    |                                    ^^^^^^^
 
 error: attempt to divide by zero
-  --> $DIR/issue-8460-const2.rs:24:36
+  --> $DIR/issue-8460-const2.rs:26:36
    |
 LL |     assert!(thread::spawn(move|| { 1i16 / 0; }).join().is_err());
    |                                    ^^^^^^^^
 
 error: attempt to divide by zero
-  --> $DIR/issue-8460-const2.rs:26:36
+  --> $DIR/issue-8460-const2.rs:28:36
    |
 LL |     assert!(thread::spawn(move|| { 1i32 / 0; }).join().is_err());
    |                                    ^^^^^^^^
 
 error: attempt to divide by zero
-  --> $DIR/issue-8460-const2.rs:28:36
+  --> $DIR/issue-8460-const2.rs:30:36
    |
 LL |     assert!(thread::spawn(move|| { 1i64 / 0; }).join().is_err());
    |                                    ^^^^^^^^
 
+error: attempt to divide by zero
+  --> $DIR/issue-8460-const2.rs:32:36
+   |
+LL |     assert!(thread::spawn(move|| { 1i128 / 0; }).join().is_err());
+   |                                    ^^^^^^^^^
+
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const2.rs:30:36
+  --> $DIR/issue-8460-const2.rs:34:36
    |
 LL |     assert!(thread::spawn(move|| { isize::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^^^
 
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const2.rs:32:36
+  --> $DIR/issue-8460-const2.rs:36:36
    |
 LL |     assert!(thread::spawn(move|| { i8::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^
 
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const2.rs:34:36
+  --> $DIR/issue-8460-const2.rs:38:36
    |
 LL |     assert!(thread::spawn(move|| { i16::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^
 
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const2.rs:36:36
+  --> $DIR/issue-8460-const2.rs:40:36
    |
 LL |     assert!(thread::spawn(move|| { i32::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^
 
 error: attempt to calculate the remainder with overflow
-  --> $DIR/issue-8460-const2.rs:38:36
+  --> $DIR/issue-8460-const2.rs:42:36
    |
 LL |     assert!(thread::spawn(move|| { i64::MIN % -1; }).join().is_err());
    |                                    ^^^^^^^^^^^^^
 
+error: attempt to calculate the remainder with overflow
+  --> $DIR/issue-8460-const2.rs:44:36
+   |
+LL |     assert!(thread::spawn(move|| { i128::MIN % -1; }).join().is_err());
+   |                                    ^^^^^^^^^^^^^^
+
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const2.rs:40:36
+  --> $DIR/issue-8460-const2.rs:46:36
    |
 LL |     assert!(thread::spawn(move|| { 1isize % 0; }).join().is_err());
    |                                    ^^^^^^^^^^
 
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const2.rs:42:36
+  --> $DIR/issue-8460-const2.rs:48:36
    |
 LL |     assert!(thread::spawn(move|| { 1i8 % 0; }).join().is_err());
    |                                    ^^^^^^^
 
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const2.rs:44:36
+  --> $DIR/issue-8460-const2.rs:50:36
    |
 LL |     assert!(thread::spawn(move|| { 1i16 % 0; }).join().is_err());
    |                                    ^^^^^^^^
 
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const2.rs:46:36
+  --> $DIR/issue-8460-const2.rs:52:36
    |
 LL |     assert!(thread::spawn(move|| { 1i32 % 0; }).join().is_err());
    |                                    ^^^^^^^^
 
 error: attempt to calculate the remainder with a divisor of zero
-  --> $DIR/issue-8460-const2.rs:48:36
+  --> $DIR/issue-8460-const2.rs:54:36
    |
 LL |     assert!(thread::spawn(move|| { 1i64 % 0; }).join().is_err());
    |                                    ^^^^^^^^
 
-error: aborting due to 20 previous errors
+error: attempt to calculate the remainder with a divisor of zero
+  --> $DIR/issue-8460-const2.rs:56:36
+   |
+LL |     assert!(thread::spawn(move|| { 1i128 % 0; }).join().is_err());
+   |                                    ^^^^^^^^^
+
+error: aborting due to 24 previous errors